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TRADITIONAL POSTER Give the Dog a Bone Hall B Monday 14:00-16:00 784. Preliminary In-Vivo Bone Quantification Results Using MR and PQCT Victor Rakesh Lazar1, Gary P. Liney2, David J. Manton1, Peter Gibbs1, Martin Lowry1, Celia L. Gregson3, Joern Rittweger4, Sue Steel5, Chris Langton6, J H. Tobias3, Lindsay W. Turnbull1 1Centre for MR Investigations, University of Hull, Hull, North Humberside, United Kingdom; 2Radiotherapy Physics, University of Hull, Hull, North Humberside, United Kingdom; 3Academic Rheumatology, University of Bristol, Bristol, United Kingdom; 4Excercise and Sports Medicine, Manchester Metropolitan University, Manchester, United Kingdom; 5Centre for Metabolic Bone Disease, Hull Royal Infirmary, Hull, North Humberside, United Kingdom; 6School of Physical and Chemical Sciences, Queensland University of Technology, Australia Bone quantification is commonly measured using DEXA and pQCT. Research in MRI and MRS have shown promising potential in the quantification of bones. Our work was based on using these ideas in a clinical setting on individual patients. The work was involved in a High Bone Mass (HBM) study program to identify individuals affected with a genetic condition of LRP5. pQCT data was collected from 169 individuals from the HBM study. 43 people were selected for MRI and MRS acquisition from the total pQCT population. Preliminary results from these investigations have been explained in this abstract. 785. Software Tools for MR and PQCT Bone Quantification Victor Rakesh Lazar1, Gary P. Liney2, David J. Manton1, Peter Gibbs1, Martin Lowry1, Celia L. Gregson3, Joern Rittweger4, Sue Steel5, Chris Langton6, J H. Tobias3, Lindsay W. Turnbull1 1Centre for MR Investigations, University of Hull, Hull, North Humberside, United Kingdom; 2Radiotherapy Physics, University of Hull, Hull, North Humberside, United Kingdom; 3Academic Rheumatology, University of Bristol, Bristol, United Kingdom; 4Excercise and Sports Medicine, Manchester Metropolitan University, Manchester, United Kingdom; 5Centre for Metabolic Bone Disease, Hull Royal Infirmary, Hull, United Kingdom; 6School of Physical and Chemical Sciences, Queensland University of Technology, Australia Peripheral Quantitative Computed Tomography (pQCT) and Dual Energy X-Ray Absorptiometry (DEXA) are the current gold standards for the measurement of bone density and structure, in the research and clinical setting respectively. However, Magnetic Resonance Imaging (MRI) and unsuppressed 1H Magnetic Resonance Spectroscopy (MRS) can also offer several advantages including the ability to quantify bone marrow content and structure. In-house software was developed to process and evaluate cortical and trabecular bone structure, marrow composition and vertebrae segmentation using data from MRI/MRS and structural details from pQCT. 786. Characterization of Bone Explants by Magnetic Resonance Microscopy Ingrid E. Chesnick1, Carol B. Fowler1, Francis A. Avallone2, Kimberlee Potter1 1Department of Biophysics, Armed Forces Institute of Pathology Annex, Rockville, MD, United States; 2Department of Genitourinary Pathology, Armed Forces Institute of Pathology, Washington, DC, United States MRI studies of tissue engineered constructs prior to implantation clearly demonstrate the utility of the MRI technique for monitoring the bone formation process. However, in our studies of osteoblast-seeded scaffolds, implanted on the chorioallantoic membrane of a chick embryo, we have found that the presence of angiogenic vessels and fibrous tissue around the implant can confound MRI findings of bone deposition. On-going studies support the use of targeted contrast agents for studying mineral deposition and blood vessel infiltration in tissue engineered scaffolds post-implantation. Yusuf Abu Tayeb Bhagat1, Chamith S. Rajapakse1, James H. Love1, Michael J. Wald1, Jeremy F. Magland1, Alexander C. Wright1, Hee Kwon Song1, Felix W. Wehrli1 1Laboratory for Structural NMR Imaging, University of Pennsylvania, Philadelphia, PA, United States The detection of subtle microstructural trabecular bone (TB) alterations such as the conversion of plates to rods requires adequate signal-to-noise ratio (SNR), which governs achievable spatial resolution and scan time. Increased SNR may enhance detection sensitivity for microstructural changes in treatment studies. Here, the reproducibility of TB quantitative parameters was investigated using a new 3D fast-spin-echo technique at 7.0T. The imaging and analysis protocol is shown to provide highly reproducible measures of scale, topology and mechanical parameters related to TB microstructure. Performance improvements relative to earlier work are attributed to enhanced SNR, motion control and correction, and improved registration techniques. May Abdel Hamid Taha1, Sarah L. Manske2, Erika Kristensen3, Jaymi T. Taiani4, Roman Krawetz5, Ying Wu, Steven K. Boyd6, John Robert Matyas7, Derrick E. Rancourt5, Jeffery F. Dunn1 1Radiology, University of Calgary, Calgary, Alberta, Canada; 2Kinesiology; 3Mechanical and Manufacturing Engineering; 4 Medical Sciences; 5Departments of Oncology, Biochemistry & Molecular Biology and Medical Genetics; 6Mechanical and Manufacturing Engineering; 7Comparative Biology and Experimental Medicine in Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada The objective of this study was to investigate the effect of different biomaterials on bone healing in vivo in a mouse model of bone injury. These materials; matrigel, purecol gel and hydroxyapatite (HA) are potential matrices to support stem cells. Optimized in vivo MR microscopy and micro computed tomography were used to assess fracture repair. In addition, MRI images and µCT scans were compared at the same time point, to show the difference between them in revealing the actual stage of healing. 789. Traditional Bone Structural Parameters on Different Resolutions in Magnetic Resonance Imaging June-Goo Lee1,2, Gyunggoo Cho1, Youngkyu Song1, Jong Hyo Kim2, Namkug Kim3 1Division of Proteome Research/Bio-Magnetic Resonance Research Center, Korea Basic Science Institute, Cheongwon-Gun, Chungcheongbuk-Do, Korea, Republic of; 2Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul, Korea, Republic of; 3Department of Radiology, Asan Medical Center, University of Ulsan, Seoul, Korea, Republic of Our study focused on the development of robust image processing algorithm on low resolution μ-MR bone image Jenny Folkesson1, Julio Carballido-Gamio1, Dimitrios C. Karampinos1, Patrick Koon2, Suchandrima Banerjee2, Eric Han2, Thomas M. Link1, Sharmila Majumdar1, Roland Krug1 1Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States; 2Applied Science Laboratory, GE Heathcare, Menlo Park, CA, United States With the advent of new MR hardware and pulse sequences it is now possible to image the small trabecular structure of deeper seated regions like the proximal femur with high spatial resolution in a clinically feasible scan time. We employ a novel partial membership bone segmentation technique (BE-FCM) technique that enhances bone segmentation compared to an established dual thresholding method in the presence of signal variations due to different marrow types. We demonstrate that the new image acquisition and analysis framework enables trabecular bone analysis in the deeply situated femoral head, something which has been previously unfeasible in vivo. Dimitrios C. Karampinos1, Huanzhou Yu2, Ann Shimakawa2, Eric T. Han2, Thomas M. Link1, Sharmila Majumdar1, Roland Krug1 1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States There is some evidence that osteoporosis is associated with increased marrow fat content as well as an accelerated conversion from red marrow to yellow (fatty) marrow with age. In this work, we investigated the marrow fat composition in the proximal femur in vivo using IDEAL gradient echo imaging. 3-point IDEAL FGRE hip images of six healthy subjects were acquired and water-fat separation was performed using multi-peak IDEAL. The average fat fraction and standard deviation were determined in three different regions of interest (femoral head, greater trochanter and neck). Significant differences in marrow fat content were identified between the three regions for all subjects. 792. 1H MRS to Detect Biochemical Degenaration of the Vertebral Bone Marrow in Gaucher Disease Simona Ortori1, Michela Tosetti2, Marzio Perri3, Margherita Marchetti1, Gabriele Caproni1, Laura Biagi2, Mirco Cosottini4, Virna Zampa1, Giuliano Mariani3, Carlo Bartolozzi1 1Divisione di Radiologia Diagnostica ed Interventistica, Azienda Ospedaliera Universitaria Pisana, Pisa, Italy; 2MR Laboratory, Stella Maris Scientific Institute, Pisa, Italy; 3Divisione di Medicina Nucleare, Azienda Ospedaliera Universitaria Pisana, Pisa, Italy; 4Dipartimento di Neuroscienze, Universitą di Pisa, Pisa, Italy Gaucher disease is the most prevalent inherited, lysosomial storage disease and results in a deficient level of activity of β-glucocerebrosidase, a membrane-bound lysosomal enzyme. This deficiency leads to accumulation of the lipid glucocerebroside in the lysosomes of monocytes and macrophages, called Gaucher cells. The symptoms and pathology of Gaucher disease result from the accumulation of Gaucher cells in various organ system, including vertebral bodies. To evaluate the biochemical process underlying the infiltration of Gaucher cells, 1H-MRS has been acquired on vertebral bone marrow in patients affected by Gaucher disease, highlighting a significant reduction of fat content of any age range Bailiang Chen1, Bernard Siow2, David Carmichael1,3, Freddy Odille2, Roger Ordidge1, Andrew Todd-Pokropek1 1Medical Physics and Bioengineering, University College London, London, United Kingdom; 2Centre for Medical Image Computing, University College London, London, United Kingdom; 3Institute of Neurology , University College London, London, United Kingdom The recently proposed SPENT sequence can provide direction specific information based on the sub-voxel structural uniformity of a sample. Analogous to diffusion tensor imaging, given a voxel with a local anisotropic structure (e.g. trabecular bone), it is possible to characterize the orientation of sub-pixel micro-structure by applying SPENT with multiple directions. A 6-direction SPENT series was applied to a chicken femur head in order to characterize its trabecular bone orientation by reconstructing a 2D tensor in each voxel. Both tensor statistics and eigensystems were computed and showed good qualitative agreement with data from a subsequent micro-CT acquisitions. 794. The Effect of Freezing on Measurements of Trabecular Bone Structure Based on NMR Spectroscopy Viktoria Prantner1, Hanna Isaksson1, Johanna Närväinen2, Eveliina Lammentausta3, Olli HJ Gröhn2,4, Jukka S. Jurvelin1 1Department of Physics, University of Kuopio, Kuopio, Finland; 2A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, Kuopio, Finland; 3Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; 4Biomedical Imaging Unit, University of Kuopio, Kuopio, Finland NMR is a potential tool for the assessment of trabecular bone structure. Since trabecular bone provides a negligible NMR signal, the indirect evaluation of the trabecular bone structure is based on the analysis of water and fat components in the bone marrow. Earlier studies have revealed that freezing affects the bone marrow structure, suggesting there may be changes in the molecular structure. The aim of the current study is to investigate the effect of freezing on trabecular bone and bone marrow, as assessed by NMR spectroscopy. 795. Performance of Two Spin-Echo Sequences for Quantitative Structure Analysis of Trabecular Bone Michael Jeffrey Wald1, Jeremy Francis Magland1, X. Edward Guo2, Felix Werner Wehrli1 1Laboratory for Structural NMR Imaging, University of Pennsylvania Medical Center, Philadelphia, PA, United States; 2Bone Bioengineering Laboratory, Columbia University, New York, United States The performance of two spin-echo based pulse sequences for imaging trabecular bone microstructure are evaluated at 1.5T in seven fixed, cadaveric distal tibia specimens. SNR efficiency and sensitivity of image-derived trabecular bone structural parameters to variations in bone quality as assessed by µCT were investigated. Inter- pulse sequence correlations suggest similar structural sensitivity, while comparisons to µCT reveal good sensitivity but large deviations in absolute values between modalities. Liya Wang1, Xiaodong Zhong2, Longjiang Zhang3, Diana Tiwari1, Hui Mao1 1Department of Radiology and Emory Center for Systems Imaging, Emory University School of Medicine, Atlanta, GA, United States; 2MR R&D Collaborations, Siemens healthcare, Atlanta, GA, United States; 3Department of Radiology, Jinlin Hospital and Nanjing University College of Clinical Medicine, Nanjing, Jiangsu, China This study provided a quantitative evaluation of skull images obtained using UTE MRI and a direct comparison to those from CT. The skull thickness measured from UTE images showed good agreement with those obtained from CT images in different slices. There is also a good correlation between the thickness measurements obtained from CT and UTE images. Signal intensity based evaluation showed that there is no statistical difference between UTE and CT images in outer, inner layer and diploe of the skull. The comparison of bone UTE MRI and CT of skull suggests that UTE images match closely with CT images. Katrien Vandoorne1, Jeremy Magland2, Vicki Plaks1, Inbal E. Biton3, Amnon Sharir4,5, Elazar Zelzer4, Felix Wehrli6, Brian A. Hemmings7, Alon Harmelin3, Michal Neeman1 1Biological Regulation, Weizmann Institute, Rehovot, Israel; 2Department of Radiology, University of Pennsylvania Health System, Philadelphia, PA, United States; 3Veterinary Resources, Weizmann Institute, Rehovot, Israel; 4Molecular Genetics, Weizmann Institute, Rehovot, Israel; 5The Laboratory of Musculoskeletal Biomechanics and Applied Anatomy, Koret School of Veterinary Medi, Hebrew University of Jerusalem, Rehovot, Israel; 6Department of Radiology, University of Pennsylvania Health System, Philadelphia, PA, Israel; 7Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland Since infiltration of the newly formed blood vessels is required for endochondral bone formation, and PKBalpha/Akt1 mediates intracellular signaling of angiogenesis, we postulated that a vascular deficiency at the site of the long bones could contribute indirectly to impaired bone development in PKBalpha/Akt1 deficient mice. Our study demonstrated using macromolecular DCE-MRI in vivo and ex vivo µCT and µMRI, vascular and bone developmental defects in PKBalpha/Akt1 null mice, and remarkably also in heterozygous mice, lacking a single copy of the gene. Haihui Cao1,2, Jerome L. Ackerman, 2,3, Guangping Dai, 2,3, Mirko Hrovat4, Melvin J. Glimcher, 2,5, Yaotang Wu, 2,5 1Department of Orthopedic Surgery, Children's Hospital , Boston, MA, United States; 2Harvard Medical School, Boston, MA, United States; 3Department of Radiology, Massachusetts General Hospital, Boston, MA, United States; 4Mirtech, Inc, Brockton, MA, United States; 5Department of Orthopedic Surgery, Children's Hospital, Boston, MA, United States Questions have arisen as to the nature of the molecular species giving rise to the short-T2 proton signal in Water- and fat-suppressed proton projection MRI (WASPI), a noninvasive means to image bone. In this study we use deuterium exchange to identify the source of proton signal in WASPI. 799. Quantification of Bound and Mobile Water in Human Cortical Bone by 1H and 2H Magnetic Resonance Henry H. Ong1, Alexander C. Wright1, Felix W. Wehrli1 1Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States Magnetic resonance is a powerful tool for non-destructive study of bone water, which can provide insight into bone micro- and nanostructure. However, the MR signal of bone is comprised of several proton populations including collagen-associated water, and water within the pore space (Haversian and lacuno-canalicular system). We hypothesize that water in pores is predominantly free and water in the bone matrix is predominantly associated with collagen. Using 2H exchange and inversion recovery experiments, we estimated porosity in human cortical bone and found it to agree with micro-CT based volumetric measurements with a significant fraction being collagen-associated. 800. MR Spin Behavior During RF Pulses: T2 Vs. T2' Relaxation Michael Carl1, Nikolaus Szeverenyi2, Mark Bydder2, Eric Han1, Graeme Bydder2 1GE Healthcare, Waukesha, WI, United States; 2University of California, San Diego We investigated the behavior of the MR magnetization vector during RF pulses in the presence of rapid transverse relaxation caused by either amplitude loss or spin dephasing. We found that different tissues with the same T2* may generate different responses to RF pulses, dependent on whether the relaxation is dominated by a homogeneously or inhomogeneously broadened linewidth and RF optimization may hence require explicit knowledge of the intrinsic T2 and T2* of the tissue. Daniel Kuo1, Joseph Schooler1, Janet Goldenstein1, Sarmad Siddiqui1, Swetha Shanbhag1, Jean-Baptiste Pialat1, Andrew Burghardt1, Sharmila Majumdar1, Michael Ries2, Galateia Kazakia1, Xiaojuan Li1 1Musculoskeletal Quantitative Imaging Research (MQIR), Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, United States Osteoarthritis (OA) is a complex disease that affects both cartilage and bone. Bone marrow edema-like lesions (BMEL) are important in studying OA, but knowledge about them is limited. In this study, we take a multi-modality imaging approach, examining MR T1ń and T2 values of BMEL-associated cartilage plus structure and composition of BMEL tissue using high resolution peripheral quantitative computed tomography (HR-pQCT) imaging and Fourier transform infrared (FTIR) spectroscopy. Our results indicate that regions of BMEL are associated with more advanced cartilage degeneration and that there is a localized imbalance in bone formation and mineralization specific to BMEL regions. Jin Zuo1, Sharmila Majumdar1, Xiaojuan Li1 1Radiology and Biomedical Imaging, Univ. of California, San Francisco, San Francisco, CA, United States Anterior cruciate ligament (ACL) tear is a common knee injury, and is a risk factor of post-traumatic osteoarthritis (OA). The disease is frequently associated with bone marrow edema-like (BMEL) lesions which exhibit as an area of high signal intensity in T2-weighted, fat-saturated fast spin echo MR images. BMEL is also commonly seen in OA and has been associated with disease progression and pain in OA. However, the knowledge on the pathophyisiology and significance of BMEL in ACL-injured knees is very limited. Dynamic contrast enhanced MRI (DCE-MRI) can probe bone marrow and subchondral bone perfusion as well as fluid dynamics. Impaired perfusion in bone may lead to cartilage degeneration. A recent study showed bone marrow abnormalities were associated with BME in OA. The aim of this study is to apply DCE MRI to evaluate bone marrow perfusion in patients with ACL tears, and to compare the perfusion patterns between BMEL region and normal appearing bone marrow region. Kai-Yu Ho1, Houchun H. Hu2, Krishna S. Nayak2, Patrick M. Colletti3, Christopher M. Powers1 1Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, United States; 2Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States; 3Department of Radiology, University of Southern California, Los Angeles, CA, United States The purpose of this study was to investigate the influence of running on patellar water content and bone marrow edema (BME) in individuals with and without patellofemoral pain (PFP). Using the IDEAL protocol, two subjects with PFP and 2 pain-free controls were evaluated. Each subject underwent a pre-running MR scan, a 40-min moderate effort running, and a post-running MR scan. Our data showed that in persons with PFP, content and volume of local BME increases post-running. Additionally, the PFP subjects demonstrated increased water content of the bone marrow region post-running while the controls showed no changes in water content. Christine Elizabeth Draper1, Michael Fredericson1, Thor F. Besier1, Gary S. Beaupre2, Scott L. Delp1, Andrew Quon1, Garry E. Gold1 1Stanford University, Stanford, CA, United States; 2VA Palo Alto Health Care System, Palo Alto, CA, United States Articular cartilage deterioration is associated with the development of osteoarthritis. Cartilage health depends upon the integrity of the underlying subchondral bone and there may be abnormalities in bone metabolic activity that accompany structural defects in bone and cartilage. 18F NaF PET/CT enables bone metabolic activity to be visualized. We compared metabolic abnormalities detected using PET/CT with structural defects seen using MRI. We found that regions of increased bone metabolic activity do not always correlate with cartilage damage or bone marrow edema, indicating that 18F NaF PET/CT may image bone abnormalities prior to the development of structural damage seen using MRI. Richard Kijowski1, Catherine Debra Hines2, Huanzhou Yu3, Scott Brian Reeder1,2 1Radiology, University of Wisconsin, Madison, WI, United States; 2Medical Physics, University of Wisconsin, Madison, WI, United States; 3GE Healthcare, Applied Science Laboratory, Menlo Park, CA, United States This study was performed to demonstrate improvements in the quality of fat-suppression for unspoiled GRASS imaging of the knee using multi-peak fat spectral modeling and IDEAL fat-water separation. An IDEAL-GRASS sequence was performed at 3.0T on the knees of 10 asymptomatic volunteers. The IDEAL-GRASS images were reconstructed using a single-peak method and a multi-peak method that more accurately models the NMR spectrum of fat. Multi-peak IDEAL-GRASS had significantly greater (p<0.001) suppression of bone marrow signal and significantly higher (p<0.001) CNR between cartilage and bone marrow than single-peak IDEAL-GRASS. Marine Beaumont1, Marc G. DuVal2, Yasir Loai3, Walid A. Farhat3, George K. Sįndor2, Hai-Ling Margaret Cheng1,4 1The Research Institute and Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Department of Oral and Maxillofacial Surgery, University of Toronto, Toronto, Ontario, Canada; 3Division of Urology, The Hospital for Sick Children, Toronto, Ontario, Canada; 4Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada Tissue repair plays a key role in successful tissue regeneration and involves various simultaneous processes. In bone regeneration, bone growth in a defect occurs only in the absence of early fibrous scar formation or collapse of surrounding tissues into the defect. In this study, a tissue-engineered construct is inserted into a defect in the rabbit calvarium to provide a 3-dimensional resorbable scaffold that maintains a space for bone growth. Multicomponent T2 measurements are performed to characterize and differentiate tissue repair from normal construct resorption. Get a Spine Hall B Tuesday 13:30-15:30 807. High-Resolution MRI at 7 T of Local Strains in the Intervertebral Disc Alexander C. Wright1, Jonathon Yoder2, Nicholas Tustison3, James Gee3, Felix W. Wehrli1, Dawn M. Elliott2 1Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, United States; 3Penn Image Computing and Science Laboratory, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States We have quantified local strains in a bovine tail intervertebral disc by imaging it with a Helmholtz-pair local transmit coil with a decoupled 4-element re-ceive phased array in a whole-body 7 T MRI scanner. The image data were of exceptional quality and were processed by an advanced algorithm to yield high-resolution strain maps in the axial and sagittal planes of the disc. Eito Kozawa1, Waka Mizukoshi1, Naoko Nishi1, Yasuo Sakurai1, Noriko Tanaka1, Fumiko Kimura1 1Saitama Medical University, International Medical Center, Hidaka-shi, Saitama, Japan We illustrate its use for measuring lumbar spine of fat fraction and T2* in normal volunteers and malignant hematological disease patients group with multiple echo gradient echo images (MEGE). Fat fractions of MEGE vs. MR spectroscopy (MRS), and T2* vs. each group were analyzed by linear regression method and Mann-Whitney rank test. Fat fraction values of MEGE and MRS show very good agreement. T2* values vs. each group showed significant difference (p<0.05). In conclusion, MR determination of those parameters could be used to assess and diagnose a deficiency in marrow composition and bone structure using fat fraction and T2*. Yi Xiang Wang1, J F. Griffith1, W L. Kwok2, C S. Leung2, H T. Ma2,3, D K. Yeung1, A T. Ahuja1, P C. Leung2 1Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong; 2Jockey Club Centre for Osteoporosis Care and Control, The Chinese University of Hong Kong, Prince of Wales Hospital; 3Department of Electronic and Information Engineering, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen, China The correlation between osteoporosis and intervertebral disc degeneration in the spine is not fully understood. In this study the relationship between BMD and disc narrowing is analysed in 359 healthy elderly subjects. The results show there was no significant relationship between hip BMD and intervertebral disc space narrowing. With 48 male subjects who had both DXA and QCT, except disc L1/L2, lumbar disc were more likely to have a narrowed space when lumbar BMD was higher. This observed association could be lumbar spine BMD specific since hip BMD better represents systemic BMD. Tsyh-Jyi Hsieh1,2, Twei-Shiun Jaw1,3, Yu-Ting Kuo1,3, Ming-Lun Chiu1, I-Chan Chiang1, Gin-Chang Liu1,3 1Department of Radiology, School of Medicine, College of Medicine, Kaohsiung Medical University, Taiwan, Kaohsiung, Taiwan; 2Department of Medical Imaging, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Taiwan, Kaohsiung, Taiwan; 3Department of Medical Imaging, Kaohsiung Medical University Hospital, Taiwan, Kaohsiung, Taiwan T2-weighted (T2W) iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) ”V fast spin echo (FSE) imaging can provide good uniformity of fat suppression, but the clinical efficiency is not evaluated. The purpose of this work was to evaluate the clinical efficiency of T2W IDEAL FSE imaging of the cervical spine, compared with conventional fat-saturated T2W FSE, including quantitative measurements of SNR and SNR efficiency and qualitative scoring of diagnostic image quality and fat suppression. Jin Zuo1, Xiaojuan Li1, John Kurhanewicz1, Sharmila Majumdar1 1Radiology and Biomedical Imaging, Univ. of California, San Francisco, San Francisco, CA, United States Intervertebral disc degeneration (IVDD) related back pain affects about 80% in the general population during the life-time. Traditional imaging techniques rely on disc morphology while actual disc degeneration begins with internal biochemical and biomechanical changes. Proton magnetic resonance spectroscopy (1H-MRS) is a powerful non-invasive tool that has been used for the assessment of metabolites in tissues. Previously, 1H-MRS on a clinical 3T magnetic resonance (MR) scanner has demonstrated the feasibility of using short-echo water suppressed point-resolved spectroscopy (PRESS) for evaluating biochemical changes in cadaveric bovine and human discs. In these studies the degradation of bovine discs, induced by papain digestion, and the prevalent degeneration in cadaveric discs as assessed with Pfirrmann grading was correlated to spectra measures. In this study, we performed single voxel MRS technique in intervertebral discs from healthy volunteers and T1 and T2 relaxation times of water peak and N-acetyl peak of proteoglycan (PG) in the healthy discs were measured. As dehydration and loss of PG are the two primary consequences of disc degeneration, relaxation times may potentially change with degeneration, and quantification of relaxation times might provide valuable information related to disc degeneration. Rahwa Berhanu Iman1, Serena Hu2, Lynn DeLosSantos1, John Claude3, James Peacock3, Sharmila Majumdar1, John Kurhanewicz1 1Radiology, University of California, San Francisco, San Francisco, CA, United States; 2Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA; 3NociMed, Redwood City, CA The intervertebral disc is thought to be a primary source of low back pain, which is difficult to evaluate clinically. To determine whether chemical biomarkers can discriminate painful from non-painful degenerated discs, ex vivo long echo-time 1H (HR-MAS) spectroscopy data were acquired from intervertebral disc tissue and correlated with a clinical assessment of pain. The relative ratios of the lactate/N-acetyl provide a significant discrimination of painful from non-painful degenerated discs. Although there is a clear need for a larger patient cohort study to validate these findings, the lactate/N-acetyl ratio could provide a potential marker for painful disc degeneration. Articular Cartilage Hall B Wednesday 13:30-15:30 Alexander Watts1, Robert Stobbe1, Adrian Tsang1, Christian Beaulieu1 1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada Sodium MRI of knee cartilage is a possible diagnostic method for osteoarthritis, but low signal strength in vivo results in poor quality images. A steady state approach (shorter TR, longer excitation pulse widths) to 3D twisted projection image acquisition may improve sodium SNR by increased averaging over a constant scan time and SAR of 6 W/kg. Simulations predicted a 42% increase in SNR for steady state over fully relaxed parameters while a 26+/-5% increase was determined experimentally for sodium in human knee cartilage (n=9). Partial volume effects with synovial fluid and/or relaxation parameter differences may be responsible for this disagreement. Goetz Hannes Welsch1,2, Sebastian Apprich1, Tallal Charles Mamisch3, Marius Mayerhoefer1, Stefan Zbyn1, Siegfried Trattnig1 1MR Center, Department of Radiology, Medical University of Vienna, Vienna, Austria; 2Department of Trauma and Orthopaedic Surgery, University Hospital of Erlangen, Erlangen, Germany; 3Department of Orthopaedic Surgery, University of Basel, Basel, Switzerland The aim of the present initial study was to assess T2 and T2* relaxation time values of patella cartilage in healthy volunteers using three different coils (i) eight-channel knee coil; ii) eight-channel multi-purpose coil; iii) surface coil) at 3.0 Tesla MRI. The mean as well as the zonal T2 and T2* values revealed, in most of the cases, significant differences in between the respective coils. These differences were a little less pronounced in the T2* measurements, compared to the T2 evaluations. The present results demonstrate that biochemical T2 and T2* mapping is highly dependent on the utilized coil. 815. dGEMRIC Evaluation 9 to 20 Years After Autologous Chondrocyte Implantation in the Knee Barbro Danielson1, Haris Vasiliadis2, Maria Ljungberg3, Sowmya Vijayakumar4, Nitya Krishnan4, Deborah Burstein4, Lars Peterson5, Brian McKeon6 1Musculoskeletal Section, Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden; 2Molecular Cell Biology and Regenerative Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden; 3Radiation Physics, University of Gothenburg, Gothenburg, Sweden; 4Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 5Orthopedics, Sahlgrenska University Hospital, Sweden; 6New England Baptist Hospital, Boston, United States The study assessed the long-term status of isolated cartilage lesions in the knee after ACT using dGEMRIC. Scans were obtained from 31 patients (5 bilateral lesions) total of 36 lesion sites, representing an f/u period of 9.5 to18.5 years post-implant. The dGEMRIC Index of the implant was greater than 90% of the value of the dGEMRIC Index for surrounding native tissue in 70% of cases, even more than 10 years after the implantation. Sannamari Lepojärvi1, Marianne Haapea1, Tatu Kokkonen2, Juha Isolehto3, Ilkka Kiviranta4,5, Miika T. Nieminen1,6 1Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; 2Department of Radiology, Helsinki University Hospital, Helsinki, Finland; 3Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland; 4Department of Orthopaedics and Traumatology, Helsinki University Hospital, Helsinki, Finland; 5Department of Orthopaedics and Traumatology, Jyväskylä Central Hospital, Jyväskylä, Finland; 6Department of Medical Technology, University of Oulu, Oulu, Finland Joint loading is dependent on the individual loading type. The aim of this study was to investigate the effect of individual, biomechanically determined joint loading type on biochemical properties of load-bearing articular cartilage in the knee joint, as measured by T2 relaxation time mapping and delayed gadolinium enhanced MRI of cartilage (dGEMRIC) in 37 asymptomatic healthy volunteers. The biochemical composition of cartilage is related to the characteristic loading type of individual subjects while the cartilage constituents may vary with physical performance. Cartilage constituents may be altered with exercise and adapt to individual loading conditions in daily-life activities or joint-loading exercise. 817. Comparison of SPGR and Balanced SSFP for Sodium Knee Imaging Ernesto Staroswiecki1,2, Neal Kepler Bangerter3, Garry Evan Gold1, Brian Andrew Hargreaves1 1Radiology, Stanford University, Stanford, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States; 3Electrical and Computer Engineering, Brigham Young University, Provo, UT, United States Early degenerative changes in human articular cartilage are usually accompanied by proteoglycan depletion. Sodium MRI has been shown to correlate with proteoglycan concentration in the tissue. In order to track sodium signal in cartilage, contributions from synovial fluid should be minimized. Here we studied the contrast between fluid and cartilage generated by SPGR and balanced SSFP sequences. We acquired images of phantoms and volunteers at 3T with both sequences and a range of flip angles. Fluid was significantly attenuated on SPGR images with a large flip angle when compared with SSFP data, while the cartilage signal was minimally affected. 818. Age-Related Diffusion Patterns in Intervertebral Disc Degeneration Zhongping Zhang1, Queenie Chan2, Marina Portia Anthony1, Kenneth MC Cheung3, Mina Kim1 1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, China; 2Philips Healthcare, Hong Kong, China; 3Division of Spine Surgery, Department of Orthopaedics and Traumatology, Faculty of Medicine, The University of Hong Kong, Hong Kong, China Intervertebral disc (IVD) degeneration is an age-related condition which is associated with a loss of matrix molecules resulting in an alteration of the biochemical and biomechanical tissue properties. Shedding light on age-related matrix alterations may help improve our understanding of the regulatory mechanisms involved during IVD degeneration. In the present work, we conducted diffusion tensor imaging (DTI) for investigating the diffusion patterns of human IVDs. Our results show that DTI-derived metrics can sensitively assess age-related matrix alterations, which may potentially be a useful biomarker in monitoring degenerative disc disease. 819. Prospective Image Registration for Automated Scan Prescription of Follow-Up Knee Images Janet Goldenstein1,2, Joseph Schooler1, Jason C. Crane1, Eugene Ozhinsky1,2, Julio Carballido-Gamio1, Sharmila Majumdar1 1Department of Radiology and Biomedical Imaging, UC San Francisco, San Francisco, CA, United States; 2Joint Graduate Group in Bioengineering, UC Berkeley/UC San Francisco, San Francisco, CA, United States Consistent scan prescription for MRI of the knee is very important for accurate comparison and quantitative analysis of images in a longitudinal study. This study demonstrates the feasibility of using a mutual information based method to register MR images of the knee without segmentation and automatically determine the follow-up scan prescription. This registration method is performed only on the distal femur and is not affected by the proximal tibia or soft tissues. Results show an improvement with registration in the coefficient of variation for cartilage thickness, cartilage volume, and T2 relaxation measurements. Nitya Krishnan1, Timothy McAlindon2, Melynn Nuite, Kimberly Carr, Deborah Burstein1,3, Lori Lyn Price, Klaus Flechsenhar4 1Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 2Division of Rheumatology, Tufts Medical Center, Boston, MA, United States; 3Health Sciences and Technology , Harvard Medical School, Boston, MA, United States; 4Research & Development, Gelita AG, Eberbach, Germany A pilot study was performed to determine if dGEMRIC or T2-mapping could detect changes in knee cartilage among participants treated with collagen hydrolysate (Fortigel®) versus placebo. A randomized, double-blind, 24-week clinical trial included 30 participants with symptomatic knee OA. Half received 10 grams collagen hydrolysate orally. The dGEMRIC index was able to discriminate between treatment and placebo groups in the tibial regions with an increase in dGEMRIC in the active arm. The sample size was small, and so these data are preliminary. 821. In-Vivo Assessment of Collagen Fiber Arrangement in Articular Cartilage with 7T MRI Nikita Garnov1, Gregor Thörmer1, Wilfried Gründer2, Robert Trampel3, Robert Turner3, Thomas Kahn1, Harald Busse1 1Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany; 2Institute of Medical Physics and Biophysics, Leipzig University, Leipzig, Germany; 3Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany The collagen fiber network determines the biomechanical properties of articular cartilage. It has been shown that the ultrastructure of the cartilage can be assessed by means of T2-weighted high-resolution MRI in vitro. With the recent introduction of ultra-high field whole-body scanners, this approach may also be applied to human in-vivo studies. We describe a method to non-invasively assess the fiber structure of knee cartilage and present first results on three healthy volunteers at 7T. High-resolution in-vivo cartilage MRI is considered a helpful and relatively simple tool to evaluate the integrity of the collagen network and general condition. Tuomas Svärd1, Tomos G. Williams2, Eveliina Lammentausta1, Yang Xia3, Miika T. Nieminen4 1Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; 2School of Cancer, Enabling Science and Technology, The University of Manchester, United Kingdom; 3Department of Physics and Center for Biomedical Research, Oakland University, Rochester, MI, United States; 4Department of Medical Technology, University of Oulu, Oulu, Finland T2 relaxation time in articular cartilage could provide an early biomarker of cartilage quality in disease. T2 measures are dependent on the orientation of collagen fibrils with respect to the B0 field. Variation in joint positioning has a detrimental effect on the reproducibility of T2. In a study of three volunteers, imaged five times each, the variation in orientation of load-bearing femoral joint surfaces was determined using an Active Appearance Model of the distal femur bone. Simulations revealed that the variation in T2 due to joint positioning is acceptable (0.1-4.7ms) compared to the expected elevation related to pathological changes. Tuomas Svärd1, Martti Lakovaara2, Harri Pakarinen2, Ilkka Kiviranta3, Eveliina Lammentausta1, Jukka Jurvelin4, Osmo Tervonen1,5, Risto Ojala1, Miika T. Nieminen1,6 1Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; 2Department of Orthopaedic Surgery, Oulu University Hospital, Oulu, Finland; 3Department of Orthopaedics and Traumatology, Helsinki University Hospital; 4Department of Physics, University of Eastern Finland, Kuopio, Finland; 5Department of Diagnostic Radiology, University of Oulu, Oulu, Finland; 6Department of Medical Technology, University of Oulu, Oulu, Finland The study aimed to determine the usability of biochemical MRI methods, namely T2 relaxation time mapping and dGEMRIC, for detecting early mechanical and visually graded cartilage alterations in vivo, as determined by arthroscopic indentation stiffness measurements and arthroscopic grading, respectively, in 15 subjects. T2 and dGEMRIC values showed a trend with cartilage defect severity, however, no statistical significance was reached. Further, T2 was negatively correlated (r≈-0.6, p<0.05) with cartilage stiffness at several ROIs of the medial compartment. The results suggest that biochemical MRI measurements may be related to information on the mechanical and structural integrity of cartilage. 824. T2 Maps and Diffusion-Weighted Imaging of Knee Cartilage with a DESS Sequence at 3T Ernesto Staroswiecki1,2, Kristin Lee Granlund1,2, Marcus Tedrow Alley1, Garry Evan Gold1, Brian Andrew Hargreaves1 1Radiology, Stanford University, Stanford, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States Detailed visualization of articular cartilage is a challenge that requires advanced MRI techniques. In order to detect early changes of osteoarthritis, we require contrast mechanisms capable of showing biochemical properties of cartilage like T2-mapping and diffusion-weighted-imaging. Here we study the diffusion sensitivity of the T2 maps of cartilage generated with a DESS sequence, and present a method for generating T2-weighted and diffusion-weighted images, together with T2 maps and relative-ADC maps of cartilage via two sequential DESS acquisitions with different gradient amplitudes. 825. Assessment of Subchondral Bone Marrow Lipids in OA Patients at 3T Ligong Wang1, Nouha Salibi2, Gregory Chang, Michael Recht, Ravinder R. Regatte 1NYU Langone Medical Center, New York, NY, United States; 2Siemens Medical Solutions, Malvern, PA, USA This work reported the saturated lipid signals and unsaturated lipid indices in different compartments of femoral-tibial bone marrow in OA patents at 3T. There were significant differences among different compartments of femoral-tibial bone marrow only at 2.03 ppm for saturated lipids (P < 0.002). The tibia has relatively higher saturated lipids compared to the femur. The femur has a relatively higher unsaturated lipid index compared to the tibia. Juhani Multanen1, Eveliina Lammentausta2, Risto Ojala2, Ilkka Kiviranta3, Arja Häkkinen4, Ari Heinonen4, Miika T. Nieminen2,5 1Department of Health Sciences, Jyväskylä University, Jyväskylä, 40014, Finland; 2Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; 3Unit of Orthopaedics and Traumatology, Helsinki University, Helsinki, Finland; 4Department of Health Sciences, Jyväskylä University, Jyväskylä, Finland; 5Department of Medical Technology, University of Oulu, Oulu, Finland The radiological definition of Kellgren/Lawrence (K/L) for classifying osteoarthritis (OA) gives no insight into the status of articular cartilage, the key factor of early pathological changes of OA. The objective of the current study was to determine whether a relationship exists between the K/L grade and the dGEMRIC index of subjects with early OA (K/L grade 1 or 2). The present results show that the dGEMRIC index is significantly shorter in subjects with K/L grade 2 (N=41) as compared to subjects with grade 1 (N=22). The dGEMRIC index was not, however, correlated with the WOMAC pain score. 827. Bound Pool Fractions Correlate with Proteoglycan and Collagen Content in Articular Cartilage Nikola Aleksandar Stikov1, Kathryn E. Keenan2, John Mark Pauly1, R. Lane Smith3, Robert F. Dougherty4, Garry E. Gold, 3,5 1Electrical Engineering, Stanford University, Stanford, CA, United States; 2Mechanical Engineering, Stanford University, Stanford, CA, United States; 3Orthopaedic Surgery, Stanford University, Stanford, CA, United States; 4Psychology, Stanford University, Stanford, CA, United States; 5Radiology, Stanford University, Stanford, CA, United States In this abstract, a novel method for imaging cartilage is proposed. A quantitative magnetization transfer technique called bound pool fraction (BPF) mapping is applied to human ex vivo knee specimens, and correlations with macromolecular content in articular cartilage are presented. BPFs are positively correlated with proteoglycan content, and negatively correlated with collagen content in articular cartilage.
William Wyant Schairer1, Alexander A. Theologis1, Sharmila Majumdar1, Xiaojuan Li1, Benjamin Ma1 1University of California, San Francisco, San Francisco, CA, United States A longitudinal MRI analysis was performed on patients with focal cartilage defects of the femur who received either mosaicplasty or microfracture surgical treatment. We examined T1rho and T2 changes at 3-months and 1-year. Additionally, we performed a laminar analysis to compare the superficial and deep cartilage at the repair site and in the surrounding normal tissue. 829. Effect of Tear of the Medial Meniscus on T2 Relaxation Time of Articular Cartilage Risto Ojala1, Antero Saviluoto1, Ilkka Hannila1, Marianne Haapea1, Osmo Tervonen1,2, Miika T. Nieminen1,3 1Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; 2Department of Diagnostic Radiology, University of Oulu, Oulu, Finland; 3Department of Medical Technology, University of Oulu, Oulu, Finland Meniscal tears are known to increase the risk of osteoarthritis (OA). To assess whether they influence the composition and structure of articular cartilage, T2 relaxation time of medial weight-bearing tibio-femoral cartilage was measured and compared between 20 patients with a tear in medial meniscus and 20 asymptomatic controls. A tear in medial meniscus resulted in significantly longer T2 values in most of the superficial and deep load-bearing medial femoro-tibial cartilage when compared to controls. T2 mapping may provide a sensitive tool to detect early signs of OA. 830. Multi-Component T2* Relaxation of Knee Cartilage Under UTE Acquisitions Yongxain Qian1, Ashley A. Williams2, Constance R. Chu2, Fernando E. Boada1 1MR Research Center, Radiology, University of Pittsburgh, Pittsburgh, PA, United States; 2Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, United States This work presents new observations of T2* decay of multiple components on human knee cartilage explants with ultrashort echo time (UTE) acquisitions on a clinical 3T MRI scanner. Four types of T2* decay (mono-, bi-, tri-, and non-exponential) in cartilage explants were detected. Multi-component T2* decays were mapped on a pixel-by-pixel basis, permitting examination of the spatial distribution of T2* relaxations in cartilage. 831. Regional Relations Within the Medial Meniscus of the Knee Joint - Assessed with DGEMRIC Georg Scheurecker1,2, Marius Mayerhöfer3, Katja Pinker3, Stephan Domayer4, Siegfried Trattnig1,3 1MR Centre of Excellence, Medical University Vienna, Vienna, Austria; 2CT/MRT Institut am Schillerpark, Linz, Upper Austria, Austria; 3Radiology, Medical University Vienna, Vienna, Austria; 4Orthopedic Surgery, Medical University Vienna, Vienna, Austria A standard dGEMRIC protocol for the knee can be used to assess regional relations within the medial meniscus. We found statistically significant different relations of the red with the white zone and of the surface with the core area of the posterior horn between healthy volunteers versus patients after a cartilage repair surgery. This is most probably due to an adaption to different loading patterns of the meniscus in patients after Matrix-associated cartialge transplantation (MACT) versus healthy volunteers. 832. High-Resolution 1H/23Na MR Imaging of Knee Articular Cartilage Using Dual-Tuned Knee Coil at 7T Jung-Hwan Kim1, Chan Hong Moon1, Alessandro Furlan1, Bumwoo Park1, Tiejun Zhao2, Kyongtae Ty Bae1 1University of Pittsburgh, Pittsburgh, PA, United States; 2MR Research Support, Siemens Healthcare, Pittsburgh, PA, United States We acquired high-resolution proton and sodium images at 7T using dual-tuned 1H/23Na coil and 3D ultra-short-echo spiral trajectory sequence and quantitatively analyzed the distribution of sodium signals at different compartments of the knee cartilage. The images demonstrated excellent SNR and resolution of proton and sodium in vivo that allowed us to perform quantitative analysis of the cartilage morphology as well as characterization of cartilage quality. Pottumarthi Prasad1, Wei Li1, Thomas Schnitzer2, Nitya Krishnan3, Deborah Burstein3 1NorthShore University HealthSystem, Evanston, IL, United States; 2Feinberg School of Medicine, Northwestern University, Chicago, IL, United States; 3Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States Treatment of osteoarthritis remains to be symptom modification, although the concept of disease modification is currently evolving. Hylan G-F 20 has been shown to demonstrate disease modifying effects, even though it is currently approved for symptom modification. We have performed preliminary evaluation to see if dGEMRIC can detect changes in patients treated with Hylan G-F 20 in a small number of subjects. While we observed little change, we believe this may be due to the relatively advanced disease status. This is in general agreement with other published human trials using joint space width as an outcome measure. Ping-Huei Tsai1, Hsaio-Wen Chung1, Guo-Shu Huang2 1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; 2Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan Osteoarthritis (OA) is a common disease in aged people, which results in degeneration of the articular cartilage and the meniscus. The purpose of this study is to propose an efficient image segmentation method based on the 2D fussy C-means (FCM) algorithm to facilitate MR T2* measurements, and to investigate the zonal difference of knee cartilages at variable fiber orientations. 835. Comparison of T1ρ, T2 Mapping, and Sodium MRI of Osteoarthritic Cartilage in Vivo Melissa Ann Vogelsong1, Ernesto Staroswiecki2, Brian A. Hargreaves, Eric Han3, Jill A. Fattor4, Anne L. Friedlander5, Omer Shah6, Jacquie M. Beaubien7, Garry E. Gold 1Radiology, Stanford University, Stanford, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA; 3GE Healthcare Global Applied Sciences Laboratory, Menlo Park, CA; 4Stanford Center on Longevity, Stanford, CA; 5VA Palo Alto Healthcare Center, Palo Alto, CA; 6Georgetown University School of Medicine, Washington, DC; 7Psychology, Stanford University, Stanford, CA Several imaging techniques are currently being investigated for use in visualizing cartilage biochemistry. T2 mapping is thought to assess water content and collagen structure while sodium imaging reflects proteoglycan content, however precisely what affects T1ρ relaxation remains unclear. We imaged 9 knees of patients with osteoarthritis and measured T2 and T1ρ relaxation times as well as sodium signal from corresponding ROIs. No correlation was found between T1ρ relaxation and sodium signal, however there was a moderate correlation between T1ρ and T2 relaxation. T1ρ may therefore depend on a complex interaction of macromolecules rather than proteoglycan content alone. 836. Relaxation Along Fictitious Field (RAFF) Contrast in Bovine Articular Cartilage Timo Liimatainen1, Mikko Nissi2,3, Miika T. Nieminen4,5, Shalom Michaeli6, Michael Garwood6, Olli Gröhn7 1Department of Biotechnology and Molecular Medicine, University of Kuopio, Kuopio, Finland; 2Department of Physics, University of Kuopio, Kuopio, Finland; 3Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; 4Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; 5Department of Medical Technology, University of Oulu, Oulu, Finland; 6Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States; 7Department of Neurobiology, University of Kuopio, Kuopio, Finland Possibility of measuring the physicochemical properties of cartilage proteoglycans could help diagnosis and monitoring of osteoarthritis. Relaxation along a fictitious field (RAFF) was optimized to detect proton exchange between water and proteoglycans (OH groups), and its applicability for cartilage imaging was studied using Bloch-McConnell simulations and cartilage samples. Relaxation measurements with optimized RAFF provided better CNRs between deep and intermediate and between deep and superficial cartilage than continuous wave T1ρ corresponding to increasing proteoglycan content towards bone. The RAFF rate constant is suggested as a potential biomarker for cartilage degeneration, also for in vivo imaging. 837. Quantification of Age Dependent Molecular Changes in Guinea Pig OA Model Using T1ρ MRI Matthew Fenty1, Victor Babu Kassey1, George Dodge2, Ari Borthakur1, Ravinder Reddy1 1Center for Magnetic Resonance and Optical Imaging, University of Pennsylvania School of Medicine, Philadelphia, PA, United States; 2Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, United States T1ρ MRI is sensitive to molecular changes in cartilage, which have been shown to occur early in osteoarthritis. Dunkin-Hartley guinea pigs spontaneously develop osteoarthritis within 9 months of age. This study quantifies the age dependent degeneration of cartilage in the guinea pig stifle using T1ρ MRI with detailed correlation using histology and immunohistochemistry. Ping-Huei Tsai1, Ming-Chung Chou2, Ming-Huang Lin3, Chien-Yuan Lin3, Hsaio-Wen Chung1, Herng-Sheng Lee4, Guo-Shu Huang2 1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; 2Department of Radiology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; 3Institute of Biomedical Sciences, Academic Sinica, Taipei, Taiwan; 4Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan Osteoarthritis (OA) is a disease related to the degeneration of cartilage, pathological change of subchondral bone (SB) and so force, which may leads to a series of inflammation and pain responses. The purpose of this study is to investigate the relationships among cartilage, menisci and SB with the progression of OA by MR T2* measurements. Yi Xiang Wang1, M Deng1, H T. Ma2,3, Y F. Zhang4, J F. Griffith1, T C. Kwok4, A T. Ahuja1 1Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong; 2Jockey Club Centre for Osteoporosis Care and Control, The Chinese University of Hong Kong, Prince of Wales Hospital; 3Department of Electronic and Information Engineering, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen, China; 4Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital Clinical studies have shown femoral head has a poorer blood supply compared to femoral neck and femoral shaft. It has been suggested that delayed wash-out in DCE MRI suggests tissue blood stasis or outflow obstruction. In this study, the DCE MRI wash-out characteristics in femoral head of normal rats were investigated, and comparison was made to those of proximal and distal femoral diaphysis, distal femoral epiphysis, proximal tibial epiphysis, proximal tibial diaphysis. After the initial fast wash-in phase, for femoral head a continuous further slow wash-in was observed, while other sites showed a wash-in phase followed by a wash-out phase. 840. Z-Spectroscopy with Phase Alternating Irradiation (ZAPI) in Articular Cartilage Mikko Johannes Nissi1,2, Miika Tapio Nieminen3,4, Olli Heikki Gröhn5, Johanna Närväinen5 1Department of Physics, University of Kuopio, Kuopio, Finland; 2Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; 3Department of Medical Technology, University of Oulu, Oulu, Finland; 4Department of Diagnostic Radiology, Oulu University Hospital , Oulu, Finland; 5Department of Neurobiology, A.I. Virtanen Institute for molecular Medicine, University of Kuopio, Kuopio, Finland Exchange between collagen and bulk water in cartilage has been observed earlier in Magnetization transfer (MT) experiments. In the present study, the suitability of a recently introduced MT method, alternating phase irradiation Z-spectroscopy (ZAPI), in characterization of MT and T2 distribution in bovine cartilage was investigated. Use of alternating phase (AP) irradiation in ZAPI provides a unique possibility for T2 filtering by adjusting the pulse parameters. ZAPI was used for Z-spectroscopy and T2 filtered on-resonance MT of cartilage samples and the dependence of these parameters as a function of cartilage depth was analyzed. 841. Measurement of T1 Relaxation Time in Articular Cartilage Using SWIFT Mikko Johannes Nissi1,2, Lauri Juhani Lehto3, Curtis Andrew Corum4, Djaudat Idiyatullin4, Olli Heikki Gröhn5, Miika Tapio Nieminen6,7 1Department of Physics, University of Kuopio, Kuopio, Finland; 2Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; 3Department of Biotechnology and Molecular Medicine, University of Kuopio, Kuopio, Finland; 4CMRR, University of Minnesota, Minneapolis, MN, United States; 5Department of Neurobiology, A.I. Virtanen Institute for molecular Medicine, University of Kuopio, Kuopio, Finland; 6Department of Medical Technology, University of Oulu, Oulu, Finland; 7Department of Diagnostic Radiology, Oulu University Hospital , Oulu, Finland Spins with sub-millisecond T2 relaxation times are virtually invisible in conventional MRI. Signal from articular cartilage is typically low due to effective dipolar coupling. In this study, T1 maps of articular cartilage were measured using the recently introduced SWIFT method, which is capable of acquiring signal from virtually all spins, with a T2 sensitivity limit around few microseconds. The feasibility and performance of SWIFT for T1 measurements was compared to conventional FSE method. SWIFT had better SNR performance especially in cartilage layers with short T2. The T1 values measured using SWIFT were comparable to those measured with FSE sequence. 842. Multiexponential T2 Relaxation Analysis to Assess the Development of Engineered Cartilage Onyi Irrechukwu1, Remy Roque1, David Reiter1, Richard Spencer1 1National Instiute on Aging, National Institutes of Health, Baltimore, MD, United States The objective of this study was to use multiexponential analysis of T2 relaxation data to monitor the development of engineered cartilage. Chondrocyte-seeded collagen constructs were studied after 1-4 weeks of culture. Four water compartments were consistently detected; however, an additional compartment, T21-2, emerged in week 4. The two most slowly relaxing components, T23 and T24, loosely associated with macromolecules, decreased with macromolecular synthesis. T22 was assigned to PG monomers and the appearance of T21-2 was consistent with aggregation of these monomers. T21 was assigned to collagen-bound water and its fraction size decreased in week 4, an indication of scaffold degradation. José G. Raya1, Lucianna Filidoro1, Andreas Kellerer2, Olaf Dietrich1, Elisabet Mützel3, Maximilian F. Reiser2, Peter Jakob4, Christian Glaser2 1Josef Lissner Laboratory for Biomedial Imaging, Departmentof Radiology, University of Munich, Munich, Germany; 2Department of Clinical Radiology, University of Munich; 3Department of legal medicine, University of Munich, Germany; 4Departmentof experimental physics 5, University ofWuerzburg, Germany DTI of the articular cartilage has been restricted to ultra-high fields (>7T) and small samples because of the short T2 and high resolution needed. The aim of this work was to demonstrate the value of DTI of the cartilage performed ex vivo on a 1.5T scanner and to characterize the patterns of pathology. Excised human patellar cartilage (n=25) has been examined at 1.5T. Additionally, six samples have been imaged at 17.6T. DTI parameters were very similar at both field strengths. Imaging the whole cartilage plate allowed identifying different patterns of pathology: focal lesions, alterations of the subchondral bone and osteophytes. David A. Reiter1, Remy A. Roque1, Ping-Chang Lin1, Onyi Irrechukwu1, Nancy Pleshko2, Richard G. Spencer1 1National Institute on Aging, National Institutes of Health, Baltimore, MD, United States; 2Department of Mechanical Engineering, Temple University, Philadelphia, PA, United States We sought to improve the specificity of cartilage matrix assessment through localized multiexponential T2 analysis permitting the mapping of matrix associated water compartments. Maps of MR-derived proteoglycan- (PG) bound water fractions (wPG) showed differences between young and mature cartilage; these differences were consistent with biochemically-derived PG content and Fourier-transform infrared spectroscopic imaging (FT-IRIS) derived PG content. Good spatial correspondence was observed between wPG maps and FT-IRIS-derived PG maps normalized by water content, demonstrating the potential of this approach to detect and map PG in degraded cartilage. 845. The Macromolecular 1H NMR Lineshape in Cartilage Gil Navon1, Uzi Eliav1 1School of Chemistry, Tel Aviv University, Tel Aviv, Israel The analysis of the magnetization transfer contrast under incomplete saturation of the macromolecules (common in clinical setups) requires the knowledge of the macromolecular spectral lineshape. In previous studies this information was retrieved by fitting the MTC data to models where the lineshape characteristic was kept as a free parameter. In the current study we present a method that is a combination of double and zero quantum filtering for measuring the macromolecular lineshape. A demonstration of the method is given for the macromolecular fraction of articular cartilage. The lineshape is Gaussian with width at half height of 27.3 kHz. 846. High-Resolution DTI to Study Articular Cartilage Dehydration Cesare E. M. Gruber1,2, Silvia Capuani, 12, Giovanni Giulietti3, Tommaso Gili, 1,3, Bruno Maraviglia1,4 1Physics, SAPIENZA University of Rome, Rome, Italy; 2Physics, CNR-INFN SOFT, Rome, Italy; 3MARBILab, Enrico Fermi Center, Rome, Italy; 4Neuroimaging Laboratory, IRCCS Santa Lucia Foundation, Rome, Italy T2-w scans and DTI were used to monitor degradation processes in cartilage samples due to dehydration. T2-w measures did not provide useful information. Conversely, DTI revealed a decrease of MD and an increase of FA over the first 48hrs, thus suggesting a reduction of water content and a consequent increase of collagen fibril density. More interestingly, increased MD and decreased FA were observed between 48 and 60hrs. This finding likely reflects degeneration of proteoglycans. These experimental observations propose a new model to investigate the pathophysiology of osteoarthritis, and might prompt a new MRI approach for diagnostic purposes in humans. Claudia Fellner1, Ernst M. Jung1, Stefan Feuerbach1, Lukas Prantl2 1Institute of Radiology, University Medical Center Regensburg, Regensburg, Germany; 2Department of Traum and Plastic Surgery, University Medical Center Regensburg, Regensburg, Germany The aim of this study was to evaluate the perfusion of free flaps using DCE MRI. DCE covering the whole flap was performed in 11 patients. Signal increase over time in normally perfused flaps was similar to the reference tissue; there was no significant difference depending on the position within the flap. In flaps with compromised perfusion the increase was significantly lower than in the reference tissue. Normalized signal increase in adequately perfused flaps and flaps with compromised perfusion showed a significant difference. DCE MRI may be a valuable non-invasive tool to evaluate tissue perfusion of the complete free flap.
Karl G. Baum1, Edward Schreyer1, Saara Totterman1, Joshua Farber1, Jose Tamez-Peńa1, Patricia Gonzįlez1 14Qimaging, LLC, Rochester, NY, United States Quantitative analysis of MRI images is providing new insight into and sensitivity to detect osteoarthritic progression, but is encumbered with the time, cost and variability associated with manual or semi-automated segmentation. To address this, a fully-automated knee MRI segmentation and analysis method was developed and validated. Although the method has proven to be robust, in a small percentage of cases (< 2%) underlying image quality or other anomalies may produce poor segmentation results. This study examines the feasibility of using the Dice Similarity Coefficient (DSC) as an objective, reproducible and automated method of accurately detecting segmentation failure. 849. High Resolution Bilateral Hip Joint Imaging at 7 Tesla Using Fast Multi-ROI B1 Shim Methods Jutta Ellermann1,2, Ute Goerke2, Pierre-Francois Van de Moortele2 1University of Minnesota Medical School, Minneapolis, MN, United States; 2Center for Magnetic Resonance Research, Minneapolis, MN, United States Recent advances in orthopedic surgery allow for successful treatment of subtle developmental, often bilaterally occurring hip joint abnormalities. Femoroacetabular impingement (FAI) typically causes labral tears and chondral lesions. Clinical unilateral studies at 1.5 and 3T often use intraarticular Gadolinium. In this preliminary study, we demonstrate that high resolution, high contrast/noise images can be obtained at 7 T without contrast enhancement, both hips being imaged simultaneously despite of transmit B1 distortion at very high field. Key components include the use of a transceiver RF coil array together with fast, low SAR B1+ shim methods, which could become standard components in 7T imaging protocols.
You Have Fat Muscle Hall B Thursday 13:30-15:30 850. Three and Four Point Dixon Comparison at 3T: in Vitro and in Vivo Nathan Noble1,2, Stephen Keevil1,3, John Totman4, Geoff Charles-Edwards1,3 1King's College London, London, United Kingdom; 2King's College Hospital, London, United Kingdom; 3Guy's and St Thomas' Hospital, London; 4Imaging Sciences, King's College London In this study, 3 and 4-point Dixon MRI methods were compared at 3T in phantoms with known compositions of fat and water and compared to fat-water ratios from localised MRS in the calf muscle from eight healthy volunteers.In vitro, both 3 and 4 point Dixon techniques investigated correlated well with the fat content of the phantoms. In vivo, the 4 point Dixon technique with a 1 or 1.22 ms ÄTE appears to be the more reliable technique for intra muscular fat quantification. Beatrijs Henriette Aleid Wokke1, Clemens Bos2, Holger Eggers2, Andrew G. Webb3, Hermien E. Kan3 1Neurology, Leiden University Medical Centre, Leiden, Netherlands; 2Philips Healthcare, Best, Netherlands; 3Radiology, Leiden University Medical Centre, Leiden, Netherlands MRI is finding increasing importance in the follow up of muscle diseases in which there is fatty muscle infiltration. Techniques such as multiecho chemical shift-based water-fat separation are highly useful because they provide quantitative values for fat fractions. Despite the presence of multiple peaks in the fat spectrum, the fat fraction is usually obtained through a single peak model. Multipeak correction should improve the obtained fat fraction. In this study we validate that correction for multiple fat peaks does indeed improve quantification of fat fractions in vitro and is applicable to, and highly reproducible in, muscle studies in vivo. Chris David James Sinclair1,2, Jasper M. Morrow1, Tarek A. Yousry1,2, Xavier Golay2, John S. Thornton1,2 1MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London WC1N 3BG, United Kingdom; 2National Hospital for Neurology and Neurosurgery, London WC1N 3BG, United Kingdom We performed a test-retest reproducibility study of histogram metrics in the thigh and calf muscles of 8 healthy individuals. Quantitative maps of MT ratio, T2 relaxation time and 3-point Dixon fat-fraction were acquired from each subject twice with a between scan interval of 14 days. The inter-scan reproducibility of the fitted histogram peak position was evaluated using intra-class correlation coefficients and Bland-Altman plots. No systematic differences were noted and most variability could be attributed to differences between individuals, providing confidence that similar implementation of these methods may be used as potential markers of neuromuscular disease in patient groups. Kieren Grant Hollingsworth1, Tracey A. Willis2, Anna Coombs3, Anna Mayhew2, Michelle Eagle2, Andrew Mark Blamire1, Volker Straub2 1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; 2Institute of Human Genetics, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; 3SFC Brain Imaging Research Centre, Edinburgh University, Edinburgh, United Kingdom LGMD2I leads to muscle wasting, necrosis, and fat infiltration. Future trials of therapy require robust measures of fat infiltration and infiltration pattern to determine whether muscle deterioration can be arrested. T1w imaging and 3-point Dixon was performed at calf and thigh for 13 diagnosed LGMD2I patients and 6 age-matched controls. A 6-point scale assessment and region-of-interest quantitative analysis of calf and thigh muscles in one cross-section were performed. Generally, thigh muscles were more fat infiltrated than the calf muscles. Qualitative and quantitative measures were significantly correlated, though there was considerable overlap of fat percentages at the lower qualitative grades. Heiko G. Niessen1, Michael Neumaier1, Thomas Kaulisch1, Corinna Schoelch2, Detlef Stiller1 1In-Vivo Imaging Unit, Dept. of Drug Discovery Support, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany; 2Dept. of Cardiometabolic Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany Intramyocellular lipids (IMCL) have been identified as important marker for insulin resistance in type 2 diabetes. We used in vivo MRS to evaluate the efficacy of a CB1-receptor antagonist on the muscle lipid content. MR measurements were performed using a custom-made Helmholtz coil set-up for signal reception. After a significant reduction of IMCL content upon treatment, reservoirs almost completely recover within two weeks after treatment. In addition to significant differences between control and treated rats, different time points can be distinguished by their IMCL content. IMCL data correlate with body fat content, body weight and other biochemical parameters. 855. Optimization of Spectroscopy-Based Diffusion Measurements of Intramyocellular Lipids Vaclav Brandejsky1, Roland Kreis1, Chris Boesch1 1Department of Clinical Research, University of Bern, Bern, Switzerland Intramyocellular lipids (IMCL) are related to insulin resistance and are an important substrate for the muscular metabolism. Studies of diffusion properties of these lipids in vivo may contribute to the understanding of their physiological role. However, due to low diffusion coefficients, very strong gradients are required leading to motion artifacts. Cardiac pulsations induce additional signal variations. This study aimed at optimizing parameters for diffusion measurements by MR spectroscopy in skeletal muscle. It was found that both physiologic triggering and independent phase corrections of individual spectra is essential to obtain correct diffusion measurements for IMCL in vivo. Thomas WJ Ash1, Guy B. Williams1, Fiona Regan2, Sally Georgia Harding1, Tero Saukkonen2, David B. Dunger2, T Adrian Carpenter1, Alison Sleigh1 1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom; 2Department of Paediatrics, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom Using machine learning (support vector machines) we construct a model that classifies soleus muscle spectra of adolescents into Type 1 diabetes / control groups with 95% accuracy in leave one out tests. This is an improvement on previous analysis of the data using solely IMCL peak area calculations which achieves 84% accuracy. The model confirms that IMCL height increases in type one diabetics, as well as showing that creatine and choline peaks are broadened in the type 1 diabetic group. Francisco Ortiz-Nieto1, Jan Weis1, Lars Johansson1,2, Håkan Ahlström1 1Department of Radiology, University Hospital, Uppsala, Sweden; 2Astra Zeneca R&D The purpose of this study was to determine and compare EMCL and IMCL content in the calf and thigh muscles of normal male and female volunteers using high spatial resolution MRSI. A common feature for both genders was higher total fat content in the thigh muscles compared with the calf. The mean IMCL level was, however, higher in the calf muscles. No significant differences in lipid concentrations of correspondent VOIs were found between genders. The high-spatial-resolution MRSI technique enables a more detailed study of muscle lipid distribution. Muscle: Energetics & Exercise Hall B Monday 14:00-16:00 858. Creatine Methylene Group and PCr Observed by Interleaved 1H/31P MRS During Muscle Exercise Martin Meyerspeer1,2, Roberta Kriegl3, Ewald Moser1,4 1Biomedical Technology and Physics, Vienna Medical University, Vienna, Austria; 2High Field MR Centre of Excellence, Vienna Medical University, Austria; 3Siemens Austria; 4High Field MR Centre of Excellence, Vienna Medical University, Vienna, Austria Data were measured with interleaved dynamic localised 1H and 31P spectroscopy, following PCr and Cr2 signal during ischaemic rest, exercise and recovery of human calf muscle.
859. Post-Ischemic Stenosis and Reperfusion Studied by Dynamic 31P MRS and Functional Imaging Albrecht Ingo Schmid1,2, Martin Andreas3, Martin Meyerspeer2,4, Ewald Moser1,4, Michael Wolzt1 1Dpt. of Clinical Pharmacology, Medical University of Vienna, Wien, Austria; 2MR Center of Excellence, Medical University of Vienna, Wien, Austria; 3Department of Cardiac Surgery, Medical University of Vienna, Wien, Austria; 4Center of Biomedical Engineering and Physics, Medical University of Vienna, Wien, Austria Post-ischemic stenosis is a common clinical finding, yet rarely studied by NMR. 31P MRS and BOLD sensitive EPI was measured (two days) in 11 male subjects, with and without 5min stenosis (cuff at 30mmHg below cystolic pressure) following 20min cuff (thigh), the last two minutes performing plantar flexion. During stenosis pH and PCr remained at post-ischemic levels, BOLD signal declined further. In conclusion, stenosis is a state in which oxygen supply is insufficient to start PCr recovery. Gwenael Layec1, Emil Malucelli2, Christophe Vilmen1, David Manners2, Kazuya Yashiro1, Claudia Testa2, Patrick J. Cozzone1, stefano Iotti2, David Bendahan1 1CRMBM UMR CNRS 6612, Marseille, France; 2Dipartimento di Medicina Interna, dellInvecchiamento e Malattie Nefrologiche; Universitą di Bologna, Italy It is acknowledged that mitochondrial function can be assessed in vivo from PCr resynthesis during recovery period. Several studies have pointed out that end-of-exercise conditions could bias the characterization of mitochondrial function. The purpose of the present study was to analyze the relationship between end-of-exercise pH and PCr recovery rates in forearm, calf and thigh muscles in a single group of subjects in order to determine whether a common normalisation frame could be adopted for different muscles. Overall, our results clearly illustrate that, whatever the muscle investigated, low end-of exercise pH is systematically related to a slower PCr recovery kinetics. Marco Jauslin1, Anke Henning1, Ulrike Dydak2, Haiko Sprott3, Dieter Meier1, Hans H. Jung4, Peter S. Sįndor4, Peter Boesiger1 1Institute for Biomedical Engineering, ETH and University Zürich, Zürich, Switzerland; 2School of Health Sciences, Purdue University, West Lafayette, IN, United States; 3Department of Rheumatology and Institute of Physical Medicine, University Hospital Zürich, Zürich, Switzerland; 4Department of Neurology, University Hospital Zürich, Zürich, Switzerland Differences in phosphocreatine recovery (represented by its time constant, normalized for pHmin) between controls and patients with mitochondrial encephalomyopathies (and migraine with aura) have been detected with 31P-MRS exercise protocols of both low and increasing intensity at low contraction frequency. By employing a protocol of high intensity and high contraction frequency these differences vanish, which may be explained by higher fractions of activated fast twitch fibers and interindividual variations in muscle fiber type composition in controls. Our observations therefore challenge the notion of absolute workload independence of PCr recovery due to different recovery characteristics of fast and slow twitch fibers. 862. Localised Versus Unlocalised Dynamic 31P MRS Acquisition in Exercising Human Muscle at 7T Martin Meyerspeer1,2, Ewald Unger1, Thomas Mandl1,2, Tom Scheenen3, Graham J. Kemp4, Ewald Moser, 2 1Center for Biomedical Technology and Physics, Vienna Medical University, Vienna, Austria; 2High Field MR Centre of Excellence, Vienna Medical University, Vienna, Austria; 3Dpt. of Radiology, Radboud University, Nijmegen, Netherlands; 4School of Clinical Science, Faculty of Medicine, University of Liverpool, Liverpool, United Kingdom The effect of localised versus non-localised 31P MRS on data acquired from aerobically exercising human gastrocnemius muscle is studied at ultra hight field. For localisation, a short TE single voxel spectroscopy MR sequence comprising adiabatic refocussing which allows high temporal resolution is used. From a series of exercise bouts of equal intensity we conclude that with localisation, PCr is depleted to a lower level, recovery from depletion is faster and no compartmentation of pH, manifest in a spliting of the Pi peak is observed, in contrast to non-localised 31P MRS. Douglas E. Befroy1, Ryan G. Larsen2, Michael A. Tevald2, Jane A. Kent-Braun2 1Yale University, New Haven, CT, United States; 2University of Massachusetts, Amherst, MA, United States Several MRS methods have been developed to investigate muscle mitochondrial function in-vivo. Although some studies have detected alterations in oxidative metabolism in the elderly and type-2 diabetes, others have discerned no effect. Resolving these disparities is confounded by differences in subject selection and muscle metabolic phenotype between studies, and by methodological differences between techniques. To establish whether correlated or independent parameters of mitochondrial metabolism are assessed by these methods, we have directly compared three 31P-MRS techniques: resting Pi → ATP flux, ischemic PCr decline and post-contraction PCr recovery, in a single muscle compartment in a group of healthy male subjects. 864. Exercise Ability Is Determined by Muscle ATP Buffer Content, Not Pi or PH Jeroen A.L. Jeneson1, Joep P. Schmitz1, Johannes H. van Dijk2, Dick F. Stegeman2, Peter A. Hilbers1, Klaas Nicolay1 1Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 2Clinical Neurophysiology, University Medical Center St Radboud, Nijmegen, Netherlands Muscle fatigue is a primary symptom in human myopathy. Its molecular basis remains hotly debated. We tested the in vivo significance of two leading hypotheses i.e., Pi accumulation and muscle acidification using bicycle ergometry, 31P MR spectroscopy and multi-channel surface electromyography. The experimental design allowed quasi-independent manipulation of intramuscular concentrations of Pi and H+ at the start of exercise. It was found that the ability of a subject to exercise against a supramaximal load maintaining a pedaling frequency of 80 rpm was neither affected by low intramuscular pH or high Pi but required a minimal phosphocreatine concentration of 5 mM. Noriyuki Tawara1, Osamu Nitta2, Hironobu Kuruma2, Mamoru Niitsu3, Atsuto Hoshikawa1, Toru Okuwaki1, Akiyoshi Itoh4 1Department of Sports Medicine, Japan Institute of Sports Sciences, Tokyo, Japan; 2Department of Physical Therapy, Tokyo Metropolitan University, Tokyo, Japan; 3Department of Radiological Sciences, Tokyo Metropolitan University, Tokyo, Japan; 4NIHON University, Chiba, Japan Exercise-induced muscle activity is essential in sports medicine, especially for the trunk muscle. MRI can evaluate muscle activity; T2 of exercised muscle increases compared to that of rested muscle. Previous studies have proposed the muscle functional MRI (mfMRI), which visualizes muscle activity in enhanced activated muscle. However, the body parts that can be studied by mfMRI are limited to the limbs. In order to evaluate trunk muscle activity induced by exercise, we proposed and verified the feasibility of mfMRI using ultrafast imaging. This study evaluated the detectability of the slight impact on trunk muscle activity induced by acute exercises. 866. Detection of the Temporal Sequence of Muscle Recruitment During Cycling Exercise Using MRI Christopher Paul Elder1,2, Ryan N. Cook1,3, Ken L. Wilkens1, Marti A. Chance2, Otto A. Sanchez, 12, Bruce M. Damon, 12 1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 2Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; 3Biomedical Engineering, Vanderbilt University, Nashville, TN, United States The purpose of this project was to use MRI to determine the temporal sequence of muscle recruitment during cycling by applying variable work rates during the pedal cycle and validate the imaging data using electromyography. Variable work rates were applied in two different distributions; the first increased post-exercise T2 in the extensors and flexors of the thigh, the second increased post-exercise T2 in the flexors only. Similar patterns were observed in the electromyography data, providing validation for the future use of the technique to fully characterize recruitment in individual muscles during cycling, along with applications to functional electrical cycling. Theodore F. Towse1, Jill M. Slade2, Michael T. Andary3, Ronald A. Meyer1 1Physiology, Michigan State University, East Lansing, MI, United States; 2Radiology, Michigan State University, East Lansing, MI, United States; 3Physical Medicine And Rehabilitation, Michigan State University, East Lansing, MI, United States Loss of motor units is often compensated for by reinnervation of fibers from nearby axons, leading to unit reorganization and fiber-type clumping. Previous studies suggest that motor unit reorganization could result in increased heterogeneity of the T2 increase observed by MRI after moderate exercise. This study shows that, despite a 50% decrease in motor unit number in anterior tibial muscles of elderly vs. younger subjects, the heterogeneity of muscle T2 after exercise is no greater in elderly than in younger subjects. The results suggest that fiber reinnervation is not a dominant mechanism compensating for motor unit loss in muscles of elderly subjects. Rajat Gupta1, Uma Sharma2, Nandita Gupta1, U Singh3, Randeep Guleria4, Naranamangalam R. Jagannathan2, Ravinder Goswami1 1Department of Endocrinology, All India Institute of Medical Sciences, New Delhi, Delhi, India; 2Department of NMR & MRI Facility, All India Institute of Medical Sciences, New Delhi, Delhi, India; 35Department of Physical Medicine and Rehabilitation, All India Institute of Medical Sciences, New Delhi, Delhi, India; 4Department of Medicine, All India Institute of Medical Sciences, New Delhi, Delhi, India Effects of six months cholecalciferol and calcium supplementation was investigated on the skeletal muscle strength and muscle energy metabolism using 31PMRS in healthy volunteers with low serum 25(OH)D in a double blind randomized placebo controlled trial. At six months, 25(OH)D levels, hand grip strength, gastrosoleus muscle strength, distance covered during six minute walk were significantly higher in cholecalciferol compared to placebo group (p=0.001). There were no significant differences in MIP, MEP and PCr/Pi ratio in the two groups at six months. Thus, improvement in muscle strength could be due to factors other than change in muscle energy metabolism. Muscle: Everything Else Hall B Tuesday 13:30-15:30 869. Short TR, Elongated Echo Time Spectroscopy (STREETS) of Muscle at 3 T. Giulio Gambarota1, Mark Tanner1, Rex D. Newbould1 1GlaxoSmithKline Clinical Imaging Center, London, United Kingdom The measurement of IMCL is hampered by the fact that IMCL resonances overlap with the much larger resonances of extramyocellular lipids (EMCL). Long echo time acquisition allows for a better discrimination of IMCL from EMCL, however, it to suffer from the low signal-to-noise ratio (SNR). In the current study, we show that with a the short TR of 600ms, a 50% improvement in SNR (compared to TR = 2s) is achieved in lipid spectra. 870. Sodium Concentration Quantification in Human Calf Muscle Using UTE Imaging at 7.0T Peter Linz1, Davide Santoro2, Wolfgang Renz, 2,3, Friedrich C. Luft4, Jens Titze1, Thoralf Niendorf2,4 1Department of Nephrology and Hypertension, University Clinic Erlangen-Nuernberg, Erlangen, Germany; 2Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany; 3Siemens Medical Solutions, Erlangen, Germany; 4Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany Sodium metabolism in muscle is changed in hypertensive animal models. With Na high field MRI and UTE-sequences Na-concentrations in human muscle can be studied at fast acquisition times. times. 871. Quantitative Magnetization Transfer in In Vivo Healthy Human Skeletal Muscle at 3T Chris David James Sinclair1,2, Rebecca S. Samson3, David L. Thomas4, Nikolaus Weiskopf5, Antoine Lutti5, John S. Thornton1,6, Xavier Golay, 2,6 1MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London WC1N 3BG, United Kingdom; 2Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London WC1N 3BG, United Kingdom; 3Department of Neuroinflammation, UCL Institute of Neurology, London WC1N 3BG, United Kingdom; 4Advanced MRI Group, UCL Medical Physics, London WC1N 3BG, United Kingdom; 5Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London WC1N 3BG, United Kingdom; 6National Hospital for Neurology and Neurosurgery, London WC1N 3BG, United Kingdom We applied a quantitative magnetization transfer model to healthy human muscle data in vivo to pave the way to its implementation in patients with neuromuscular diseases. The right lower leg of 10 subjects was imaged at 3T with an MT-prepared sequence with variable offset frequencies and amplitudes and accompanying T1 and B1 maps. A 2-pool MT model accounting for pulsed saturation was fitted to the data to obtain qMT parameters for normal muscle such as T2 of the restricted proton pool and the restricted pool fraction f, measured to be around 8%. Donghoon Lee1, Martin Kushmerick1, Zejing Wang2, Stephen Tapscott2 1University of Washington, Seattle, WA, United States; 2Fred Hutchinson Cancer Research Center, Seattle, WA, United States One challenge of gene therapy, a promising treatment for Duchenne muscular dystrophy, is to understand immune responses to adeno associated virus (AAV) vectors used for gene delivery. Canine MR imaging was conducted to noninvasively monitor local inflammatory responses to AAV in dog muscle over time by measuring T2 values and volumes of the inflammatory areas. The volume increase of 33 ~ 150 % was monitored on semitendinosus muscle and the median T2 value was significantly higher at the sites of AAV injection (60.1 ± 5.4 ms) than those from the un-injected muscles (33.6 ± 0.5 ms) in the contra-lateral muscle. Keerthi Shet1, Sarmad Siddiqui2, John Kurhanewicz2, Xiaojuan Li1 1Radiology, University of California at San Francisco, San Francisco, CA, United States; 2Radiology, University of California at San Francisco, San Francisco , CA, United States Osteoarthritis (OA) is a degenerative joint disease that results in degradation and gradual loss of articular cartilage. Proteoglycan loss and alteration in the cartilage has been considered an important marker for detecting and measuring the progress of OA. The N-acetyl resonance observed in HR-MAS spectra arises from the proteoglycan content in cartilage. We aim to detect the changes in the mobility of the N-acetyl moiety due to the degradation process that occurs in OA as reflected in the relaxation parameters of the entity (T1 and T2). An increase in T2 relaxation time is observed in case of ex-vivo human osteo-arthritic cartilage samples. 874. Independent Component Analysis and Artifact Removal in Human Calf Muscle Functional MRI Nicole Damara Fichtner1,2, Ewald Moser1, Michael Wolzt2, Albrecht Ingo Schmid1,2 1MR Centre of Excellence, Medical University of Vienna, Vienna, Austria; 2Dept. of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria Human calf muscle functional magnetic resonance imaging data, taken while simulating ischemia and acquired using echo planar imaging, can have many artifacts, particularly those from motion. Using temporal independent component analysis (ICA) on this type of data is a novel technique for separating the time-courses into various components. We show that it is possible to separate and remove artifacts from physiologically relevant information using temporal ICA. The remaining components can mostly be associated with various physiological effects, including those related to ischemia. The removal of artifacts and separation into components will improve the ease of further statistical analysis. Judong Pan1, Christoph Stehling2,3, Christina Muller-Hocker4, Benedikt Jakob Schwaiger5, John Lynch6, Michael Nevitt6 1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA , United States; 2Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 3Department of Clinical Radiology, University of Muenster, Germany; 4Technical University of Munich, Germany; 5Ludwig-Maximilians University of Munich, Germany; 6Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, United States Quadriceps strength has been extensively studied in relationship to knee osteoarthritis (OA). However, the role of vastus lateralis and vastus medialis in OA remains unclear. We examined 176 non-symptomatic subjects with risk factors for OA selected from the Osteoarthritis Initiative incidence cohort using cartilage T2 mapping technique and 3 Tesla MRI morphological analyses. We found that higher vastus lateralis to medialis cross-sectional area ratio is associated with significantly lower cartilage T2 values and less morphological abnormalities detected by MRI. Our data suggested that vastus lateralis/medialis balance may play an important role in the pathogenesis of early OA. 876. Extra-Orbital Muscle T2 Relaxation Time and Clinical Activity in Thyroid Eye Disease Laura Mancini1,2, Rathie Rajendram3, Jimmy Uddin3, Richard W J Lee4, Geoffrey E. Rose3, Tarek Yousry1,2, Katherine Miszkiel1,3, John S. Thornton1,2 1Lysholm Dept Neuro-radiology, National Hospital for Neurology and Neurosurgery, Univ College London Hospitals NHS Foundation Trust, London, United Kingdom; 2Academic Neuroradiological Unit, Institute of Neurology, University College of London, London, United Kingdom; 3Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; 4Academic Unit of Ophthalmology, Clinical Science at South Bristol, University of Bristol, Bristol, United Kingdom This study shows that there is correlation between T2 relaxation values in the extra-orbital muscles of patients with thyroid eye disease and Clinical Activity Score (CAS). CAS is the gold-standard measure of disease activity, considered to reflect the degree of orbital inflammation, while T2-weighted images are sensitive to changes in tissue water content concomitant with extra-orbital muscle inflammation. This study represents a validation of T2 measurements as outcome measures for studies of interventions in TED. T2 measures have therefore the potential to improve the quality of data reported in Randomised Control Trials. 877. In Vivo Detection of Deoxymyoglobin in Skeletal Muscle by 1H-MRS at 7T Katja Heinicke1,2, Ivan Dimitrov3,4, Jimin Ren3, Deborah Douglas3, Andrew G. Webb5, Craig R. Malloy3, Ronald G. Haller1,2 1Neuromuscular Center, Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, Dallas, TX, United States; 2Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States; 3Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 4Philips Medical Systems, Cleveland, OH, United States; 5Department of Radiology, dC.J. Gorter High Field Magnetic Resonance Center, Leiden University Medical Center, Leiden, Netherlands 1H-magnetic resonance spectroscopy (1H-MRS) can be used to noninvasively determine oxygen tension in human skeletal muscle. The purpose of this pilot study was to investigate the feasibility to detect the deoxy-Mb signal in skeletal muscle using 1H-MRS in ultra-high fields (7 Tesla). Spectra were acquired on a whole-body 7T scanner using a single-loop linear T/R surface coil with 10-cm diameter. Deoxy-Mb signal was observed in calf muscle in three healthy subjects during ischemia with 160-240 mmHg cuff pressure applied above the knee. The study demonstrates the feasibility of measuring deoxy-Mb in skeletal muscle using 1H-MRS at 7T.
Li-Wen Lee1,2, Po-Wah So3, Jimmy D. Bell1 1Metabolic and Molecular Imaging Group, MRC Clinical Sciences Centre, Hammersmith Hospital Campus, Imperial College London, London, United Kingdom; 2Department of Diagnostic Radiology, Chang Gung Memorial Hospital, Chang Gung Univeristy College of Medicine, Chiayi, Taiwan, Taiwan; 3Preclinical Imaging Unit, King's College London, Institute of Psychiatry, James Black Centre, Denmark Hill Campus, London, United Kingdom Glucose homeostasis is regulated by β-cell insulin secretion, peripheral glucose uptake and hepatic glucose production. We applied manganese-enhanced magnetic resonance imaging (MEMRI), utilising Mn2+ as a surrogate marker for Ca2+, to assess Ca2+-related processes involved in glucose homeostasis. MEMRI was performed following i.p. glucose or vehicle and signal intensity (SI) measured to assess Mn2+ distribution. MEMRI showed a significant increase in SI in skeletal muscle and the pancreas following glucose challenge but not in the liver. Thus, MEMRI can be used to assess changes in skeletal muscle glucose uptake and β-cell insulin secretion in vivo. Dimitrios C. Karampinos1, Christopher P. Hess1, Konstantinos Arfanakis2, Suchandrima Banerjee3, Eric T. Han3, Thomas M. Link1, Sharmila Majumdar1 1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States; 3Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States Fiber direction measurements in skeletal muscle DTI are limited by low precision because of the low SNR of muscle diffusion-weighted MRI and the low anisotropy of muscle diffusion tensor. However, in most skeletal muscles, fibers have a preferential orientation. In the present work, a priori assumptions about the dominant fiber orientation are used to derive non-uniform diffusion encoding schemes that minimize the elliptical cone of uncertainty. Simulations show that optimized schemes can decrease the fiber direction uncertainty up to 37% relative to uniform schemes. Preliminary in vivo results in the human tibialis anterior muscle are presented. Dimitrios C. Karampinos1, Suchandrima Banerjee2, Kevin F. King3, Eric T. Han2, Thomas M. Link1, Sharmila Majumdar1 1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States; 3Applied Science Laboratory, GE Healthcare, Waukesha, WI, United States Skeletal muscle DTI fiber reconstruction close to the aponeuroses is challenging because of partial volume effects. The spatial resolution of skeletal muscle single-shot DW-EPI is limited by the low SNR of muscle DWI and the high sensitivity of single-shot EPI to off-resonance effects. In the present work, eddy-current compensated diffusion-weighted stimulated echo preparation is used to increase SNR and is combined with SENSE to decrease the length of EPI readout. Theoretical results for the SNR efficiency of stimulated echo preparation with SENSE are derived and in vivo tensor maps of the calf muscles with an in plane resolution of 1.56x1.56 mm2 are presented. Julien Gondin1, Virginie Callot2, Patrick J. Cozzone2, David Bendahan2, Guillaume Duhamel2 1Centre de Résonance Magnétique Biologique et Médicale (CRMBM) - UMR CNRS 6612, Faculté de Médecine , Université de la Méditerranée, Marseille, France; 2Centre de Résonance Magnétique Biologique et Médicale (CRMBM) - UMR CNRS 6612, Faculté de Médecine, Université de la Méditerranée, Marseille, France We investigated whether the DTI metrics were sensitive enough to structural skeletal muscle fiber changes induced by both passive shortening and lengthening of the thigh muscles. Eight healthy male subjects were examined in a 1.5T whole-body MRI scanner. Images were randomly recorded from the mid-thigh region with the knee joint positioned at 0° and at 45°. Both the vastus lateralis and biceps femoris muscles showed changes in diffusion properties between the two positions whereas the DTI metrics of RF muscle were kept constant. We hypothesized that the specifc changes in water diffusivity observed in this study, reflect nonuniform microstructure changes among the thigh muscles due to their complex muscle-tendon architectures.
882. Assessment of Critical Limb Ischemia Using MRI Samuel Alberg Thrysoe1, Steffen Ringgaard, Khiem D. Hyunh2, William P. Paaske2 1MR-Center, Aarhus University Hospital Skejby, Aarhus, N, Denmark; 2Dept. of Vascular Surgery T, Aarhus University Hospital Skejby We used T2, T2*, and T2 maps to assess critical limb ischemia (CLI) using MRI. Neither T2* nor T2 were found to be able to discriminate patients with severe ischemia from normal controls. However, T2-values differed significantly (P=0.011, CI95=[5.6;29.7]) between patients (T2=57.4 ± 7.9 ms) and controls (T2=39.7 ± 3.3 ms). The observed difference is attributed to increased edema in patients suffering from CLI. Nina F. Schwenzer1,2, Christina Schraml1,2, Ina Kötter3, Jörg C. Henes3, Claus D. Claussen1, Fritz Schick2, Marius Horger1 1Department of Diagnostic and Interventional Radiology, University Hospital of Tübingen, Tübingen, BW, Germany; 2Department of Diagnostic and Interventional Radiology, Section on Experimental Radiology, University Hospital of Tübingen, Tübingen, BW, Germany; 3Department of Internal Medicine II, University Hospital of Tübingen, Tübingen, BW, Germany Systemic sclerosis is an autoimmune disease characterized by fibrosis, predominantly of the skin and vessels but also of internal organs and the skeletal muscle. Diffusion tensor imaging (DTI) is able to display diffusional characteristics of tissue. It seems plausible that water diffusivity within the muscle will change due to inflammation and subsequent fibrosis. Our results showed that the mean diffusivity increased in affected muscle groups while the fractional anisotropy did not change compared to healthy volunteers. This might be explained by the fact that the inflammatory processes affect mainly the perimysium of the muscle while the muscle fiber remains unchanged. Musculoskeletal Pot Luck Hall B Wednesday 13:30-15:30 884. Bloch Simulations of UTE, WASPI and SWIFT for Imaging Short T2 Tissues Michael Carl1, Jing-Tzyh Alan Chiang2, Eric Han1, Graeme Bydder2, Kevin King1 1GE Healthcare, Waukesha, WI, United States; 2University of California, San Diego Three specialized sequences designed to image short T2 tissues are Ultrashort TE (UTE) imaging, Water And Fat Suppressed Projection Imaging (WASPI), and SWeep Imaging with Fourier Transformation (SWIFT). We present theoretical work including Bloch simulations to investigate the T2 blurring characteristics of these three techniques. Simulated images obtained with WASPI and SWIFT show comparable T2 blurring, and slightly increased blurring with the UTE technique. 885. High Resolution Diffusion Tensor MRI of Rabbit Tendons and Ligaments at 11.7T Aman Gupta1,2, Weiguo Li1, Glenn T. Stebbins1,3, Richard L. Magin1, Vincent M. Wang1,2 1Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States; 2Department of Orthopedic Surgery, Rush University Medical Center, Chicago, IL, United States; 3Department of Neurosciences, Rush University Medical Center, Chicago, IL, United States Low grade tendon and ligament injuries are challenging to delineate on conventional MRI. This study presents results of 11.74T DTI analyses of rabbit MCL ligament and SemiT tendon. FA and MD(x10-6 mm2/s) values for SemiTs (n=6) were 0.66 and 1388, respectively, and for MCLs (n=4) were 0.47 and 1255. 3D tractography graphically depicted the spatial distribution of parallel, well organized collagen bundles. To our knowledge, this is the first study that investigates the microstructure of these tissue types using 3D DTI at high magnetic field. High Field DTI provides more rigorous data regarding tissue structural integrity compared to conventional MRI. 886. Three-Dimensional MRI Assessment of Median Nerve Variability in the Carpal Tunnel Daniel Ross Thedens1, Jessica E. Goetz2, Nicole M. Kunze2, Thomas E. Baer2, Ericka Lawler2, Thomas D. Brown2 1Radiology, University of Iowa, Iowa City, IA, United States; 2Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA, United States An important consideration in the evaluation of the biomechanics of the tendons and median nerve in the carpal tunnel is the normal range of variation in their conformation and relative arrangement within the tunnel under otherwise equivalent external conditions. The purpose of this study was to investigate the range of median nerve deformation and position within the tunnel over a series of imaging evaluations and following a set of specific pre-scan activities. The results demonstrate the complex motion and deformation of the median nerve in both neutral and flexed wrist positions. 887. Isotropic MRI of the Upper Extremity with 3D-FSE-Cube Lauren M. Shapiro1, Alicia M. Jenkins1, Kathryn J. Stevens1, Charles Q. Li1, Weitian Chen2, Anja C.S. Brau2, Brian A. Hargreaves1, Garry E. Gold3 1Radiology, Stanford University, Stanford, CA, United States; 2Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States; 3Radiology, Bioengineering, Orthopedics, Stanford University, Stanford, CA, United States Two-dimensional fast spin-echo (2D-FSE) is commonly used to image the upper extremity, however it is limited by slice gaps, partial volume artifact and poor quality reformats. Three-dimensional fast spin-echo (3D-FSE-Cube) overcomes these limitations by acquiring isotropic data, allowing for reformations in oblique planes while decreasing exam time. Our study compared 2D-FSE with 3D-FSE-Cube at 3.0T in the upper extremity. 3D-FSE-Cube demonstrated similar or significantly higher signal-to-noise compared with 2D-FSE. 3D-FSE-Cube images were slightly worse than 2D-FSE with respect to blurring, artifacts, and overall image quality. 3D-FSE-Cube may improve visualization of complex upper extremity anatomy and make multiple 2D acquisitions unnecessary. Michael Bock1, Axel Joachim Krafft1, Florian Maier1, Hans H. Paessler2 1Medical Physics in Radiology, German Cancer Research Center (dkfz), Heidelberg, Germany; 2Center for Knee & Foot Surgery/Sports Trauma, ATOS Clinic, Heidelberg, Germany During sports activities such as skiing temperature changes of up to 10 K have been measured invasively. In this work we propose the use of MR temperature measurements in the knee where the thermal stimulation is performed outside the magnet. With a temperature-sensitive 3D FLASH sequence proton resonance frequency data are acquired before and after stimulation, and image co-registration is achieved with both a passive fixation device and an alignment post-processing algorithm to calculate phase difference maps. Annie Horng1, Matthias Pietschmann2, Mike Notohamiprodjo1, Peter Müller2, Maximilian F. Reiser1, Christian Glaser1 1Department of Clinical Radiology, University Hospitals LMU Munich Campus Grosshadern, Munich, Bavaria, Germany; 2Department of Orthopedic Surgery, University Hospitals LMU Munich Campus Grosshadern, Munich, Bavaria, Germany Shoulder-MRI using conventional TSE sequences often exhibit artifacts resulting in non-diagnostic images due to involuntary patient movement. A recent developed multishot T2-weighted sequence based on rotating rectangular read-out of k-space data (BLADE) is supposed to reduce motion artifacts. This study compared BLADE to a conventional fat-saturated TSE sequence used in musculoskeletal radiology, revealing significant reduction of motion artifacts, improvement of image quality, depiction of anatomical detail and improved diagnostic confidence of anterior labral lesions. Thus BLADE provides a promising alternative for examination of young, critically ill or claustrophobic patients, who express a higher probability for motion artifacts. 890. In Vivo Conductivity Imaging of Human Knee Using 3 MA Imaging Current Hyung Joong Kim1, Young Tae Kim1, Woo Chul Jeong1, Atul Singh Minhas1, Tae Hwi Lee1, O Jung Kwon2, Eung Je Woo1 1Biomedical engineering, Kyung Hee University, Yongin, Gyeonggi, Korea, Republic of; 2Medicine, Sungkyunkwan University, Seoul, Korea, Republic of In Magnetic Resonance Electrical Impedance Tomography (MREIT), we measure induced magnetic flux density subject to multiple injection currents to reconstruct cross-sectional conductivity images. Newly developed multi-echo pulse sequence in MREIT is expected to provide a higher magnitude image SNR and lower noise level in magnetic flux density data. Injecting 3 mA imaging currents into the human knee, we collected induced magnetic flux density data using the multi-echo pulse sequence. Reconstructed conductivity images using the harmonic Bz algorithm show good contrast among different parts of the subcutaneous adipose tissue, muscle, synovial capsule, and bone inside the knee Imaging Metal with Magnets Hall B Thursday 13:30-15:30 Sven Månsson1, Gunilla Müller2, Daniel Alamidi3, Jonas Svensson1, Markus Müller2 1Medical Radiation Physics, Lund University, Malmö, Sweden; 2Radiology, Lund University, Malmö, Sweden; 3Radiation Physics, University of Gothenburg, Gothenburg, Sweden Metal-on-metal hip resurfacing implants are suitable for young, active patients. However, there are indications that these implants fail more frequently than traditional implants. An early diagnosis of prosthetic failure would be facilitated by artifact-reducing MRI protocols. The purpose of this study was to investigate to which extent metal artifacts can be reduced, in the worst case of a stainless steel implant, by optimizing routine imaging protocols. The result on a patient with hip joint implant showed that metal artifacts can be substantially reduced, thereby permitting anatomical details to be visualized closer to the implant. Kevin M. Koch1, Matthew F. Koff2, Hollis G. Potter2, Kevin F. King1 1Applied Science Laboratory, GE Healthcare, Waukesha, WI, United States; 2Hospital for Special Surgery, New York, United States A variety of enhancements to the MAVRIC technique are described and demonstrated to produce minimal artifact images with sub-millimeter resolution in the near vicinity of total joint replacements. Clinically feasible scan times are achieved by using k-space corner-cutting, partial Fourier, and autocalibrated parallel imaging undersampling acquisition strategies. MAVRIC images are shown to dramatically reduce susceptibility artifacts while maintaining diagnostically relevant spatial resolution when compared to established 2D-FSE arthroplasty images. 893. MRI Near Metallic Implants Using SEMAC: Initial Clinical Experience Garry E. Gold1, Shreyas S. Vasanawala2, Wenmiao Lu3, Christina A. Chen2, Weitian Chen4, John M. Pauly5, Kim Butts Pauly2, Stuart B. Goodman, Brian A. Hargreaves2 1Radiology, Bioengineering, Orthopaedic Surgery, Stanford University, Stanford, CA, United States; 2Radiology, Stanford University, Stanford, CA, United States; 3Electrical and Electronic Engineering, Nanyang Tech., Singapore; 4Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States; 5Electrical Engineering, Stanford University, Stanford, CA, United States MRI around metallic implants such as total joint replacements has been limited due to artifacts. Recently a new method for reducing artifact near metal called Slice Encoding for Metal Artifact Correction (SEMAC) was described. This work compares the clinical performance of SEMAC versus 2D-FSE in an initial population of symptomatic patients with metal implants. Clinical management was changed in a substantial number of cases. Foot to Mouth Hall B Monday 14:00-16:00 894. High Spatial Resolution 3D MRI of the Larynx Using a Dedicated TX/RX Phased Array Coil at 7.0T Tobias Frauenrath1, Wolfgang Renz2, Jan Rieger1, Andreas Goemmel3, Christoph Butenweg3, Thoralf Niendorf1,4 1Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany; 2Siemens Medical Solutions , Germany; 3Chair of Structural Statics and Dynamics, RWTH, Aachen, Germany; 4Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt University, Berlin, Germany MRI holds great potential for elucidating laryngeal and vocal fold anatomy together with the assessment of physiological processes associated in human phonation. However, MRI of human phonation remains very challenging due to the small size of the targeted structures, interfering signal from fat, air between the vocal folds and surrounding muscles and physiological motion. These anatomical/physiological constraints translate into stringent technical requirements in balancing, scan time, image contrast, immunity to physiological motion, temporal resolution and spatial resolution. Motivated by these challenges and limitations this study is aiming at translating the sensitivity gain at ultra-high magnetic fields for enhanced high spatial resolution 3D imaging of the larynx and vocal tract. To approach this goal a dedicated two channel TX/RX larynx coil is being proposed. 895. Real-Time Imaging of the Temporomanibular Joint Motion Based on Golden Ratio Radial MRI Andreas Johannes Hopfgartner1, Olga Tymofiyeva1, Philipp Ehses1, Kurt Rottner2, Julian Boldt2, Ernst-Jürgen Richter2, Peter Michael Jakob1 1Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany; 2Prosthodontics, Dental School, University of Würzburg, Würzburg, Bavaria, Germany Static or pseudo-dynamic MRI of the TMJ does not allow for full analysis of the disc deformation and displacement during the mandibular motion. The purpose of this study was to develop a dynamic MRI technique for measurement of the TMJ with an arbitrary reconstruction window. The method uses a radial trajectory with a constant azimuthal profile spacing of 111.246°. Two kinds of measurements were performed: opening and closing of the mouth and biting into a cooled chocolate-covered caramel. Reconstruction was performed with a sliding window method and a KWIC filter. The method is suitable for diagnosis and therapy planning. 896. Micro-Magnetic Resonance Imaging of Limb Development: Insights Into the Basis of Clubfoot Suzanne Louise Duce1 1College of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom Clubfoot (CTEV) in humans is a malformation which affects about 4-in-1000 births; its aetiopathogenesis is unknown. We undertook a 3D μMRI study using 7.1T Bruker spectrometer, of a pma mouse model that has clubfoot-like hindfoot malformations. Wild-type and pma mouse musculoskeletal anatomy were compared. The pma hindfeet displays similar abnormalities (eg supination) to human CTEV. Embryonic hindfoot developmental studies showed initiation of pma hindfoot rotation is often delayed compared to wild-type, is slower and does not reach completion. If our results were extrapolated to humans, it supports the hypothesis that CTEV is due to incompletion foot rotation and angulation. 897. High-Resolution Interleaved Water-Fat MR Imaging of Finger Joints Wingchi Edmund Kwok1, Zhigang You1, Gwysuk Seo1, Christopher Ritchlin2, Johnny Monu1 1Department of Imaging Sciences, University of Rochester, Rochester, NY, United States; 2Allergy, Immunology and Rheumatology Division, University of Rochester, Rochester, NY, United States Insufficient resolution and chemical-shift artifacts in MRI of finger joints can hinder early diagnosis of arthritis. We used an interleaved water-fat (IWF) sequence and a dedicated RF coil to achieve high-resolution finger MRI without chemical-shift artifacts. A normal subject and six subjects with arthritis were studied. The high-resolution images revealed detailed structures of the finger joints. The IWF sequence gave more accurate depiction of subchondral bone thickness, and avoided false bone erosions shown in the regular sequence. It also allowed better visualization of ligaments and tendons. High-resolution IWF imaging should be useful for the diagnosis and treatment evaluation of arthritis. Spectroscopic Quantification Methodology Hall B Tuesday 13:30-15:30 898. The Case of the Missing Glutamine Ileana Hancu1, Mark Frye2, John Port2 1GE Global Research Center, Niskayuna, NY, United States; 2Mayo Clinic, Rochester, MN, United States A theoretical study is performed to understand the accuracy and repeatability of multiple pulse sequences in quantifying glutamine concentration at 3T. Variable repeatability (12% to >50%) and significant bias (-30% to +70%) is noted for the seven pulse sequences considered. Data acquired in vivo using three of the pulse sequences used for simulations matches the predicted repeatability well. Following correction for the expected bias of each pulse sequence, consistent glutamine measurements, all in the 1mM range, are reported with the 3 sequences. An explanation for the mismatch between the in vivo 1H MRS and ex vivo results is attempted. 899. Human Breast Lipid Composition Determination by in Vivo Proton MRS at 7T Ivan Dimitrov1, Deborah Douglas2, Jimin Ren2, Andrew G. Webb3, A Dean Sherry2, Craig R. Malloy2 1Philips Medical Systems, Cleveland, OH, United States; 2Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 3Radiology, Leiden University Medical Center, Leiden, Netherlands The role of diet and fat consumption in the pathogenesis of breast cancer is an important subject. We report on the non-invasive determination of lipid composition in human breast by 1H-MRS at 7T. Two respiratory-triggered TE-averaged STEAMs were performed in healthy volunteers where the second acquisition had all gradients inverted. T1 and T2 were also measured. Ten lipid peaks were typically resolved. The average lipid composition was 30.5% saturated, 48.4% mono-unsaturated, and 21.1% di-unsaturated. In conclusion, we have shown that a chemical analysis of lipids in breast tissue can be determined quite simply and non-invasively by proton MRS at 7T. 900. Is Human Glial TCA Cycle Rate Faster Than We Thought? Napapon Sailasuta1, Brian D. Ross1,2 1Clinical MR Spectroscopy, Huntington Medical Research Institutes, Pasadena, CA, United States; 2Rudi Schulte Research Institute, Santa Barbara , CA, United States 13C MRS uniquely quantifies glutamine-glutamate cycle rate in either neurons or glia, driven by the substrate selection of their cellular membrane transporters. Glial metabolic rate is of increasing interest as the range of human neurological disorders which appears selective to glia (Alzheimers, MS; TBI; epilepsy) increases and as selective medications are designed to correct such abnormalities. 13C enrichment followed by localized 13C MRS detection of many specific products has provided valuable background. In a recent study we encountered a mismatch between prior metabolic models and a simplified method described here with a 5 10 fold difference in the measured rate. 901. Quantification Precision of Human Brain 1H MRS at Different Field Strengths: A Simulation Study Dinesh K. Deelchand1, Isabelle Iltis1, Pierre-Francois Van de Moortele1, Pierre-Gilles Henry1 1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States 1H MRS allows measurement of the concentration of a number of brain metabolites in vivo. It is generally accepted that the precision of quantification improves with B0. In principle, two factors may contribute to this increase in quantification precision: higher signal-to-noise ratio (SNR) and higher spectral resolution. In this work, we assess the respective contribution of these two factors using simulations. We report that, especially above 3-4 Tesla, increased SNR is the major contributor to the increase in quantification precision, as the gain in chemical-shift dispersion is offset by the increase in linewidth in vivo. 902. Regularized Spectral Lineshape Deconvolution Yan Zhang1, Shizhe Li1, Jun Shen1 1National Institute of Mental Health, Bethesda, MD, United States The process of lineshape deconvolution is an inverse problem. A new referencing deconvolution method is proposed, which uses Tiknohov regularization to restrain the noise amplification. To determine the optimal regularization, the noise to signal ratio in frequency domain was defined as a function of the regularization parameter. It was found that this function yielded a well-defined L-curve with the transition point that marks the optimal regularization parameter. The method was validated on 1H spectral data which were acquired on human brain with single voxel at 3T. The spectral quality was markedly improved after the data were processed with the proposed method. Hubert Desal1, Nashiely Pineda Alonso2, Serge Akoka2 1Neuroradiology, CHU de Nantes, Nantes, PdL, France; 2Chemistry, Université de Nantes, CEISAM, UMR 6230, Nantes, PdL, France The ERETIC method is a promising avenue of research for absolute concentration quantification by MRS. However, in its initial form, this technique cannot be implemented on most clinical MR scanners. We propose a new strategy, which consists in transmitting the ERETIC signal before the localized spectroscopy acquisition. This approach was evaluated on phantoms and on volunteers. The results were compared to those obtained using the water signal as reference. A very good correlation between the values obtained using the two methods was observed. Moreover, the ERETIC method overcomes many of the drawbacks of the other absolute quantification methods. 904. Sampling Strategy Effects on in Vivo 2D J-Resolved Spectroscopy Quantification Tangi Roussel1, Sophie Cavassila1, Hélčne Ratiney1 1CREATIS, CNRS UMR 5220, Inserm U630, INSA-Lyon, Université de Lyon 1, Université de Lyon, Villeurbanne, France Till now, in vivo two-dimensional spectroscopy related studies did not investigate sampling strategies of the indirect dimension as a way of improving the quantification of metabolite concentrations. This paper presents a study carried out on simulated J-PRESS data containing macromolecular contamination. 2D J-Resolved spectroscopy quantification accuracy was evaluated for several sampling strategies and compared to 1D MRS quantification accuracy. In vivo 2D quantification following these strategies is shown. By handling macromolecular contribution by truncation strategy, a 2D MRS experiment leads to a more accurate quantification compared to 1D MRS time equivalent experiment, as demonstrated by a reduction of bias and standard deviation.
Alexander Gussew1, Marko Erdtel1,2, Reinhard Rzanny1, Juergen R. Reichenbach1 1Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital, Jena, Germany; 2University of Applied Sciences Jena, Jena, Germany This work describes in vitro and in vivo validation of absolute quantitation of 1H-MRS brain data with respect to heterogeneous tissue distributions within the MRS-volume. NAA concentrations were estimated from metabolite and water spectra obtained from MRS-voxels containing different metabolite and water concentrations and were compared with nominally adjusted values. The maximal error was 4% compared to 41%, if the tissue heterogeneity was neglected. Inter-individual distributions of NAA-, Cr- and tCho-concentrations obtained in insular cortex of volunteers had twice less scatter when taking into account the heterogeneous tissue composition in the voxel. Andrew Borgert1,2, Kelvin O. Lim1,2, Pierre-Gilles Henry1,3 1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States; 2Department of Psychiatry, University of Minnesota, Minneapolis, MN, United States; 3Department of Radiology, University of Minnesota, Minneapolis, MN, United States Spectral fitting methods such as commercial metabolomics software (eg, Chenomx) or capabilities built into NMR system software (eg, Varian or Bruker) require significant user input and are generally not amenable to automation, making them time-consuming, cumbersome, and prone to user error. To address these issues, we have adapted the LCModel software package for use with high resolution in vitro NMR data, allowing for automated and consistent analysis of such data. This adaptation utilizes a simulated basis set, with basis spectra generated for the majority of individual protons within each metabolite, as opposed to the metabolite as a whole. 907. Simulating Human Brain Glutamate FMRS at 7.0 T to Determine Minimum SNR Requirements Reggie Taylor1,2, Jean Théberge1,2, Peter Williamson, 1,3 1Medical Biophysics, University of Western Ontario, London, ON, Canada; 2Lawson Health Research Institute, London, ON, Canada; 3Department of Psychiatry, University of Western Ontario, London, ON, Canada Human brain glutamate fMRS has the potential to provide dynamic information regarding normal and abnormal glutamate metabolism. With ultra-high field magnets (≤7T) increased spectral dispersion and SNR should result in more precise fMRS but how much SNR is required is not known. Using simulations of an in vivo spectrum acquired with a STEAM sequence (TE/TM 6/32ms) at 7T minimum numbers of spectra required to detect a 3% concentration change in glutamate between rest and activation were determined for various SNRs. A minimum SNR of 212 was needed to detect the 3% change when comparing only one spectrum from each state. 908. Ultrafast 2D High-Resolution COSY Spectra in Inhomogeneous Fields Congbo Cai1, Fenglian Gao1, Shuhui Cai1, Zhong Chen1 1Departments of Physics and Communication Engineering, Fujian Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, Fujian, China High-resolution COSY spectra can provide more information than 1D spectra. Recently, our group proposed a method to achieve high-resolution COSY spectra under inhomogeneous fields based on the intermolecular multiple-quantum coherences (iMQCs). However, 3D acquisition is necessary for a 2D COSY spectrum, which makes the experiment rather time-consuming. In this study, we introduced Hadamard technique to speed up the acquisition greatly. A high-resolution iMQC COSY spectrum can then be obtained in less than 10 minutes under inhomogeneous fields. Such a technique would widen the application field of iMQC methods. 909. Handling Arbitrary Unknown Line-Shape Without Introducing Extra Parameters. Emil Popa1, Enrico Capobianco2, Jan Willem van der Veen3, Ronald de Beer4, Dirk van Ormondt5, Danielle Graveron-Demilly1 1Université Lyon 1, Villeurbanne, France; 2CRS4 Bioinformatics Laboratory, Pula (Cagliari), Italy; 3NIH, NIMH, Bethesda, United States; 4Delft University of Technology; 5Applied Physics, Delft University of Technology, Delft, Zuid Holland, Netherlands This work concerns a new way of dealing with in vivo spectral lineshapes for the case that a reference line is not available. It is based on dual-criterion non-linear least-squares fitting. All data-points are used simultaneously, in conjunction with the general a priori knowledge that a lineshape can be confined to a certain frequency region. The experimental lineshape at hand can be arbitrary, including asymmetric shapes. Modelling with analytical mathematical functions like splines, wavelets, or decaying sinusoids is circumvented. As a result, setting of hyper-parameters by a user is avoided. This favours automation. Alan Bainbridge1, Giles Kendall2, Enrico DeVita3, Cornelia Hagmann2, Andrew Kapetanakis2, Ernest Cady1, Nicola Robertson2 1Medical Physics and Bioengineering, UCL Hospitals NHS Foundation Trust, London, United Kingdom; 2Academic Neonatology, EGA UCL Institute for Womens Health, University College London, London, United Kingdom; 3UCL Hospitals NHS Foundation Trust, Medical Physics and Bioengineering, London, United Kingdom Therapeutic cerebral hypothermia is an effective and safe treatment for perinatal asphyxial encephalopathy. Precise knowledge of regional brain temperature is needed in order to optimise therapeutic hypothermia. Proton MRS can be used to estimates regional brain temperature. Reliable absolute temperature measurement depends on good calibration data and robust clinical spectrum acquisition. Serial acquisition of subspectra allows both removal of motion-corrupted data and frequency correction of the remaining subspectra to remove effects of static magnetic field decay. The magnetic field decay correction significantly reduced fitted peak linewidths and increased the precision of the measurement. Jacob Penner1,2, Andrew Curtis1,2, Martyn Klassen1, Joseph Gati1, Matthew Smith3, Michael J. Borrie3,4, Robert Bartha1,2 1Centre for Functional and Metabolic Mapping, Robarts Research Institute, London, ON, Canada; 2Medical Biophysics, University of Western Ontario, London, ON, Canada; 3Division of Aging, Rehabilitation, and Geriatric Care, Lawson Health Research Institute, London, ON, Canada; 4Department of Medicine, University of Western Ontario, London, ON, Canada The purpose of this study was to determine the optimal inversion time to null metabolite signals allowing accurate measurement of the macromolecule baseline for quantitative 1H MR spectroscopy at 7T. Spectra were acquired within a phantom using single-voxel localization by adiabatic selective refocusing (LASER). The TI values that would result in complete suppression of NAA and Cr were found to be 0.47 seconds and 1.27 seconds, respectively. Furthermore, T1 values were found to be 1.28 seconds for NAA and 2.45 seconds for Cr. Future work will extend this method to determine the optimal TI values for in-vivo metabolite suppression. Yuqing Huang1, Shuhui Cai1, Zhong Chen1,2, Jianhui Zhong2 1Department of Physics, Xiamen University, Xiamen, Fujian, China; 2Departments of Radiology and Biomedical Engineering, University of Rochester, Rochester, NY, United States The decoupled proton NMR spectroscopy can effectively simplify the spectra and improve the spectral resolution and sensitivity. In this abstract, two new pulse sequences based on homonuclear and heteronulcear intermolecular single-quantum coherences (iSQCs) were presented for high-resolution decoupled spectra in inhomogeneous fields. The experimental results indicate that the sequences are useful for obtaining high-resolution decoupled spectra in modest to severe inhomogeneous fields. 913. Comparison of Quantification Strategies for Clinical 1H-MRS Using a Large Spectroscopy Database Roberto Tarducci1, Andy Simmons2, Monica Pace3, Patrizia Mecocci3, Eric Westman4, Gianni Gobbi1 1S.C. di Fisica Sanitaria, Azienda Ospedaliera di Perugia, Perugia, Italy; 2Centre for Neuroimaging Sciences, King's College - London Institute of Psychiatry, London, United Kingdom; 3Department of Clinical and Experimental Medicine, University of Perugia - Institute of Gerontology and Geriatrics, Perugia, Italy; 4Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
914. Localized 31P Saturation Transfer in Rat Brain Vladimir Mlynarik1, Cristina Cudalbu1, Yves Pilloud1, Rolf Gruetter1,2 1Laboratory of Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 2Departments of Radiology, Universities of Lausanne and Geneva, Switzerland Phosphorus saturation transfer technique is sensitive to experimental imperfections such as partial direct saturation of the measured peak, incomplete saturation of the other peak under exchange and a problematic localization, which is usually done by an active volume of a surface coil used as a transceiver. In our study we compared the PCr <> γ-ATP saturation transfer experiment using 1D ISIS localization combined or not combined with outer volume saturation. We observed a contaminating component from muscles in the PCr signal when using the 1D ISIS only. This contamination led to an underestimation of the calculated rate constant of the creatine kinase reaction. 915. Non-Invasive Measurement of Fibrin Concentration by Fast Field-Cycling NMR Technique Lionel Marc Broche1, Saadiya Rashid Ismail1, Nuala A. Booth2, David J. Lurie1 1Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, Scotland, United Kingdom; 2Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom In this work we examine the feasibility of measuring the content of fibrin clots, which is the protein network that stabilises a thrombus, using fast field-cycling NMR. Fibrin, like proteins in general, is rich in 14N and its mobility is reduced due to the web-like structure of a clot. These two conditions are the cause of the apparition of a specific signal in the 1H dispersion plot, called the quadrupole signal, which can be used to measure the fibrin content. 916. New View of Human Brain PH: MR Monitoring of Bicarbonate Napapon Sailasuta1, Brian D. Ross1,2 1Clinical MR Spectroscopy, Huntington Medical Research Institutes, Pasadena, CA, United States; 2Rudi Schulte Research Institute, Santa Barbara , CA, United States Human brain pH is a significant clinical measure usually accomplished directly through implantable pH electrodes, or indirectly from HCO and C02 together with Henderson-Hesselbach tables. In recent 13C MRS studies we were able to directly quantify bicarbonate in resting human brain and to monitor the changes produced by short or long term fasting. pH estimated from 13C HC03 differed significantly from accepted normal values and those obtained by direct 31P MRS. Possible confounds, including binding, compartmentation and T1/T2 variances are considered before concluding that human brain [bicarbonate] is lower than previously thought. Natalie May Zahr1,2, Meng Gu3, Dirk Mayer, 2,3, Daniel Mark Spielman3, Edith V. Sullivan1, Adolf Pfefferbaum, 12 1Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States; 2Neuroscience, SRI International, Menlo Park, CA, United States; 3Radiology, Stanford University, Stanford, CA, United States Glutamate (Glu) and glutamine (Gln) were quantified individually to determine the effects of ethanol (EtOH) on rat brain metabolites. CT-PRESS was acquired at baseline (MRS1) and after 16 (MRS2) and 24 weeks (MRS3) of EtOH exposure. Previous analysis revealed an increase in the combined resonances of Glu+Gln (i.e., Glx) with escalating EtOH doses. The current investigation unveils that underlying the increase in Glx at MRS2 was an increase in Gln, and underlying the increase in Glx at MRS3 was an increase in Glu. These results caution against interpretations regarding changes to Glx as a surrogate marker for Glu or Gln. 918. Quantization of ME-COSI Data with Prior Knowledge Fitting Gaurav Verma1, Neil Wilson2, Scott Logan Lipnick2, Nagarajan Rajakumar3, Michael Albert Thomas3 1Biomedical Engineering, UCLA, Los Angeles, CA, United States; 2Biomedical Physics, UCLA, Los Angeles, CA, United States; 3Radiological Sciences, UCLA, Los Angeles, CA, United States To quantify the 4D data generated by ME-COSI, eighteen scans of a physiological gray matter phantom were acquired. A central voxel from each acquisition was extracted and its spectrum was fitted using ProFit, a prior knowledge fitting algorithm for 2D MRS. Cramer-Rao Lower Bounds for the fit measured with ProFit were 0.3 to 16.5 for most metabolites. Across all acquisitions the coefficient of variation ranged from 2 to 21% for most metabolites. Glutamate/glutamine were overestimated possibly due to inclusion of an erroneous peak during quantization, and lactate peak showed poor fitting and reproducibility, likely due to its low concentration. Methodology for MRS of Cells, Body Fluids, etc. Hall B Wednesday 13:30-15:30 Ren-hua Wu1,2, Hui Wang3, Poublanc Poublanc2, Karel terBrugge2, David Mikulis2 1Medical Imaging, Shantou University, Shantou, Guangdong, China; 2Medical Imaging, University of Toronto, Toronto, ON, Canada; 3Learning Science Center, Southeast University, Nanjing, China Our aim was to know the relationship between oxygen inhalation and mitochondrial activity, and relationship between vision and mitochondrial activity as well. Eleven healthy volunteers underwent 31P MRS examination. ¦ĆATP, ¦ĮATP, ¦ĀATP, and ”°potential of hydrogen”± (pH) were measured. We can observe increased ¦ĆATP, ¦ĮATP, and ¦ĀATP peaks on the 3rd scan breathing hyperoxic air with eyes opening. Brain mitochondrial activities were increased and more ATPs were produced after oxygen inhalation in healthy volunteers. More energy is needed in visual status. 920. Bacteria-Specific Biomarkers in Mouse-Models of Infections Investigated by NMR Spectroscopy Verena Hoerr1, Lori Zbytnuik2, Paul Kubes2, Hans Vogel1 1Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada; 2Department of Physiology and Biophysics, University of Calgary, Calgary, Alberta, Canada In mouse-models of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa infections, serum was investigated by 1H NMR spectroscopy and distinguished by statistical pattern recognition techniques. By combining the results of the in vivo study with footprints of culture experiments, potential bacteria-specific biomarkers were identified. We also compared serum metabolite changes caused by lipopolysaccharides (LPS) treatment and E. coli infection in both wild-type and Toll-like receptor 4 (TLR4) deficient mice. In TLR4 deficient mice the immune response upon LPS treatment was suppressed. Taken together, our approach allows us to distinguish between innate immune and direct bacterial effects during an infection. Valeria Righi1,2, Caterina Constantinou3, Meenu Kesarwani3, Laurence G. Rahme3, A Aria Tzika1,2 1NMR Surgical Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States; 2Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, United States; 3Molecular Surgery Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States We tested the feasibility of H1 High Resolution Magic Angle Spinning (HRMAS) NMR in determining metabolic profiles of live bacteria. We used Pseudomonas aeruginosa, a human opportunistic pathogen responsible for chronic and acute infections, and a major cause of morbidity and mortality in cystic fibrosis patients. We found that HRMAS is powerful technique for monitoring the metabolic fingerprint of in vivo models, including live bacterial cells. This technique may prove to be a helpful tool in gene function validation, the study of pathogenesis mechanisms and the testing of anti-bacterial agents. Valeria Righi1,2, Mattia Di Nunzio1,3, Francesca Danesi1,4, Elisa Boschetti1,4, Luisa Schenetti2, Adele Mucci2, Alessandra Bordoni1,4, Vitaliano Tugnoli1 1Dipartimento di Biochimica "G. Moruzzi", Universita' di Bologna, Bologna, Italy; 2Dipartimento di Chimica, Universita' di Modena, Modena, Italy; 3Nutrition Research Center , Bologna, Italy; 4Nutrition Research Center, Bologna, Italy Cardiovascular diseases (CVD) are responsible for significant morbidity and mortality throughout the world. We present a first investigation using HR-MAS NMR Spectroscopy in combination with GC/MS of neonatal rat cardiomyocytes supplemented with two different PUFAs, EPA and DHA, in order to understand the metabolic change occurring in these cells following the increase of their n-3 PUFA content. EPA and DHA are of special importance for human health, and fish oil feeding has been associated to reduced mortality in several studies. Yangyang Wei1, Huaizhou Jiang2, Jingjing Xu1, Jiyang Dong1, Shuhui Cai1, Zhong Chen1 1Department of Physics, Fujian Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, Fujian, China; 2Hubei University of Traditional Chinese Medicine, Wuhan, Hubei, China The biochemical variations of serum from control and Wilson”Æs disease (WD) rats were investigated using NMR-based metabolomics. Two groups can be discriminated according to the score plot of principle component analysis. The WD group shows increased levels of lactate, glycoprotein, glutamine, creatine, creatinine£¬arginine and decreased levels of glucose, trimethylamine-N-oxide, betaine, lipid and choline. The results may further our understanding of the disease. J A. Welge1,2, Richard A. Komoroski2 1Environmental Health, University of Cincinnati, Cincinnati, OH, United States; 2Center for Imaging Research, University of Cincinnati, Cincinnati, OH, United States Using prior 31P NMR data for the composition of phospholipid (PL) and PL metabolites in postmortem schizophrenic and matched control brains, we searched for multivariate regression models to classify these samples. Because the number of measurements exceeded the number of samples, variable selection was required. We employed Akaikes Information Criterion in conjunction with repeated cross-validation using random splits of the data into model-building and validation subsets. This procedure addressed the risk of over-fitting the sample data and generated predictions from data not used to select the model. Certain metabolites that were not individually significant produced accurate classification when modeled jointly. 925. Probing Radiation Biomarkers in Human Urine by 1H NMR Congju Chen1, David J. Brenner2, Truman R. Brown1 1Department of Radiology, Columbia University, New York, NY, United States; 2Center for Radiological Research, Columbia University, New York, NY, United States In previous work we have identified a dozen biomarkers in urine from radiation-exposed mice by NMR spectroscopy. The mouse model allowed us to understand the effect of key parameters such as dose, time post-exposure on the urinary biomarkers. To validate these biomarkers in humans, in this work we investigate urinary biomarkers associated with radiation exposure in acute leukemia patients undergoing a series of total body irradiation treatments in preparation for a hematopoietic stem cell transplant. The results indicated that besides some common urinary radiation biomarkers from both mice and human, there are some unique radiation signatures in human urine. 926. Acute Effect of Gamma Irradiation in Mice by NMR Based Metabolic Profiling of Urine Ahmad Raza Khan1, Poonam Rana1, M Memita Devi1, Shubhra Chaturvedi2, Subash Khushu1 1NMR Research Centre, INMAS, Delhi, India; 2Division and Cyclotron & Radiopharmaceutical Sciences, INMAS, Delhi, India A high resolution 1H NMR spectroscopy based metabonomic approach has been used to study acute effect of gamma irradiation at biochemical levels. Urine samples were collected from mice at 6, 24 and 96 hrs post irradiation with dose of 3, 5 and 8 Gy. Significant changes were observed in high dose of gamma irradiation even after 6 hrs, while maximum changes observed in low and moderate dose after 24 hrs of exposure. These alterations in metabolites could be helpful for identification of potential biomarkers associated with radiation induced changes and may find applications in biological dosimeters. Robert Leslie Davidson1, Sonali S. deSilva1, Simon J. Doran1, Geoffrey S. Payne1 1Clinical Magnetic Resonance, Institute of Cancer Research, Sutton, Surrey, United Kingdom Statistical Total Correlation Spectroscopy (STOCSY) applied to contaminated 1H HR-MAS spectra of cervical tissue samples. 2D and 1D STOCSY plots show the highly correlated, structurally linked, contaminant peaks and allow identification of the compound as lignocaine (anaesthetic). The lack of other correlations with these peaks suggests that there is no significant, observable metabolic effect of lignocaine on these spectra. This means that a simple peak removal algorithm, such as that used to remove residual water, would be enough to allow this data to be analysed by pattern recognition techniques. Zhi-Feng Xu1, Chong-Yang Shen2, Lin-Ping Wu2, Ye-Yu Xiao, Yao-Wen Chen, Ren-Hua Wu 1medical imging, the 2nd Affiliated Hospital, the Medical College of Shantou University, shantou, guangdong, China; 2Multidisciplinary Research Center of Shantou University, shantou, guangdong, China Our study, we research the properties of the NMR spectroscopy of the human mesenchymal stem cells (MSCs) and non-stem cells (EC109), in order to demonstrate that whether the 1.28ppm is unique for the neural progenitor cells (NPCs). Meanwhile, we want to approach this biomarker changes with adipogenic differentiation£¬and to study the relationship of the 1.28 ppm biomarker with mobile lipid droplets. In brief, we found that the 1.28ppm also resides in MSCs, and this biomarker increased remarkablely after 2 weeks adipogenic differentiation. In addition, this biomarker is not just due to the lipid droplets in the cytoplasm. as the previous studies advanced. Other Spectroscopy Methodology Hall B Thursday 13:30-15:30 Alexander Fuchs1, Anke Henning1, Peter Boesiger1 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland The ability of 2D spectroscopy to spread spectral information that is otherwise hard to detect into a second frequency dimension makes these type of techniques very interesting. On ultra-high field strength the short relaxation time of interesting metabolite signals makes commonly used localized sequneces like L-COSY or PRESS localized COSY impractical. Hence a suitable localized COSY sequence at 7T was implemented using the SPECIAL sequence. The successful application of SPECIAL for localized COSY at 7T is demonstrated in a phantom and in-vivo measurements.
930. SPECIAL-J-Resolved Spectroscopy at 7T Alexander Fuchs1, Anke Henning1, Peter Boesiger1 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland Unambiguous detection of coupled spin systems like Glutamate, Glutamine or GABA can be a quite challeging task with regular one dimensional spectroscopy. 2D J-resolved spectroscopy can be used to decrease the spectral overlap by encoding the phase evolution behaviour of coupled spin systems in second frequency dimension. At ultra-high fields typical localization schemes can often limit the minimum achievable echo times and therefor hampering the actual 2D experiment. To circumvent this problem SPECIAL was implemented on a Philips 7T system and j-resolved spectra were acquired in a phantom and a healthy volunteer. 931. Implementation and Validation of Localized Constant-Time PRESS on a 7T MRI/MRS Scanner Bhaskaran David Prakash1, Loyola D'Silva1, Kishore Bhakoo1, David Townsend1, S. Sendhil Velan1 1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore We have implemented and validated the LCT-PRESS technique in healthy rat brain. This sequence clearly demonstrates superior resolution and permits reliable detection of several brain metabolites that overlap in conventional techniques. The LCT-PRESS sequence performs this separation due to its incorporation of constant-time evolution, resulting in spin-spin decoupling along the F1 dimension. 932. The Benefits of Higher Order B0 Shimming of the Human Brain at 7T Hoby Patrick Hetherington1, Kai-Ming Lo2, William Punchard2, Piotr Starewicz2, Jullie W. Pan1 1Neurosurgery, Yale University, New Haven, CT, United States; 2Resonance Research Inc., Billerica, MA, United States With the advent of ultrahigh field systems, 7T, significant improvements in spectroscopic imaging studies of the human brain have been anticipated. However, these gains are dependent upon the achievable B0 homogeneity, both globally (over the entire ROI or slice) and locally (the linewidths of individual SI voxels within the ROI). Our 7T human brain data demonstrates that substantial improvements in both global and local homogeneity can be achieved using 1st-3rd and higher order shims. The required strengths to achieve higher order terms (4th and 5th orders) can be obtained using a shim insert and modest strength power supplies. 933. Early Metabolic Changes of Mild Traumatic Brain Injury Revealed by 3D MRSI at 3T Duan Xu1,2, Natalie Charlton1, Srivathsa Veeraraghavan1, Geoffrey T. Manley3, Pratik Mukherjee1,2 1Dept of Radiology, UCSF, San Francisco, CA, United States; 2UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco and Berkeley, CA, United States; 3Dept of Neurosurgery, UCSF, San Francisco, CA, United States Conventional MR imaging does not accurately predict outcome in mild TBI, but MR diffusion and proton spectroscopy has shown promise as potential biomarkers for injury severity and long-term neurocognitive and functional outcome. In this study, we utilized 3D MRSI at 3T with wide anatomic coverage to assess TBI in specific association, commissural, and projection white matter tracts. 934. Constant-TE Difference Editing of Serine at 3T: Simulation and Phantom Study Changho Choi1, Aditya Patel1 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States Serine (Ser) in human brain, which has coupled proton resonances at 3.98, 3.94, and 3.83 ppm, is difficult to measure because of its relatively low concentration (~0.5 mM) and the spectral overlap with the creatine (Cr) 3.92 ppm resonance. Constant-TE difference editing strategies for detection of Ser at 3T have been explored. Echo time dependence of the Ser multiplet was investigated, with density-matrix simulation, for point-resolved spectroscopy and triple refocusing. The Ser multiplets in sub- and difference-spectra were in good agreement between simulation and phantom experiments. In vivo feasibility of the difference editing methods is discussed with results from a phantom with physiological concentrations of Ser and Cr. Zenon Starcuk jr. 1, Zenon Starcuk1, Jana Starcukova1 1Magnetic Resonance & Bioinformatics, Institute of Scientific Instruments, Acad. Sci. Czech Rep., Brno, Czech Republic A short VAPOR-like water suppression sequence is presented, exhibiting similarly low B1 and T1 sensitivity and improved excitation profiles. The improvements are based on optimization of flip angles and pulse durations of chemical-shift selective pulses interleaved with fixed short delays. The sequence consists of 6-pulse water presaturation with asymmetric RF pulses, followed by B1-insensitive inversion and the localization module. The improved robustness may be utilized for an accurate control of residual water signal and exploiting it as a reference. Thanks to the reduced length and reduced impact on metabolites, the sequence should improve quantifiability and be suitable for spectroscopic imaging. Victor Rakesh Lazar1, David J. Manton2, Timo Schirmer3, Ralph Noeske3, Gary P. Liney4, Martin Lowry5, Mark Lorch6, Lindsay W. Turnbull5 1Centre for MR Investigations, University of Hull, Hull, North Humberside, United Kingdom; 2CMRI, University of Hull, Hull, United Kingdom; 3GE Healthcare; 4Radiotherapy Physics, Queen's Centre for Oncology, Hull, North Humberside, United Kingdom; 5CMRI, University of Hull, Hull, North Humberside, United Kingdom; 6Department of Chemistry, University of Hull, Hull, North Humberside, United Kingdom Water:lipid signal ratio (WLSR) can be measured with unsuppressed 1H MR spectroscopy and such data can be used to characterise breast cancer and bone disease. It is important, however, to be aware of potential bias (systematic errors) in these measurements as caused by chemical shift-induced voxel offsets which will be relatively large for the 3.4 p.p.m. water-lipid separation. Preliminary investigation and results related to this condition has been explained. Lisa Maria Harris1, Phil Dean1, Annette Sterr1 1Psychology, University of Surrey, Guildford, Surrey, United Kingdom Mild traumatic brain injury (mTBI) typically induces a set of symptoms, including poor memory, collectively referred to as Post Concussion Syndrome (PCS). A combination of a working memory task and magnetic resonance spectroscopy was used in a study to investigate the link between metabolite alterations, PCS symptoms and working memory ability in mTBI participants at least one year post injury. Lactate showed a significant positive correlation with PCS symptoms, this is usually elevated in the acute phase. There was also a trend towards high lipids and macromolecules in those with more PCS symptoms. Daniel Guo Quae Chong1, Jean-Marc Nuoffer2, Christine Sandra Bolliger1, Peter Vermathen1, Chris Boesch1, Roland Kreis1 1Department of Clinical Research, University Bern, Bern, Switzerland; 2Departement Hämatologie, Onkologie, Infektiologie, Labor-Medizin und Spitalpharmazie (DOLS), Inselspital, Bern, Switzerland Normal human blood and brain histidine concentrations were measured over a 10 hour period after an oral load. On average, blood histidine concentrations reached a maximum of 3.5 mM while brain histidine peaked at 1.9 mM, 5 hours after blood. Applying the symmetric Michaelis-Menten kinetics resulted in kinetic parameters of maximum transport of 23 nmol/g/min, an apparent Michaelis constant of 2.1 mM and a cerebral metabolization rate of 0.3 nmol/g/min. The complexity of the system investigated and various factors render the data inconclusive upon the appropriate kinetic model and potential subject dependence of the kinetics. Najib Allaļli1,2, Malgorzata Marjanska3, Edward J. Auerbach3, Eric Bardinet1, Philippe Fossati4, Romain Valabrčgue1, Stéphane Lehéricy1 1CRICM (CENIR), UPMC/INSERM UMRS 975/ CNRS UMR 7225, Hōpital Pitié-Salpźtričre, Paris, France; 2Centre Emotion CNRS USR 3246, Paris, France; 3Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States; 4Centre Emotion CNRS USR 3246, Hōpital Pitié-Salpźtričre, 47 bd de l'Hōpital 75013 Paris, France Scan to scan reproducibility is challenging, especially in the deep brain regions such as hippocampus where lower SNR and poor magnetic field homogeneity can lead to larger uncertainties in metabolite quantification. Few studies have investigated 1H-MRS reproducibility in the hippocampus either at low magnetic field strength or with few subjects. Relatively large VOI were used in most of these studies, resulting in partial volume effects. In this study, we investigated the reproducibility of spectroscopic measurements in the hippocampus at 3 tesla using a LASER sequence . We performed our measurements in a 2.4 mL volume to minimize partial volume effects. 940. Simultaneously Assessed GABA/Glutamate/Glutamine Concentration Gender Differences at 3.0T Peter Sheffield1,2, Michael D. Noseworthy, 2,3 1School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada; 2Brain-Body Institute, St. Joseph's Healthcare, Hamilton, ON, Canada; 3Electrical and Computer Engineering, School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada Herein we demonstrate the necessity for separating control subjects by gender when analyzing the metabolites of the GABA/glutamate/glutamine (Glx) spin system. Seven male and five female subjects were recruited to assess differences in these metabolites using a STEAM sequence optimized for Glx quantification. Results indicate that GABA concentrations in the anterior cingulate cortex of females are significantly lower than in males, in contrast to previous occipital GABA studies. Therefore, care must be taken when developing control groups for Glx metabolite analysis. Our results also illuminate a possible etiology for executive mood disorder obscured by previous reports. 941. Can You Really Use the Creatine Equilibrium to Calculate Free ADP Concentrations? Christine Nabuurs1, Cees Hilbers2, Arend Heerschap1 1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 2Laboratory of Physical Chemistry, Faculty of Science, Nijmegen, Netherlands 31P saturation transfer experiments in MAK=/= and WT muscle demonstrated a neglegible effect of CK and AK mediated enzymatic phosphoryl exchanges between ā-ADP and ā-ATP. These results are in conflict with the expected 65% reduction of ā-ATP upon saturation of the (ćATP/)ā-ADP resonance. Hence, the major ADP pool which is available to the CK reaction cannot be saturated. We propose a solid-state like ADP pool, which is in exchange with a transient ADP pool that associates with CK. The inability to saturate the āADP spin system challenges the validity of calculating the free ADP concentration from the CK equilibrium. 942. In Vivo GABA Measurement of Sensorimotor Cortex Pallab Bhattacharyya1, Micheal Phillips1, Lael Stone1, Mark Lowe1 1Cleveland Clinic, Cleveland, OH, United States Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the brain. Abnormal GABA has been implicated in several neuropsychiatric disorders. Using a variant of MEGA point resolved spectroscopy (MEGA-PRESS) sequence with interleaved water scans to detect subject motion, GABA level of sensorimotor cortex in healthy volunteers was measured, where the spectroscopy voxel was identified from a functional MRI scan. In addition, using linear regression analysis, GABA concentration in gray matter and white matter in the sensorimotor region were obtained.
943. Performance Analysis of the Two Spectroscopic Imaging Sequences LRE and EPSI Rudolf Fritz Fischer1, Kilian Weiss1, Christof Baltes1, Markus Rudin1, Peter Boesiger1, Sebastian Kozerke1 1Swiss Federal Institute of Technology and University Zurich, Zurich, Switzerland We compare the sensitivity of the two spectroscopic imaging sequences Echo Planar Spectroscopic Imaging (EPSI) and Linear Response Equilibrium (LRE), a steady state free precession sequence with intrinsic suppression of periodic bands. Simulations and phantom experiments were performed revealing a good SNR performance of LRE especially at low spectral bandwidth. 944. Accurate Brain Tumor Biopsy Using 3D 1H-MRS Neuronavigation Berkay Kanberoglu1, Josef P. Debbins2, Lina J. Karam1 1Electrical Engineering, Arizona State University, Tempe, AZ, United States; 2Keller Center for Imaging Innovation, Barrow Neurological Institute, Phoenix, AZ, United States To correlate the 3D H-MRS voxel spectra of tumors with genetic and ex-vivo NMR data, it is imperative that the biopsy of the tissue of interest be as accurate as possible. The goal of this work is to present a method to make biopsies more accurate by creating regions of intests (ROIs) from MRS data and overlaying them onto the structural datasets during the biopsy. The overlaid ROI masks illuminate the biopsy regions on the surgical navigation system and act as markers like the markers used in fMRI. 945. Open Coil Arrangement for Interventional Magnetic Particle Imaging Timo Frederik Sattel1, Tobias Knopp1, Sven Biederer1, Thorsten M. Buzug1 1Institute of Medical Engineering, University, Luebeck, Germany Magnetic particle imaging is a method capable of determining the spatial distribution of super-paramagnetic iron oxide particles. To obtain information about the particle distribution, a field-free point is steered on a trajectory through the field-of-view. For magnetic field generation and particle signal reception, electromagnetic coils are used. In their original paper, Gleich and Weizenecker proposed a tube-like scanner setup. In this contribution, a new coil geometry is introduced. It provides lateral access to the specimen and thus allows for interventional MPI. To prove feasibility, 2D FFP trajectories are simulated, which give promising results. 946. Reconstruction of Phase Rotation Spectroscopy Data on Partial Parallel Array MRI Systems Sarah Andrea Wijtenburg1,2, Jack Knight-Scott1 1Radiology, Children's Healthcare of Atlanta, Atlanta, GA, United States; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States Current algorithms for combining coil signals from partial parallel array MRI systems negate the effects of the phase rotation technique in 1H-MRS. Here, we present an altered processing method to overcome these challenges. 947. A New Detection Scheme for Ultrafast 2D COSY Shuhui Cai1, Mingfang Zhao1, Zhong Chen1 1Department of Physics, Xiamen University, Xiamen, Fujian, China Two-dimensional NMR techniques greatly extend the application fields of NMR spectroscopy. Unfortunately, the collection of numerous t1 increments leads 2D experiments fairly time-consuming. The spatial encoding ultrafast technique enables fast acquisition of 2D NMR spectra. In this abstract, a new ultrafast 2D COSY method based on continuous constant-time phase-modulated spatial encoding was proposed. Compared to the previous real-time phase-modulated method, the present method not only gives much better spectral signal-to-noise ratio and resolution, but also is much easier to implement. Wen Zhang1, Shuhui Cai1, Zhong Chen1 1Department of Physics, Xiamen University, Xiamen, Fujian, China The intermolecular multiple-quantum coherence (iMQC) signals between 1H (spin-1/2) and 23Na (spin-3/2) nuclei were studied theoretically and experimentally using the CRAZED pulse sequence. The results show that no matter which spin is detected, the dependences of the iMQC signal intensities on the RF pulse flip angles follow the same rules and are identical to those for other heteronuclear systems, implying that heteronuclear iMQCs have same properties in liquid NMR. 949. Removal of FM Sidebands Artifacts in NWS MRS by QZ-Bac Algorithm Jyh-Miin Lin1, Hsiao-Wen Chung2, Shang-Yueh Tsai3 1Department of Radiology, Mackay Memorial Hospital, Taipei, Taiwan; 2Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan; 3Department of Electrical Engineering, Chang Gung University, Tao Yuan, Taiwan 1H non-water suppressed(NWS) MRS is a developing technique to in vivo metabolites concentration, with high accuracy than conventional water suppressed(WS) MRS. In NWS MRS, complete removal of water signal is critical for quantifying metabolites concentration. We propose a novel postacqusitional (QZ-bac) algorithm to eliminate water peaks and water related sidebands. With this method, the water related frequency modulation signals were completely removed by exploiting the antisymmetry property. Computer simulations and in vivo demonstration were shown. 950. High Precision Calibration of MRS Thermometry Using Validated Temperature Standards Elena Vescovo1, Andrew Levick2, Sha Zhao1, Graham Machin2, Charmaine Childs3, Timothy Rainey3, Steve Williams1 1Imaging Science and Biomedical Engineering, The University of Manchester, Manchester, Greater Manchester, United Kingdom; 2Temperature Group, National Physical Laboratory, Teddington, Middlesex, United Kingdom; 3Brain Injury Research Group, The University of Manchester, Manchester, Greater Manchester, United Kingdom Estimation of temperature by MRS from the chemical shift of water relative to N-acetylaspartate (NAA) relies on a calibration curve. To date these have never been related back to primary standards. We describe extremely stable temperature control of an MRS phantom at 1.5T using a circulating water bath and organic fixed-point materials, with measurements related back to the International Temperature Scale 1990 (ITS-90) at the UK National Physical Laboratory. Frequency differences (water-NAA) were highly reproducible (SD<10-4 ppm) at fixed temperature and R2 for the fit was 0.9996. Ionic strength affected the intercept but not slope of the temperature calibration. 951. In Vivo Temperature Brain Map Using Jmrui V4.X: A Plugin Development Elena Vescovo1, Federico Di Cesare2, Dan Stefan2, Danielle Graveron-Demilly2, Steve Williams3 1Image Science and Biomedical Engineering,, The University of Manchester, Manchester, Greater Manchester, United Kingdom; 2Laboratoire CREATIS-LRMN, CNRS UMR 5220, Universite' Claude Bernard Lyon 1, Lyon, France; 3Image Science and Biomedical Engineering, The University of Manchester, Manchester, Greater Manchester, United Kingdom Magnetic resonance spectroscopy can provide a non-invasive approach to measure the internal temperature of the brain; it relies on the linear relationship between the 1H MR resonance frequency of water in the tissue and the tissues temperature. The absolute temperature is obtained by measuring the chemical shift of water relative to a reference compound such as N-Acetylaspartate (NAA). To convert the frequency difference between these two signals into temperature, it is necessary to apply a calibration curve. All these procedures could be performed using a plugin of jMRUI, a Java-based Graphical User Interface that allows time-domains analysis of MRS, MRSI and HRMS-NMR signals. In this work we used jMRUI v4.x, a new version of the software that enabled the user to add their own plugin.
952. Efficient Generation of a Magnetic Field-Free Line Tobias Knopp1, Marlitt Erbe1, Timo F. Sattel1, Sven Biederer1, Thorsten M. Buzug1 1Institute of Medical Engineering, University of Lübeck, Lübeck, Germany Spatial encoding in magnetic particle imaging (MPI) is achieved by moving a field-free point (FFP) through the imaging volume. Recently, it was shown that the sensitivity of MPI can be increased by taking advantage of a field-free line (FFL) for spatial encoding. However, until today the power loss of an FFL scanner was thousand times higher than the power loss of an FFP scanner. In this work, the first feasible coil setup is presented, which has a power loss of the same order as an FFP scanner. 953. Relaxation Enhancement by Longitudinal Multispin Orders Loyola D'Silva1, S. Sendhil Velan1 1Laboratory for Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore There is a great interest in increasing the longitudinal relaxation of nuclear spins for hyperpolarized imaging experiments. Longitudinal multispin orders (LOMO) correspond to the non-equilibrium population distribution and can be created in spin systems that exhibit J couplings, dipolar couplings or quadrupolar couplings. It can also be created via cross-correlated relaxation between different relaxation pathways present for the given spin system. A two fold increase in longitudinal magnetization is achieved using the frequency cycling approach. Sven Biederer1, Tobias Knopp1, Timo Frederik Sattel1, Marlitt Erbe1, Thorsten M. Buzug1 1Institute of Medical Engineering, University of Luebeck, Luebeck, Germany In Magnetic Particle Imaging the iron-core size distribution is a very important criterion for the imaging quality as well as for a model based reconstruction. An estimation of such a distribution is possible by using magnetization spectra of a Magnetic Particle Spectrometer. In this contribution a method is presented to improve the condition of the minimization problem. For this purpose offset fields are added to the sinusoidal excitation of the Magnetic Particle Spectrometer. This leads to a more stable and robust estimation of the iron-core size distribution. Hadassah Shinar1, Tal Ben -David1, Uzi Eliav1, Gil Navon1 1School of Chemistry, Tel Aviv University, Tel Aviv, Israel 2H double quantum filtered (DQF) NMR of nerves and spinal cords enabled the assignment of the different signals to their anatomical compartments. In nerves the signals with the quadrupolar splittings of approximately 1500, 500, and 200 Hz were assigned to the water in the epineurium, myelin sheaths and endoneurium respectively. A narrow signal was also observed and assigned to intraaxonal water. In spinal cords only the 500 Hz satellites and the narrow signal were detected. The assignment was based on a series of experiments including the effects of collagenase, stretching, Wallerian degeneration, diffusion and was corroborated by histology. < Alexander Gussew1, Reinhard Rzanny1, Hans Christoph Scholle2, Juergen R. Reichenbach1 1Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital, Jena, Germany; 2Division Motor Research, Pathophysiology and Biomechanics, Department of Trauma, Hand and Reconstruc, Jena University Hospital, Jena, Germany In vivo 1H-MRS detection of metabolic changes associated with chronic pain may provide deeper understanding of biochemical neuronal dysfunctions caused by chronification and may potentially help to specify therapeutic approaches. In this study absolute concentrations of metabolites N-acetyl aspartate, creatine, total choline, myo-Inositol and glutamate were measured by single voxel 1H-MRS at 3 T in anterior insular, anterior cingulate cortex and thalamus of six patients with chronic low back pain and corresponding healthy controls. In all investigated brain regions, concentration decrease of all metabolites up to 36% was observed in patients. Spectroscopy Localization & Imaging Methodology Hall B Monday 14:00-16:00 Toru Shirai1, Satoshi Hirata1, Yoshitaka Bito1 1Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo, Japan We have developed a technique for simultaneously acquiring of metabolite and water signals in 3D echo planar spectroscopic imaging (EPSI). The pulse sequence of this technique includes three CHESS pulses the amplitude of which is switched alternately in accordance with slice encoding steps to reverse the polarity of the water signal. The metabolite signal is separable from the water signal, because the water signal is shifted to the top and bottom of the reconstructed 3D image. The results of phantom experiments showed that this technique effectively corrected the eddy current influence, suggesting the usefulness of the proposed method. 958. Accelerated Reconstruction Using Parallel Computing for Spiral Spectroscopic Imaging Dong-Hyun Kim1, Yoon-Ho Oh1, Yoon-Ho Nam1, Meng Gu2, Won-Woo Ro1 1Electrical and Electronic Engineering, Yonsei University, Seoul, Korea, Republic of; 2Radiology, Stanford University, Stanford, United States Fast spectroscopic imaging such as spiral CSI can be used for applications such as real time metabolite imaging or real time temperature mapping. While methods to reduce the data acquisition time have been continuously developed, reconstruction times have been prolonged. We demonstrate the usage of parallel computing to reduce the reconstruction time of spiral CSI. By using a multi-threading approach, reconstruction times during the gridding routine can be shortened to by a factor of eight. 959. Water Suppression for Diffusion-Weighted Line-Scan Echo-Planar Spectroscopic Imaging Yoshitaka Bito1, Koji Hirata1, Toshihiko Ebisu2, Yuko Kawai3, Yosuke Otake1, Satoshi Hirata1, Toru Shirai1, Yoshihisa Soutome1, Hisaaki Ochi1, Masahiro Umeda3, Toshihiro Higuchi4, Chuzo Tanaka4 1Central Research Laboratory, Hitachi, Ltd., Kokubunji-shi, Tokyo, Japan; 2Neurosurgery, Nantan General Hospital, Nantan-shi, Kyoto, Japan; 3Medical Informatics, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan; 4Neurosurgery, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan A water suppression (WS) technique for diffusion-weighted line-scan echo-planar spectroscopic imaging (DW-LSEPSI) is presented. DW-LSEPSI uses a single chemical shift selective (CHESS) pulse for WS at each acquisition of a line suitable for a short acquisition time and to reduce a water signal using a steady state effect. The signal attenuation of the water signal is numerically analyzed and demonstrated by applying this technique to phantoms and a rat brain in vivo. Chin-Yu Lu1, Yi-Ru Lin2, Stefan Posse3,4, Shang-Yueh Tsai5 1Biomedical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; 2Eletronic Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; 3Department of Neurology, University of New Mexico School of Medicine, Albuquerque, Albuquerque, New Mexico 87131, United States; 4Electrical and Computer Engineering Department, University of New Mexico, Albuquerque, NM, United States; 5Electrical Engineering, Chang Gung University, Taoyuan, Taiwan Previous dsrPEPSI study which measured glutamate (Glu) shown the feasibility to reduce scan time from 16 mins to 1min. However, as scan time reduced, the SNR decreased and poor spectra qualities were observed. This study conducted to investigate and optimize the spectra quality versus scan time by tuning the arrangement of radial trajectories and TEs. From our result, 4-fold dsrPEPSI is feasible to acquire Glu at a 3T system while maintaining spectral quality. And the scan time was 4 minutes, which was a reasonable length for clinical use. 961. High-Speed GABA Mapping in Human Brain with MEGA-PEPSI at 3 Tesla Ulrike Dydak1,2, Malgorzata Marjanska3, Stefan Posse4,5 1School of Health Sciences, Purdue University, West Lafayette, IN, United States; 2Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States; 3Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States; 4Department of Neurology, University of New Mexico School of Medicine, Albuquerque, NM, United States; 5Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, United States The feasibility of GABA-edited magnetic resonance spectroscopic imaging with short scan times is demonstrated both in a phantom and in vivo by combining the high-speed (Proton-Echo-Planar-Spectroscopic-Imaging) PEPSI sequence with the MEGA editing scheme. We show MEGA-PEPSI spectra from an axial slice in the human brain acquired at 3 T within < 5 min with a nominal resolution of 8 ml. The signal of GABA and co-edited macromolecules is clearly discernable in most spectra and was fitted with LCModel, using a simulated basis for this sequence. Spectral fitting of the GABA resonance was feasible with Cramer Rao lower bounds < 20 %. Yoshitaka Bito1, Koji Hirata1, Satoshi Hirata1, Toru Shirai1, Toshihiko Ebisu2, Yuko Kawai3, Yosuke Otake1, Yoshihisa Soutome1, Hisaaki Ochi1, Masahiro Umeda3, Toshihiro Higuchi4, Chuzo Tanaka4 1Central Research Laboratory, Hitachi, Ltd., Kokubunji-shi, Tokyo, Japan; 2Neurosurgery, Nantan General Hospital, Nantan-shi, Kyoto, Japan; 3Medical Informatics, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan; 4Neurosurgery, Meiji University of Integrative Medicine, Nantan-shi, Kyoto, Japan High-speed spectroscopic imaging using the echo-planar technique is sometimes distorted by eddy currents. We developed an eddy current correction technique for time-domain-interleaved blipped-phase-encoding echo-planar spectroscopic imaging (TDI-BPE-EPSI). This technique uses correction of spatial shift due to chemical shifts in the blipped-phase-encoding direction before applying eddy current correction based on the water signal. Correction of eddy currents is demonstrated by applying this technique to a phantom and a rat brain in vivo. This technique is shown to be also useful in diffusion-weighted spectroscopic imaging, which causes more eddy currents due to strong diffusion gradients. 963. Comparison of Automatic and Manual Prescription Protocols for Brain 3D MRSI Eugene Ozhinsky1,2, Daniel B. Vigneron1,3, Susan M. Chang4, Sarah J. Nelson1,3 1Surbeck Laboratory of Advanced Imaging, Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2UCSF/UCB Joint Graduate Group in Bioengineering, University of California, San Francisco, San Francisco, CA, United States; 3Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, United States; 4Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States In this work we have evaluated the coverage volume and data quality of 3D MRSI protocols with manual and automatic prescription of outer-volume suppression and selected volume. Automatic oblique prescription allowed approximately 3x increase in coverage volume with no decline in data quality. 964. Inductively Coupled Reference Signal Injection Method for Quantitative MRI Donghoon Lee1, Kenneth Marro1, Mark Mathis1, Cecil Hayes1 1University of Washington, Seattle, WA, United States We report our efforts on continuous development of a synthetic signal injection method for metabolite quantification using MRS and MRI. This work demonstrates that calibrated synthetic voxels (instead of pseudo-FID: free induction decay), injected during or separately from real image acquisition, can be used to quantify metabolite content in real 19F image voxels. Images of vials containing different concentrations of sodium fluoride (NaF) were converted to units of moles by reference to precalibrated synthetically-injected voxels. Additional images of vials containing variable sodium chloride (NaCl) demonstrate that the quantification process is robust and immune to changes in coil loading conditions. 965. Iterative CSI Reconstruction with High-Resoluiton Spatial Priors for Improved Lipid Suppression Joonsung Lee1, Elfar Adalsteinsson1,2 1Electrical engineering and computer science, Massachusetts Institute of Technology, Cambridge, MA, United States; 2Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States We have developed and demonstrated an iterative reconstruction with spatial priors for improved lipid suppression. By imposing the spatial locality constraint on the lipid spectra inside the brain, we are able to substantially improve lipid suppression from the subcutaneous fat into the brain. 966. Skewed Adiabatic Pulses for Outer Volume Suppression in Single Voxel Spectroscopy Federico Giove1,2, Francesco Marcocci1, Fabrizio Fasano, 1,3, Mauro DiNuzzo1, Gisela E. Hagberg3, Bruno Maraviglia1,2 1Department of Physics, Sapienza University of Rome, Rome, RM, Italy; 2MARBILab, Enrico Fermi Center, Rome, RM, Italy; 3Neuroimaging Laboratory, Fondazione Santa Lucia IRCCS, Rome, RM, Italy We developed an outer volume suppression approach for nulling the external signal in single voxel spectroscopy, based on trains of adiabatitic skewed selective pulse. The pulses shape allowed the saturation bands to be prescribed adjacent to the voxel, without loss of signal. The train was tested before STEAM and PRESS acquisition schemes at 3T, and showed excellent performaces both in vitro and in vivo, in particolar for the suppression of exravoxel lipids in the visual cortex. Optimal performances were observed with VAPOR water suppression and short TE STEAM, but the approach worked eqaully well before PRESS at intermediate (30ms) TE Kaung-Ti Yung1, Chenguang Zhao1, Weili Zheng1, Manel Martinez-Ramon2, Andre van der Kouwe3, Stefan Posse1,4 1Neurology, University of New Mexico School of Medicine, Albuquerque, NM, United States; 2Dept. of Signal Processing and Communications, Universidad Carlos III de Madrid, Madrid, Spain; 3Radiology, Massachusetts General Hospital, Boston, MA, United States; 4Electrical and Computer Engineering, University of New Mexico, Albuquerque, NM, United States Manual placement of outer volume suppression (OVS) slices in short TE proton MR spectroscopic imaging (MRSI) is time consuming and prone to human error. Here, we introduce an atlas-based approach to optimally positions both the 3D MRSI slab and up to 16 OVS slices in a subjects head using affine transformation of MRSI slab and OVS slice positions that are optimally placed in MNI space. In vivo 3D short TE (11 ms) Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI) demonstrates consistent spectral quality with the MRSI volume and comparable lipid suppression for automatic and manual OVS placement, which is desirable for clinical research studies. 968. Targeted Fat Characterization with MQC Pathways Gigi Galiana1, Robert Todd Constable1 1Diagnostic Radiology, Yale University, New Haven, CT, United States We report a method to quantify and characterize lipids in vivo. The method can generate simultaneous maps of saturated lipid, unsaturated lipid, and water, or it can also be run as a spectroscopic sequence to generate high resolution and very edited spectra. We present results from both implementations and show that the method can be used to discriminate lipids that are indistinguishable by other means. 969. Exotic Phase Cycling in 1H MRS Sarah Andrea Wijtenburg1,2, Jack Knight-Scott1 1Radiology, Children's Healthcare of Atlanta, Atlanta, GA, United States; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States Exotic phase cycling refers to utilizing more complex phase cycling schemes to eliminate signals from unwanted coherence pathways. Here, we outline the general steps for designing an exotic phase cycle. Yao Fu1,2, Hacene Serrai1 1National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; 2Electrical and Computer Engineering, University of Manitoba, Winnipeg, Manitoba, Canada We here report our recent phantom results using wavelet encoding (WE) combined with parallel imaging (PI, WE-PI) to acquire 1D magnetic resonance spectroscopic imaging (MRSI). Two sets of experiments are performed with the same acceleration factor (R = 2) and two different resolutions (N = 4 and N = 8). The results confirm that WE-PI reduces further the acquisition time by approximately the acceleration factor R, and preserves the spatial metabolite distribution with minimal loss of the signal-to-noise ratio (SNR) as compared to the WE-SI technique. Yao Fu1,2, Hacene Serrai1 1National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; 2Electrical and Computer Engineering, University of Manitoba, Winnipeg, Manitoba, Canada We present our first in vivo results demonstrating wavelet encoded 3D spectroscopic imaging (WE-SI) at high magnetic field (3T) compared with standard, Fourier-encoded, chemical shift imaging (CSI). As previously demonstrated with phantom results, we confirm a reduction in acquisition time and pixel bleed for equivalent number of encodes as compared to CSI, with the predicted drop in SNR. In-vivo results show that WE-SI preserves metabolite signal distributions while reducing acquisition time, demonstrating that WE-SI is providing accurate MRSI results with higher sensitivity at higher fields. 972. Trapzoidal Volume Selection Using Adiabatic Pulses Bu S. Park1, Jun Shen1 1National Institute of Mental Health (NIMH), National Institute of Health (NIH), Bethesda, MD, United States Because of high immunity to RF inhomogeneity and excellent slice profiles, adiabatic pulses are widely used for special localization in MR spectroscopy. Here we propose a scheme for selecting a trapezoidal volume using adiabatic š pulses since non-rectangular volume is often preferred in localized spectroscopy. In this scheme, a time-varying gradient orthogonal to a stationary slice-selection gradient is used to change the initial and final boundaries of the slice profile from parallel to non-parallel. 973. SAR-Reduced Spectroscopic FAST Imaging with Variable Flip Angles Linda Becker1, Wolfgang Dreher1, Dieter Leibfritz1 1Dept. Chemistry, University of Bremen, Bremen, Germany A variation of the SSFP-based fast spectroscopic imaging technique spFAST is presented. By flip angle variation the specific absorption rate (SAR) can be reduced considerably with only a minor loss in the signal-to-noise ratio (depending on the relaxation times). Additionally, the oscillating signal intensities can be exploited for k-space weighting in one spatial phase encoding direction which enables better spatial localization. Simulations and experiments at 7T showed that a gaussian flip angle series offers good results for all tested relaxation times. 974. Neurochemical Profiles of Several Brain Regions Determined by Short-Echo, 1H MRS at 7T Uzay Emrah Emir1, Melissa Terpstra1, Ivan Tkac1, Gulin Oz1 1University of Minnesota, Minneapolis, MN, United States All studies that obtained a neurochemical profile from short echo 1H MRS at 7T so far utilized data from the occipital lobe acquired with surface coils. In this study, we demonstrate the feasibility of acquiring and quantifying short-echo (TE = 8 ms), single voxel STEAM spectra by utilizing 16 channel transmit/receive transmission line coils and B1 shimming at 7T. Representative spectra and neurochemical profiles are reported from brain regions that are of interest for various neurological disorders, such as the frontal white matter, posterior cingulate, putamen, and the substantia nigra. Xavier Tizon1, Peggy Provent1, Sebastien Parfait2, Gilles Crehange3, Johel Miteran2, Philippe Genne1, FranƧois Brunotte2, Olivier Duchamp1, Paul Michael Walker2 1Oncodesign, Dijon, France; 2Laboratoire Le2i - UMR CNRS 5158, Dijon, France; 3Centre Georges-Francois Leclerc, Dijon, France 1H-MRS appears to be a sensitive technique to detect prostate cancer in the clinic. The aim of this study was to establish an experimental setting to monitor the metabolism of orthotopic prostate cancer in rats, as a candidate biomarker of efficacy for anticancer drugs. The metabolism of healthy prostates and orthotopic PC3-MM2 tumor models was monitored by 1H-MRS on Nude rats. Despite the highlighted differences between human and rat prostate metabolism, we show that the follow-up of prostate tumor metabolism in rats is possible and that the tumor metabolism is different from its host gland. Grzegorz Lukasz Chadzynski1, Adriane Groeger2, Uwe Klose3 1Department for Diagnostic and Interventional Neuroradiology, University Hospital Tuebingen, Tuebingen, Baden- Wuerttemberg, Germany; 2Department of Neurodegeneration, Hertie Institute for Clinical Brain Research, Tuebingen, Baden-Wuertemberg, Germany; 3Department for Diagnostic and Interventional Neuroradiology, University Hospital Tuebingen, Tuebingen, Baden-Wuertemberg, Germany Recent studies showed that the frequency distance between water and NAA measured with 1HMRS may be used for temperature evaluation. We examined regional difference of this distance in the human brain at the level of the lateral ventricles. CSI measurement were performed for 11 healthy volunteers. Spectra were acquired at 3T with PRESS localization without water suppression. We found water to NAA frequency distance to be greater in white than in gray matter with mean difference value of 0.013 ppm. According to the literature this would be approximately equal to 1oC. More reliable results can be obtained after calibration measurements. Yan Zhang1, Jun Shen1 1National Institute of Mental Health, Bethesda, MD, United States This work demonstrates the use of an optimized RF frequency offset for the point resolved spectroscopy (PRESS) in measurement of Lactate. The partially refocused methine proton spins due to limited RF bandwidth give rise to anomalous J-modulation for methyl proton spins, resulting in signal cancellation. With the offset of 4.1ppm, all selected methine proton spins are on resonance, and therefore no methyl proton spins are anomalously modulated, except there is a portion of the methyl proton spins are outside the RF bandwidth due to the chemical shift. But this part of methyl proton spins are to be saturated by the out volume suppression. The phantom experiment shows the net signal (ratio to NAA at 2 ppm) is enhanced by ~50% compared with that using the offset at 1.3ppm. 978. Feedback-Based Interleaved Reference Spectroscopy Thomas Lange1, Martin Buechert1, Maxim Zaitsev1 1Dept. of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany Magnetic resonance spectroscopy experiments can be severely affected by frequency drifts, for example when a spectroscopy scan is run right after an imaging experiment involving a high gradient duty cycle. In this work we propose a feedback-based interleaved reference scan (IRS) method which updates the carrier frequency of RF pulses and ADCs in real time, using water reference spectra acquired in an interleaved fashion. Compared to a frequency lock using the residual water peak in the actual spectrum, the proposed method is more robust, particularly in the presence of strong lipid contamination. Additionally, it allows for retrospective phase correction. 979. Highly Efficient Square Wave Distant Dipolar Field and Its Applications for in Vivo MRI Zhong Chen1, Congbo Cai1, Shuhui Cai1, Jianhui Zhong2 1Departments of Physics and Communication Engineering, Fujian Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, Fujian, China; 2Departments of Radiology and Biomedical Engineering, University of Rochester, Rochester, NY, United States The iMQC signal intensity can be enhanced by replacing the conventional sinusoidal distant dipolar field (DDF) with square wave DDF. In this abstract, instead of a series of adiabatic inversion pulses proposed previously, a more efficient composite adiabatic inversion pulse was applied to create square wave DDF. The square wave DDF was applied to MR imaging for the first time. The experimental results show that using the proposed square wave DDF in the ZEBRA sequence can enhance the iMQC signal intensity by about 1.5 times in comparison to the conventional CRAZED sequence. Non-Proton MRI Hall B Tuesday 13:30-15:30 Aiming Lu1, Ian C. Atkinson1, Xiaohong Joe Zhou1,2, Keith R. Thulborn1 1Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States; 2Departments of Neurosurgery, Radiology, and Bioengineering, University of Illinois at Chicago, Chicago, IL, United States Phosphocreatine (PCr) concentration can provide vital bioenergetic information in brain. Due to their low detection sensitivity, 31P MR signals are often detected with MRS or CSI approaches, which are either time consuming or spatial resolution limited. In this work, we report initial 31P imaging results using a spectral selective twisted projection imaging (TPI) sequence to achieve high data acquisition efficiency on a 9.4T human scanner. PCr and γ-ATP images were simultaneously obtained with whole brain coverage and reasonable SNR, temporal and spatial resolution. The ratio of the two resonances images can potentially allow detection of variation in PCr concentration. 981. In Vivo Chlorine-35, Sodium-23 and Proton Magnetic Resonance Imaging of the Rat Brain Stefan Kirsch1, Mark Augath2, David Seiffge3, Lothar Schilling3, Lothar Rudi Schad1 1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany; 2Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany; 3Division of Neurosurgical Research, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany In this study we demonstrate the feasibility of combined chlorine-35, sodium-23 and proton magnetic resonance imaging (MRI) at 9.4 Tesla and, to the best of our knowledge, present the first in vivo chlorine-35 images obtained by means of MRI. With the experimental setup all measurements could be done in one session without changing the setup or moving the subject. Multinuclear MR images were acquired from a healthy rat and from a rat displaying a focal cerebral infarction. Combined in vivo chlorine-35, sodium-23 and proton MRI may provide a new approach to study diseases which involve changes in the concentration of chloride or sodium ions. Jochen Keupp1, Samuel A. Wickline2, Gregory M. Lanza2, Shelton D. Caruthers2 1Philips Research Europe, Hamburg, Germany; 2C-TRAIN, Washington University, St. Louis, MO, United States 19F-MRI allows the direct quantification of nanoparticles (NP) or fluorinated drugs in molecular imaging. Previously, α ν β 3-integrin targeted NP have been shown to detect and quantify angiogenesis in tumor models. Towards human translation, clinically-relevant NP-substrates like perfluoro-octyl-bromide (PFOB) should be applied, but rich spectra and large chemical shifts (CS) add significant complexity. Many methods have been developed to manage CS-artifacts, but tradeoffs like long encoding time or a need for complex corrections remain. Herein, Hadamard-type pulse phase encoding is introduced in the CS domain as a robust and efficient method to detect multi-resonant 19F labels. Feasibility is demonstrated in vitro and in vivo for angiogenesis-targeted PFOB-NP in Vx2 tumor bearing rabbits. 983. Sodium Boost SPRITE Imaging of the Human Brain Sandro Romanzetti1, Eberhard D. Pracht1, N. Jon Shah1,2 1Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Forschungszentrum Juelich, Juelich, Germany; 2Faculty of Medicine, Department of Neurology, RWTH Aachen, Aachen, Germany Imaging of nuclei such as 23Na, 31P, and 17O is becoming very important to understand the physiology of the cell. However, due to the low concentration and short relaxation times of theses nuclei in tissues, dedicated sequences and high optimisation are required. The SPRITE sequence has shown its ability to image the sodium in the in vivo human brain at ultrashort encoding times. In this work, a novel way to improve the sensitivity of the standard SPRITE sequence by a factor 2 is presented. This is of particular relevance for all applications where the SNR is very low. Jacob Wheatley Myerson1, Li He2, Douglas M. Tollefsen2, Samuel A. Wickline1,2 1Biomedical Engineering, Washington University, Saint Louis, MO, United States; 2Department of Medicine, Washington University, United States Perfluorocarbon nanoparticles were functionalized with the direct thrombin inhibitor PPACK. PPACK nanoparticles outperformed heparin in stopping acute thrombosis in mice. The particles had high affinity and specificity for thrombin and were visible with 19F magnetic resonance spectroscopy and imaging. PPACK nanoparticles are proposed a first-in-class anticoagulant with intrinsic magnetic resonance contrast, concentrated therapeutic impact defined by a thrombin-absorbing particle surface, and pharmacokinetics optimized by the base particle. Ian C. Atkinson1, Aiming Lu1, Keith R. Thulborn1 1Center for MR Research, University of Illinois- Chicago, Chicago, IL, United States Quantitative sodium MR imaging predicts tissue viability and may offer information about diseases that disrupt tissue sodium ion homeostasis. The series of acquisitions necessary for computing the tissue sodium concentration bioscale from quantitative sodium MR imaging data often requires up to 30 minutes of human scanning and 30 minutes of phantom scanning. A new TPI-based technique is proposed that allows for rapid quantitative sodium MR imaging. Fast quantitative sodium imaging using this new data acquisition scheme that saves 20-40% of the total acquisition time is demonstrated in the human brain at 9.4 Tesla. 986. Fast 31P Metabolic Imaging of Human Muscle Isabell Kristin Steinseifer1, Jannie Petra Wijnen1, Bob Christian Hamans1, Arend Heerschap1, Tom Wilhelmus Scheenen1,2 1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany We present a 31P MRI technique to obtain images of PCr and β-ATP simultaneously by excitation of these resonances with a dual frequency selective Shinnar-LeRoux pulse at 7T. With proper choice of bandwidth of the 3D gradient echo imaging technique the chemical shift difference between the two resonances was used to completely separate images of the resonances within one large field of view. The concept of fast 31P metabolic imaging can also be applied to the brain, and even further expanded to other MR-detectable nuclei. Mikayel Dabaghyan1, Isabel Maria Dregely2, Iga Muradyan1, Mirko I. Hrovat3, Hiroto Hatabu1, James P. Butler4, Samuel Patz1 1Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States; 2Department of Physics, University of New Hampshire, Durham, NH, United States; 3Mirtech, Inc, Brockton, MA, United States; 4Department of Environmental Health, Harvard School of Public Health, Boston, MA, United States In this study we measured the regional partial pressure of oxygen in human lungs, using hyperpolarized xenon, whose signal depends on the presence of oxygens paramagnetic molecules. Similar studies have been conducted in the past using HP helium. A number of images was acquired and the evolution of the signal in each pixel was fit to a model describing its decay with time, taking into account the longitudinal relaxation time (T1), which is affected by the partial pressure of oxygen. Other parameters obtained from fitting the data to the model were the oxygen uptake rate RO2 and the flip angle for each pixel. Ileana Hancu1, Keith Park1, Randy Giaquinto1 1GE Global Research Center, Niskayuna, NY, United States Fluorine MRI is becoming a powerful tool for studying drug distribution and metabolism. For such studies, transmit/receive RF structures, capable of providing anatomical information at the 1H frequency and drug distribution/metabolism at the 19F frequency are needed. Past approaches for accomplishing this purposes include coil swapping or dual tuned coils. From difficult repositioning logistics, difficult construction, or SNR loses, none such methods has proven ideal. A very simple and efficient RF structure (a solenoid coupled to a loop) is presented in this work, which can operate at both frequencies of interest through a simple opening/closing of a mechanical/electrical switch. Jaime Mata1, Kai Ruppert1, Isabel Dregely2, Talissa Altes1, G. Wilson Miller1, Peter Sylvester1, Stephen Ketel3, Jeff Ketel3, Iulian Ruset3, F. William Hersman3, Klaus Hagspiel1, James Brookeman1, John Mugler III1 1University of Virginia, Charlottesville, VA, United States; 2University of New Hampshire, Durham, NH, United States; 3Xemed, LLC, Durham, NH, United States We report the preliminary evaluation of an optimized 2D-CSI and 3D-CSI technique with hyperpolarized Xe-129, using a rabbit model of lung fibrosis and another of emphysema. We report also for the first time, the acquisition of multiple contiguous slices images with a 3D-CSI version, that covers the entire lung in ~15s. From the CSI data, we directly calculate images reflecting the amount of Xe-129 in the airspaces, and dissolved in the lung tissue, blood, and other compartments thus obtain detailed spatial information regarding how Xe-129 is distributed in those different compartments, providing regional information about lung physiology. High-resolution 2D-CSI maps of the animal in the lung fibrosis group, show the presence of a third dissolved-phase chemical shift peak at around 185ppm from the alveolar gas peak, and adjacent to the dissolved-phase tissue peak. Quantification of the CSI maps for the animal in the fibrosis model group, show an almost two fold increase in the normalized tissue and blood peaks (tissue/gas and blood/gas). Maps of the 2D-CSI acquisitions for each one of the resolved peaks show that blood and tissue lung maps are identically spatially distributed at 1.5Tesla, perhaps due to signal contamination from their very close spectral proximity at this magnetic field. 2D and 3D-CSI acquisitions at magnetic fields higher than 1.5T should create a larger separation of the chemical shift peaks for each lung compartment and produce more detailed anatomical and physiological information. The single breath-hold 3D-CSI maps presented in here, show a promising development of this technique. 990. Drug Distribution Imaging of Anticancer Drug 5-FU Using 19F/1H Double-Tuned RF Coil Yosuke Otake1, Koji Hirata1, Yoshihisa Soutome1, Yoshitaka Bito1 1Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo, Japan Imaging of 19F-labeled drug distribution was demonstrated using a developed 19F/1H double-tuned RF coil and anticancer drug 5-FU administered rats. Fast spin echo with frequency selective pulses was used to efficiently obtain distribution images of 5-FU, its active anabolites, and its catabolites at the same time. The spatial change in signal intensity among several organs and tissue in images may be used to analyze the pharmacokinetics. The developed double-tuned RF coil will be a powerful tool for 19F-labeled compounds distribution imaging and pharmacokinetics research. 991. In Vivo Triple-Quantum (TQ) Sodium MRI on the Human Brain: SNR Benefits at 7T Yongxian Qian1, Fernando E. Boada1 1MR Research Center, Radiology, University of Pittsburgh, Pittsburgh, PA, United States Triple quantum (TQ) sodium imaging is an effective means decreasing the contribution from the intracellular and fluid spaces to the sodium (23Na) signal. The sodium TQ signal is, however, much weaker than the single quantum (SQ, or total tissue) signal (~1/10). In this study, we evaluate the SNR performance of TQ sodium MRI of the human brain at both 7T and 3T. Our results demonstrate that the theoretical SNR gains of 7T have tremendous benefits for TQ sodium MRI. 992. Single - Channel Multi - Coil Array Iga Muradyan1, Feng Zhou2, Pooja Soni2, Mikayel Dabaghyan1, Samuel Patz1, Mirko I. Hrovat3 1Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States; 2University of Massachusetts, Lowell; 3Mirtech, Inc, Brockton, MA, United States Here we report on a design and initial tests of a single-channel multi-coil array. As the name of the array suggests, this system will provide an efficient and simple way of using multiple coils on a single channel scanner. This has a significant cost advantage over multi-transmit channels. SCMC arrays would be beneficial to use when there is perfusion and/or T1 . One such case identified is white and gray matter measurements with hyperpolarized xenon. Thomas Christian Basse-Luesebrink1,2, Thomas Kampf1, Guido Stoll2, Peter Michael Jakob1 1Experimental Physics 5, University of Wuerzburg, Wuerzburg, Germany; 2Neurology, University of Wuerzburg, Wuerzburg, Germany Fluorine markers can possess a unique spectral 19F signal. Therefore, chemical shift imaging (CSI) methods can be used to distinguish between targets labeled with different fluorine markers. Certain PFC compounds, however, have only a small difference in the chemical shift and thus spectrally selective imaging or standard CSI methods are difficult to apply. This study focuses on two alternative methods to separate PFC compounds with a small chemical shift difference: a TSE sequence based on Dixon's method, often used to separate fat from water signal, and a recently presented ssfp Chimera method providing a specific off-resonant behavior. 994. Quantitative and Qualitative Renal Sodium-Imaging at 3T Stefan Haneder1, Simon Konstandin2, Frank G. Zöllner2, Armin M. Nagel3, Lothar R. Schad2, Stefan O. Schönberg1, Henrik J. Michaely1 1University Medical Center Mannheim, Institute of Clinical Radiology and Nuclear Medicine, Mannheim, Baden-Württemberg, Germany; 2Heidelberg University, Computer Assisted Clinical Medicine, Mannheim, Baden-Württemberg, Germany; 3German Cancer Research Center, Department of Medical Physics in Radiology, Heidelberg, Baden-Württemberg, Germany Sodium imaging before/after water load (1L) was performed with 9 healthy volunteers. A density adapted 3D radial trajectory gradient-echo sequence was used at a 3T clinical MR scanner. Linear cortico-medullary sodium gradients were assessed before/after water load. Using standardized sodium phantoms these gradients were quantified. A decrease of the quantitative sodium concentration of about 22% after water load was stated. This study suggests that sodium imaging might be an appropriate, noninvasive method for physiological imaging of the human kidney. The current technique is sufficient for the quantification of the renal sodium concentration and its change in different physiological conditions. 995. 2D and 3D Spectrally Selective 31P Imaging at 3 Tesla Haoyang Xing1,2, Hao Shen3, Hehan Tang1, Xiaoqi Huang1, Qiyong Gong1, Xiaohong Joe Zhou2,4 1Center for MR Research, West China Hospital, Sichuan University, Chengdu, Sichuan, China; 2Center for MR Research, University of Illinois Medical Center, Chicago, IL, United States; 3GE Healthcare, Beijing, China; 4Departments of Radiology, Neurosurgery, and Bioengineering, Chicago, IL, United States Characterization of phosphocreatine (or PCr) in biological tissues can provide valuable information on tissue physiology and metabolism and may lead to sensitive disease markers. We have developed 2D and 3D spectrally selective PCr imaging techniques on a human 3T MRI scanner. Low resolution PCr images (32x32) can be obtained in 10.8 minutes with an SNR of ~4, boding well for further developing these techniques for human applications. Muhammed Yildirim1,2, Anke De Vries2, Monique Berben1, Caren van Cammen3, Klaas Nicolay2, Holger Gruell1,2, Rolf Lamerichs1 1Philips Research, Eindhoven, Netherlands; 2Biomedical NMR, Faculty of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 3Maastricht University, Maastricht, Netherlands MR molecular imaging method based on 19F targeted nanoparticles and novel imaging sequences promises potential use in examining angiogeneic processes taking place in the ovaries and the endometrium in situ. Angiogenesis in the urogenital organ of the femal plays a vital role endometriosis, endoendometrial cancer and infertility. Jacob Wheatley Myerson1, Megan M. Kaneda1, Gregory M. Lanza1,2, Samuel A. Wickline1,2 1Biomedical Engineering, Washington University, Saint Louis, MO, United States; 2Department of Medicine, Washington University, Saint Louis, MO, United States Perfluorocarbon nanoparticles were functionalized to deliver VCAM-1 siRNA to human melanoma cells. Delivery was quantified via 19F magnetic resonance spectroscopy. For future in vivo studies, an MR-trackable delivery agent would aid in the determination of localization of siRNA delivery to specific tissues. 998. The Loss of Sodium Homeostasis and Apoptosis During Rodent Glioma Chemotherapy Victor D. Schepkin1, Cathy W. Levenson2, Fabian F. Calixto-Bejarano2, William W. Brey1, Petr L. Gor'kov1 1CIMAR, NHMFL/FSU, Tallahassee, FL, United States; 2College of Medicine, FSU, Tallahassee, FL, United States The goal of the present study was to assess the hypothesis that an in vivo increase of intracellular sodium is one of the first and a crucial stage during cancer therapy. Experiments were performed using high resolution sodium and diffusion MRI at 21.1T and rodent glioma model. During efficient BCNU chemotherapy, tumor sodium reaches a plateau indicating a complete loss of Na homeostasis at day 4 following the initiation of therapy. Dose dependent responses of intracellular sodium can serve as a very early biomarker for the onset of apoptosis and forecast tumor elimination. Muhammed Yildirim1,2, Shelton D. Caruthers3, Aart J. Nederveen4, Jaap Stoker4, Rolf Lamerichs1 1Philips Research, Eindhoven, Netherlands; 2Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 3Washington University, St Louis, MO, United States; 4Department of Radiology, Academic Medical Center, Amsterdam, Netherlands In vivo 3D F-uTSI, can distinguish various 19F compounds based on chemical shift differences allowing for multicolor imaging, without additional increase in scan time. 3D F-uTSI is an efficient spectral imaging technique; data with a resolution of 48x48x14 can be recorded with a scan-time of 6:23m. The spectra of several Perfluorocarbon emulsion can be uniquely identified from these data. Main advantage of the spectroscopic, multicolor, imaging approach is that the spectral images of the different PFC agents are recorded at the same time and, furthermore, complex biological process can be imaged using co-injection of differently functionalized PFC emulsions. 1000. Sodium MR Imaging in the Study of Hepatic Encephalopathy Nadim Jon Shah1,2, Vincent Gras1, Anna-Maria Oros-Peusquens1, Eberhard Daniel Pracht1, Sandro Romanzetti1, Gerald Kircheis3, Dieter Häussinger3 1Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Forschungszentrum Jülich GmbH, Jülich, Germany; 2Faculty of Medicine, Department of Neurology, RWTH Aachen University, Aachen, Germany; 3Klinik f. Gastroenterologie, Hepatologie und Infektiologie, Universitätsklinikum Düsseldorf, Düsseldorf, Germany Sodium MRI provides an new tool for the analysis of mechanisms involved in hepatic encephalopathy (HE), a neuropsychiatric complication of liver failure. Hyperintense regions observed in the basal ganglia in proton images of HE patients are expected to show changes in sodium images due to the involvement of hyponatraemia in HE. Using sodium MRI, expected subtle changes are investigated using the structural information - delineation of structures of interest - provided by anatomical MR images. Based on the analysis of a large group of patients versus controls, this research potentially provides novel, valuable information concerning metabolic changes in HE. 1001. Efficient B0-Inhomogeneity Insensitive TQF 23Na Imaging. Lazar Fleysher1, Niels Oesingmann2, Matilde Inglese3 1Department of Radiology, NYU School of Medicine, New York, United States; 2Siemens Medical Solutions USA, Inc., United States; 3Departments of Radiology and Neurology, NYU School of Medicine, New York, United States We present a new 12-step triple-quantum filtering phase-cycling scheme based on three RF pulses which allows compensation of B0 variations both with and without ancillary B0-map information. The method offers 40% higher SNR efficiency compared to the previously developed phase-cycling schemes.
David Thomas Pilkinton1, Mark A. Elliott1, Jeremy Magland2, Ravinder Reddy1 1Center for Magnetic Resonance and Optical Imaging, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Radiology, University of Pennsylvania, Philadelphia, PA To maximize signal-to-noise ratio (SNR) and minimize relaxation weighting, ultra-short echo (UTE) readouts have been generally been favored for sodium MRI. UTE methods have also been used to measure total sodium concentration (TSC) in tissues, although this typically requires accurate mapping of the B1 field which is typically noisy and error prone. A more reliable quantitative parameter for sodium MRI is the measurement of the long component of the transverse relaxation time, T2L*. In this study, we have implemented a robust sodium imaging sequence for simultaneous UTE imaging and T2L* measurements. 1003. Ex Vivo Assessment of Cervical Remodeling Via 23Na MRS Xiang Xu1, Yucel Akgul2, Mala Mahendroo2, Alexej Jerschow1 1Department of Chemistry, New York University, New York, NY, United States; 2Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX, United States Preterm birth occurs in 12.5% of births in the United States. Greater understanding by which the two main processes, uterine contraction and cervical remodeling are regulated is required to reduce rates of preterm birth. Understanding the changes in glycosaminoglycan (GAG) concentration during cervical remodeling will help elucidate the normal physiological process in the cervix. 23Na NMR spectroscopy is used to evaluate the changes in Na+ concentration in the mouse cervix during pregnancy, labor and postpartum as a means of evaluating the GAG changes during each stage of cervical remodeling. 1004. The 17O Imaging for Regional Oxygen Consumption Rate in Tumor Bearing Mice at 7T Michiko Narazaki1, Yoko Kanazawa2, Hiroo Ikehira2, Tetsuya Matsuda1 1Kyoto University, Kyoto, Japan; 2National Institute of Radiological Sciences, Chiba, Japan The tumor oxygen consumption rate in mice using 17O images was investigated. 17O FISP images were acquired before and after the inhalation of 17O enriched oxygen gas. The increment in the 17O image intensity due to the metabolically generated H217O from 17O2 was converted to the quantity of produced H217O, which was in good agreement with physiological data in literature. We confirmed this method promising as a tool for monitoring the oxygen consumption rate in tumor. 1005. Binomial Sequence for Selective Quadrupolar 23Na in Vitro and in Vivo NMR and MRI Christoffer Laustsen1,2, Steffen Ringaard1, Michael Pedersen1, Niels Christian Nielsen, 2,3 1Klinisk Institut, The MR Research Centre, Aarhus University, Aarhus, Denmark; 2iNano, Aarhus University, Aarhus, Denmark; 3inSPIN, Aarhus University, Aarhus, Denmark The ion potential has a crucial role en cell metabolism, and is therefore a potential diagnostic target for various diseases. The purpose of this study was to investigate the use of the well known water suppression techniques: binomial sequences, for sodium NMR and MRI. We show that the binomial sequences posses many interesting features for different applications for S=3/2 nuclei, mainly that the central peak and the satellite peaks is either excited or suppressed independently, the other feature is the QJR regime, where only the central peak of a given quadrupolar interaction is observed. Elisa Placidi1, Robin C. Spiller2, Penny A. Gowland3 1SPMMRC, School of Physics and Astronomy , University of Nottingham, Nottingham, United Kingdom; 2Nottingham Digestive Diseases Centre Biomedical Research Unit, University of Nottingham, Nottingham, United Kingdom; 3SPMMRC, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom
1007. In Vivo High-Resolution Imaging and T1 Mapping of Brain Sodium at 4T Ana-Maria Oros-Peusquens1, Eberhardt Pracht2, Sandro Romanzetti, N. Jon Shah3 1INM-4, Research Centre Juelich, Juelich, Germany; 2INM-4, Research Centre Juelich, Germany; 3INM-4, Germany High-resolution sodium imaging has been performed in vivo using a 4T whole-body system and a gradient echo sequence. In a monoexponential approximation T1 mapping can be performed in a manner similar to that for protons, using two gradient echo acquisitions. Careful parameter optimisation is required, as well as high SNR. Koji Hirata1, Yosuke Otake1, Shuhei Hashiba1, Yuichiro Hashimoto1, Yoshitaka Bito1, Hisaaki Ochi1 1Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo, Japan A therapeutic drug monitoring system of 5-FU and its metabolites used by 19F MRI is developed. It was demonstrated that 19F MRI can detect tissue distribution of 5-FU and fluoro-beta-alanine (FBAL) in tumor-bearing rats. A liquid chromatography / tandem mass spectrometry (LC/MS/MS) acquired the 5-FU and FBAL concentrations. The relationship between the signal intensity by 19F MRI and concentration by LC/MS/MS in a tumor and liver was evaluated. Clearly, well relationship coefficients were obtained (5-FU: R2>0.82, FBAL: R2>0.96). 1009. Classification of Metabolic Parameters by Anatomically Superimposed Scans (COMPASS) Ian C. Atkinson1, Aiming Lu1, Theodore Claiborne1, Keith R. Thulborn1 1Center for MR Research, University of Illinois- Chicago, Chicago, IL, United States The limited resolution of quantitative sodium MR imaging data complicates interpretation. We present a sceme for using tissue classifications from automatically segmented high-resolution proton data to classify the voxels of tissue sodium concentration maps. 1010. Intra-Cellular Sodium Fraction in the Human Brain at 7T in-Vivo. Lazar Fleysher1, Niels Oesingmann2, Ryan Brown3, Graham Wiggins3, Daniel K. Sodickson4, Matilde Inglese5 1Department of Radiology, NYU School of Medicine, New York, United States; 2Siemens Medical Solutions USA, Inc., United States; 3Department of Radiology and Center for Biomedical Imaging, NYU School of Medicine, New York, United States; 4Departments of Radiology, Physiology and Neuroscience, NYU School of Medicine, New York, United States; 5Departments of Radiology and Neurology, NYU School of Medicine, New York, United States Single quantum and triple-quantum sodium imaging is used to obtain the intracellular sodium fraction from the human brain in-vivo. The fast and slow sodium relaxation rates from the human head at 7T are also reported.
1011. Optimized Resolution of Flexible Twisted Projection Imaging for Sodium MR Imaging Ian C. Atkinson1, Aiming Lu1, Keith R. Thulborn1 1Center for MR Research, University of Illinois- Chicago, Chicago, IL, United States Flexible twisted projection imaging is optimized for true resolution in the setting of sodium MR imaging. This optimization incorporates the effects T2-blurring into the selection of the image acquisition parameters so that the true resolution of the resultant image is optimized. Hyperpolarized Carbon-13 & Other Nuclei Hall B Wednesday 13:30-15:30 1012. Metabolic Imaging of the Perfused Rat Heart Using Hyperpolarized [1-13C]Pyruvate Philip Lee1, Marie Schroeder2, Daniel Ball2, Kieran Clarke2, George Radda1, Damian Tyler2 1Singapore Bioimaging Consortium, Biomedical Sciences Institute, Singapore, Singapore; 2Department of Physiology, Anatomy & Genetics, University of Oxford, United Kingdom Imaging of cardiac metabolism using 13C-MRS is currently hindered by both a low sensitivity and a low natural abundance of 13C. The recent development of liquid state Dynamic Nuclear Polarization (DNP) techniques has dramatically increased the signal available from 13C-MRS experiments and has opened up new possibilities for metabolic imaging of the heart. By injecting hyperpolarized 13C-labeled pyruvate into a perfused rat heart, followed by high spatial resolution chemical shift imaging (CSI) during an optimum acquisition window, we were able to image the bio-distribution of lactate, bicarbonate and alanine within 46 s. 1013. Investigation of Hepatic Metabolism of DNP Hyperpolarized 1,4-13C2 Succinate Jeremy W. Gordon1, Kang Wang1, Sean B. Fain1,2, Ian J. Rowland2 1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Radiology, University of Wisconsin-Madison, Madison, WI, United States This work describes the successful hyperpolarization of 1,4-13C2 succinate using dynamic nuclear polarization (DNP). By optimizing the solubility of succinic acid in aqueous solution, levels of solid state similar to that of pyruvate can be reproducibly obtained. 3.0M solutions of hyperpolarized succinate were utilized to investigate hepatic metabolism in vivo. 13C spectra and imaging show that the biodistribution of succinate within the liver is homogenous. No metabolites were observed in the time frame of the hyperpolarized experiments. Metabolites were also not observed in ex vivo organ homogenates.
1014. Imaging TCA
Cycle Metabolism by PHIP Hyperpolarization of 1,3C
Succinate In Vivo 1Enhanced Magnetic Resonance Laboratory, Huntington Medical Research Institutes, Pasadena, CA, United States; 2Saint Louis University In vivo metabolic imaging of reactions in the Krebs TCA cycle using hyperpolarization was performed using 13C deuterated fumarate that was hydrogenated to 1-13C succinate and hyperpolarized to ~8% by PHIP. On tail-vein injection of hyperpolarized succinate in tumor-bearing mice, hyperpolarized metabolic products were detected with 20,000 fold increased sensitivity over 3-5 minutes. The metabolic fate of hyperpolarized succinate differed in two tumors: in RENCA renal carcinoma metabolic products malate, fumarate, glutamate and citrate were defined, and in Lymphoma A20 the metabolic products were limited to malate. These differences are tentatively assigned to the presence of hypoxia inducing factor HIF1α. 1015. Exploring Multi-Shot Non-CPMG for Hyperpolarized 13C Metabolic MR Spectroscopic Imaging Yi-Fen Yen1, Patrick Le Roux2, Dirk Mayer3,4, Atsushi Takahashi1, James Tropp1, Dan Spielman3, Adolf Pfefferbaum4,5, Ralph Hurd1 1Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States; 2Global Applied Science Laboratory, GE Healthcare, France; 3Radiology, Stanford University, Stanford, CA, United States; 4Neuroscience Program, SRI International, Menlo Park, CA, United States; 5Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States We explored the feasibility of a multi-shot non-CPMG sequence for hyperpolarized 13C metabolic imaging. The sequence is designed to stabilize the longitudinal magnetization while keeping the transverse magnetization refocused, permitting echo-train readouts following multiple low-flip-angle excitations. Thus, acquisition strategies can be developed to take advantage of the long T1 and T2 relaxation times of hyperpolarized 13C metabolites. We demonstrate two of the potential applications, 2D T2 mapping and 3D MR spectroscopic imaging, on 13C phantoms and animals with hyperpolarized 13C-pyruvate injections. Dirk Mayer1,2, Yi-Fen Yen3, Atsushi Takahashi3, James Tropp3, Brian K. Rutt2, Ralph E. Hurd3, Daniel M. Spielman2, Adolf Pfefferbaum1,4 1Neuroscience Program, SRI International, Menlo Park, CA, United States; 2Radiology, Stanford University, Stanford, CA, United States; 3GE Healthcare, Menlo Park, CA; 4Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States Using undersampled 13C spiral chemical shift imaging (CSI) in combination with a high-performance gradient insert we achieved single-shot hyperpolarized 13C metabolic imaging of the rat in a clinical 3T MR scanner. With an acquisition time of 125 ms, the method produced metabolic images of pyruvate and its metabolic products lactate and alanine with similar quality as with conventional CSI using phase encoding, despite an almost 200-fold reduction in acquisition time. Because the longitudinal magnetization does not recover in hyperpolarized MRI, there is no intrinsic SNR disadvantage of the faster imaging method. Sonal Josan1,2, Yi-Fen Yen3, Ralph Hurd3, Adolf Pfefferbaum4, Daniel Spielman2, Dirk Mayer, 12 1SRI International, Menlo Park, CA, United States; 2Radiology, Stanford University, Stanford, CA, United States; 3Applied Sciences Laboratory, GE Healthcare, Menlo Park, CA, United States; 4Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States Undersampled spiral CSI (spCSI) with free induction decay (FID) acquisition allows real-time metabolic imaging of hyperpolarized 13C. Phase correction of the FID acquisition can be difficult, especially with contributions from aliased out-of-phase peaks. This work extends the spCSI sequence to incorporate a double spin-echo obtaining high quality spectra in magnitude mode. It also provides an added benefit of attenuating signal from flowing spins. Lasitha Senadheera1, Dirk Mayer2,3, Moses Darpolor2, Yi-Fen Yen4, Lei Xing1, Daniel Spielman2 1Radiation Oncology, Stanford University, Stanford, CA, United States; 2Radiology, Stanford University, Stanford, CA, United States; 3Neuroscience Program, SRI International, Menlo Park, CA, United States; 4Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States Radiation dose to the tumors is often limited by the irradiation of adjacent organs at risk, such as kidneys. Unlike structural change, metabolic response may reflect early signs of radiation damage in tissues, offering opportunity to better design radiotherapy. Following hyperpolarized [1-13C]pyruvate injection, 13C MRSI was employed to detect radiation-induced metabolic response in rat kidneys at various radiation doses and postirradiation times. No trend in Lactate/pyruvate ratios was observed between irradiated and normal kidneys of the same animal. Metabolic response of irradiated kidneys might not be strong enough to become visible in 13C MRSI, within our experimental errors and conditions. Dirk Mayer1,2, Yi-Fen Yen3, Atsushi Takahashi3, Sonal Josan1,2, James Tropp3, Adolf Pfefferbaum1,4, Ralph E. Hurd3, Daniel M. Spielman2 1Neuroscience Program, SRI International, Menlo Park, CA, United States; 2Radiology, Stanford University, Stanford, CA, United States; 3GE Healthcare, Menlo Park, CA; 4Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States Time-resolved spiral chemical shift imaging was applied to investigate the uptake dynamics in the anesthetized rat brain after injection of hyperpolarized [1-13C]-pyruvate. Additionally, metabolic imaging at high spatial resolution was performed to better characterize the spatial origin of the metabolite signals. Higher lactate (Lac) and bicarbonate (Bic) signals were found in cortical regions of the brain. This could be due to higher flux of Pyr through the blood-brain barrier, faster substrate-to-product conversion, or both. Metabolite time courses from a region-of-interest in the cortex suggest slower production of Bic compared to Lac. 1020. Simultaneous Proton and Hyperpolarized Carbon Imaging Eric Peterson1, Kang Wang2, Krishna Kurpad3, Matthew Erickson2, Ian Rowland3, Sean Fain2,3 1Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States; 2Medical Physics, University of Wisconsin - Madison, Madison, WI, United States; 3Radiology, University of Wisconsin - Madison, Madison, WI, United States Current hyperpolarized carbon protocols call for all of the scans to be performed in series, including the proton localizer and carbon metabolic image. The localizer image is typically acquired at a higher resolution than the carbon image, and eventually serves as an anatomical reference for the later carbon acquisition. By performing a simultaneous proton and carbon acquisition, several potential applications are possible such as continuous localization, motion tracking and compensation, or targeted excitation. Isabelle Iltis1, Dinesh Kumar Deelchand1, Malgorzata Marjanska1, Gregor Adriany1, Manda Vollmers1, Kamil Ugurbil1, Pierre-Gilles Henry1 1Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States Recently, we have shown detection of [1-13C]lactate in the normal brain in vivo after injection of hyperpolarized [1-13C]pyruvate. However, the spatial origin of the detected [1-13C]lactate signal has been a matter of debate. In the present work, a coil specifically designed to detect 13C resonances in the carotid of anesthetized, living rats was used to detect signals from the blood. We show that no lactate signal is detected in the carotid after injection of hyperpolarized [1-13C]pyruvate, hereby demonstrating that the lactate signal observed in the brain originates from tissue metabolism. Shingo Matsumoto1, Doug Morris2, Martin Lizak2, Jeeva P. Munasinghe2, Keita Saito1, Jan Henrik Ardenkjaer-Larsen3, Sankaran Subramanian1, Nallathamby Devasahayam1, Kevin Camphausen1, Alan Koretsky2, James B. Mitchell1, Murali C. Krishna1 1National Cancer Institute, Bethesda, MD, United States; 2National Institute of Neurological Disorder and Stroke, Bethesda, MD, United States; 3GE Healthcare, Amersham, United Kingdom Many tumor types can undergo aerobic glycolysis, where tumors can abnormally obtain as much as 50% of their energy (ATP) by metabolizing sugar glucose directly to lactate even in the presence of oxygen. Likewise, approximately one half of tumors exhibit marked hypoxia. Collectively, these traits can contribute to resistance to cancer treatments. Non-invasive assessment of altered tumor metabolism and tissue hypoxia might be useful for both diagnostic and treatment strategies. In this study EPR oxygen imaging and hyperpolarized MRI of 13C-labeled pyruvic acid, are coupled to provide a measure of tumor hypoxia and energy metabolism. 1023. Metabolism of Hyperpolarized 1-13C-Lactate in Living Breast Cancer Cell Cultures Talia Harris1, Galit Eliyahu2, Lucio Frydman1, Hadassa Degani2 1Chemical Physics, Weizmann Institute of Science, Rehovot, Israel; 2Biological Regulation, Weizmann Institute of Science, Rehovot, Israel The enhanced polarization enabled by ex situ Dynamic Nuclear Polarization may allow us to follow metabolic processes non-invasively with unprecedented sensitivity and temporal resolution. In order to understand the altered metabolism of cancer and screen for additional biomarkers we have developed a perfusion-infusion bioreactor, allowing hyperpolarized metabolic measurements on living cell cultures. In this work we compare the metabolism of 1-13C-Pyruvate and 1-13C-Lactate in breast cancer cells. The kinetic measurements allow us to demonstrate that the metabolism of 1-13C-Lactate is transport limited, as was previously established for 1-13C-Pyruvate. 1024. Modeling of Pyruvate/Lactate Kinetics Using a Two-Site Exchange Model Aaron Keith Grant1, Elena Vinogradov1, Pankaj K. Seth1, Xiaoen Wang1, Robert E. Lenkinski1, Vikas P. Sukhatme1 1Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States Hyperpolarized pyruvate undergoes rapid conversion into lactate, alanine, and bicarbonate in vivo. Lactate is of particular interest as elevated lactate levels may serve as a biomarker for cancer. Although lactate SNR has been shown to correlate with histological characteristics of tumors, quantitative measures of kinetics are desirable. We present fits of a simple two-site exchange model to data acquired in an animal model of non-small lung cancer, and show that these methods can quantify reductions in lactate formation rates following administration of dichloroacetate, a drug that up-regulates the activity of pyruvate dehydrogenase. Francesca Frijia1, Luca Menichetti1, Vincenzo Positano1, Vincenzo Lionetti2, Claudia Forte3, Jan H. Ardenkjaer-Larsen4, Matteo Milanesi1, Giulio Giovannetti1, Daniele De Marchi1, Giovanni Aquaro1, Manuela Campan2, Fabio A. Recchia5, Luigi Landini1, Maria Filomena Santarelli1, Massimo Lombardi1 1MRI Lab, "G. Monasterio" Foundation and Institute of Clinical Physiology, Pisa, Italy; 2Sector of Medicine, Scuola Superiore Sant'Anna, Pisa, Italy; 3Istituto per i Processi Chimico Fisici, CNR,, Pisa, Italy; 4GE Healthcare, Huginsvej 8, 3400 Hillerod,, Denmark; 5Department of Physiology, New York College, Valhalla, New York Changes in metabolic products of pyruvate can be correlated to the patho-physiological condition of the myocardium: The cardiac oxidation of pyruvate depends on oxygen delivery to myocardium and on the activation state of mitochondrial pyruvate dehydrogenase. The real time tracking of the metabolic fate of pyruvate in the intact heart with MRS would provide a key information on the state of myocardium in response to a variety of stimuli. This study deal with the real time in vivo cardiac metabolism after intravenous injection of hyperpolarized [1-13C]-pyruvate in the animal of mid size with a 3T scanner with regards to the typical kinetic profile of accumulation of each metabolite and if the typical pattern could be modelled with simple equations. James Tropp1 1Global Applied Science Lab, GE Healthcare Technologies, Fremont, CA, United States We present density matrix calculations of the carbon spectra of doubly labelled hyperpolarized [1, 2 -13C2] pyruvate at 3.0 tesla, showing the combined effects of hyperpolarization and strong scalar coupling upon the asymmetry of the multiplet lineshapes. The possibility is discussed of using the asymmetry to measure hyperpolarization in situ. The importance of multi-spin order in causing the asymmetry is discussed. 1027. A Simple and Accurate Method for 13C Coil Sensitivity Estimation Giulio Giovannetti1, Francesca Frijia2, Luca Menichetti1, Maria Filomena Santarelli1, Valentina Hartwig1, Luigi Landini3, Massimo Lombardi2 1Institute of Clinical Physiology, National Research Council, Pisa, Italy, Italy; 2"G. Monasterio" Foundation, Pisa, Italy; 3Department of Information Engineering, University of Pisa Hyperpolarization methods have been proposed to enhance the polarization of nuclear spins such as 13C. Efficient imaging of such molecules requires new multifrequency coils. However, when the coil are tuned at lower frequency with respect to 1H frequency, such as for 13C experiments, the SNR decreases. Since the SNR performance increases as the sensitivity of the coils it is important to estimate this parameter for an optimized coil design. The purpose of this work is to verify the accuracy of perturbing spheres method for coil sensitivity estimation, by testing two 13C birdcages and demonstrating its efficacy for coil sensitivity estimation. 1028. Effect of Binding on Hyperpolarized MR Signals Kayvan R. Keshari1, David M. Wilson, Daniel B. Vigneron, Jeffrey M. Macdonald2, John Kurhanewicz 1University of California, San Francisco, San Francisco, Ca, United States; 2University of North Carolina, Chapel Hill The purpose of this study was to use hyperpolarized 13C-spectroscopy in the benzoic acid-β-cyclodextrin system to understand the relationship between binding and loss of hyperpolarized signal. The apparent T1 relaxation times for the C1 and C2 carbons of benzioc acid decreased in the presence of β-cyclodextrin, and the changes in T1 relaxation with benzoic acid concentration were used to determine the binding constant (log K 1.68-1.74). Hyperpolarized 13C-spectroscopy may have a role in the rapid screening of small molecular weight drug binding constants in vitro and determining the impact of enzymatic binding on hyperpolarized metabolic probe T1s. 1029. Hyperpolarised Combretastatins: Potential Bio-Marker for Vascular Targeting of Tumours. Steven Reynolds1, Joanne Bluff1, Gillian M. Tozer1, Martyn Paley1 1School of Medicine, University of Sheffield, Sheffield, United Kingdom Combretastatin vascular targeting drug CA-4-P is a complementary approach to cancer therapy. For clinical evaluation of new agents we are developing bio-imaging markers to determine pharmakinetic and pharmadynamic response to rat tumour models. Using Dynamic Nuclear Polarisation (DNP) we have shown that CA-4-P can be 13C hyperpolarised and observed by in vitro 13C NMR spectroscopy. By measuring 13C T1 relaxation times we discuss 13C labelling strategies to permit observation of this molecule and its daughter products in an in vivo tumour rat model. 1030. In Vivo Hyperpolarized 89Y Studies in a 9.4T Animal Scanner Matthew E. Merritt1,2, M Mishovsky3,4, T. Cheng3, Ashish Jindal5, Zoltan Kovacs5, Craig Malloy5,6, Rolf Gruetter3,7, A Dean Sherry5,8, Arnaud Comment3,9 1Advance Imaging Research Center, UT Southwestern Med. Center, Dallas, TX, United States; 2Radiology, UTSW Medical Center, Dallas, TX, United States; 3Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Federal de Lausanne, Lausanne, Switzerland; 4Radiology, Universite de Lausanne, Lausanne, Switzerland; 5AIRC, UTSW Medical Center, Dallas, TX, United States; 6Cardiology, North Texas VA Hospital, Dallas, TX, United States; 7Radiology, Universite de Geneve, Geneva, Switzerland; 8Chemistry, University of Texas at Dallas, Richardson, TX, United States; 9Institute of Condensed Matter Physics , Ecole Polytechnique Federal de Lausanne, Lausanne, Switzerland In vivo 89Y MRS of a rat kidney was performed in a 9.4 T animal scanner after infusion of hyperpolarized 89Y(DOTA) -. The hyperpolarized solution was prepared by dynamically polarizing the 89Y nuclear spins of the Y3+ complexes at 5 T and 1.05 K using the TEMPO free radical. The rapid injection of the solution led to subsequent large in vivo 89Y signal detected in the rat kidney. It was observed that the decay time of the signal is long enough to perform hyperpolarized 89Y in vivo studies. 1031. Measurement of Laser Heating in Spin Exchange Optical Pumping by NMR Diffusion Sensitisation Steven Richard Parnell1, Martin H. Deppe1, Salma Ajraoui1, Juan Parra-Robles1, Stephen Boag2, Jim M. Wild1 1Unit of Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom; 2ISIS Facility, STFC We detail in-situ measurement of the temperature/pressure of alkali metal spin-exchange optical pumping (SEOP) cells containing 3He. A means of measuring cell temperature and laser heating with NMR is demonstrated using a simple 1-D gradient imaging system. Bob C. Hamans1, Sybren S. Wijmenga2, Arend Heerschap1, Marco Tessari2 1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 2Biophysical Chemistry, Radboud University Nijmegen, Nijmegen, Netherlands Hyperpolarization methods can increase nuclear polarization to the order of unity, which corresponds to a sensitivity enhancement of several orders of magnitude with respect to standard NMR techniques based on thermal polarization. In contrast to other hyperpolarization methods like e.g. DNP, PHIP can provide within seconds high degrees of hyperpolarization at moderate experimental conditions and at a relatively low cost per sample. Here we present the application of PHIP to the acquisition of single shot multi nuclear NMR spectrum in the earth magnetic field. 1033. 13C Hyperpolarized Anticoagulants Joachim Bargon1, Johannes Bernarding2, Rahim Rizi3, Hans-Wolfgang Spiess4, Kerstin Münnemann4, Meike Roth4, Ute Bommerich5 1Institute of Physical and Theoretical Chemistry, University of Bonn, Bonn, NRW, Germany; 2Institute of Biometry, University of Magdeburg, Magdeburg, Germany; 3Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 4NMR, Max-Planck Institute of Polymers, Mainz, Germany; 5Institute of Neurobiology, Magdeburg, Germany Anticoagulants like warfarin, phenprocoumon, and pentoxifylline are used to alleviate the disabling consequences of strokes, the leading cause of disability in the US and third leading cause of death. Similarly, the phosphodiesterase inhibitor pentoxifylline inhibits multiple processes including inflammation, coagulation, and edema that lead to neonatal hyperoxic lung injury, whereby. bronchopulmonary dysplasia is a leading cause of mortality and morbidity in preterm infants despite improved treatment. All of these anticoagulants can be 13C-hyperpolarized for 13C-MRI/MRS-studies upon parahydrogenation of suitably unsaturated precursors, preferably at low magnetic fields. Differing from DNP, this procedure can provide a steady flow of 13C-hyperpolarized drugs. Electron Spin Resonance Hall B Thursday 13:30-15:30 Hironobu Yasui1,2, Shingo Matsumoto1, Jeeva P. Munasinghe3, Nallathamby Devasahayam1, Sankaran Subramanian1, James B. Mitchell1, Murali C. Krishna1 1National Cancer Institute, Bethesda, MD, United States; 2Hokkaido University, Hokkaido, Japan; 3National Institute of Neurological Disorder and Stroke Structural and functional abnormality of blood vessels within malignant tumors influences delivery of oxygen, a key radio-sensitizer, resulting in two different types of hypoxia. Chronic hypoxia is attributed to large diffusion distances between tumor microvessels and longitudinal oxygen gradient, whereas acute hypoxia is though to be the result of transient vascular occlusion and fluctuation in red blood cell flux. Electron paramagnetic resonance (EPR) imaging is a sensitive method to non-invasively map tissue oxygenation distribution. To investigate the fluctuation of tumor oxygen concentration, dynamic 3D EPR oxygen imaging was applied to two different types of tumor bearing in mouse. 1035. Assessment of Rapamycin Effects on Tumor Oxygenation and Angiogenesis by Using EPRI and MRI Keita Saito1, Shingo Matsumoto1, Nallathamby Devasahayam1, Sankaran Subramanian1, Jeeva P. Munasinghe2, Vyomesh Patel3, Silvio Gutkind3, James B. Mitchell1, Murali C. Krishna1 1National Cancer Institute, Bethesda, MD, United States; 2National Institute of Neurological Disorder and Stroke; 3National Institute of Dental and Craniofacial Research Effects of anti-tumor drug rapamycin on tumor oxygenation and angiogenesis in tumor bearing mice were investigated by using pulsed electron spin resonance imaging and magnetic resonance imaging. Blood volume in tumor region was significantly decreased after 2 days from beginning of the rapamycin treatment. Tumor oxygenation did not drastically change by rapamycin treatments, but pO2 level slightly increased and the ratio of hypoxic area to tumor region slightly decreased after 2 days rapamycin treatments. These results suggest that rapamycin can normalize blood volume and suppress depletion of oxygen in the tumor region. Philippe Levźque1, Julian Leprince2,3, Ana Maria Dos Santos-Goncalvez2, Gaėtane Leloup2, Bernard Gallez1 1Biomedical magnetic resonance unit, Université catholique de Louvain, Brussels, Belgium; 2School of Dentistry and Stomatology, Université catholique de Louvain, Brussels, Belgium; 3Laboratory of Polymer Science, Université catholique de Louvain, Louvain-la-Neuve, Belgium Methacrylate resins are highly popular in dentistry and are largely used in clinic for tooth restoration. Free radicals are created during the photopolymerization process and can be detected by EPR spectroscopy. EPR has been successfully used to study the mechanical properties of this material. This study focuses on the feasibility of EPRImaging using dental resins which exhibits complex signal. 2D imaging and 2D spectral spatial imaging were applied and give the unique possibility of non destructive characterization and mapping of free radicals in dentam resins and more generally in biomaterials and materials science. Microscopy Hall B Monday 14:00-16:00 Nina Kristine Reitan1, Marte Thuen2, Pål Erik Goa3 1Department of Physics, NTNU, Trondheim, Norway; 2Department of Circulation and Medical Imaging, NTNU, Trondheim, Norway; 3Department of Radiology, St. Olavs Hospital, Trondheim, Norway By using confocal laser scanning microscopy (CLSM) and MRI we studied microvascular architecture and permeability in tumors growing in dorsal window chambers in mice. 40 kDa dextran and Gadomer was used as molecular tracers for dynamic CLSM and DCE-MRI, respectively. Correlation was found between permeability measured by the two techniques and permeability further depended on structural parameters, like fractal dimension and vascular density. This study demonstrates that the dorsal window tumor model gives an opportunity to use CLSM and MRI as supplementary techniques and that CLSM provides insight into the spatial heterogeneous microenvironment on a microscopic level that is not accessible with MRI. Valeria Righi1,2, Alex A. Soukas3, Gary Ruvkun3, A Aria Tzika1,2 1NMR Surgical Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States; 2Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, United States; 3Department of Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States We demonstrate metabolic biomarker profiles with high-resolution magic angle spinning proton MR spectroscopy (HRMAS H1 MRS) of living Caenorhabditis elegans (C. elegans) worms. This work opens up perspectives for the use of H1 HRMAS-MRS as a metabolic profiling method for C. elegans. Because it is amenable to high throughput and is shown to be highly informative, this approach may lead to a functional and integrated metabolomic analytic approach of the small organism C. elegans, which has been used extensively in studies of aberrant metabolism, and should help in identifying, investigating, and even validating new pharmaceutical targets for metabolic diseases.
Ilya Michael Nasrallah1, Sungheon Kim2, Ranjit Ittyerah1, Stephen Pickup1, John H. Wolfe3,4, Harish Poptani1 1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2New York University; 3Departments of Pathobiology and Pediatrics, University of Pennsylvania; 4Children's Hospital of Philadelphia Mucopolysaccharidosis Type VII (MPS VII) is one of the degenerative lysosomal storage diseases characterized by intracellular vacuolization. Using high-resolution MRI in a mouse model of MPS VII with manual segmentation, we identify decreases in corpus callosum and anterior commisure volume and slight increase in hippocampus volume in mutant mice. A decrease in corpus callosum volume thickness is confirmed at histology. These parameters could be used for monitoring experimental response to gene therapy treatments. 1040. MRI Phenotyping of Craniofacial Development in Transgenic Mice Embryos Hargun Sohi1, Seth Ruffins1, Yang Chai2, Scott Fraser1, Russell Jacobs3 1Caltech; 2USC; 3Caltech, Pasadena, CA, United States Microscopic MRI (μMRI) is an emerging technique for high-throughput phenotyping of transgenic mouse embryos, and is capable of visualizing abnormalities in craniofacial development. μMRI methods rely on reduction of the tissue T1 relaxation time by penetration of a gadolinium chelate contrast agent. The use of contrast agents is aimed at reducing the T1 relaxation time of the sample thus permitting a decrease in acquisition scan time, and/or increase in image signal-to-noise ratio (SNR), and/or increase in spatial resolution. In this work we apply these technologies to delineating changes in a murine cleft palate model system. Michael David Wong1, X Josette Chen1, R Mark Henkelman1 1Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada The role of MRI in developmental biology, specifically in mouse embryo organogenesis and phenotyping, is significantly increasing due to technologies that allow for high image resolution and throughput. The majority of ex-vivo MRI mouse embryo studies improve image contrast and SNR by immersing the sample into some concentration of Gd-based contrast agent. It is widely believed that all gadolinium-based contrast agents have identical tissue interactions and provide similar MRI images despite the differences in Gd-chelates. Here, relaxivity (r1) variation amongst mouse embryo organs is observed for one class of contrast agents, while homogeneity is seen throughout the embryo for another. Parastou Foroutan1,2, Susanne L. T. Cappendijk3, Samuel C. Grant1,2 1Chemical & Biomedical Engineering, The Florida State University, Tallahassee, FL, United States; 2CIMAR, The National High Magnetic Field Laboratory, Tallahassee, FL, United States; 3Biomedical Sciences, College of Medicine, The Florida State University, Tallahassee, FL, United States Temperature is evaluated as an easy method of increasing contrast in preserved tissue. In this study, excised, fixed brains from the adult male zebra finch were scanned at multiple temperatures between 5-25 Celsius. Relaxation (T1, T2 and T2*), signal-to-noise, relative contrast and contrast-to-noise were measured at each temperature. In addition, high-resolution 3D gradient recalled echo scans were acquired at 40-micron isotropic resolution at each temperature. Although all relaxation mechanisms displayed decreases with temperature, only T2* contrast displayed structural enhancement. The ramifications of these findings are discussed with respect to microimaging studies of preserved tissue samples. 1043. Phenotyping a Novel Mouse Model of Congenital Heart Disease Using μMRI Jon Orlando Cleary1,2, Francesca C. Norris3,4, Karen McCue5, Anthony N. Price3, Sarah Beddow5, Roger J. Ordidge2,6, Peter J. Scambler5, Mark F. Lythgoe3 1Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health , University College London, London, United Kingdom; 2Department of Medical Physics and Bioengineering, University College London, London, United Kingdom; 3Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, London, United Kingdom; 4Centre for Mathematics and Physics in the Life Sciences and EXperimental Biology (CoMPLEX), University College London, London, United Kingdom; 5Molecular Medicine Unit, UCL Institute of Child Health, University College London, London, United Kingdom; 6Wellcome Trust Advanced MRI Laboratory, University College London, London, United Kingdom CHARGE and DiGeorge syndromes are conditions associated with haploinsufficiency of specific genes (CHD7 and TBX1) and are characterised by cardiovascular defects. Knockout mice are an important tool in genetic studies, allowing genes implicated in congenital defects to be identified and characterised. Micro-MRI is an emerging technique for high-resolution cardiac phenotyping, enabling the acquisition of 3D images of multiple embryo in a single scan. Given the phenotypic overlap of these conditions, we examined heart morphology in novel double-knockout mouse embryos (Chd7+/-Tbx1+/-), performing an assessment using MRI. In particular, we identified an increased incidence of ventricular septal defects in these mice. 1044. Optimised µMRI for Phenotyping the Tc1 Model of Down Syndrome Jon Orlando Cleary*1,2, Francesca C. Norris*3,4, Frances K. Wiseman5, Anthony N. Price3, ManKin Choy3, Victor L.J. Tybulewicz6, Roger J. Ordidge2,7, Elizabeth M.C. Fisher5, Mark F. Lythgoe3 1Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health , University College London, London, United Kingdom; 2Department of Medical Physics and Bioengineering, University College London, London, United Kingdom; 3Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, London, United Kingdom; 4Centre for Mathematics and Physics in the Life Sciences and EXperimental Biology (CoMPLEX), University College London, London, United Kingdom; 5Department of Neurodegenerative Disease, UCL Institute of Neurology, University College London, London, United Kingdom; 6MRC National Insitiute for Health Research, London, United Kingdom; 7Wellcome Trust Advanced MRI Laboratory, University College London, London, *equal contribution Staining brain tissue with MR contrast agents is a key part of MR microscopy, enabling enhanced delineation of structures. Although excised brains allow agent to quickly penetrate into tissue, brains left in-skull are less susceptible to damage during tissue extraction and imaging, resulting in more accurate morphometric analyses. We sought to develop an optimised preparation and scanning protocol for imaging adult mouse brains in-skull, determining the timecourse for agent to penetrate into intact brain. Using this protocol we assessed phenotype in Tc1 mice a model of Down Syndrome. We identified ventricular enlargement in 10 of 14 transgenic Tc1+ mice imaged. 1045. MR Microscopy of Zebrafish Miriam Scadeng1, Ellen Breen2, Nathan Gray1, David Dubowitz1 1Radiology, UC San Diego, San Diego, CA, United States; 2Medicine, UC San Diego, San Diego, CA, United States Being a relatively new animal model there is no comprehensive 3D anatomical atlas onto which temporal or spatial data can be projected. In addition, methods for in-vivo imaging of adult fish are needed if zebrafish researchers are to benefit from functional MR imaging techniques such as MRS, MEMRI, BOLD and even ASL that are routinely being used in mouse models of disease. The major challenges include the very small size of the fish, and imaging the live fish in water. We present methods for in-vivo MRI of zebrafish, and a 3D atlas of zebrafish anatomy. 1046. Visualization of Vascular Casts Using 3D MR Imaging Ian Rowland1, Joseph Heintz2, Douglas Steeber3, Ralph Albrecht2 1Department of Radiology, University of Wisconsin, Madison, WI, United States; 2Department of Animal Sciences, University of Wisconsin, Madison, WI, United States; 3Department of Biological Sciences, University of Wisconsin, Milwaukee, WI, United States This study demonstrates that at 4.7T, using a standard 3D gradient echo sequence, images of vascular casts prepared using established corrosion casting techniques may be obtained with an isotropic resolution <50um. Immersion of the casts in aqueous contrast agent enabled 3D representations of the casts to be generated via the absence of MR signal. Despite the lower resolution of MR, surface rendering of the data is able to guide SEM studies to specific regions of interest. Accurate 3D data from vascular casts can be compared with in vivo angiography studies and may also be used to validate direct and indirect methods of measuring vascular dimensions.
1047. EPI Microscopy with Uniplanar Magnetic Field Gradient Coils Lin Zhao1, Andrey V. V. Demyanenko1, J. Michael Tyszka1 1California Institute of Technology, Pasadena, CA, United States A localized small gradient design generates negligible eddy currents and is well-suited for EPI microscopy. Here single shot EPI is demonstrated in both an ex vivo mouse embryo sample and in vivo mouse brain using a prototype three-axis uniplanar gradient design. 1048. MR-Microscopy on a Human 7T-Scanner Andreas Berg1, Andreas Potthast2, Piotr Starewicz3 1MR-Center of Excellence, Center for Biomedical Engineering and Physics, Wien, Vienna, Austria; 2Healthcare Sector, Imaging & IT Division, Magnetic Resonance, Siemens AG, Erlangen, Germany; 3Resonance Research, Inc., Billerica, MA, United States MR-microscopy can be looked upon as key technological tool in MRI-based molecular imaging in biological models and human pathology samples. Is it possible to achieve a pixel-size below 100 µm on high-field human MR-scanners (B≥7T) within 21min at acceptable Signal-to-Noise-Ratio? We present microscopic images at voxel-size of 25x51x200 µm3 and document a spatial resolution higher than 34µm using specifically designed grid-phantoms. The data, according to our knowledge, represents the highest documented spatial resolution obtained yet on such a scanner. The technical equipment based on a high gradient-strength insert coil and sensitive detectors is shortly explained. Suzanne Louise Duce1 1College of Life Sciences, University of Dundee, Dundee, United Kingdom Avian embryos are important models for understanding embryonic development. We undertook a 3D longitudinal μMRI study using 7.1T Bruker of quail eggs imaged daily for 8 days, changes in the extra- and non-embryonic components as well as in the embryo were studied. At Day 0 the yolk, albumen, latebra and chalaza are visible, additional aqueous region is visible from Day 2. The growth of the embryo in-ovo is visualised. The 3D surface reconstructions of the embryo, yolk, albumen, embryonic fluid, and latebra were produced, their respective volumes calculated and changes over time presented graphically. Methodology for MR Elastography Hall B Tuesday 13:30-15:30 1050. Intensity Speckle MR Elastography Sebastian Papazoglou1, Sebastian Hirsch1, Dieter Klatt1, Kaspar Josche Streitberger1, Kerstin Riek1, Thomas Elgeti1, Jürgen Braun2, Ingolf Sack1 1Institute of Radiology, Charité - University Medicine Berlin, Berlin, Germany; 2Institute of Medical Informatics, Charité - University Medicine Berlin, Berlin, Germany In this study we present a statistical analysis of shear wave intensity speckles in magnetic resonance elastography (MRE). The employed statistical model provides a single fit parameter that is related to characteristic structure-related length scales. Hence, the intensity speckle distribution offers the possibility to investigate the elastic heterogeneity of the brain without solving the ill-posed inverse problem associated with shear wave propagation. Results of speckle intensity MRE experiments on gel phantoms and the brain of a healthy subject demonstrate the feasibility of the proposed statistical analysis. 1051. Elastography Liver Stiffness Estimates from Two Phase Samples Roger C. Grimm1, Armando Manduca2, Richard L. Ehman 1Mayo Clinic, Rochester, MN, United States; 2Mayo Clinic, United States Recently, Wang has shown that two phase samples are adequate to generate stiffness estimates in phantom and breast experiments. Acquiring only two phase samples is only justified if the vast majority of the applied energy is occurring at a single frequency. This paper finds that there is virtually no energy contained in the higher harmonics during liver exams. Stiffness maps from inversions of two and four phase samples show a highly linear relationship with a slight underestimation obtained from two phase sample data set due to the root 2 lower SNR. 1052. Ergonomic Flexible Drivers for Hepatic MR Elastography Jun Chen1, David Stanley2, Kevin Glaser1, Meng Yin1, Phillip Rossman1, richard Ehman1 1Department of Radiology, Mayo Clinic, Rochester, MN, United States; 2GE Healthcare, Milwaukee, WI, United States Electromechanical drivers and pneumatic drivers are widely used for in vivo human hepatic MRE. Due to the small size and rigid nature of existing mechanical drivers, the human-driver contact is not able to accommodate the soft and contoured nature of the human body, therefore the mechanical coupling is not optimal and has the potential of causing discomfort to patients. The pneumatic driver system has the same limitations due to it current rigid passive driver, especially for female patients. Our goals were 1) to design an ergonomic pneumatic flexible passive driver to improve human-driver mechanical coupling and patient comfort; and 2) to compare the flexible driver with the rigid passive driver on volunteers and patients. 1053. Characterization of Tumor Vascularization in Mice Using MRE Lauriane Juge1, Bich-Thuy Doan2, Johanne Seguin2, Benoit Larrat3, Jean Herscovici2, Daniel Scherman2, Ralph Sinkus3 1RMN, ENSCP, PARIS, France, Metropolitan; 2UPCG/ENSCP; 3ESPCI Assessment of neoangiogenesis are major challenges in cancerology. We develop a new application of Magnetic Resonance Elastography (MRE) for measuring the viscoelastic properties of tissue changing with the vascularization. Five, nine and fourteen days after implantation of CT26 tumors on Balb-C JRJ mice, MR experiments were performed at 7T. MRI supplied anatomic and quantitative T1 T2 maps. MRE (1000 Hz) measured Gd (elasticity) and Gl (viscosity) parameters, revealing a ring with higher hardness located at the periphery which should correspond to the expected neoangiogenesis. Histopathology was performed to assess the microvascular architecture and necrosis state in coherence with MRI and MRE. 1054. A Convertible Pneumatic Actuator for Brain and Phantom Elastography Peter Latta1, Patricia Debergue2, Marco L.H. Gruwel1, Brendon Matwiy1, Uta Sboto-Frankenstein1, Boguslaw Tomanek1 1MRTechnology, NRC-CNRC Institute for Biodiagnostics, Winnipeg, MB, Canada; 2NRC-CNRC Industrial Materials Institute, Boucherville, QC, Canada We preset a convertible pneumatic actuator design to generate vibration for MRE experiments. The experimental results on both phantoms and volunteers showed that the actuator produces suitable shear waves for the calculation of viscoelastic properties of tissues and materials in the frequency range of 25-150Hz. The unique feature of our design is its flexibility and ease of use. 1055. A Hydraulic Driver System for MR Elastography of Small Animals Michael Neumaier1, Elmar Schuck2, Thomas Kaulisch1, Heiko G. Niessen1, Dieter Klatt3, Ingolf Sack3, Juergen Braun4, Detlef Stiller1 1In-Vivo Imaging Unit, Dept. of Drug Discovery Support, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany; 2Precision Mechanics, Dept. of Site Operations, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany; 3Dept. of Radiology, Charité - University Medicine Berlin, Berlin, Germany; 4Dept. of Medical Informatics, Charité - University Medicine Berlin, Berlin, Germany MR elastography (MRE) is a powerful tool for the non-invasive assessment of liver diseases. It requires the reliable delivery of shear waves in the acoustic frequency range between 25 and 1000 Hz. We present a novel concept of motion generation suitable for MRE of small animals based on a piezoelectric wave generator and a hydraulic transmission system. The new system provides excellent wave penetration of rat liver in the desired frequency range and yields reproducible and consistent results. Jessica Mende1, Marcus Radicke1, Anna-Lisa Kofahl1, Judith Schindler1, Deniz Ulucay1, Jürgen Finsterbusch2, Bernd Weber3, Karl Maier1 1HISKP, University of Bonn, Bonn, Germany; 2University Medical Center, University of Hamburg, Hamburg, Germany; 3NeuroCognition, Life & Brain, Bonn, Germany Acoustic radiation contrast in magnetic resonance phase images is a recently developed method to image and quantify non-invasively the viscoelastic properties of tissue. A displacement sensitive MRI spin-echo sequence was used to image the displacement caused by the acoustic radiation force of ultrasound with a frequency of 2.5 MHz, a pulse length of 20 ms and an intensity of 35 W/cm2. To show the feasibility of this method, results of the detection of lesions in a breast elastography phantom are presented. Finite-element simulations show good agreement with the experimental data. 1057. Tissue Stiffness Estimation Using Gaussian Filters for Prostate MR Elastography Frank Zhao1, Arvin Arani1,2, Don Plewes1,2, Rajiv Chopra1,2 1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; 2Medical Biophysics, University of Toronto, Toronto, Ontario, Canada Transurethral MR elastography offers the potential to obtain high resolution stiffness images of the prostate gland. The purpose of this study was to adapt the local frequency estimator algorithm for the radial shear wave geometry associated with this approach. The stiffness estimates were compared between the conventional and modified LFE method. 1058. Acoustic Radiation Contrast in Magnetic Resonance: Detection of Microcalcifications Judith Schindler1, Deniz Ulucay1, Jessica Mende1, Marcus Radicke1, Anna-Lisa Kofahl1, Jürgen Finsterbusch2, Robert Krieg3, Karl Maier1 1HISKP, University of Bonn, Bonn, Germany; 2University Medical Center, University of Hamburg, Hamburg, Germany; 3Siemens Healthcare, Erlangen, Germany One promising application of acoustic radiation contrast in magnetic resonance (ARC-MR) phase images is the detection of microcalcifications (tiny abnormal deposits of calcium) in breast tissue. Acoustic radiation force was applied using a custom-made MR-compatible piezoelectric transducer with a resonance frequency of 2,5 MHz. The thus produced displacement in the phantom was made visible with a displacement sensitive spin-echo sequence. The phantom was an agar/de-ionized water solution containing glass beads to get tissue-like ultrasound absorption. Results show that an eggshell (1mmx1mm) that mimics the microcalcification is only visible in MR phase images when the ultrasound is turned on. Drug Discovery Hall B Wednesday 13:30-15:30 Alexandre Coimbra1,2, Richard Baumgartner, 2,3, Dai Feng, 2,3, Shubing Wang3, Jaymin Upadhyay, 2,4, Adam Schwarz, 2,5, Julie Anderson, 2,4, Lauren Nutile, 2,4, Gautam Pendse, 2,4, James Bishop, 2,4, Ed George, 2,4, Smiriti Iyengar, 2,5, David Bleakman, 2,5, Richard Hargreaves, 2,6, Jeff Evelhoch1,2, David Borsook, 2,4, Lino Becerra, 2,4 1Imaging, Merck Research Laboratories, West Point, PA, United States; 2Imaging Consortium for Drug Development, Belmont, MA, United States; 3Biometrics, Merck Research Laboratories, Rahway, NJ, United States; 4PAIN, McLean Group, Belmont, MA, United States; 5Lilly Research Laboratories, Indianapolis, IN, United States; 6Neurosciences, Merck Research Laboratories, West Point, PA, United States It has been suggested that fMRI functional connectivity metrics may be useful tools to test efficacy of CNS therapeuticals. This work provides initial exploration of functional connectivity approaches based on Independent Component Analysis. This is done in the context of a Placebo Controlled study of Buprenorphine, a partial opioid agonist and antagonist. A set of previously reported fundamental resting state networks (RSNs) were examined comprising of medial visual, lateral visual, auditory system, sensory motor system, default mode network, executive control, dorsal visual stream. Treatment effects of Buprenorphine on functional connectivity metrics associated with each of these fundamental RSNs were examined. Fuqiang Zhao1, Denise Welsh1, Mangay Williams1, Alexandre Coimbra1, Mark O. Urban2, Richard Hargreaves2, Jeffrey Evelhoch1, Donald S. Williams1 1Imaging Department, Merck Research Laboratories, West Point, PA, United States; 2Neuroscience Department, Merck Research Laboratories, West Point, PA, United States To validate the fMRI signals in the spinal cord and the brain of rats induced by noxious stimulation as a pain biomarker, and to determine its utility in elucidation of mechanisms of action of analgesics, the effect of buprenorphine (BPN), a partial ģ-opioid agonist, on pain fMRI signals was investigated. The pain fMRI signals in the caudate putamen and thalamus region were totally suppressed, while those in spinal cord, cerebellum, thalamic relay of somatosensory pathway, and primary somatosensory cortex were only partially (if at all) suppressed. Such a suppression pattern is consistent with the density of ģ opioid receptor distribution in brain, supporting the idea that fMRI can provide anatomical action sites of the analgesics, which should help to understand their mechanisms of action. Roelof Peter Soeter1,2, Linda E. Klumpers3, Naj Khalili-Mahani1,2, Mark A. van Buchem1,2, Serge A.R.B. Rombouts1,2, Joop M.A. van Gerven, 3,4 1Department of Radiology, Leiden University Medical Center (LUMC), Leiden, Netherlands; 2Leiden Institute for Brain and Cognition (LIBC), Leiden, Netherlands; 3Centre for Human Drug Research, Leiden, Netherlands; 4Department of Neurology, Leiden University Medical Center (LUMC), Leiden, Netherlands Resting state FMRI is a promising technique for drug studies, because it allows a repeated task-independent assessment of functional interactions between brain regions (functional connectivity). Here we investigate the effects of THC, the psychoactive compound of cannabis, on functional brain connectivity. Nine healthy male volunteers participated in a randomised, double blind, placebo-controlled trial in which 8 RS-FMRI scans were obtained in each treatment occasion. THC administration decreased connectivity in different brain regions, including cerebellum and several cortical regions. Functional connectivity using RS-FMRI is a promising new technique to study pharmacologically induced changes in brain activity.
Alexandre Coimbra1,2, Richard Baumgartner, 2,3, Sonya Apreleva, 2,3, Jaymin Upadhyay, 2,4, Adam Schwarz, 2,5, Julie Anderson, 2,4, Lauren Nutile, 2,4, Gautam Pendse, 2,4, James Bishop, 2,4, Ed George, ,2,4, Smiriti Iyengar, 2,5, David Bleakman, 2,5, Richard Hargreaves, 2,6, Jeff Evelhoch1,2, Lino Becerra, 2,4, David Borsook, 2,4 1Imaging, Merck Research Laboratories, West Point, PA, United States; 2Imaging Consortium for Drug Development, Belmont, MA, United States; 3Biometrics, Merck Research Laboratories, Rahway, NJ, United States; 4PAIN, McLean Group, Belmont, MA, United States; 5Lilly Research Laboratories, Indianapolis, IN, United States; 6Neurosciences, Merck Research Laboratories, West Point, PA, United States The complexity of the experience of pain is reflected in the functional MRI BOLD response to painful stimuli. Several publications reported on a biphasic BOLD response composed of an early phase closely locked with stimulus time, and a late phase which some have suggested is related to self-assessment of pain. In a placebo controlled study of painful heat, the GLM approach was used to generate quantitative measures and address the issue of sensitivity of these endpoints to Buprenorphine treatment (BUP); with a focus on endpoints related to early, stimulus-locked, and late phase modeled by self-assessment. Najmeh Khalili-Mahani1,2, Remco W. M Zoethout3, Christian F. Beckmann4,5, Evelinda Baerends6, Roelof P. Soeter, 2,6, Marike de Kam3, Mark A. Van Buchem6, Joop M. A. Van Gerven3, Serge A. R .B. Rombouts, 2,6 1Leiden University Medical Center, Department of Radiology, Leiden , Netherlands; 2Leiden Institute for Brain and Cognition, Department of Psychology, Leiden, Netherlands; 3Center for Human Drug Research, Leiden University Medical Center, Leiden, Netherlands; 4Oxford University, Oxford, United Kingdom; 5Imperial College London, London, United Kingdom; 6Leiden University Medical Center, Department of Radiology, Leiden, Netherlands Using state of art pharmacological infusion techniques in a placebo-controlled two-way (treatment by time: 3x7) repeated measure study we show specific and meaningful variations in resting-state brain connectivity in response to dose-controlled administration of morphine and alcohol Najmeh Khalili-Mahani1,2, Mathiass J. P. Van Osch1, Remco W. M Zoethout3, Evelinda Baerends1, Mark A. Van Buchem1, Joop M. A. Van Gerven3, Serge A. R. B. Rombouts1,2 1Leiden University Medical Center, Department of Radiology, Leiden, Netherlands; 2Leiden Institute for Brain and Cognition, Department of Psychology, Leiden, Netherlands; 3Center for Human Drug Research, Leiden University Medical Center, Leiden, Netherlands In a within-subject placebo-controlled pharma-fMRI study, we use pseudo-continuous ASL to show localized and drug-specific changes in CBF in response to dose-controlled infusion of morphine and alcohol. Results correspond to variations observed in the resting-state BOLD fluctuations in the same study. Xiping Liu1, Zheng Yang2, Jun Xie3, Qian Yin1, Shi-Jiang Li1 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 2Beijing Institute of Basic Medical Science, China; 3GE Healthcare, United States Levo-tetrahydropalmatine (l-THP), purified from the Chinese herb, Stephanie, recently has been demonstrated to be effective in attenuating heroin craving and relapse in heroin addicts; it also inhibits cocaine”Æs rewarding effects on animal models. Despite this behavioral evidence, the treatment mechanisms of l-THP for drug addiction have yet to be elucidated. Here, we applied high-field pharmacological MRI (phMRI) on heroin-dependent rats with or without chronic l-THP treatment. We found l-THP significantly attenuates heroin-priming induced BOLD responses in heroin-dependent rats in multiple addiction relevant neural circuitries. 1066. Pharmacological Analysis in Experimental Lung Fibrosis Performed by MRI Anna Louise Babin1, Catherine Cannet1, Christelle Gerard1, Clive P. Page2, Nicolau Beckmann1 1Global Imaging Group, Novartis Institutes for BioMedical Research, Basel, BS, Switzerland; 2Sackler Institute of Pulmonary Pharmacology, King's College, London, SE1 1UL, United Kingdom Experimental studies of lung fibrosis in animals have usually examined the effects of treatments starting before or at the time of lung injury. However, treatment in humans only begins after disease has been established. Since timing of treatment initiation is critical in this chronic model, we used MRI to assess non-invasively the effects of steroids (budesonide and dexamethasone) in the lungs of bleomycin (BLM) treated rats. MRI relying on non-ionizing radiation opens new avenues in testing compounds in vivo as the responses at several time points during the course of treatment can be easily compared. 1067. Tumor-Targeted Imaging and Delivery of SiRNA Zdravka Medarova1, Mohanraja Kumar1, Anna Moore1 1Molecular Imaging Lab, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States Since their discovery in 1998, small interfering RNAs (siRNAs) have emerged as a powerful new tool for post-transcriptional gene silencing. Here, we describe the synthesis and testing of a tumor-targeted nanoparticle probe (MN-EPPT-siSurvivin) to specifically shuttle siRNA to tumor cells. The probe binds the tumor antigen uMUC-1, found on a range of adenocarcinomas, and useful as an imaging target. Human breast, pancreatic, and colorectal cancer cells took up high amounts of the probe. The uptake could be measured by MRI and resulted in significant knock-down of the target gene. Valeria Righi1,2, Caterina Constantinou, 1,3, Dionyssios Mintzopoulos1,2, Nadeem Khan4, Sriram P. Mupparaju4, Harold M. Swartz4, Hazel H. Szeto5, Ronald G. Tompkins6, Laurence G. Rahme3, A Aria Tzika1,2 1NMR Surgical Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States; 2Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, United States; 3Molecular Surgery Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States; 4EPR Center for Viable Systems, Department of Diagnostic Radiology, Dartmouth Medical School, Hanover, NH, United States; 5Department of Pharmacology, Joan and Sanford I. Weill Medical College of Cornell University, New York, NY, United States; 6Department of Surgery, Division of Burn, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States Using P31 NMR and Electron Paramagnetic Resonance (EPR) in vivo, we evaluated the effects of a novel (Szeto-Schiller) SS-31 peptide on ATP synthesis rate and redox status, respectively in a clinically relevant burn trauma model. Our results showed that SS-31 peptide induces ATP synthesis rate and causes recovery of the mitochondrial redox status at 6 hours after burn. Thus, EPR, can be used to complement NMR in investigating, and even validating novel mitochondrial agents for burn trauma and a variety of pathologies (i.e., stroke, heart failure, diabetes, degenerative disorders, trauma, cancer) associated with mitochondrial dysfunction, including normal aging. Frank Risse1, Jelena Pesic1, Simon Young2, Lars E. Olsson1 1DECS Imaging & Antibodies, AstraZeneca R&D, Mölndal, Sweden; 2Bioscience, AstraZeneca R&D, Charnwood, United Kingdom The effect of steroid (budesonide) treatment on lung inflammation in rats caused by ovalbumin can be visualised using hyperpolarised 3He MRI. The aim was to quantify the changes in lung ventilation in this asthma model using texture analysis. Four groups were investigated: controls, vehicle-treated, low and high dose budesonide-treated. First-order texture, geometrical features and features based on second-order statistics using run-length and grey-level co-occurrence matrices were calculated. Additionally, wavelet transforms were applied to compute first-order statistics on multiple scales. The texture analysis showed significant differences between the untreated and the budesonide-treated groups, which was in agreement with a biological marker. Anna Mlynarczyk1, Marco Gruwel2, Piotr Kulinowski1, Krzysztof Jasinski1, Przemyslaw Dorozynski3, Boguslaw Tomanek, 12, Wladyslaw P. Weglarz1 1Department of Magnetic Resonance Imaging, Institute of Nuclear Physics Polish Academy of Sciences, Krakow, Poland; 2Institute for Biodiagnostics, National Research Council of Canada, Winnipeg, Manitoba, Canada; 3Department of Pharmaceutical Technology and Biopharmaceutics, Jagiellonian University, Krakow, Poland MR microscopy was applied for study of water mobility and concentration in tablets, used for drug delivery. The tablets made of Hydroxypropylmethylcellulose-HPMC with and without addition of a drug substance of different solubility (L-dopa and ketoprofen) were tested. Two-dimensional T2 and proton density (PD) maps and their histograms were obtained. Spatial T2 and PD distributions along a tablet radius were also analyzed. Different mechanisms of tablets hydration were observed due to composition of the formulations, eg. for formulation with ketoprofen (low solubility of 0,24 mg/mL) the hydrogel formation was negligible. Deepa Prajapati1, Sundeep Tripathi2, Sanjay Annarao1, Abbas Ali Mahdi2, Mahdi Hasan3, Farzana Mahdi4, Raja Roy1, Chunni Lal Khetrapal1 1CBMR, Centre of Biomedical Magnetic Resonance, Lucknow, Uttar Pradesh, India; 2CSM Medical University; 3Anatomy, CSM Medical University; 4Era's Lucknow Medical College Prolonged aluminium insults results in oxidative damage leading to hepato and nephrotoxicity in rats.1H NMR study of rats serum and urine have been utilized to evaluate the comparative protective effects of Bacosides and Donepezil drugs over continuous Aluminium- induced metabonomic changes. Bacosides was found to markedly attenuate the oxidative stress induced by Aluminium over long term (90 days) dose compared to Donepezil. This might be interpretated in terms of strong antioxidative property of Bacosides compared to Donepezil. The study suggests that 1H NMR metabolic profiling is an efficient method to explore the efficacy of potent molecules over metal toxicity.
1072. Effect of Varenicline on BOLD and Neural Networks in Awake Animals Wei Chen1, Joseph R. DiFranza2, Jean King3 1Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, , United States; 2Department of Family Medicine and Community Health,, University of Massachusetts Medical School, Worcester; 3Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, United States Tobacco dependence is the most preventable cause of death. Varenicline is a partial nicotinic receptor agonist/antagonist that is widely used as a smoking cessation aid. How varenicline helps smokers is unknown. We sought to compare the brain Blood oxygenation level dependent (BOLD) activation produced by a high dose varenicline to a lower dose varenicline in awake naļve animals, which hopes to assist in understanding the action of this partial nicotinic receptor agonist/antagonist in patients. Outcomes: Cost Effectiveness etc. Hall B Thursday 13:30-15:30 1073. The EMITEL Multilingual Dictionary: A New Resource for the Global MRI Community Stephen Frederick Keevil1,2, Gerard Boyle3, Emil Lindholm4, Franco Milano5, Freddy Stahlberg4, Ronnie Wirestam4, Slavik Tabakov2, Andrew Simmons6 1Medical Physics, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom; 2Imaging Sciences, King's College London, London, United Kingdom; 3St James's Hospital, Dublin, Ireland; 4University of Lund, Lund, Sweden; 5University of Florence, Florence, Italy; 6Centre for Neuroimaging Sciences, King's College London, London, United Kingdom A mutilingual dictionary of terms used in MRI and other medical physics specialties has been developed by an international network of over 200 physicists and engineers. The dictionary (available free at www.emitel2.eu) allows translation of terms between 25 languages, with extension to additional languages planned for the future. The software platform was developed to be as simple as possible without compromising content, allowing easy update and maximising longevity. The dictionary can be used as a free-standing resource or as a portal to an e-encyclopaedia of medical physics. Together, the dictionary and encyclopaedia are valuable resources for the worldwide MRI community. Patrick C. Hettinger1, Rupeng Li2, Ji-Geng Yan1, Hani S. Matloub1, Young R. Cho1, Matthew L. Runquist2, Christopher P. Pawela1,2, James S. Hyde2 1Plastic Surgery, Medical College of Wisconsin, Milwaukee, WI, United States; 2Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States The purpose of this study is to develop a rodent survival model that enables fMRI at multiple time-points under sedation. In this study, 9 Sprague-Dawley rats underwent surgical placement of a long-term vascular access port. The animals were then imaged using fMRI during nerve stimulation at 1 week, 3 weeks, and 5 weeks post-operatively. During imaging, all animals breathed spontaneously while intravenous sedative was administered through the port. To date, all animals have successfully been imaged at each time-point. All vascular access ports have remained patent, making these devices a viable option for longitudinal MRI studies requiring venous access. 1075. A Low-Cost Experimental Set-Up for Functional Magnetic Resonance Imaging Carolina Arboleda1,2, Cristiįn Andrés Tejos1,2, Sergio Uribe, 2,3, Francisco Zamorano4, Francisco Aboitiz4, Pablo Irarrazaval1,2 1Electrical Engineering Department, Pontificia Universidad Católica de Chile, Santiago, Chile; 2Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Chile; 3Radiology Department, Pontificia Universidad Católica de Chile, Santiago, Chile; 4Cognitive Neuroscience Laboratory, Pontificia Universidad Católica de Chile, Santiago, Chile An fMRI setup for stimuli presentation, should include a coupling circuit to connect the MR-scanner output pulse to the computer that presents the stimuli (scanner trigger detector, STD), and a Response-Detection Pad (RDP) which needs to be placed inside the scanner and, thus, can not contain any ferromagnetic materials. Currently, there are several RDC and STD commercially available, but their cost is significantly high (~3,000 USD + shipment). Here, we propose a cheap (~155 USD + shipment) setup that includes a fiber optic RDP and a photo coupler-based STD, and is compatible with current scanners and fMRI software. Honglei Zhang1, Giles H. Roditi2, Tim Leiner3, Walter Kucharczyk4, Martin R. Prince1 1Radiology, Weill Medical College of Cornell University, New York, NY, United States; 2Radiology, Glasgow Royal Infirmary, Scotland; 3Maastricht University Hospital, Netherlands; 4University of Toronto, Toronto, Ontario, Canada Concern about the association between GBCA and NSF has led to widespread screening of MRI patients for renal dysfunction and withholding GBCA when GFR is < 30 mL/min. Analysis of 78 retrospective case series reporting 292 NSF cases explores the risk factors for NSF. Elimination of multiple risk factors by using single dose GBCA, dialyzing dialysis patients quickly following GBCA administration, avoiding GBCA in acute renal failure while serum creatinine is rising, and avoiding non-ionic linear GBCA in renal failure patients, may reduce NSF risk more than a thousand fold, thereby allowing safe GBCA enhanced MRI in virtually all patients. fMRI Acquisition Hall B Monday 14:00-16:00 1077. Separating FID and Echo Contribution in Pass-Band BSSFP FMRI with Multiple-Phase Angle Cycling Sung-Hong Park1,2, Tae Kim1, Ping Wang1, Timothy Q. Duong2, Seong-Gi Kim1 1Radiology, University of Pittsburgh, Pittsburgh, PA, United States; 2Research Imaging Institute, Ophthalmology/Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States We acquired high resolution multiple phase-cycled bSSFP fMRI datasets in rat brains at 9.4T and separated FID and main echo components based on Fourier analysis. The FID component showed stronger fMRI signals than the main echo component, but it showed stronger correlation with both intracortical veins and cortical surface veins. The fMRI signal from the main echo component could contribute up to half of that from the FID component, implying that the main echo component should not be neglected in interpreting pass-band bSSFP fMRI signals. Mark Chiew1,2, Simon James Graham1,2 1Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 2Rotman Research Institute, Toronto, Ontario, Canada The use of multi-echo imaging techniques for contrast enhancement in BOLD fMRI is gaining momentum, particularly in real-time fMRI applications. A novel method is presented for combining multi-echo signals in weighted summation using principal component analysis (PCA) derived weights. The method is evaluated on human volunteers performing a simple motor task at 1.5 T, and is compared to other reported weighting schemes. The data driven PCA weighting method is demonstrated to produce time-series that achieve high relative contrast-to-noise ratio gain, without requiring additional data collection. 1079. Variable Density Spiral FMRI Catie Chang1, Gary Harold Glover1 1Electrical Engineering & Radiology, Stanford University, Stanford, CA, United States We propose a novel variable-density (VD) spiral k-space trajectory for brain fMRI. The trajectory consists of an Archimedean spiral from the origin out to an arbitrary radius k1, extending beyond k1 with a spiral in which the sampling density decreases as the k-space radius increases. Thus, it allows for a reduction in readout time at the expense of undersampling only high spatial frequencies. We implemented the VD spiral in a single-shot 2D spiral-in/out sequence for high (128x128) resolution, and demonstrate improved activation in a sensory-motor task compared to conventional (fully Archimedean) single-shot and interleaved sequences. 1080. High Resolution BOLD FMRI Using MHASTE Yongquan Ye1, Yan Zhuo1, Xiaohong Joe Zhou2 1State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics,CAS, Beijing, China; 2University of Illinois Medical Center, Chicago, IL, United States High resolution BOLD fMRI data on visual cortex were acquired using mHASTE, a novel GRAPPA accelerated single shot TSE technique, and the results were compared with those of GE- and SE-EPI. Higher SNR was obtained with mHASTE than both EPIs, and increased functional activation was detected by mHASTE but not by EPI when going from low resolution to high resolution. mHASTE was also found to have greater activation than both EPI in some cases,especially at high resolution, suggesting a more robust BOLD contrast mechanism for mHASTE in high resolution fMRI. 1081. Functional Magnetic Resonance Imaging Using PROPELLER EPI Martin Krämer1, Thies Halvor Jochimsen1, Marc Roth1, Jürgen Rainer Reichenbach1 1Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital, Jena, Germany A method to improve spatial and temporal resolutions in fMRI using PROPELLER-EPI. First results are shown which demonstrate that a sliding window reconstruction of high resolution long-axis propeller (LAP) data is suitable for simple fMRI experiments. Additionally the results achieved by the LAP measurements are compared to the standard 64x64 EPI sequence which is usually used in fMRI. From there it is shown that the activation maps created from the LAP scans are better localized along the cortex. 1082. Passband BSSFP: Functional Contrast Compared to GRE-EPI and SE-EPI at 3T. Pål Erik Goa1, Anders Kristoffersen1, Michael H. Chappell2, Rob H. Tijssen3, Asta K. Håberg4, Karla L. Miller3 1Dept. of Medical Imaging, St. Olavs University Hospital, Trondheim, Norway; 2Dept. of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 3FMRIB Centre, Oxford University, Oxford, Oxon, United Kingdom; 4Dept. of Neuromedicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway The functional contrast in passband balanced steady-state free precession (pbSSFP) with 3D segmented EPI readout is compared to that of GRE-EPI and SE-EPI at 3T. For pbSSFP, TR is varied from 6.5 ms to 45 ms. Standard flickering checkerboard paradigm is used. We find that the best functional contrast is obtained at TR = 33 ms with corresponding EPI-factor of 40. At this TR, the functional contrast in pbSSFP is approximately half that of GRE-EPI and twice that of SE-EPI with otherwise comparable scan parameters. False detections due to banding artefacts are present in pbSSFP. 1083. Isotropic Sub-Millimeter FMRI in Humans at 7T Robin Martin Heidemann1, Dimo Ivanov1, Robert Trampel1, Joeran Lepsien1, Fabrizio Fasano2, Josef Pfeuffer3, Robert Turner1 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2Fondazione Santa Lucia, Rome, Italy; 3Siemens Healthcare Sector, Erlangen, Germany For isotropic high resolution fMRI at ultra-high field strength, susceptibility effects and T2* decay must be properly addressed. A combination of reduced FOV imaging (zoomed imaging) and parallel imaging is optimized here, achieving acceleration factors of up to 5.5. The high acceleration reduces distortions and image blurring, while incurring no other image artifacts. With this approach, high quality single-shot EPI acquisitions can be obtained with an isotropic resolution of 0.65 mm and sufficient coverage for e.g. fMRI in the visual cortex of the human brain. Thomas Sushil John1, Michael Lustig2,3, John Mark Pauly2 1Electrical Engineering , Stanford University, Stanford, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States; 3Electrical Engineering and Computer Science, UC Berkeley, Berkeley, CA, United States Echo planar imaging (EPI) is the most widely used method for functional MRI. However, functional images are often distorted because EPI is highly sensitive to field inhomogeneities, eddy currents, and gradient delays. Functional and neuro-anatomical registration is complicated by these distortions and by the fact that functional and anatomical images are usually obtained with different imaging sequences. This work investigates the use of an optimized 3D flyback EPI trajectory with echo time shifting to obtain functional and anatomical images that have minimal distortions and are inherently co-registered. Kimberly Brewer1,2, James Rioux1,2, Martyn Klassen3, Chris Bowen1,4, Steven Beyea1,4 1Institute for Biodiagnostics (Atlantic), National Research Council of Canada, Halifax, Nova Scotia, Canada; 2Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada; 3Robarts Research Institute, University of Western Ontario, London, Ontario, Canada; 4Physics and Atmospheric Science, Radiology and Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada Spiral pulse sequences are commonly used in fMRI, and spiral-in is known to be considerably better than spiral-out at signal recovery in regions with strong susceptibility field gradients. Previously proposed theories in the literature do not address the probability of signal displacement or fully explain all of the differences in signal recovery between spiral-out and spiral-in. In the current work we demonstrate that the difference in image intensity is not due to differences in signal displacement between spiral-in and spiral-out, but rather the increased phase coherence of the displaced pixels when using spiral-in. 1086. Mitigating the Effects of Motion in EPI Time Series John M. Ollinger1, Andrew L. Alexander1 1Waisman Laboratory for Brain Imaging, University of Wisconsin, Madison, WI, United States A model for image variance due to motion is developed and validated. It can be used minimize motion effects by optimizing EPI sequence parameters. In general, variance is minimized by minimizing the partial derivative of the steady-state magnetization along the slice axis. In particular, sidelobes contribute much of the noise at high flip angles; an optimum flip angle exists for a specified degree of motion and can be computed; and inter-slice gaps increase variance due to motion rather than decrease it. 1087. Quantitative Evaluation of FMRI Acquisition Strategies at 7T Using NPAIRS Robert L. Barry1,2, J Christopher Gatenby1,2, Allen T. Newton1,2, Stephen C. Strother3,4, John C. Gore1,2 1Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 2Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; 3Rotman Research Institute of Baycrest, Toronto, ON, Canada; 4Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada Although 2D single-shot EPI is common in BOLD fMRI, recent studies have suggested that 3D multi-shot sequences such as PRESTO-SENSE may offer superior BOLD CNR through improved temporal efficiency. A four-way comparison was performed between 2D and 3D acquisition sequences at two voxel resolutions (1.19x1.19x2 mm3 and 2.19x2.19x2 mm3) at 7T. The quality of fMRI data was evaluated via independent and unbiased metrics of prediction and reproducibility using NPAIRS. Results suggest that EPI provides higher prediction and reproducibility for this study. Future work will investigate within-subject optimization, and further compare EPI with PRESTO-SENSE for an fMRI study requiring whole-brain coverage. 1088. The Effect of Parallel Imaging on the Sensitivity of BOLD Signal to Physiological Noise Tomas Jonsson1, Tie-Qiang Li1 1Department of Medical Physics, Karolinska University Hospital, S-141 86, Stockholm, Sweden The sensitivity to physiological noises of the reconstructed BOLD MR images is altered by the employed parallel imaging strategies. In this study, we mapped and compared the physiological noise sensitivity of BOLD fMRI data acquired with and without employing parallel imaging at two different spatial resolutions. Using higher spatial resolution reduces the signal strength and the relative sensitivity to physiological noise. This can be of SNR advantage particularly for time series fMRI data acquired at higher magnetic field. 1089. Multi-Slice Two- And Four-Fold Acceleration with Single- And Eight-Channel Coils, Respectively Andrzej Jesmanowicz1, Shi-Jiang Li1, James S. Hyde1 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States Complex-valued tailored pulses have been used in an EPI sequence to excite two or more slices in human brain using a whole-brain transmit coil. One or more members of a receive-coil array have been used to acquire multi-channel image data. Complex-valued coil profiles have been used to recover slices, and parallel image formation has been demonstrated. Acceleration by a factor of 4 has been achieved with an eight-channel head coil. Rupeng Li1, Patrick Hettinger2, Younghoon Cho1, Christopher P. Pawela1, Ji-Geng Yan2, Andrzej Jesmanowicz1, Anthony Hudetz3, Hani Matloub2, James Hyde1 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 2Plastic Surgery, Medical College of Wisconsin, Milwaukee, WI, United States; 3Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States Single-shot half k-space GR-EPI sequence was used to push the BOLD imaging resolution to 300 micron cubic voxel and unique single column cortical activation in the sensory cortex was detected when stimulating the middle phalange of all 8 digits of rat. 1091. Development and Evaluation of Alternative Imaging Methods for FMRI at 7 Tesla John Sexton1,2, Jascha Swisher3, Frank Tong3, Baxter Rogers1,2, J Christopher Gatenby1,4, John C. Gore1,4 1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States; 2Biomedical Engineering, Vanderbilt University, Nashville, TN, United States; 3Psychology, Vanderbilt University, Nashville, TN, United States; 4Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States We compare single-shot gradient-echo 2D-EPI, multi-shot gradient-echo 3D-FFE and multi-shot gradient-echo 3D-PRESTO in a polar angle retinotopic mapping experiment at four isotropic resolutions (1.12mm3, 1.67mm3, 2mm3, and 3mm3) at 7 Tesla. Retinotopic maps in agreement with literature were obtained at all resolutions. The 3D sequences provided similar BOLD sensitivity and significantly less distortion compared to 2D-EPI. In addition, 3D-PRESTO provided much higher temporal resolution than 2D-EPI. Our findings suggest rich potential for high-resolution 3D imaging sequences in retinotopic mapping and other functional MRI experiments at high field. 1092. What Is the Optimum FMRI Procedure with Auditory Stimulation? Karsten Mueller1, Toralf Mildner1, Tom Fritz1, Joeran Lepsien1, Christian Schwarzbauer2, Harald E. Möller1 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2Aberdeen Biomedical Imaging Centre, University of Aberdeen, United Kingdom To present auditory stimuli in the absence of scanner noise, the sparse temporal sampling (STS) approach was introduced. The interleaved-silent steady-state (ISSS) technique is combining the idea of splitting image acquisition and stimulus presentation with a better sampling of the fMRI signal. We performed an auditory experiment with pleasant and unpleasant stimuli using four fMRI sessions: STS, ISSS, and simultaneous stimulus presentation and image acquisition with axial and sagittal scanning. The total acquisition time was the same in all four sessions. The best sensitivity for detecting activations of sub-cortical regions (such as the amygdala) was found for ISSS. 1093. Feasibility of BOLD Magnetic Resonance Imaging of Lung Tumors at 3T Qing Yuan1, Yao Ding1, Rami R. Hallac1, Paul T. Weatherall1, Robert Doug Sims1, Thomas Boike2, Robert Timmerman2, Ralph P. Mason1 1Radiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, United States; 2Radiation Oncology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, United States It is expected that BOLD MRI should be sensitive to tumor vascular oxygenation. In lung tumors BOLD MRI is challenging due to potential image artifacts from motion, blood flow, and susceptibility. The goal of this preliminary study was to optimize the BOLD imaging technique at 3T in patients with untreated lung cancer. A respiratory-gated multi-echo gradient-echo technique is demonstrated as a feasible method to quantify T2* values of lung tumors. The response of tumor T2* measurements to an oxygen-breathing challenge should be sensitive to tumor hypoxia and could therefore serve as a prognostic indicator before therapy. Yao Ding1, Ralph P. Mason1, Qing Yuan1, Rami R. Hallac1, Roderick W. McColl1, Robert D. Sims1, Paul T. Weatherall1 1Radiology, UT southwestern medical center at Dallas, Dallas, TX, United States The present 2D respiratory-triggered interleaved T1- and T2*-weighted sequence provides a promising means to study TOLD and BOLD response simultaneously without the need for registration and with good temporal resolution (less than 30 seconds). 1095. Does the BOLD Response to EPI-Related Acoustic Noise Change Over an FMRI Experiment? Oliver Hinds1, Aaron Hess2, M. Dylan Tisdall3, Todd Thompson1, Hans Breiter3, André van der Kouwe3 1A. A. Martinos Imaging Center at the McGovern Institute, Massachusetts Institute of Technology, Cambridge, MA, United States; 2Human Biology, University of Cape Town, Cape Town, South Africa; 3A. A. Martinos Center for Biomedical Imaging, Department of Radiology, MGH, Harvard Medical School, Charlestown, MA, United States If the BOLD response to EPI acoustic noise changes over the time course of a standard fMRI experiment, both Type I and Type II errors can be made in fMRI group analysis. We used a pulse sequence based on single-voxel functional spectroscopy to silently measure the BOLD response induced by EPI-like scanner noise over about 40 minutes. No significant habituation or facilitation with respect to the scanner noise was found over that time. This result eliminates a possible confound for auditory and speech neuroimaging studies, especially those involving learning. 1096. Reproducibility of FMRI Localisation Within the Human Somatosensory System. Rishma Vidyasagar1, Laura M. Parkes2,3 1MARIARC, University of Liverpool , Liverpool, Merseyside, United Kingdom; 2School of Cancer and Imaging Sciences, University of Manchester; 3Biomedical Imaging Institute, University of Manchester, Manchester, United Kingdom fMRI data can often be affected by issues such as registration and scanner system errors. These issues affect interpretation of data and is especially relevant in longitudinal studies depending on accurate reproducibility of data. This study compared different analysis techniques of fMRI data to establish the most accurate means of overcoming these issues by focusing on fMRI data from the somatosensory system in the human brain. 1097. Real Time FMRI Avoiding Drift Using Answer Blocks Thomas WJ Ash1, T Adrian Carpenter1, Guy B. Williams1 1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom Where real time fMRI needs solely a digital (e.g., task vs rest or task 1 vs task 2) output, answer blocks can provide a means of circumventing the drift that is known to affect results. Using answer blocks, we improve performance compared to averaging over a block using classifiers from 53% to 84%, and using ROI techniques from 53% to 64%. This also gives a means for presenting probabilistic outputs to class membership, which are vital when dealing with impaired patients, for whom this kind of technique may be their only communication channel. 1098. Simultaneous Optical Tomography (OT) and FMRI with and Without Task Activation Jan Mehnert1,2, Christoph Schmitz2,3, Harald E. Möller1, Hellmuth Obrig1,2, Karsten Müller1 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2Berlin Neuroimaging Center, Charité University Hospital Berlin, Berlin, Germany; 3NIRx Medizintechnik GmbH, Berlin, Germany Correlation analysis of low-frequency fluctuations in blood-oxygen level dependent (BOLD) fMRI data is known to yield functional connectivity maps. The procedure, also referred to as resting-state connectivity, has previously been applied to optical tomography (OT) data using dense probe arrays. Here, we assess whether a sparser topographical sampling still yields results that are comparable to the gold standard of resting-state network assessment, i.e. fMRI. In a first step, we used a subset of optical fibers (2-3cm inter-optode distance) covering both motor cortices and combined OT with concurrent fMRI measurements to cross-validate our resting-state data analysis. 1099. High Resolution Functional MR Venography with 7T MRI Seo-Hyun Lee1, Chang-Ki Kang1, Chan-A Park1, Young-Bo Kim1, Zang-Hee Cho1,2 1Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea, Republic of; 2Department of Radiological Sciences, University of California, Irvine, Irvine, CA, United States MR venography using susceptibility weighted imaging (SWI) has been utilized for the study of venous morphology and the venous vasculature in disease states. However, SWI has poor intrinsic temporal resolution, thus it is not able to provide information on high temporal dynamic changes within a few seconds that occur during neural stimulation. In this paper, we proposed a technique, which we labeled functional MR venography (fMRV), to investigate the venous dynamic response to external stimulation using 7T MRI. The presented result suggests that this technique may provide important, more precise information regarding the venous response and its role in the overall hemodynamic response to neural activity with high spatial (0.5 isotropic) and temporal (3 seconds) resolution. 1100. The Orbitofrontal FMRI Experiment with Correction of the Susceptibility Artifact Sung Suk Oh1, SungDae Yun1, Bumseok Jeong2, HyunWook Park1 1Department of Electrical Engineering, KAIST, Daejeon, Korea, Republic of; 2Department of Psychiatry, Eulji University Hospital, Daejeon, Korea, Republic of The signal loss by the susceptibility artifact makes it difficult analyze the fMRI data of the orbitofrontal region of the brain. In addition, an EPI sequence, which is used in many fMRI experiments, has the geometric distortion and Nyqust ghosts. For the fMRI experiment with correction of these artifact and distortion, we used a flat RF pulse which provides nearly constant signal intensity against the magnetic susceptibility and a gradient echo sequence. In the result, it is shown that the signal loss in the orbitofrontal region of the brain is recovered without geometric distortion and Nyqust ghosts and the activation in that region was analyzed successfully. Peter Dechent1, Rafael Polania2, Carsten Schmidt-Samoa1, Walter Paulus2, Andrea Antal2 1MR-Research in Neurology and Psychiatry, University Göttingen, Göttingen, Germany; 2Department of Clinical Neurophysiology, University Göttingen, Göttingen, Germany Anodal/cathodal tDCS have facilitatory/inhibitory effects, respectively, on the stimulated cortical networks. Here we used concurrent tDCS-fMRI to test whether anodal/cathodal tDCS result in BOLD-fMRI signal changes during a resting condition. Furthermore, we examined tDCS-effects on brain activation during voluntary finger tapping. Anodal/cathodal tDCS over left M1 induced no detectable BOLD signal change. However, anodal/cathodal tDCS combined with finger tapping resulted in a decreased BOLD response in SMA, but not M1, in comparison to voluntary finger tapping without stimulation. This suggests that in contrast to the rest condition the combination of neuronal polarization and motor activation induces inhibition in remote brain areas. 1102. High-Resolution Fingersomatotopy at 7T Using HGS-Parallel Technique SungDae Yun1, Jun-Young Chung2, Hyo Woon Yoon3, Zang-Hee Cho3, HyunWook Park1 1Department of Electrical Engineering, KAIST, Daejeon, Korea, Republic of; 2Neuroscience Research Institute, Gachon University of Medicine and Science , Incheon, Korea, Republic of; 3Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea, Republic of In a high field MRI, improvements in SNR and image quality are very noticeable, even though there are some drawbacks such as increased field inhomogeneity and relatively short T2*. For EPI-based methods, these drawbacks are major challenges in performing fMRI. To reduce such problems, we employed the HGS-Parallel technique as an fMRI imaging method which used the conventional gradient echo. This sequence is relatively robust to field inhomogeneity and the T2* decay than the EPI. With the HGS-Parallel technique, we performed an fMRI experiment at a 7T for mapping the finger somatosensory area in a high quality and resolution form. Mikhail Zvyagintsev1,2, Yury Koush3, Miriam Dyck3, Klaus Mathiak3 1IZKF, RWTH Aachen University, Aachen, NRW, Germany; 2Psychiatry, RWTH Aachen University, Aachen, NRW, Germany; 3Psychiatry, RWTH Aachen University, Germany Biofeedback based on a real-time fMRI is a promising tool especially in clinical research. In this study we show feasibility of controlling the left middle frontal gyrus by using mental imagery strategy. 1104. Sensitivity and Spatial Specificity of Multiple Phase-Cycled Pass-Band BSSFP FMRI at 9.4T Sung-Hong Park1,2, Tae Kim1, Ping Wang1, Timothy Q. Duong2, Seong-Gi Kim1 1Radiology, University of Pittsburgh, Pittsburgh, PA, United States; 2Research Imaging Institute, Ophthalmology/Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States We performed high-resolution pass-band bSSFP fMRI at multiple phase cycling angles on rat brain at 9.4T. Activation foci in fMRI maps shifted as a function of phase cycling angle and the location of the foci was correlated with hyperintense regions in corresponding baseline transition-band bSSFP, some of which were also correlated with cortical surface veins or intracortical veins. The results indicated that there is spatial heterogeneity in signal sources (T2 or T2*) of pass band bSSFP fMRI. Baseline transition band bSSFP could be used to predict outcomes of corresponding pass-band bSSFP fMRI maps. 1105. Interleaved TMS/CASL: State Dependence of Repetitive TMS Effects on the Dorsal Premotor Cortex Marius Moisa1, Rolf Pohmann1, Hartwig Roman Siebner2, Axel Thielscher1 1Max Planck Institute for Biological Cybernetics, Tübingen, BW, Germany; 2Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark We have recently demonstrated the technical feasibility and the potential advantages of combining transcranial magnetic stimulation (TMS) with continuous arterial spin labeling (CASL) imaging. Here, we use this novel approach to assess the effects of repetitive TMS applied to the left dorsal premotor cortex (PMd) on rCBF (regional cerebral blood flow) during different motor states. The state-dependent effects of left PMd rTMS on rCBF, is in concordance with previous results using BOLD imaging and a different task. As a next step, we will analyze the time dependence of the observed TMS effects across the different experimental blocks of one run. 1106. Development of Simulator Training to Reduce Head Motion Artifact in FMRI Shawn Ranieri1,2, Shaun Boe3, Fred Tam1, Lauren Gordon4, Tara Dawson1, Jon Ween5, William McIlroy6, Simon J. Graham1,7 1Rotman Research Institute, Baycrest Centre for Geriatric Care, Toronto, ON, Canada; 2Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; 3Toronto Rehabilitation Institute, Toronto, ON, Canada; 4Faculty of Health Sciences, Queen's University, Kingston, ON, Canada; 5Kunin-Lunenfeld Applied Research Unit , Brain Health Complex, Toronto, ON, Canada; 6Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Waterloo, ON, Canada; 7Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada There has been a longstanding need to develop techniques that improve data quality in fMRI by suppressing motion artifact. Head motion exceeding a few millimetres remains problematic and high interest participants including motor stroke patients often exceed this threshold. Here, a new technique is described that attempts to reduce participant head motion through visual feedback training in an fMRI simulator. Results from three stroke patients show that simulator training had a significant effect in suppressing head motion: (1) 11.25 mm before, 0.83 mm after; (2) 1.63 mm before, 0.67 mm after; (3) 4.47 mm before, 0.51 mm after. 1107. Scan Time Reduction in FMRI Using a 32 Channel Phased Array Receive Coil Christina Triantafyllou1,2, Sheeba Arnold1, Steven Shannon1, John Gabrieli3, Susan Whitfield-Gabrieli3 1A.A. Martinos Imaging Center, McGovern Institute for Brain Research, MIT, Cambridge, MA, United States; 2A.A. Martinos Center for Biomedical Imaging, Department of Radiology, MGH, Charlestown, MA, United States; 3Department of Brain and Cognitive Sciences, MIT, Cambridge, MA, United States Long durations in fMRI are typical, but that is unfeasible for specific populations. Scan-time reduction is possible if one could capitalize on the increased sensitivity afforded by high field strength or multiple channel phased arrays in the high-resolution regime. We evaluated this using a 32-channel coil at 3T with the n-back task on 18 subjects. Compared to 12-channel coil, working memory activation was significantly more (paired t-test) with two-thirds of the 32-channel data. Combination of 32-channel coil and high-resolution could imply lesser sample size, prevent additional data collection and enable studies that would otherwise be impossible due to time restrictions. 1108. Multi-Sequence Comparison of Temporal Lobe FMRI Activation at 4.0 T Lindsay Cherpak1,2, Kimberly Brewer1,2, Jodie Gawryluk1,3, Nicole Pelot1,2, Chris Bowen1,4, Ryan D'Arcy1,3, Steven Beyea1,4 1Institute for Biodiagnostics (Atlantic), National Research Council of Canada, Halifax, Nova Scotia, Canada; 2Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada; 3Psychology, Dalhousie University, Halifax, Nova Scotia, Canada; 4Physics and Atmospheric Science, Radiology and Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada This study involved a comprehensive evaluation of commonly-used techniques like EPI and spiral-out, as well as techniques designed to recover signal in SFG regions using BOLD methods (spiral-in, spiral-in/out, spiral-in/in and ASE spiral) and non-BOLD methods (FAIR and spin-echo spiral-in/out) at 4.0 T. A cognitive task used to evaluate temporal lobe epilepsy patients was presented to elicit activation in the inferior temporal lobe (as well as other brain regions). Notably, this work allowed us to examine the differing effects that the contrast and signal recovery mechanisms have on fMRI activation in both SFG and non-SFG regions. 1109. Time Resolved FMRI: 100 Ms Resolution in Time for Extended Network Analysis of the Human Brain Julia Reinhardt1,2, Ernst Nennig3, Stephan Walther4, Sabine Heiland2, Christoph Stippich1,2 1Department of Neuroradiology, University of Basel Hospital, Basel, Switzerland; 2Division of Neuroradiology, Department of Neurology, University of Heidelberg, Medical Center, Heidelberg, Germany; 3OptiMed Medizinische Instrumente GmbH, Ettlingen, Germany; 4Center for Psychosocial Medicine, General Psychiatry, University of Heidelberg, Medical Center, Heidelberg, Germany Until now the temporal resolution in fMRI was mostly restricted by the used TR. Employing a new method to enhance the time resolution in fMRI below 100 ms we are able to trace neuronal network pathways with extremely short reaction times. The temporal dynamics of somatosensory processing could be measured and correspond with the known values from electrophysiological measures. With this new approach BOLD-fMRI enables to study the temporal dynamics of cortical processing with a temporal resolution of 10 ms. 1110. Evaluating Feraheme as a Potential Contrast Agent for Clinical IRON FMRI Joseph B. Mandeville1, Krishna Srihasam2, Wim Vanduffel1, Margaret S. Livingstone2 1Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States; 2Department of Neurobiology, Harvard Medical School, Boston, MA, United States Feraheme is a newly FDA-approved drug for treating chronic iron anemia in clinical populations. The approved iron dose of 510 mg falls within a weight-normalized range of 5-10 mg/kg for human subjects within the range 50-100 kg. To evaluate this drug as a potential contrast-enhancing agent for human clinical fMRI, we performed experiments in awake non-human primates at 3 Tesla to validate theoretical calculations. Results suggest that this agent could enhance the CNR ratio of clinical fMRI by factors of 5 and 2.5 and 1.5 at 3 Tesla, respectively. Wanyong Shin1, Hong Gu1, Yihong Yang1 1Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States Recently, FRActional Signal mapping from InvErsion Recovery (FRASIER) was proposed to map T1 and tissue fractional volume in the brain. In this study we incorporated FRASIER into an fMRI protocol and assessed the reproducibility of the technique. Using FRASIER, 15 slice T1 and fractional volume maps were acquired in every 10 seconds with 64”æ64 matirx size. Standard deviations of the T1 and fractional volume maps was within 37ms and 3.5% in this study, demonstrating feasibility of FRASIER in fMRI settings. Elsmarieke van de Giessen1, Paul F.C. Groot2, Jan Booij1, Wim van den Brink3, Dick J. Veltman3, Aart J. Nederveen2 1Nuclear Medicine, Academic Medical Center, Amsterdam, Netherlands; 2Radiology, Academic Medical Center, Amsterdam, Netherlands; 3Amsterdam Institute for Addiction Research, Academic Medical Center, Amsterdam, Netherlands This study is the first, to our knowledge, that tests the feasibility of fMRI on an open MRI system, with a magnetic field strength of 1.0 T, and compares the results with fMRI on a state-of-the-art 3.0 T MRI scanner. The optimal echo time for fMRI on an open 1.0 T MRI system was found to be around 70 ms. Results show that fMRI on an open 1.0 T MRI scanner is feasible for studies that are designed to analyze data at a group level, though not optimal for studies on single subjects. fMRI Modeling & Signal Characteristics Hall B Tuesday 13:30-15:30 1113. An EEG Homologue of the Negative BOLD Response as Measured at 7 Tesla Wietske van der Zwaag1,2, Marzia De Lucia3, Nadine Graedel2, Micah M. Murray3, Rolf Gruetter1,2 1Radiologie, Université de Lausanne, Lausanne, Vaud, Switzerland; 2CIBM, EPFL, Lausanne, Vaud, Switzerland; 3Electroencephalography Brain Mapping core, CHUV, Lausanne, Vaud, Switzerland The basis of fMRI experiments is a tight coupling of neural activity with the BOLD response in both space and time. However, cross-modal negative BOLD signal may also be caused by blood-steal effects. Here, we measure the negative BOLD signal using ultra-high field fMRI and the neuroelectrical activity as measured by EEG in the same subjects. Neural deactivation is found in the EEG-based electrical neuroimaging maps in regions partially overlapping with those where the negative BOLD signal is found, implying a possible neural basis for the negative BOLD response. 1114. Substantial Flow-Related Contribution in FMRI Signal Observed in Human Visual Cortex at 4T Xiao Wang1, Wei Chen1 1Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States It is a common practice to apply a short repetition time (TR) for acquiring more fMRI volumes within a given total imaging time, thus gaining contrast-to-noise ratio (CNR). However, both the task-evoked BOLD (T2/T2*) effect and flow-related component (R1) increases could contribute to the total percentage change of fMRI signal. This study aims to quantitatively evaluate the BOLD and flow contributions in the fMRI signal detected by gradient echo EPI in the human visual cortex during visual stimulation at 4T. The results show a substantially large flow-related contribution in the measured fMRI signal when TR is short. The observed flow-related enhancement in fMRI signal is likely attributed by perfusion change, and it benefits fMRI mapping in two aspects: improved CNR and specificity. The finding also suggests that the flow-related component needs to be considered in BOLD quantification (e.g., calibration of CMRO2). 1115. Compromised Temporal Responsivity in Fusiform Areas by Aging Makoto Miyakoshi1, Annabel Shen-Hsing Chen2, Kayako Matsuo3, Toshiharu Nakai 1National Center for Geriatrics and Gerontology, Ohbu, Aichi, Japan; 2Nangyang Technorogical University; 3National Taiwan Univsersity To study the aging effect on neural mechanism of visual repetition, we performed an fMRI study. Participants saw inside and outside scenes repeatedly for five blocks, and the first two blocks (eight repetitions for each scene) were compared with the last two blocks for Young and Elderly groups. The results showed that the Elderly group has longer time-constant for the visual repetition effect to take place within fusiform areas and the occipital cortex. The results supported the conclusion that the aging effect on visual repetition is represented by the compromised slew rate i.e., temporal responsivity in the fusiform gyri. Chao-Chun Lin1,2, Yi-Jui Liu3,4, Chien-Kuo Chen3, Hsiao-Wei Peng3, Kuo-Fang Shao4, Wu-Chung Shen1,5, Chang Hing-Chiu6 1Department of Radiology, China Medical University Hospital, Taichung, Taiwan, Taiwan; 2Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, Taiwan; 3Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan; 4Master's Program in Biomedical Informatics and Biomedical Engineering, Feng Chia University, Taichun, Taiwan; 5School of Medicine, China Medical University, Taichung, Taiwan; 6Applied Science Laboratory, GE Healthcare Taiwan, Taipei, Taiwan The purpose of this study was to evaluate the hemodynamic response function (HRF) change after inhalation of different carbon dioxide concentrations. Using event-related method investigate the transient hemodynamic response function by short-time visual stimulus with different CO2 concentrations. Our results show that the peak of HRF curve is decreased and delayed with increased inhaled CO2 concentrations, and the width of HRF curve is wider with higher inhaled CO2 concentration. Farshad Moradi1, Richard Buxton1 1Radiology, University of California, San Diego, San Diego, CA, United States Previous studies found that attention produces robust BOLD modulation with only modest increase in firing activity in primary visual cortex. This could be due to a pure preemptive CBF increase with no relation to local neuronal firing. We tested the presence of such a mechanism using combined CBF/BOLD measurements to estimate relative CMRO2. Results show that attentional enhancement of V1 activity involves an increase of both metabolic activity and blood flow, rather than a preemptive increase in blood flow alone. The ratio of CBF to CMRO2 change appears to be higher when the stimulus is unattended than when attended. Mauro DiNuzzo1, Federico Giove1,2, Bruno Maraviglia1,2 1Physics, Sapienza University of Rome, Rome, RM, Italy; 2MARBILab, "Enrico Fermi" Center, Rome, Italy Functional magnetic resonance imaging (fMRI) is widely used to map brain function. Nevertheless, it does measure neural activity only indirectly via hemodynamic changes. Here we performed fMRI in combination with 1H-MRS in order to study the relationships between the vascular and metabolic response of the brain to a visual stimulation paradigm specifically designed to partly disentangle spiking and synaptic activity within the primary visual cortex. Our results, though preliminary, confirm that the energetics of the stimulated brain contains more information than that revealed by fMRI alone, thereby indicating an uncoupling between hemodynamics and metabolism upon brain activation. 1119. Decrease of Deoxy-Hemoglobin Containing Blood Volume in Activated Human Visual Cortex Xiang He1, Dmitriy A. Yablonskiy1 1Mallinckrodt Institute of Radiology, Washington University in St Louis, School of Medicine, St. Louis, MO, United States Quantification of brain hemodynamic parameters during functional activation is essential for understanding biophysical mechanisms behind blood oxygenation level depend (BOLD) phenomenon. Models of BOLD signal are often derived based on a relationship established by PET studies between cerebral blood volume (CBV) and cerebral blood flow (CBF), ignoring that only portion of CBV - deoxyhemoglobin-containing blood volume (DBV) affects BOLD signal. In this study, we directly measure DBV during visual activation in human visual cortex area using qBOLD-fMRI technique. We demonstrate for the first time that DBV decreases during functional activation an effect opposite to well known increase in CBV. 1120. Investigating the Origins of the DfMRI Signal Using 4 Tesla R.Allen Waggoner1, Keiji Tanaka1, Kang Cheng1,2 1Laboratory for Cognitive Brain Mapping, RIKEN-BSI, Wako-shi, Saitama, Japan; 2fMRI Support Unit, RIKEN-BSI, Wako-shi, Saitama, Japan Recent DfMRI studies preformed at 3T have observed an increase in the fractional BOLD signal change with increasing b value during functional stimulation. The origin of this effect remains controversial with both cell swelling and vascular sources being offered as explanations. If this effect is truly due to cell swelling, increasing the static magnetic field will not alter the effect. We present DfMRI results obtained at 4T which shows a constant BOLD signal change with increasing b value. This result is consistent with a vascular source for a varying DfMRI response with diffusion weighting seen at 3T. Mauro DiNuzzo1, Federico Giove1,2, Bruno Maraviglia1,2 1Physics, Sapienza University of Rome, Rome, RM, Italy; 2MARBILab, "Enrico Fermi" Center, Rome, RM, Italy Resting oscillatory patterns in cortical activity can originate by both network- and metabolism-related mechanisms. In particular, recent evidences suggest that the cell metabolic state exert an indirect control over the intrinsic network responsivity of the brain, much likely via astrocytic intracellular calcium (Ca2+)-mediated gliotransmission. Here we examined theoretically the contribution of astrocytes in the generation of the fMRI signal changes in the absence of focal neuronal stimulations. We found that oscillations in brain electrical, metabolic and vascular activity, as revealed by BOLD fMRI, can be qualitatively and quantitatively explained by calcium-mediated coupling between neuroglial activation and metabolism. Umesh Suryanarayana Rudrapatna1, Maurits P. van Meer1, Annette van der Toorn1, Rick M. Dijkhuizen1 1Image Sciences Institute, University Medical Center, Utrecht, Netherlands While existing functional MRI techniques can reliably detect stimulus-induced activation in gray matter, activity in white matter regions has not been readily measured. A recent study has reported subtle increases in fractional anisotropy (FA) in specific white matter pathways in response to motor or visual stimulation in human subjects. In the current study, we aimed to validate these findings with a direct cortical stimulation paradigm in rats. Our functional DTI approach revealed significant but variable FA changes in restricted corpus callosum regions, which demonstrates that functional DTI enables detection of white matter activity in response to cortical stimulation.
1123. Whole-Brain Mapping of Venous Vessel Size in Humans Using the Hypercapnia-Induced BOLD Effect Thies Halvor Jochimsen1,2, Dimo Ivanov2, Derek V M Ott2, Wolfgang Heinke3, Robert Turner2, Harald E. Möller2, Jürgen R. Reichenbach1 1Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital, Jena, Germany; 2Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 3Department of Anesthesiology and Intensive Care Medicine, University of Leipzig, Medical Faculty, Leipzig, Germany It is demonstrated that non-invasive mapping of the venous microstructure (vessel radius) is possible by using the hypercapnia-induced BOLD effect. Furthermore, it is shown that maps of venous blood volume and vessel density can be obtained from the same experimental setup. These parameters are important for characterizing tumor angiogenesis and type. Jeroen Cornelis Siero1, Natalia Petridou2,3, Johannes Marinus Hoogduin2, Nick F. Ramsey1 1Rudolf Magnus Institute, University Medical Center Utrecht, Utrecht, Netherlands; 2Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 3SPMMRC, University of Nottingam, Nottingam, United Kingdom A limitation of T2*w BOLD fMRI is the confounding contribution of signal from the larger vasculature. Based on time-to-peak and full-width-at-half-maximum BOLD characteristics of different vascular compartments identified at 3T, we characterized the spatio-temporal properties of the BOLD response at 7T in the visual cortex using an event-related fMRI paradigm with short visual stimuli, high sampling rate, and multiple spatial resolutions. For the smallest voxelsize a high time-to-peak spatial heterogeneity of the BOLD response was observed with fast responses localized in parenchyma. This opens the possibility to use TTP to probe layer specific BOLD responses in the human brain. 1125. Linearity of Neural Responses in the Somatosensory Cortex and Their Relationship to BOLD FMRI. Fan Wang1, Claire Stevenson1, Matthew Brookes1, Peter Morris1 1Physics, Sir Peter Mansfield Magnetic Resonance Centre, Nottingham, Nottinghamshire, United Kingdom We use the combination of MEG and fMRI to study the neural basis for BOLD non-linearity. Both nonlinear neural responses to stimuli and nonlinear vascular responses to neural activity may contribute to BOLD non-linearity and the relative contribution of these two effects remains poorly understood. We extended the study of non-linear neural response to both phase locked evoked response and time related beta oscillations in somatosensory cortex. The N20 peak amplitudes show non-linearities with ISI of 0.25-2s, influenced by beta power at the time of stimulation, suggesting that best oscillation should also be considered for BOLD convolution. 1126. Simultaneous BOLD and NIRS Signal Correlation During Hypoxia Matthew Borzage1,2, Marvin Nelson3, Istvan Seri1,4, Stefan Blüml3,5 1Neonatal Medicine, Childrens Hospital Los Angeles, Los Angeles, CA, United States; 2Viterbi School of Engineering, University of Southern California, Los Angeles, 90007, United States; 3Department of Radiology, Childrens Hospital Los Angeles, Los Angeles, CA, United States; 4Keck School of Medicine, University of Southern California, Los Angeles, CA, United States; 5Rudi Schulte Research Institute, Santa Barbara, CA, United States Studying changes in cerebral hemodynamics is possible via MR, including blood oxygen level dependent (BOLD) imaging. We used near infrared spectroscopy (NIRS) to sample oxy- and deoxyhemoglobin directly, and utilized a nitrogen challenge to change FiO2 and thus cause measurable changes in blood oxygenation. We have observed good correlation between the BOLD and NIRS signals, with higher correlation in the gray matter than in the white matter. In the near future, we will use this paradigm to study the limited autoregulation of cerebral blood flow in preterm neonates. Jun Hua1, Robert Stevens1, Manus J. Donahue1,2, Alan J. Huang1, James J. Pekar1, Peter C.M. van Zijl1 1Department of Radiology, The Johns Hopkins University, Baltimore, MD, United States; 2Department of Clinical Neurology, Oxford University, Oxford, United Kingdom Changes in CBF/CBV/arterial-CBV(CBVa)/post-arterial-CBV(CBVpa) were measured in human brain during breath-hold and visual stimulation. δCBV/CBV was larger during breath-hold (54.9+/-5.8%) than visual stimulation (28.2+/-5.2%), a difference primarily originating from δCBVpa/CBVpa (54.5+/-4.9% vs. 22.2+/-3.8%); δCBVa/CBVa (53+/-6%) and δCBF/CBF (61+/-7%) were comparable in both tasks. During breath-hold, vasodilation distributed proportionally among arterial and post-arterial compartments, whereas, during visual stimulation, relative change in CBVa was greater than that in CBVpa. Our data indicate that the coupling between arterial-CBV and CBF was largely preserved during both tasks (rCBVa=rCBF0.86+/-0.05), while the relationship between total-CBV and CBF was substantially different between breath-hold (rCBV=rCBF0.90+/-0.05) and visual (rCBV=rCBF0.52+/-0.04) stimulation. Daniel Pflugfelder1, Kaveh Vahedipour1, Kamil Uludag2, Nadim Jon Shah1,3, Tony Stöcker1 1Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Forschungszentrum Jülich GmbH, Jülich, Germany; 2Max-Planck Institute for Biological Cybernetics, Tuebingen, Germany; 3Faculty of Medicine, Department of Neurology, RWTH Aachen University, Aachen, Germany To increase the spatial specificity of the BOLD signal, a large ratio R of microvascular to macrovascular BOLD signal is desirable. This can be be achieved using spin echo sequences. To simplify the calculation the extravascular BOLD signal (EV) is often approximated by a mono-exponential decay (MEA). To investigate the effect of the MEA we calculated R for multiple B0 and TE without using this approximation. The parameter range for an optimal R was considerable different to the results obtained using the MEA. This is mainly due to an vessel radius dependent delay of the EV which is not reproduced by the MEA. 1129. A Realistic Vascular Model for BOLD Signal Up to 16.4 T. Bernd Michael Müller-Bierl1, Verena Pawlak2, Jason Kerr2, Kamil Ugurbil3, Kamil Uludag1 1MRC, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany; 2NWG, Max-Planck Institute for Biological Cybernetics, Tübingen, Germany; 3Center for Magnetic Resonance Research, University of Minnesota, Minnesota, Minneapolis, United States We present a realistic vascular model based on Monte-Carlo modeling of diffusion and the finite element method to compute the background magnetic field of partly oxygenated finite venules exposed to up to 16.4 T. Our data show that the realistic vasculature data set is necessary to account for the effects due to finite-sized vessels. The venule data herein stems from 2 photon microscopy of the rat brain. Results show that the infinite vessel model is prone to error so that the use of realistic vascular data sets is necessary to get precise results. However, for a better understanding more realistic vascular data sets should be examined in future work.
1130. Relaxation of Blood at High Field: Another Exchange Regime Ksenija Grgac1,2, Qin Qin1,3, Michael McMahon1,3, Jason Zhao1, Peter C.M. van Zijl1,3 1Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States; 2Department of Chemistry, Johns Hopkins University, Baltimore, MD, United States; 3F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States To study the intravascular BOLD mechanism, we used a physiologically controlled blood perfusion system at 9.4T under oxygenated conditions for a series of hematocrits. Previous studies have shown that, at such high fields, the two-site (eryhtrocyte-plasma) fast exchange model can not describe oxygenation-based relaxation changes properly in that it gives incorrect lifetimes for water in erythrocytes (1-3ms). We show that, for the physiological range of hematocrits, a general two-site exchange model (including slow, fast and intermediate regimes) can appropriately describe blood relaxation in oxygenated blood and provides an erythrocyte lifetime of 12.2±3.7ms, in agreement with literature values 1131. Blood Longitudinal (T1) and Transverse (T2) Relaxation Times at 11.7 Tesla Ai-Ling Lin1, Xia Zhao1, Peter T. Fox1, Timothy Q. Duong1 1Research Imaging Institute, University of Texas Health Science Center, San Antonio, TX, United States Knowledge of blood T1 and T2 values are important for many MRI studies that include BOLD modeling, high spatial specificity BOLD fMRI, blood flow MRI using arterial spin labeling (ASL), and blood volume MRI using vascular space occupancy (VASO) techniques. The purpose of the present study was to determine blood T1 and T2 values at 11.7T as a function of oxygenation level (Y), temperature, hematocrit fraction (Hct) and field strength (B0). Xiaopeng Zong1, Jie Huang1,2 1Department of Radiology, Michigan State University, East Lansing, MI, United States; 2Neuroscience Program, Michigan State University, East Lansing, MI, United States A quantitative ER-fMRI study requires to measuring hemodynamic response function (HRF) both accurately and precisely. A periodic ER-fMRI design can produce a high accuracy of HRF measurement but a low precision. Utilizing the approximate linearity of the HRF, a rapid-presentation (RP) ER-fMRI design can improve the precision by shorting intersitimulus interval (ISI). Nevertheless, hemodynamic response is non-linear and its corresponding effect on the estimated HRF increases with decreasing ISI, rendering the estimated HRF inaccurate for small ISI values. Accordingly, as demonstrated in this preliminary study, an optimal RP ER-fMRI design should maximize both accuracy and precision of HRF measurements. fMRI: Respiratory Calibrations Hall B Wednesday 13:30-15:30 1133. Saturation of Visually Evoked BOLD Response During Carbogen Inhalation Claudine J. Gauthier1,2, Cécile Madjar2, Richard D. Hoge1,2 1Physiology/Biomedical Engineering, Université de Montréal, Montréal, Quebec, Canada; 2CRIUGM, Montreal, Quebec, Canada Oxidative metabolism can be estimated from the BOLD signal following a calibration manipulation to determine a factor M. M is the maximum possible BOLD signal change. Carbogen inhalation was used here with intense visual stimulation to test whether an asymptote in BOLD signal could be reached. Results show a convergence of percent BOLD changes around 9% in visual cortex for 10% carbogen alone, and 5-10% carbogen breathing plus visual stimulation. The diminishing incremental response from visual stimulation at high carbogen concentrations suggests that these manipulations approach BOLD levels close to the saturation plateau. 1134. Calibrated FMRI During a Cognitive Stroop Task in the Aging Brain Rafat Saeed Mohtasib1,2, Vanessa Sluming1,2, Laura Parkes1,3 1Magnetic Resonance and Image Analysis Research Centre (MARIARC), The University of Liverpool, Liverpool, United Kingdom; 2Medical Imaging Department, The University of Liverpool, United Kingdom; 3Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, The University of Manchester, United Kingdom Calibrated fMRI is a new technique that allows quantitative estimates of the relative changes in cerebral metabolic rate of oxygen (ÄCMRO2) and cerebral blood flow (ÄCBF) that accompany neural activation. In this research we extend our previous work to study changes in neurovascular coupling over an age range during a cognitive Stroop task. 37 volunteers (age range 20-70) were scanned using 3T MRI. We found BOLD response to the Stroop task increases with increasing age, calibration constant A was found to reduce with age, a trend to reduced ÄCMRO2 with increasing age, and globally ÄCBF did not change with age.
1135. Error Propagation in CMRO2 Derivations Using CBF and BOLD Imaging Hsiao-Wen Chung1, Wen Chau Wu 1Electrical Engineering, National Taiwan University, Taipei, Taiwan, Taiwan The purpose of this study is therefore to investigate the issues error propagation in CMRO2 estimations under different CNR. Results from our error propagation study suggest that CMRO2 estimations using CBF and BOLD are valid only when the CNR for CBF measurements is sufficiently large, or when the underlying changes in CMRO2 and CBF are sufficiently large as in hypercapnic experiments. Validity of current instantaneous CMRO2 measurements for resting-state brain functional studies is therefore in some doubt. 1136. Effects of the ValSalva Maneuver and Hypercapnia on the BOLD Signal Daniel A. Handwerker1, Paula Wu1,2, Ronald M. Harper3, Peter A. Bandettini1,4 1Section on Functional Imaging Methods, National Institute of Mental Health, Bethesda, MD, United States; 2Neuroscience, University of California, Los Angeles, Los Angeles, CA, United States; 3Neurobiology, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States; 4Functional MRI Facility, National Institute of Mental Health, Bethesda, MD, United States Hypercapnia creates global changes in cerebral blood flow, volume, and oxygenation that can be measured with fMRI and used for calibration. Breath-holding is a simple way to induce hypercapnia, but it may alter thoracic chest pressure and include a ValSalva effect. We alter chest pressure while keeping the hold duration constant to see how the BOLD signal changes. The initial BOLD undershoot and following peak scale with pressure. Because the precise contrast mechanisms behind these changes are not fully understood, they may be a confound in calibration studies, or a novel way to rapidly induce calibration-useful global BOLD signal changes. 1137. Hypoxia and Hyperoxia Alter Brain Metabolism in Awake Human Feng Xu1, Uma Yezhuvath1, Peiying Wang1, Hanzhang Lu1 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States Many studies tried to understand how neural activity change vascular parameters, but little attention was received to whether gas content changes in blood would reversely alter neural activity. To investigate such an effect, we used a recently developed MRI technique to quantify global cerebral metabolic rate of oxygen (CMRO2) under hypoxia and hyperoxia. Our data suggest that a change in arterial oxygen content can modulate brain metabolism in a dose-dependent manner, with hypoxia increasing CMRO2 and hyperoxia decreasing it. Therefore, in addition to the well-known forward neurovascular coupling, the reverse coupling may be important in the regulation of brain function. Clarisse Ildiko Mark1, M. Slessarev2, S. Ito3, J. Han2, J. A. Fisher2, G. B. Pike1 1McConnell Brain Imaging Center, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada; 2Department of Anaesthesiology, University Health Network, Univeristy of Toronto,, Toronto, Ontario, Canada; 3Department of Anaesthesiology and Medical Crisis Management, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan Manual HC calibration depends on intrinsically low signal-to-noise perfusion imaging and individual vascular architecture, with resulting calibration (M)-values prone to large intra- and inter-subject variations that may bias oxygen metabolism studies. We thereby sough to investigate HO as a calibration alternative under rigorous control of end-tidal partial pressures of CO2 (PetCO2) and O2 (PetO2). Our findings suggest the viability of precisely controlling HO stimulation to provide more precise per-subject and per-brain-region M-estimates, based on high SNR PaO2 measurements and the removal of the confound of vascular variation in population observed under HC-calibration. fMRI Analysis Methods Hall B Thursday 13:30-15:30 Dave Langers1,2 1Otorhinolaryngology, University Medical Center Groningen, Groningen, Netherlands; 2Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States Spatial Independent Component Analysis (sICA) is increasingly being used for the analysis of fMRI datasets with unpredictable response dynamics, like in resting state experiments. However, group-level statistical assessments are difficult, and proper statistical characterization and validation under the null-hypothesis are so far lacking. In the current study, a novel method is proposed that is based on retrospective matching of individual component maps to aggregate group maps. Selection bias is analytically predicted and explicitly corrected for. It is shown that valid outcomes are obtained, in the sense that the achieved specificity does not violate the imposed confidence levels, only if bias-correction is applied. Sensitivity and discriminatory power remain acceptable, and only moderately smaller than those of a biased method. Finally, it is shown that the method is able to identify significant effects of interest in an actual dataset, proving its applicability as a group-level sICA fMRI data analysis method. 1140. Eigenvector Centrality Mapping as a New Model-Free Method for Analyzing FMRI Data Gabriele Lohmann1, Daniel S. Margulies1, Dirk Goldhahn1, Annette Horstmann1, Burkhard Pleger1, Joeran Lepsien1, Arno Villringer1, Robert Turner1 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany We introduce a new assumption- and parameter-free method for the analysis of fMRI resting state data based on eigenvector centrality. Eigenvector centrality attributes a value to each voxel in the brain such that a voxel receives a large value if it is strongly correlated with many other nodes that are themselves central within the network. Google's PageRank algorithm is a variant of eigenvector centrality. We tested eigenvector centrality mapping (ECM) on two resting state scans of 35 subjects, and found a network of hubs including precuneus, thalamus and sensorimotor areas of the marginal ramus of the cingulate and mid-cingulate cortex.
1141. ROI Atlas Generated from Whole Brain Parcellation of Resting State FMRI Data Richard Cameron Craddock1,2, George Andrew James3, Paul Edgar Holtzheimer2, Xiaoping P. Hu3, Helen S. Mayberg2 1Electrical and Computer Engineering, Georiga Institute of Technology, Atlanta, GA, United States; 2Psychiatry, Emory University, Atlanta, GA, United States; 3Biomedical Imaging Technology Center, Emory University/Georgia Institute of Technology, Atlanta, GA, United States Network analysis of resting state fMRI data requires the specification of ROIs. This is a difficult process fraught with error. We propose a method for developing an ROI atlas by whole brain parcellation of resting state data in functinally homogenous, contiguous regions. 1142. fMRI Topographic Mapping of the Somatosensory Cortex at 7T Using Multigrid Priors Selene da Rocha Amaral1, Sue Francis1, Penny Gowland1, Nestor Caticha2 1Sir Peter Mansfield Magnetic Centre, University of Nottingham, Nottingham, Notts, United Kingdom; 2Institute of Physics, University of Sao Paulo, Sao Paulo, Brazil We have applied a Bayesian non-parametric multiscale technique, the iterated Multigrid Priors method, to map the digits of the hand in primary somatosensory cortex for 1mm isotropic spatial resolution data. It is data driven and makes no assumption about the local hemodynamic response as a function of time or space. It was able to detect an orderly pattern of response phases on the posterior bank of the central sulcus (postcentral gyrus) suggesting that the method can also be extended for retinotopic mapping studies of visual cortex. We also showed variations in HRs across digits through local posterior spatial averages. 1143. Support Vector Regression Prediction of Graded FMRI Activity Yash Shailesh Shah1, Douglas C. Noll, Scott J. Peltier 1Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States Support Vector Regression is a machine learning technique that learns the mapping from the training set and labels provided. This creates a model which can then be used to give predictions for all testing sets. The prediction is really quick and hence SVR has potential to be used as a tool for real-time biofeedback applications to evaluate graded potential. In this study, we have used SVR analysis to evaluate graded activation in multiple neural systems namely the visual and motor cortex activation. The outputs are encouraging and advocate prospects of using SVR for future work in building real-time biofeedback applications in which graded activation needs to be evaluated. 1144. A Comparison of SVM and RVM for Real-Time FMRI Applications Daniel Antonio Perez1, Richard Cameron Craddock2, George Andrew James1, Xiaoping Philip Hu1 1The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, Atlanta, GA, United States; 2School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta,, GA, United States Support vector machines (SVM) and relevance vector machines (RVM) are two machine learning algorithms which have gained popularity due to its sensitivity to networks of brain activation. Despite their recent extensive use in fMRI research, little contribution has been put forth to compare these different algorithms. Both models were compared for speed and prediction accuracy. The results revealed that both RVM and SVM are comparable in classification accuracy. However, RVM is capable of performing the task much faster and with a sparser model. Feature selection was also found to increase both speed and classification accuracy for both SVM and RVM. Gabriele Lohmann1, Wolfgang Heinke2, Burkhard Pleger1, Joeran Lepsien1, Stefan Zysset3, Robert Turner1 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2Dept. of Anesthesiology and Intensive Medicine, University of Leipzig, Leipzig, Germany; 3NordicNeuroLab, Norway Propofol is an anesthestic agent widely used in clinical practice which is known to affect episodic memory. The exact mechanism causing this effect is still unclear. Here we investigated whether propofol has a region-specific effect on functional connectivity in fMRI data. Subjects were scanned under the influence of propofol or a placebo. Functional connectivity was assessed using an algorithm new to fMRI data analysis called 'eigenvector centrality'. Our results suggest that the well known impairment of episodic memory after propofol infusion is related to an impaired function of cerebellar regions known to be involved in memory encoding.
1146. The Rényi Entropy in Data-Driven Analysis for Pharmacological MRI John McGonigle1, Andrea L. Malizia2, Robin Holmes3, Majid Mirmehdi1 1Computer Science, University of Bristol, Bristol, United Kingdom; 2Psychopharmacology Unit, University of Bristol, Bristol, United Kingdom; 3Medical Physics, United Bristol Healthcare NHS Trust, Bristol, United Kingdom Data-driven analysis is useful in pharmacological MRI where there may be no model of neural response available a priori. It is recognised that the signal complexity of noise will usually be higher than any signal of interest. Renyi entropy may be used to discover the complexity of a time frequency representation of a voxel time course. Its application here at every voxel in a region of interest across several subjects shows it is capable of discovering drug effect which is not found when the same analysis is carried out on placebo data. 1147. Functional MRI Constrained EEG Sources Localization for Brain State Classification Changming Wang1,2, Zhihao Li1, Gopikrinsha Desphande1, Li Yao2, Xiaoping Hu1 1Biomedical Engineering, Emory Univ./Georgia Tech., Atlanta, GA, United States; 2Inst. of Cog. Neurosci. & Learning, Beijing Normal Univ., Beijing, China We used fMRI to assist single-trial EEG signal classification by transforming scalp EEG into corresponding source activation patterns. The classification performance for 4 categories visual perception task was around 98%. 1148. Development of an Automated Threshold Technique Based on Reproducibility of FMRI Activation. Tynan Stevens1,2, Steven Beyea, 12, Ryan D'Arcy2,3, David Clarke4,5, Chris Bowen, 12, Gerhard Stroink1 1Physics, Dalhousie University, Halifax, NS, Canada; 2NRC Institute for Biodiagnostics (Atlantic), Halifax, NS, Canada; 3Neuroscience, Dalhousie University, Halifax, NS, Canada; 4Neurosurgery, QEII Health Science Center, Halifax, NS, Canada; 5Surgery, Dalhousie University, Halifax, NS, Canada Setting activation thresholds remains a challenge in functional MRI. While strategies exist to address the increased chance of false positive activations due to the large number of voxels in an fMRI image, these methods frequently ignore differences in activation strength between tasks, individuals, and scanners. Setting appropriate thresholds is particularly pertinent in presurgical mapping, as knowledge of the location and extent of functional cortex can affect surgical decisions. In this work, we demonstrate an automated threshold technique based on test-retest imaging and receiver-operator characteristic curves, which produces individualized threshold levels optimized for reproducibility of the observed activation. Cesar Caballero-Gaudes1, Natalia Petridou, 12, Susan Francis1, Penny Gowland1 1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2University Medical Centre Utrecht, Utrecht, Netherlands In recent work we showed that by means of sparse estimation techniques the spatial and temporal evolution of single-trial BOLD responses can be automatically detected without any prior knowledge of the stimulus timing and without thresholding: paradigm free mapping (PFM). However, fMRI time series also contain physiological and instrumental fluctuations which can hinder the detection of BOLD responses associated to neuronal activity. Physiological fluctuations can be removed prior to PFM via high-pass filtering, or by RETROICOR, RVT or RVHRCOR, but these techniques must be employed in a pre-processing stage and require the additional recording of physiological respiratory and cardiac waveforms. Here, extending on our previous work, we present a novel technique which by decomposing the fMRI signal enables automatic detection of fMRI BOLD responses without prior stimulus information and automatic fitting of significant frequency fluctuations present in the signal, such as non-neuronal cardiac and respiratory fluctuations (semiparametric PFM, sPFM). This technique is based on a semiparametric linear representation of the fMRI signal which is recursively fitted using a morphological component analysis algorithm. The feasibility of this technique was evaluated in simulations and real fMRI data acquired at 7T, and its performance validated to RETROICOR. Andrew Fischer1, Jonathan Lisinski2, Pearl Chiu2, Brooks King-Casas2, Stephen LaConte2 1Rice University, Houston, TX, United States; 2Neuroscience, Baylor College of Medicine, Houston, TX, United States A pattern-based rt-fMRI system capable of multi-session and group-based models enables progressive training and testing across sessions, and potentially enables the use of group models for rehabilitation/therapy using multi-voxel targets built from databases of recovered individuals. Here we investigate alignment strategies to verify that there is not a significant tradeoff between classification accuracy and rt-fMRI computational demands. Our results demonstrate the feasibility of a model-to-scan alignment system for real-time fMRI in which the least demanding computational approach does not lead to a compromise of classification accuracy. This work also demonstrates the feasibility of using group SVM models in real-time experiments. 1151. Constrained CCA with Different Novel Linear Constraints and a Nonlinear Constraint in FMRI Dietmar Cordes1, Rajesh Nandy2, Mingwu Jin1 1Radiology, University of Colorado Denver, Aurora, CO, United States; 2Biostatistics and Psychology, UCLA, Los Angeles, CA, United States Multivariate statistical analysis has recently become popular in fMRI data analysis as such methods can capture better the spatial dependencies between neighboring voxels. One such method is local canonical correlation analysis (CCA) where one looks at the joint time courses of a group of neighboring voxels. It is known that CCA without any constraints can lead to significant artifacts and an increase in false activations. Here, we investigate different novel linear constraints and a nonlinear constraint for CCA and propose a method that rectifies the weakness of conventional CCA mentioned above.
1152. An Optimized Clustering Technique for Functional Parcellation of Hippocampus Arabinda Mishra1, James C. Gatenby1, Allen T. Newton1, John C. Gore1, Baxter P. Rogers1 1Radiology & Radiological Science, VUIIS, Nashville, TN, United States Functional sub-divisions of important anatomic regions in the human brain are normally done based on disparities in structural connectivity patterns or functional connectivity maps. However, quantification of functional heterogeneity, and determining the appropriate number of sub-regions, has rarely been a focus of study. This work evaluates the use of self organized maps (SOM) to classify the functionally different regions in the hippocampus, which exhibits functional and sometimes anatomical differences in patients with disorders such as schizophrenia and bipolar disorder etc. Using voxel based connectivity maps we successfully parcellated left hippocampus and found performance of SOM to be superior in comparison to kmeans clustering. 1153. Spatiotemporal Dynamics of Low Frequency Fluctuations in BOLD FMRI of Rats and Humans Waqas Majeed1, Matthew Magnuson1, Shella Keilholz1 1Biomedical Engineering, Georgia Institute of Technology / Emory University, Atlanta, GA, United States Presence of propagating spatiotemporal waves in low frequency fluctuations (LFFs) has recently reported using high temporal resolution single slice BOLD fMRI of the rat brain. We have developed a novel method for automatic detection of such patterns and some initial findings for multslice rat and human data are presented in this abstract. Andrew Scott Nencka1, Daniel L. Shefchik1, James S. Hyde1, Andrzej Jesmanowicz1, Daniel B. Rowe2 1Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 2Department of Mathematics, Statistics and Computer Science, Marquette University, Milwaukee, WI, United States The T2* contrast mechanism associated with the BOLD signal is well known, as is its echo time (TE) dependence. In this abstract, we present a method for analyzing data acquired with interleaved echo times. Based upon the expected BOLD TE behavior, the ratio of the regression coefficients for the task related columns of the design matrix may be used to identify voxels which exhibit BOLD-like responses. Shr-Tai Liou1, Hsiao-Wen Chung1, Wei-Tang Chang2, Fa-Hsuan Lin2,3 1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; 2Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; 3A. A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, United States We propose the eigenspace L1-norm beamformer, a new novel technique for ultrafast MR inverse imaging (InI) reconstruction. This method minimizes the amplitude of the beamformer output quantified by the L1-norm of the spatial filter coefficients. We tested this method to reconstruct functional MR InI measurements using a visuomotor task. Results show that the eigenspace L1-norm beamformer can detect BOLD contrast functional activity and provide higher spatial resolution than linear constrained minimum variance (LCMV) beamformer in both motor and visual cortices. 1156. Filtering FMRI Using a SOCK Kaushik Bhaganagarapu1,2, Graeme D. Jackson1,3, David F. Abbott1,2 1Brain Research Institute, Florey Neuroscience Institutes (Austin), Melbourne, Victoria, Australia; 2Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia; 3Departments of Medicine and Radiology, The University of Melbourne, Melbourne, Victoria, Australia BOLD fMRI is restricted by low signal to noise and various artifacts varying from motion to physiological noise. Independent components analysis (ICA) is a data-driven analysis approach that is being used to filter fMRI of such noise. However, one of the problems with ICA remains the interpretation of the results. Recently, we developed an automatic classifier (Spatially Organised Component Klassifikator - SOCK), which uses spatial criteria to help distinguish plausible biological phenomena from noise. We utilize SOCK to automatically filter a conventional fMRI block-design language study and successfully show the significance of activation obtained increases as a result of SOCK. 1157. Real Time FRMI: Machine Learning or ROIs? Thomas WJ Ash1, T Adrian Carpenter1, Guy B. Williams1 1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom The first applications of real time fMRI used voxel intensity averaging over a ROI to provide feedback, whereas recent work has shown that machine learning tools may improve performance. We conduct a comparison between the two techniques, and find that support vector machines (SVM) outperform averaging over a ROI no matter how restricted an ROI we use. Further to this, we find that SVM performance does not decrease as sharply as ROI averaging when block length is decreased. 1158. Using Dynamically Adaptive Imaging with FMRI to Rapidly Characterize Neural Representations Rhodri Cusack1, Michele Veldsman1, Lorina Naci2, Daniel Mitchell1 1MRC CBU, Cambridge, Cambs, United Kingdom; 2University of Cambridge, Cambridge, United Kingdom Dynamically Adaptive Imaging (DAI) is a new real-time paradigm for fMRI. BOLD data were analyzed using our open-source real-time software and used to iteratively and automatically adapt the stimuli presented to the volunteer. DAI was applied to investigate feature coding in ventral visual cortex. Pictures of objects were presented on a screen. We performed an iterative search, in which the outcome of the experiment was the neural neighborhood of stimuli that evoked the most similar pattern of neural response to a referent stimulus. DAI converged rapidly and found object-specific tuning to complex conjunctions of sensory and semantic features.
Jaimie B. Dougherty1, Christopher J. Conklin2, Karen Moxon1, Scott Faro2, Feroze Mohamed2 1Drexel Univesrity, Philadelphia, Pa, United States; 2Temple University, Philadelphia, Pa Combined EMG and fMRI is very desirable. Detecting changes in muscle activity associated with changes in cortical activity can greatly improve our understanding of neuroplastic changes and the affects of treatments in neuromuscular conditions. This work proposes a robust wavelet-based artifact reduction strategy that allows for the distinction between two muscular conditions in an MR environment. This work also introduces the use of the EMG parameter median frequency as a covariate in a motor fatigue study to better refine image analysis. Ali Mohammad Golestani1, Bradley G. Goodyear2,3 1Electrical & Computer Engineering, University of Calgary, Calgary, AB, Canada; 2Radiology & Clinical Neuroscience, University of Calgary, Calgary, AB, Canada; 3Seaman Family MR Research Centre, Calgary, AB, Canada Resting-state fMRI analysis techniques that determine the similarity between time varying signals of seed and target regions assume the signals are stationary; however, the resting-state varies between subjects and is susceptible to unwanted brain activity due to inadvertent movements or cognition. In this study, we introduce a time-frequency approach based on the Stockwell transform to temporally resolve coherence between resting-state signals. We demonstrate S-Coherence can reduce the contribution of unwanted hand movements in the determination of the resting-state connectivity within the motor network, and hence reduce within-subject variability in comparison with existing techniques (temporal cross-correlation and coherence). 1161. A Novel Data Processing Method for Olfactory FMRI Examinations Xiaoyu Sun1, Jianli Wang1, Christopher W. Weitekamp1, Qing X. Yang1,2 1Radiology, Penn State University College of Medcine, Hershey, PA, United States; 2Neurosurgery, Penn State University College of Medicine, Hershey, PA, United States Here we present an olfactory fMRI data processing method that can significantly improve the data processing quality when the patients respiration pattern is not controlled and doesnt synchronize with olfactory stimulation paradigm. As an example of implementation we present an olfactory fMRI examination while the subjects respiration pattern is not regular. Our data demonstrates that it is critical to consider the subjects respiratory patterns modulation on the olfactory stimulation paradigm. The presented olfactory fMRI data processing method can be used for various applications. In addition to the example of real time respiration data, subjective response data (not provided here) can also be convolved with odor delivery data for more improved fMRI data processing. This experimental set-up will be useful in the olfactory fMRI study of neuropsychiatric and neurologic patients that are not cooperative or be able to follow the breathing instructions. 1162. Physiological Noise Extraction in FMRI Data Using Empirical Mode Decomposition Hsu-Lei Lee1, JĆ¼rgen Hennig1 1Department of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany Physiological noise caused by ecg- and/or breathing related pulsatility may introduce temporal correlations that are unrelated to neuronal processes in a resting-state network analysis. As physiological noise is often non-linear and non-stationary, signal extracted by simple filtering will deviate from the actual noise, and so as global regression methods like RETROICOR. In this study we implemented empirical mode decomposition (EMD) on resting-state fMRI time-series and extracted cardiac components which has a time-frequency curve that well matches the true heart rate acquired by external ECG during the scan. 1163. Characterization and Correction of Physiological Instabilities in 3D FMRI Rob Hendrikus Tijssen1, Steve M. Smith1, Peter Jezzard1, Robert Frost1, Mark Jenkinson1, Karla Loreen Miller1 1FMRIB Centre, Oxford University, Oxford, Oxon, United Kingdom 3D FMRI acquisitions have the advantage of allowing high resolution, isotropic, imaging. However, 3D acquisitions, such as SSFP and SPGR, show increased signal instabilities in the inferior regions of the brain. Here, we present a characterization of these temporal instabilities and propose a GRAPPA-based correction method that allows retrospective gating of 3D FMRI data. 1164. Length-Scale Dependent Effects of Noise Reduction in Phase and Magnitude FMRI Time-Series Gisela E. Hagberg1, Marta Bianciardi2, Valentina Brainovich1, Antonino Maria Cassara3,4, Bruno Maraviglia3,4 1Santa Lucia Scientific Foundation, Rome, Italy; 2Advanced MRI Section, LFMI, NINDS, National Institutes of Health, Bethesda, MD, United States; 3Dept. Physics, Sapienza University, Rome, Italy; 4Centro Studi e Ricerche "Enrico Fermi" fMRI analyses are primarily based on the magnitude information in gradient-echo echo-planar images (GE-EPI) but a growing number of studies also included the phase information. An issue relates to physiologic large-scale phase effects that are more prominent in phase than magnitude data. In the present work we explored the phase stability at different length scales at 3T and found that improvements in temporal stability could be achieved by alternative noise-reduction methods that take into account the differential origin of noise effects in phase and magnitude data. 1165. Comparison of Feature Selection Methods for Classification of Temporal FMRI Volumes Using SVM Ayse Ece Ercan1, Esin Karahan2, Onur Ozyurt2, Cengizhan Ozturk2 1Biomedical Engineering, TU Delft, Delft, Netherlands; 2Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey High dimensional feature space of fMRI volumes has been a drawback for classification studies since large feature dimension is known to increase the classification error and the computation time. In this study, we combined PCA with two anatomical feature selection methods: grey matter (GM) and region of interest (ROI) masking, and investigated the effects of different feature reduction methods on the classification accuracy of a linear SVM classifier. To apply PCA after anatomical masking is concluded to be a reliable method for preserving the classification accuracy of the anatomical feature selection methods and reducing the computation time. Pooja Gaur1, Helen Egger1, Nan-kuei Chen2 1Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, United States; 2Brain Imaging and Analysis Center, Duke University, Durham, NC, United States EPI based fMRI has several major limitations: distortion, low spatial-resolution, and low anatomic resolvability. Therefore, it is not easy to register fMRI data to structural images, and to normalize fMRI data. EPI distortion correction and nonlinear normalization methods have been developed to address these limitations. However, it is not easy to assess how these methods perform on fMRI data with distortions, limited resolution, and anatomic resolvability. Here we report an imaging protocol based on high-resolution inversion-recovery prepared segmented EPI (with identical distortion patterns as in single-shot EPI), enabling accurate assessment of the performance for distortion correction and nonlinear normalization algorithm. fMRI Fluctuations & Connectivity Hall B Monday 14:00-16:00 Jaymin Upadhyay1,2, Julie Anderson1,2, Adam J. Schwarz1,3, Richard Baumgartner1,4, Alexandre Coimbra1,5, Lauren Nutile1,2, James Bishop1,2, Ed George1,6, Brigitte Robertson1,7, Smriti Iyengar1,3, David Bleakman1,3, Richard Hargreaves1,5, Lino Becerra1,2, David Borsook1,2 1Imaging Consortium for Drug Development, Harvard Medical School, Belmont, MA, United States; 2P.A.I.N. Group; Brain Imaging Center, McLean Hospital, Belmont, MA, United States; 3Lilly Research Department, Eli Lilly and Company, Indianapolis, IN, United States; 4Biometrics Research Department, Merck Research Laboratories, Rahway, NJ, United States; 5Imaging Department, Merck Research Laboratories, West Point, PA, United States; 6Department of Anesthesiology and Critical Care, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States; 7Sepracor, Inc., Marlborough, MA, United States Buprenorphine is commonly prescribed to treat pain. We implemented blood oxygenated-level dependent (BOLD) functional MRI to characterize and compare the effects of 2.0 mg (sublingual), 0.1 mg/70kg (intravenous) and 0.2 mg/70kg (intravenous) doses of buprenorphine on the central nervous system during pain processing and during the resting state. During pain processing, the 2.0 mg (sublingual) and 0.2 mg/70kg (intravenous) doses significantly (p<0.01) potentiated the BOLD response in regions such as the striatum, while attenuated the BOLD response in somatosensory cortices. Furthermore, the resting-state connectivity for sublingual and intravenous doses of buprenorphine were also altered among structures that mediate pain processing. Jonathan Rizzo Polimeni1, Douglas N. Greve1, Bruce Fischl1,2, Lawrence L. Wald1,3 1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, United States; 2Computer Science and AI Lab (CSAIL), Massachusetts Institute of Technology, Cambridge, MA, United States; 3Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States While voxels as small as 0.75 mm isotropic provide sufficient SNR for high-field fMRI, voxels falling within cortical gray matter voxels are still influenced by partial-volume contamination with white matter and CSF, which contribute different levels of physiological noise. Here we characterize the impact of partial-volume effects as a function of cortical depth on the resting-state fluctuation amplitudes at 7T. Even after partial-volume effects are taken into account, the magnitude of resting state fluctuations increases with proximity to the pial surface. This suggests that laminar differences in the resting-state fluctuations exist and may reflect increasing dominance of extravascular BOLD signal changes surrounding large pial vessels. 1169. Functional Connectivity During Memory Consolidation: A Resting-State FMRI Study Chia-Wei Li1, Ke-Hsin Chen2, Tai-Li Chou2,3, Keng-Chen Liang2,3, Ya-Chih Yu1, Chang-Wei Wu1, Jy-Horng Chen1,3 1Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, Taiwan; 2Department of Psychology, National Taiwan University, Taipei, Taiwan; 3Center for Neurobiology and Cognitive Science, National Taiwan University, Taipei, Taiwan Memory consolidation is a process which stabilizes a short-term memory into a long-term memory. Consolidation occurs after the initial learning lasting for a period of time. In this study, we employed resting-state experiment design to reveal the functional connectivity among hippocampus, PCC, and MTG during consolidation of memorizing easy and difficult words that would result in good and poor memory respectively. As seeds set at three ROIs, we detected increase connection with cuneus in the hard condition, implying the engagement of visual analysis; increment in connection with cerebellum and frontal cortex in the easy condition, reflecting the on-going consolidated activity. 1170. Assessing Functional Connectivity Measures at 3T and 7T Joanne Rachel Hale1, Matthew Jon Brookes1, Emma Louise Hall1, Susan T. Francis1, Peter Gordon Morris1 1SPMMRC, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom Functional connectivity, implied by inter-region correlation, has been reported in resting state BOLD activity. It is well known that as magnetic field strength is increased, BOLD contrast to noise is improved, implying that a move to high field would benefit functional connectivity measurement. However, fMRI signals are affected by non-neuronal artifacts which increase with field strength making the advantage of 7T questionable. Here, we assess non-neuronal physiological artifacts in 3T and 7T resting state data. Results show that sensorimotor cortex connectivity can be measured accurately and at high spatial resolution at 7T with little contribution from non-neuronal physiological artifact. 1171. Prediction of Functional Connectivity from Structural Brain Connectivity Fani Deligianni1, Emma C. Robinson1, Christian F. Beckmann1, David Sharp1, A. David Edwards1, Daniel Rueckert1 1Imperial College London, London, United Kingdom Studies that examine the relationship of functional and structural connectivity are important in interpreting neurophysiological data. Although, a linear relationship between functional and structural connectivity has been demonstrated, there is no explicit attempt to quantitatively measure how well functional data can be predicted from structural data. Here, we predict functional connectivity from structural connectivity by utilizing a predictive model based on principal component analysis (PCA) and canonical correlation analysis (CCA). Anna Leigh Rack-Gomer1,2, Joy Liau3, Thomas T. Liu1,2 1Bioengineering, UC San Diego, La Jolla, CA, United States; 2Center for Functional MRI, UC San Diego, La Jolla, CA, United States; 3School of Medicine , UC San Diego, La Jolla, CA, United States Interpretation of inter-subject differences in resting-state functional connectivity is complicated by the BOLD signals dependence on vascular factors. We found functional connectivity strength to be correlated with resting-state fluctuation amplitude (RSFA) across healthy subjects, where RSFA has previously been shown to correspond to vascular reactivity within subjects. However, we did not find RSFA to be related to either the task-related cerebral blood flow (CBF) response or baseline CBF, suggesting that RSFA does not indicate vascular differences across subjects. Instead, RSFA may reflect true differences in spontaneous neural activity, which contribute to the normal variability found in resting-state functional connectivity. Shmuel Na'aman1, Sebastien Thomas1, Mirza Baig1, Peter O'Connor1, Amir Shmuel1,2 1MNI, Dept. of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada; 2Center for MR Research, U. of Minnesota, Minneapolis, MN, United States Recent studies have demonstrated large amplitude spontaneous slow (< 0.1 Hz) fluctuations in functional-MRI (fMRI) signals in humans in the resting state. Despite the large body of human imaging literature on spontaneous activity and functional-connectivity in the resting state, the link to underlying neural activity remains tenuous. We show that spontaneous neurophysiological activity in rat S1FL includes events in which changes in local field potentials across cortical layers resemble the corresponding changes in response to sensory stimulation. These spontaneous neurophysiological events are accompanied by increases in blood oxygenation that peak approximately 5 s following the events. Willem M. Otte1,2, Rick M. Dijkhuizen2, Peter C. van Rijen1, Peter H. Gosselaar1, Maurits P.A. van Meer1,2, Onno van Nieuwenhuizen1, Kees P.J. Braun1 1Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, Netherlands; 2Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands Hemispherectomy is a last resort treatment for catastrophic hemispheric epilepsy. The remarkable motor recovery after hemispherectomy reflects the plastic capacities of the brain. We studied the remaining brain in hemispherectomized rats, 7 and 49 days post surgery using resting-state fMRI, graph analysis and interregional connectivity. The sensorimotor cortex and striatum in the healthy contralesional hemisphere exhibited significantly increased functional connectivity after surgery. The graph analysis results assume a shift toward a more regular network organization. We have shown that rs-fMRI, connectivity analyses and specific network measures can provide unique insights into functional reorganization in the remaining brain after experimental hemispherectomy. fMRI: Neuroscience Hall B Tuesday 13:30-15:30 1175. The Non-Linear Dynamic Characteristics of Olfactory BOLD ResponseΞ Christopher W. Weitekamp1, Jianli Wang1, Paul J. Eslinger2,3, Jeffrey Vesek1, Xiaoyu Sun1, James R. Connor4, Qing X. Yang1,4, Jianzhong Yin1, Martin A. Lindquist5 1Radiology, Penn State University College of Medicine, Hershey, PA, United States; 2Neurology, Penn State University College of Medicine, Hershey, PA, United States; 3Neural & Behavioral Sciences, Penn State University College of Medicine, Hershey, PA, United States; 4Neurosurgery, Penn State University College of Medicine, Hershey, PA, United States; 5Statistics, Columbia University, New York, NY, United States This study examined the dynamic nonlinear BOLD response pattern in the primary olfactory cortex (POC) and associated brain structures during an olfactory fMRI paradigm. An intricate relationship among perception threshold, sensitivity, and habituation of the human olfactory system challenges the fundamental assumption of linearity in BOLD response. The goal of this study was to emphasize an unconventional nonlinear model of BOLD response through the use of olfactory fMRI and to suggest that such dynamic characteristics may extend to other neuronal systems with a feedback mechanism, profoundly impacting fMRI data acquisition/analysis and its clinical applications. Toshiharu Nakai1, Makoto Miyakoshi1, Epifanio Bagarinao1, Masaki Yoshida2, Chikako Nakai3, Kayako Matsuo4 1Functional Brain Imaging Lab, National Center for Geriatrics and Gerontology, Ohbu, Aichi, Japan; 2Ophthalmology, The Jikei University, Tokyo, Japan; 3School of Health Sciences, Toyoshashi Sozo University, Toyohashi, Aichi; 4Psychology, National Taiwan University, Taipei, Taiwan We evaluated the effect task demand for visual processing on the age-related change of the brain activation in healthy subjects. In the elderly subjects, the % HRF in V1 was reduced by the flickering checkerboard stimuli. By a visuo-motor translation task the % HRF in BA19/7/39 was increased in the elderly, while no significant difference of % HRF was detected between the two age groups in V1. HRF analysis suggested that age-related change of % HRF may depend on the existence of neuronal network to compensate the potential functional decline according to aging. Daron Gordon Owen1,2, Collin Franklin Clarke3, Sugantha Ganapathy3, Frank S. Prato1,4, Keith S. St. Lawrence1,2 1Imaging Program, Lawson Health Research Institute, London, Ontario, Canada; 2Medical Biophysics, The University of Western Ontario, London, Ontario, Canada; 3Anesthesia and Perioperative Medicine, The University of Western Ontario, London, Ontario, Canada; 4Imaging, St. Joseph's Hospital, London, Ontario, Canada The cerebral representation of acute pain is well established, whereas that of tonic pain is not due to difficulties in applying functional imaging to prolonged stimuli. We used arterial spin labeling (ASL) to investigate the neural activation associated with tonic muscular pain. The use of ASL allows direct comparison between studies. Compared to our previous study incorporating both acute and tonic phases, we observed smaller CBF changes, and only in bilateral insula and frontal gyrus, despite similar pain levels. A likely explanation is that the acute phase of the previous study induced anxiety and distress, whereas our tonic pain stimulus did not. 1178. Age and Gender Effects on Whole Brain Cerebral Blood Flow in Adolescents Ai-Ling Lin1, Timothy Q. Duong1, Peter T. Fox1, Douglas E. Williamson2 1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States; 2Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States Both gender and have long been assumed to have effects on brain function and cerebral blood flow (CBF). However, the effects of gender and age on CBF have not well explored in adolescents. To increase our knowledge in this area, MRI techniques were employed to measure global CBF with 267 adolescents. Our result shows that significant difference in CBF was observed between 12 and 15 years of age. However, no significant main effects of gender were found in the study. The results provide better understanding of brain functions for adolescent across age and gender. 1179. A FMRI Study of Temporary Hearing Threshold Shift Piotr Bogorodzki1, Tomasz Wolak2, Krzysztof Kochanek2, Ewa Piatkowska-Janko1, Piotr Skarzynski2, Adam Pilka2, Jozef Kotus3, Andrzej Czyzewski3 1Institute of Radioelectronics, Warsaw University of Technology, Warsaw, Poland; 2Institute of Physiology and Pathology of Hearing; 3Gdansk University of Technology, Gdansk, Poland Several empirical studies have shown, that long lasting acoustic noise exposure causes on humans effect called Temporary Hearing Threshold Shift (TTS). This work presents results from 15 healthy subjects participating in a fMRI study of TTS consisting of two runs: ā££preā££ with silent GE EPI scanning and ā££postā££ identical to ā££ā££preā££, but after 15min high volume noise exposure (causing a mean 12 dB TTS effect). Group level analysis showed activations in auditory cortex (T=13.3 in lh, and 10.45 in rh). A two-sample T-test fails for post>pre contrast, however detailed ROI analysis shows differences in sub-auditory areas. Hui-jin Song1, Joo-hyun Kim1, Jeehye Seo1, Moon-jung Hwang2, Young-ju Lee2, Kyung Jin Suh3, Sung Woo Kim3, Young Hwan Lee4, Dong Soo Yoo5, Yongmin Chang1,6 1Medical & Biological Engineering, Kyungpook National University, Daegu, Korea, Republic of; 2GE healthcare, Seoul; 3Dongguk University, Gyungju; 4Radiology, College of Medicine, Catholic University, Daegu; 5Radiology, College of Medicine, Dankook University, Chunan; 6Diagnostic Radiology, Kyungpook National University, Daegu, Korea, Republic of Although the mirror neuron system has been extensively studied, no functional imaging data are currently available to gain insight in the possible difference of the mirror system between experts and novices. Therefore, the aim of the present study is to investigate the differences of activation in the mirror neuron system during viewing tool use familiar to experts between expert archers and novice subjects. Our results demonstrated that expert archers showed strong activation in the mirror neuron system during viewing videos of Western-style archery relative to inexpert control subjects. Taken together, our data consistent with previous reports suggest that human mirror neuron system could contain representations of tool use and expand motor repertoire with tool use experiences. 1181. Localization of the Hand Motor Area Using BOLD and ASL FMRI Marco Pimentel1, Pedro Vilela2, Inźs Sousa3,4, Patricia Figueiredo3 1Faculdade de Ciźncias e Tecnologia, Universidade Nova de Lisboa, Lisbon, Portugal; 2Imaging Department, Hospital da Luz, Lisbon, Portugal; 3Instituto Superior Técnico, Lisbon, Portugal; 4Healthcare Sector, Siemens, S.A., Portugal Previous studies have shown that ASL-based fMRI exhibits better spatial specificity than the most commonly used BOLD contrast. Here, we compared the localization of the hand motor area obtained by simultaneous ASL-BOLD fMRI and standard BOLD fMRI at 3T with well established anatomical landmarks, in a group of 15 healthy subjects. Our results indicate that the localization of the hand motor area obtained using ASL fMRI is significantly less variable and closer to the hand motor cortex anatomical landmarks than the one produced by BOLD fMRI. This supports the notion that ASL may more accurately localize brain activation than BOLD. 1182. Understanding Consciousness from Information and Integration Within the Thalamocortical System Xiaolin Liu1, Jingsheng Zhou2, Anthony G. Hudetz3, Shi-Jiang Li1 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 2Rehabilitation Department, Xuanwu Hospital Capital Medical University, Beijing, China; 3Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States Understanding the neural mechanisms of consciousness requires identification of the nature of contributions from each of the potential neural correlates, which together generate a complete cognitive experience. We examined the specific and nonspecific thalamic connections in the brain based on the neuroanatomical findings implicating their respective functional roles in sustaining information and integration, which are essential to consciousness. Our results endorse the view that the thalamocortical system is essential to consciousness, and support the hypothesis that the nonspecific thalamic connections largely reflect brain regions that are responsible for information integration, potentially sustaining various awareness functions. 1183. Examining Structure and Function in a Cognitive Task Jeffrey Thomas Duda1, Corey McMillan, Murray Grossman, James Gee 1Bioengineering, University of Pennsylvania, Philadelphia, PA, United States Structure and function are examined in the language network with DT-MRI and BOLD fMRI during a cognitive task. Activated cortical regions are identified and used to determine activation levels in each subject. Additionally, the regions are used to identify fiber tracts of interest. Canonical correlation analysis is used to identify correlations between functional activation and average fractional anisotropy in the fiber tracts. For each correlation found, the highest weightings are found for cortical regions and a tract that connects to that region. Dave Langers1, Pim van Dijk1 1Otorhinolaryngology, University Medical Center Groningen, Groningen, Netherlands Scanner acoustic noise may detrimentally affect stimulus/task-evoked neural responses in fMRI. This has been reported for the unimodal and associative auditory systems, but also for the default mode network and other brain systems. In the current experiment, the effects of scanner noise in resting state fMRI are studied. We find that similar independent components may be extracted with and without background scanner noise, both during active and resting states. However, the overall strength, spatial extent, and temporal dynamics of various neural components are affected by the presence of background noise. Our results both corroborate and extend previous findings in literature. More detailed specific findings for various brain systems will be presented. 1185. Neural Correlates of Feigned Hearing Bradley McPherson1, Wayne Wilson2, David Copland3,4, Katie McMahon5 1Division of Speech and Hearing Sciences, Hong Kong University, China; 2Division of Audiology, University of Queensland, Australia; 3Centre for Clinical Research, University of Queensland, Australia; 4School of Health and Rehabilitation Sciences, University of Queensland, Australia; 5Centre for Magnetic Resonance, University of Queensland, Brisbane, Queensland, Australia Can we use patterns of brain activity to detect when someone is feigning a hearing loss? To answer this question, we asked 15 adult participants to respond to pure tones and simple words correctly, incorrectly, randomly, or with the intent to feign a hearing loss. 1186. An FMRI Study of Memory Performance in Type 2 Diabetes Mellitus: A Twin Study Amanda Wood1, Jian Chen2,3, Thanh G. Phan2, Kimberlea Cooper2, Stacey Litras2, Srikanth Velandai2 1Developmental and Functional Brain Imaging,Critical Care and Neuroscience, Murdoch Childrens Research Institute, Melbourne, VIC, Australia; 2Stroke and Ageing Research Group, Department of Medicine, Monash University, Melbourne, VIC, Australia; 3Developmental and Functional Brain Imaging,Critical Care and Neuroscience , Murdoch Childrens Research Institute, Melbourne, VIC, Australia Type 2 Diabetes mellitus (DM) is linked to a greater risk of dementia, but the underlying mechanisms and brain regions involved are unknown. We conducted a co-twin (DM/non DM) case-control study of fMRI activation during a visual memory task. Non DM twins showed greater activation of temporal, parietal and occipital cortices suggesting involvement of these areas in DM pathology. Animal fMRI Hall B Wednesday 13:30-15:30 Christof Baltes*1, Simone Bosshard*1, Thomas Mueggler1,2, Markus Rudin1,3 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; 2Pharmaceutical Research Neuroscience, F. Hoffmann-La Roche Ltd., Basel, Switzerland; 3Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland BOLD-fMRI in mice using electrical forepaw stimulation was performed with a cryogenic transceive RF probe and a room-temperature receive-only surface coil. The effect of the increased sensitivity of the cryogenic probe on detecting BOLD responses was analyzed. In fMRI experiments, a gain in image SNR and in temporal SNR of a factor of 3.10 and 1.77 was found, respectively. As further optimization parameter adjusting the thermal shield temperature of the cryogenic probe allows for altering baseline perfusion and accordingly BOLD responses. Cryogenic cooling reduces BOLD signal variations by a factor of 1.59 and therefore increases the statistical power of fMRI. 1188. Investigating Color Vision Using FMRI: Rodent Vs Primate Andy Paul Salzwedel1, Matt Mauck2, James Kuchenbecker3, Chris Pawela1, James Hyde1, Maureen Neitz3, Jay Neitz3 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 2Department of Ophthalmology, Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, United States; 3Ophthalmology, University of Washington, Seattle, WA, United States In a comparative study, the visual pathways of two different animal models (rodent vs primate) were probed using high field strength (9.4T) fMRI. The primary goal of this research was to assay the color vision systems of these two species in hope of demonstrating the evolutionary homology thereof. Here we present several techniques that combine to form a unique overall method for probing this pathway; pharmacological intervention (AP4), precession fMRI compatible LED based stimuli, and intra-brain controls. 1189. Detectability of the BOLD Signal Jozien Goense1, Hellmut Merkle2, Nikos Logothetis1,3 1Department of Physiology of Cognitive Processes, Max-Planck Institute for Biological Cybernetics, Tuebingen, Germany; 2Laboratory of Functional and Molecular Imaging, NINDS, NIH, Bethesda, MD, United States; 3Division of Imaging Science and Biomedical Engineering, University of Manchester, Manchester, United Kingdom The BOLD signal is a weak signal, and hence if no BOLD signal is found in an area this does not necessarily mean there is no neural activity in that area. Signal dropout, artifacts, instability, physiological noise, RF-coil inhomogeneity etc. can all reduce the SNR locally leading to decreased detectability of the BOLD signal Here we illustrate that calculation of the spatial distribution of the detection for a given set of experimental conditions allows us to estimate the confidence by which absence of an fMRI signal can be interpreted as an absence of neural activity. 1190. BOLD FMRI of Anesthetized Baboons Hsiao-Ying Wey1,2, Jinqi Li1, M. Michelle Leland3, Lisa Jones3, C Akos Szabo4, John W. Roby1, James T. Scribner1,2, Ghzawan M. Kroma2, Peter T. Fox1, Timothy Q. Duong1,2 1Research Imaging Institute, UT Health Science Center at San Antonio, San Antonio, TX, United States; 2Radiology, UT Health Science Center at San Antonio, San Antonio, TX, United States; 3Laboratory Animal Resources, UT Health Science Center at San Antonio, San Antonio, TX, United States; 4Neurology, UT Health Science Center at San Antonio, San Antonio, TX, United States This study reports a robust anesthetized baboon model for BOLD fMRI studies on a clinical 3T human MRI scanner. BOLD fMRI of visual and somatosensory/motor stimulations in anesthetized baboons were investigated. Comparisons of BOLD fMRI sensitivity were made between isoflurane and ketamine anesthetics with and without paralytics. To our knowledge, this is the first report on baboon BOLD fMRI of visual and somatosensory/motor. Junjie V. Liu1, Nicholas A. Bock2, Ara Kocharyan1, Julie Mackel1, Afonso C. Silva1 1NINDS, National Institutes of Health, Bethesda, MD, United States; 2Medical Physics, McMaster University, Hamilton, ON, Canada By combining BOLD fMRI with T1 mapping, here we study the ipsilateral responses in somatosensory cortex of awake marmosets. Our results show a surprising spatial mismatch between contralateral and ipsilateral representations of the same body part.
Arabinda Mishra1, Baxter P. Rogers1, Barbara Dillenburger1, Kevin Wilson1, Feng Wang1, John C. Gore1, Li Min Chen1 1Radiology & Radiological Science, VUIIS, Nashville, TN, United States Correlations between resting state BOLD signals in widely distributed brain regions is a key signature of consciously driven mental activity in humans. In this work we attempted to explore if a fine scale functional connectivity can be detected within the anatomically well defined primary somatosensory cortex (SI) at high field and whether the functional connectivity reflects anatomical hierarchical relationships in anesthetized monkeys. We found that functional connectivity exists among anatomically interconnected cortical subregions (areas 3a, 3b, 1 and 2) within SI without the involvement of consciousness (or alertness), and the strengths of the correlation among these subregions reflect the strength of their underlying anatomical connections. 1193. fMRI Analysis of the Olfactory Responses to Home-Stream Water in Sockeye Salmon Hiroshi Bandoh1, Ikuhiro Kida2, Hiroshi Ueda1,3 1Division of Environmental Science Development, Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido, Japan; 2Integrated Neuroscience Research Team, Tokyo Institute of Pschiatry, Setagaya-ku, Tokyo, Japan; 3Laboratory of Aquatic Ecosystem Conservation, Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Hokkaido, Japan The odor-information processing involved in olfactory imprinting and homing of the home-stream odor in the central nervous system of salmon has not been completely elucidated. In this study, to investigate this information-processing mechanism, we used BOLD fMRI to measure the response to home-stream water in the olfactory bulb and telencephalon of sockeye salmon. The presence of BOLD signals in the dorsal area of the telencephalon indicated that the odor information for home-stream water was processed in a specific area in the telencephalon of sockeye salmon. Juha-Pekka Niskanen1,2, Antti Airaksinen1, Jari Nissinen1, Asla Pitkänen1, Olli Gröhn1 1Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, Kuopio, Finland; 2Department of Physics, University of Kuopio, Kuopio, Finland Traumatic brain injury (TBI) is a major cause of death and disability worldwide. In this study, 10 rats with TBI and 6 sham operated controls were imaged during electrical stimulation of the forepaws before TBI and 1, 2 and 8 weeks after TBI. fMRI with forepaw stimulation was able to reveal functional deficit after TBI in the somatosensory cortex outside of the main lesion and also detect partial sensory recovery 8 weeks after TBI. The results suggest that fMRI could serve as a non-invasive user independent tool to evaluate functional recovery after TBI. Christopher James Martin1, Jason Berwick2, Ying Zheng2, John Mayhew2 1Radiation Oncology and Biology, University of Oxford, Oxford, Oxfordshire, United Kingdom; 2University of Sheffield The aim of this work was to investigate the spatiotemporal changes in hemodynamics that underlie fMRI signal changes in response to stimulus evoked changes in neuronal activity. We used optical imaging spectroscopy in an un-anesthetized rat model, to provide measures of changes in blood volume and oxygenation at higher spatial and temporal resolution than possible with fMRI, without the potentially confounding effects of anesthesia. We found a complex spatiotemporal hemodynamic response function, consisting of both increases and decreases in blood volume and oxygenation as well as oscillatory response components. We discuss the implications of these findings for fMRI. 1196. BOLD Changes in Somatosensory Cortex of Malnourished Rats R Martin1, R Godinez1, Alfredo O. Rodriguez1 1Departament of Electrical Engineering, Universidad Autonoma Metropolitana Iztapalapa, Mexico, DF, Mexico Malnutrition is a main public health problem in developing countries. Incidence is increasing and the mortality rate is still high. Functional Magnetic Resonance Imaging (BOLD) was used for mapping brain activity of malnourished rats. The food competition method was applied to a rat model to provoke malnutrition during lactation. The vibrissae-barrel axis was also used due to its advantages for studying structure, function, development and plasticity within the somatosensory cortex. BOLD response changes caused by the trigeminal nerve stimulation on brain activity of malnourished and control rats were obtained at 7T. Results showed a major neuronal activity in malnourished rats. Dewen Yang1, Zhiyong Xie1, James Goodman1, Anne Burkholder2, Nancy Poy2 1BioImaging COE, Pifizer Global Research & Development, Groton, CT, United States; 2WW Comparative Medicine, Pifizer Global Research & Development, Groton, CT, United States The neurovascular response to electric forepaw stimulation (EFS) was observed with BOLD signal in the contralateral somatosensory cortex in 11 rats with normal blood gas physiology under alpha-chloralose anesthesia. Serial CBF maps were also acquired during EFS in a subset of these rats. BOLD activation and CBF maps showed elevated blood flow in the contralateral somatosensory cortex at the time of stimulation, after which the regional activation and increases in CBF spread to cortex in the ipsilateral hemisphere. Simone Claudia Bosshard1, Christof Baltes1, Markus Rudin1,2 1Institute for Biomedical Engineering, ETH Zürich, Zurich, Switzerland; 2Institute of Pharmacology and Toxicology, University of Zurich, Zurich, 8057, Switzerland Electrical stimulation of the forepaws is a widely used stimulation paradigm in functional magnetic resonance imaging (fMRI). We used transgenic mice lacking the voltage-gated sodium channel Nav 1.7 specifically at the nociceptors (Nav1.7R-/-) to study altered pain sensitivity. Nav1.7R-/-, WT littermates and WT animals of our lab were examined using BOLD fMRI. The detected BOLD signal changes of the Nav1.7R-/- animals were significantly reduced as compared to the two WT groups. This is in line with behavioral data reported for these mice. This proves our method to be a valuable tool to non-invasively study pain processing in mice. Nathalie Just1,2, Hanne Frenkel3, Rolf Gruetter3,4 1LIFMET, CIBM, EPFL, Lausanne, Switzerland; 2Department of Radiology, UNIL, Lausanne, Switzerland; 3LIFMET, EPFL, Lausanne, Switzerland; 4Department of Radiology, UNIL and HUG, Lausanne and Geneva, Switzerland The present study examined the BOLD fMRI response of the rat barrel cortex upon sustained trigeminal nerve stimulation. Moreover, the alterations in the barrel cortex metabolite concentration due to prolonged functional activation were measured using 1H-MRS at 9.4T. The results demonstrate that sustained BOLD responses can be obtained reproducibly in the rat barrel cortex following prolonged trigeminal nerve stimulation. Furthermore, preliminary functional MRS (fMRS) results show changes in several metabolites in the barrel cortex and in particular an increase in lactate levels during barrel cortex activation. 1200. The Utility of FMRI in Measuring Brain Plasticity Following Peripheral Nerve Injury Christopher Paul Pawela1,2, Bharat B. Biswal3, Rupeng Li2, Anthony G. Hudetz4, Hani S. Matloub1, James S. Hyde2 1Department of Plastic Surgery, Medical College of Wisconsin, Milwaukee, WI, United States; 2Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 3Department of Radiology, University of Medicine and Dentistry of New Jersey, Newark, NJ, United States; 4Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States In this study brain reorganization following nerve injury and repair was followed for a twelve week period with BOLD fMRI in a rat model. Primary sensory functional return progressed over the entire study period whereas thalamic areas did not functionally return until the twelve week time point. This study demonstrates the utility of using BOLD fMRI as a substitute for conventional electrophysiology in studies of brain plasticity and has many applications outside of peripheral nerve injury and repair. Jennifer I. Wood1,2, Suresh E. Joel1,3, Michael T. McMahon1,2, James J. Pekar1,2, Galit Pelled, 2,4 1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States; 2The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 3The Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 4F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute , Baltimore, MD, United States Human and animal studies suggest the involvement of the transcallosal projection in shaping neuroplasticity following injury may be crucial in dictating the rehabilitation probability. This study was designed to investigate the role of the transcallosal pathways in mediating neuroplasticity following injury in a rat model of sensory deprivation. Using fMRI, we have studied the time course and the age-dependency of which the transcallosal projections effect cortical reorganization. The results demonstrate that the transcallosal projections involvement in neuroplasticity varies dependent on the age and the time following the injury and may introduce a critical consideration when choosing the right rehabilitation strategy. 1202. BOLD FMRI Assessment of the Functional Response to Taste Stimulation in Rat Brain Ikuhiro Kida1, Yoko Hoshi1, Yoshinobu Iguchi1 1Integrated Neuroscience Research Team, Tokyo Institute of Pschiatry, Setagaya-ku, Tokyo, Japan Some aspects of taste information processing have not been conclusively clarified, such as the process by which the gustatory cortex uses spatial codes to characterize taste information.We used BOLD fMRI measurements obtained at 7 T in an animal system to investigate the process by which taste information is encoded. Sucrose yielded a reproducible BOLD signal increase in the gustatory cortex. During taste stimulation, BOLD signals were also detected in the lip region of the primary somatosensory cortex, secondary somatosensory cortex, and amygdalae. This is the first study that used BOLD fMRI to observe gustatory activation in the rat brain. Pai-Feng Yang1, You-Yin Chen2, Jyh-Horng Chen1, Chen-Tung Yen3 1Electrical Engineering, National Taiwan University, Taipei, Taiwan; 2Electrical Engineering, National Chiao-Tung University, Hsinchu, Taiwan; 3Zoology, National Taiwan University, Taipei, Taiwan This paper proposes a novel flexible MRI-compatible microelectrode array that leverages the stimulation and recording properties for neuroscience application. We perform functional MRI to investigate the cortico-striato-thalamal circuit with thalamic stimulation. Significant positive BOLD responses were observed in receptive field in upper lip region (S1ULp), barrel field (S1BF) and secondary somatosensory cortex (S2). Negative BOLD responses were revealed in caudate putamen (CPu). We inferred a limbic cortico-striatal loop might exist. Salem Boussida1, Amidou Traore2, Jean-Pierre Renou2, Franck Durif3 1INRA, UR370 QuaPA/NMR plateforme, Centre Clermont-Ferrand/Theix, F-63122 Saint Genčs Champanelle, France; 2INRA, UR370 QuaPA/NMR plateforme, Centre Clermont-Ferrand/Theix, F-63122 Saint Genčs Champanelle, France; 3CHU Clermont-Ferrand, Service de Neurologie, Clermont-Ferrand, F-63001, France. Combination of blood oxygen level-dependent functional magnetic resonance imaging (BOLD fMRI) and electrical hindpaw stimulation has been used as a standard model to study the somatosensory pathway and brain rehabilitation in rats. In the present study, we examined the feasibility of performing BOLD fMRI experiments on rat to investigate the activity of the basal ganglia (BG)-cortex circuit associated to hindpaw sensitive stimulation. These findings will have relevance in the fMRI studies dealing with physiopathology of neurodegenerative diseases such as Parkinson Patrick C. Hettinger1, Rupeng Li2, Ji-Geng Yan1, Hani S. Matloub1, Young R. Cho1, Matthew L. Runquist2, Christopher P. Pawela1, James S. Hyde2 1Plastic Surgery, Medical College of Wisconsin, Milwaukee, WI, United States; 2Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States The purpose of this study is to further define the ratunculus by observing cortical activity using BOLD fMRI during direct stimulation of the C7 nerve root. In this study, 7 Sprague-Dawley rats underwent implantable electrode placement on the C7 nerve root. BOLD response to nerve stimulation was then studied using a Bruker 9.4T MRI scanner. C7 nerve stimulation resulted in a small amount of activation in the S1FL region along with a large amount of activation within the M1/M2 regions. These findings are similar to the sensory and motor distributions described in human C7 nerve root literature. Ursula I. Tuor1, Jennifer Vuong2, Jeffrey F. Dunn3, Tadeusz Foniok1, Dave Kirk4, Amy H. Henderson2, G Campbell Teskey2,5 1Institute for Biodiagnostics (West), National Research Council of Canada , Calgary, Alberta, Canada; 2Psychology, University of Calgary; 3Radiology, University of Calgary; 4Experimental Imaging Centre, University of Calgary; 5Anatomy and Cell Biology, University of Calgary, Calgary, Alberta, Canada We used functional magnetic resonance imaging (fMRI) in rats to investigate whether following 20 repeatedly elicited seizures there are seizure-induced alterations in the somatosensory maps to forepaw stimulation. We observed increased areas of activation both acutely (1-3 days) and chronically (3-5 weeks) after experimental kindling induced epilepsy. The data indicate that there is considerable neuroplasticity and development of new pathways during the progression of epilepsy. Whether comparable plasticity of cortical maps is present in humans should be tested using fMRI in future studies, considering that such seizure-induced changes may be involved in producing interictal behavioural disturbances.
1207. Layer-Specific FMRI of Photic Stimulation in the Rat Retina at 11.7 T Yen-Yu Ian Shih1, Bryan H. De La Garza1, William J. Lavery1, Eric R. Muir1,2, Timothy Q. Duong1 1Research Imaging Institute, Ophthalmology/Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States; 2Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States The retina is about 276 micron thick including the choroid and has highly organized laminar structures. This study reports, for the first time, the feasibility of high-resolution blood-volume fMRI to image layer specific (retinal and choroidal) visual responses in the rat retina at 11.7T up to 40x40x600 micron nominal resolution. Given that the choroid is behind the retina and the retinal pigment epithelium, it is generally inaccessible by optical techniques. Blood-volume fMRI thus could provide a unique means to evaluate lamina-specific functional changes in the rat retina where many retinal disease models are readily available. 1208. Pass-Band Balanced Steady State Free Precession Functional MRI of the Mouse Retina Eric Raymond Muir1,2, Sung-Hong Park3, Timothy Q. Duong2 1Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States; 2Research Imaging Institute, Ophthalmology/Radiology, UT Health Science Center San Antonio, San Antonio, TX, United States; 3Research Imaging Institute, Radiology, UT Health Science Center San Antonio, San Antonio, TX, United States BOLD fMRI of the thin retina with the widely used EPI acquisition is challenging because the eye is a region of large magnetic inhomogeneity and high-resolution EPI is pushing the limits of gradient performance, resulting in susceptibility-induced signal drop out and image distortion. To overcome these limitations, we implemented a pass-band balanced steady state free precession (bSSFP) sequence for fMRI of the mouse retina at 45x45x500 µm. bSSFP has comparable temporal resolution and SNR per unit time as EPI, without the artifacts common in EPI. bSSFP fMRI could reliably detect layer-specific responses to hypoxic challenge in the mouse retina. John Lowry1, Karen Griffin2, Stephen McHugh3, Nicola Sibson4 1Department of Chemistry, National University of Ireland, Maynooth, Ireland; 2University College Dublin, Ireland; 3Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom; 4Gray Institute for Radiation Oncology and Biology, University of Oxford, Oxford, Oxfordshire, United Kingdom Long-term in-vivo electrochemistry (LIVE) enables real-time measurement of brain metabolites. Here we have simultaneously obtained BOLD fMRI and amperometric LIVE tissue oxygen data from rat cerebral cortex, during both increases and decreases in inspired oxygen. BOLD and tissue oxygen measurements demonstrated close correlation during both complete oxygen removal (negative responses) and increases in inspired oxygen (positive responses). Our findings demonstrate the feasibility of obtaining real-time metabolite information during fMRI acquisition. The results show that the BOLD signal provides a close correlate of the tissue oxygen dynamics or, alternatively, that tissue oxygen concentration can predict the magnitude of the BOLD response. 1210. Evaluation of Cerebral Energy Demand During Graded Hypercapnia Stefan Alexandru Carp1, Maria Angela Franceschini1, David Alan Boas1, Young Ro Kim1 1Martinos Center/Radiology, Massachusetts General Hospital, Charlestown, MA, United States The cerebral metabolic rate of oxygen (CMRO2) is a physiological parameter closely linked to neural activation as well as to various disease states. Hypercapnic calibration is used to calibrate the BOLD-CBF-CBV relationship under the assumption of iso-metabolic blood flow increase during CO2 inhalation. Simultaneous near infrared optical measurements of cerebral blood volume, blood flow and oxygen extraction can also be used to monitor CMRO2 changes, albeit at low spatial resolution. We use these optical measurements during graded hypercapnia to test the iso-metabolic assumption, and demonstrate an apparent increase in brain metabolism at higher inhaled CO2 levels. 1211. Dissociation of BOLD and Local Field Potentials Wen-Ju Pan1, Matthew Magnuson1, Garth Thompson1, Waqas Majeed1, Dieter Jaeger2, Shella Keilholz1 1BME, Georgia Institute of Technology / Emory University, Atlanta, GA, United States; 2Biology, Emory University, Atlanta, GA, United States To examine what extent consistence of the measurements between BOLD fMRI and local field potential (LFP), we evaluated BOLD and LFP simultaneously in rat somatosensory cortex with a combined measurement technique. The preliminary results indicated a dissociation between BOLD and LFP during low-level neural activity, which might mirror the limitation of neurovascular coupling, the bridge between BOLD and neural activity. 1212. TR and TE Dependence on Low Frequency BOLD Fluctuations Matthew Evan Magnuson1, Wenju Pan1, Waqas Majeed1, Garth Thompson1, Shella Keilholz1 1Biomedical Engineering, Georgia Institute of Technology / Emory University, Atlanta, GA, United States Low freqnecy fluctuations in resting state BOLD data have often been used to map functional connectivity in the rat brain. These low frequency BOLD fluctuations contain contributions from CBF, CBV, and CMRO2. Each of these components have unique physiological time signatures and effective echo times; therefore, modification of the TR and TE used in resting state scans should result in altered contributions from each BOLD component. In this study we examine the dependence of the selection of the TR and TE variables on low frequency resting state data. Xiao Wang1, Xiao-hong Zhu1, Yi Zhang1, Wei Chen1 1Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, United States The feasibility of saturation-recovery T1 MRI for imaging and quantifying absolute CBF change was further tested at 9.4T using a rat hypercapnia model on two aspects: using diffusion gradients to investigate macrovascular inflow contribution; and slab saturation with varied thickness to test the effects of blood transit distance on measuring CBF. The results indicate that the outcomes of CBF changes induced by hypercapnia were coincident with the literature reports, and not significantly affected by large-vessel inflow effect and blood transit time. The overall results demonstrate that the saturation-recovery T1 MRI is sensitive to microvascular perfusion; it provides a noninvasive and reliable imaging approach for studying cerebral perfusion changes induced by physiology or pathology perturbation. 1214. In Vivo MR Measurement of Arterial Pulse Pressure in the Murine Aorta Volker Herold1, Marco Parczyk1, Wolfgang Rudolf Bauer2, Eberhard Rommel1, Peter Michael Jakob1 1Department of Physics EP5, University of Wuerzburg, Wuerzburg, Bayern, Germany; 2Medizinische Universitätsklinik, University of Wuerzburg, Wuerzburg, Bayern, Germany Mouse models are increasingly used to investigate functional and cardiovascular parameters. In this work we present an approach to noninvasively estimate the arterial pulse pressure by measuring the time dependant blood flow pulse and the local pulse wave velocity. By determining the complex impedance with solutions from the Navier-Stokes equations for incompressible fluids, the pressure pulse could be calculated from the accordant flow pulse. The present results are in good agreement with results from the literature obtained by invasive methods. Lubos Budinsky1, Benito de Celis Alonso2, Marina Sergejeva1, Andreas Hess2 1Institute of Pharmacology, FAU, Erlangen, Germany; 2Institute of Pharmacology, FAU, Erlangen, Germany The undesired motion, which is correlated with the fMRI paradigm (often present in experiments which are using mechanical stimulation or painful stimulus) can create false areas of an activity, which could remain real BOLD activity areas and a signal time course. Here we present series of fMRI experiment with phantoms and dead animals to which the motion was induced by using an air driven device integrated into the animal cradle. Using results from these experiments we suggest strategy, how to deal with this problem even if conventional motion correction algorithm are not able to remove these false areas completely. 1216. Functional MRI in the Rat at 9.4 T and 16.4 T David Zsolt Balla1, Hannes M. Wiesner1, Gunamony Shajan1, Rolf Pohmann1 1High Field Magnetic Resonance Center, Max Planck Insitute for Biological Cybernetics, Tübingen, Baden-Württemberg, Germany Functional MRI (fMRI) in animals at high magnetic fields keeps expanding our knowledge about the basics of neural processing but the specificity of the fMRI-signal is still under ongoing investigation. Yet, as the signal to noise ratio in MRI depends linearly on the magnetic field strength and calls for even stronger magnets for the detection of even smaller anatomical details, the relation between the functional MR-response and field strength can only be approximated with complex models. In this study the blood oxygenation dependent (BOLD) effect was measured and compared at 9.4 T and 16.4 T in the same animal with segmented gradient-echo (GE) and spin-echo (SE) echo planar imaging (EPI) sequence using optimal echo times for the respective field. Furthermore, high resolution fMRI acquisition at 16.4 T was performed up to a 50 µm in-plane accuracy and for an 8 s temporal resolution without the use of cryo-coils or coil-arrays. Fuqiang Zhao1, Denise Welsh1, Mangay Williams1, Alexandre Coimbra1, Mark O. Urban2, Richard Hargreaves2, Jeffrey Evelhoch1, Donald S. Williams1 1Imaging Department, Merck Research Laboratories, West Point, PA, United States; 2Neuroscience Department, Merck Research Laboratories, West Point, PA, United States In central nervous system, neuronal activity generally leads to increases in local venous blood oxygenation level (BOLD), cerebral blood flow (CBF), and cerebral blood volume (CBV). However, previous studies have reported that the neural activity in rat caudate putamen (CPu) during noxious electrical stimulation (NES) of paws causes BOLD and CBV decreases. To further understand the specific hemodynamic response in this anatomical structure and its temporal characteristics, BOLD, CBV, and CBF fMRI studies were performed in a rat brain slice containing the CPu. Our results suggest that the neural activity in the CPu during NES causes decreases in CBV and CBF, and an increase in CMRO2 which lasts >2 minutes after stopping the NES. 1218. fMRI at 17.6 T and Optical Fiber-Based Ca2+-Imaging in Rodents Albrecht Stroh1, Florian Schmid2, Afra Wohlschlaeger3, Valentin Riedl4, Jenny Kressel3, Cornelius Faber2 1Department of Neuroradiology, Technical University Munich, Munich, Germany; 2Institute for Clinical Radiology, University Hospital Münster, Münster, Germany; 3Department of Neuroradiology, Technical University Munich, Germany; 4Department of Neurology, Technical University Munich, Germany n this study we tested the feasibility of rat fMRI at highest field strength in combination with an implanted optical fiber. We aim for the combination of fiber based optical Ca2+ imaging with functional magnetic resonance imaging (fMRI) at 17.6 T in vivo. We increased the temporal resolution of fMRI to 20 ms by applying k-space segmentation. Additionally, we conducted fiber-based Ca2+ imaging in mice upon electric forepaw stimulation, detecting neuronal population activity. Our study indicates that a multimodal approach combining a global method like fMRI with a spatially confined, highly specific method as optical Ca2+ imaging becomes amenable. Yoshiyuki Hirano1, Alan P. Koretsky2, Afonso C. Silva1 1CMU, LFMI, NINDS, NIH, Bethesda, MD, United States; 2FMMS, LFMI, NINDS, NIH, Bethesda, MD, United States We investigated the laminar dependence of cortico-cortical interactions induced by paired bi-lateral somatosensory stimulation in α-chloralose anesthetized rats. When compared to the response obtained at 0 ms ISI, the BOLD percent signal change in the S1FL responding to the late stimulus was decreased by 47 % at 40 ms ISI. The degree of suppression in layers III to V was stronger than suppression of fMRI changes in layers I-II and in bottom of layer VI. Our data shows that BOLD fMRI has sufficient spatial and temporal resolution to study cortical circuits, within functional columns and layers. Animal fMRI: Pharmacologic Intervention Hall B Thursday 13:30-15:30 1220. Anesthesia with Alpha-Chloralose in Rats: It Can Be Used for Longitudinal FMRI Studies Benito de Celis Alonso1, Tanya Makarova1, Andreas Hess1 1Pharmacology and Toxicology, FAU Erlangen Nuremberg, Erlangen, Bayern, Germany Animal experimentation in neurosciences requires the use of anesthetics for animal welfare and cooperation. Two of the most widely used anesthetics for functional magnetic resonance imaging (fMRI) of animals are Isofluorane (Iso) and Alpha-Chloralose (AC). Iso is an volatile drug shown to be suitable to obtain fMRI images at low concentrations(1). AC is an injectable anesthetic with strong functional-metabolic coupling but can create physiological problems. Therefore, it has been used as a non recoverable. There are studies were AC was used on human patients and others were AC was used to anaesthetize and recover dogs and cats (2,3). To our knowledge, the non-recoverable concept has not been challenged properly for fMRI. Here we present a protocol for AC anesthetic preparation and a fMRI study that shows that AC can be used as a recoverable anesthetic and has no effects on the fMRI results when animals are reused. Furthermore parallel behavioral studies on recovered rats show no effect on their brain and motor function. 1221. Noradrenergic Modulation of Auditory Processing in the Songbird Brain. Colline Poirier1, Tiny Boumans1, Michiel Vellema1, Geert De Groof1, Marleen Verhoye1, Jacques Balthazart2, Annemie Van der Linden1 1Bio-Imaging Lab, Antwerp, Belgium; 2GIGA Neurosciences, Ličge, Belgium Song learning in songbirds shares a large number of features with human speech acquisition. The songbird brain is thus an excellent model to study the neural bases of vocal learning and complex sound processing. The aim of this spin-echo BOLD fMRI study was to investigate the role of noradrenalin in conspecific songs and birds own song perception. Depletion of noradrenergic inputs resulted in an enhanced differential activation by socially relevant auditory stimuli in the secondary auditory regions of the songbird brain. These results suggest that noradrenalin might play an inhibitory role in song discrimination. 1222. Role of Nitrite in Neurovascular Coupling: Nitric Oxide-Dependent and Independent Mechanisms Barbora Piknova1, Ara Kocharyan2, Alan N. Schechter1, Afonso C. Silva2 1National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States; 2National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States In addition to classic role of vasodilator, nitric oxide (NO) also acts as a neurotransmitter. NO role in neurovascular coupling and the possibility to restore the proper brain hemodynamics after its impairment in various NO-deficiency related diseases is of major importance. We studied the fMRI response to forepaw stimulation on į-chloralose anesthetized Sprague-Dawley rats at baseline, with NO production attenuated by nNOS inhibition and after NO and nitrite distribution. We found that exogenous NO and nitrite restore neurovascular response and that nitrite is more effective than direct NO donor. We hypothesize about additional vasodilatory pathways in case of nitrite metabolism. Kevin Sean Murnane1, Leonard Lee Howell1 1Neuroscience, Emory University, Atlanta, GA, United States Both cocaine and methylenedioxymethamphetamine (MDMA) are drugs with a high propensity for abuse yet they have distinct behavioral and neurochemical effects. We compared the changes in blood oxygenation elicited by cocaine (0.3 mg/kg, i.v.) and MDMA (0.3 mg/kg, i.v.) in rhesus monkeys using BOLD fMRI. The effects of cocaine were localized to dorsal prefrontal cortex (PFC) whereas MDMAs were localized to ventral PFC. Therefore, the neural circuitry engaged by these compounds appears to regulate their behavioral effects. As such, the use of fMRI allows for a novel approach to determine the mechanism of drugs of abuse. 1224. De Novo Buprenorphine Phmri Effects in Conscious Rats Parallels Brain Activation in Humans Lino Becerra1,2, Pei-Ching Chang1, James Bishop1, Jaymin Upadhyay1, Julie Anderson1, Gautam Pendse1, Smriti Iyengar3, Alexandre Coimbra4, Richard Baumgartner4, Adam Schwarz3, Jeffrey Evelhoch4, Erci Nisenbaum3, Brigitte Robertson5, Thomas Large5, David Bleakman3, Richard Hargreaves4, David Borsook1,2 1Imaging Consortium for Drug Development, McLean Hospital, Belmont, MA, United States; 2A A Martinos Center for Biomed. Imaging, MGH, Harvard Medical School, Charlestown, MA, United States; 3Eli Lilly and Co., Indianapolis, IN, United States; 4Merck and Co, West Point, PA, United States; 5Sepracor Inc., Marlborough, MA, United States fMRI studies of rodents are confounded by the use of anesthetics, especially for the study of analgesics. Furthermore, there are no studies comparing pharmacological brain effects in humans and rodents of the same analgesics. In this work, we present results of pharmacological MRI (phMRI) of an opioid analgesic (buprenorphine) in conscious rats and compare the brain activations with results obtained in humans. Although brain structure and function differ between humans and rodents, some parallelism does exist and this thesis underpins much pre-clinical research. Translational results as presented here have the potential to bridge pre-clinical with clinical imaging studies. Kim O'Toole1, Diana Cash1, Steve C R Williams1, Po-Wah So1 1Neuroimaging Department, Institute of Psychiatry, KCL, London, United Kingdom Glucosensing neurones regulate membrane potential and firing rates in response to ambient glucose levels, and generally located in areas involved in neuroendocrine function, nutrient metabolism and energy homeostasis. Using BOLD-MRI, we have studied the effects of a single intraperitoneal glucose tolerance dose in the brain of a fasted rat model. Glucose induced BOLD-MRI signal increases in various regions of the brain, including the hypothalamus and hippocampus, which are known to contain glucosensing neurones. Thus, BOLD-MRI may be used to a non-invasive tool assess the functional role of nutrients in the brain under different physiological states.
1226. Effect of the Novel Anti-Depressant Agomelatine Determined by Pharmacological MRI in the Rat. Karen Elizabeth Davies1, Inna V. Linnik1, Shane Mckie2, Jennifer A. Stark3, Simon Luckman3, Laure Sequin4, Elisabeth Mocaer4, Mark Millan4, Bill Deakin2, Steve R. Williams1 1Imaging Science & Biomedical Engineering, University of Manchester, Manchester, United Kingdom; 2Neuroscience and Psychiatry Unit, University of Manchester, Manchester, United Kingdom; 3Faculty of Life Science, University of Manchester, Manchester, United Kingdom; 4Institut de Recherches Internationales, Servier, Courbevoie, France phMRI was used to determine brain areas activated by the novel anti-depressant agomelatine at 3 doses. T2*-weighted GE images were acquired continuously before and after injection of agomelatine or vehicle in isoflurane-anaesthetized rats. A pseudoblock analysis was performed in SPM5, revealing significant areas of activation and deactivation including cortical, hippocampal and caudate regions. There was a marked effect of dose with more brain areas, more total voxels and higher Z-scores at a dose of 20mg/kg compared to either 10 or 40mg/kg. Agomelatine acts at both melatonin and serotonin receptors and both receptors are likely to be involved in these responses. Christopher James Martin1, Nicola R. Sibson1 1Radiation Oncology and Biology, University of Oxford, Oxford, Oxfordshire, United Kingdom The aim of this work was to combine pharmacological magnetic resonance imaging with electrophysiological recording of neuronal activity such that we might improve our understanding of: (1) the neural basis of neuroimaging signals; (2) the effects of neuropharmacological manipulations on neurovascular coupling and neuroimaging signals; and (3) neuroanatomical differences in the relationship between neuronal activity and neuroimaging signals. We report data from studies in which we use the serotonin (5-HT) releasing agent fenfluramine to increase endogenous 5HT levels and investigate the effects of this modulation on both baseline and stimulus-evoked fMRI signals and neuronal activity. 1228. BOLD PhMRI in the Rat on a Clinical 3T Scanner Using Cocaine Challenge Edwin Heijman1, Duncan Jack Hodkinson2, Roland van de Molengraaf3, Brian Henry4, Shane McKie5, Charles Sio1 1Philips Research Europe, Philips, Eindhoven, Netherlands; 2Imaging Science and Biomedical Engineering, The University of Manchester, Manchester, United Kingdom; 3Life Science Facilities, Philips Research, Philips, Eindhoven, Netherlands; 4Translational Medicine Research Centre, Schering-Plough, Singapore, Singapore; 5Neuroscience and Psychiatry Unit, The University of Manchester, Manchester, United Kingdom In this study we investigated the potential applications of a clinical 3T system for pharmacological MRI (phMRI) in the rat brain. Using a human 3T MRI scanner, a dynamic SE-EPI BOLD sequence was implemented to determine alterations between pre- and post-injection of 5 mg/kg cocaine in male Sprague-Dawley rats under isoflurane anesthesia. Data analysis was performed using pseudoblock analyses. Cocaine-saline subtraction across the time series, showed significant activations in cortico-limibc areas of the motor, retrosplenial, and piriform cortex, extending to subcortical areas of the antero-dorsal hippocampus. We conclude that pre-clinical phMRI studies can be performed using 3T clinical scanners. 1229. Effects of Doxorubicin on Brain Activity and Functional Connectivity in Rats Alan S. Bloom1, Peter S. LaViolette2, Christopher R. Chitambar3, William Collier1, Sally J. Durgerian4, Balaraman Kalyanaraman2, Donna M. McAllister2, Carol L. Williams1, Kathleen M. Schmainda5 1Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, United States; 2Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 3Neoplastic Diseases and Hematology, Medical College of Wisconsin, Milwaukee, WI, United States; 4Neurology, Medical College of Wisconsin, Milwaukee, WI, United States; 5Radiology and Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States The purpose of this research was to investigate chemobrain at a mechanistic level by determining the effects of doxorubicin, one of the agents commonly used for the adjuvant chemotherapy of breast cancer, on brain function using fMRI and fcMRI in a rat model. . We observed in a small group of rats treated weekly with DOX that it alters brain activation by sensory stimulation particularly in regions associated with vision and that we are able to demonstrate resting state functional connectivity MRI in the anesthetized rat and that it is decreased by DOX treatment, particularly in the visual system. Athersclerosis & Coronary MRI Hall B Monday 14:00-16:00 Raimo P. Joensuu1, Louise M A Anderson, 12, Anna E. Larsson1, Li-Ming Gan1, Malin E. Palmér1, Paul D. Hockings1 1AstraZeneca R&D Molndal, Mölndal, Sweden; 2Chalmers University of Technology, Gothenburg, Sweden The purpose of this work was to evaluate the suitability of the strong collision approximation to predict the USPIO volume fraction in atherosclerotic rabbits vessel wall from the transverse relaxation time, T2*. There was an excellent agreement (R2 = 0.98) between the theory and the measurements for volume fractions larger than 15 ppm. For lower volume fractions the theory agrees with the measurements poorly. The strong collision model may predict correctly the volume fraction from the T2* map when every voxel contains a relatively high number of magnetic particles but fails if the region contains also voxels with few or no particles. Maxim V. Terekhov1, Vasily Sen'2, Valery Golubev2, Stefan Weber3, Alexander W. Scholz4, Thomas Muenzel5, Andrei L. Kleschyov5, Laura Maria Schreiber3 1Department of Radiology, Section of Medical Physics, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany; 2Institute of Problems of Chemical Physics, Russian Academy of Sciences, Russian Federation; 3Department of Radiology, Section of Medical Physics, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany; 4Department of Anesthesiology, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany; 5II-Department of Medicine, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany Cyclic nitroxides e.g. TEMPO are stable free radicals with multiple applications in MRI. Heparin is known to have a high affinity for the vascular extracellular structures. We propose that TEMPO could be delivered to the vascular wall by means of heparin-polynitroxide (HNR) derivatives where the nitroxide is linked with the heparin macromolecule. The T1,2 measurements show that HNR complexes provide the relaxivity contrast comparable with Gd-based media. The pilot MRI experiment with ex-vivo labeling of vascular wall with HNR demonstrate high potential of functionalized polynitroxide targeted to the specific structures of the vascular wall for diagnostic and therapeutic purposes. Xubin Li1,2, Huidong Gu1, Hongqing Feng1, Xiangke Du2, Bensheng Qiu1, Xiaoming Yang1 1Image-Guided Bio-Molecular Intervention Researchers, Department of Radiology; Institute for Stem Cel, University of Washington School of Medicine, Seattle, WA, United States; 2Radiology, Peking University People's Hospital, Beijing, China The aim of this study was to explore the possibility of generating high-resolution MR images of atherosclerotic aortic walls/plaques of mice using a clinical 3.0 Tesla MR scanner. This study demonstrates that clinical 3.0T MR scanners can be used for high-resolution imaging of atherosclerotic vascular walls and lesions in mice, which is guaranteed with a specific mouse RF coil, an effective ECG-gating system, and a BB-MRI sequence. Steen Fjord Pedersen1, William P. Paaske2, Troels Thiem3, Samuel A Thrysųe, Erling Falk3, Steffen Ringgaard, Won Yong Kim4 1Dept. of Cardiology, and MR-center, Aarhus University Hospital, Skejby, Aarhus, Denmark; 2Dept. of Cardiothoracic and Vascular Surgery T, Aarhus University Hospital, Skejby; 3Dept. of Cardiology, Aarhus University Hospital, Skejby; 4dept. of Cardiology, and MR-center, Aarhus University Hospital, Skejby Inflammation seems to play a key role in destabilization of atherosclerotic plaques. Detection of Inflammatory activity within atherosclerotic plaques therefore has the potential to distinguish between vulnerable and stable plaques. Using a balloon injured porcine coronary artery, we examined whether edema as a sign of inflammation could be detected in the vessel wall by MRI using a T2-STIR (known to detect edema). After injury, the T2-STIR images showed a significant increase in vessel wall enhancement of 143% (CI95 = [39.6 - 142.5]; and areas with signal enhancement correlated well to inflammation and edema confirmed by histopathology.
1234. Coronary Artery Plaque Imaging: Comparison of Black-Blood MRI and 64-MDCT Yi He1, Zhaoqi Zhang1, Qinyi Dai1, Wei Yu1, Biao Lu1, Zhanming Fan1, Jing An2, Lixin Jin3, Guobin Li4, Wolfgang Rehwald5, Renate Jerecic3, Debiao Li6 1department of radiology, An zhen hospital, Beijing, China; 2Siemens Mindit Magnetic Resonance, Siemens Healthcare, MR Collaboration NE Asia; 3Siemens Limited China, Siemens Healthcare, MR Collaboration NE Asia; 4Siemens Mindit Magnetic Resonance Ltd; 5Siemens Healthcare USA; 6Northwestern University, Chicago USA This study was to evaluate the ability of black-blood coronary wall MRI to identify and classify coronary plaques by comparing with 64-MDCT.15 patients underwent black-blood coronary wall MRI and coronary 64-MDCT. In MRI, the plaque burden, maximal wall thickness, SNR, CNR in the coronary walls containing plaques were greater than those of the normal coronary walls.The SNR in the soft plaque was greater than those in calcified and mixed plaques. The conclusion was coronary wall MRI can identify coronary plaques, and has the potential to differentiate plaque types based on signal intensity.
Takeshi Ishimoto1, Yasuyo Taniguchi2, Tosiaki Miyati3, Momoe Kawakami4, Takayuki Ikeda5, Hisaya Kusabe5 1Division of Health Science, , Graduate school of Medical, Kanazawa University, Kanazawa, Ishikawa, Japan; 2Department of Cardiology, Hyogo Brain and Heart Center, Himeji, Hyogo, Japan; 3Division of Health Science,, Graduate school of Medical, Kanazawa University, Kanazawa, Ishikawa, Japan; 4Radiology and Clinical Laboratory, Hyogo Brain and Heart Center, Himeji , Hyogo, Japan; 5Radiology and Clinical Laboratory, Hyogo Brain and Heart Center, Himeji, Hyogo, Japan In the study, we sought to determine whether coronary vessel wall imaging using inversion recovery prepared SSFP correlate with atherosclerosis detected by 64 raw MDCT. IR-SSFP can be used to non-invasively visualize the coronary vessel wall and to detect the presence of (sub)clinical coronary atherosclerosis . HSI of IR-SSFP may be indicative of plaque inflammation and/or hemorrhage. Therefore, coronary plaque vulnerability could be predicted by cardiac MRI. Further studies are needed to define the importance of these findings in the detection and treatment of vulnerable plaques. Peng Hu1, Jonathan Chan, Jouke Smink2, Beth Goddu, Kraig V. Kissinger, Lois A. Goepfert, Thomas H. Hauser, Neil M. Rofsky3, Warren J. Manning, Reza Nezafat 1Beth Israel Deaconess Medical Center, Boston, MA, United States; 2Philips Healthcare; 3Radiology, Beth Israel Deaconess Medical Center We sought to investigate the contrast injection timing and rate for contrast-enhanced coronary artery MRI and compared the images acquired with optimized contrast timing to non-contrast T2-prep whole-heart SSFP coronary MRI at 1.5T. We studied time-resolved blood T1 after gadobenate dimeglumine (Gd-BOPTA) injection using three infusion schemes (bolus, slow infusion and hybrid). Subsequently, we evaluated an isotropic contrast-enhanced whole-heart coronary MRI method at 1.5T using an inversion-recovery SSFP sequence acquired after a bolus infusion of Gd-BOPTA. The contrast-enhanced coronary MRI increased blood SNR by 36% and increased coronary-myocardium CNR by 101%. There was no significant difference in image quality. 1237. 3D Flow-Insensitve Coronary Vessel Wall Imaging Using Phase Sensitive Inversion Recovery Jingsi Xie1, Himanshu Bhat1, Zhaoyang Fan1, Debiao Li1 1Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States Developed a 3D flow-insensitive coronary vessel wall imaging technique. Heng Ma1, Lan Ge2, Qi Yang1, Dong Xu1, Han Li1, Qing Tang1, Jiangtao Liu1, Wen Qin1, Jing An3, Lixin Jin4, Renate Jerecic4, Xiangying Du1, Kuncheng Li1, Debiao Li2 1Xuanwu Hospital, Capital Medical University, Beijing, China; 2Radiology, Northwestern University, Chicago, IL, United States; 3Siemens Mindit Magnetic Resonance Ltd, Shenzhen, China; 4Siemens Ltd, Healthcare Sector, China Fifty-one subjects underwent contrast-enhanced whole-heart coronary magnetic resonance angiography at 3.0T. All major cardiac veins, except for the vein of Marshall, could be depicted successfully. Jian Xu1,2, Daniel Kim3, Ricardo Otazo3, Sven Zuehlsdorff4, Xiaoming Bi4, Bernd Stoeckel1, Daniel Sodickson3 1Siemens Medical Solutions USA Inc., New York, NY, United States; 2PolyTechnic Institute of NYU, New York, NY, United States; 3Center for Biomedical Imaging,Department of Radiology, New York University, New York, NY, United States; 4Siemens Medical Solutions USA Inc., Chicago, NY, United States To develop a new approach for high resolution 3D whole heart coronary MRA in a single breath-hold, which offers the potential to enhance imaging efficiency and spatial resolution without apparent misregistration between external RF coil calibration scan and imaging scan. Peter Börnert1, Kay Nehrke1, Holger Eggers1, Peter Koken1 1Philips Research Europe, Hamburg, Germany Fat suppression is essential to improve contrast in MR coronary angiography (CMRA) but fat also contains helpful diagnostic information. In particular, the intra-myocardial fat represents an important diagnostic indicator that could have high prognostic value. Therefore, in this work whole heart CMRA-type imaging is proposed that delivers both, the coronary tree and the fat signal distribution at the same spatial resolution. Dixon-based chemical shift encoded spiral imaging is used allowing to separate water and fat and to benefits from the “Bo -based off-resonance correction. This concept was applied and validated in volunteers and shows that efficient CMRA and intra-myocardial fat detection is possible with large volume coverage. 1241. MR-Imaging of the Coronary Arteries of Mice in Vivo Arno Nauerth1, Erich Treiber1, Claudia Oerther1, Ulrich Flögel2 1Bruker BioSpin MRI GmbH, Ettlingen, Germany; 2Institut für Herz- und Kreislaufphysiologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany In this study the dynamic filling of the coronary arteries in mice was visualized by using a cryogenically cooled surface coil for SNR improvement and by using a self-gated method with full heart coverage which corrects for cardiac and respiratory motions. The results presents volume-targeted cine-MIPs. 1242. Analysis of Small Dilation Detection in Coronary Angiography Travis B. Smith1, Krishna S. Nayak1 1Electrical Engineering, University of Southern California, Los Angeles, CA, United States Estimation of coronary artery cross-sectional lumen area from MR images is now being used to assess the relationship between atherosclerosis and vasomotion response to endothelial-dependent stimuli. Typically, cross-sectional images of the coronary lumen acquired before and after administration of such stimuli are fit to circular templates to estimate the change in area. These studies have reported very small mean changes in lumen area. In this work, we develop a statistical framework for the detection of these subtle changes in lumen area using two images. We use this framework to relate detection performance to SNR requirements and minimum detectable dilation. 1243. Analysis of Coronary Vein Motion: Implications for MR Coronary Vein Venography Pierre John Watson1, Jonathan D. Suever2, John N. Oshinski1 1Radiology, Emory University, Atlanta, GA, United States; 2Biomedical Engineering, Georgia Institute of Technology The periods of low motion of the coronary veins during the cardiac cycle were quantified using 3D magnetic resonance coronary venograms (cMRV) in 16 patients with ischemic heart disease. The temporal location and duration of these periods were determined using the frame-to-frame displacement method on the coronary sinus. The patients were classified as either systolic or diastolic dominant based on the duration of the periods. The majority of patients were systolic dominant although about a third of the patients either had a very short diastolic period or lacked it completely. Yuki Ohmoto1, Rieko Ishimura2, Takashi Yoshida3, Miho Yabuyamada3, Junji Takahashi3, Shigehide Kuhara4, Sachiko Isono4, Ayako Ninomiya4, Mitsue Miyazaki4, Hiroyuki Tsuji1, Yasuji Arase1 1Health Management Center, Toranomon Hospital, Minato-ku, Tokyo, Japan; 2Cardiovascular Center, Toranomon Hospital; 3Radiology, Toranomon Hospital; 4MRI systems Division, Toshiba Medical Systems Corporation Whole-Heart Magnetic Resonance Coronary Angiography (WH MRCA) is a very useful tool for screening for coronary artery disease and usually performed during free breathing with real time motion correction (RMC). We have developed a Motion Correction Coefficient Pre-Analysis Method to obtain an appropriate RMC coefficient before the WH MRCA scan and performed the feasibility study of this method by evaluating the relation between the coefficient of RMC and the image quality for health screening cases retrospectively. The results showed that this method is expected to be very useful in the clinical application of WH MRCA. Ayako Ninomiya1, Shigehide Kuhara1, Tomohisa Okada2, Tetsuo Sato3, Kotaro Minato3, Shoutaro Kanao2, Kaori Togashi2 1MRI Systems Division, Toshiba Medical Systems Corporation, Otawara-shi, Tochigi, Japan; 2Kyoto University Hospital, Kyoto, Japan; 3Nara Institute of Science and Technology, Nara, Japan We have developed the Global-to-Local Tandem Method to detect the coronary stationary period for WH MRCA, in which the coronary stationary period is roughly analyzed by the global method and then more precisely analyzed by the local method. We have also conducted clinical feasibility studies. Results suggest that The Global-to-Local Tandem Method can robustly detect the coronary artery stationary period in WH MRCA (Whole Heart Magnetic Resonance Coronary Angiography). It is therefore concluded that this method should prove to be very useful for clinical WH MRCA examinations. 1246. Retrospective Motion-Adapted Smart Averaging for Free-Breathing Cardiac MRI Alan Christopher O'Connor1,2, Mehdi Hedjazi Moghari1, Peng Hu1, Dana C. Peters1, Warren J. Manning1, Reza Nezafat1, Roger Ware Brockett2 1Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 2SEAS, Harvard University, Cambridge, MA, United States Navigator gating is an accepted method for reducing the effect of respiratory motion in cardiac MRI; however, it does not exploit the fact that different spatial frequencies are more or less sensitive to the respiratory motion. We present a smart motion-adapted averaging method that retrospectively corrects for respiratory motion by combining data from k-space lines of multiple acquisitions using weights determined by the navigator signal. 1247. CoSMo: Compressed Sensing Motion Correction for Coronary MRI Mehdi Hedjazi Moghari *1, Mehmet Akēakaya *,12, Alan O'Connor, 12, Peng Hu1, Vahid Tarokh2, Warren J. Manning1, Reza Nezafat1 1Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 2Harvard University, Cambridge, MA, United States We examine the feasibility of using compressed sensing to reduce artifacts due to respiratory motion. Respiratory motion causes image artifacts and ghosting in cardiac imaging. Respiratory navigators are one of the methods used to mitigate these artifacts for free-breathing scans, where k-space lines falling outside a pre-defined gating window are reacquired until the whole k-space is filled. In this study, we introduce CoSMo, a compressed sensing-based method for reconstructing images without having to reacquire k-space lines rejected by the navigator. 1248. New Approach for Patient-Specific Estimation of Cardiac Motion Due to Respiration Florencio Rusty Baldomaro Punzalan1, Tetsuo Sato1, Tomohisa Okada2, Shigehide Kuhara3, Kaori Togashi2, Kotaro Minato1 1Graduate School of Information Science, Nara Institute of Science and Technology, Ikoma, Nara, Japan; 2Department of Diagnostic Radiology, Kyoto University Hospital, Kyoto, Japan; 3MRI Systems Division, Toshiba Medical Systems, Tochigi, Japan Respiratory motion compensation for cardiac imaging requires a patient-specific knowledge of the hearts motion. In this study, the respiratory-induced motion of the upper and lower part of the heart was investigated during free-breathing. We observed significant inter-subject variation of upper and lower heart motion tracking factors. The tracking factor for the lower part is larger than the upper part for all subjects. This will help motion models account for the different displacements and velocities of coronary vessels located in the atrio-ventricular groove (RCA and LCX) and the apex (LAD) which are located in the lower and upper heart, respectively. Gerrit Schönwald1, Gregor Schaefers2, Georg Haltern3, Brigitte Kipfmüller4 1University Witten/Herdecke, Gelsenkirchen, NRW, Germany; 2MR:comp GmbH, Gelsenkirchen, Germany; 3HELIOS Heart Center , Wuppertal, Germany; 4University of applied Science Gelsenkirchen, Germany Purpose Development of a standardized procedure to evaluate which factors need to be optimized for quantification of in-stent stenosis by analysis of lumenvisibility in a static MRI model of coronary in-stent stenosis. Methods Stents were placed into tubes and equipped with artificial restenosis made of a pre-investigated material. The tubes were placed in a phantom. A 1.5 and a 3 Tesla MR-system were used. Results Quantification of in-stent stenosis was limited in stainless steel stents and cobalt-chromium stents by artifacts. Tantalum stent showed a lower rate of artifacts. Conclusion Image quality was strongly depended from stent material and stent design. Vessel Wall Imaging (Non-Coronary) Hall B Tuesday 13:30-15:30 Andrew J. Patterson1, Victoria E. Young1, Martin J. Graves1, Jonathan H. Gillard1 1Radiology, University of Cambridge, Cambridge, England, United Kingdom Double inversion recovery prepared, fast spin echo, black blood imaging has been widely used for assessing carotid plaque tissue composition. The protocol is used to obtain T1-, T2- and PD-weighted contrast. This study compares the between subject and within subject differences in the signal-to-noise ratio and the contrast-to-noise ratio from single- and multi-slice acquisition using both a gated and ungated trigger. Hao Shen1, Guang Cao2, QingJun Wang3 1Applied Science Laboratory, GE Healthcare, Beijing, China; 2Applied Science Laboratory, GE Healthcare, Hong Kong, China; 3Department of Radiology, Chinese PLA General Hospital, Beijing, China Black blood is important in carotid plaque characterization. In this study, we developed a black blood spoiled gradient recalled sequence by using spacial labeling with multiple inversion pulses preparation. Seong-Eun Kim1,2, Scott McNally2, Laura K. Findeiss2, Jordan Hulet3, John Roberts1,2, Eun-Kee Jeong1,2, Dennis L. Parker1,2, Gerald S. Treiman4,5 1UCAIR, University of Utah, Salt Lake City, UT, United States; 2Department of Radiology, University of Utah, Salt Lake City, UT, United States; 3Department of Biomedical Informatics, University of Utah; 4Department of Surgery, University of Utah, Salt Lake City, UT, United States; 5Veterans Affair, VASLCHCS, Salt Lake City, UT, United States 2D TSE with DIR is the current technique for identification of the component of carotid plaque. This approach is limited by inadequate spatial resolution that is often necessary to identify small areas of plaque components. 3D imaging offers the potential to improve spatial resolution. We have utilized 3D TSE with non-selective 180o RF and have implemented an inner volume imaging(IVI) technique. The non-selective 180o RF allow significantly more echoes to be acquired resulting in more efficient 3D scan. IVI technique reduces the field of view in the phase encoding direction and requires fewer phase encoding line, further reducing scan time. 1253. Intravascular 3.0T MR Imaging: A Feasibility Study in Swine Yanfeng Meng1,2, Feng Zhang1, Huidong Gu1, Jinnan Wang3, Chun Yuan1, Zhaoqi Zhang2, Bensheng Qiu1, Xiaoming Yang1 1Radiology, University of Washington, Seattle, WA, United States; 2Radiology, Beijing Anzhen Hospital, Beijing, China; 3Clinical Sites Research Program, Philips Research North America, Briarcliff Manor, NY, United States This study was to validate the feasibility of generating intravascular 3T MRI of deep-seated arteries of near-human-sized swine by using a 3T-MR compatible MR-imaging guidewire (MRIG). For in vitro testing, we compared SNRs generated by a 0.032-inch MRIG and surface coils. For in vivo validation, we performed intravenous MRI of the parallel-run iliofemoral arteries with this MRIG. The SNR by the MRIG was higher than surface coils, and the iliofemoral arterial walls were clearly delineated with the MRIG at a higher SNR than surface coils. This study establishes the groundwork for further intravascular 3T MRI of deep-seated arteries in humans. Ronald van 't Klooster1, Andrew J. Patterson2, Victoria E. Young2, Jonathan H. Gillard2, Johan H.C. Reiber1, Rob J. van der Geest1 1Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands; 2University Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom Extensive MR vessel wall imaging protocols are used to identify unstable plaques, which play an important role in the progression of atherosclerosis. Comparison was made between automatic plaque detection, by a supervised classification system, and histology assisted manual segmentation. Experiments show that the automatic detection of unstable plaque is in good agreement with the manual segmentation. Moreover, the STIR and DWI sequences show an improvement over the T2w and PDw sequences. Automatic detection of soft plaque may be feasible by using a limited number of MR sequences, saving both MRI system and image analysis time. Jinnan Wang1, Marina S. Ferguson2, Niranjan Balu2, Chun Yuan2, Peter Boernert3 1Clinical Sites Research Program, Philips Research North America, Seattle, WA, United States; 2University of Washington; 3Philips Research Europe Ultra-short TE (UTE) images can provide positive contrast for short T2 species when combined with imaging techniques like dual-echo subtraction or magnetization preparation. Although the calcified regions identified on UTE images were demonstrated to agree with CT images, its accuracy has not been validated against histology. This study is aimed at comparing the accuracy of UTE calcification detection in human carotid plaques against regular turbo spin echo MR images, as well as validating it against histology. Li Dong1, William Sean Kerwin1, Chun Yuan1, Xue-Qiao Zhao1 1University of Washington, Seattle, WA, United States We hypothesized that lipid-lowering therapy leads to biological changes in arterial walls that result in altered MRI contrast, even in the absence of a developed necrotic core. In a carotid MRI study of atorvastatin, 42 subjects exhibited no necrotic core. Within this group, no measurable change in wall thickness occurred over 3 years, but a highly significant (p<0.001) change in T2-weighted versus T1-weighted signal intensity was observed. Therefore, signal changes in the vessel wall may be more sensitive than plaque burden for measuring treatment effects in early lesions of atherosclerosis. 1257. MR Elastography of the In Vivo Abdominal Aorta: Feasibility Study Arunark Kolipaka1, David A. Woodrum1, Krzysztof R. Gorny1, Oscar I. Garcia Medina1, Anthony J. Romano2, Richard L. Ehman1 1Radiology, Mayo Clinic, Rochester, MN, United States; 2Acoustics Division, Naval Research Laboratory, Washington DC, United States To date there is no noninvasive method to reliably estimate the stiffness of the abdominal aorta. We are investigating MR elastography to estimate the stiffness of in vivo abdominal aorta in normals and controlled hypertensive volunteer. Our preliminary results suggest that discernible waves are observed in the abdominal aorta, and controlled hypertensive volunteer has shown higher stiffness measurement when compared to normal volunteers. Therefore, MRE technique is feasible and can be used to examine the stiffness of the abdominal aorta. Glenda Sibylle van Bochove1, Martijn L. Chatrou1, Leonie E. Paulis1, Holger Grüll1,2, Gustav J. Strijkers1, Klaas Nicolay1 1Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 2Bio-Molecular Engineering, Philips Research Europe, Eindhoven, Netherlands The purpose of this study was to image VCAM-1 expression in carotid artery lesions of apoE-/- mice, to compare the efficacy of a lipid-based paramagnetic and a lipid-based superparamagnetic contrast agent, and to relate contrast changes to plaque location. Paramagnetic liposomes and superparamagnetic micellar iron oxides targeted to VCAM-1 were prepared. Both contrast agents showed strong and specific accumulation in VCAM-1 over-expressing cells in vitro. In vivo targeting to mouse carotid artery atherosclerotic plaques was demonstrated. Contrast changes were most pronounced in the plaque shoulders, which are known to be most active in inflammatory cell recruitment. Xihai Zhao1, Huilin Zhao2, Ye Cao2, Jinnan Wang3, Niranjan Balu1, Jianrong Xu2, Chuan Yuan1 1Radiology, University of Washington, Seattle, WA, United States; 2Radiology, Shanghai Renji hospital, Shanghai Jiaotong University, Shanghai, China; 33. Philips Research North America, Briarcliff Manor, NY, United States Atherosclerosis is a systemic disease frequently involving multiple vascular territories, such as carotid artery and thoracic aorta, which are related to cerebrovascular events. Thus, atherosclerotic disease in one vascular bed may be an indicator for the other vasculatures. This study sought to determine the association between carotid artery and thoracic aorta atherosclerosis using MR black-blood vessel wall imaging in 26 symptomatic patients. We found that carotid artery plaque burden, particularly on left side, was significantly associated with that of descending aorta. Our findings suggest that atherosclerotic disease in carotid artery may be an indicator of thoracic atheroma, or vice versa. 1260. Accelerating 3D Molecular MR Imaging Using Compressed Sensing Claudia Prieto1, Marcelo Andia1, Tobias Schaeffter1, Rene M. Botnar1 1Division of Imaging Sciences, King's College London, London, United Kingdom Accelerated Molecular MR-imaging using Compressed Sensing (CS) is demonstrated for preclinical applications. The sparsity requirement of CS is satisfied in most molecular MR-images, due to the high localized T1-contrast enhancement produced by target-specific contrast agents. Good overall image quality was achieved with acceleration factors up to 4 in 3D preclinical studies of venous thromboembolism and aortic vessel wall. CS is especially useful for small animal studies (requiring high spatial resolution and thus suffering from prolonged scan times), whereas other acceleration techniques such as parallel imaging often cannot be applied due to the limited availability of multi channel small animal coils. 1261. Anti-Angiotensin Drug Evaluation in ApoE-/- Mice by USPIO-Enhanced MRI at 7T Olivia Monica Sigovan1, Amine Bessaad1, Elena Kaye2, Eric Lancelot3, Claire Corot3, Nicolas Provost4, Zouher Majd4, Magali Breisse4, Emmanuelle Canet-Soulas1 1CREATIS-LRMN Laboratory, Lyon1 University, Lyon, France; 2Radiology, Stanford University, United States; 3Guerbet Group, Paris, France; 4Genfit, Lille, France Irbesartan (SR 47436) is an orally active nonpeptide Angiotensin II type 1 (AT1) receptor antagonist. We report here an USPIO-enhanced MRI follow-up study performed on apolipoprotein (apo) E-deficient mice with the goal of following Irbesartans therapeutic effect on the development and progression of atherosclerotic lesions. Irbesartan lead to a marked reduction in the plaque formation. Post USPIO T2* values measured in the vessel wall showed significant decrease compared to baseline values, however no differences were found between treated and not treated groups. The obtained information (from the ascending aorta) may not be representative of the general effect of the drug. 1262. DCE-MRI for the Evaluation of Atherosclerosis in Patients with Exposure to Particulate Matter Venkatesh Mani1, Simonette T. Sawit2, Claudia Calcagno1, Cynara Maceda2, Colin Moncrieff1, Zahi Adel Fayad1, Jacqueline Moline3, MaryAnn McLaughlin2 1Radiology, Mount Sinai School of Medicine, New York, NY, United States; 2Cardiology, Mount Sinai School of Medicine, New York, NY, United States; 3Preventive Medicine, Mount Sinai School of Medicine, New York, NY, United States Exposure to particulate matter (PM) has been associated with adverse health effects leading to increased morbidity and mortality. Dynamic contrast enhanced (DCE) MRI and peripheral arterial tonometry (PAT) may potentially be used to evaluate differences in atherosclerosis in patients with high and low PM exposure. There was correlation between DCE-MRI measures and endothelial function measured by PAT. Despite NO significant differences between groups in patient characteristics, and vessel wall morphometrics, high exposure group had significantly lower DCE MRI measures. We conclude that DCE-MRI may be used to evaluate differences in atherosclerosis due to different levels of PM exposure. Andrew James Patterson1, Tjun Y. Tang1, Martin J. Graves1, Simon P. S. Howarth1, Jonathan H. Gillard1 1Radiology, University of Cambridge, Cambridge, England, United Kingdom Previous studies have reported Ultra-Small Super-Paramagnetic Iron Oxide (USPIO) detected inflammation in carotid atherosclerotic disease using a semi-quantitative analysis technique that involves measuring changes in signal intensity relative to adjacent muscle tissue. In this study an alternative method to detect and quantify changes over-time is presented. The methodology involved making direct quantitative T2* measurements within the atherosclerotic plaque pre- and post- infusion. In a double blinded randomised control trail this study measured a significant difference (p<0.001) with respect to time in USPIO-detected inflammation between patients receiving low-dose and high-dose statin therapy. Robert Kwee1, Robert van Oostenbrugge, Martin Prins, Jos van Engelshoven, Joachim Wildberger, Werner Mess, Eline Kooi 1Maastricht University Medical Center, Maastricht, Limburg, Netherlands We found that TIA/stroke patients with moderate carotid stenosis have a higher prevalence of complicated plaques at MRI compared to TIA/stroke patients with mild stenosis. Increasing age is positively associated with the presence of IPH, while the use of statins is negatively associated with complicated plaque features. Other major cardiovascular risk factors were not associated with plaque composition, suggesting that assessment of plaque composition provides independent information, which might be used to improve risk-stratification for stroke. Huijun Chen1, Jinhui Shen1, William S. Kerwin1 1Department of Radiology, University of Washington, Seattle, WA, United States DCE-MRI has been shown to be sensitive to inflammatory content within plaque. Previous bright-blood technique is not compatible with early lesions due to the enhancement contamination from lumen. Recently, the area under enhancement curve (AUC) has been found to be associated with neovessels in early atherosclerosis by black-blood imaging. In this study, we demonstrated the potential for kinetic modeling of black blood DCE-MRI of atherosclerotic plaque using a reference region approach to the Patlak model. Using an animal model of early atherosclerosis, both kinetic parameters exhibited better reproducibility and stronger correlation with inflammatory bio-markers than the AUC ratio. 1266. MRI Detects Oxidative Stress Induced by Methaemoglobin General Leung1, Alan R. Moody1 1Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada Carotid plaque haemorrhage detected by magnetic resonance imaging appears to be prognostic regarding plaque progression and patient outcome. It is accepted that oxidative modification of low density lipoprotein (LDL) first causes then drives plaque development. We demonstrate in vitro that the signal hyperintensity caused by ferric haemoglobin, a major portion of intraplaque haemorrhage detected by MRI, is associated with an environment that is a potent oxidiser of LDL. Keigo Kawaji1,2, Thanh D. Nguyen2, Beatriu Reig2, Pascal Spincemaille2, Martin R. Prince2, Yi Wang1,2 1Biomedical Engineering, Cornell University, Ithaca, NY, United States; 2Radiology, Weill Cornell Medical College, New York, NY, United States This work compared the performance of four black-blood magnetization preparation techniques [double inversion recovery (DIR), spatial presaturation of upstream blood (SpSat), motion-sensitizing magnetization preparation (MSprep), and T2prep inversion recovery (T2prep-IR)] in suppressing blood signal in a 3D balanced steady-state free precession MRA of the lower extremity. In 11 volunteers, the proximal popliteal was imaged at 1.5-Tesla with the four magnetization preparation techniques. Both MSprep and T2prep-IR provided global blood suppression and vessel wall visualization across a 3D volume, while upstream blood nulled by DIR and SpSat did not travel across the entire 3D volume. 1268. Ruptured Carotid Plaques as a Feature in Patients with Unstable Angina Pectoris Jianming Cai1, Qingjun Wang1, Yong Wang1, Youquan Cai1, Lin Ma1, Dongxiang Xu2, Chun Yuan2 1Radiology, Chinese PLA General Hospital, Beijing, China; 2Radiology, University of Washington, Seattle, WA, United States By using multi-contrast high-resolution MRI, we studied prospectively whether carotid plaque characteristics can predict unstable angina pectoris (UAP). In the present study, each subject with stenosis >50% in one or more major coronary arteries was performed a carotid MRI examination on a 3.0-T MRI scanner. Our findings show that the presence of fibrous cap rupture was the strongest independent predictor of UAP. With a multi-contrast high-resolution MRI, the ruptured carotid plaques may be a surrogate marker for identifying patients at high risk of UAP and may contribute to a better risk stratification of patients with coronary artery disease. 1269. Intracranial Vessel Wall Imaging at 7 Tesla Jaco J.M. Zwanenburg1, Anja G. van der Kolk1, Jeroen Hendrikse1, Peter R. Luijten1 1Radiology, University Medical Center Utrecht, Utrecht, Netherlands A volumetric (3D) turbo spin echo (TSE) sequence for intracranial vessel wall imaging at 7 Tesla is presented. Images show the vessel walls of the circle of Willis, and of the ophtalmica. Seong-Eun Kim1,2, Scott McNally2, Laura K. Findeiss2, Jordan Hulet3, John Roberts1,2, Eun-Kee Jeong1,2, Dennis L. Parker1,2, Gerald S. Treiman4,5 1UCAIR, University of Utah, Salt Lake City, UT, United States; 2Department of Radiology, University of Utah, Salt Lake City, UT, United States; 3Department of Biomedical Informatics, University of Utah; 4Department of Surgery, University of Utah, Salt Lake City, UT, United States; 5Veterans Affair, VASLCHCS, Salt Lake City, UT, United States Atherosclerotic plaques are composed of varying degrees of lipid, necrotic tissue, loose connective tissue, hemorrhage, and calcification. The extent of lipid accumulation and the presence of intramural hemorrhage have been found to be associated with the degree of plaque vulnerability and risk of plaque rupture. Recent ex vivo studies of carotid plaques found that DWI could detect lipids and hemorrhage with greater sensitivity than other MRI. This study reports the ADC values of lipid, hemorrhage and overall wall composition as measured with in-vivo DWI, with histology used as the basis for comparison 1271. High Resolution 3D Carotid Plaque Perfusion Mapping and Its Association with T2 Hyperintensity Michael Jerosch-Herold1, YiuCho Chung2, Ravi Teja Seethamraju3, Otavio R. Coelho-Filho4, Marcelo Fernando Di Carli, Peter Libby, Raymond Y. Kwong 1Radiology, Brigham & Women's Hospital, Boston, MA, United States; 2MRI, Siemens Medical Systems, Columbus, OH, United States; 3Siemens Medical Systems, Boston, MA, United States; 4Brigham & Women's Hospital, United States The transfer rate (Ktrans) of gadolinium contrast into the extracellular space is a validated marker of carotid plaque neo-vascularization and inflammation. T2-weighted imaging is a complementary marker of inflammation in vessel wall and plaque. The association between Ktrans and increased SI on T2 images of carotid plaque was investigated in this study by high resolution, 3D dynamic T1w gradient echo imaging, and a 3D T2w TSE method (T2-SPACE). Ktrans and T2-signal hyper-enhancement were found to be strongly associated markers of neo-vascularization and inflammation, respectively. Ahmed Klink1, Joeri Heynens2, Beatriz Herranz3, Hendrik M. Sanders2, Gustav J. Strijkers2, Klaas Nicolay2, Maarten Merkx, Ziad Mallat4, Willem J.M. Mulder1, Zahi A. Fayad1 1Translational and Molecular Imaging Institute, Mount Sinai School of Medicine, New York, NY, United States; 2Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 3Vascular Imaging and Atherothrombosis, CNIC, Madrid, Spain; 4Paris Cardiovascular Research Center, INSERM, U689, Paris, France The in vivo characterization of a novel mouse model of abdominal aortic aneurysm (AAA) was achieved with both multi-contrast MRI (PDW, T2W, T1W, TOF) and collagen-targeted MR molecular imaging. The latter was performed with fluorescent/paramagnetic micelles conjugated to the collagen-specific protein CNA35. This allowed the imaging of the collagen turnover believed to be key in AAA progression and rupture. We established that these MRI tools were very valuable for the longitudinal investigation of AAA progression in this mouse model of AAA. Raphael Duivenvoorden1, Adriaan G. Holleboom1, Eric de Groot1, Dirkjan F. Enklaar1, Johan S. Laméris2, John J.P. Kastelein1, Erik S.G. Stroes1, Aart J. Nederveen2 1Vascular Medicine, Academic Medical Center, Amsterdam, NH, Netherlands; 2Radiology, Academic Medical Center, Amsterdam, NH, Netherlands We developed a carotid MRS protocol to non-invasively test the relation between the lipid to water ratio at the location of the carotid artery wall and carotid artery wall dimensions. We found that the lipid:water ratio correlated with the carotid artery wall dimensions, independent of serum lipid levels. Further research is needed to resolve whether MRS is a useful tool to assess the efficacy of lipid altering pharmacotherapy in the treatment of advanced atherosclerotic lesions. Li Dong1, Jinnan Wang2, Vasily Yarnykh1, Hunter Underhill1, Moni Neradilek3, Thomas Hatsukami1, Chun Yuan1 1University of Washington, Seattle, WA, United States; 2Philips Research North America; 3The Mountain-Whisper-Light Statistics Previous studies found that a turbo spin-echo based motion-sensitized driven-equilibrium (MSDE) sequence, provides more efficient residual flow signal suppression than the widely used multislice double inversion recovery (mDIR). However, whether this improved flow-suppression can improve reproducibility in atherosclerotic burden measurement is unknown. Bilateral carotid arteries (n=36) from 18 asymptomatic subjects underwent two carotid MRI examinations within 12 days. Compared to mDIR, the MSDE technique had a significantly reduced inter-scan reproducibility for lumen and wall area. For future clinical trials using carotid MRI, improved flow suppression techniques is recommended to monitor progression or regression of atherosclerosis plaque burden. 1275. Femoral Artery Vessel Wall Imaging Using Contrast-Enhanced, Susceptibility Weighted Imaging Qi Liu1, Zhaoyang Fan1, Qi Yang2, E Mark Haacke3, Debiao Li1 1Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States; 2Xuanwu Hospital, Beijing, China; 3Department of Biomedical Engineering, Wayne State University, Detroit, MI, United States By using a gradient-echo sequence with a relatively long echo time with flow compensation, together with proper post processing to preserve tissue susceptibility property while removing unwanted phase aliasing, arterial wall delineation was achieved in SWI phase images. To further enhance the lumen-wall contrast in phase images, we hypothesized that by injecting contrast agent which is known to alter blood susceptibility, more pronounced lumen-wall contrast could be obtained. Our contrast-enhanced SWI study on volunteers has confirmed the above hypothesis and observed substantial increase in lumen-wall phase contrast. 1276. Zoom Imaging for Cardiovascular Risk Assessment Tarique Hussain1, Rachel Clough1, Gerald Greil1, Rene Botnar1 1Division of Imaging Sciences, King's College London, London, United Kingdom In this study we applied the restricted field-of-view (FOV) zoom imaging technique for the reduction of scan time in diagnostic turbo-spin-echo (TSE) black blood aortic vessel wall imaging. Images were compared to a full FOV vessel wall acquisition and image quality was assessed. 1277. Serial Contrast-Enhanced Vessel Wall MRI in a Model of Plaque Neovascularization Stephanie Elaine Chiu1, General Leung1, James Q. Zhan2, Alan R. Moody, 12 1Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 2Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada This study introduces a measure extracted from gadofosveset-enhanced MR images of advanced rabbit atherosclerotic plaques for the study of plaque neovascularization. Animals were scanned 1 week before, 5 weeks after, and 10 weeks after endothelial denudation of the abdominal aorta. Vessel wall enhancement area measured from post-contrast MR images obtained prior to sacrifice was strongly associated with histologically-measured microvessel count, intimal area, and macrophage area. Vessel wall enhancement area also monitored plaque development in the same group of animals over time. This MR measure is suitable for the longitudinal study of changes in plaque neovascularization and inflammation. 1278. Magnetic Resonance Imaging of Inflammation in Abdominal Aortic Aneurysms Using USPIO Jennifer Margaret Jane Richards1, Scott I. Semple2, Calum Gray2, William Wallace3, Roderick TA Chalmers4, Olivier James Garden5, Graham McKillop6, David E. Newby1 1Centre of Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom; 2Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, United Kingdom; 3Department of Pathology, NHS Lothian, Edinburgh, United Kingdom; 4Vascular Surgical Service, NHS Lothian, Edinburgh, United Kingdom; 5Clinical and Surgical Sciences (Surgery), University of Edinburgh, Edinburgh, United Kingdom; 6Department of Radiology, NHS Lothian, Edinburgh, United Kingdom The ability to evaluate the biological processes affecting the vessel wall in abdominal aortic aneurysms (AAA) would be beneficial in addition to vessel diameter when evaluating the risk of aneurysm rupture. This is a clinical study (n=9) of the use of Magnetic Resonance Imaging and ultrasmall superparamagnetic particles of iron oxide (USPIO, Sinerem, Guerbet) to detect focal areas of inflammation in the wall of AAA. A reduction in T2* value was observed on T2* weighted imaging before and 24hrs after intravenous administration of 2.6mg/kg Sinerem. Histological examination of operative tissue samples confirmed the presence of iron in the aortic wall. Claudia Calcagno1, Venkatesh Mani1, Sarayu Ramachandran1, Silvia Aguiar1, John Postley2, Zahi A. Fayad1 1Radiology, Mount Sinai School of Medicine, New York, NY, United States; 2Columbia University - College of Physicians and Surgeons Dynamic contrast enhanced (DCE) MRI can quantify plaque inflammation in atherosclerosis, however its reproducibility is still unknown. We present a preliminary study of the inter-scan reproducibility of the area under the curve (AUC) of contrast agent uptake calculated from DCE-MRI acquisitions in patients with carotid atherosclerosis. We show excellent reproducibility of plaque AUC relative to ipsi-lateral sternocleidomastoideal muscle AUC (ICC respectively 0.972 and 0.755, p<0.05). This preliminary study show encouraging results and suggests that DCE-MRI could be a useful tool for the clinical evaluation of human atherosclerosis and/or in longitudinal clinical drug trials.
Jens T. Rosenberg1,2, Sara Campbell3, Ihssan Masad, 12, Bahram H. Arjmandi3, Samuel Colles Grant, 12 1CIMAR, The National High Magnetic Field Laboratory, Tallahassee, FL, United States; 2Chemical and Biomedical Engineering, The Florida State University, Tallahassee, FL, United States; 3Nutrition, Food and Exercise Sciences, The Florida State University, Tallahassee, FL, United States Ovariectomized (ovx) hamsters provide a model of postmenopausal atherosclerosis to investigate plaque formation in cerebral and systemic vasculature. The anti-atherogenic effects of flaxseed were studied by measuring the diameter of vessels using high resolution images acquired at high field (21.1 T). The animals were imaged at three time points: baseline, 4 months and 8 months. Atherosclerotic plaque formations were compared between sham, ovx, and ovx-flaxseed treated animals. No occlusions could be seen in cerebral arteries while differences were identified in the carotids and system circulation. Haiying Tang1, Sherif Fahmy2, Dan Zhou1, Tony Paiva1, Todd Parrish2, Jens H. Jensen3 1Merck Research Laboratories, Rahway, NJ, United States; 2Northwestern University, Chicago, IL, United States; 3New York University School of Medicine, New York, NY, United States In this study, we present ex vivo MRI assessment of USPIO uptake in aortic plaque in a mouse model of atherosclerosis at 11.7T. The purpose is to evaluate quantitative imaging methods for characterizing USPIO uptake in atherosclerotic plaque. Polymer solution phantoms, cell phantoms, and ex vivo studies were developed to help understand how different signal features are affected by the contrast agent for a variety of pulse sequences. Positive contrast techniques and susceptibility related imaging methods were compared. The goal is to determine which MRI metrics best reflect the contrast agent uptake for the purpose of quantification in living tissues. Myocardial Viability: Human Studies Hall B Wednesday 13:30-15:30 Sarah Anne Peel1, Christian Jansen1, Geraint Morton1, Simon Duckett1, Tobias Schaeffter1, René M. Botnar1 1Division of Imaging Sciences, King's College London, London, United Kingdom MRI late gadolinium enhancement using the inversion-recovery sequence is the current gold standard for the assessment of myocardial viability. Although it achieves high contrast between infarct and normal myocardium, there is often poor infarct-to-blood contrast. We sought to improve infarct-to-blood contrast using a novel non-selective double inversion technique that provides flow-independent signal suppression over a wide user-defined T1-range. Simulations and phantom studies demonstrate excellent tissue suppression over a wide T1-range. Preliminary patient data show an improvement in infarct-to-blood CNR. This technique facilitates detection of sub-endocardial defects and has potential for more accurate quantification of infarct size and transmurality. Venkat Ramanan1, Labonny Biswas1, Jay Stephen Detsky1, Rhonda Walcarius1, Gideon A. Paul1, Alexander J. Dick1, Graham A. Wright1 1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada Free-breathing, Ungated Realtime imaging using inversion recovery cartesian SSFP has been proposed to assess myocardial function and viability. However since these techniques suffer from poor temporal resolution, we have designed Realtime IR-Spiral-SSFP to improve it. Several waveforms were designed and tested resulting in different spatial and temporal resolutions. We scanned a few patients with a spiral waveform of 88ms temporal resolution and 3mm spatial resolution. Preliminary results show that this is a viable imaging approach and there is scope for further improvement to improve the tradeoffs between spatial vs temporal resolution. Benjamin R. Knowles1, Claudia Prieto1, Reza Razavi1, Tobias Schaeffter1 1Imaging Sciences, Kings College London, London, United Kingdom Current late gadolinium enhancement (LGE) techniques for the visualisation of RF ablation lesions do not reach sufficient resolution to determine if ablation lesions are transmural, We have formed a strategy to assess ablation lesion transmurality using the combination of high resolution LGE and atrial wall imaging. Both MR scans use a spiral k-space trajectory as this trajectory is a highly efficient sampling scheme. Off-resonance effects are corrected for. High-resolution LGE images are compared to the lower resolution Cartesian LGE currently in use. Thickness measurements of the atrial wall and of the enhancing areas are conducted in order to assess transmurality. Ganesh Adluru1, Sathya Vijayakumar1, Nathan Burgon2, Eugene Kholmovski1, Nassir Marrouche2, Edward DiBella1 1Radiology, University of Utah, Salt Lake City, UT, United States; 2Cardiology, University of Utah, Salt Lake City, UT, United States Atrial fibrillation currently affects over 7 million people in the U.S. and Europe. Late Gadolinium Enhancement (LGE) imaging offers a means to assess ablation of the left atrium and the pulmonary vein ostia. Here we propose to reduce the scan time and improve the image quality over a standard 3D Cartesian acquisition (with respiratory and ECG gating) by (i) acquiring data using a stack of stars scheme and (ii) using compressed sensing reconstruction methods. Results from simulated phantom and patient data show the feasibility of the method to obtain better image quality that may improve clinical utility of LGE imaging. 1286. Late Gadolinium Enhancement Can Visualize the Periinfarct Zone in Acute Myocardial Infarction Yoshiaki Morita1, Naoaki Yamada2, Teruo Noguchi3, Hiromi Hashimura2, Tetsuro Nakazawa2, Atsushi Kono2, Suzu Kanzaki2, Tetsuya Fukuda2, Masahiro Higashi2, Hiroaki Naito2 1Department of Radiology , National Cardiovascular Center , Suita, Osaka , Japan; 2Department of Radiology, National Cardiovascular Center, Suita, Osaka, Japan; 3Division of Cardiology, National Cardiovascular Center, Suita, Osaka, Japan Previous studies suggested that the periinfarct zone in acute myocardial infarction may provide the important prognostic information and serve as a therapeutic target. It is widely known that the hyperintense area in T2-weighted imaging closely matched the periinfarct zone. However, T2-weighted image is sometimes degraded by motion artifact and arrhythmia. In this study, we demonstrate that the early phase in late gadolinium enhancement (at the time of 2 minutes after gadolinium administration) can clearly visualize the periinfarct zone similar to or better than T2 map and offer robust diagnostic image quality compared to T2-weighted image. 1287. Fast Quantitative Measurement of T1 in Cardiac Delay Enhanced Studies Matteo Milanesi1, Luca Marinelli2, Christopher J. Hardy2, Vincenzo Positano1, Piergiorgio Masci1, Andrea Barison1, Maria F. Santarelli3, Luigi Landini4, Massimo Lombardi1, Thomas K. Foo2 1"G. Monasterio" Foundation, Pisa, Italy; 2Global Research Center, General Electric, Niskayuna, NY, United States; 3Institute of Clinical Physiology, National Research Council, Pisa, Italy; 4Department of Information Engineering, University of Pisa, Pisa, Italy In this work a Cine Inversion Recovery pulse sequence is presented to quantify T1 values in myocardial delay enhancement studies. FastSPGR with low flip angle is used to sample the exponential spin relaxation during the first heart beat following an adiabatic inversion pulse. The subsequent heart beat is left to allow full T1 recovery. Four patients with suspicion of heart diseases were enrolled in the study, and acquisition carried out at 1.5T scanner. Cine-IR showed T1 values higher for viable myocardium than for non-viable. These and blood pool estimated T1, were found to be close to those reported in literatures. Dana C. Peters1, Reza Nezafat1, Peng Hu1, Yuchi Han1, Warren J. Manning1,2 1Cardiovascular Division, Beth Israel Deaconess Medical Center, Boston, MA, United States; 2Radiology, Beth Israel Deaconess Medical Center The CNR (blood-fibrosis) of Gd-BOPTA was compared to Gd-DTPA, using a high resolution late gadolinium enhancement technique with 0.2mmol/kg injection and a 15-40 minute delay. Eighteen patients were imaged with Gd-BOPTA, 8 of which were imaged with Gd-DTPA at another time point. The valves were studied as a surrogate for scar which adjacent to blood. The valve enhancement was greater using Gd-DTPA (p<0.05), Blood SNR was greater with Gd-BOPTA (p<0.05), and fibrosis blood CNR (measured in the valves) was greater for Gd-DTPA (p<0.05). Gd-DTPA outperformed Gd-BOPTA at this dose for visualizing the valve enhancement. Wiphada Patricia Bandettini1, Christine Mancini1, Peter Kellman1, Andrew Ernest Arai1 1National Heart, Lung, and Blood Institute, Laboratory of Cardiac Energetics, National Institutes of Health, Bethesda, MD, United States In this study, we present the use of multi-contrast delayed enhancement (MCODE) in trouble-shooting regions of high signal intensity within the myocardium that may be atypical delayed enhancement or may simply be blood pool adjacent to the epicardium and trabeculae. Our initial results show the utility of MCODE in clarifying questions of possible delayed enhancement beyond that of myocardial infarction. Furthermore, we demonstrate that a common region adjacent to the anteroseptum that has previously been thought to be blood pool between the septum and right ventricular moderator band or papillary muscle is in fact a tissue-based structure. Kerstin Ulrike Bauner1, Andreas Biffar2, Daniel Theisen1, Torleif Sandner1, Andreas Greiser3, Maximilian F. Reiser1, Bernd Wintersperger1 1Department of Clinical Radiology, LMU Munich - Campus Grosshadern, Munich, Germany; 2Josef Lissner Laboratory for Biomedical Imaging, LMU Munich - Campus Grosshadern, Munich; 3Siemens medical solutions At a given field strength tissues present with specific T1-values. We hypothesize, that infarcted myocardial tissue can be delineated from normal myocardium by means of T1-maps in unenhanced and contrast-enhanced (Gadobutrol) scans. Analysis of T1-values was performed for normal myocardium (MYO), infarcted myocardium (CMI) and the left ventricular cavity (LVC). In addition T1-ratios of MYO/LVC and CMI/LVC were calculated. T1-values of MYO and CMI and the calculated ratios of MYO/LVC and CMI/LVC were significantly differenent in pre-contrast and post-contrast scans. MR-measurements of T1-values with the LVC as a reference allow for a differentiation of infarcted areas from normal myocardial tissue.
Gyda S. Karlsdottir1, Sigurdur Sigurdsson1, Thor Aspelund1, Gudny Eiriksdottir1, Jie J. Cao2, Lenor Launer3, Tamara B. Harris3, Robert Detrano4, Andrew Arai5, Vilmundur Gudnason6 1Icelandic Heart Association Research Institute, Kopavogur, Iceland; 2National Heart, Lung and Blood Institute, Bethesda, United States; 3IRP, National Institute on Aging, Bethesda, United States; 4University of California Irvine,, Irvine, United States; 5IRP, National Heart, Lung and Blood Institute, Bethesda, United States; 6¹Icelandic Heart Association Research Institute, Kopavogur, Iceland Purpose of our study was to investigate the association of the extent of MI localized by gadolinium enhanced MRI, and the quantity of calcium in the coronary arteries detected with CT. Of the 674 subject, 21% had evidence of MI. Subjects with MI in all three coronary distributions had higher coronary calcium score (CCS), compared to those with MI in only one. Those with only one or two infarcted segments had significantly lower CCS than those with infarct in three or more segments. The relationship between the extent of MI and quantity of coronary calcium is significant and strong.
1292. Segmented T2-Prepared SSFP for Myocardial T2-Weighted Imaging and T2-Mapping Jeff A. Stainsby1, Graham A. Wright2 1Applied Science Laboratory, GE Healthcare, Toronto, Ontario, Canada; 2Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada Recent studies demonstrate that hyperintense regions in T2-weighted images in acute myocardial infarction (AMI) reflect the presence of edema and area at risk. Single-shot T2-prepared SSFP methods have been presented for T2-weighted imaging in AMI. Here a segmented SSFP approach suitable for multi-slice, multi-echo imaging of the myocardium is presented. 1293. A Comparison of Methods for T2-Mapping of the Myocardium Jeff A. Stainsby1, Venkat Ramanan2, Glenn S. Slavin3, Graham A. Wright2 1Applied Science Laboratory, GE Healthcare, Toronto, Ontario, Canada; 2Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; 3Applied Science Laboratory, GE Healthcare, Bethesda, MD, United States T2-weighted imaging in acute myocardial infarction has been suggested for detecting regions of edema. The need to carefully account for variations in coil sensitivity patterns has been noted with these techniques. An alternate approach is to generate quantitative T2 maps. In this work we compare 3 different myocardial T2 mapping methods; multi-echo double-IR FSE (MEFSE), segmented T2-prepared SSFP (T2pSSFP) similar to [1] and T2-prepared spiral (SpiralT2) [2]. James W. Goldfarb1,2, Wenguo Zhao1 1Saint Francis Hospital, Roslyn, NY, United States; 2Program in Biomedical Engineering, Stony Brook University, Stony Brook, NY, United States The aim of this study was to investigate the suitability of a three compartment pharmacokinetic model of late gadolinium-enhancement for chronic myocardial infarcts. Twenty-five individuals with chronic myocardial infarctions (MI) underwent MR imaging at 1.5T. Blood concentration was modeled with a bi-exponential and tissue concentration with a three compartment model, including vascular, free and trapping compartments. Fractional volumes and transfer constants into the compartments were fitted parameters of the model. It was found that a three compartment model is suitable for detailed modeling of chronic MI Gd-pharmacokinetics. This model provides further justification that fibrosis traps the Gd-contrast agent while Gd-concentrations in the free extracellular matrix remain similar with viable myocardium. Mao-Yuan Marine Su1, Ven-Cent Wu2, Hsi-Yu Yu3, Wen-Yih Isaac Tseng1,4 1Medical Imaging, National Taiwan University Hosptial, Taipei, Taiwan; 2Internal Medicine, National Taiwan University Hosptial, Taipei, Taiwan; 3Surgery, National Taiwan University Hosptial, Taipei, Taiwan; 4Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan For patients with primary aldosteronism (PA), aldosterone induced diffuse and microscopic fibrosis in the myocardium is difficult to be detected on the images of late gadolinium enhancement (LGE) MRI. In this study, we proposed a dynamic contrast enhancement method to detect the presence of microscopic fibrosis. In patients with PA, our results showed a significantly lower down-slope index (1.10”Ó0.16 vs. 1.29”Ó0.21; p=0.02) and a significantly higher end-point value index (0.88”Ó0.02 vs. 0.85”Ó0.03; p=0.04) compared to the normal subjects. These findings indicate the delayed wash-out and prolonged retention of the contrast medium in the myocardium, and suggest that there is increased amount of microscopic fibrosis in the myocardium. Therefore, we conclude that the proposed dynamic contrast enhancement method is capable of detecting the presence of microscopic fibrosis. Yue Zang1, Jie Zhou2, Jian Wu3, Zhao Qi Zhang 1Beijing Anzhen Hospital, Beijing, China; 2Beijing Anzhen Hospital, China; 3Beijing people's hospital of Peking University we use cardiac magnetic resonance (CMR) and dual-source CT to detect fatty tissue to confirm the morphologic change. 8 Of the 11 patients with lipomatous metaplasia were identified by CMR(72.7%); In 5 cases (62.5%), the thickness of the fatty tissue less than half of the scar. 1.5T cine- CMR showed wall thinner and akinesia or hypokinesia. Non-contrast black-blood T1-weighted spin echo images revealed a high signal with dramatic signal decay after fat saturation £¬indicating the presence of intramyocardial fat. CT plan scan and coronary CT showed hypodensity £Øfrom -56 to -113 HU£©in the myocardium, the location and extent consistent with CMR findings. Peter Kellman1, Diego Hernando2, Saurabh Shah3, Z-P Liang2, Andrew E. Arai1 1National Institutes of Health, Bethesda, MD, United States; 2University of Illinois, Urbana, IL, United States; 3Siemens Medical Solutions, Chicago, IL, United States Fat-water imaging in the heart is important for detection of intramyocardial fat and characterizing fibro-fatty infiltration seen in ARVD and chronic MI. A dark blood prepared fat/water separated imaging protocol has been developed which provides improved delineation of the myocardium. This should improve the ability to discern fatty infiltration of the thin walled RV. Lorenzo Mannelli1, Monvadi Barbara Srichai-Parsia2, Daniel Kim1, Xhafer Sinani2, Rajesh Hiralal1, Ruth P. Lim1 1Radiology, New York University, New Nork, United States; 2Radiology, Bellevue Hospital Center, New York, United States In this study we compare free-breathing balanced SSFP cine sequences (radial vs. Cartesian K space reconstruction) in a short series of consecutive patients. Radial acquisitions have the potentiality to be one of the possible strategies in patients who are unable to breath-hold or who have significant arrhythmias where segmented SSFP cine imaging is challenging and suboptimal for left and right ventricle function assessment. 1299. MR Imaging of Cardiac Wall-Motion at 1.5T and 7T: SNR and CNR Comparison Stefan Maderwald1,2, Kai Nassenstein, 12, Stephan Orzada1,2, Lena C. Schäfer1,2, Mark Oehmigen1, Andreas K. Bitz1,2, Oliver Kraff1,2, Irina Brote1,2, Susanne C. Ladd1,2, Mark E. Ladd1,2, Harald H. Quick1,3 1Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany; 2Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany; 3Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany Increased SNR and enhanced soft tissue contrasts are anticipated for 7T high-field MRI in comparison to 1.5T. The expected increases in SNR and CNR are of particular interest for high-resolution cardiac MR applications in humans. After addressing some of the 7T related transmit/receive problems, five healthy volunteers were imaged at 1.5T and 7T to measure and to compare SNR and CNR of cardiac function sequences along the short axis. It can be concluded that with the demonstrated increases in SNR and CNR, 7T cardiac function MRI with spoiled gradient echo at 7T outperforms cardiac function MRI with SSFP at 1.5T. 1300. Toward 7 Tesla Cardiac MRI for Clinical Application Stefan Maderwald1,2, Stephan Orzada1,2, Lena C. Schäfer1,2, Andreas K. Bitz1,2, Kai Nassenstein, 12, Oliver Kraff1,2, Irina Brote1,2, Mark Oehmingen1, Susanne C. Ladd1,2, Mark E. Ladd1,2, Harald H. Quick1,3 1Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, Germany; 2Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany; 3Institute of Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany Highfield MRI at 7T inherently offers higher signal-to-noise and enhanced soft tissue contrasts when compared to 1.5T or even 3T MRI, which might improve image quality in selected imaging applications like high-resolution cardiac MRI in humans. To push cardiac MRI at 7T another step further, a number of artifacts and imaging constraints related to 7T transmit/receive problems have to be addressed first. Additionally, protocols already established for 1.5T and 3T cardiac imaging have to be evaluated. This study presents two RF coil concepts to tackle some transmit/receive issues and evaluates established cardiac protocols which have been modified for application at 7T. 1301. NMR Molecular Profiling of Human Blood Plasma in Induced Myocardial Ischemia Jose Manuel Morales1, Fabian Chaustre2, David Moratal3, Vicent Bodi4, Daniel Monleon2 1Universitat de Valencia, Valencia, Spain; 2Fundacion Investigacion Hospital Clinico Valencia, Valencia, Spain; 3Center for Biomaterials and Tissue Engineering, Universitat Politecnica Valencia, Valencia, Spain; 4Hospital Clinico Universitario de Valencia, Valencia, Spain The protocols of management of patients entering emergency rooms because thoracic pain of potential ischemic origin without necrosis include serial measurement s of biomarkers, stress tests and, in many cases, unnecessary hospitalization. In this context, detection of metabolic markers, which represent dynamic changes in just a few minutes after ischemia, is an attractive option both for diagnosis precision and for rapid and efficient management. In this communication, we used NMR metabolic profiling to characterize metabolically blood plasma of patients pre and post angioplasty. Statistical multivariate analysis showed differences in signals belonging mainly to ketonic bodies and fatty acids. Myocardial Viability - Experimental Models Hall B Thursday 13:30-15:30 Benjamin Waghorn1,2, Wen Li3,4, Xin Yu3,4, Tom C.-C. Hu1,2 1Department of Radiology, Medical College of Georgia, Augusta, GA, United States; 2Nuclear and Radiological Engineering and Medical Physics Programs, Georgia Institute of Technology, Atlanta, GA, United States; 3Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; 4Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States Intracellular calcium overloading and structural changes are known to occur in the post-myocardial infarction (MI) heart. This study demonstrates the use of combined cardiac T1-mapping manganese-enhanced MRI and DTI in a mouse MI model to examine the relationship between indirect Ca2+ handling and structural modification during the myocardial remodeling process. Decreased Mn2+ uptake was observed for the infracted tissue, as well as the ischemic peri-infarct tissue, with a decrease in diffusivity and an increase in diffusion anisotropy also observed in the infarct hearts. Results from this study could provide a method for monitoring the salvageability of the peri-infarcted zone. Hyeyoung Moon1, Hyo Eun Park2, Quan-Yu Cai1, Jongeun Kang1, Kiyuk Chang2, Kwan Soo Hong1 1Magnetic Resonance Imaging Team, Korean Basic Science Institute, Ochang-Myun, Cheongwon-Gun, Korea, Republic of; 2Department of Internal Medicine, Catholic University, Seoul, Korea, Republic of In this study, we investigated whether magnetic nanoparticle-contrasted cardiac magnetic resonance imaging would be feasible and effective for the detecting the inflammation in a rat model of experimental autoimmune myocarditis, and whether MNP-contrasted CMR imaging could give a guidance where the biopsy samples should be collected. Walter RT Witschey1,2, James J. Pilla2, Giovanni Ferrari2, Keivn Koolmasingh2, Mohammed Haris1, Robin Hinmon2, Gerald A. Zsido1, Joseph H. Gorman III2, Robert C. Gorman2, Ravinder Reddy1 1Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Surgery, University of Pennsylvania, Philadelphia, PA, United States T1ρ MRI was performed to differentiate scar tissue, proximal, borderzone tissue and healthy myocardium in a swine model of left ventricular myocardial infarction. The spatially-dependent relaxation times were validated by histological staining of collagen and myocytes. Significant magnetic relaxation dispersion with the application of a varying amplitude RF field was observed. These results suggest that T1ρ is superior to conventional methods such as T2 for the visualization of early edema and late scarring and expansion in patients with ischemic cardiomyopathy. Martin Ugander1, Abiola J. Oki1, Peter Kellman1, Andreas Greiser2, Anthony H. Aletras1, Andrew E. Arai1 1National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States; 2Siemens AG Healthcare Sector, Erlangen, Germany T1-mapping of the heart before and after intravenous contrast administration can be used to generate quantitative pixel-maps of the extracellular volume (ECV) fraction of the myocardium in patients. The study presents comprehensive phantom, experimental and patient validation of the T1 mapping sequence (MOLLI) which is used to calculate ECV. The method provides images for quantitative assessment of the ECV of the myocardium, and in principle any other tissue, in a pixel map with a quantitative color scale ranging from 0-100%. Nilesh R. Ghugre1, Venkat Ramanan1, Mihaela Pop2, Yuesong Yang1, Jennifer Barry1, Beiping Qiang1, Kim Connelly3, Alexander J. Dick1, Graham A. Wright1,2 1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 2Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; 3Division of Cardiology, St. Michael's Hospital, Toronto, ON, Canada Pathophysiological responses after acute myocardial infarction (AMI) include edema, hemorrhage and microvascular obstruction (MVO) along with cellular damage. The in vivo evolution of these processes throughout infarct healing has not been well characterized. The purpose of our study was to monitor the time course of edema (T2), hemorrhage (T2*) and MVO in porcine myocardium following AMI and to observe the relative resolution of these pathophysiological mechanisms. Our study suggests that quantitative T2 and T2* mapping techniques are potentially more specific than intensity measures in single images, allowing regional, longitudinal and cross-subject comparisons. Such in vivo characterization will be important in grading severity and evaluating treatment strategies in AMI, potentially improving clinical outcome. 1307. On the Mechanism of Myocardial Edema Contrast in SSFP Imaging Xiangzhi Zhou1, Veronica Rundell1, Ying Liu1, Richard Tang1, Rachel Klein1, Shivraman Giri2, Saurabh Shah3, Sven Zuehlsdorff3, Orlando Simonetti2, Debiao Li1, Rohan Dharmakumar1 1Northwestern University, Chicago, IL, United States; 2Ohio State University, Columbus, OH, United States; 3Siemens Medical Solutions USA, Inc., Chicago, IL, United States The mechanism of bSSFP edema contrast in acute myocardial infarction imaging is not well understood. To assess the various mechanisms that enable the detection of myocardial edema on the basis on bSSFP imaging, controlled experiments were conducted in canine models subjected to ischemia reperfusion injury. Results show that relaxation and M0 changes have significant contribution to the detection of edematous myocardial zones following acute injury to the myocardium on the basis bSSFP imaging. 1308. On the Origin of Myocardial Edema Contrast in T2-STIR Images Xiangzhi Zhou1, Veronica Rundell1, Ying Liu1, Richard Tang1, Rachel Klein1, Shivraman Giri2, Saurabh Shah3, Sotirios A. Tsaftaris1, Sven Zuehlsdorff3, Orlando Simonetti2, Debiao Li1, Rohan Dharmakumar1 1Northwestern University, Chicago, IL, United States; 2Ohio State University, Columbus, OH, United States; 3Siemens Medical Solutions USA, Inc., Chicago, IL, United States The biophysical mechanisms contributing to myocardial edema contrast in T2-weighted STIR images was studied using dogs subjected to ischemia-reperfusion injury. It is shown that in addition to T2-weighting, edema detection in acute myocardial infarcts with T2-weighted STIR images have substantial weighting from proton density changes. This finding suggests that myocardial edema detection sensitivity is enhanced when acquisition strategies permit sensitivity to proton density, as well as T2 changes. Myocardial Perfusion: Experimental Model & Human Studies Hall B Monday 14:00-16:00 1309. Arterial Spin Labeled MRI Detects Increase in Myocardial Blood Flow with Adenosine Zungho Zun1, Padmini Varadarajan2, Ramdas G. Pai2, Eric C. Wong3, Krishna S. Nayak1 1Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States; 2Division of Cardiology, Loma Linda University Medical Center, Loma Linda, CA, United States; 3Departments of Radiology and Psychiatry, University of California, San Diego, La Jolla, CA, United States Myocardial arterial spin labeling (ASL) scans were performed at rest and during adenosine infusion in eleven patients scheduled for CMR. Seven patients were classified as normal based on having no visible perfusion defect on CMR first-pass imaging. In these subjects, there was a statistically significant increase in global myocardial blood flow (MBF) measured during adenosine infusion (3.75 ± 1.06 ml/g/min), compared to at rest (1.09 ± 0.53 ml/g/min). This suggests that myocardial ASL may be capable of capturing clinically relevant increases in MBF with vasodilation. Michael L. Cobert1, Matthias Peltz1, Matthew E. Merritt2, LaShondra M. West1, Larry Ammann3, Michael E. Jessen1 1Cardiovascular and Thoracic Surgery, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, United States; 2Advanced Imaging Research Center, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, United States; 3Mathematics, University of Texas at Dallas, Dallas, TX, United States Perfusion preservation of donor hearts appears promising for extending the donor ischemic interval and utilization of extended donors. A major risk of using so-called marginal donors is predicting the viability of the graft. The current study utilizes proton magic angle spinning spectroscopy to determine biomarkers of perfusion preservation. These data suggest MAS MRS may be useful for determining heart function prior to implantation 1311. Three-Dimensional Myocardial Perfusion MRI Using SW-CG-HYPR Lan Ge1, Heng Ma2, Aya Kino1, James Carr1, Kuncheng Li, Debiao Li1 1Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States; 2Xuanwu Hospital and Capital Medical University, Beijing, China Image quality and spatial coverage for myocardial perfusion MRI are limited in current approaches. In this work, we developed a 3D inversion recovery (IR) prepared Turbo-FLASH sequence with radial sampling, combined with SW-CG-HYPR for myocardial perfusion MR imaging. Using this method, the acquisition time per partition in each cardiac cycle was reduced dramatically, and 6 partitions were acquired after each IR pre-pulse. The signal changes of the left ventricle and myocardium were verified by comparison to conventional methods. Mean correlation coefficients between 3D SW-CG-HYPR and reference images are 0.98, 0.96 for blood and myocardial signals, respectively. Jiongjiong Wang1, Xiaoming Bi2, Tongbai Meng3, Sven Zuehlsdorff2, John A. Detre4 1Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL, United States; 3Center for Applied Medical Imaging, Siemens Corporate Research, Baltimore, MD, United States; 4Neurology, University of Pennsylvania, Philadelphia, PA, United States Arterial spin labeling (ASL) has been applied for noninvasive measurement of myocardial blood flow (MBF), yet the reliability is not optimal due to the requirement for repeated breath holding. We developed a cardiac ASL technique for reliable clinical applications dubbed FREE-breathing Myocardial ASL with Navigator-echo (FREEMAN). Dynamic myocardial perfusion signals were measured at multiple delays. The estimated mean MBF was 103±56ml/100g/min with a mean transit time of approximately 400ms and moderate to high test-retest reliability. 1313. 4D BSSFP Myocardial BOLD Imaging with Flow Compensation: Early Results Xiangzhi Zhou1, Zhaoyang Fan1, Richard Tang1, Rachel Klein1, Debiao Li1, Rohan Dharmakumar1 1Northwestern University, Chicago, IL, United States Cardiac phase-resolved 3D BOLD bSSFP imaging with first-order gradient moment compensation was studied in healthy dogs and those with coronary artery stenosis in the presence of adenosine stress. Flow/motion artifacts were greatly reduced in 3D cine bSSFP images in the presence of flow compensation compared to no flow compensation. In the presence of adenosine infusion, LCX stenosis led to a discriminating signal loss in the inferior walls that was readily visible in all cardiac phases in the flow compensated 3D cine bSSFP images. 1314. Myocardial BOLD Imaging Using Flow Compensated 2D Cine BSSFP Xiangzhi Zhou1, Sotirios A. Tsaftaris1, Ying Liu1, Richard Tang1, Rachel Klein1, Sven Zuehlsdorff2, Debiao Li1, Rohan Dharmakumar1 1Northwestern University, Chicago, IL, United States; 2Siemens Medical Solutions USA, Inc., Chicago, IL, United States Robust image quality is critical for reliable detection and evaluation of myocardial oxygenation changes with bSSFP BOLD imaging. This work evaluates the utility of 2D first-order motion compensation scheme to minimize flow/motion artifacts in cardiac phase-resolved bSSFP BOLD imaging using canines. Results show that compared to non-flow compensated bSSFP BOLD method, the proposed approach permits the evaluation of BOLD changes originating from coronary stenosis throughout the cardiac cycle. 1315. Myocardial BOLD Imaging at 3T Using Quantitative T2: Application in a Myocardial Infarct Model Nilesh R. Ghugre1, Venkat Ramanan1, Mihaela Pop2, Yuesong Yang1, Jennifer Barry1, Beiping Qiang1, Kim Connelly3, Alexander J. Dick1, Graham A. Wright1,2 1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 2Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; 3Division of Cardiology, St. Michael's Hospital, Toronto, ON, Canada Coronary vasodilatory dysfunction has been shown in infarcted as well as remote myocardium in patients with acute coronary syndrome. Our study demonstrates the utility of T2-based BOLD effect in probing regional and longitudinal fluctuations in vasodilatory function in a porcine model of myocardial infarction at 3T. T2 measurements were performed in remote and infarcted myocardium at rest and after Dipyridamole-induced vasodilation (stress). Experimental observations indicated that T2 at 3T offers greater sensitivity towards detecting changes in myocardial oxygenation compared to 1.5T, consistent with a two-compartment theoretical model. Stress-induced vasodilatory response using quantitative T2 can help evaluate remote-zone vascular function and potentially identity salvageable myocardium in the infarct zone. MRS of the Heart Hall B Tuesday 13:30-15:30 1316. MRI/MRS Biomarkers for Response Evaluation in Patients with CABG Zhuoli Zhang1, Shengyong Wu2, Ying Liu3, Savita Puri4, Shara Ramaswamy5, Yi Huan3, Debiao Li1 1Northwestern University, Chicago, IL, United States; 2Tianjin Medical University; 3Fourth Military Medical University; 4University of Rochester Medical Center; 5Florida International University Phosphorus-31 magnetic resonance spectroscopy (31P-MRS) represents a unique instrument to noninvasively monitor myocardial metabolism in humans. The technique has been used to study the metabolism in myocardium in patients with coronary artery disease (CAD). The measurements permit quantitative estimation of the phosphocreatine (PCr)/adenosine triphosphate (ā-ATP) ratio which reflects the energetic state of the myocardium. Previous studies investigated the effect of successful coronary artery bypass grafting surgery (CABG) upon left ventricular function. Although residual myocardial viability in patients with CAD and extensive regional asynergy is associated with improved ventricular function after CABG, the relationship between myocardial metabolism and heart function after CABG remains unclear. We hypothesized that cardiac function benefits from high-energy phosphate (HEP) and sought to investigate the relationship between HEP and cardiac function in CAD patients using cine magnetic resonance imaging (cine-MRI) and 31P-MRS. Vera Schrauwen-Hinderling1, Lena Bilet1, Tineke van de Weijer1, Matthijs Hesselink1, Jan Glatz1, Joachim Wildberger1, Michael Schär2,3, Eline Kooi1, Patrick Schrauwen1 1Maastricht University Medical Center, Maastricht, Netherlands; 2Johns Hopkins University, Baltimore, United States; 3Philips Health Care, Cleveland, United States Excessive lipid accumulation in the myocardium may predispose to cardiomyopathy. Elevated plasma (free) fatty acids (FA) might be a risk factor herein. Cardiac lipid content was determined by 1H-MRS in healthy men (fasted state). Subsequently, subjects cycled for two hours and rested for three hours, after which cardiac lipid content was measured again. All subjects performed this protocol twice: once fasted and once while ingesting glucose to keep FA low. Cardiac lipid content was elevated after the fasted test day but unchanged when glucose ingestion kept FA low. This suggests that FA are important in determining cardiac lipid content. 1318. The Role of Cardiac Carbonic Anhydrases in Vivo: A Hyperpolarised 13C MR Study Marie Allen Schroeder1, Pawel Swietach1, Philip Lee2, Ferdia A. Gallagher3,4, Ben Rowlands1, Claudiu T. Supuran5, Kevin M. Brindle, 4,6, Richard D. Vaughan-Jones1, George K. Radda1,2, Kieran Clarke1, Damian J. Tyler1 1Physiology, Anatomy and Genetics, University of Oxford, Oxford, Oxfordshire, United Kingdom; 2Biomedical Sciences Institute, Singapore Bioimaging Consortium, Singapore, Singapore; 3Radiology, Addenbrooke's Hospital, University of Cambridge, Cambridge, United Kingdom; 4Li Ka Shing Centre, CRUK Cambridge Research Institute, Cambridge, United Kingdom; 5Dipartimento di Chimica, University of Florence, Florence, Italy; 6Biochemistry, University of Cambridge, Cambridge, United Kingdom Carbonic anhydrase (CA) catalyses the hydration of CO2 to form HCO3- and H+, an inter-conversion which serves as a major pH buffer in blood plasma and inside cells. To date, cardiac isoforms of CA have only been studied in vitro, where their function could be drastically different than in vivo. The aim of this study was to determine the effects of intra- and extracellular isoforms of CA on CO2 efflux from the heart, in vivo, based on MRS detection of 13CO2 generated from the metabolism of hyperpolarised [1-13C]pyruvate. Our results indicated that extracellular CAs do not affect cardiac CO3 removal under control perfusion conditions, though may have a role in ischemia. Further, we observed that intracellular CA activity trapped HCO3- and H+ within the myocyte, which could potentially acidify the intracellular space. Physiological levels of cardiac intracellular CA must balance retention of myocardial bicarbonate to buffer potential acid/base disturbances, without causing excessive intracellular acidification. 1319. Evaluation for Optimal Stress System for Cardiac MR Study Hee-Won Kim1,2, Karam Souibri3, Gerald M. Pohost1,4 1Radiology, University of Southern California, Los Angeles, CA, United States; 2Cardiology, Heart and Vascular Institute, Hollywood Presbyterian Hospital, Los Angeles, CA, United States; 3Cardiology, University of Southern California, Los Angeles, CA, United States; 4Electrical Engineering, University of Southern California, Los Angeles, CA, United States A stress control system was developed and evaluated to obtain improved precision of the stress MR studies. The stability in stress was achieved by the feed-forward or feedback control and audio-visual stimulation actuated by the error signal. The system performance was evaluated by cardiac P-31 MRS at 3T. With the control system, it was clearly demonstrated that the stress level is far more stable during the entire session and inter-subject variation in the metabolic alterations is significantly reduced. It is expected to assess cardiac function and metabolite alteration during moderate stress with higher precision by using automatic stress control system. Adrianus Johannes Bakermans1, Sander M. Houten2, Tom R. Geraedts1, Michel van Weeghel2, Klaas Nicolay1, Jeanine J. Prompers1 1Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 2Laboratory Genetic Metabolic Diseases, Academic Medical Centre, Amsterdam, Netherlands A respiratory gated, cardiac triggered PRESS 1H-MRS sequence was used to investigate effects of fasting on lipid content in the long chain acyl-coenzyme A dehydrogenase knockout (LCAD-/-) mouse heart. Left ventricular (LV) function and morphology were assessed using cine MRI. LV mass normalized to body weight was larger in LCAD-/- mice than in controls, indicating LV hypertrophy. There was a trend for a decrease in ejection fraction after fasting, accompanied by increased lipid content in LCAD-/- mice compared to controls. It remains to be established whether there is a causal relationship between increased myocardial lipid content and decreased cardiac function.
1321. Navigator Gated and Cardiac Triggered Echo-Planar Spectroscopic Imaging of the Heart Kilian Weiss1, Nicola Martini2, Peter Boesiger1, Sebastian Kozerke1 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; 2Interdepartmental Research Center "E. Piaggio", University of Pisa, Pisa, Italy Single-voxel proton magnetic resonance spectroscopy has been shown to be a promising tool for assessing creatine and myocardial triglycerides in humans. While spectral information from a single volume is sufficient when alterations with global effects on the heart are studied, a demand for higher and flexible spatial resolution exists when probing local changes. To this end, implementation of fast spectroscopic imaging of the heart is desired. The objective of the current work was to implement and optimize navigator gated and cardiac triggered Echo-Planar Spectroscopic Imaging (EPSI) for assessment of triglyceride and creatine content in the myocardium in vivo. Vera Schrauwen-Hinderling1, Ruth Meex1, Jan Glatz1, Joachim Wildberger1, Hildo Lamb2, Michael Schär3,4, Matthijs Hesselink1, Patrick Schrauwen1, Marianne Eline Kooi1 1Maastricht University Medical Center, Maastricht, Netherlands; 2Leiden University Medical Center, Leiden, Netherlands; 3Johns Hopkins University, Baltimore, United States; 4Philips Health Care, Cleveland, United States Excessive cardiac lipid storage might hamper cardiac function via lipotoxic pathways. We investigated the response of cardiac lipids to exercise training in patients with type 2 diabetes mellitus. Maximal whole body oxygen uptake and LV-ejection fraction (by CINE-MRI) were improved while cardiac lipid content (by 1H-MRS) was unchanged after training. This is in contrast to our earlier findings in healthy overweight subjects, where such a training intervention diminished cardiac lipid content. This may indicate hampered exercise-induced lipid mobilization in the diabetic heart and reveals that reduction of cardiac lipids is not a prerequisite for the training-induced improvement in cardiac function. 1323. Myocardial Steatosis Is Associated with Regional Ventricular Dysfunction Chia-Ying Liu1, Alban Redheuil1, Elzbieta Chamera1, Joao Lima1, David Bluemke2, Shenghan Lai3 1Department of Radiology, Johns Hopkins Hospital, Baltimore, MD, United States; 2Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD, United States; 3Department of Epidemiology, Johns Hopkins School of Hygiene and Public health, Baltimore, MD, United States The increased myocardial triglyceride pool is associated with impaired myocardial function in animal experiments. Human studies also indicate that myocardial steatosis is associated with impaired left ventricular filling dynamics and diastolic dysfunction. Proton Magnetic Resonance Spectroscopy (1H-MRS) has proven to be reliable and reproducible in measuring myocardial triglyceride content in humans. The primary goal of the present study was to evaluate the myocardial fat content in cardiovascularly asymptomatic HIV infected and non-infected individuals using 1H-MRS, and to correlate the septal triglyceride content to the regional ventricular function measured by tagged MRI. 1324. Intramyocardial Lipid Quantification by MRS: in Vivo Validation in Human Subjects Robert D. O'Connor1, Jian Xu2, Linda R. Peterson3, Gropler J. Robert1, Adil Bashir1 1Radiology, Washington University, St. Louis, MO, United States; 2Siemens, NY, United States; 3Internal Medicine, Washington University, St. Louis, MO, United States An MRS assay of myocardial lipid is characterized and its accuracy and specificity cross-validated with ex vivo high resolution NMR measurements via endomyocardial biopsies from heart transplant patients. Ming Lu1,2, Jessica Spires1, Gheorghe D. Mateescu2,3, Chris Flask2,4, Xin Yu1,2 1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; 2Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States; 3Chemistry, Case Western Reserve University; 4Radiology, Case Western Reserve University, Cleveland, OH, United States Cardiac applications of 17O NMR for evaluating mitochondrial function have been limited due to the challenge of detecting metabolic H217O in the vast background of natural abundance H217O. In this study, we developed a direct 17O MR Spectroscopy (MRS) approach to examine the feasibility and sensitivity of detecting metabolically produced H217O in isolated rat hearts perfused with 17O2-enriched Krebs buffer. Mitochondrial production of H217O was monitored by dynamic 17O spectroscopy. Oxygen consumption rate (MVO2) was determined by least-square fitting of a compartmental model to NMR data. An increase of MVO2 was observed under elevated workload induced by high Ca2+ concentration. 1326. In Vivo T1 Mapping of 31P Metabolites at Short TR Mahon L. Maguire1, Hannah Barnes1, Stefan Neubauer1, Jurgen E. Schneider1 1Dept Cardiovascular Medicine, University of Oxford, Oxford, Oxon, United Kingdom Quantitation of the energetics of the heart requires accurate tissue specific T1 values for the 31P metabolites involved. Acquisition of 31P spectroscopic data at high resolution necessitates the use of a short TR relative to the T1 of the metabolites. High resolution 31P chemical shift imaging was employed to take spatially resolved 2, 3 and 4 flip angle T1 measurements. Phantom studies are presented investigating the optimal parameters for T1 mapping in vivo. A dual angle T1 measurement employing flip angles of 30 and 15° is optimal where TR/T1<0.2; its application in the mouse is presented. 1327. Performance of a Phased Array for 31P Cardiac MR Spectroscopy Christopher T. Rodgers1, Lowri E. Cochlin2, Damian J. Tyler2, Stefan Neubauer1, Matthew D. Robson1 1Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, United Kingdom; 2Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom Cardiac 31P spectra of high-energy phosphorus metabolites are typically acquired using a transmit/receive surface coil. In MR imaging, single element surface coils have largely been superseded by receive arrays, which provide higher signal-to-noise ratios (SNRs) and larger fields of view (FOVs). We present the first receive array cardiac 31P spectra at 3T. Comparing with an established protocol in 8 normal volunteers, we observe larger FOV and homogeneity, increased comfort, and an enhancement in SNR comparable to that from NOE. Our 8-element array contains for the first time posterior elements, which contribute up to 35% at the posterior of the heart. Giovanni Di Leo1, Alexis Malavazos, Francesco Secchi, Calin Coman, Lelio Morricone, Massimiliano Marco Corsi, Gianluca Iacobellis2, Francesco Sardanelli1 1Unit of Radiology, Universitą degli Studi di Milano, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy; 2McMaster University We assessed whether the epicardial adipose tissue (EAT) thickness is associated to the septal myocardial fat (SMF). Ten obese volunteers underwent echocardiographic EAT thickness measurement, 1.5-T 1H-MRS for SMF quantification (water reference) and MRI for EAT volume estimation. Intra- and interobserver reproducibility was excellent. SMF was 1-9%, EAT volume was 5-43 mL and EAT thickness was 3-11 mm. SMF showed a high correlation with EAT thickness, EAT volume, left ventricle mass and waist circumference. In multivariate regression, the EAT thickness was the only significant covariate of the SMF. We can speculate that EAT accumulation could reflect SMF in obese individuals. Karlos X. Moreno1, Scott Sabelhaus1, Matthew E. Merritt1, A Dean Sherry1, Craig R. Malloy1 1Advanced Imaging Research Center, Univ of TX Southwestern Med Ctr, Dallas, TX, United States The effect of [3-13C]pyruvate on [lactate] and [alanine] was studied in Langendorff-mode rat hearts. A 90 second perfusion with 2 mM [3-13C]pyruvate increased [lactate] and [alanine]. During the inhibition of aminotransferases by AOA, an increase in [alanine] was not observed, but, unexpectedly, [lactate] did not increase either. Lactate production was inhibited due to the lack of NADH replenishment from the malate-aspartate shuttle. These results support a reversal of the malate-aspartate shuttle to provide NADH for the production of lactate following a rapid increase in [pyruvate]. Ronald Ouwerkerk1, Ahmed Medhat Gharib1, Khaled Zakarya Abd-Elmoniem1, Kong Y. Chen2, Jatin Raj Matta1, Monica C. Skarulis2 1Cardiovascular Imaging, NIH, NIDDK, Bethesda, MD, United States; 2Clinical Endocrinology, NIH, NIDDK, Bethesda, MD, United States To study effects of obesity on lipid metabolism in the muscles, heart and liver we studied obese subjects with localized MRS in heart, liver and leg muscles. A protocol comprising cardiac cine- and tagged MRI, water-fat images of liver, thigh and calf and a visceral fat determination was executed in a wide-bore 3T whole body magnet on subjects with body mass indices 41-62, weights 99-152kg. MRS data from PRESS with cardiac, navigator gating and outer volume suppression to reduce motion artifacts and contamination from surrounding fat proved feasibility of measuring cardiac, liver and skeletal muscle lipid content in obese subjects. Flow Quantification: Vessel Function Hall B Wednesday 13:30-15:30 1331. T2-Weighted Fourier Velocity Encoding: MR Oximetry in Small Vessels Christopher Marek Wernik1, Venkat Ramanan2, Graham A. Wright1,2, Christopher K. Macgowan1,3 1Dept. of Medical Biophysics, University of Toronto, Toronto, ON, Canada; 2Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 3Dept. of Diagnostic Imaging, Hospital for Sick Children, Toronto, ON, Canada MR oximetry based on quantitative T2 measurement is a noninvasive technique for measuring blood oxygen saturation. However, partial volume effects limit T2 accuracy in narrow vessels or impose long scan times at reduced SNR. In this study, we propose an improved technique which uses Fourier velocity encoding to control for partial volume effects and test its feasibility using an apparatus that mimics constant blood flow in a vessel. The results show that the proposed technique is more accurate than conventional MR oximetry in the presence of partial volume effects. Considerations for in vivo application are discussed. 1332. Evaluation of Different Techniques for Measuring Pulse Wave Velocity Using 3 Tesla MRI Elsayed H. Ibrahim1, Kevin R. Johnson1, Jean M. Shaffer1, Richard D. White1 1University of Florida, College of Medicine, Jacksonville, FL, United States Arterial stiffness can be noninvasively estimated by measuring pulse wave velocity(PWV) from velocity-encoded MR images using different methods: transit-time(TT), flow-area(QA), and cross-correlation(XC). However, the reproducibility and comparison of these different techniques have not yet been studied in a large diverse group of patients for relative durability and reproducibility, especially at 3T field. In this work, the aortic PWV is measured in 50 patients, representing a wide range of cardiovascular conditions, to assess inter-observer, intra-observer, inter-scan, and inter-method variabilities using 3T MRI. The TT method resulted in the most-reproducible measurements and required the shortest processing-time, followed by XC and QA. 1333. Accelerated Dual Velocity Encoded Phase Contrast VIPR Elizabeth Janus Nett1, Kevin M. Johnson1, Christopher J. Francois2, Darren Lum2, Oliver Wieben, 2,3 1Medical Physics, University of Wisconsin , Madison, WI, United States; 2Radiology, University of Wisconsin, Madison, WI, United States; 3Medical Physics, University of Wisconsin, Madison, WI, United States We present a method for improving the VNR in 3D radial undersampled phase contrast exams using an accelerated dual Venc acquisition. This method will allow for more accurate velocity measurements and advanced hemodynamic analysis, particularly in vascular areas that have wide ranges of velocities of interest such as arterial and venous systems . 1334. Probabilistic Flow Connectivity Mapping Ola Friman1, Anja Hennemuth1, Andreas Harloff2, Jelena Bock3, Michael Markl3, Heinz-Otto Peitgen1 1Fraunhofer MEVIS, Bremen, Germany; 2Neurology and Clinical Neurophysiology, Albert-Ludwigs Universität, Freiburg, Germany; 3Diagnostic Radiology, Medical Physics, Albert-Ludwigs Universität, Freiburg, Germany Standard techniques for visualizing and quantifying flow data obtained with phase contrast (PC) MRI treat the measurements as if they were free of noise. This practice may lend the results a false sense of precision. This work contributes a flow connectivity mapping algorithm that models the noise in PC MRI velocity measurements and visualizes the flow uncertainty as a probabilistic flow distribution. New probabilistic measures such as the assignment of likelihoods to flow pathways to evaluate mixing of blood, or to quantify embolization probabilities in stroke and infarction, are also envisaged. Valentina Taviani1, Stacey S. Hickson2, Christopher J. Hardy3, Andrew James Patterson1, Carmel M. McEniery2, Ian B. Wilkinson2, Jonathan Harvey Gillard1, Martin J. Graves1 1Department of Radiology, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom; 2Clinical Pharmacology Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom; 3GE Global Research, Niskayuna, NY, United States Age-related changes of regional aortic compliance play a crucial role in the pathophysiology of cardiovascular disease. Fourier velocity encoded (FVE) M-mode can produce Doppler-like time-velocity traces with high temporal and spatial resolution along relatively straight arterial segments. In this work, FVE M-mode was used to measure global and regional pulse wave velocity (PWV) in the descending aorta of 56 healthy subjects. A significant nonlinear relationship between overall PWV and age was found (r2=0.73, p<0.001). The distal thoracic aorta was found to stiffen the most with age, followed by the proximal and distal abdominal aorta. Valentina Taviani1, Andrew James Patterson1, Martin J. Graves1, Christopher J. Hardy2, Pauline W. Worters3, Michael P. Sutcliffe4, Jonathan Harvey Gillard1 1Department of Radiology, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom; 2GE Global Research, Niskayuna, NY, United States; 3Department of Radiology, Stanford University, Lucas Center, Stanford, CA, United States; 4Department of Engineering, University of Cambridge, Cambridge, United Kingdom Accuracy and repeatability of pulse wave velocities (PWVs) obtained from Fourier velocity encoded (FVE) M-mode and 2D phase contrast (PC) with through-plane velocity encoding were investigated using five different analysis techniques. Accuracy was tested on a tubular human-tissue-mimicking phantom integrated into a flow simulator. The gold standard was obtained from the Moens-Korteweg equation after measurement of the tube elastic modulus by uniaxial tensile testing. Repeatability was evaluated across three MR visits. Similarly accurate results were obtained with the two MR techniques, provided the optimal algorithm was used. M-mode PWVs were more repeatable than PC PWVs, regardless of the analysis technique. 1337. Are There General Protocol Parameters to Reduce Velocity Offsets? a Multi-Vendor Study. Marijn P. Rolf1, Mark B.M. Hofman1, Peter D. Gatehouse2, Karin Markenroth Bloch3, Martin J. Graves4, Albert C. van Rossum5, Philip Kilner2, Rob M. Heethaar1 1Physics and Medical Technology, ICaR-VU, VU University Medical Center, Amsterdam, Netherlands; 2Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, United Kingdom; 3Philips Healthcare, Lund University Hospital, Lund, Sweden; 4Department of Radiology, Addenbrooke's Hospital, Cambridge, United Kingdom; 5Department of Cardiology, ICaR-VU, VU University Medical Center, Amsterdam, Netherlands Velocity offsets are of great concern for accuracy in cardiovascular flow quantification measurements. General protocol parameters (gradient speed, read-out bandwidth, partial echo, venc, and slice thickness) were studied across several MR-scanners of different vendors to investigate whether there is a general rule by which volume flow quantification protocols can be optimized in order to reduce velocity offsets. Gradient speed and partial echo showed a clear effect on the velocity offsets but not across all vendors. Slice orientation was found to be of major influence across all scanners, oblique slices generally gave higher offsets. 1338. Optimal Bipolar Gradient Design to Reduce Velocity Offsets. Marijn P. Rolf1, Mark B.M. Hofman1, Peter D. Gatehouse2, Albert C. van Rossum3, Rob M. Heethaar1 1Physics and Medical Technology, ICaR-VU, VU University Medical Center, Amsterdam, Netherlands; 2Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, London, United Kingdom; 3Department of Cardiology, ICaR-VU, VU University Medical Center, Amsterdam, Netherlands Uncompensated eddy-currents cause velocity offsets, resulting in significant errors in clinical flow quantification. To reduce these offsets, the influence of velocity encoding gradient settings was studied in detail. Specifically the bipolar gradient timing, velocity encoding strategy (asymmetric or symmetric), and gradient amplitude and slew rate were studied. Timing showed no correlation with offset. Symmetrical encoding resulted in significantly lower offsets. Velocity offsets were also reduced by lowering the gradient amplitude and slew rate, however those protocols are not always compatible with the time-constraints of breath-hold imaging. 1339. Nontriggered Cartesian Steady-State Free Precession Phase-Contrast MR Joshua FP van Amerom1, Michael S. Jansz1, Christopher K. Macgowan1 1Departments of Medical Biophysics and Medical Imaging, University of Toronto and Hospital for Sick Children, Toronto, Ontario, Canada Steady state free precession phase-contrast (PC-SSFP) is proposed for measurement of nontriggered time-averaged velocity as it exhibits less signal variation over the cardiac cycle than conventional PC-MR. It is shown that Cartesian nontriggered PC-SSFP provides an accurate mean-velocity measurement while conventional nontriggered PC-MR overestimates the mean velocity due to in-flow effects. John James Totman1,2, René M. Botnar3, Penny A. Gowland4, Andrea J. Wiethoff3,5 1Kings College London BHF Centre, Division of Imaging Sciences, NIHR Biomedical Research Centre at , London, United Kingdom; 2Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingah, United Kingdom; 3Kings College London BHF Centre, Division of Imaging Sciences, NIHR Biomedical Research Centre at, London, United Kingdom; 4Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, United Kingdom; 5Philips Healthcare, Best, Netherlands This study describes the phasic temporal flow profiles of blood flow of the RCA as measured at different specific lung pressures. Mathematical modelling was able to identify significant changes in phasic temporal flow profiles when no statistically significant differences in flow where detected. Clinically relevant additional information may be gained by using higher temporal and spatial PC-MRI blood flow measurements of the RCA as progressively more information is identified within the phasic temporal flow profiles of blood flow. 1341. Whole Heart Flow Sensitive 4D MRI in Congenital Heart Disease Julia Geiger1, Raoul Arnold2, Alex Frydrychowicz3, Brigitte Stiller2, Mathias Langer1, Michael Markl1 1Diagnostic Radiology and Medical Physics, University Hospital Freiburg, Freiburg, Baden-Wuerttemberg, Germany; 2Pediatric Cardiology, University Hospital Freiburg; 3Diagnostic Radiology , University of Wisconsin The aim of this study was to assess the vessel morphology and altered hemodynamics in patients with operated congenital heart disease by flow sensitive whole heart 4D MRI. 15 patients with heterogeneous heart defects were examined on 1.5 or 3 T MRI scanners using a gradient echo sequence with interleaved 3-directional velocity encoding. Postoperative altered hemodynamics including flow acceleration or vortex formation could be visualized and characterized. Therefore, we take the method to be a promising modality for acquisition of comprehensive flow behavior and better understanding of extraordinary flow profiles in congenital heart disease.
1342. Simulation of Phase-Contrast MRI Intravoxel Velocity Standard Deviation (IVSD) Mapping Sven Petersson1, Petter Dyverfeldt1, Roland Gårdhagen1, Matts Karlsson1, Tino Ebbers1 1Linköping University and Center for Medical Image Science and Visualization (CMIV), Linköping, Sweden Disturbed blood flow, characterized by velocity fluctuations, accompanies many cardiovascular diseases. PC-MRI intravoxel velocity standard deviation (IVSD) mapping permits the quantification of the intensity of these velocity fluctuations; turbulence intensity. Here, a PC-MRI IVSD measurement in stenotic flow was simulated using computational fluid dynamics (CFD) data obtained by large eddy simulations. The PC-MRI simulation showed overall strong similarities the CFD simulation and in-vitro measurement. The simulation of PC-MRI of fluctuating flow may facilitate controlled studies of the effects of velocity fluctuations on the PC-MRI signal and the optimization of IVSD mapping. Marcus T. Alley1, Philip J. Beatty2, Albert Hsiao1, Shreyas S. Vasanawala1 1Radiology, Stanford University, Stanford, CA, United States; 2MR Applied Science Lab, GE Healthcare, Menlo Park, CA, United States Time-resolved 3-dimensional phase-contrast MR imaging (3D-PC MRI) has developed as an active area of research for vascular imaging. In general however the clinical adoption of this approach for routine vascular imaging has been hampered by the long acquisition times inherent in the technique (on the order of 10-20 minutes). Several groups have addressed this issue by using parallel imaging to accelerate data acquisition in one dimension, and in this work we demonstrate the ability to perform auto-calibrated parallel imaging in both the in-plane and slice directions to reduce the overall scan time to the order of several minutes. Jonathan D. Suever1, David Huneycutt2, Enrique Rojas-Campos3, Francesca Cardarelli3, Sam Fielden2, Arthur Stillman, 2,3, Paolo Raggi3, John N. Oshinski, 12 1Biomedical Engineering, Georgia Institute of Technology / Emory University, Atlanta, GA, United States; 2Radiology, Emory University School of Medicine, Atlanta, GA, United States; 3Cardiology, Emory University School of Medicine, Atlanta, GA, United States Increased aortic pulse wave velocity (PWV) due to arterial stiffening is commonly seen in patients with hypertension. Clinically, applanation tonomtery is used to measure PWV; however, we have developed a new method that uses PCMR combined with cross-correlation analysis. The purpose of this study was to compare the reproducibility of cross-correlation and applanation tonometry in normals and patients. In normal volunteers, the reproducibility of cross-correlation technique was better than applanation tonometry. In patients, cross-correlation and applanation tonometry measurements were not statistically different. Jonatan Eriksson1, Petter Dyverfeldt1, Jan Engvall1, Ann F. Bolger2, Tino Ebbers1, Carl-Johan Carlhäll1 1Linköping University and Center for Medical Image Science and Visualization (CMIV), Linköping, Sweden; 2University of California San Francisco, San Francisco, CA, United States Multidimensional patterns of intracardiac blood flow remain poorly characterized in health and disease. An extended pathline based left ventricular (LV) 4D blood flow quantification approach is presented. Three-directional, three-dimensional cine phase-contrast MRI data was acquired in healthy subjects and patients with idiopathic dilated cardiomyopathy and analyzed for assessment of the pre-systolic LV blood flow organization, in order to evaluate the preparation of different flow components for systolic outflow. Quantification of pre-systolic orientation may reflect an aspect of ventricular systolic efficiency that is impacted by flow-specific organization inside the diastolic ventricle. 1346. Aortic Pulse Pressure Evaluation Using Fourier Velocity Encoded MR M-Mode Valentina Taviani1, Stacey S. Hickson2, Christopher J. Hardy3, Andrew James Patterson1, Victoria E. Young1, Mark Butlin4, Carmel M. McEniery2, Ian B. Wilkinson2, Jonathan Harvey Gillard1, Martin J. Graves1 1Department of Radiology, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom; 2Clinical Pharmacology Unit, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom; 3GE Global Research, Niskayuna, NY, United States; 4The Australian School of Advanced Medicine, Macquarie University, Sydney, Australia Central pulse pressure (PP) is a major determinant of ventricular afterload which can be accurately measured only by means of invasive pressure measurements. In this work, we present a method based on Fourier velocity encoded M-mode and the cross-section-averaged flow equations to estimate the local PP in the aorta. The obtained results were found to be in good agreement with applanation tonometry performed in a cohort of 18 healthy volunteers (bias=1.25mmHg, 95% limits of agreement (LOA) = [-5.7,8.2]mmHg) and intravascular pressure measurements obtained in 4 patients undergoing diagnostic catheterization ((bias=-0.37mmHg, 95% LOA = [-9.2,8.4]). Hong Ye1, Gador Canton2, Xihai Zhao2, William Kerwin2, Chun Yuan2, Zhanming Fan1 1Department, Beijing Anzhen hospital, Capital Medical University, Beijing, China; 2Radiology, University of Washington, Seattle, WA, United States AAA rupture related risk factors include maximum diameter, wall stress or compliance, intraluminal thrombus (ILT), and calcification. The assessment of the correlations among these factors may improve the management and prognosis of AAA. This study investigated the association of wall compliance with ILT, calcification, and the size of infrarenal AAA using in vivo PC-MRA in 48 patients. We found the wall compliance was positively associated with ILT, which suggests thrombus may be a protective factor for AAA rupture. In addition, our results indicate that length to maximum diameter ratio may be a stronger indicator for wall compliance. Alain Lalande1,2, Clotilde Billard-Philip2, Marie Xavier1, Olivier Bouchot1,2, Eric Steinmetz2, Alexandre Cochet1, Paul Michael Walker1,2, Jean-Eric Wolf1,2, Franēois Brunotte1,2 1LE2I, University of Burgundy, Dijon, France; 2University Hospital of Dijon, Dijon, France Currently the evaluation of risk of rupture or dissection of the thoracic aorta is based on the aortic diameter, which is not a relevant parameter. To evaluate functional properties of the aorta, maximum blood flow velocity was evaluated in patients with well-classified diseases. 3D velocity imaging, acquired with velocity-encoded cine-MRI, and analysed with automatic post-processing allows the study of aortic blood flow. Compared with healthy subjects, the maximum blood flow velocity was higher for patients with bicuspid valve and lower for patients with the MYH11 mutation. There was no significant difference in patients with Marfan syndrome or annulo-aortic ectasia. 1349. Flow Sensitive 4D MRI at 1.5T and 3T Christoph Strecker1, Andreas Harloff2, Michael Markl3 1Department of Neurology, University Hospital, Albert-Ludwigs-University , Freiburg, Germany; 2Department of Neurology, University Hospital, Albert-Ludwigs-University , Freiburg , Germany; 3Department of Radiology, Medical Physics, University Hospital, Albert-Ludwigs-University , Freiburg, Germany Synopsis: It was the purpose of this study to evaluate the performance of flow-sensitive 4D MRI of the thoracic aorta at 1.5T and 3T. 10 healthy volunteers were examined with 4D-MRI at both field strengths with regard to velocity noise, 3D flow visualization and quantitative flow analysis. 3T was superior regarding reduced velocity noise, improved quality of blood flow visualization, and quantification of peak velocities. It could be shown that flow-sensitive 4D-MRI was feasible at both field strengths and can provide comprehensive information of aortic 3D hemodynamics and geometry. Gador Canton1, Jinnan Wang2, Li Dong1, William Sean Kerwin1, Chun Yuan1 1Radiology, University of Washington, Seattle, WA, United States; 2Clinical Sites Research Program, Philips Research North America, Briarcliff Manor, NY, United States The aim of this study was to determine the inter-scan reproducibility of distensibility measurements at the common and internal carotid arteries using CINE MRI at 3 T. Our results show a good agreement in the area and the distensibility measurements between the two scans. Furthermore, we compared the difference in distensibility for both segments of the artery. We found a significant difference between the common and internal carotid arteries, suggesting that mechanical modeling of the forces acting on the arterial wall could be further improved by incorporating the different mechanical properties of different arterial segments.
Larry Hernandez1, Andrew L. Wentland1,2, Erik T. Bieging2, Chris J. Francois2, Oliver Wieben1 1Medical Physics, University of Wisconsin, School of Medicine & Public Health, Madison, WI, United States; 2Radiology, University of Wisconsin, School of Medicine & Public Health, Madison, WI, United States While studies have shown that high wall shear stress (WSS) creates aneurysms and low WSS contributes to aneurysmal growth, the downstream effects of an aneurysm on WSS remain unknown. In this study we compared measurements of peak WSS in the descending aorta of volunteers and in patients with an ascending aortic aneurysm. Measurements of peak WSS were lower in patients than in normal volunteers; the percent increase in WSS from diastolic baseline to peak systole was greater in volunteers than in patients. The long-term effects of lower WSS in the patients require further investigation. 1352. Pressure Gradient Estimation from PC-MRI: Acceleration Versus Velocity Encoding Jelena Bock1, Felix Staehle1, Ramona Lorenz1, Kevin Michael Johnson2, Juergen Hennig1, Michael Markl1 1Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany; 2University of Wisconsin, Madison, United States MRI can be used to estimate blood pressure gradients non-invasively by solving the Navier-Stokes equation. Most applications use velocity encoded MRI data to calculate pressure gradients by deriving local acceleration based on spatial and temporal derivates of the measured velocities. To minimize noise propagation errors, acceleration encoded MRI can be used to directly measure flow acceleration. In this study in-vitro and in-vivo data were used to systematically evaluate the performance of acceleration and velocity encoding PC-MRI for pressure gradient estimation. Results indicate that data derived from acceleration encoded MRI are less noisy and may provide more reliable pressure difference estimation. 1353. Waveform Optimized (Easy to Build) Pulsatile Flow Phantom of the Common Carotid Artery Clemens Diwoky1, Christian Binter1, Johannes Konrad Strasser1, Rudolf Stollberger1 1Institute of Medical Engineering, Graz University of Technology, Graz, Austria A phantom simulating the exact flow-velocity pulse shape within the common carotid artery is proposed. Beside the exact representation of the flow profile attention is paid on keeping the system flexible, simple and inexpensive. Parameters of the used components are figured out in order to optimize and manipulate the final pulsatile flow. Andrew L. Wentland1,2, Erik T. Bieging2, Alex Frydrychowicz2, Thomas M. Grist1,2, Oliver Wieben1, Chris J. Francois2 1Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States; 2Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States While studies have shown that high wall shear stress (WSS) creates aneurysms and low WSS contributes to aneurysmal growth, the downstream effects of an aneurysm on WSS remain unknown. In this study we compared measurements of peak WSS in the descending aorta of volunteers and in patients with an ascending aortic aneurysm. Measurements of peak WSS were lower in patients than in normal volunteers; the percent increase in WSS from diastolic baseline to peak systole was greater in volunteers than in patients. The long-term effects of lower WSS in the patients require further investigation. 1355. MRI Measurements of Wall Shear Stress in the Infrarenal Aorta in the Young and Old Andrew L. Wentland1, Erik T. Bieging2, Alex Frydrychowicz2, Mark L. Schiebler2, Thomas M. Grist1, Oliver Wieben1, Chris J. Francois2 1Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States; 2Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States While studies have shown that low wall shear stress (WSS) contributes to the formation of atherosclerotic plaques and that low WSS correlates with high atherosclerotic indices, WSS in the elderly, who have a greater incidence of atherosclerosis, remains unknown. In this study, we compared measurements of peak WSS in the infrarenal aorta in young and old subjects. Measurements of peak WSS tended to be lower in the old than the young, although this trend was not statistically significant. The percent increase in WSS from diastolic baseline to peak systole was not significantly different between young and old subjects. Anas Dogui1, Nadjia Kachenoura2, Alain De Cesare2, Muriel Lefort1, Mourad Bensalah1,3, Alain Herment1, Boutouyrie Pierre4,5, Elie Mousseaux1,6 1INSERM U678 ,UPMC, Paris, France; 2INSERM U678,UPMC, Paris, France; 3Radiology department, APHP, European Hospital Georges Pompidou,, Paris, France; 4INSERM U970, Paris, France; 5Pharmacology department, APHP, European Hospital Georges Pompidou, Paris, France; 6Radiology department, APHP, European Hospital Georges Pompidou, Paris, France Aortic stiffness indices such as the local aortic deformability (AD) and the regional aortic pulse wave velocity (PWV) were assessed directly and non-invasively from morphological and hemodynamic magnetic resonance data on 40 subjects. The consistency of these indices was well described by a theoretical model derived from the Moens-Korteweg equation. A global aortic deformability (ADe) was estimated from PWV and carotid pulse pressure using the theoretical model and gave a similar description of stiffness of the ascending aorta as the local AD. 1357. Wall Shear Stress Analysis in Ascending Aortic Aneurysms Using PC VIPR Erik Tierney Bieging1, Benjamin R. Landgraf1, Alex Frydrychowicz1, Kevin M. Johnson2, Oliver Wieben, 12, Christopher J. Francois1 1Radiology, University of Wisconsin - Madison, Madison, WI, United States; 2Medical Physics, University of Wisconsin - Madison, Madison, WI, United States Wall shear stress (WSS) was analyzed in patients with ascending aortic aneurysms (AscAA) using phase-contrast MRI with 3D radial undersampling (PC VIPR), a 4D flow technique. Time resolved WSS was compared between patients with AscAA and healthy volunteers with normal aortic anatomy. Patients with AscAA were shown to have increased diastolic WSS, decreased WSS change over the cardiac cycle, and slower onset of systolic WSS. Additionally, spatial changes in WSS in AscAA were demonstrated. Marcus Carlsson1, Einar Heiberg1, Johannes Töger1, Karin Markenroth2, Freddy Ståhlberg3, Håkan Arheden1 1Clinical Physiology, Lund University Hospital, Lund, Skane, Sweden; 2Philips Medical Systems, Lund University Hospital, Lund, Skane, Sweden; 3Radiation Physics, Lund University Hospital, Lund, Skane, Sweden This study has demonstrated the feasibility of a new method for non-invasive quantification of biventricular kinetic energy using 4D phase contrast velocity encoded CMR. Three energy peaks of the LV and RV were seen in healthy subjects. Interestingly, the systolic energy was higher in the RV compared to the LV and in contrast the energy during early diastole was higher in the LV compared to the RV. 1359. A Novel MRI Framework for the Quantification of Any Moment of Arbitrary Velocity Distributions Petter Dyverfeldt1, Andreas Sigfridsson1, Hans Knutsson1, Tino Ebbers1 1Linköping University and Center for Medical Image Science and Visualization (CMIV), Linköping, Sweden Under the assumption that the intravoxel velocity distribution is symmetric about its mean, the well-known MRI phase-difference method permits an estimation of the mean velocity of a voxel. The mean velocity corresponds to the first moment of the velocity distribution. Here, a novel framework for the quantification of any moment of arbitrary spin velocity distributions is presented. Simulations on realistic velocity distributions demonstrate its application. The presented moment framework may assist in improving the understanding of existing MRI methods for the quantification of flow and motion and serve as a basis for the development of new methods. 1360. Is 2-D Velocity Encoded Cardiac MRI Accurate at 3T? Lindsay Marie Zeeb1, Jeffrey Kaye, Curtis E. Green1, Trevor J. Andrews, George Ernest Gentchos1 1Radiology, University of Vermont, Burlington, VT, United States 2-D Velocity encoded MRI (VEC-MRI) has not been widely validated at 3T field strength with regard to optimal imaging parameters and overall accuracy. In this study, 2D VEC-MRI at 3T was tested in vivo over a wide range of imaging parameters and compared to well validated cine functional volumes. VEC-MRI was highly accurate over a wide range of velocity encoded values, orientation of flow and at varying spatial resolution. This suggests that 2D VEC-MRI is highly accurate at 3T field strength and that further efforts to increase signal to noise or spatial resolution are probably not necessary compared to 1.5 T. 1361. 4D Blood Flow in the Left Heart Daniela Foell1, Steffen Taeger2, Bernd Jung3, Jelena Bock3, Philipp Blanke3, Christoph Bode2, Michael Markl3 1Cardiology , University Hospital , Freiburg, Germany; 2Cardiology, University Hospital, Freiburg, Germany; 3Diagnostic Radiology/Medical Physics, University Hospital, Freiburg, Germany Flow-sensitive 4D MRI was performed to visualize the complex blood flow in the left ventricle (LV), atrium and out-flow tract. Left atrial and LV vortex formation was seen in older and younger volunteers. The left pulmonary veins promote more pronounced vortexes in older and younger volunteers during systole and diastole. Intraventricular vortex formation was not different between older and younger individuals with most vortexes located in basal and midventricular parts of the LV. The knowledge of blood flow in the healthy heart is essential for further patient studies in cardiac disease such as LV aneurysms, valve insufficiencies or atrial arrhythmia. Erik Hedstrom1, Erik Bergvall1, Karin Markenroth Bloch2,3, Freddy Stahlberg4,5, Hakan Arheden1 1Cardiac MR Group, Department of Clinical Physiology, Lund University and Lund University Hospital, Lund, Sweden; 2MR department, Lund University Hospital, Lund, Sweden; 3Philips Medical Systems, Best, Netherlands; 4Department of Medical Radiation Physics, Lund University, Lund, Sweden; 5Department of Radiology, Lund University Hospital, Lund, Sweden AIM: We sought to determine whether the presence of contrast agent affects PC-CMR measurements of aortic blood flow, and myocardial displacement of the left ventricle in humans. METHODS: Velocity-encoded data was acquired pre and post contrast agent administration. RESULTS: Cardiac output differed -0.04±0.52 l/min and myocardial displacement 0.1±0.5mm. Magnitude image contrast for myocardial displacement was visually lower in the post contrast agent images. CONCLUSIONS: Acquisition of aortic flow is feasible both in the absence and presence of contrast agent. For myocardial displacement phase-contrast data is assessable as such, but delineation not possible post contrast agent administration due to lower image contrast. Juha Ilmari Peltonen1,2, Touko Kaasalainen3,4, Sari Kivistö3, Miia Holmström3, Kirsi Lauerma1 1HUS Medical Imaging Center, Helsinki University Central Hospital, Helsinki, Finland; 2Department of Biomedical Engineering and Computational Science, Aalto University, Helsinki, Finland; 3HUS Medical Imaging Center, Helsinki University Central Hospital, N/A, Helsinki, Finland; 4Department of Physics, Helsinki University, Helsinki, Finland 2D through plane phase contrast imaging of patients with stenotic pulmonal or aortic valves is subject to many sources of error. Accelerated flow speed increases the amount and range of the acceleration artefact near the valve. On the other hand, the nature of the flow becomes highly turbulent soon after the valve. In this study we have examined the effect of the mentioned error sources to measured net flow. Also, the optimal position of the measurement plane and clinical routine currently in use is discussed. 1364. Validation of 4D Left Ventricular Blood Flow Assessment Using Pathlines Jonatan Eriksson1, Petter Dyverfeldt1, Jan Engvall1, Ann F. Bolger2, Carl-Johan Carlhäll1, Tino Ebbers1 1Linköping University and Center for Medical Image Science and Visualization (CMIV), Linköping, Sweden; 2University of California San Francisco, San Francisco, CA, United States A validation study of a pathline based left ventricular (LV) blood flow quantification approach is presented. The approach integrates morphological and three-directional, three-dimensional cine phase-contrast MRI flow data, to separate the blood that transits the LV into four components. The validation includes comparison of the LV outflow obtained from this approach to results from clinically applied methods of determining LV outflow: 2D through-plane cine PC-MRI and Doppler ultrasound. Additionally inflow and outflow volumes obtained from the pathline based approach were compared.
Johannes Töger1,2, Johannes Ulén1,3, Marcus Carlsson1, Gustaf Söderlind2, Håkan Arheden1, Einar Heiberg1 1Cardiac MR Group, Department of Clinical Physiology, Lund University Hospital, Lund, Sweden; 2Numerical Analysis, Centre for Mathematical Sciences, Lund University, Lund, Sweden; 3Mathematical Imaging Group, Centre for Mathematical Sciences, Lund University, Lund, Sweden Blood flow patterns in the human heart are important for our understanding of cardiac pumping, and 4D phase contrast MRI may provide new insights. However, the flow is complex, making it hard to visualize and understand. In this work, the flow patterns in the left ventricle are interpreted using Lagrangian Coherent Structures, which reveal dynamically distinct compartments in the flow. Specifically, the inflow into the left ventricle is described in four healthy volunteers. 1366. Volumetric, 3D Velocity Encoded Valve Imaging with Radial Undersampling Steven R. Kecskemeti1, Kevin Johnson1, Oliver Wieben1 1Medical Physics, University of Wisconsin, Maidson, WI, United States The application of PC to cardiac valve imaging offers unique challenges. With the valve location changing as much as 30mm within the cardiac cycle, 2D single directional PC exams may miss the intended location. An attractive alternative is 3D PC covering a modest slab, with three directional velocity encoding [1]. However, current use is hampered by long scantimes necessary to achieve the high spatial and temporal resolution required for valve imaging. A 3D hybrid radial k-space acquisition allows both the mitral and tricuspid or the pulmonary and aortic valves to be imaged in a single scan within a reasonable time. Philip Anthony Hodnett1,2, Jeremy D. Collins3, Timothy Scanlon, Amir H. Davarpanah, Peter Weale4, Sven Zuehlsdorff4, James C. Carr, Chris Glielmi4 1Department of Cardiovascular Imaging, Northwestern University, Chicago, IL, United States; 2Northshore University HealthCare System, Chicago, IL, United States; 3Northwestern University, United States; 4Siemens Healthcare, MR Research and Development, Chicago, IL Background: Standard phase contrast MRI (PC-MRI) has potential sources for error when used in assessment of cardiac valvular pathology. We propose a new directionally independent tool for peak velocity evaluation Methods:The technique employs a phase contrast sequence with three flow encoding directions and one flow compensated reference. Phase difference images between between each flow encoded and the flow compensated images were quantified for directional velocity Results: The root sum of square of the 3D encoded data is computed inline and displayed in a magnitude of velocity dataset for each patient. We compared standard Throughplane phase contrast MRA and Inline calculation velocity of magnitude to the reference standard echocardiography. Conclusion:Extracting the magnitude of peak velocity independent of its direction significantly reduces error in peak velocity estimation (one-tailed t-test:p<0.02) 1368. In-Vitro Validation of Phase Contrast MRI in a Stenotic Phantom Under Steady Flow Using PIV Iman Khodarahmi1, Mostafa Shakeri, 12, Ron Pratt3, Janaka Wansapura3, Michael Keith Sharp2, Amir Arsham Amini1 1Department of Electrical and Computer Engineering, University of Louisville, Louisville, KY, United States; 2Department of Mechanical Engineering, University of Louisville, Louisville, KY, United States; 3Imaging Research Center, Cincinnati Childrens Hospital Medical Center, Cincinnati, OH, United States Phase Contrast MRI (PC-MRI) can be used to measure velocities in fluid flow using the phase mapping of the moving spins. Phase velocity mapping technique assumes that the velocity is constant over the echo time. This assumption is not valid for accelerating spins. In this study, we sought to evaluate the accuracy of PC-MRI velocity field in a severe stenotic phantom model, where the convective component of the acceleration is large. Considering the Particle Image Velocimetry (PIV) technique as the gold standard, we observed errors up to 26%, 16%, and 42% for pre-stenosis, at the stenosis, and post-stenosis regions, respectively. Jie Deng1, Christopher Glielmi2, Peter Weale2, Cynthia Rigsby1, Andrew deFreitas3, Sven Zuehlsdorff2 1Radiology, Children's Memorial Hospital, Chicago, IL, United States; 2Siemens Healthcare; 3Cardiology, Children's Memorial Hospital, Chicago, IL, United States Pediatric patients with congenital heart diseases often have irregular blood flow patterns (jet flow) with variant orientation and distributions. Phase contrast MRI with velocity encoding provides flow visualization and quantification of peak velocity within the core of jet flow. 2D slice oriented orthogonal to jet flow with through-plane velocity-encoding is commonly used in clinical studies. However, post-stenotic jets frequently exhibit a degree of eccentricity and can change direction throughout the cardiac cycle. Irregular and narrow jets can be more difficult to be measured. We propose inline computation of velocity magnitude independent of direction, eliminating reliance on optimal slice orientation and facilitating clinical evaluation of irregular flow patterns as found in stenotic jets.
1370. Validation of Distensibility Measurements from MRI-Based Pulse Wave Velocity Gabriel Acevedo-Bolton1, James Leung1, Chris Hardy2, Craig DeVincent, David Saloner1,3, Alison Meadows 1Radiology, UCSF, San Francisco, CA, United States; 2GE Global Research, Niskayuna, NY, United States; 3Radiology, VA Medical Center, San Francisco, CA A one-dimensional Fourier Velocity Encoded MRI method was used to measure the Pulse Wave Velocity in a series of elastic tubes with differing elasticity. The distensibility of these tubes was also measured using mechanical testing. Good correlation was found between the distensibility measured by mechanical testing methods compared to that estimated from the MR velocimetry technique. This study provides confidence that MRV is a useful technique for determining the Pulse Wave Velocity in compliant vessels and could be used for assessing differing stages of vascular disease. 1371. Analysis of Flow in Artificial Stenosis Models of Mid-Sized Arteries Using 3D PC-MRI Frank G. Zöllner1, Stefan Scheuer1,2, Erik Tumat1, Lothar R. Schad1 1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Chair for Applied Physics and Center for NanoScience, Ludwig-Maximilians-University Munich, Munich, Germany The aim of this work was to investigate whether 3D PC-MRI could be applied to support the grading of stenosis in med-sized arteries. Using a specially constructed flow phantom and a stenosis model with tube diameter of 8 mm and a stenosis of 50%, experiments at different flow rates (180 - 640 ml/s), slice thickness (1 4 mm), field strength (1.5 and 3.0 T) were performed. Results show that examinations should be performed at high field (3.0 T) and at flow rates up to 500 ml/min without hampering the measurements by areas of signal loss. 3D PC-MRI of mid-sized vessels with stenosis is feasible for certain flow rates. The presented results could be seen as guidance for in vivo situations to assess if an examination of a patient is reasonable in terms of outcome. Jonas Lantz1, Johan Renner1, Matts Karlsson1 1Department of Management and Engineering, Linköping University, Linköping, Sweden A method of incorporating MR-based imaging with advanced fluid-structure interaction simulations of the human aorta is presented. It is well established that wall shear stress is an indicator of increased risk for development of atherosclerotic plaques, and to be able to more accurately capture the flow (and solid) dynamics of the aorta, the movement of the wall is computed based on the blood flow. The geometries are extracted with a MRI scanner together with flow velocities, and used as boundary conditions in the simulations. The feasibility of the method is shown and initial results looks very promising. MRA Human/Clinical Studies Hall B Thursday 13:30-15:30 1373. Reduction of the RF Shielding Caused by a Vascular Stent Using a Pseudo-Adiabatic Excitation Guillaume Gilbert1, Gilles Beaudoin1 1Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada The use of a pseudo-adiabatic excitation pulse is investigated as a way to reduce the radiofrequency shielding caused by a vascular stent and consequently improve the depiction of the vessel lumen inside the stent. Using measurements performed on a vascular phantom, the employment of a pseudo-adiabatic excitation pulse is shown to allow the same effective flip angle to be simultaneously obtained inside and outside the stent, therefore eliminating the radiofrequency shielding effect of the stent during excitation. Andrew Nicholas Priest1, Martin John Graves1, David John Lomas1 1Radiology, Addenbrookes Hospital and University of Cambridge, Cambridge, United Kingdom Non-contrast-enhanced MR angiography methods can avoid the constraints associated with a short (first pass) acquisition window and concerns over contrast agent safety. A recently demonstrated method uses a modified motion-sensitised driven equilibrium (MSDE) preparation to controllably suppress flowing blood. Vascular images are generated by subtraction of bright- and dark-blood images, obtained without and with flow suppression. This work demonstrates a series of modifications to improve image quality and background suppression, and evaluates the technical performance of the resulting method in the peripheral vasculature of 8 volunteers. Excellent image quality was obtained in all arteries, except for some popliteals. Gurpreet Singh Sandhu1,2, Daniel P. Hsu1, Joan Tamburro3, Mark A. Griswold1, Vikas Gulani1,2 1Radiology, University Hospitals of Cleveland, Case Western Reserve University, Cleveland, OH, United States; 2Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States; 3Dermatology, University Hospitals of Cleveland, Case Western Reserve University, Cleveland, OH, United States Digital subtraction angiography is considered the gold standard imaging technique for diagnosis and monitoring of pediatric peripheral vascular lesions since in addition to providing information regarding blood supply to the lesion, it also provides an option for therapeutic embolization. Unfortunately, this technique is an invasive procedure requiring induction of general anesthesia, iodinated contrast material, ionizing radiation exposure and small albeit definable risk of potentially life-threatening complications. Here, we evaluate the efficacy of time-resolved MRA for evaluation of suspected peripheral vascular lesions in infants and young children. 1376. High Temporal and Spatial Resolution 3D CE-MRA of the Whole Brain Clifton R. Haider1, Josh Damon Trzasko1, Eric A. Borisch1, Norbert G. Campeau1, Petrice M. Mostardi1, John Huston1, Armando Manduca1, Stephen J. Riederer1 1Radiology, Mayo Clinic, Rochester, MN, United States The purpose of this work is to demonstrate the implementation of a dynamic MRA technique using 12x 2D SENSE accelerated Cartesian Acquisition with Projection-Reconstruction-like sampling for angiographic imaging of the brain, with 1 sec frame time and 3 sec temporal footprint, sufficient to resolve arterio-venous transit of cerebral blood flow. Additional post-processing with a non-convex compressive sensing reconstruction is also presented, resulting in further improvement of angiographic image quality, from removal of non-uniform noise amplification. 1377. T1 Contrast of MPRAGE in Carotid Plaque Imaging Yiu-Cho Chung1, Michael Jerosch-Herold2, Ravi T. Seethamraju3, Peter Libby4, Marcelo Di Carli5, Raymond Kwong6 1Siemens Medical Solutions USA, Inc., Columbus, OH, United States; 2Radiology, Brigham and Women's Hospital, MA, United States; 3Siemens Medical Solutions USA, Inc., MA, United States; 4Cardiovascular Medicine, Brigham and Women's Hospital, MA, United States; 5Nuclear Medicine, Brigham and Women's Hospital, MA, United States; 6Cardiovascular Imaging, Brigham and Women's Hospital, MA, United States MPRAGE has excellent T1 contrast and is useful for thrombus imaging. Though blood is usually suppressed in vessel wall imaging, nonzero blood signal may be useful in depicting blood and vessel wall. By setting TI longer than the blood null time, MPRAGE can provide good contrast between blood and vessel wall due to their intrinsic T1 difference. In a small patient cohort, we used such approach for MPRAGE, and compared the images with T2w-SPACE. We found that the grey blood MPRAGE can provide information about the plaque and lumen that was not obvious in dark blood images. 1378. Common Artifacts of Pulmonary Artery MRA and Potential Solutions Scott K. Nagle1,2, Mark L. Schiebler1, Christopher J. Francois1, Thomas M. Grist1, Scott B. Reeder1,3 1Radiology, University of Wisconsin, Madison, WI, United States; 2Radiology, Wm. S. Middleton Veterans Affairs (VA) Hospital, Madison, WI, United States; 3Medical Physics, University of Wisconsin, Madison, WI, United States Contrast-enhanced MRA has been clinically accepted at our institution as a useful alternative to CTA for the diagnosis of pulmonary embolism, particularly in young patients where radiation dose reduction is a high priority. This increasing utilization has led to the need to understand and mitigate artifacts that are unique to MRA, increasing the diagnostic accuracy of these scans. Based upon our experience interpreting approximately 200 clinical cases, we have identified and provided potential solutions to two common artifacts that are unique to MRA. Arie Simon Bode1,2, Robrecht Nils Planken3, Bastiaan Versluis1, Joachim E. Wildberger1,4, Jan H. Tordoir2,5, Tim Leiner1,5 1Radiology, Maastricht University Medical Center, Maastricht, Netherlands; 2Surgery, Maastricht University Medical Center, Maastricht, Netherlands; 3Radiology, Academic Medical Center, Amsterdam, Netherlands; 4Cardiovascular Research Institute Maastricht, Maastricht, , Netherlands; 5Cardiovascular Research Institute Maastricht, Maastricht, Netherlands Knowledge of upper extremity vascular geometry prior to dialysis access creation improves clinical outcome. Purpose of the present study was to compare a non-contrast enhanced (NCE) balanced TFE sequence with the current standard of reference, CE-MRA. In 10 healthy volunteers and 5 patients with ESRD we obtained both NCE-bTFE and CE-MRA images. Although CE-MRA was superior for arterial depiction NCE-bTFE yielded images of diagnostic quality in the vast majority of subjects. Furthermore, NCE-bTFE enabled visualization of significantly more venous segments compared compared to CE-MRA. bTFE proved to be an attractive alternative for pre-operative vascular mapping prior to vascular access creation. Gunther Schneider1, Mieczyslaw Pasowicz2, Josef Vymazal3, Zdenek Seidl4, Manuela Aschauer5, Deniz Bilecen6, Roberto Iezzi7, Claudio E M Ballarati8 1Radiology, University Hospital Hamburg, Hamburg/Saar, Germany; 2Diagnostics and Rehabilitation, John Paul II Hospital, Krakow, Poland; 3Radiology, Na Homolce Hospital, Prague, Czech Republic; 4Radiology, Lékarskį Fakulta Neurologicka Klinika, Prague, Czech Republic; 5Medical University of Graz, Graz, Austria; 6Radiology, University Hospital Basel, Switzerland; 7Radiology, Universitą G. D'Annunzio, Chieti, Italy; 8Radiology, Hospital Valduce, Como, Italy In a prospective comparison of the efficacy and safety of gadobenate dimeglumine vs the intravascular blood pool agent gadofosveset trisodium for contrast-enhanced MR angiography (CE-MRA) of the renal arteries in 38 subjects, blinded experts consistently found first-pass CE-MRA after gadobenate dimeglumine to be superior to CE-MRA after gadofosveset in terms of sensitivity, specificity, accuracy, PPV, and NPV. Steady state images obtained following gadofosveset administration provided no additional diagnostic benefit in this study. Timothy Leiner1, Suzanne C. Gerretsen2, Thierry le Maire2, Stephan Miller3, Siegfried Thurnher4, Christoph U. Herborn5, Henrik J. Michaely6, Harald Kramer7, Angelo Vanzulli8, Josef Vymazal9, Martin Wasser10 1Radiology, Maastricht University Hospital, Maastrict, Netherlands; 2Radiology, Catharina Hospital, Eindhoven, Netherlands; 3Radiology, Eberhard-Karls University, Tübingen, Germany; 4Radiology, Hospital of St. John of God, Vienna, Austria; 5Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; 6Institute of Clinical Radiology, University Hospital Mannheim, Mannheim, Germany; 7Radiology, Ludwig Maximilians University, Munich, Germany; 8Hospital Niguarda Ca Granda, Milan, Italy; 9Radiology, Na Homolce Hospital, Prague, Czech Republic; 10Radiology, Leiden University Medical Center, Leiden, Netherlands Equivalent 0.1 mmol/kg doses of gadobenate dimeglumine and gadopentetate dimeglumine were compared in terms of diagnostic performance in 397 segments from 96 patients with suspected peripheral arterial occlusive disease undergoing CE-MRA, using DSA as the reference standard. Three blinded readers rated the diagnostic performance of gadobenate dimeglumine significantly better in terms of sensitivity, specificity, and overall accuracy. In addition, significantly higher PPV and NPV values were noted after gadobenate dimeglumine compared to gadopentetate dimeglumine, despite the equivalent dose. Yasuo Takehara1, Haruo Isoda2, Shuhei Yamashita2, Mika Kamiya2, Naoki Unno3, Hiroyasu Takeda1, Masaya Hirano4, Marcus T. Alley5, Roland Bammer5, Takashi Kosugi6, Yasuhide Ohkura6, Harumi Sakahara 1Radiology, Hamamatsu Univ. Hospital, Hamamatsu, Shizuoka, Japan; 2Radiology, Hamamatsu Univ. School of Medicine, Hamamatsu, Shizuoka, Japan; 3Vascular Surgery, Hamamatsu Univ. School of Medicine; 4GE Healthcare, Hino, Tokyo, Japan; 5Radiology, Stanford Univ.; 6R's Tech Co. Ltd. Combined use of time-resolved 3 dimensional phase contrast MRA (4D-flow) and flow analysis software was useful in planning the catheter and surgical intervention for the aneurismal dilation of the splanchnic arteries. The method identified the significant alteration in the flow dynamics in splanchnic arteries mostly due to celiac artery stenosis (73 %). Measured WSS of the segment of aneurismal wall was significantly lower ( < 1.5 Pa) than normal segments, which may be reflecting that the aneurismal wall is continuously affected by the growing risk of rupture. James H. Holmes1, Kang Wang2, Reed F. Busse1, Christopher J. Francois3, Philip J. Beatty4, Lauren A. Keith2, Yijing Wu2, Scott B. Reeder3, Jean H. Brittain1, Frank R. Korosec3 1Applied Science Laboratory, GE Healthcare, Madison, WI, United States; 2Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States; 4Applied Science Laboratory, GE Healthcare, Menlo Park, CA A method combining an interleaved variable density (IVD) Cartesian acquisition with a reconstruction that integrates HYPR and parallel imaging is applied to peripheral run-off MRA. The method is compared to conventional view sharing in normal volunteers, demonstrating improved spatial resolution and temporal fidelity. Preliminary clinical results in patients with peripheral vascular disease are also presented. 1384. Quiescent Interval Single Shot MR Angiography Robert R. Edelman1, John Sheehan1, Eugene Dunkle1, James Carr2, Christopher Glielmi3, Xiaoming Bi3, Ioannis Koktzoglou1 1Radiology, NorthShore University HealthSystem, Evanston, IL, United States; 2Northwestern University; 3Siemens Healthcare Quiescent interval single shot (QISS) MRA uses an ECG-triggered, fat suppressed, 2D balanced SSFP sequence incorporating slice-selective saturation and a quiescent interval for maximal inflow enhancement. Following optimization at 1.5 Tesla, a pilot study was performed in patients with peripheral vascular disease (PVD) using contrast-enhanced MRA as the reference standard. The sensitivity, specificity, positive and negative predictive values of QISS for significant stenosis or occlusion were 92.2%, 94.9%, 83.9% and 97.7%. In conclusion, QISS provided robust depiction of normal peripheral arterial anatomy and PVD in less than 10 minutes without the need to tailor the technique for individual patients. Atsushi Ono1,2, Kenya Murase1, Toshitaka Taniguchi3, Osamu Shibutani4, Satoru Takata2, Yasuyuki Kobashi2, Yusuke Hashiguchi2, Mitsue Miyazaki5,6 1Medical Physics and Engineering, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan; 2Medical Technology, Kousei Hospital, Okayama, Japan; 3Kawasaki Medical School Kawasaki Hospital, Okayama, Japan; 4Kurashiki Riverside Hospital, Kurashiki, Okayama, Japan; 5Toshiba Medical Research Institute, Vernon Hills, IL, United States; 6Toshiba Medical Systems Corp, Otawara, Tochigi, Japan The diagnostic accuracy of non-contrast-enhanced MR venography using both the flow-refocused fresh-blood imaging (FR-FBI) and the swap phase-encode arterial double-subtraction elimination (SPADE) techniques for detecting deep vein thrombosis (DVT) were prospectively assessed and compared using conventional X-ray venography as the reference standard. Thirty-two consecutive patients suspected of having DVT, examined using conventional X-ray venography, underwent MR FR-FBI and SPADE. Two radiologists independently assessed the non-contrast MR venograms for presence and the sensitivities for diagnosing thrombus were 100% for both reviewers. The specificities were 100% and 99.6% and the interobserver agreement was almost perfect (Č = 0.92). 1386. Aortic Compliance in Normals Correlates with Age and BMI Yi Wang1,2, Edwin Estrada1, Simcha Pollack1, Visali Kodali1, Nathaniel Reichek1,2 1Research and Education, St. Francis Hospital, Roslyn, NY, United States; 2Biomedical Enginnering, State University of New York, Stony Brook, NY, United States Aortic compliance (AC) can be evaluated noninvasively and its reduction with age in normals has been demonstrated with MRI. Decreased aortic compliance (AC) is associated with aging, systolic hypertension and left ventricular diastolic dysfunction. Aortic pulse wave velocity (PWV) often serves as a surrogate to AC, and it can be evaluated using a single breath-hold phase contrast imaging technique. Its age correlation has been demonstrated by both MR and echo studies in normal volunteers. We evaluated the aortic compliance and their relationship to age, as well as the other biomedical parameters in 189 normal volunteers. 1387. Comparison of High Spatial Resolution Time-Resolved 3D Contrast-Enhanced MR Angiography Phillip Matthew Young1, James F. Glockner1, Clifton R. Haider1, Petrice M. Mostardi1, Terri J. Vrtiska1, Thanila A. Macedo1, Stephen J. Riederer1 1Diagnostic Radiology, Mayo Clinic, Rochester, MN, United States 10 patients were imaged using both CTA and high-resolution time-resolved MRA and images were compared for evaluation of below the knee arterial runoff. Although the study population is skewed because some patients were referred for MRA because of nondiagnostic CTA, MRA was not limited by calcification, inadequate arterial opacification, or venous contamination, all of which were problematic with CTA. Although SENSE reconstruction artifact was apparent on the MRA images, it did not interfere with image interpretation. Additionally, the time-resolved dataset acquired with MRA provided additional information about flow and perfusion which was not apparent with the CTA dataset. Yasuo Amano1, Ryo Takagi1, Yuriko Suzuki2, Testuro Sekine1, Yoshio Matsumura1, Katsuya Takahama1, Shinichiro Kumita1, Van Cauteren Marc2 1Radiology, Nippon Medical School, Tokyo, Japan; 2Philips Electronics Japan, Tokyo, Japan Non-contrast-enhanced 3D MRA acquired by turbo spin-echo or steady-state free precession depict thoracic aortic dissection, but it lacks in the flow information at the entry, ulcer-like projection, and true and false lumen. Time-resolved 3D flow tracking generated from 3D phase-contrast imaging provided the blood flow data and visualized the streamline or velocity vector in aortic dissection. The combination of unenhanced 3D MRA and time-resolved 3D flow tracking may be useful for the comprehensive evaluation of the thoracic aortic dissection. 1389. MPRAGE Detection of Hemorrhage in Carotid Plaque Joseph Scott McNally1, Seong-Eun Kim2, John Roberts2, Daniel Nightingale3, Laura K. Findeiss, Gerald S. Treiman4, Dennis L. Parker2 1Radiology, University of Utah, Salt Lake City, UT, United States; 2UCAIR, University of Utah; 3Pathology, VA Salt Lake City Health Care System; 4Surgery, VA Salt Lake City Health Care System Plaque hemorrhage may discriminate an unstable plaque from a more stable lesion. Patients scheduled for carotid endarterectomy underwent MR imaging with 3D MPRAGE (Magnetization-prepared rapid acquisition with gradient-echo), 3D TOF, 2D DIR T1 and T2 sequences. After carotid endarterectomy, plaque components were identified. MPRAGE hyperintensity correlates with hemorrhage on histology. Variable ages of blood products were detected by the MPRAGE sequence, ranging from recent to remote. Hemorrhage was discriminated from lipid, necrosis, collagen, and calcification using the MPRAGE sequence. This sequence may play an important role in determining which patients benefit from medical management as opposed to surgical intervention. 1390. Benefits and Pitfalls in the Use of Contrast Agents in 4D Flow Imaging Michael Loecher1, Christopher Francois2, Kevin Johnson1, Darren Lum2, Oliver Wieben1,2 1Department of Medical Physics, University of Wisconsin, Madison, WI, United States; 2Department of Radiology, University of Wisconsin, Madison, WI, United States This study aims to determine the effects of residual contrast agent on radially encoded flow sensitive MR scan quality for cardiac and renal MRI. Examination of vessel signal and diagnostic quality of the vasculature suggests significant improvement in vessel visualization following contrast administration in most vessels. This improvement in vessel conspicuity was not seen in the renal arteries, where segmental vessel visualization was reduced, which we hypothesize is due to decreased contrast from accumulation of the agent in the renal parenchyma. Tobias Saam1, Thomas Pfefferkorn2, Maximilian Habs1, Marcus Hacker3, Axel Rominger3, Clemens C. Cyran1, Martin Dichgans2, Maximilian F. Reiser1, Konstantin Nikolaou1 1Clinical Radiology, University of Munich, Munich, Bavaria, Germany; 2Neurology, University of Munich, Munich, Bavaria, Germany; 3Nuclear Medicine, University of Munich, Munich, Bavaria, Germany Spontaneous cervical artery dissection (sCAD) is a frequent cause of ischemic stroke in young adults. The pathogenesis of sCAD is poorly understood. The aim of this study was to use PET/CT and MRI to estimate the prevalence of perivascular inflammation in sCAD. This study demonstrates that inflammatory changes at the site of the arterial dissection are common in sCAD patients. In a subset of these patients, perivascular inflammation was not confined to the site of the dissection, suggesting that vessel wall inflammation might play a role in the pathogenesis of sCAD. Masaaki Akahane1, Jiro Sato1, Izuru Matsuda1, Shuhei Komatsu1, Yasushi Watanabe2, Yoshiro Satake2, Naoyuki Takei3, Kuni Ohtomo1 1Radiology, University of Tokyo, Bunkyo-ku, Tokyo, Japan; 2Clinical Radiology, University of Tokyo, Bunkyo-ku, Tokyo, Japan; 3Japan Applied Science Laboratory, GE Healthcare Japan, Hino-shi, Tokyo, Japan Nonenhanced spin-labeling MRA at 3.0 T is promising because of improved signal-to-noise ratio, but the influence of changes in relaxation times and field inhomogeneity on the image quality should be assessed. Eighteen volunteers underwent nonenhanced spin-labeling MRA using respiratory-gated balanced steady state free precession sequence with both Signa HDx 1.5-T and Signa HDx 3.0-T scanners (GE Healthcare, Milwaukee, WI). Contrast between PHA and the liver parenchyma was significantly higher at 3.0 T than 1.5 T. Fat suppression was more homogeneous at 1.5 T. Major anatomical variations were able to be evaluated sufficiently on both 3.0-T and 1.5-T images. 1393. Effect of Flip Angle on Volume Flow Measurement with Non-Triggered Phase-Contrast MR Hisashi Tanaka1, Norihiko Fujita, Kenya Murase 1Radiology, Osaka University, Suita, Osaka, Japan Volume flow rates of the bilateral internal carotid artery and the basilar artery were measured with cine and non-triggered phase-contrast MR imaging. For non-triggered phase-contrast imaging, flip angles of 4, 15, 60 and 90 were used for 40 volunteers and of 8, 15 and 30 for 54 volunteers. The ratio of volume flow rate obtained with non-triggered phase-contrast imaging to that obtained with cine phase-contrast imaging significantly increases with an increase in the flip angle. The mean ratios lie within a relatively narrow range of +/- 15 % with a wide range of flip angles of 8 to 90. Dariusch Reza Hadizadeh1, Guido Matthias Kukuk1, Marius Kaschner1, Carsten Meyer1, Kai Wilhelm1, Arne Koscielny2, Frauke Verrel2, Jürgen Gieseke1, Hans Heinz Schild1, Winfried Albert Willinek1 1Radiology, University of Bonn, Bonn, NRW, Germany; 2Vascular surgery, University of Bonn, Bonn, NRW, Germany The blood pool contrast agent (BPCA) gadofosveset trisodium provides high vessel-to-background contrast during a prolonged imaging time window. 125 µm³ high spatial resolution 3DMRA (HRMRA) at 1.5T was acquired with the quadrature body coil only after application of the BPCA in 7 patients who suffered from peripheral arterial occlusive disease. Stenosis grading was compared to DSA. Overall image quality was rated diagnostic in all patients and stenosis grading in HRMRA matched with that in DSA in all patients. HRMRA provided high SNR and CNR in arterial and venous vessels. 125 µm³ HRMRA is feasible using a quadrature body coil only. 1395. Hybrid Calf Magnetic Resonance Angiography Using a Time Resolved Technique Jeremy Douglas Collins1, Philip Hodnett1, Timothy Scanlon1, Sven Zuehlsdorff2, James Carr1 1Radiology, Northwestern University, Chicago, IL, United States; 2Siemens Healthcare, MR Research and Development Evaluation of a hybrid magnetic resonance angiography in a patient cohort using a low-dose time-resolved sequence along with a conventional bolus-chase technique. Despite a lower spatial resolution, the time-resolved sequence achieved a high accuracy for stenosis compared to the reference standard bolus-chase examination, with clear separation of the arterial and venous phases of vascular filling in 95% of patients and identification of retrograde filling. This hybrid technique enables assessment of potential target vessels with an average supplemental gadolinium dose of 0.04 mmol/kg and has become the clinical standard at our institution. 1396. Fresh Blood Imaging Versus Contrast Enhanced MRA with DSA as the Reference Standard Rakesh K. Puni1, M J. Henderson1, Lowri Morus1, C Green1, Faiza Admiraa-Behloul2, S Roy-Choudhury1 1Heart of England NHS Foundation Trust, Birmingham, United Kingdom; 2MR-BU, Toshiba Meidcal Systems Europe, Zoetermeer, Netherlands With Nephrogenic systemic fibrosis (NSF) receiving considerable attention, non-contrast enhanced (NCE) MRA appears to be a feasible alternative to contrast enhanced (CE) MRA. Fresh Blood Imaging (FBI) is a NCE technique that was introduced in late 90s by M Miyazaki and co-workers, and has gained popularity only very recently after the NSF-Gadolinium link has been reported in patients with impaired renal function. The purpose of this pilot study was to compare FBI technique to CE-MRA using DSA as the reference standard. 1397. Non-Contrast-Enhanced Whole-Body MR Angiography Katsumi Nakamura1, Akiyoshi Yamamoto1, Riichiro Nagashima1, Kentaro Haraoka1, Mitsue Miyazaki2 1Radiology, Tobata Kyoritsu Hospital, Kitakyushu, Fukuoka, Japan; 2Toshiba Medical Research Institute, USA, Vernon Hills, IL, United States Non-enhanced whole-body MRA combined with several optimized non-enhanced MRA methods appears to be an optimal and non invasive approach to systemic arterial imaging. 1398. Navigator-Gated Quiescent Interval Single Shot for Pelvic MR Angiography Christopher Glielmi1, Xiaoming Bi1, Ioannis Koktzoglou2, Philip Hodnett3, Sven Zuehlsdorff1, Robert R. Edelman2 1Cardivascular MR R&D, Siemens Healthcare, Chicago, IL, United States; 2Radiology, NorthShore University HealthSystem, Evanston, IL, United States; 3Radiology, Northwestern University, Chicago, IL, United States Quiescent Interval Single Shot (QISS) is a promising new method for non-contrast magnetic resonance angiography (MRA) with high diagnostic potential. However, respiratory motion can cause stair-step artifacts in some regions including the iliac arteries. In this study, we present navigator-gated QISS which gates the data acquisition based on diaphragm position to minimize respiratory artifacts. Our approach provides image quality consistently comparable to breath-holding with absence of respiratory artifacts seen in standard free breathing approaches. We recommend navigator-gated QISS as a free breathing alternative to breath-holding, further improving the diagnostic quality of QISS. Qi Liu1, Ping jian Lu1, Fei Wang1, li Wang1 1Radiology, Changhai Hospital, Second Military Medical University, Shanghai, China 3D CE-MRA can determine the type of dissection; display the true and false lumina, intimal flap, location and size of the initial entry and its relationship with the neighboring arterial orifice, and presence and amount of thrombus in false lumen. These data are important for the planning of surgical and endovascular therapy. Furthermore, it does not require iodinated contrast material, is radiation free, and has low morbidity. It combines the advantages of arterial angiography with those of MR imaging and, unlike CT angiography, does not require the removal of bone structures for adequate visualization of the vasculature. Jie Jane Cao1,2, Yi Wang, Jeannette McLaughlin, Michael Passick, Nathaniel Reichek 1St Francis Hospital, Roslyn, NY, United States; 2State University of New York at Stony Brook, Stony Brook, NY, United States We developed a 2D dynamic acquisition to measure pulmonary transit time in normals and heart failure patients and investigated the impact of temporal resolution on pulmonary transit time measurement. 1401. Non-Contrast MR Angiography of the Toes: Correlations with Age and Gender Jun Isogai1, Mitsue Miyazaki2, Hideo Hatakeyama1, Takeshi Shimada1, Takashi Yamada1, Tomoko Miyata3, Kenji Yodo3, Ken Kudou3 1Radiology, Hasuda Hospital, Hasuda, Saitama, Japan; 2Toshiba Medical Research Institute USA, United States; 3Toshiba Medical Systems Corp., Japan Visualization of toe arteries is quite difficult using conventional nonenhanced MR angiography, such as time-of-flight due to the tortuous arterial trees and slow-velocity, especially in older female toes. Gadolinium-enhanced MRA also has several problems with injection rates, the amount of contrast material, and the separation of arteries from veins. Due to the recent concerns of Gadolinium-related Nephrogenic Systemic Fibrosis (NSF), nonenhanced MRA solutions have gained interest. Depiction of small arteries of the toes was investigated using time-spatial labeling inversion pulse (time-SLIP) in combination with a swap phase encode extended data (SPEED) acquisition. 1402. Fat Saturation Techniques in Non-Contrast Enhanced B-SSFP MRA of the Renal Arteries. Anne Dorte Blankholm1, Won Yong Kim2,3, Brian Stausbųl-Grųn1, Michael Pedersen4, Steffen Ringgaard4 1MR-Centre, Dept. of Diagnostic Imaging, Århus University Hospital, Skejby, Århus N, Denmark; 2MR-Centre, , Århus University Hospital, Skejby, Århus N, Denmark; 3Department of Cardiology, Århus University Hospital, Skejby, Århus N, Denmark; 4MR-Centre, Århus University Hospital, Skejby, Århus N, Denmark Due to the risk for inducing nephrogenic systemic fibrosis (NSF) there is a need for developing angiography without the use of contrast agents, in particular for patients with renal disease. MRA of the renal arteries was obtained using a balanced steady-state-free-precession (B-SSFP) method with a slab selective inversion prepulse in combination with ProSet, SPAIR and SPIR fat saturation and the images were compared with respect to fat suppression and CNR. The ProSet technique (water selective excitation with binomial pulses) were most effective for fat saturation and produced highest vessel/muscle CNR using this sequence.
Jun Isogai1, Mitsue Miyazaki2, Takeshi Shimada1, Hideo Hatakeyama1, Takashi Yamada1, Tomoko Miyata3, Kenji Yodo3, Ken Kudou3 1Radiology, Hasuda Hospital, Hasuda, Saitama, Japan; 2Toshiba Medical Research Institute USA, United States; 3Toshiba Medical Systems Corp., Japan Visualization of the subclavian arterial branches is quite difficult using conventional nonenhanced time-of-flight MR angiography due to the tortuous arterial trees and small vessels. Gadolinium-enhanced MRA also has several problems with injection rates, the amount of contrast material, and venous superimposition. Due to the recent concerns of Gadolinium-related Nephrogenic Systemic Fibrosis (NSF), nonenhanced MRA solutions have gained interest. Visualization of small arteries of the subclavian arterial branches was investigated using 3D half-Fourier FSE images combined with time-spatial labeling inversion pulse (time-SLIP). J A. Clavero1, Mitsue Miyazaki2, Faiza Admiraa-Behloul3, X Alomar1, J Masia4, G Pons4 1Diagnostic Imaging, Clinica Creu Blanca, Barcelona, Spain; 2Toshiba Medical Research Institute, Vernon Hills, United States; 3Toshiba Medical Systems Europe, Zoetermeer, Netherlands; 4Plastic Surgery, Free University of Barcelona, Barcelona, Spain Post-mastectomy autologous breast reconstruction using abdominal perforator flaps gained popularity because it offers a natural soft breast mound, and preserves the donor site muscle and function. Because the vascular anatomy of the abdominal wall is highly variable between individuals, a detailed accurate preoperative vascular map of the abdomen can significantly reduce the operating time, with a better surgical outcome. MDCTA proved to be very useful for this purpose [1], however it requires ionizing contrast agents and radiation. the purpose of this work was to investigate the role of non-contrast enhanced MR angiography (NC-MRA), as compared to MDCTA, in the preoperative evaluation of the vascular anatomy of the abdominal wall for abdominal perforator flap surgery in post-mastectomy breast reconstruction. Johannes T. Heverhagen1, Sabrina El Tobgui, Mykhylo Burbelko, Klaus J. Klose 1Department of Diagnostic Radiology, Philipps University, Marburg, Germany The purpose of this study was to intraindividually compare static, high resolution and dynamic CE MRA of the lower legs in patients with severe peripheral arterial occlusive disease (PAOD). State of the art 4D MRA of the lower legs for suspected PAOD provides excellent image quality without venous overlay, an artefact that severely influences diagnostic quality in static MRAs. It is user independent proven by a CohenĀ“s kappa of 0.92. 4D MRA of the lower legs should be employed in all patients undergoing CE MRA for suspected PAOD. Jiang Lin1, Dan li2, Fu-hua Yan2, Jiang-hua Wang2 1Radiology, Shanghai zhongshan hospital, Shanghai, China; 2shanghai zhongshan hospital Takayasu Arteritis is a systemic disorder which mainly involves medium- and large-sized arteries. As it progresses, many kinds of luminal pathology may appear, such as stenosis, occlusion and aneurysm. However, at an early stage, the vessel lumen often remains unchanged while inflammation or thickening of the vessel wall may already exist. Furthermore when the disease is active, the mural tissue may be avidly enhanced. Early diagnosis and comprehensive assessment of its severity and activity are required which may influence treatment procedure and outcome. In this study we explored the potential of Whole-body MRA for comprehensive diagnosis of Takayasu Arteritis with postcontast vessel wall imaging. Giles Roditi1, Douglas Orr2 1Radiology, Glasgow Royal Infirmary, Glasgow, Scotland, United Kingdom; 2Vascular Surgery, Glasgow Royal Infirmary, Glasgow, Scotland, United Kingdom Patients for bypass grafting need vein suitability assessed. High resolution blood pool contrast agent imaging compared to ultrasound in 20 patients with gadofosveset for MRA. Deep veins assessed for patency, quality & calibre. Vein diameters assessed as similar calibre. MRA showed more veins, divisions and perforating tributaries. MRI studies judged more informative than the descriptive ultrasound reports except for one patient with poor image quality due to severe pain during scan. Lower limb MRA performed with blood pool contrast agent and steady state imaging may obviate additional ultrasound examination in assessment for potential bypass grafting. Challenge to ensure consistent image quality. 1408. Combined Renal and Peripheral MRA with a New Technique at 3.0 T Philip Anthony Hodnett1, Ioannis Koktzoglou2, John Sheehan2,3, Amir Davarpanah3, Christopher Glielmi4, Robert Edelman2 1Radiology, Northwestern Memorial Hospital, Chicago, IL, United States; 2Northshore University Healthcare System; 3Northwestern University; 4Siemens Healthcare, MR Research and Develpoment, Chicago, IL Introduction: The proliferation and increased use of 3.0 T MR Systems offers both potential advantages and difficulties in the implementation of unenhanced MRA techniques. Materials and Methods: To perform an initial feasibility study followed by technical optimization of quiescent interval single shot (QISS) magnetic resonance angiography for renal artery and lower extremity evaluation. The study was performed with IRB approval. Seven healthy volunteers underwent combined unenhanced Renal and Peripheral Lower Limb Angiography Conclusion: We report the feasibility of the QISS technique as a potential MRA technique for combined dual Renal and Lower extremity unenhanced MRA at 3.0 T MRA Preclinical Technical Development Hall B Monday 14:00-16:00 1409. Black-Blood Restricted Field of View Sequence for Pre-Ablation Imaging of the Atria Christian Stehning1, Dennis Caulfield2, Benjamin R. Knowles2, Steffen Weiss1, Tobias Schaeffter2 1Philips Research Europe, Hamburg, Germany; 2Division of Imaging Sciences, King's College, London, United Kingdom Knowledge of the atrial wall anatomy is important for the subsequent RF ablation procedure. A restricted FOV MR sequence which allows exclusive imaging of the atria was evaluated in the present study. It provides a clear depiction of the atrial wall thickness with submillimeter resolution in a clinically acceptable scan time and mitigates motion artifacts, particularly in patients with cardiac arrhythmia. Zhaoyang Fan1,2, Xiaoming Bi3, Xiangzhi Zhou1, Sven Zuehlsdorff3, Rohan Dharmakumar1, James Carr1, Debiao Li1,2 1Radiology, Northwestern University, Chicago, IL, United States; 2Biomedical Engineering, Northwestern University, Evanston, IL, United States; 3Cardiac MR R&D, Siemens Healthcare, Chicago, IL, United States A noncontrast MRA technique using ECG-triggered 3D balanced SSFP with flow-sensitive dephasing (FSD) preparation has recently been validated in the distal lower extremities of healthy volunteers. The FSDs first-order gradient moment, m1, is shown to be the most important parameter to determine angiographic quality. This work developed a 2D m1-scout approach in which incremental m1 values were rapidly used to acquire 2D black-blood images and the optimal m1 value can be selected for 3D MRA. Its usefulness is validated on flow phantom and five healthy volunteer legs. This approach may also improve FSD-based vessel wall imaging. 1411. Accelerating Time-Resolved MRA with Multi-Echo Acquisition Hyun Jong Jeong1, Christopher S. Eddleman2, Saurabh Shah3, Nicole Seiberlich4, Mark A. Griswold4, James C. Carr5, Timothy J. Carroll1,5 1Biomedical Engineering, Northwestern University, Chicago, IL, United States; 2Neurosurgery, Northwestern University, Chicago, IL, United States; 3Siemens Medical Solutions, Chicago, IL, United States; 4Radiology, University Hospitals of Cleveland, Cleveland, OH, United States; 5Radiology, Northwestern University, Chicago, IL, United States A new 4D MRA technique called Contrast-enhanced Angiography with Multi-Echo and RAdial k-space (CAMERA) is introduced. With CAMERA, temporal footprint is reduced by a factor of 2 without parallel imaging or undersampling, while increasing SNR. Higher frame rates are achieved by radial sliding window reconstruction. Further acceleration is also possible by incorporating parallel imaging. The technique has been applied to MRA in the intracranial, pulmonary, and renal vessels. Peng Hu1, Michael L. Chuang, Thomas H. Hauser, Kraig V. Kissinger, Beth Goddu, Lois A. Goepfert, Neil M. Rofsky2, Warren J. Manning, Reza Nezafat 1Beth Israel Deaconess Medical Center, Bosto, MA, United States; 2Radiology, Beth Israel Deaconess Medical Center We propose a non-contrast-enhanced free-breathing ECG-gated gradient-echo sequence with a sagittal slab-selective inversion for pulmonary vein (PV) MRA. The inversion pulse was applied to suppress structures adjacent to the left atrium (LA) and PVs, thereby, improving the conspicuity of the PV/LA. The inversion slab thickness and inversion time were optimized on volunteers to be 60mm and 500ms, respectively. The proposed technique significantly increased the CNR between the LA/PV and adjacent structures by 4-20 fold with minimal loss of signal in LA/PV. The PV size measurements of the proposed technique correlated well with clinical contrast-enhanced MRA on 9 atrial fibrillation patients. Erik John Offerman1, Philip Anthony Hodnett, 12, Robert R. Edelman1, Ioannis Koktzoglou1 1Department of Radiology, Northshore University Healthsystem, Evanston, IL, United States; 2Department of Radiology, Northwestern Memorial Hospital, Chicago, IL, United States The link between NSF and Gadolinium has renewed interest in unenhanced MRA techniques that can match the diagnostic potential of contrast-enhanced MRA. Predominant peripheral MRA techniques are evaluated in a 50% stenotic triphasic flow phantom. The techniques are compared by measuring the signal within the stenosis and observing coronal thin MIPs at select flow velocities. The performance of the techniques is dependent on the peak systolic flow velocity of the waveform. Each technique exhibited signal dropout in the area of stenosis at different velocities, and some experienced dropout proximal and distal to the stenosis. Signal vs. flow velocity trend differed between 50% and no stenosis conditions. Anne S. Rasmussen1, Henrik Lauridsen2, Bjarke G. Jensen2, Steen Fjord Pedersen1, Tobias Wang2, Niels Uldbjerg3, Michael Pedersen1 1MR-research Centre Aarhus University Hospital, Aarhus, Denmark; 2Department of Biology, Aarhus University, Aarhus, Denmark; 3Department of Gynaecology and Obstetrics, Aarhus University Hospital, Aarhus, Denmark In vivo angiography is often used in biomedical science. Ex vivo angiography of excised organs or whole body is however rarely used due to the lack of appropriate contrast solutions capable of entering and staying in the vasculature after amputation or death. This study aims to develop contrast solutions and methods for ex vivo MRA and CTA. Two solutions were produced and used for MRA and CTA in four different species. MRA was found to have an advantage to CTA in situations where blood vessels were in close proximity to bones that can interfere with the signal in CTA. 1415. Flow Sensitivity Analysis of Variable Refocusing Angle 3D FSE Wayne R. Dannels1, Xiangxian Shou2, Robert Anderson1, Mitsue Miyazaki3 1Toshiba Medical Research Institute, Mayfield Village, OH, United States; 2Department of Physics, Case Western Reserve University, Cleveland, OH; 3Toshiba Medical Research Institute, Chicago, IL, United States FSE sequences can be adapted either to maintain brightness or to suppress the signal of moving blood. Subtraction methods with FSE can generate angiographic images without injection of contrast agents. 3D FSE variants with variable refocusing angle (VRA) of the echo train are naturally suitable for high scanning efficiency and SAR reduction. Flow sensitivity dependienceis on sequence parameters are analyzed for 3D VRA FSE angiography applications. In vivo testing shows that flow sensitivity can be maintained while SAR is reduced. 1416. Contrast Enhancement for SSFP Angiography with Signal Compensation and Compressed Sensing Tolga Ēukur1, Michael Lustig1, Dwight Nishimura1 1Department of Electrical Engineering, Stanford University, Stanford, CA, United States Magnetization-prepared SSFP angiography can produce vessel images without contrast agents, when coupled with segmented k-space acquisitions. However, the preparation needs to be frequently repeated to effectively capture the transient contrast. Because the vessels have more dominant high-spatial-frequency content compared with the background, compensating for the transient signal decay significantly improves the contrast and resolution, while the resulting noise in sparse angiograms is reduced with compressed sensing. 1417. Breathhold Inhance Inflow IR (BH-IFIR) with a Novel 3D Recessed Fan Beam View Ordering Naoyuki Takei1, Manojkumar Saranathan2, Mitsuharu Miyoshi1, Tetsuji Tsukamoto1 1Applied Science Laboratory, GE Healthcare, Hino, Tokyo, Japan; 2Applied Science Laboratory, GE Healthcare, Rochester, MN, United States Respiratory-gated inflow related non-contrast MR Angiography with selective inversion pulse (inflow IR) has been used clinically in abdomen region. However the use of respiratory gating suffers from motion artifact caused by unstable breathing during scan in a patient. A novel 3D multi-segmented view ordering was proposed to resolve it with breathhold scan. The efficient view ordering allows long data acquisition window while keeping image contrast, resulting in scan time reduction due to decreased number of segments. The our initial study has investigated the possibility of breathhold scan and demonstrated that high contrast between artery and background tissues and uniform blood signal along with reduced scan time were achieved. Lauren Keith1, Steve Kecskemeti1, Yijing Wu1, James Holmes2, Kang Wang1, Reed Busse2, Frank Korosec1,3 1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Applied Science Lab, GE Healthcare, Madison, WI, United States; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States Vastly undersampled Isotropic Projection Reconstruction (VIPR) [1] techniques have been successfully utilized for time-resolved contrast-enhanced MR angiography (CE-MRA) studies. In this work, we explore the benefits of using the VIPR k-space sampling trajectory, in combination with the HYPR LR processing method, for obtaining high spatial and temporal resolution CE-MRA images of the lower extremities. 1419. High Resolution MR Flouroscopy Parmede Vakil1, Hyun J. Jeong, Himanshu Bhat, Christopher Eddleman2, Tiomthy J. Carroll 1Radiology, Northwestern University, Chicago, IL, United States; 2Northwestern Memorial Hospital We present a novel 2D MRI pulse sequence for CE MRA with sliding window reconstruction and complex subtraction. Our pulse sequence produces a time-series of projection images through a thick volume. Time-series images have high spatial resolution (0.57 mm x 0.57 mm) capable of visualizing small arteries, small temporal foot print (~2 seconds/acquisition) and high frame rate (6 fps) making them useful for imaging hemodynamics of intracranial vascular pathologies such as AVMs or aneurysms. We are currently engaged in an ongoing study applying our sequence to AVM patients. Imaging results will be presented. 1420. Rapid Non-Contrast-Enhanced Renal Angiography Using Multiple Inversion Recovery Hattie Zhi Chen Dong1, Pauline W. Worters2, Holden H. Wu1,3, Tolga Ēukur1, Brian Andrew Hargreaves2, Dwight G. Nishimura1, Shreyas S. Vasanawala2 1Electrical Engineering, Stanford University, Stanford, CA, United States; 2Radiology, Stanford University, Stanford, CA, United States; 3Cardiovascular Medicine, Stanford University, Stanford, CA, United States We investigate the use of multiple inversion recovery (MIR) preparation for rapid non-contrast-enhanced renal angiography without image subtraction or breath-holding. MIR preparation consists of selective spatial saturation followed by several nonselective inversions to suppress a range of background T1 species, while maintaining signal from arterial inflow. Two readout approaches were chosen: alternating TR balanced SSFP (ATR-bSSFP) to provide good blood SNR with added fat suppression, and half-Fourier single-shot FSE (SSFSE) to fully capture the MIR contrast preparation. Using the two sequences, projective renal angiograms were produced in 3 and 1 heartbeat(s) respectively. 1421. Non-Enhanced Vs. Contrast-Enhanced MRA at 7Tesla: a Feasibility and Comparison Trial. Lale Umutlu1, Thomas C. Lauenstein1, Oliver Kraff2, Stefan Maderwald2, Stephan Orzada2, Sonja Kinner1, Christina Heilmaier1, Gerald Antoch1, Mark E. Ladd2, Harald H. Quick2,3 1Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany; 2Erwin L.Hahn Institute for Magnetic Resonance Imaging; 3Institute for Medical Physics, Friedrich-Alexander-University Erlangen-Nürnberg Aim of this pilot study of 7T MRA was to investigate the diagnostic capability of non-enhanced 7T MRA and the feasibility of contrast-enhanced ultrahighfield MRA. 8 healthy subjects were examined on a 7T whole-body MR system utilizing a custom-built 8-channel RF transmit/receive body coil. Qualitative and quantitative analysis results demonstrate the diagnostic superiority of TOF-MRA among the non-enhanced sequences as well as its diagnostic capability towards contrast-enhanced MRA. In Conclusion, this first pilot study of dedicated 7TMRA shows the feasibility of contrast-enhanced MRA, as well as the diagnostic ability of TOF MRA e.g. in case of renal insufficiency. Sandra Huff1, Michael Markl1, Ute Ludwig1 1Department of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany To improve the limited coverage of Time-of-Flight (TOF) arteriography, this study addresses the combination of 2D axial TOF and Continuously Moving Table (CMT) acquisitions for imaging the peripheral arteries. Since arterial blood flow is very pulsatile in the periphery, inflow in acquired slices and thus blood signal intensity depends on the time point of acquisition within the cardiac cycle. To compensate for this artefact, a new CMT gradient echo sequence has been designed, that provides several arterial images per slice position respectively per cardiac cycle and is based on a view sharing principle. Background signal was suppressed via image subtraction. Chia-Ming Shih1,2, Ang Yuan3, Chih-Yuan Chen2, Cheng-Hung Chou2, Hao-Wei Cheng3, Pan-Chyr Yang3, Jyh- Horng Chen1, Chen Chang2 1Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; 2Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan; 3National Taiwan University Hospital, Taipei, Taiwan Evaluation of the different effects of VEGF isoforms such as VEGF121, VEGF165 and VEGF189 on tumor feeding vessels and intratumor vessels may offer important new insight into the process of tumor angiogenesis in non-small cell lung cancer. This study was aimed to visualize tumor angiogenesis induced by different VEGF isoform in non-small cell lung cancer in a murine xenograft model by using High Resolution 3Dimentional Contrast Enhanced- Microscopic MR Angiography (HR 3D CE-mMRA). Hao Shen1, Guang Cao2 1Applied Science Laboratory, GE Healthcare, Beijing, China; 2Applied Science Laboratory, GE Healthcare, Hong Kong, China Renal venogram is important in clinical diagnosis but difficult to image with the existing MRI technique. In this study, we developed a non-contrast-enhanced renal venography using a spatial labeling with multiple inversion pulses prepared balanced steady-state free precession sequence. 1425. Fast Vessel Scout Imaging Based on Continuously Moving Table Acquisitions of Projection Data Sandra Huff1, Michael Markl1, Ute Ludwig1 1Department of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany MRA of the peripheral arteries is typically based on a contrast enhanced multistation bolus-chase approach, which requires good synchronization of data acquisition, table motion and arterial passage of the contrast agent bolus. These challenges imply the need for careful planning for the consecutive acquisitions of the several stations and prior knowledge of the vessel geometry would thus be desirable. This study presents the implementation of a fast peripheral vessel scout based on Continuously Moving Table acquisition of projection data with Time-of-Flight (TOF) contrast. The variation of arterial TOF signal during the cardiac cycle was exploited to enhance blood-background contrast. Caroline Denison Jordan1,2, Pauline Wong Worters1, Shreyas S. Vasanawala1, Bruce L. Daniel1, Marc T. Alley1, Moritz F. Kircher1, Robert J. Herfkens1, Brian A. Hargreaves1 1Radiology, Stanford University, Stanford, CA, United States; 2Bioengineering, Stanford University, Stanford, CA, United States Contrast-enhanced MR angiography is a widely accepted technique for imaging the kidneys, but there are many reasons to explore non-contrast-enhanced MRA methods, including contraindication of gadolinium for patients with kidney disease. We evaluated one non-contrast enhanced MRI technique which has shown promising results: respiratory-triggered bSSFP with In Flow Inversion Recovery (IFIR). We optimized the inversion times at 1.5T and 3T, and then quantitatively and qualitatively compared images of renal and mesenteric arteries. We found better relative contrast and better visualization of renal and mesenteric arteries at 3T. An inversion time of 800 ms gave the optimal relative contrast. 1427. Feasibility of Refocused Turbo Spin Echo (RTSE) for Clinical Noncontrast MRA Samuel W. Fielden1, John P. Mugler III1,2, Patrick T. Norton2,3, Klaus D. Hagspiel2,3, Christopher M. Kramer2,3, Craig H. Meyer1,2 1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 2Radiology, University of Virginia, Charlottesville, VA, United States; 3Medicine, University of Virginia, Charlottesville, VA, United States rTSE hybridizes the increased signal provided by the 180° refocusing RF pulses of RARE and the better flow performance of the fully-refocused gradients and phase alternation of balanced SSFP. Here we demonstrate the feasibility of the rTSE sequence in a clinical setting by acquiring angiograms via the rTSE sequence in patients scheduled for peripheral runoff examinations and, in one patient, by comparing the rTSE angiogram to a TOF angiogram. 1428. Whole Body TOF Mouse Magnetic Resonance Angiography William Lefranēois1, Wadie Ben Hassen, Stéphane Sanchez, Jean-Michel Franconi, Eric Thiaudičre, Sylvain Miraux 1Résonance Magnétique des Systčmes Biologiques, UMR 5536 CNRS-Univ. Bordeaux 2, Bordeaux, Gironde, France, Metropolitan Vascular diseases, particularly atherosclerosis, are a major health problem in developed countries. In some cases, stenosis can become critical and cause coronary heart disease necessitating surgical interventions. Therapy planning in patients with multiple stenosis could be facilitated by using whole body angiography. MR angiography (MRA) method currently used on human, is first-pass MRA using a Gadolinium contrast agent. However, this method can not be used on small animal models. This study aimed to develop a fast Time-of-Flight-MRA method able to screen the whole body in reasonable acquisition times and assess the degree and extent of stenosis. John W. Grinstead1, William Rooney2, Gerhard Laub 1Siemens Healthcare, Portland, OR, United States; 2Oregon Health and Science University MPRAGE is a widely used pulse sequence for T1-weighted anatomical imaging. It has been reported that blood appears extremely bright in MPRAGE at 7 Tesla, and provides excellent vascular information. However, the mechanism for this has not been completely explained. The present work explains the primary source of bright blood MPRAGE at 7 Tesla, and based on this understanding proposes a new technique providing simultaneous high-resolution T1 MPRAGE imaging and non-contrast angiography with excellent background suppression. Andreas Greiser1, Mehmet Akif Gulsun2, Arne Littmann1, Jens Guehring2, Edgar Mueller1 1Siemens AG Healthcare Sector, Erlangen, Germany; 2Siemens Corporate Research, Princeton, NJ, United States Vector-encoded MR phase contrast acquisitions covering a bigger volume show larger errors in velocity due to eddy currents and gradient non-linearities. A new scan method is presented that acquires the volumetric dataset in multiple z-isocentered steps. The resulting corrected velocity images and the influence on the flow quantification results of the descending aorta and flow field visualization were analyzed. The multiply isocentered approach results in an overall increase of peak velocity estimates and flow values. The pixelwise standard deviation of the calculated background phase correction matrices across slices for fixed table position was 1.76 cm/sec vs. 0.61 cm/sec for z-isocentered. 1431. The Essence of Half-FOV Shift Ghost Imaging Leping Zha1, Mitsue Miyazaki1 1Toshiba Medical Research Institute USA, Vernon Hills, IL, United States Simulations with synthesized phantom image data and actual comparisons of reconstruction results from acquired imaging data show that, the ½ FOV shift ghost imaging with purposely controlled differences between the even and the odd k-space line sub-sets is essentially an alternative and practical form of complex subtraction of images from the data sub-sets, which often produces superior results compared to that from the common magnitude subtraction imaging, especially for MR angiography. Yoshiyuki Ishimori1, Masahiko Monma1, Izumi Anno1, Tomoko Miyata2 1Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, Ami-machi, Inashiki-gun, Ibaraki, Japan; 2Toshiba Medical Systems Co. Ltd. Time-Spatial Labeling Inversion Pulse (time-SLIP) techniques are utilized as a non-contrast MR angiography using arterial spin labeling (ASL). However, it takes double time for subtraction process between on/off of ASL to visualize cerebral angiograms because of high signal of cerebrospinal fluid (CSF). Single acquisition time-SLIP using dual inversion pulse was investigated in the phantom and volunteer study. As a result, both of CSF and brain parenchyma were suppressed enough with appropriate inversion times. Thus cerebral angiograms could be visualized sufficiently. Accelerated time-SLIP MRA will be useful in terms of imaging time and scan plane flexibility compared to time-of-flight MRA. 1433. Non Contrast MR Angio by Intrinsic Dephasing of True FISP SMS: Ssfp Minus Ssfp Michael Deimling1, Alto Stemmer1 1Siemens Healthcare, Erlangen, Germany We propose an SSFP (Steady State Free Precession) sequence scheme which is based on the intrinsic very high signal sensitivity of flow phase instabilities from TR to TR interval. A straight forward modification of a true FISP sequence makes the signal susceptible to fast flow of the arteries, but leaves the flow of venes untouched; by simply subtraction of both 3D data sets, an artery only image is created. The method does not need any kind of gating or triggering to separate veins from arteries as is needed in non-contrast enhanced MRA methods like Fresh Blood Imaging. David Ratering1, Christof Baltes1, Christine Lohmann2, Christian M. Matter2, Markus Rudin1,3 1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; 2Institute of Physiology, University Zurich and Cardiology University Hospital Zurich, Zurich, Switzerland; 3Institute of Pharmacology & Toxicology, University Zurich, Zurich, Switzerland High-resolution magnetic resonance angiography (MRA) enables detection and monitoring of atherosclerosis in mouse models of human disease. However, high-resolution MRA suffers from long acquisition times putting high demands on the animals physiological stability. Therefore the feasibility of accelerated MRA of murine supra-aortic vasculature using SENSE was investigated with regard to lesion detection and quantitative morphometric analysis. Evaluations revealed that data collection with acceleration factors R ≤ 3.3 had only minor effects on vessel delineation. No significant differences could be found for the morphometric assessment of stenotic lesions and the determination of degree of stenosis when comparing accelerated to fully-sampled data. 1435. Phase-Enhancement Technique for a Hybrid-Of-Opposite-Contrast MR Angiography Tokunori Kimura1, Masato Ikedo2 1MRI Systems Development Department, Toshiba Medical Systems , Otawara, Tochigi, Japan; 2MRI Systems Development Department, Toshiba Medical Systems, Otawara, Tochigi, Japan We have proposed a MRA technique named Hybrid-of-Opposite-Contrast (HOP) MR Angiography combining time-of-flight (TOF) and flow-sensitive black-blood (FSBB) using dual-echo 3D gradient echo sequence, which was magnitude-based technique. For the purpose of further enhancing blood-to-background contrast, we proposed and assessed a new image processing technique employing corresponding phase maps for 1st echo (TOF) and 2nd echo (FSBB) so as to further enhance blood vessels white and black, respectively. Volunteer brain study was performed. Smaller vessels were further delineated by this technique than the standard magnitude-based HOP images. 1436. Changes in MR Signals Associated with Organizing Processes of Venous Thrombi in Rabbits. Yasuyoshi Kuroiwa1,2, Atsushi Yamashita3, Tosiaki Miyati1, Eiji Furukoji4, Misaki Takahashi3, Toshiya Azuma4, Hiroshi Sugimura4, Shozo Tamura4, Keiichi Kawai1,5, Yujiro Asada3 1Division of Health Sciences, Graduate School of Health Science, Kanazawa University,, Kanazawa, Ishikawa, Japan; 2Department of Pathology, , Faculty of Medicine, University of Miyazaki, Miyazaki, Japan; 3Department of Pathology,, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan; 4Department of Radiology,, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan; 5Biomedical Imaging Research Center, University of Fukui To determine the potential of MR to detect venous thrombosis and to define thrombus age, we examined in vivo MR imaging of rabbit jugular vein thrombi 4 hours, 1, 2, 4 weeks after endothelial denudation and vessel ligation, and assessed the association between signal intensities and cellular and matrix contents. We demonstrated that MRI can reliably and noninvasively detect rabbit jugular vein thrombi, and that sequential changes in T2 and T1 weighted signal intensity may reflect organizing process of the venous thrombus. MRI may noninvasively detect venous thrombosis and define thrombus age which is valuable information for thrombolytic therapy. 1437. Realtime Cine MRI in Mice with a Single-Shot EPI Sequence and the KarhunenLoeve Transform Guangping Dai1, Yu Ding2, Shuning Huang1, Orlando P. Simonetti2, David E. Sosnovik3 1Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School; 2Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University; 3Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States Realtime cine MRI of the mouse heart is reported using a single-shot EPI sequence and the KarhunenLoeve transform. The entire mouse heart can be imaged with this technique in less than 5 minutes, using minimal sedation. This report demonstrates the ability of MRI to be used for high-throughput applications, and compete with echocardiography, in the basic science as well as and clinical settings. 1438. Inflow Inversion Recovery MR Angiography of Renal Arteries at 3.0 T: A Feasibility Study Hiromitsu Onishi1, Tonsok Kim1, Masatoshi Hori1, Takahiro Tsuboyama1, Atsushi Nakamoto1, Hiroki Higashihara1, Mitsuaki Tatsumi1, Kaname Tomoda1, Mitsuhiro Uike2, Shoji Nakagami2 1Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; 2MR Sales & Marketing Department, GE Healthcare Japan, Hino, Tokyo, Japan The aim of the present study was to evaluate the feasibility of noncontrast MR angiography of the renal arteries using an Inflow Inversion Recovery (IFIR) sequence in healthy volunteers at 3.0 T. In nine of 10 cases, MR angiography with excellent image quality was obtained and both sides of renal arteries were finely delineated including peripheral branches. In four of 10 cases, two left renal arteries were observed. In addition, in one of four, two right renal arteries were also observed. The renal arteries were finely delineated by means of noncontrast MR angiography using an IFIR sequence at 3.0 T. 1439. 3D Isotropic Non-Contrast Approach for the Assessment of Carotid Arteries Stenosis at 3T Ravi Teja Seethamraju1, Michael Jerosch-Herold2, Yiu-Cho Chung3, Peter Libby4, Marcelo F. Di Carli5, Raymond Y. Kwong6 1MR R and D, Siemens Medical Solutions, USA Inc., Charlestown, MA, United States; 2Radiology, Brigham and Women's Hospital, Boston, MA, United States; 3MR R and D, Siemens Medical Solutions, USA Inc., Columbus, OH, United States; 4Cardiovascular Medicine, Brigham and Woman's Hospital, Boston, MA, United States; 5Nuclear Medicine, Brigham and Women's Hospital, Boston, MA, United States; 6Cardiovascular Imaging, Brigham and Women's Hospital, Boston, MA, United States We present MPRAGE and SPACE as two isotropic 3D non contrast techniques for the measurement of coronary artery stenosis. While both techniques provide precise measurements of the stenosis, they complement each other with respect to characterization of plaque. Tokunori Kimura1, Shinichi Kitane2, Kazuhiro Sueoka3 1MRI Systems Development Department, Toshiba Medical Systems , Otawara, Tochigi, Japan; 2MRI Systems Development Department, Toshiba Medical Enginieering, Otawara, Tochigi, Japan; 3MRI Systems Development Department, Toshiba Medical Enginieering, Otawara, Tochigi, Japan In-flow time-resolved MR angiography technique employing non-subtraction arterial spin labeling with multiple IR (mIR) technique was proposed. It was, however, difficult for mIR to suppress background tissue of wide range of T1 values from fat to CSF. We proposed alternative N-1 subtraction technique further to suppress background tissue signals while minimizing extra acquisition time. Volunteer brain study was performed on 1.5T imager with 2 mIR pulses designed to suppress brain tissues. Resulting background signals of fat and brain parenchyma were well suppressed only by adding extra acquisition time of 16 sec for base image then subtraction. SAR & Safety Hall B Tuesday 13:30-15:30 Matthias Gebhardt1, Dirk Diehl2, Elfar Adalsteinsson3, Lawrence L. Wald4, Gabriele Eichfelder5 1Siemens Healthcare, Erlangen, Germany; 2Siemens Corporate Technology, Erlangen, Germany; 3Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States; 4Martinos Center for Biomedical Imaging, Harvard University, Charlestown, MA, United States; 5Applied Mathematics II, University of Erlangen-Nuremberg, Erlangen, Germany This work addresses the complexity problem inherent in local SAR estimation for parallel transmission (pTx) and shows that a relatively small subset of carefully selected virtual observation points is adequate for prediction and control of maximum local SAR in pTx. We tested the proposed algorithm to detect local SAR maxima by comparison with an exhaustive search over local SAR distribution in numerical simulations of adult male and female subjects for an 8 channel whole body transmit array. The proposed method of model compression for local SAR successfully captured regions of local SAR maxima, but with dramatically reduced computation cost. 1442. Safety of 17O and 23Na MR Imaging of the Human Brain at 9.4 Tesla Ian C. Atkinson1, Rachel Sonstegaard1, Lilian Bityou2, Neil H. Pliskin2, Keith R. Thulborn1 1Center for MR Research, University of Illinois- Chicago, Chicago, IL, United States; 2Psychiatry, University of Illinois- Chicago, Chicago, IL, United States Current FDA guidelines classify MR devices operating at 8 Tesla or lower as insignificant risk. Vital sign and cognitive performance data supporting the safety of performing non-proton MR imaging of the human brain at 9.4 Tesla are presented. These data add to the growing body of results that suggest ultra-high field MR imaging can be safely performed up to 9.4 Tesla. Gerhard Brinker1, Christian Grosse-Siestrup2, Chie Hee Cho2, Katja Reiter2, Katherina Habekost2, Peter Wust2, Razvan Lazar1, Franz Hebrank1, Eckart Stetter1, Jacek Nadobny2 1Siemens Healthcare, Erlangen, Germany; 2Campus Virchow Klinikum, Charité, Berlin, Germany The SAR limits issued by IEC 60601-2-33 are to some extent unbalanced comparing the whole body SAR limit with the local SAR limit. In order to examine thresholds of tissue damage a measurement setup consisting by the Tx path components of a clinical 3T MR scanner is established. Initial results of RF exposure on dead swine (6.5 W/kg, 30 minutes) are presented. Temperature increments are measured at the hot spot locations both invasively in tissue as well as superficially using infrared camera. The experimental results correspond very well with results of simulation using realistic 3D-voxel model of a swine Sukhoon Oh1, Yeun Chul Ryu1, Zhangwei Wang2, Fraser Robb2, Christopher M. Collins1 1PSU College of Medicine, Hershey, PA, United States; 2GE Healthcare, Aurora, OH, United States Influence of a receive array and failure of its detuning circuit on specific absorption rate (SAR) is investigated with simulations and experiments at 3T. A simple array of two copper loops was placed around an agar-gel phantom. A gap in the circuit was placed and removed to simulate perfect and defective detuning conditions, respectively. In simulations, addition of the ”°decoupled”± array resulted in only a 3% higher average SAR than with no array present, whereas with the ”°defective”± circuit, an increase of 41% was observed. Trends in the SAR distributions between the different cases are similar in experiment and calculation. 1445. Effects of Simplifying Rf Coil 3-D EM Simulation Models on Power Balance and SAR Mikhail Kozlov1, Robert Turner 1Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Sachsen, Germany We have investigated the effect on power balance and SAR of simplifying rf coil 3-D EM simulation models, using co-simulation of the RF circuit and 3-D EM fields. We find that sufficiently accurate SAR and power balance estimation cannot be achieved for actual coils using simplified coil models and any renormalization approach. Simulations must converge by mesh refinement not only for B1+ values, but also for radiated and load absorbed powers, and must include simulation of the scanner gradient shield. The effect on SAR of distance to absorbing boundaries and gradient shield depends strongly on RF coil design. Thus coils and their environment need to be specified as accurately as possible, much better than current common practice. If simulation fails to give the correct power balance it is pointless to calculate SAR. In their current implementations, the Ansoft HFSS frequency domain solver provides much more reliable data, and much faster, than the CST time domain solver. Chien-ping Kao1, Zhipeng Cao1, Sukhoon Oh1, Yeun Chul Ryu1, Christopher M. Collins1 1PSU College of Medicine, Hershey, PA, United States Here we compare the homogeneity in whole-brain excitation that can be achieved with two adjustable transmit channels used to drive a patch antenna and to drive a body array with elements combined as to form two orthogonal mode 1 field patterns. Optimal whole-brain homogeneity achievable with B1 shimming and the resulting SAR is examined for the two approaches separately and combined. Combining the patch and the body array results in appreciable better achievable whole-brain homogeneity with significantly lower average and maximum local SAR than possible with either the patch antenna or body coil alone. 1447. Comprehensive Numerical Study of 7T Transmit-Only, Receive-Only Array Coils Mikhail Kozlov1, Robert Turner1 1Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Sachsen, Germany We present a reliable and fast workflow for comprehensive joint numerical study of 7T transmit-only, receive-only RF coils as complete devices. The flexibility of the workflow allows inclusion of almost all the RF and DC components used for tune/de-tune/match/decoupling. The S-parameter data and B1+ and B1- profiles obtained for a family of loop-based 8-channel TX-only, 8-channel RX-only coils allow estimation of the required impedance of de-tuning circuits. 1448. Fast SAR Estimation Via a Hybrid Approach Shumin Wang1, Jeff H. Duyn1 1LFMI/NINDS/NIH, Bethesda, Center Dr. , United States Estimation of local specific absorption rate (SAR) is a major challenge in high-field (>3.0 Tesla) multi-channel transmission systems. Conventional Finite-Difference Time-Domain (FDTD) method is often found inefficient to give subject-specific results. Recent studies sped up the process by applying Amperes law to obtain electrical field distributions via measured transverse B1 fields. The drawback is that only the longitudinal electrical fields can be calculated, which may yield large discrepancy. We present a fast numerical approach by calculating all three components of magnetic field by an integral-equation method and obtain the electric fields by Amperes law subsequently. Combined with fast subject modeling, this method may provide a viable approach for subject-specific SAR estimations. Lohith Kini1, Matthias Gebhardt2, Khaldoun Makhoul3, Lawrence L. Wald3,4, Elfar Adalsteinsson1,4 1EECS, Massachusetts Institute of Technology, Cambridge, MA, United States; 2Siemens Medical Solutions, Erlangen, Germany; 3MGH, Harvard Medical School, A. A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States; 4Harvard-MIT Division of Health Sciences and Technology, MIT, Cambridge, MA, United States Specific Absorption Rate (SAR) is a major concern in parallel transmission. Calculating the average N-gram SAR arising at each spatial location is a computationally intractable problem. We propose and demonstrate improvements to a recent algorithm, the fast region-growth algorithm, and exploit its parallelizable computation structure by implementing it on a commercial graphics card. This algorithm is up to 4-7 times faster in runtime regardless of model resolution and number of RF pulse time samples while maintaining accuracy with the fast region-growth algorithm. 1450. Fast GPU FDTD Calculations: Towards Online SAR and B1+ Assessment and Control Davi Correia1, Astrid van Lier2, Martijn de Greef1, Henny Petra Kok1, Johannes Crezee1, Cornelis Antonius Theodorus van den Berg2 1Academic Medical Center, Amsterdam, Noord Holland, Netherlands; 2University Medical Center, Utrecht, Netherlands We present a novel implementation of the FDTD method on a graphics card and how the possibility of simulating SAR during an MRI procedure. It is now possible to simulate the electromagnetics fields distribution in minutes or even in seconds, depending on the resolution. 1451. Local SAR in High Pass Birdcage and TEM Body Coils for Human Body Models at 3T Desmond Teck Beng Yeo1, Zhangwei Wang2, Wolfgang Loew3, Mika Vogel3, Ileana Hancu1 1GE Global Research, Niskayuna, NY, United States; 2GE Healthcare Coils, Aurora, OH, United States; 3GE Global Research, Munich, Germany The high pass birdcage body coil is commonly used in MRI for homogeneous excitation while the transverse electromagnetic volume coil is increasing used in high-field parallel transmit systems. In this work, the numerically computed normalized local SAR of four human body models, placed at three clinically relevant landmark positions, were compared for a 16-rung high-pass birdcage coil and a TEM body coil at 3T. Results show that while high local SAR may be predicted under certain conditions, any comparative generalizations of local SAR between these coils are untenable unless validated with a diverse set of human models at key landmark positions. Frank Seifert1, Tomasz Dawid Lindel1, Peter Ullmann2 1Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, D-10587 Berlin, Germany; 2Bruker BioSpin MRI GmbH, Ettlingen, Germany Ensuring RF safety is crucial for parallel transmit MRI. During parallel transmission the E-field distributions inside and outside the body exhibit a complex time evolution which cannot be covered by calorimetric SAR measurements. We introduce an optical electric field sensor (OEFS) to map non-stationary E-fields during parallel transmit MRI. We tested a customized OEFS system for certain static phase settings of a 4-channel transmit array. Our measurements confirmed a pathologic single hot-spot SAR-distribution as expected from FDTD simulations. In conclusion, the featured OEFS is an appropriate tool to identify possible safety issues of parallel transmit technologies. Nicolas Boulant1, Martijn Cloos1, Alexis Amadon1, Guillaume Ferrand2, Michel Luong2, Christopher Wiggins1, Denis Le Bihan1, David Ian Hoult3 1NeuroSpin, CEA, Gif sur Yvette, France; 2Irfu, CEA, Gif sur Yvette, France; 3Institute for Biodiagnostics, National Research Council, Winnipeg, MB, Canada Despite the considerable variations one can observe in peak local SAR among all possible driving configurations of a Tx-array, the question of how robust both SAR and flip angle distributions are with respect to small perturbations remains. A head displacement for instance not only changes the solutions of Maxwells equations but also the tuning of the coils. Now Cartesian feedback has been proposed as a solution to the latter problem. We therefore present the results of simulations showing the effects of small rotations of the head upon the flip angle and SAR with and without Cartesian feedback being applied. 1454. Real Time RF Power Prediction of Parallel Transmission RF Pulse Design at 7T Cem Murat Deniz1,2, Leeor Alon1,2, Ryan Brown1, Hans-Peter Fautz3, Daniel K. Sodickson1, Yudong Zhu1 1Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, United States; 2Sackler Institute of Graduate Biomedical Sciences, NYU School of Medicine, New York, NY, United States; 3Siemens Medical Solutions, Erlangen, Germany Prediction of parallel transmission RF pulse power deposition into a patient is one of the principal challenges at ultra-high field magnetic strength. We introduced real time calibration system to predict the net power consequences of the parallel transmission RF pulse design before employing designed RF pulses into scanner. High accuracy was achieved in the power deposition estimation of designed RF pulses with respect to actual net power measurements. Devashish Shrivastava1, J Thomas Vaughan 1CMRR, Radiology, University of Minnesota, Minneapolis, MN, United States An anatomically accurate porcine head model was developed. The model was developed to help validate the temperature predictions of bioheat equations against direct in vivo fluoroptic measurements and predict non-uniform brain RF heating in swine and humans wearing/not-wearing implantable, conductive medical devices for a variety of field strengths, coil configurations, and head loading positions. The head model was developed by obtaining high resolution images of a porcine head using a Siemens 3T Trio (1.02 mm X 1.02 mm X 1.00 mm, Sequence type: T1MPRAGE) and manually segmenting the brain, cerebral spinal fluid, bone, cartilage, muscle, and air-cavity using MIMICS. Zhipeng Cao1, Christopher T. Sica1, Sukhoon Oh1, John McGarrity1, Timothy Horan1, Bu Sik Park1, Christopher M. Collins1 1PSU College of Medicine, Hershey, PA, United States We present a Bloch-based MRI simulator that considers desired sample, field distributions (B0, B1, E1, Gx, Gy, Gz) and pulse sequence for determining effects of field distributions on images (including noise correlation) and SAR. The software is provided with a few basic libraries for simulation of head and body in 8-element transceiver arrays at 3T and 7T and a GUI for designing and executing some simple pulse sequences, but structure of input files is intentionally simple so users can generate their own sample, field distributions, and sequence files. Many fundamental capabilities are demonstrated. 1457. MRI Acoustic Noise Can Harm Research and Companion Animals Amanda M. Lauer1, Abdelmonem M. El-Sharkawy2, Dara L. Kraitchman2, William A. Edelstein2 1Otolaryngology-HNS, Johns Hopkins School of Medicine, Baltimore, MD, United States; 2Radiology/MRI Division, Johns Hopkins School of Medicine, Baltimore, MD, United States Vertebrate animal MRI is an important part of medical research, and veterinary MRI imaging of companion animals is increasing. Human subjects are generally provided with hearing protection against the loud, potentially damaging acoustic noise produced by MRI scanners; this is generally not done for animal MRI subjects. Hearing damage can interfere with research functions for research animals or quality of life for companion animals. We compare typical MRI noise levels to animal hearing thresholds and conclude that MRI exposes many animals to levels of noise and duration that would exceed NIOSH limits for human exposure. 1458. Subjective Acceptance of Ultra-High-Field MR Imaging at 7T in 573 Volunteers Christina Heilmaier1,2, Jens M. Theysohn1,2, Stefan Maderwald1,2, Oliver Kraff1,2, Lale Umutlu1,2, Mark E. Ladd1,2, Susanne C. Ladd1,2 1Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, NRW, Germany; 2Erwin L. Hahn-Institute for Magnetic Resonance Imaging, Essen, NRW, Germany Subjective acceptance of ultra-high-field MRI has not been evaluated in larger study groups yet. For this purpose, 573 volunteers underwent a 7T examination and were afterwards asked about sensations and side effects. Analysis revealed an overall high subjective acceptance of 7T examinations with mainly non-specific factors such as unpleasant room temperature, little contact to the staff or noise being criticized. Compared to 1.5T volunteers described considerably more often nausea or a metallic taste on 7T; however, the average degree of these effects was very low. Volunteers lying head first expressed more complaints than those lying feet first. 1459. Dynamic Slew Rate Pulse (DSRP) for PNS Alleviation Yongchuan Lai1 1GE healthcare, Beijing, China In this study, a new gradient pulse, Dynamic Slew Rate Pulse (DSRP), is designed to reduce peripheral nerve stimulation (PNS). Compared with traditional trapezoid pulse, DSRP”Æs pulse width is much smaller when dB/dt limitation is dominant. 1460. Exposure Measurements on MR-Workers at the Stray Field of 1.5T, 3T, and 7T MR Systems Jens Groebner1, Reiner Umathum2, Michael Bock2, Wolfhard Semmler2, Jaane Rauschenberg2 1Medical Physics in Radiology , German Cancer Research Center, Heidelberg, Germany; 2Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany Due to the insufficient experimental data on static magnetic field exposure and new ICNIRP limitations an exposure measurement instrument was developed. With the new probe actual B0 and time varying magnetic fields due to movement in the stray field can be detected simultaneously. Therefore, personal exposure of 10 healthcare workers and MR physicists during normal operating procedures could be determined. Peak exposure limits are exceeded during all procedures. 1461. Physical Simulation Study of Active Noise Control Up to 5 KHz Rudd W. Bernie1, Li Mingfeng1, Teik C. Lim1, Jing-Huei Lee2 1Mechanical Engineering, University of Cincinnati; 2Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States We demonstrate that active noise control (ANC) is feasible to treat MRI noises at frequencies greater than 2 KHz. Several MRI scan noise and gradient signals were recorded and replayed in a sound quality chamber to simulate the MRI environment. A dummy wore headphones containing piezoceramic speakers with condenser microphones installed inside and outside the earpiece to measure the environmental sound in the immediate patient vicinity. During the simulation study, the sound pressure level (SPL) was measured, both with and without the ANC. Results presented show the ANC system attained significant SPL reduction at all frequencies up to 5 kHz. 1462. Dental MRI: Compatibility of Dental Materials Olga Tymofiyeva1, Sven Vaegler1, Kurt Rottner2, Julian Boldt2, Peter Christian Proff3, Ernst-Juergen Richter2, Peter Michael Jakob1 1Dept. of Experimental Physics 5, University of Wuerzburg, Wuerzburg, Bavaria, Germany; 2Dept. of Prosthodontics, Dental School, University of Wuerzburg, Wuerzburg, Germany; 3Dept. of Orthodontics, Dental School, University of Regensburg, Regensburg, Germany Recently, new approaches for application of MRI in various branches of dentistry have been proposed. Dental materials present in the subjects mouth pose a major concern for dental applications of MRI. Partly contradictory results have been reported regarding the severity of image artifacts caused by different dental materials, usually without consideration of dental applications of MRI. This paper provides classification of standard dental materials from the standpoint of dental MRI, and can serve as a guideline in future dental MRI research. 1463. De-Fibrillation in an MRI Environment Gene Payne1,2, Sathya Vijayakumar1,2, Eugene Kholmovski1,2, Jayne Davis3, Josh Blauer, 2,4, Chris Gloschat, 2,4, Kimberly Lilbok5, Rob MacLeod, 3,4, Dennis Parker1,2, Nassir F. Marrouche5 1UCAIR, Department of Radiology, University of Utah, Salt Lake City, UT, United States; 2CARMA Center, University of Utah, Salt Lake City, UT, United States; 3CVRTI, University of Utah, Salt Lake City, UT, United States; 4Dept. of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States; 5Dept. of Cardiology, University of Utah, Salt Lake City, UT, United States While imaging subjects in an MRI scanner, it may sometimes be necessary to de-fibrillate in order to restore sinus rhythm or resuscitate. Normal de-fibrillator equipment is incompatible with the scanner's magnetic field. Presented is a procedure for de-fibrillating inside the MRI environment. With this procedure, the defibrillator unit was located outside the MRI environment, with select non-ferrous equipment inside and on the subject. This procedure was employed on four separate occasions with an animal subject on the scanner table, and was found to be successful. No problems or safety concerns were observed. 1464. A Simple Cost-Efficient Magneto Alert Sensor (MALSE) Against Static Magnetic Fields Tobias Frauenrath1, Wolfgang Renz2, Thoralf Niendorf1,3 1Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany; 2Siemens Medical Solutions, Erlangen, Germany; 3Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany While MR is a diagnostic imaging tool which saves lives, magnetic forces of fringe magnetic field components of MR systems on ferromagnetic components can impose a severe occupational health and safety hazard. With the advent of ultrahigh field MR Systems including passively shielded magnet versions this risk - commonly known as missile effect /1/ - is pronounced. Numerous accidents have been reported ranging from mechanical damage to patient death. These casualties are probably most widely known through television documentaries and printed media but still present the tip of the iceberg of safety violations (/2/ /3/ /4/). Various policies have been implemented around the world to safeguard healthcare workers, volunteers and patients with the ultimate goal of avoiding unforeseen disasters and injuries. Transmit Array Control Hall B Wednesday 13:30-15:30 1465. Tuning the Output Impedance of RF Power Amplifiers with Frequency-Offset Cartesian Feedback Marta Gaia Zanchi1, Pascal Stang1, John Mark Pauly1, Greig Cameron Scott1 1Electrical Engineering, Stanford University, Stanford, CA, United States We present a method and system based on Frequency Offset Cartesian feedback (FOCF) to electronically manipulate the output impedance of the RF power amplifiers for MRI transmitter arrays. In comparison to other methods, the output impedance synthesized by FOCF can have any value within a large area of the Smith chart, is stable over the power range, and does not hamper the amplifier efficiency. Through simulations and measurements, we demonstrate the ability to predictably manipulate the output impedance of a power amplifier near 64 MHz from very low to very high values. Marta Gaia Zanchi1, Pascal Stang1, John Mark Pauly1, Greig Cameron Scott1 1Electrical Engineering, Stanford University, Stanford, CA, United States Frequency Offset Cartesian feedback (FOCF) has been proposed to deal with the challenges associated with control of the RF transmission fields in arrays of coils. Critical milestones in the development of a FOCF system are to guarantee that stability existand can be found automaticallyup to the full rated power of the RF amplifier, and to measure the increased performance of the amplifier for several control variables. In this work, we present the hardware and simulation methods developed to characterize and study stability and performance of our system, as well as the results of these milestone tests. 1467. Investigation Non-Magnetic Amplifiers Applied in an MRI System Xing Yang1, Xu Chu2, Tingting Song2, Thomas K Foo3, Desmond Teck Beng Yeo3 1GE Global Research Center , Shanghai, China; 2GE Global Research Center, Shanghai, China; 3GE Global Research Center, Niskayuna, NY, United States Power loss saving and cost reduction can be achieved by placing the RF amplifiers near the magnet directly. This will requires that the amplifiers are compatible within a high magnetic field environment. In this study, a 1 kW (peak power) non-magnetic amplifier module was designed and constructed. The impact of the B0 field on the non-magnetic amplifier and the effect of non-magnetic amplifier on the performance of the system were investigated. The experimental results indicated that, at 3T, the magnetic field had no notable impact on the MOSFET behavior. Similarly, the non-magnetic amplifier had no appreciable impact on image quality. 1468. An Automated Cartesian Feedback Transceiver for Use in High Magnetic Fields David Ian Hoult1, Glen Kolansky1, Derek Foreman1, John Rendell1, Mikhail Barklon1, Karl Edler1, Lawrence Ryner1, Denis Le Bihan2 1Institute for Biodiagnostics, National Research Council Canada, Winnipeg, Manitoba, Canada; 2Commissariat ą l'énergie atomique, NeuroSpin, Gif-sur-Yvette, France Magnetic resonance has been performed at 123.2 MHz with an automated Cartesian feedback instrument immersed in ~ 2 T field. No change of electronic characteristics was observed upon field immersion. With a probe having a loaded Q-factor of 20, 40 dB current blocking with a 500 W RF power amplifier was obtained over a bandwidth of 20 kHz. A rectangular high power RF pulse exhibited no visible droop or phase change, while a ramp pulse exhibited no visible non-linearity or phase change. In signal reception over 160 kHz, current blocking of 40 dB was observed, a performance previously unattainable. B1 Mitigation Methods Hall B Thursday 13:30-15:30 Jonathan C. Sharp1, Donghui Yin2, Boguslaw Tomanek1, Scott B. King2 1Institute for Biodiagnostics (West), National Research Council of Canada, Calgary, AB, Canada; 2Institute for Biodiagnostics, National Research Council of Canada, Winnipeg, MB, Canada Imaging without B0-gradients by the TRASE method is based on echo trains with refocusing pulses produced by RF phase gradient fields. K-space evolution occurs between successive echoes. The use of phase gradients means that pulse phases vary spatially. Also |B1| inhomogeneity, causing flip-angle errors, is always present. Both effects combine to result in each location in the sample experiencing a different pulse sequence, which results in a position-dependent point-spread-function (PSF). We examine how the relationships between sequence design, coil design and flip angle calibration can be used to maximize the sample volume offering a good PSF. 1470. Slice-Selective B1 Phase Shimming at 9.4 Tesla Jens Hoffmann1, Juliane Budde1, Gunamony Shajan1, Rolf Pohmann1 1High Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tuebingen, Baden-Wuerttemberg, Germany In this work, we demonstrate B1 phase shimming in situ at 9.4 Tesla: A rapid calibration pre-scan provides B1+ magnitude and phase maps that are used to predict the total field across the subject dependent on a phase configuration of choice. In addition, a GUI provides the option to select a region within a slice where the field is quickly and reliably optimized by a simulated annealing algorithm based on a suitable optimization criterion. The accuracy of this method is demonstrated in a saline phantom and used for B1 shimming in the human brain. 1471. A Geostatistical Approach to Denoise and Interpolate Experimental Complex-Valued B1 Maps Guillaume Ferrand1, Michel Luong1, Pierre Chauvet2, Martijn Anton Cloos3, Alexis Amadon3 1IRFU/SACM, CEA Centre de Saclay, Gif sur Yvette, France; 2Centre de Géosciences, Mines ParisTech, Fontainebleau, France; 3DSV/I2BM/NeuroSpin/LMRN, CEA Centre de Saclay, Gif sur Yvette, France The knowledge of the complex-valued B1 map generated by each channel of a phased-array RF coil has become essential for high field MRI systems operating above 7 T, a cornerstone for static or dynamic shimming techniques, whose aim is to provide a uniform excitation over any ROI. The maps must be measured experimentally for each RF coil and each subject under examination using an MRI sequence; the more accurate and space resolved the maps, the higher the shimming quality. Unfortunately, high quality maps are time consuming and usually lead to a stronger SAR exposure for the subject. We propose in this abstract a new method based on geostatistical considerations to post-process noisy and poor space resolved B1 maps. 1472. Investigation of Slice Excitation Using Transmit Arrays and Non-Selective RF Pulses Mary Preston McDougall1,2, Steven M. Wright, 12, Ke Feng2, Edwin Eigenbrodt2, Chieh Wei Chang1, Neal Hollingsworth2, John Bosshard2 1Biomedical Engineering, Texas A&M University, College Station, TX, United States; 2Electrical and Computer Engineering, Texas A&M University, College Station, TX, United States Curved slice excitation has been used for imaging the spine and neck, cortical surface of the brain, and other applications. RF pulses for generating curved slices are typically 2D or 3D pulses, and can be very time consuming. This paper presents an approach which may be useful in certain applications, in which an array coil, conformed to the surface of interest, generates the slices using simple non-selective pulses. Slice depth is controlled by pulse duration or power. Examples are shown using a straightforward forced current approach using a single transmitter and a more general approach using a 64 channel transmitter. 1473. Statistical Analysis of in Vivo B1 Maps at 7T Douglas Kelley1,2 1Applied Science Laboratory, GE Healthcare, San Francisco, CA, United States; 2Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States The design of practical B1 compensation schemes requires knowledge of the statistical properties of the B1 distribution found in vivo. An analysis of B1 maps in the brain of 10 human subjects is presented, identifying several common features and highlighting the non-Gaussian nature of the distribution. 1474. A Complementary Images Shimming Method to Mitigate B1 Inhomogeneity for High Field MRI Guillaume Ferrand1, Michel Luong1, Martijn Anton Cloos2, Alexis Amadon2 1IRFU/SACM, CEA Centre de Saclay, Gif sur Yvette, France; 2DSV/I2BM/NeuroSpin/LMRN, CEA Centre de Saclay, Gif sur Yvette, France The B1 inhomogeneity is well known to be a source of artifact in high field MRI, and requires the use of multiple-channel parallel transmit coil to reduce the artifact by making either the B1 distribution (static shimming) or the flip angle distribution (dynamic shimming) as uniform as possible. We present here an intermediate and versatile approach to mitigate B1 inhomogeneity based on the principle of complementary images averaging (CIA) while maximizing the signal to noise ratio (S/N). Gwenael Henri Herigault1, Gert H. van Yperen1 1BU-MRI, Philips Healthcare, Best, Netherlands 3D turbo spin echo (TSE) sequences with variable flip angles (VFA) have shown their potential for 3T body imaging. However, they come with an increased sensitivity to B1 inhomogeneity. Multi-channel parallel RF Transmission (MTX) has demonstrated that it is possible to improve B1 homogeneity and flip angle accuracy inside the body at high field. This paper reports our initial experience using a 3D TSE-VFA sequence in combination with a MTX technology for abdomen and male pelvis 3T imaging. Significant signal and contrast uniformity improvements are reported using MTX as compared to the conventional 3T single RF channel technology. Simulations: B1 Uniformity Hall B Monday 14:00-16:00 1476. Rapid B1 Field Calculation Using Integral Equations for RF Shimming Hyoungsuk Yoo1,2, Anand Gopinath1, Thomas Vaughan1,2 1Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States; 2Department of Radiology, Center for Magnetic Resonance Research, Minneapolis, MN, United States In the method of moments, triangular patches and the Rao-Wilton-Glisson (RWG) basis functions to arbitrary shaped homogeneous lossy dielectric objects are used. The single TEM coil is modeled for 9.4T (400MHz) system, then electromagnetic scattering problem by human phantom model is solved based on the method of moments technique solution of the combined field integral equations. 1477. GPU Accelerated FDTD Solver and Its Application in B1-Shimming Jieru Chi1, Feng Liu2, Ewald Weber2, Yu Li2, Riyu Wei2, Wenlong Xu3, Adnan Trakic2, Hua Wang2, Stuart Crozier2 1Qingdao University, Qingdao, China; 2The School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, St.Lucia, Queensland, Australia; 3Dept. of Biomedical Engineering, China Jiliang university, Hangzhou, China This study extends our recent works on CPU-base FDTD simulations into a Graphics Processing Unit (GPU)-based parallel-computing framework, producing substantially boosted computing efficiency at only PC-level cost. The new computational strategy enables intensive computing feasible for solving forward-inverse EM problems in modern MRI, as illustrated in the high-field B1-shimming investigation presented herein. Moreover, the new rotating RF excitation technique proposed here can compensate for B1 inhomogeneities while simultaneously controlling SAR and as such may have a number of applications in high-field MRI. 1478. Optimum Coupling of Travelling Waves in a 9.4T Whole-Body Scanner Frank Geschewski1, Jörg Felder1, N. Jon Shah1,2 1Institute of Neuroscience and Medicine 4, Forschungszentrum Jülich GmbH, Juelich, NRW, Germany; 2Faculty of Medicine, Department of Neurology, RWTH Aachen University, Aachen, Germany We investigated optimum coupling of a newly designed patch antenna into the RF screen of a 9.4T whole body MR system. 1479. RF Wave and Energy Propagation in High Field MRI Christopher M. Collins1, Chienping Kao1, Andrew G. Webb2 1PSU College of Medicine, Hershey, PA, United States; 2Leiden University Medical Center, Leiden, Netherlands As shown in both animations of B1 field magnitude through time and Poynting vector analysis, travelling waves have significantly shorter length and slower speed in human tissues than in the surrounding air, and thus experience significant refraction at the surface of the body, resulting in a direction of travel within the body that is fairly independent of the original source. Nevertheless, how these waves interfere within the body to create B1 and E1 field patterns relevant to MRI depends very much on the position, geometry, and orientation of the source(s). 1480. Contribution of the Inherent Traveling Wave in 7T to Large FOV Imaging Bei Zhang1, Daniel K. Sodickson1, Qi Duan1, Graham Wiggins1 1CBI, Department of Radiology, New York University, NEW YORK, NY, United States As the traveling wave has become a hot topic in high field MR as a promising method for large FOV imaging since ISMRM 2008, a lot of applications of traveling wave in imaging have been discussed. Since the conductive interface in 7T allows the propagation of TE11 mode, all excitations can create a TE11 mode in the interface. Therefore, it needs to understand the traveling wave contribution even in the conventional transmission and reception methods. In this work, we do full-wave electrodynamic simulations with a body model to explore the contribution of the conductive surface to the large FOV imaging with a conventional excitation method. From the simulation results, it can be seen that the traveling wave created in the conductive interface extends the FOV and boosts the SNR. It is also found that: in order to effectively excite the working mode, the position of the excitation should be that the current distribution in the excitation and the H field pattern comply with the right-hand law. Bobo Hu1, Sedig Farhat2, Paul Glover2 1Sir Peter Mansfield Magnetic Resonance Centre , University of Nottingham, Nottingham, United Kingdom; 2Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, United Kingdom The RF field inhomogeneity in the human brain imaging utilizing the travelling wave technique is a fundamental obstacle of its clinical implementation. This work proposes a horn antenna type of structure to improve the coupling of the travelling wave to the head and also enhance the field homogeneity, especially at the upper cerebrum area. Both the simulated B1 field map and Poynting vector plot shows the field homogeneity has been improved and more power flows into the head. The hot-spots at top of the cerebrum and forehead area are greatly reduced. A comparison of its performances against patch antenna and patch antenna with a match load were studied by using the numerical simulation (xFDTD, Remcom. Inc, PA). 1482. Using Dielectrics and RF Shielding to Increase B1+ Efficiency and Homogeneity Jinfeng Tian1, Carl J. Snyder1, J. Thomas Vaughan1 1University of Minnesota, Minneapolis, MN, United States Using finite difference time domain simulations, the effect of different relative permittivity of the dielectric located between the body and volume array at 7T is examined. Additionally, RF shielding within the volume array is studied to predict B1 transmit patterns in the body. These are combined to improve B1 efficiency and homogeneity at 7T. 1483. Comparison on the Traveling Wave Excitation and the Conventional Excitation Bei Zhang1, Daniel K. Sodickson1, Riccardo Lattanzi1, Qi Duan1, Ryan Brown1, Bernd Stoeckel2, Graham Wiggins1 1CBI, Department of Radiology, New York University, NEW YORK, NY, United States; 2Siemens Healthcare This abstract uses the finite difference time domain (FDTD) method to simulate a stepped-diameter traveling wave system and TEM resonator system loaded with the same body model, and compare the simulation results of these two systems in terms of B1 mapping, SAR distribution and system efficiency. The result shows that the traveling wave system and conventional TEM body coil in 7T are simulated to compare in terms of B1 mapping, SAR distribution and system efficiency. Both systems show strong B1+ inhomogeneities in the torso, though these could in principle be mitigated with a parallel multi-port TEM excitation. The combination of strong attenuation of the traveling wave and high SAR in tissues near the patch antenna make the TWS less suitable for whole body imaging than a local standing wave transmitter such as the TEM. 1484. B1+ Uniformity in Birdcage Body Coils Versus the Alignment and Shape of the RF Shield Arslan Amjad1, Eddy B. Boskamp1 1GE Healthcare, Waukesha, WI, United States In order to make an image without shading, it is critical for the body coil to produce homogeneous B1+ field inside the imaging volume. Any variation in the shape or the alignment of either the body coil or the RF shield can deteriorate B1+ homogeneity and hence image quality. In this work the impact on B1+ field homogeneity using numerical simulations is studied under various non-ideal conditions. 1485. A Simulational Study on the Homogeneity of Dual-Tuned Birdcage Coils William M. Potter1,2, Luning Wang1,2, Kevin McCully3, Qun Zhao1,2 1Physics and Astronomy, University of Georgia, Athens, GA, United States; 2Bioimaging Research Center, University of Georgia, Athens, GA, United States; 3Kinesiology, University of Georgia, Athens, GA, United States 31P magnetic resonance spectroscopy signal sensitivity is low due concentrations of the nucleus and magnetic field inhomogeneity from currently available commercial surface coils. Dual-tuned (1H/31P) birdcage coils are advantageous in that they create a very homogeneous B1 field inside the coil. The practicality of building a dual-tuned coil, however, can be troublesome due to many factors such as coil structure (e.g., # of legs/rings, dimensions) and biological objects to be imaged. In this abstract, the homogeneity comparisons for the 8-leg, 16-leg, and the 24-leg, 4-ring low-pass birdcage coils are presented with the presence of simulated human head and thigh modules. 1486. B1 Shimming Performance Versus Channel/Mode Count Paul R. Harvey1, Cecilia Possanzini1, Jan Simons1 1Philips Healthcare, Best, Netherlands This study reports on simulations of abdominal B1 shimming performance, using a multi-element volume body coil, as a function of transmit channel/mode count and available RF power. Results indicate that increasing channel/mode count provides limited improvement in uniformity at the cost of higher power. Receive Arrays & Coils Hall B Tuesday 13:30-15:30 1487. Selection and Verification of a Throughput-Optimized Receive Array for Multiple-Mouse DCE-MRI Marc Stephen Ramirez1, James Andrew Bankson1 1Department of Imaging Physics, The University of Texas M. D. Anderson Cancer Center, Houston, TX, United States A variety of receive array coil configurations were simulated to determine acceptable parallel imaging reduction factors for use in accelerated multiple-mouse MRI. Based on these results, timing of accelerated multi-mouse DCE-MRI protocols were predicted and compared with timing of a single-mouse, single-coil DCE-MRI protocol to estimate improvements in throughput. The coil configuration that yielded the highest multi-mouse throughput improvement was determined. A phased-array coil based on the optimal configuration was designed, fabricated, and used for phantom imaging to verify that the predicted reduction factor per animal maintained image quality suitable for routine small-animal imaging studies. Akira Nabetani1, Masayuki Yamaguchi2, Akira Hirayama1,2, Minoru Mitsuda2,3, Ryutaro Nakagami2,3, Atsushi Nozaki1, Mamoru Niitsu3, Hirofumi Fujii2,4 1GE Healthcare Japan, Ltd., Hino, Tokyo, Japan; 2Functional Imaging Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan; 3Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, Japan; 4Institute for Bioinformatics Research and Development Japan Science and Technology Agency, Chiyoda, Tokyo, Japan We constructed and tested a new multiple-animal magnetic resonance imaging (MRI) device that uses a 3-Tesla (3-T) whole-body scanner. An array coil comprising 16 small circular coils was connected to 16 preamplifiers and receivers of the scanner. This device can be used to perform simultaneous whole-body scanning of 4 rats or 16 mice. This approach facilitates progress in preclinical MRI and may be helpful in pharmaceutical drug-development studies in which various doses of multiple compounds are assessed in a large number of animals. 1489. An 8-Channel Coil Array for Small Animal 13C MR Imaging Jian-Xiong WANG1, Nan Tian2, Fraser J. Robb3, Albert P. Chen4, Lanette Friesen-Waldner5, Brian K. Rutt6, Charles A. McKenzie5 1Applied Science Laboratory, GE HEALTHCARE, London, ON, Canada; 2Department of Radiology, University of California at San Fransisco, San Fransisco, CA, United States; 3GE HEALTHCARE, Aurora, OH, United States; 4GE HEALTHCARE, Toronto, ON, Canada; 5The Department of Medical Biophysics, The University of Western Ontario, London, ON, Canada; 6Department of Radiology, Stanford University, Stanford, CA, United States Synopsis: This work presented an 8-channel 13C receive coil array/preamp system with associated detunable transmit coil system for a clinic MRI scanner without additional hardware or modification to the scanner. Both MRI and CSI were obtained with this coil system. This offers parallel imaging possibility for metabolic imaging utilizing short lifetime hyperpolarized [1-13C]-pyruvate of the hyperpolarized 13C spins in solution. 1490. A 21 Channel Transceiver Array for Non-Human Primate Applications at 7 Tesla. Gregor Adriany1, Noam Harel1, Essa Yacoub1, Steen Moeller1, Geoff Ghose1, Kamil Ugurbil1 1Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, MN, United States A combination of a 16 channel transceiver stripline array with a close fitting 5 channel receive loop array for non human primates applications is presented. The coils are arranged to allow simultaneous reception with all 21 elements and combine the benefits of close fitting receive only arrays with multi-channel transmit arrays. For a reduction factor of 3 the average g-factor for the combination of 16+5 receiver channels improved to 1.62 compared to 2.66 for the 5 channel coil. 1491. A 32 Channel Receive-Only 3T Array Optimized for Brain and Cervical Spine Imaging Azma Mareyam1, Julien Cohen-Adad1, James N. Blau1, Jonathan R. Polimeni1, Boris Keil1, Lawrence L. Wald1,2 1A. A. Martinos Center for Biomedical Imaging, Dept. of Radiology, Masschussetts General Hospital, Charlestown, MA, United States; 2Division of Health Sciences and Technology, Harvard-MIT, Cambridge, MA, United States Imaging of the cervical spinal cord along with the brain is crucial for the study of such pathologies as multiple sclerosis. Progress, however, is impeded by distortion and susceptibility artifacts, due to the cord's small size and to adjacent B0 inhomogeneities. We designed and built a new, highly-parallel 32 channel coil array to provide sufficient resolution, SNR and acceleration for imaging the brain, brainstem, and cervical vertebrae. Characterization of the coil showed SNR and acceleration improvement over existing Siemens head, neck and spine coils in this region. 1492. Modular Coil Array for Highly Accelerated 2D Parallel Acquisition Clifton R. Haider1, Thomas C. Hulshizer1, Casey P. Johnson1, Petrice M. Mostardi1, Phillip J. Rossman1, Stephen J. Riederer1 1Radiology, Mayo Clinic, Rochester, MN, United States The purpose of this work is to demonstrate the design and use of modular coil arrays that allow highly accelerated (R=8) 2D SENSE to be exploited in providing high diagnostic image quality for 3D contrast-enhanced MR angiograms in multiple vascular territories across a broad range of patient sizes. Volunteer and patient studies were conducted in the calves, feet, hands, brain, thighs, and abdomen. Results demonstrate high diagnostic image quality. 1493. Design Optimization of a 32-Channel Head Coil at 7T Boris Keil1, Christina Triantafyllou1,2, Michael Hamm3, Lawrence L. Wald1,4 1A.A. Martinos Center for Biomedical Imaging, Department of Radiology, MGH, Harvard Medical School, Charlestown, MA, United States; 2A.A. Martinos Imaging Center, Mc Govern Institute for Brain Research, MIT, Cambridge, MA, United States; 3Siemens Healthcare, Charlestown, MA, United States; 4Harvard-MIT Division of Health Sciences and Technology, MIT, Cambridge, MA, United States The development of high-field coils with an increasing number of elements places increasingly constraints on the arrangement of the components, including preamplifier, cables and cable traps. For maximum spatial efficiency and reduced losses, most of the components needed to be placed adjacent to the corresponding coil loop. Reduced interaction with the transmit coil requires a sparse configuration of conductors, well isolated through cable traps. In this study a new generation of a 32-channel coil at 7T was constructed, tested, and compared to a previous 32-channel design. Substantial changes have been implemented to achieve better SNR, increased stability, lower transmit power. 1494. Feasibility of Constructing Receive-Only Arrays for Human Imaging at 11.7T and 14T Azma Mareyam1, Jonathan R. Polimeni1, James N. Blau1, Lawrence L. Wald1,2 1A. A. Martinos Center for Biomedical Imaging, Dept. of Radiology, Masschussetts General Hospital, Charlestown, MA, United States; 2Division of Health Sciences and Technology, Harvard-MIT, Cambridge, MA, United States Arrays of surface coils employing lumped capacitance are in widespread use at 7T, but become problematic at extremely high fields as stray capacitances and losses from discrete components increase. We constructed coils for 11.7T and 14.1T (500 and 600 MHz) using a double-sided microwave circuit board material milled into overlapping sections. Arrays of these distributed-capacitance coils were characterized, outperforming equivalent lumped-capacitance arrays at loaded to unloaded Q ratios. 1495. A Numerically Optimised Receive-Only Coil Array at 3 T Andreas Peter1, Stefan Schonhardt1, Jan G. Korvink1,2 1University of Freiburg - IMTEK, Freiburg, Germany; 2Freiburg Institute of Advanced Studies (FRIAS), Freiburg, Germany In this contribution, we present the optimisation of a 2D coil array in order to decouple all adjacent and next neighbouring coils simultaneously. We have extended the geometric overlapping approach to non-adjacent elements by shape-optimisation of the coil elements. A combination of Matlab and FastHenry was used to optimise an array of seven elements at 3 T. From the optimised design, we produced a set of PCBs of the single hexagonal elements on a flexible polyimide substrate. All adjacent elements showed an isolation of > 25 dB, the next neighbouring elements even > 30 dB.
1496. A User-Configurable 96 Channel Head Array for Use in a 32 Channel 3T System Thimo Grotz1, Boris Keil2, Azma Mareyam2, Simon Sigalovsky2, Benjamin Zahneisen1, Maxim Zaitsev1, Jürgen Hennig1, Lawrence L. Wald2 1Dept. of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany; 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States Surface coils with a high numbers of receive elements are an important tool for many applications. Commercial scanners usually dont support such high numbers of receive elements and non-standard hardware upgrades are needed to use such arrays. We present a 3T scanner compatible 96 channel head array coil which allows the selection of an arbitrary subset of 32 receiver channels from the 96 channels available, which makes it possible to benefit from the use of small receive elements on a standard MRI system. Jörn Ewald1, Florian M. Meise1, Stefan Fischer2, Torsten Hertz1, Torsten Lönneker-Lammers3, Laura Maria Schreiber2 1LMT Medical Systems GmbH, Luebeck, Germany; 2Section of Medical Physics, Department of Diagnostical and Interventional Radiology, Mainz University Medical School, Mainz, Germany; 3LMT Lammers Medical Technology GmbH, Luebeck, Germany For a detailed understanding of diseases and developmental processes during the first year of live without harming the patient by using ionizing radiation, MRI of the neonatal brain is mandatory. So far this could be achieved by using an MR-safe. Because reduction of scan time (minimizing movement artifacts and specific absorption rate) is needed, phased array coils to apply parallel imaging techniques have to be developed. Since comparable field strength studies, for analyzing influences of image contrasts, may be performed, an 8-channel phased array head coil implemented in an MR-safe incubator was designed for 1.5T and 3T in this study. Florian M. Meise1, Jörn Ewald1, Stefan Fischer2, Torsten Hertz1, Torsten Lönneker-Lammers3, Laura Maria Schreiber2 1LMT Medical Systems GmbH, Luebeck, Germany; 2Section of Medical Physics, Department of Diagnostical and Interventional Radiology, Mainz University Medical School, Mainz, Germany; 3LMT Lammers Medical Technology GmbH, Luebeck, Germany MRI of newborns got growing attention over the past few years as it provides precise diagnostics without the use of ionizing radiation. Premature infants and newborns need optimum environmental conditions during the measurement procedure, (temperature and humidity). Since there is an MR-safe incubator available, imaging of the brain and thorax under optimum conditions is possible. Especially at high fields, SAR limits and movement artifacts from the patient can be challenging. Both issues can be dealt with by applying parallel imaging techniques. To Also to improve SNR with multi-element arrays, an 8+4-channel phased array implemented in an MR-safe incubator was designed. Stephen Dodd1, Herman Douglas Morris2, Joseph Murphy-Boesch1, Hellmut Merkle1, Alan Koretsky1 1Laboratory of Functional and Molecular Imaging, NINDS, National Institutes of Health, Bethesda, MD, United States; 2Mouse Imaging Facility, National Institutes of Health, Bethesda, MD, United States In order to take advantage of the sensitivity that high fields offer we have developed and describe here a 4-element receive-only array design for parallel imaging of the mouse brain at 14 T. To achieve the necessary decoupling between array elements we designed and built small, low noise and low input impedance preamplifiers which can fit in the limited diameter of the vertical bore magnet. Double Tuned RF Coils Hall B Wednesday 13:30-15:30 1500. A Nested Dual Frequency Birdcage/Stripline Coil for Sodium/Proton Brain Imaging at 7T Graham C. Wiggins1, Ryan Brown1, Lazar Fleysher1, Bei Zhang1, Bernd Stoeckel2, Matilde Inglese1,3, Daniel K. Sodickson1 1Radiology, Center for Biomedical Imaging, NYU School of Medicine, New York, NY, United States; 2Siemens Medical Solutions USA Inc., New York, NY, United States; 3Neurology , NYU Medical Center, New York, NY, United States The design of a novel dual frequency coil for 7T sodium/proton brain imaging is discussed. The nested coil utilized a high-pass birdcage for sodium detection and an eight-channel stripline array for proton detection. This design showed minimal interaction between the sodium and proton coils, allowing independent tuning at both frequencies. The proton striplines partially shielded the sodium birdcage, resulting in only an 8% SNR loss compared to that of the isolated birdcage, while transmit efficiency was reduced by 20%. The proton stripline coil provided adequate sensitivity for anatomical imaging and B0 shimming. 1501. Double Tuned 31P/1H Elliptical Transceiver Phased Array for the Human Brain Studies at 7 T Nikolai I. Avdievich1, Jullie W. Pan1, Hoby P. Hetherington1 1Neurosurgery, Yale University, New Haven, CT, United States The improved SNR at 7T provides significant advantages for both 1H and X nuclei (31P, 13C etc). At 7T, transceiver phased arrays improve B1 homogeneity, transmit efficiency, and peripheral SNR compare to volume coils. Therefore, double tuned transceiver arrays may provide substantial advantages over conventional double tuned volume head coils. However, they are substantially more complicated than single tuned arrays since all coils must be decoupled at both frequencies. We have developed a 16-element (8 elements per frequency) 31P/1H 7T transceiver phased head array. The double tuned transceiver array improved both B1 homogeneity and efficiency in comparison to the TEM. 1502. Single-Input Double-Tuned Birdcage Coil with Identical B1 Field Profile for 1H and 19F Imaging Lingzhi Hu1, Frank D. Hockett1, Junjie Chen1, Gregory M. Lanza1, Samuel A. Wickline1 1Washington University School of Medicine, St. Louis, MO, United States Based on coupled-resonator model, we have designed a single-input double-tuned birdcage working at both 1H and 19F frequencies on 4.7T MRI scanner. The good matching property and homogeneity of B1 field have been testified by S11 and S21 measurement and in vivo demonstration. To achieve the highest sensitivity, we have also integrated an active decoupled surface coil with the double-tuned birdcage and increased the local SNR by over 10 folds. As the standard birdcage structure is preserved, the sensitivity profile of this new double-tuned birdcage is inherently identical at 1H and 19F resonant frequencies. 1503. High SNR Dual Tuned Sodium/Proton Knee Coil Ronald D. Watkins1, Ernesto Staroswiecki1,2, Neal Bangerter3, Brian Hargreaves1, Garry Gold1 1Radiology, Stanford University, Stanford, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States; 3Electrical and Computer Engineering, Brigham Young University, Provo, UT, United States Preliminary results from a dual tuned 23Na sodium 1H proton knee coil are presented. A multiple ring birdcage design has been employed providing high sensitivity and uniformity to both nuclei without the need for frequency traps. Both coil sections are circularly polarized quadrature coils with direct drive cable connections. Cables are routed to a common potential node avoiding the need for baluns and avoiding parasitic cable loops. Registered images are presented for both sodium and proton acquisitions, avoiding the need to change the RF coil during the study Sergei Obruchkov1, Kenneth Bradshaw2, Michael D. Noseworthy3 1Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, Canada; 2Sentinelle Medical, Toronto, ON, Canada; 3Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada Dual tuned surface coil (31P and 1H) was designed and build to have high performance parameters for both channels. The coil was build to integrate into a Sentinelle Vanguard table for 3T Signa GE system. The ability to transmit on both channels simultaneously makes it possible to perform decoupling using the same coil. 1H imaging and 31P spectroscopy was demonstrated on the above coil. Brock Peterson1, Ron Watkins2, Glen Morrell3, Steven Allen4, Danny Park1, Josh Kaggie5, Garry E. Gold2, Neal K. Bangerter1 1Department of Electrical & Computer Engineering, Brigham Young University, Provo, UT, United States; 2Department of Radiology, Stanford University, Stanford, CA, United States; 3Department of Radiology, University of Utah, Salt Lake City, UT, United States; 4Department of Physics, Brigham Young University, Provo, UT, United States; 5Department of Physics, University of Utah, Salt Lake City, UT, United States Recent improvements in MRI sequences and hardware have renewed interest in sodium MRI. Dual-tuned coils are highly desirable to allow inclusion of a sodium exam during a standard proton scan without moving the patient, and to allow accurate registration of sodium and proton images. Unfortunately, many dual-tuned coil configurations come with a significant penalty in SNR performance. In this work, we evaluate the sodium SNR performance penalty and B1 homogeneity associated with a hybrid low-pass sodium, high-pass hydrogen dual-resonant birdcage design. We show that the addition of the high-pass hydrogen structure has a negligible effect on both sodium SNR performance and B1 homogeneity. Friedrich Wetterling1, Ute Molkenthin2, Sven Junge2, Andrew John Fagan3 1School of Physics, Trinity College Dublin, Dublin, Ireland; 2Bruker BioSpin GmbH, Ettlingen, Germany; 3Centre for Advanced Medical Imaging, St. Jamess Hospital, Dublin, Ireland The aim of this study was to develop a 23Na two-element phased array as part of a double-tuned 23Na/1H resonator system to maximize the 23Na SNR and acquire 23Na-Magnetic Resonance Microscopy (23Na-MRM) images together with high resolution anatomical 1H MRM images without the need to change the coil system during the experiment. The coil element decoupling was optimized by using two-winding detector elements - a novel approach to improve detector element decoupling in noise-matched phased array designs. An SNR improvement of 25 % in favour of the phased array coil was measured at a depth of 12 mm compared to a transceiver surface coil, which most likely derived from the better detector element decoupling. Novel Coils & Techniques Hall B Thursday 13:30-15:30 Adnan Trakic1, Hua Wang1, Ewald Weber1, Bing Keong Li1, Michael Poole1, Feng Liu1, Stuart Crozier1 1The School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, QLD, Australia While mechanically rotating a RF coil about an object being imaged brings a number of hardware advantages as was shown in recent studies, the approach violates the time-invariant definition of the Fourier Transform. This work presents Time Division Multiplexed - Sensitivity Encoding (TDM-SENSE) as a new alias-free image reconstruction and scan time acceleration scheme dedicated to the rotating RF coil (RRFC). In this initial study, two-fold scan time reduction was achieved by increasing the signal sampling rate and the angular frequency of coil rotation. William Dominguez-Viqueira1,2, Marc Carias2, Giles E. Santyr2,3 1Imaging Laboratories, Robarts Research Institute, London, Ontario, Canada; 2Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 3Department of Medical Imaging, University of Western Ontario, London, Ontario, Canada SNR at low magnetic field strength can be improved by reducing RF coil noise using Litz wire coils. In this work the number of turns was optimized for Litz wire coils for low field hyperpolarized noble gas imaging of rat lungs. The comparison was conducted at 0.866 MHz and 2.385 MHz corresponding to Larmor frequencies of 129Xe and 3He at 73.5 mT. The quality factors and the signal to noise ratio (SNR) for each coil at each frequency were measured. Results demonstrate the advantages of multiturn Litz wire coils obtaining up to 300% improvement compared to copper coils. 1509. The Intrinsic Magnetic Field Symmetries of the Spiral Birdcage Coil Christopher P. Bidinosti1, Chen-Yi Liu1, Scott B. King2 1Physics, University of Winnipeg, Winnipeg, Manitoba, Canada; 2Institute for Biodiagnostics, National Research Council of Canada, Winnipeg, Manitoba, Canada Spiral birdcage coils have been used for transmit array spatial encoding (TRASE) as well as for partially correcting central image brightening. A Fourier transform method usually employed for designing wire-wound shim, gradient and low frequency RF coils is used here to analyze the magnetic field symmetries of the spiral birdcage coil. Results show that twisting leads to a strong, intrinsic radial dependence in all magnetic field components. This knowledge will guide the optimization of coils used for TRASE, and may also lead to a more direct correction scheme for the problem of central brightening that occurs in high field MRI. 1510. Inductive Coupled Local TX Coil Design Weidong Wang1, Xue Lian Lu2, Jun You2, Weijun Zhang2, Haining Wang2, Helmut Greim3, Markus Vester3, Jianmin Wang2 1Siemens Mindit Magnetic Resonance Ltd , Shen Zhen, Guang Dong, China; 2Siemens Mindit Magnetic Resonance Ltd, Shen Zhen, Guang Dong, China; 3Siemens Medical Solutions Magnetic Resonance, Erlangen, Germany A Transmit/Receive coil provides several advantages compared to receive only coils. On the other hand the local TX/RX option is not always available due to cost considerations. In this paper we present a novel method to implement a local TX/RX function with an inductive coupled TX local coil.
1511. Improving B1+ Uniformity at 3T Using Optimized Spiral Birdcage Phase Gradient RF Coils Scott B. King1, Chen-Yi Liu2, Vyacheslav Volotovskyy1, Christopher P. Bidinosti2, Krzysztof Jasinski3, Mike J. Smith1, Jonathan C. Sharp4, Boguslaw Tomanek4 1Institute for Biodiagnostics, National Research Council of Canada, Winnipeg, Manitoba, Canada; 2Department of Physics, University of Winnipeg, Winnipeg, Manitoba, Canada; 3Department of Magnetic Resonance Imaging, Polish Academy of Sciences, H. Niewodniczanski Institute of Nuclear Physics, Krakow, Poland; 4Institute for Biodiagnostics (West), National Research Council of Canada, Calgary, Alberta, Canada Due to RF wave behavior and sample interaction at high B0 fields, B1+ shimming aiming at uniform excitation is important for improved SNR and image uniformity, while avoiding complicated 2D spatially selective RF methods. Using a single transmit channel at 3T we have demonstrated that an asymmetric variable pitch spiral birdcage with one end domed can be an effective method of B1+ shimming, enabling a more uniform B1+ field distribution. New RF-only MRI methods could benefit from such uniform B1+ phase gradients. Furthermore, these optimized current distributions may provide insight into building blocks for Tx-array element designs. 1512. An Inductively-Coupled Coil Designed for Clinical Use with a Limb-Positioning Platform Marc Rea1, Haytham Elhawary2, Zion Tsz Ho Tse2, Donald McRobbie1, Michael Lampérth3, Ian Young4 1Radiological Sciences Unit, Imperial College London, London, UK, United Kingdom; 2Brigham Womens Hospital, Boston, United States; 3Mechanical Engineering, Imperial College London; 4Electrical Engineering, Imperial College London, London, United Kingdom An RF receive coil was developed for use with a limb-positioning platform. The coil uses two elements placed at a fixed distance on either side of the limb and normalises signal levels through rotations of the limb. The coil uses inductive coupling and a single receiver channel. Initial results with a phantom and a volunteer show the coil has good uniformity compared with a standard flex coil. 1513. A Twin-Head Coil for Studying Two Brain Interaction with FMRI Ray F. Lee1, Weiming Dai1, Gary Drozd1, James Coan2, John Mugler, III3 1Neuroscience Institute, Princeton University, Princeton, NJ, United States; 2Psychology, University of Virginia, Chalottesville, VA, United States; 3Radiology, University of Virginia, Chalottesville, VA, United States One of the major functions of the human brain is to mediate interactions with other people. Until recently, studying brain social interactions has not been possible due to the lack of measurable methods to observe two interacting minds simultaneously. We have developed a novel twin-head MRI coil that can scan two subjects brains simultaneously while the subjects are socially interacting in one MRI scanner. Meanwhile, an even-odd mode scheme for decoupling two quadrature coils (not surface coils) is validated. 1514. Efficiency of Single-Loop and Quadrature Surface RF Coils in the Human Brain at 9.4 Tesla Dinesh K. Deelchand1, Gregor Adriany1, Can Akgun1, Kamil Ugurbil1, Pierre-Gilles Henry1, Pierre-Francois Van de Moortele1 1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States Single-loop and quadrature surface RF coils are often used for NMR spectroscopy since higher signal-to-noise ratio can be achieved in comparison to single channel volume coils. This study shows that single-loop coils are inefficient for human brain spectroscopy studies at 9.4 Tesla because the areas of high values in transmit and receive B1 fields do not overlap in space. On the other hand, quadrature surface coils can still be used as long as the phase between the two coil elements is optimized for a given region-of-interest in order to increase the B1 transmit efficiency. Sukhoon Oh1, Nikolai I. Avdievich2, Hoby P. Hetherington2, Christopher M. Collins1 1PSU College of Medicine, Hershey, PA, United States; 2Neurosurgery, Yale University, New Haven, CT, United States Here we present simulated and experimental results combining an array of counter rotating current (CRC) surface coils and a TEM volume coil in transmission. The combination provides better homogeneity than the TEM alone for excitation, and simulated results are in good agreement with experiment for combining a 4-element array with the TEM. Further simulation shows a much improved result for increasing the number of CRC coils in the array to 8. 1516. Numerical and Experimental Analysis and Demonstration of a Wire Medium Collimator for MRI Xavier Radu1, Alexander Raaijmakers2, Astrid L. van Lier2, christophe Craeye3, Cornelis A. van den Berg2 1Laboratoire de Télécommunications et Télédétection, Université catholique de Louvain , Louvain, Belgium; 2Dept. of Radiotherapy, Imaging Division, Utrecht, Netherlands; 3Laboratoire de Télécommunications et Télédétection, Université catholique de Louvain, Louvain, Belgium In this study we propose to use a metamaterial wire medium for the collimation and transfer of RF transmit and receive field from the source region to a distant location. The use of a such parallel wire medium in MRI opens several prospects: (i) the possibility to design more reliable endoscopic sensors; (ii) the possibility to create a flexible transmit configuration to excite particular regions with good homogeneity. Hereafter, the properties of wire media are investigated both numerically and experimentally. We show experimentally at 3 and 7T that the collimation and transfer can be very efficient. 1517. New Approaches of Rf Coil and Gamma Ray Radiation Shielding Assembly for Spect/Mri System SeungHoon Ha1, Mark Jason Hamamura1, Werner W. Roeck1, Lutfi Tugan Muftuler1, Orhan Nalcioglu1 1University of California Irvine, Irvine, CA, United States Several studies have reported on the design considerations of an MR compatible nuclear detector for combined SPECT/MRI. In this study, we proposed a new RF coil and „ć-ray radiation shields assembly to retain the tremendous potential of SPECT/MRI to provide high sensitivity and specificity while minimizing the interference between the MRI and SPECT systems. The results demonstrated the new assembly is superoir to configuration of a conventioncal RF coil and „ć-ray radiation shield. 1518. Understanding Parallel Transmit Array Efficiency Yudong Zhu1, Cem Deniz1, Leeor Alon1, Hans-Peter Fautz2, Daniel Sodickson1 1New York University School of Medicine, New York, United States; 2Siemens, Erlangen, Germany The efficiency of a conventional transmit coil is commonly evaluated based on amplitude of the created B1 field or spin flip angle given a certain input power. However it is not yet clear how the efficiency of a transmit array could be evaluated. This may be attributed to the shear number of possible weighting configurations (induced statically by B1 shimming coefficients or dynamically by parallel RF pulses) in driving individual Tx channels or ports. We hereby present an efficiency metric that is an extension of the conventional efficiency metric, and is as practical to quantify as is the conventional metric. 1519. B1 Shimming with a Standard 2 Channel Headcoil at 7T: Possibilities & Limitations Hans Hoogduin1, Astrid van Lier, Hugo Kroeze, Dennis Klomp, Peter Luijten, Cat van den Berg 1University Medical Center Utrecht, Utrecht, Netherlands The possibility of B1 shimming with a standard 2 channel headcoil at 7T is investigated. Both simulations and in vivo results are presented. The results show that whole brain uniformity in B1+ is not possible with two channels. However, considerable improvements can be made as illustrated by a 3D magnetization prepared FLAIR acquisition. Decoupling, Feeding & Tuning Hall B Monday 14:00-16:00 1520. Balanced Microstrip Feeds Arthur W. Magill1,2, Benoit Schaller1, Rolf Gruetter1,3 1LIFMET, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 2Radiology, University of Lausanne, Lausanne, Switzerland; 3Radiology, University of Geneva, Geneva, Switzerland Two novel balanced feed designs for microstrip array elements are introduced. Balanced capacitive matching is the symmetric version of classic single ended feeding, connected across both strip ends. Balanced geometric matching uses the fact that a resonant microstrip is purely resistive at all points along its length, connecting directly at the match points. Feeds are modeled using odd-mode analysis and design equations presented. Balanced feeds are then compared to classic single-ended feeding using simulation (FDTD) and bench measurements at 300MHz. Balanced feeding was found to offer greater stability under variable loading conditions and reduced electric field production. 1521. A Composite Decoupling Method for RF Transceiver Array Coils in MRI Yunsuo Duan1, Bradley S. Peterson1, Feng Liu2, Alayar Kangarlu3 1MRI Research, Department of Psychiatry, NYSPI & Columbia University, New York, NY 10032, United States; 2MRI Research, Department of Psychiatry,, NYSPI & Columbia University, New York, NY 10032, United States; 3MRI Research, Department of Psychiatry, NYSPI & Columbia University,, New York, NY 10032, United States We present a composite scheme for minimizing the mutual inductance of transceiver array coils with more than two channels, which combines a novel shielding-based decoupling design with simplified capacitive decoupling method. The significant advantage of this composite strategy is that the adjustment of decoupling parameters for each coil element barely affects other elements. This characteristic of the new strategy greatly minimizes the coupling mechanism between different elements which is inherent to coil arrays and thereby simplifying the complex decoupling of transceiver array coils. Desmond Teck Beng Yeo1, Eric Fiveland1, Randy Giaquinto1, Tingting Song2, Xing Yang2, Keith Park1, Adam B. Kerr3, Xu Chu2, Ileana Hancu1 1GE Global Research, Niskayuna, NY, United States; 2GE Global Research, Shanghai, China; 3Department of Electrical Engineering, Stanford University, Stanford, CA, United States Inter-element inductive coupling presents an important challenge in parallel transmit coil arrays. An ultra-low output impedance RF amplifier (RFPA) was previously introduced to address this issue. In this work, the improvements in transmit decoupling between the ultra-low output impedance RFPAs and conventional RFPAs under different loading conditions were investigated with two types of coil arrays. Bench tests and imaging studies performed on a 3T MR scanner with 8-channel transmit and receive flat array and cylindrical coils showed improved inter-element transmit decoupling, and, strong correlation between image-based B1+ decoupling measures and inter-element scattering parameters (S21). 1523. Using Piezoelectric Actuators for Remote Tuning of Transmit Coils Carl J. Snyder1, Lance DelaBarre1, Jinfeng Tian1, Can Akgun1, J. Thomas Vaughan1 1University of Minnesota, Minneapolis, MN, United States This study examines the use of piezoelectric actuators in concert with variable capacitors to allow remote tuning of transmit elements. Tuning can be performed on a subject while in the magnet and can be periodically monitored throughout the study. Gradient Coil Design Hall B Tuesday 13:30-15:30 1524. Minimax Current Density Coil Design Michael Stephen Poole1, Pierre Weiss2, Hector Sanchez Lopez1, Michael Ng3, Stuart Crozier1 1School of Information Technology and Electrical Engineering, University of Queensland, Brisbane, QLD, Australia; 2Institut de Mathematiques, Universite Paul Sabatier Toulouse 3, Toulouse, France; 3Department of Mathematics, Hong Kong Baptist University, Kowloon Tong, Hong Kong Gradient and shim coils designed with minimum power or stored energy can possess regions of high current density. The maximum current density is included in the coil design process in this study to produce minimax current coils. These coils exhibit maximally spread wire patterns, reduced peak temperature and maximum efficiency for a given coil surface. An increase in inductance/resistance is observed for coils with considerably reduced maximum current density. Silke Maria Lechner1,2, Mika W. Vogel1, Bruce C. Amm3, Timothy J. Hollis4, Hans-Joachim Bungartz2 1GE Global Research Europe, Garching, Germany; 2Technische Universität München, Garching, Germany; 3GE Global Research, Niskayuna, NY, United States; 4GE Medical Systems, Oxford, United Kingdom In magnetic resonance (MR), fast and high-resolution imaging require strong and fast switching gradients. The design of this new gradient coil generation is challenging in terms of field non-linearity and induced field distortions resulting in image artifacts. This work introduces a simulation environment that extends and integrates existing simulation tools by including gradient designs within predictive image quality assessment software. To demonstrate the capabilities of this new environment, a three-axis uniplanar flat gradient set is modeled. Realistic model simplifications as well as magnetostatic evaluations and first application simulations are presented here to increase computational speed and to verify the model. 1526. Wrapped Edge Gradient Coil for Mri-Pet Animal Imaging Viktor Vegh1, Quang M. Tieng2 1Centre for Advanced Imaging, University of Queensland, Brisbane, Queensland, Australia; 2Centre for Magnetic Resonance, University of Queensland, Brisbane, Queensland, Australia There is an increasing need to design and build systems that are capable of acquiring different modality medical images. This work describes a method of simulation of gradient coils which are appropriate for use in PET-MRI scanners. The proposed gradient coil with a gap in the middle has windings wrapped into the transverse plane at the edges for improved gradient fields. The design is developed for animal scanners with an inner bore size of 40cm. The gradient coil winding pattern, magnetic field produced and error in the gradient magnetic field are provided to establish quality of design. 1527. Characterisation of a PatLoc Gradient Coil Anna Masako Welz1, Daniel Gallichan1, Christian Cocosco1, Rajesh Kumar2, Feng Jia2, Jeff Snyder1, Andrew Dewdney3, Jan Korvink2,4, Jürgen Hennig1, Maxim Zaitsev1 1Dept. of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Baden-Württemberg, Germany; 2Dept. of Microsystems Engineering IMTEK, University of Freiburg, Freiburg, Germany; 3Siemens Healthcare, Erlangen, Germany; 44Freiburg Institute of Advanced Studies (FRIAS), University Freiburg, Freiburg, Germany The proposed and self-build PatLoc gradient coil needs special characterisation to support and improve the quality of the images acquired with this gradient coil. Focusing on image acquisition, frequency shifts arising from eddy currents and concomitant fields were assessed and evaluated. Frequency drifts of around 0.1HZ from eddy currents and up to 300Hz from concomitant fields were observed. With encoding fields of around 3*105 Hz, both effects are negligible for most imaging applications. 1528. Fast Optimization Method for General Surface Gradient Coil Design Feng Jia1, Zhenyu Liu2, Jan G. Korvink1,3 1Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany; 2Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences,, Changchun, China; 3Freiburg Institute of Advanced Studies (FRIAS), University of Freiburg, Freiburg, Germany In this paper, we present an efficient numerical iterative optimization method for designing linear gradient coil on a current-carrying surface. Using the scalar stream function as design variable, the value of the magnetic field inside a computational domain is calculated using the least square finite element method. The first-order sensitivity is calculated using the adjoint equation method. The detailed numerical optimization skills are discussed in order to obtain a fast and effective optimization procedure. Numerical examples demonstrate that this method can be used to design a gradient coil on any surface. Dustin Wesley Haw1, Brain Dalrymple1, Frank Van Sas1, Timothy James Scholl1, Blaine Alexander Chronik1 1Department of Physics and Astronomy, University of Western Ontario, London, Ontario, Canada Virtually all applications in MR require the rapid switching of gradient fields within the scanner, and many emerging applications take advantage of rapidly switched shim coils; eddy-currents generated in the system are therefore a constant challenge. The construction tolerances required for these shielded systems are not well known. Our goal is to examine the eddy-currents generated by driving a special shielded insert gradient coil of our own design. We present initial results with this test system for the impedance of the shielded gradient insert as a function of shield positioning error, both inside and outside an idealized scanner bore. 1530. Optimization of Insert Gradient Coils for Highly Localized Diffusion-Weighting Rebecca E. Feldman1, William Handler2, Blaine A. Chronik2 1Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 2Physics and Astronomy, University of Western Ontario, London, Ontario, Canada Localized gradients can deliver high gradient strengths and slew rates due to both increased gradient efficiency and elevated nerve stimulation thresholds. Gradients in diffusion-weighted imaging play two distinct roles. A gradient with a large linear range is required for imaging. However, for the diffusion weighting the gradient is only required to be strong. This abstract details the optimization for a diffusion-only gradient intended to be used as a fourth axis in addition to the three standard whole-body imaging gradients. Non-cylindrical and planar designs are considered. Using non-traditional designs, and a relaxed linearity constraint, exceptionally strong gradients can be designed. Shims & Field Correction Hall B Wednesday 13:30-15:30 1531. Transient Eddy Current Simulation of a Uni-Planar Gradient Set Silke Maria Lechner1,2, Timothy J. Hollis3, Hans-Joachim Bungartz2, Bruce C. Amm4, Guido Kudielka1, Mika W. Vogel1 1GE Global Research Europe, Garching, Germany; 2Technische Universität München, Garching, Germany; 3GE Medical Systems, Oxford, United Kingdom; 4GE Global Research, Niskayuna, NY, United States The use of computer assisted magnetic resonance imaging simulation strongly supports the design of new gradient hardware as it allows the prediction of gradient non-linearity or other distortion sources on image quality. This work utilizes finite element method simulations of a uni-planar gradient set to analyze and visualize the created transient eddy currents. Therefore, typical eddy current origins, such as thermal shield and cryostat, but also the included cooling tubes of the planar gradient set are investigated. Eddy current amplitudes and timing constants are presented for aluminum, stainless steel and copper, where interestingly, the eddy currents induced in copper cooling tubes are as strong as the induced currents in the warm bore. 1532. Design and Implementation of a Real Time Multi-Coil Amplifier System Terry W. Nixon1, Christoph Juchem1, Scott McIntyre1, Douglas Lawrence Rothman1, Robin A. de Graaf1 1MR Research Center, Yale University, New Haven, CT, United States A custom Multi Coil Amplifier System (MCAS) was designed and built to drive an array of small electrical coils which are independent of the scanners shim and gradient coils. The system was designed to have up to 96, independent +/- 1A constant current channels. A controller was developed to interface between a host computer and the constant current amplifiers. The controller has independent memory for each channel and was interfaced to the spectrometers pulse programmer to allow rapid amplitude changes enabling both static and dynamic applications. Joshua Kaggie1,2, Seong-Eun Kim2, Dennis L. Parker2, K Craig Goodrich2, Rock Hadley2 1Physics, University of Utah, Salt Lake City, UT, United States; 2Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States Diffusion Weighted Imaging (DWI) susceptibility artifacts are reduced by combining an in-house gradient coil with the system gradient coil to form a composite gradient (CG) system with increased slew rates and gradient field strength. A shielded endcap birdcage coil was developed for the CG system. A human brain was imaged using a 2D ss-EPI sequence. The resulting phase encoding bandwidth was 6.25 Hz with the system gradients and 12.2 Hz with the CG, resulting in smaller susceptibility artifacts in human brain images acquired with the composite system. 1534. Magnetic Field Modeling with a Set of Electrical Coils Christoph Juchem1, Terrence W. Nixon1, Scott McIntyre1, Douglas L. Rothman1, Robin A. de Graaf1 1MR Research Center, Yale University, New Haven, CT, United States The theoretical and experimental generation of linear magnetic field gradients as well as more complex magnetic field distributions (e.g. X2-Y2, Z2, Z2X) with a set of 24 circular, localized coils is presented. Gradients as being generated with the multi-coil approach allowed radial imaging of a mouse head. The multi-coil approach allows a flexible trade-off between accuracy and strength of the generated fields. Furthermore, the parameters are readily optimized for the specific object and volume-of-interest under investigation. 1535. Multi-Coil Shimming of the Mouse Brain at 9.4 Tesla Christoph Juchem1, Peter B. Brown1, Terrence W. Nixon1, Scott McIntyre1, Douglas L. Rothman1, Robin A. de Graaf1 1MR Research Center, Yale University, New Haven, CT, United States The first experimental realization of the multi-coil concept allowed improved shimming of the mouse brain at 9.4 Tesla. The field shapes that can be generated with a set of circular, electrical coils are shown to be much better suited to compensate for the multitude of strong, localized and complex magnetic field distortions apparent in the mouse brain than the conventional, low order spherical harmonic functions used so far. 1536. A Method for Characterizing the Magnetic Field Response of a Gradient System Signe Johanna Vannesjö1, Maximilian Häberlin1, Lars Kasper1, Christoph Barmet1, Klaas Paul Pruessmann1 1Institute for Biomedical Engineering, ETH and University Zürich, Zürich, Switzerland MRI relies on dynamic linear gradients for signal encoding, but the realization of given gradient time-courses is usually imperfect due to physical limitations. To characterize the magnetic field response to gradient-channel inputs the system is here treated as a linear time-invariant system that can be fully described by its impulse response functions. The field response was measured up to 3rd order in space with a dynamic field camera, consisting of 16 NMR probes. The measured impulse response functions allowed for accurate prediction of actual k-space trajectories and also showed predictable higher-order effects. 1537. Magnetic Field Gradient Waveform Monitor (MFGM) Hui Han1, Bruce J. Balcom 1UNB, Fredericton, N.B, Canada Numerous methods have been developed to measure MRI gradient waveforms and k-space trajectories for correcting the remaining hardware imperfections. The most widely used method to characterize eddy currents behavior is a slice selection method by Duyn. The most promising new strategy appears to be magnetic field monitoring (MFM) with RF microprobes. The new concept, pure phase encode magnetic field gradient monitor (MFGM), was recently proposed by us to solve four critical problems related to the above two methods 1538. Frequency-Division Multiplexing for Concurrent Imaging and Field Monitoring Matteo Pavan1, Signe Johanna Vannesjö1, Christoph Barmet1, David Brunner1, Klaas Paul Pruessmann1 1ETH Zurich, Zurich, Switzerland Frequency Division Multiplexing has been used from engineers since a long time to carry different signals in the same transmission line. The method consists to add signals with non-overlapping frequencies content to each other. Each signal can be fully recovered with passband filtering. In this work we use this technique to acquire in the same spectrometer channel both image information and magnetic-field-monitoring information. The image can be eventually reconstructed taking into account the actual measured magnetic field dynamic. Magnetic field monitoring is performed measuring the phase information in four fluorine probe; with this method additional channels are not need. Masaki Sekino1, Akihisa Miyazoe1, Hiroyuki Ohsaki1, Tatsuhiro Hisatsune1, Osamu Ozaki2, Tsukasa Kiyoshi3, Hitoshi Wada3 1The University of Tokyo, Kashiwa, Japan; 2Kobe Steel Ltd., Kobe, Japan; 3National Institute for Materials Science, Tsukuba, Japan MRI requires a highly homogenous magnetic field zone which usually appears at the center of the MRI magnet coil. If this homogeneous zone is allowed to occur at an off-center position along the coil axis, the patient has a wide field of vision to carry out drawing or other interesting tasks for fMRI. In order to examine this idea, we fabricated a model magnet consisting of seven NbTi coils and generating a vertical magnetic field of 0.77 T; coil outer diameter is 307 mm, coil length 191 mm, designed field homogeneity 5 ppm @ 35mm DSV, and the location of homogeneous field zone 29.4 mm off-centered along the vertical coil axis. 1540. Software Compensation of Eddy Current Fields in Higher Order Dynamic Shimming Saikat Sengupta1,2, Brian E. Welch, 1,3, Adam Anderson1,4, John Gore1,4, Malcolm J. Avison1,4 1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States; 2Biomedical Engineering, Vanderbilt University, Nashville, TN, United States; 3Philips Healthcare,, Cleveland, OH, United States; 4Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States We present a novel method of eddy current compensation for higher order shim induced eddy currents in a multislice Dynamic Shimming (DS) experiment, without the use of extra hardware. This method is based on an assumption of reaching an eddy field steady state during a fast field echo (FFE) acquisition. Using calibration scans, we characterize eddy field interactions between any two shims in terms of correction factor vectors that remain invariant with sample and shim values, for a given time between shim switches. These factors are then used to prospectively compensate for expected eddy fields in any FFE DS experiment. Mohan Jayatilake1, Judd Storrs2, Jing-Huei Lee2 1Department of Physics and Center for Imaging Research, University of Cincinnati, Cincinnati, OH, United States; 2Department of Biomedical Engineering and Center for Imaging Research, University of Cincinnati, Cincinnati, OH, United States Magnetic susceptibility variation can lead to B0 field inhomogeneity and cause artifacts including signal dropout and image distortions. Simulated and experimental studies showed that the correction for magnetic field at orbitofrontal cortex (OFC) area required shims with third and higher orders, which are not practically implemented. We propose a novel localized passive shim technique with the use of combined diamagnetic and para/ferromagnetic material to improve the field homogeneity within subjects brains, particularly in the OFC.
1542. A Single-Channel Planar Shim Coil for a Permanent Magnet Ryosuke Shigeki1, Katsumi Kose1 1Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan A single-channel planar shim coil for a permanent magnet was developed using the target field approach. The winding pattern for the shim coil was calculated for a 1.0 T permanent magnet using the magnetic field inhomogeneity measured with a 3D lattice phantom. The designed shim coil improved the magnetic field homogeneity by about 5 times, which demonstrated the usefulness of our approach. 1543. Slice Shimming Method for Reduction of Susceptibility Artifacts with PatLoc System Hsuan-Chung Niu1, Hsiao-Wen Chung2, Teng-Yi Huang3, Fa-Hsuan Lin4,5 1Graduate Institute of Biomedical Electronic and Bioinformatics, National Taiwan University, Taipei, Taiwan; 2Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan; 3Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; 4Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; 5A. A. Martinos Center, Massachusetts General Hospital, Charlestown, MA, United States In this work, we attempt to apply the PatLoc system to achieve a better shimming and improved the field homogeneity. Specifically, we used the surface gradient coils in the 8-channel PatLoc system as the shim coils to reduce the distortion of brain echo-planar imaging. Zhipeng Cao1, Rahul Dewal1, Christopher T. Sica1, Chien-ping Kao1, Christopher M. Collins1, Qing X. Yang1 1PSU College of Medicine, Hershey, PA, United States A novel synergetic shimming strategy is proposed for compensation of high order local B0 inhomogeneities in the human brain. This approach utilizes passive shimming to compensate for high order local field inhomogeneities and active shimming to compensate for the linear components. Computer simulation results demonstrate the effectiveness of the proposed method in reduction of local field inhomogeneities in the human head, suggesting a valuable shimming method for high field MRI in human and animal studies. Systems: Other Hall B Thursday 13:30-15:30 1545. High Resolution Imaging Using a High-Field Yokeless Permanent Magnet Katsumi Kose1, Tomoyuki Haishi2 1Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan; 2MRTechnology Inc., Tsukuba, Ibaraki, Japan Temperature drift of the magnetic field of a thermally insulated yokeless permanent magnet (field strength = 1.04 T) was measured for about 68 hours. The temperature coefficient of the magnetic field was about -950 ppm/deg. The largest Larmor frequency change was about 50 Hz/min. The performance of the thermal insulation was evaluated with high resolution imaging (20~40 micron square) of several samples. The results have suggested that careful choice of the NMR lock interval and the pixel bandwidth will solve the temperature drift problem of the high field yokeless magnet.
Mihaela Jekic1, Eric L. Foster2, John Arnold3, Jacob Bender1, Subha V. Raman4, Orlando P. Simonetti5 1Biomedical Engineering, The Ohio State University, Columbus, OH, United States; 2Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States; 3Agricultural Technical Institute, The Ohio State University, Columbus, OH, United States; 4Internal Medicine, The Ohio State University, Columbus, OH, United States; 5Internal Medicine and Radiology, The Ohio State University, Columbus, OH, United States We developed a feedback control system for a fully MRI-compatible water hydraulic treadmill, and tested its performance up to the speed of 5.5 miles/hr and the incline of 11.3ŗ, corresponding to stage 6 of the standard Bruce treadmill protocol widely used in cardiac stress testing. Feedback is obtained using fiber optic sensors while the control is performed outside the MRI room using LabVIEW. In addition, we implemented several safety features to ensure the treadmill speed and elevation will remain within specified safety limits. The treadmill was found to perform accurately and safely immediately adjacent to the MRI table. Geron Andre Bindseil1, William B. Handler1, Timothy J. Scholl1, Blaine A. Chronik1 1Department of Physics and Astronomy, University of Western Ontario, London, Ontario, Canada One approach to PET/MRI is to use field-cycled (FCMRI) with a conventional PMT-based PET system. Combining PET with FCMRI would enable the use of commercially available, highly optimized PET systems with little physical modification. For this approach to be feasible, the PET detectors must experience no permanent changes in gain or efficiency after exposure to magnetic fields. The authors present results from a preliminary feasibility study testing the performance of a commercial small-animal PET system after exposure to magnetic fields. No significant permanent changes were observed in PET imaging performance. 1548. Bo Coil Designs for in Vivo Delta Relaxation Enhanced MR in Humans Chad Tyler Harris1, Jamu K. Alford1, William B. Handler1, Timothy J. Scholl1, Blaine Alexander Chronik1 1Department of Physics and Astronomy, University of Western Ontario, London, Ontario, Canada Delta relaxation enhanced magnetic resonance (dreMR) is an emerging technology that utilizes an insert electromagnet to modify the main magnetic field as a function of time in an otherwise conventional MR scanner. In this study, we investigate the design and performance of insertable electromagnets suitable for performing localized dreMR imaging in human subjects. The two particular anatomical areas of interest are the head/neck, and the prostate; however, this approach may be extended to a variety of other application areas. 1549. Low Power and High Field Strength B0 Coil: A Vision of Portable MR Wen-Yang Chiang1, Kelvin Wong1, Stephen TC Wong1 1Center for Bioengineering and Bioinformatics, The Methodist Hospital Research Institute and Department of Radiology, The Methodist Hospital, Houston, TX, United States In order to address the need of the MR coil with both high field strength and low power usage, a miniaturized B0 coil is presented. Finite element simulation showed that higher magnetic field strength was generated by a coil with sharp tip than that by a coil with blunt end. A cost effective way was introduced to fabricate this sharp tip coil. Focused magnetic field generated by the coil with a sharp tip was directly measured by a tunneling effect magnetic field sensor. This study will help in addressing the need of portable MR systems. 1550. MR Compatible Sensor for Measuring Respiratory Motion Based on Acceleration. Laure Rousselet1,2, Marina Filipovic1,2, Zhor Ramdan-Cherif1,2, Valérie Laurent, 2,3, Cédric Pasquier4, Jacques Felblinger1,2 1IADI, Nancy-Université, Nancy, France; 2U947, Inserm, Nancy, France; 3CHU de Nancy, Nancy, France; 4CIC801, INSERM, Nancy, France MR acquisitions have to be synchronized with respiration to avoid motion artifacts. Pneumatic belts are the most current tool for this purpose. However, these belts suffer from signal drifts, leaks in pneumatic system and give only an average displacement. We present a MR compatible sensor which aims at measuring the acceleration of a localized region. Accelerometer is well correlated to image-based displacement measures and gives similar results to respiratory belts. The sensor presents practical advantages: it is small, easy to position on the patient, less cumbersome than respiratory bellows and allows for local displacement estimation. Jamu K. Alford1, Timothy J. Scholl1, William B. Handler1, Blaine A. Chronik1 1Physics and Astronomy, The University of Western Ontario, London, ON, Canada Delta relaxation enhanced magnetic resonance (dreMR) is an emerging method for field-cycled MR imaging, which utilizes a removable electromagnetic coil to modify the strength of the main magnetic field during an MRI pulse sequence. This abstract describes major improvements made in a new, high-performance, second-generation dreMR system for mouse and small animal imaging. Comparisons are made between this second-generation dreMR coil and the prototype dreMR coil used in early dreMR studies. 1552. A Safe and Artefact Free Device for Monitoring Galvanic Skin Conductance During FMRI Peter Erhard1, Dieter Leibfritz1 1Dept. of Chemistry, University of Bremen, Bremen, Germany We developed a device for measuring galvanic skin response (GSR) during functional magnetic resonance imaging (fMRI). The goal was to prevent the volunteer from the risk of electric stimulation due to gradient induced currents into the leads of the device. This was achieved by inserting photo electronic switches into the leads close to the electrodes. These switches are turned off during gradient switching. As GSR data is only acquired during quiet periods, no additional filtering was implemented. First tests show efficient protection from electric stimulation. However the GSR signal is still contaminated by physiological noise and minor gradient cross talk. 1553. MR Compatible Spirometer Laure Rousselet1, Marina Filipovic1, Slavisa Jovanovic1,2, Gilles Bosser3, Cédric Pasquier4, Jacques Felblinger1 1IADI, Nancy-Université, Nancy, France; 2U947, Inserm, Nancy, France; 3Physical Medicine and Rehabilitation, University Hospital of Nancy, Nancy, France; 4CIC801, INSERM, Nancy, France MR compatible spirometer is needed for (i) monitoring of anaesthetized patient and (ii) sequence synchronization and/or image reconstruction to avoid motion artifacts. We present an MR compatible spirometer which aims at measuring patients air flow and lung volume in order to extract motion information. The proposed sensor could be connected to the respirator in order to monitor patients during MRI examination. Spirometer is well correlated to internal displacement extracted from the images series, although a time delay appears due to the external position of the sensor. Diffusion Human Brain Diseases Hall B Monday 14:00-16:00 1554. The Effect of T1-Relaxation on Tensor-Derived ADC-Maps Finn Lennartsson1,2, Bo Nordell1, Olof Flodmark2 1Karolinska University Hospital, Dept of Medical Physics, Stockholm, Sweden; 2Karolinska University Hospital, Dept of Neuroradiology, Stockholm, Sweden The T1-relaxation process is a well-known issue in diffusion-weighted magnetic resonance imaging (DWI). A typical diffusion-tensor imaging (DTI) scheme collects first the S0:s followed by gradient directions: S01,..., S0m S(r1),..., S(rn). The T1-weighting among the initial S0:s is not homogenous, giving an erroneously high baseline (mean of S0:s), which results in an overestimation of the tensor elements. T1-relaxation effects in the initial volumes of a DTI experiment have an impact on the estimation of a tensor-derived ADC-map, and the same effect is expected for non-tensor models. The effect is especially prominent in tissues with long T1 like CSF, where a overestimation of ADC is expected. 1555. Linking the Individual EEG Alpha Frequency to the Brains Fibers Andrea Federspiel1, Thomas Koenig1, Thomas Dierks1, Kay Jann1 1Psychiatric Neurophysiology, University Hospital of Psychiatry, Bern 60, Switzerland The Individual EEG alpha frequency (IAF) correlates with subjects performance in cognitive tasks. However, the functional networks and structural substrate underlying the inter-individual differences in IAF are largely unknown. Here we investigated on structural correlates in terms of white matter fiber trakts that are related to the subjects IAFs. We observed dedicated structure-function correlates in the cingulum involved in the DMN and in the arcuate fascicle associated with the left-WMN. Subjects with higher IAF tend to be faster and perform better in various cognitive tasks. Therefore, our observations suggest that structural connectivity among task relevant areas affects processing capacity. Hiroshi Kawaguchi1, Takayuki Obata1, Harumasa Takano2, Miho Ota2, Yoshihide Akine2, Hiroshi Ito2, Hiroo Ikehira1, Iwao Kanno1, Tetsuya Suhara2 1Department of Biophysics, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan; 2Department of Molecular Neuroimaging, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan Positron emission tomography with L-[β- 11C]DOPA and diffusion tensor imaging were measured on the same group of volunteers to assess the relationship between dopamine synthesis and cell-level structure in the striate body. There was a negative correlation between dopamine synthesis ratio and mean diffusivity in the left striate body, which indicates that the more water motion is restricted, the more dopamine is synthesized in the left striate body. Assuming that water motion is related to celluarity, the result suggests dopamine synthesis may depend on the density of dopaminergic neurons. Siawoosh Mohammadi1, Volkmar H. Glauche2, Simon S. Keller1, Michael Deppe1 1Department of Neurology, University of Muenster, Muenster, NRW, Germany; 2Department of Neurology, University of Freiburg, Freiburg, Germany Recent developments have enabled automated voxel-based statistical (VBS) analyses of fractional anisotropy (FA) images (FA-VBS). However, due to the lack of a gold standard the question, which spatial normalization is best for FA-VBS, is still not answered. To assess the influence of the registration on the FA-VBS results, we investigate the white matter (WM) of juvenile myoclonic epilepsy patients with a-priori known damage that correlates with the frequency of generalized tonic-clonic seizures (GTCS). To perform the registration we used the SPM-normalization toolbox. We showed that the correlation between GTCS and WM-damage was best detected if multi-contrast, iterative registration was used. Vincent Jerome Schmithorst1, Scott Kerry Holland1, Elena Plante2 1Radiology, Children's Hospital Medical Center, Cincinnati, OH, United States; 2Speech, Language, & Hearing Sciences, University of Arizona, Tucson, AZ, United States A diffusion tensor imaging (DTI) study was conducted in a cohort of normal-hearing children ages 9-11 investigating correlations of white matter microstructure with higher-order auditory processing tasks often used to diagnose auditory processing disorder (APD) in children. The more difficult tasks showed negative correlations of fractional anisotropy (FA) in the corticospinal tract with task performance, while the easiest task showed a positive correlation. Positive correlations of FA with task performance were also seen in white matter adjoining prefrontal and occipital areas for some tasks. Results support a dual-stream (dorsal and ventral) model of auditory comprehension. 1559. The Effects of HIV and Hepatitis C Infection on Diffusion Tensor Imaging Measures Huiling Peng1, Jewell Thomas1, Joseph Mettenburg2, Avi Snyder1, Tammie Benzinger2, David Clifford1, Robert Paul3, Beau Ances4 1Neurology, Washington University in St. Louis, St. Louis, MO, United States; 2Radiology, Washington University in St. Louis, St. Louis, MO, United States; 3Psychology, University of Missouri St. Louis, St. Louis, MO, United States; 4Neurology, Washington University in St. Louis, St. Louis, MO , United States Hepatitis C virus (HCV) is a frequent co-infection with HIV. Both affect brain function raising the possibility of synergistic interactions. We investigate the relationship between neurological function and white matter integrity using DTI in mono (HIV+) (n=15) vs. co-infected (HIV+/HCV+) (n=13) participants. Regions-of-interest corresponding to the cingulum and genu of the corpus callosum were selected. Co-infected participants were more impaired than mono-infected HIV+ subjects on neuropsychological testing but no significant differences were seen for DTI values. The combination of HIV and HCV co-infection affected measures within the brief neurocognitive screening but not structural neuroimaging measures. Jiųķ Keller1,2, Aaron Michael Rulseh1, Michael Syka1, Josef Vymazal1 1Nemocnice Na Homolce, Prague, Czech Republic; 23rd Faculty of Medicine, Charles University in Prague, Prague, Czech Republic We measured FA in white and gray matter regions using two different DTI sequences (12 and 30 directions) in 23 healthy adult volunteers A number of white and gray matter regions were selected including basal ganglia and corpus callosum. The gray matter results were correlated with expected iron concentration. We detected a significant correlation between age and FA for both DTI sequences in the rostrum of the corpus callosum, anterior internal capsule and the pyramidal tract. A significant difference in FA between DTI sequences was detected in the basal ganglia where correlation between iron amount and FA was found. Diffusion: White Matter Modeling Hall B Tuesday 13:30-15:30 1561. Optimized Diffusion MRI Protocols for Estimating Axon Diameter with Known Fibre Orientation Torben Schneider1, Henrik Lundell2,3, Tim B. Dyrby2, Daniel C. Alexander4, Claudia Angela Michela Wheeler-Kingshott1 1NMR Unit, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom; 2Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Copenhagen, Denmark; 3Department of Excercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark; 4Centre for Medical Image Computing, Department of Computer Science, UCL, London, United Kingdom We present a method that optimizes diffusion MRI protocols to be sensitive to axon diameter and axonal density in white matter structures with known single fibre direction. Computer simulations clearly show that our method improves accuracy of measurements compared to protocols independent of fibre orientation, especially when signal-to-noise-ratio is low. Furthemore, we generate indices of axon diameter and density from a fixated monkey spinal cord and are able to discriminate anatomically different white matter regions. Jun-Cheng Weng1,2, Wen-Yih Iascc Tseng1,3 1Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan; 2Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan; 3Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan The corpus callosum (CC) is the main fiber tract connecting bilateral cerebral hemispheres, serving information transfer and processing in various cognitive functions. In view of the topographically-specific relation between callosal regions and the connected cortical regions, several partitioning approaches have been proposed to allow separate analysis of different callosal sectors. Vertical partitions are commonly used which subdivide the CC into five regions based on fractions of its maximal anterior-posterior length as proposed by Wiltelson. These regions might be affected differently in the development of disease, and their structural parameters such as size and shape might associate with cognitive or functional tests involved in different modes of interhemispheric interactions. This study proposed a novel technique, q-planar imaging (QPI) to map the relative axonal diameters of CC in normal human brain. It was based on the Fourier relationship between probability density function (PDF) of the water molecular diffusion and sampled diffusion attenuated images in the space of spatial modulation, dubbed q-space. It provided MR images in which physical parameters of water diffusion such as the mean displacement and the probability at zero displacement of water molecules were used as image contrast. Our results demonstrated that QPI produced reasonable distribution of relative axonal diameters of CC in normal human brain. 1563. The Extracellular Diffusion Weighted Signal Predicts Axon Diameter Distribution Parameters Hubert Martinus Fonteijn1, Matt G. Hall1, Daniel C. Alexander1 1Computer Science, Centre for Medical Image Computing, London, United Kingdom The estimation of axon diameter distribution parameters remains a big challenge for diffusion-weighted imaging. Generally, only intracellular diffusion is considered to be influenced by axon diameter. Extracellular diffusion on the other hand is considered to be approximately Gaussian in the long diffusion time limit and to be independent of axon diameter. In this abstract, we perform Monte Carlo simulations of diffusion in the extracellular compartment for a wide range of diffusion times and we construct a non-parametric model of extracellular diffusion using Gaussian Process Regression. We then show that axon diameter distribution parameters can be estimated from this model. 1564. Polynomial Models of the Spatial Variation of Axon Radius in White Matter Gemma Louise Morgan1, Rexford D. Newbould2, Brandon Whitcher2, Daniel C. Alexander1 1Centre for Medical Image Computing, University College London, London, United Kingdom; 2Clinical Imaging Centre, GlaxoSmithKline, London, United Kingdom Axon radius r is a potentially useful clinical biomarker that can be derived from diffusion weighted imaging. However its estimation in a clinical setting is hampered by poor signal-to-noise ratio and limited sensitivity to small axon radii at low gradient strengths. In this study we introduce a technique for estimating a mean radius index ρ that exploits the spatial coherence of axon radii across the corpus callosum. Specifically, we fit a polynomial model of the spatial variation of ρ. This significantly reduces the total number of parameters to estimate and provides sensitivity to axon radius, even at typical clinical gradient strengths. 1565. Can AxCaliber Be Extended to Estimate Axonal Radius and Orientation at the Same Time? Jaime E. Cisternas1 1Engineering and Applied Sciences, Universidad de los Andes, Santiago, RM, Chile Diffusion tensor MRI provides biomarkers that have been shown to indicate microstructural features in the brain and other organs. These biomarkers, even though contain information about development, ageing and disease progression, lack specificity and don't give direct measures of axon density and radius. Several approaches, within the framework of diffusion weighted MR, have been proposed to extract radii, assuming previous knowledge of the orientation of the axons. In this work we extend AxCaliber, to measure axon diameter distribution along multiple orientations, and use numerical simulations to evaluate the capacity of the model to estimate radius and orientation reliably under the presence of noise. Jonathan Andrew David Farrell1,2, Bennett A. Landman3,4, Jiangyang Zhang1, Seth A. Smith5,6, Daniel S. Reich1,7, Peter A. Calabresi8, Peter C.M. van Zijl1,2 1Dept. of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2Kennedy Krieger Institute, F.M. Kirby Research Center for Functional Brain Imaging, Baltimore, MD, United States; 3Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 4Electrical Engineering, Vanderbilt University, Nashville, TN, United States; 5Dept. of Radiology, Vanderbilt University, Nashville, TN, United States; 6Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 7Neuroimmunology Branch (NINDS), National Institutes of Health, Bethesda, MD, United States; 8Dept. of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States Axonal injury can produce constrictions and enlargements (beading) of axon membranes and increase their permeability. Here we investigate the effect of these morphological parameters on diffusion properties measured with diffusion tensor and q-space imaging. Degenerating axons are modeled as the union of cylinders and spheres of varying radii. Using Monte Carlo simulations, with intra- and extra-cellular compartments, we show that beading and increased permeability can act in concert to produce increased perpendicular diffusion. However, while parallel diffusion is decreased by beading, non-Gaussian behavior is mitigated by increased permeability. This study may aid the development of contrasts specific for axonal injury. Håkan Hagslätt1,2, Markus Nilsson3, Henrik Hansson3, Jimmy Lätt1,3, Danielle van Westen1,2 1Center for Medical Imaging and Physiology, Lund University Hospital, Lund, Sweden; 2Department of Diagnostic Radiology, Lund University Hospital, Lund, Sweden; 3Department of Medical Radiation Physics, Lund University, Lund, Sweden Axons in fibre tracts may be non-straight and have an undulating, approximately sinusoidal course. It is known that axonal undulations are present in the peripheral nervous system and in some parts of the central nervous system that are subjected to strain during locomotion, for instance, the optic nerve. These undulations might affect parameters estimated using diffusion MRI, such as the fractional anisotropy. Furthermore, measurements attempting to estimate the axonal sizes might be biast towards an overestimated axonal size when undulations are present.
1568. A New Approach to Structural Integrity Assessment Based on Axial and Radial Diffusivities. Claudia Angela Michela Wheeler-Kingshott1, Olga Ciccarelli2, Torben Schneider1, Daniel C. Alexander3, Mara Cercignani4 1NMR Unit, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom; 2NMR Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom; 3Dept. Computer Science, UCL, Centre for Medical Image Computing, London, United Kingdom; 4Neuroimaging Laboratory, Fondazione Santa Lucia, Rome, Italy A new definition of projected-axial (dp-ax) and radial (dp-rad) diffusivities in standard space has been tested in multiple sclerosis and healthy subjects using VBM. For each subject, dp-ax and dp-rad are defined as the components of the diffusion tensors (DTs) along the most probable direction of healthy tracts as defined by the eigenvectors of a super-DT dataset in standard space (calculated as the average of the DTs of a reference group of healthy subjects). The results show that in a patient with moderate disability there are areas of reduced dp-ax not revealed by the principal eigenvalue of the DT. 1569. White Matter Model for Diffusional Kurtosis Imaging Els Fieremans1, Jens H. Jensen1, Ali Tabesh1, Caixia Hu1,2, Joseph A. Helpern1,2 1Radiology, New York University School of Medicine, New York, United States; 2Center for Advanced Brain Imaging, Nathan S. Kline Institute, Orangeburg, NY, United States We develop an idealized two-compartment diffusion model of white matter suitable for analysis with diffusional kurtosis imaging (DKI). The standard DKI metrics are used to derive the extracellular and axonal bare diffusion coefficients, the axonal water fraction (AWF), and tortuosity of the extra-axonal geometry, both providing information related to axonal and myelin density. Values for these parameters obtained for a healthy volunteer agree well with those of prior studies. Since a DKI dataset is acquired within a few minutes, this approach may allow for the clinical assessment of myelin associated neuropathologies, such as multiple sclerosis and Alzheimers disease. Markus Nilsson1, Håkan Hagslätt2,3, Danielle van Westen2,3, Ronnie Wirestam1, Freddy Ståhlberg1,3, Jimmy Lätt1,2 1Department of Medical Radiation Physics, Lund University, Lund, Sweden; 2Center for Medical Imaging and Physiology, Lund University Hospital, Lund, Sweden; 3Department of Diagnostic Radiology, Lund University, Lund, Sweden The axonal water exchange time was investigated in Monte Carlo simulations using impermeable myelin sheaths, but permeable nodes of Ranvier. The results showed that axonal exchange times on the sub-second were possible for short and intermediate internodal lengths (i.e. length of the myelin sheath) and high nodal permeability. This is of importance for high b-value diffusion MRI when measured with different diffusion times. Oleg P. Posnansky1, N. J. Shah2,3 1Institute of Neuroscience and Medicine - 4, Medical Imaging Physics, Forschungszentrum Juelich, GmbH, 52425 Juelich, Germany; 2Institute of Neuroscience and Medicine - 4, Medical Imaging Physics , Forschungszentrum Juelich, GmbH , 52425 Juelich, Germany; 3Deparment of Neurology, Faculty of Medicine, RWTH Aachen University, 52074 Aachen, Germany Diffusion weighted MRI is sensitive to tissue architecture on a micrometer scale. Determining whether it is possible to infer the specific mechanisms that underlie changes in the DW-MRI could lead to new diffusion contrasts specific to particular white-matter degeneration processes. We have developed a renormalization-group method in order to explore the effects of a large range of microparameters on apparent-diffusion and applied it to different kind of brain tissue tessellations. Our approach takes the influence of disorder into the consideration and it allows quantitative investigation of the sensitivity of apparent-diffusion to the variations of the dominant set of microparameters.
1572. Observation of Anisotropy at Different Length Scales in Optic and Sciatic Nerve Speciments Evren Ozarslan1, N Shemesh2, Y Cohen2, Peter J. Basser 1NIH, Bethesda, MD, United States; 2Tel Aviv University Double-PFG MR is a promising method to assess restriction induced anisotropy at different length scales enabling the extraction of information such as compartment size, shape, and orientation distribution function. In this work, we present the simultaneous characterization of the axon diameter and the dispersion in the orientation of the axons in excised optic and sciatic nerve specimens. Assuming a von Mises distribution for the orientation distribution function enabled the characterization of the dispersion of fiber orientations via the estimation of only one additional parameter. Farida Grinberg1, Yuliya Kupriyanova1, Ana-Maria Oros-Peusquens1, N Jon Shah1,2 1Medical Imaging Physics, Institute of Neuroscience and Medicine 4, Forschungszentrum Juelich GmbH, Juelich, Germany; 2Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany The propagation of water molecules in the brain and the corresponding NMR response are affected by many factors such as compartmentalization, restrictions, and anisotropy imposed by the cellular microstructure. In addition, interfacial interactions with the cell membranes and exchange play a role. Therefore, a differentiation between the various contributions to the average NMR signal in in vivo studies represents a difficult task. In this work, we have performed random-walk Monte Carlo simulations in model systems aiming at establishing the quantitative relations between the dynamics and microstructure. A detailed analysis of the average diffusion propagators and the corresponding signal attenuations is presented and the implications for experimental studies are discussed. 1574. Discovering White Matter Structure Beyond Fractional Anisotropy Maps Jakub Piatkowski1, Amos J. Storkey2, Mark E. Bastin3 1Neuroinformatics Doctoral Training Centre, University of Edinburgh, Edinburgh, United Kingdom; 2Institute for Adaptive and Neural Computation, School of Informatics, University of Edinburgh, Edinburgh, United Kingdom; 3Medical Physics, University of Edinburgh, Edinburgh, Midlothian, United Kingdom We use a fully physical two-compartment model, comprising isotropic and anisotropic terms, to describe diffusion MRI data. The posterior distributions over the parameters of this model are estimated using sampling techniques. This yields maps of white matter (WM) volume, which reveal a level of structure missing in FA maps. Additionally, we get tensor parameters for the anisotropic compartment (i.e. WM), which provide a measure of fibre-specific anisotropy that doesn't suffer from partial volume effects. Diffusion Modeling: General Hall B Wednesday 13:30-15:30 1575. The Effects of Intracellular Organelles on the ADC of Water Molecules in Cells Daniel C. Colvin1, Jerome Jourquin2, Junzhong Xu1, Mark D. Does1, Lourdes Estrada2, John C. Gore1 1Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 2Cancer Biology, Vanderbilt University, Nashville, TN, United States Diffusion-weighted MRI methods are commonly used to characterize changes in tissue structure that accompany such pathologies as stroke and cancer. However, the underlying biophysical mechanisms influencing the apparent diffusion coefficient (ADC) remain poorly understood. Temporal diffusion spectroscopy techniques, which probe diffusion times two orders of magnitude shorter than conventional pulsed gradient methods, were implemented in a study of packed human embryonic kidney cells treated with drugs that alter actin polymerization, microtubule formation, and Golgi structure. Results reveal that these techniques may provide a more sensitive probe of changes in intracellular structure compared to conventional methods. 1576. The Influence of Holmium-166 Loaded Microspheres on ADC Measurements Using DWI Gerrit Hendrik van de Maat1, Peter R. Seevinck1, Chris J.G Bakker2 1Image Sciences Institute, Utrecht, Netherlands; 2Department of Radiology, University Medical Center, Utrecht, Netherlands It was shown that the presence of HoMS attenuates the signal of diffusion weighted images leading to a ADC reduction of 0.1mm2/ms per mg/ml HoMS. The reduction of the ADC is caused by the additional gradients induced by the microspheres resulting in a additional weighting factor for calculation of the ADC which is not taken into account. The dependency of the ADC on concentration HoMS is an effect that should be considered when using DWI for evaluating tumor viability after radioembolization. Since the local concentration can range up to 15mg/ml, a potential underestimation of the ADC of 1.5mm2/ms can occur which may lead to wrong diagnostic conclusions. 1577. Influence of Brain Ischemia on Biexponential Water Diffusion MRI Signal Decay Renaud Nicolas1, Xavier Franceries1, Jeremie Pariente1, Nicolas Chauveau1, Franēois Chollet1, Pierre Celsis1 1UMR 825, INSERM; Imagerie cérébrale et handicaps neurologiques, F-31059 Toulouse, France, Metropolitan Biexponential analysis of DWI isotropic contrast in a case of acute stroke is here presented. Main finding were an F(slow) rise that has the same anatomic localization that has DWI positive signal but physiologic T. Eleftheria Panagiotaki1, Matt G. Hall1, Bernard Siow1,2, Mark F. Lythgoe2, Daniel C. Alexander1 1Centre for Medical Image Computing, Dept. of Computer Science, University College London, London, United Kingdom; 2Centre for Advanced Biomedical Imaging, University College London, London, United Kingdom This work outlines a method to construct detailed three-dimensional geometric models of tissue microstructure using confocal laser scanning microscopy (CLSM) images. We use these models to simulate the diffusion MRI signal from the tissue by running random-walk simulations within the resulting mesh. The precise simulated data from our method provide a mechanism for evaluating the quality of simple parametric models and the parameter estimates they provide. Jens H. Jensen1, Joseph A. Helpern1 1Radiology, New York University School of Medicine, New York, NY, United States The apparent diffusional kurtosis for the Kärger model is calculated as a function of the gradient pulse duration. It is found that the error relative to the true value is at most a few percent for the parameter range of interest for brain. This result helps to justify the use of larger gradient pulse durations for diffusion-weighted imaging estimation of the diffusional kurtosis. Irina Kezele1, Daniel C. Alexander2, Philip Batchelor3, Jean-Franēois Mangin1, Denis Le Bihan1, Cyril Poupon1 1NeuroSpin, CEA, Gif-sur-Yvette, France; 2University College , London, United Kingdom; 3King's College , London, United Kingdom We propose an analytic three-compartment diffusion model to explain the diffusion signal coming from tissues that are assumed to comprehend the intracellular and extracellular free water pools and a membrane-bound water pool, as hypothesized in a recent paper by Le Bihan (Phys. Med. Biol. 2007). Using this model we deliver an optimized imaging protocol to measure the relevant model parameters. Simulation experiments demonstrate the accuracy of estimating all the model parameters. In particular, the accurate estimation of membrane-water compartment size promotes the potential to detect the changes of this size that has been suggested to be related to neuronal activation. Frederik Bernd Laun1, Bram Stieltjes 1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Baden-Württemberg, Germany In DWI, the apparent diffusion coefficient is determined by both, the diffusion process and the temporal profile of the diffusion gradients. In this work a technique to determine the influence of the temporal gradient profile on the measured ADC is developed for the motional narrowing regime in closed geometries. It yields a direct series expansion in powers on inverse time. It is shown that the discontinuities and integrals over the derivatives of the gradient profile determine the constants of this series expansion. 1582. Unifying Transverse Relaxation and Diffusion: An Effective Medium Approach Dmitry S. Novikov1, Valerij G. Kiselev2 1Radiology, NYU School of Medicine, New York, NY, United States; 2Medical Physics, Diagnostic Radiology, Uniklinikum Freiburg, Freiburg, Germany MR signal is massively volume-averaged. Which parameters of tissue microstructure can survive this averaging, and be quantified by MRI? An answer is given by the effective medium description of tissues yielding the voxel-averaged equation for the magnetization. Heterogeneous diffusivity, relaxation rate and Larmor frequency offset give rise to corrections to the magnetization dynamics. The quantifiable tissue parameters are the distinct length scales on which the local diffusivity, relaxation rate and Larmor frequency vary. The effective medium approach unifies diffusion and relaxation, focussing on the single quantity whose frequency and wavevector dependence contains all measurable information about tissue heterogeneity. 1583. Estimating Model Uncertainty When Fitting Multiple B-Value Diffusion Weighted Imaging Matthew R. Orton1, David J. Collins1, Dow-Mu Koh2, Michael Germuska1, Martin O. Leach1 1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom; 2Department of Radiology, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom Many models have been proposed for describing diffusion-weighted data, but as the environment of the diffusion process is known to be very complex in biological systems, choosing an appropriate model is difficult. We present a Bayesian methodology for estimating the posterior probability (uncertainty) of a given selection of diffusion models, applied to clinical DWI data. This is of interest to indicate statistical model uncertainty, and therefore uncertainty in the interpretation of the data. By penalising over complicated models, this methodology provides diffusion metrics that are more stable, and therefore more sensitive to a wider range of treatment effects. 1584. DWI Signal from a Medium with Heterogeneous Diffusivity Dmitry S. Novikov1, Valerij G. Kiselev2 1Radiology, NYU School of Medicine, New York, NY, United States; 2Medical Physics, Diagnostic Radiology, Uniklinikum Freiburg, Freiburg, Germany We consider the DWI signal from any medium (tissue) in which the diffusion coefficient varies in space. Using recently developed effective-medium approach, we relate the signal to the diffusivity correlation function. Explicit formulas for time-dependent diffusion coefficient and diffusional kurtosis are provided in the case when the local diffusivity varies on a well-defined length scale. Our results are numerically confirmed by the Monte-Carlo simulation of diffusion in a two-dimensional model tissue. While the DWI signal has an approximately biexponential form, it is shown to be qualitatively different from that of the two-compartment exchange (Kärger) model. 1585. From Single- To Double-PFG: Gleaning New Microstructural Information in Complex Specimens Noam Shemesh1, Evren Özarslan2, Peter J. Basser2, Yoram Cohen1 1School of Chemistry, Tel Aviv University, Tel Aviv, Israel; 2Section on Tissue Biophysics and Biomimetics, NICHD, National Institutes of Health, Bethesda, MD, United States Although single-pulsed-field-gradient (s-PFG) methodologies such as DTI and the q-space approach are widely used to probe tissue microstructures, they suffer from inherent limitations, especially when specimens are characterized by randomly oriented compartments or size distributions. The double-PFG (d-PFG) is emerging as a new probe for novel microstructural information that cannot be achieved by other means. Here we demonstrate that d-PFG can be used to extract accurate compartment dimensions at low q-values both in phantoms and in biological cells which are randomly oriented, and in optic and sciatic nerves. The d-PFG may become an important MRI method in the CNS. 1586. New Quantitative Indices for DWI of the Brain Tissue at High B-Values Farida Grinberg1, Ezequiel A. Farrher1, Joachim Kaffanke1, Ana-Maria Oros-Peusquens1, N. Jon Jon Shah1,2 1Medical Imaging Physics, Institute of Neuroscience and Medicine 4, Forschungszentrum Juelich GmbH, Juelich, Germany; 2Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany Diffusion MRI permits non-invasive probing of tissue microstructure and function and provides invaluable information in brain diagnostics. Conventional methods, however, are designed to retrieve only the average diffusion characteristics and tend to ignore deviations from simple Gaussian behaviour. Recently, increasing efforts have been dedicated to the development of the advanced approaches capable of capturing more detailed information on the propagation mechanisms. In this work, we report an in vivo diffusion study of the brain based on a detailed analysis of the attenuation patterns. New quantitative indices are suggested as map parameters and their potential use with respect to studies of the brain is discussed. Aurobrata Ghosh1, Evren Özarslan2, Rachid Deriche3 1Project Team Odyssée, INRIA Sophia Antipolis - Méditerannée, Sophia Antipolis , Alpes Maritimes, France; 2Section on Tissue Biophysics and Biomimetics, NICHD, National Institutes of Health, Bethesda, MD, United States; 3INRIA Sophia Antipolis - Méditerannée, rachid.deriche@sophia.inria.fr, Sophia Antipolis, Alpes Maritimes, France We validate the GDTI with Gram-Charlier series approximation of the propagator approach in 1D, by comparing the Gram-Charlier and the Edgeworth series on closed form diffusion propagators with known cumulants. We also compare against estimated cumulants. We conclude that the Edgeworth series outperforms the Gram-Charlier series when the cumulants are known, but estimating the cumulants from the signal is numerically an important and sensitive problem. 1588. Detecting Restriction Using Non-Parametric Modelling of Diffusion MR Data Saad Jbabdi1, Karla Laureen Miller1, Adrian R. Groves 1FMRIB Centre, University of Oxford, Oxford, United Kingdom There is a growing interest in biophysical mechanisms for the diffusion contrast, with the exciting perspective of quantifying brain tissue microstructure (e.g. axon size and density). In particular, modelling restriction effects in the signal allows us to estimate the size of restricting structures. It is not clear, however, to what extent the signal acquired in vivo is sensitive to restriction. We suggest a non-parametric approach (no biophysical model assumed) to quantify restriction effects in the diffusion data. This method can be used either as a diagnostic tool or for experimental design. Frederik Bernd Laun1, Bram Stieltjes 1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Baden-Württemberg, Germany The multiple correlation function approach uses the eigensystem of the Laplace operator to compute the effect of diffusion weighting gradients much more efficiently than Monte-Carlo simulations. However the applicability is limited since the governing matrices could only be computed for few model systems. Here we present the solutions for a further model system, the equilateral triangle. One interesting finding is that the apparent diffusion coefficient for this confining geometry is not dependent on the gradient orientation for moderate b-values, while a clear orientation dependency is observed for high b-values. 1590. The Effect of Metric Selection on Averaging Diffusion Tensors When and Why Do Tensors Swell? Ofer Pasternak1, Nir Sochen2, Peter J. Basser3 1Brigham and Women's Hosptial, Harvard Medical School, Boston, MA, United States; 2Tel Aviv University, Israel; 3Section on Tissue Biophysics & Biomimetics (STBB), National Institutes of Health (NIH), Bethesda, MD, United States Metric selection is an essential step in performing diffusion tensor analysis, and here we investigate the selection effect on the estimation of FA, ADC and volume of mean tensors. We use Monte-Carlo simulations to generate noisy replicates, and compare estimations using a Euclidean and a Log-Euclidean metrics. The Log-Euclidean metric decreases tensor swelling, however, it is found to introduce other types of estimation biases. We find that for the case of thermal MR noise (rician), the swelling effect reduces estimation bias, and conclude that the Euclidean metric is an appropriate selection. 1591. An Improved Method for Diffusional Kurtosis Estimation Babak A. Ardekani1,2, Ali Tabesh, 1,3, Jens H. Jensen3, Joseph A. Helpern, 1,3, Alvin Bachman1, Howard Kushner4 1Center for Advanced Brain Imaging, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, United States; 2Department of Psychiatry, New York University School of Medicine, New York, United States; 3Department of Radiology, New York University School of Medicine, New York, NY, United States; 4Statistical Sciences and Research Division, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, United States In diffusional kurtosis imaging (DKI), the non-Gaussian nature of water diffusion in biological tissue is characterized by a kurtosis parameter, estimated in every voxel from a set of diffusion-weighted image acquisitions. This paper presents an improved method for estimating the kurtosis parameter in DKI. The specific contributions of this paper are twofold. (1) We propose a new method for imposing a positive-definiteness constraint on the fourth order tensor estimates and show its particular importance in DKI. (2) We propose using Mardias multivariate definition of kurtosis to characterize non-Gaussian diffusion, as opposed to mean univariate kurtosis used in previous publications. 1592. Supertoroid-Based Fusion of Cardiac Dt-Mri with Molecular and Physiological Information Choukri Mekkaoui1,2, Marcel Jackowski3, Roberto Martuzzi1, Albert Sinusas1 1Yale University School of Medicine, New Haven, CT, United States; 2Harvard Medical School, Boston, MA, United States; 3University of Sćo Paulo The supertoroid-based representation enhances the three-dimensional perception of biological tissue structure and organization using DT-MRI. The presence of two additional free parameters in the supertoroidal function allows the tuning of the glyph surface in order to highlight different structural properties. Alternatively, these parameters can be used to fuse the visualization of structure with complimentary information provided by other modalities. In this work, we combined DT-MRI, MMP-targeted 99mTc-labeled radiotracer (RP805) uptake, and 201Tl perfusion on a porcine heart at 2-weeks post-MI, showing that the supertoroidal model can fuse information arising from different modalities into a unique and comprehensive visualization scheme. Louisa Bokacheva1, Yousef Mazaheri1,2, Hedvig Hricak2, Jason Koutcher1 1Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, United States; 2Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, United States Diffusion-weighted (DW) MR images are contaminated with Rician noise, which leads to bias in ADC estimates. We explore accuracy and precision of calculating ADC from DW images acquired with multiple receiver channels using noise-corrected maximum likelihood estimation and uncorrected nonlinear least-squares fitting and log-linear fitting. Using Monte Carlo simulations, phantom and in vivo imaging of human prostate we demonstrate that accounting for Rician noise is important for images with variable SNR, for data acquired with phased arrays, and for achieving the maximum contrast between tissues with low and high ADC, which is often required for discriminating cancer and benign tissues on ADC maps. Diffusion-Based Segmentation Hall B Thursday 13:30-15:30 1594. Validation of a Thalamus Segmentation Based on Local Difusion Information Sarah Charlotte Mang1,2, Ania Busza, 2,3, Susanne Reiterer2, Wolfgang Grodd2, Uwe Klose2 1SIDT, German Cancer Research Center, Heidelberg, Germany; 2Section Experimental MR, Dept. of Neuroradiology, University Hospital Tuebingen, Tuebingen, Germany; 3MD/PhD Program, University of Massachusetts Medical School, Worcester, MA, United States Fast and accurate segmentation of thalamic nuclei is important for clinical applications. We validated a segmentation method that is based on the classification of the local diffusion direction. We could show the correspondence between our segmentation results and anatomy known from a stereotactic atlas by Morel et al. in a group study of 63 healthy subjects. To show the similarity of individual subject results we compared the center-of-mass coordinates of the individual clusters and could show that they correspond well to each other. 1595. Parcelation of the Human Premotor Cortex with DTI Technique Luca Nocetti1, Matteo Orlandi2, Davide Duzzi2, Patrizia Baraldi2, Carlo Adolfo Porro2 1Servizio Fisica Sanitaria, Az Osp.Univ. "Policlinico", Modena, Italy; 2Dipartimento di Scienze Biomediche, Universitą di Modena e Reggio Emilia The human premotor cortex is likely to include a mosaic of anatomically and functionally distinct areas, as in non-human primates, but its functional networks are only beginning to be understood. In this work we use the DTI technique to investigate the anatomical connectivity between the premotor cortex and the other part of the brain. Data were processed using probabilistic tractography (FDT tool included in FSL package) Single subject analysis was performed in different ways in order to check for repeatability. In particular we tested the eddy current correction step (ECC) as implemented in FSL package and different paths of coregistration. Multi-subjects analysis was performed in a fashion based on the results of the single-subject analysis. Through single-subject analysis an optimized processing procedure was defined. The multi-subject analysis revealed 4 main regions with different anatomical connectivity
yohan attal1, Charlotte Rosso2, Yves Samson2, Sylvain Baillet3 1CRICM - CNRS UMR7225, Paris, France, Metropolitan; 2AP-HP-Urgences Cérébro-Vasculaires, Paris, France, Metropolitan; 3MEG Program, Department of Neurology, Medical College of Wisconsin-Froedtert Hospital, Milwaukee, US We developed a fast and robust method to automatically segment ischemic lesions from a combination of acute diffusion-weighted MRI and apparent diffusion coefficient image volumes. This new segmentation technique extracts the ischemic areas from standard, clinical DWI image volumes of patient (N=40) with acute middle cerebral artery (MCA) stroke symptoms from the La Salpźtričre stroke center (Paris, France) database. 1597. TORTOISE: An Integrated Software Package for Processing of Diffusion MRI Data Carlo Pierpaoli1, Lindsay Walker1, Mustafa Okan Irfanoglu1, Alan Barnett1, Peter Basser1, Lin-Ching Chang1, Cheng Guan Koay1, Sinisia Pajevic1, Gustavo Rohde1, Joelle Sarlls1, Minjie Wu1 1NIH, Bethesda, MD, United States TORTOISE is an integrated and flexible software package for processing of DTI data, and in general for the correction of diffusion weighted images to be used for DTI and potentially for high angular resolution diffusion imaging (HARDI) analysis. It is non-commercial, and is freely available for download at www.tortoisedti.org. Timothy Lloyd Jones1, Ai Wern Chung2, B Anthony Bell1, Thomas Richard Barrick2 1Academic Neurosurgery Unit, St George's University of London, London, United Kingdom; 2Centre for Clinical Neurosciences, St George's University of London, London, United Kingdom Accurate delineation of brain tumour boundaries is crucial for diagnosis, surveillance and treatment planning (e.g. image guided cyto-reductive surgery or radiotherapy). We propose a novel whole brain k-medians diffusion tensor imaging (DTI) algorithm generating Diffusion Colour Maps (DCMs) incorporating T2 relaxation, isotropic (p) and anisotropic (q) characteristics. In this study, we have applied our technique to a variety of intracranial pathology revealing characteristic colour patterns for each lesion type and clearly delineated tumour boundaries, suggesting a potential role in diagnosis and treatment planning. Luke Bloy1, Ragini Verma2 1Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States Diffusion tensor imaging (DTI) has developed into an important tool for the study of WM diseases such as multiple sclerosis, as well as neurodevelopmental disorders, such as schizophrenia, epilepsy and autism. DTI is however limited in its ability to model complex white matter, which has prompted the development of higher order models(HOMs). Before HOMs can be used for group based statistical studies, algorithms for spatial normalization must be developed. We present a registration framework for images of fiber orientation distributions, a common HOM, which uses rotationally-invariant features of the FOD to drive a multi-channel diffeomorphic demons algorithm. 1600. A Multi-Resolution Watershed-Based Approach for the Segmentation of Diffusion Tensor Images Paulo Rodrigues1, Andrei Jalba2, Pierre Fillard3, Anna Vilanova1, Bart M. ter Haar Romeny1 1Biomedical Image Analysis, Eindhoven University of Technology, Eindhoven, Noord Brabant, Netherlands; 2Department of Computer Science, Eindhoven University of Technology, Eindhoven, Noord Brabant, Netherlands; 3CEA, Paris, France The investigation of Diffusion Tensor Imaging (DTI) data is of complex and exploratory nature: tensors, fiber tracts, bundles. This quickly leads to clutter problems in visualization as well as in analysis. We propose a new framework for the multi-resolution analysis of DTI. Based on fast and greedy watersheds operating on a multi-scale representation of a DTI image, a hierarchical depiction of such image is determined conveying a global-to-local view of the fibrous structure of the analysed tissue. We present a simple and interactive segmentation tool, where different bundles can be segmented at different resolutions. Diffusion Encoding Hall B Monday 14:00-16:00 1601. Optimization of Body-Centered-Cubic Encoding Scheme for Diffusion Spectrum Imaging Li-Wei Kuo1, Wen-Yang Chiang2, Fang-Cheng Yeh, 1,3, Van Jay Wedeen4, Wen-Yih Isaac Tseng1,5 1Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan; 2Center for Bioengineering and Bioinformatics, The Methodist Hospital Research Institute and Department of Radiology, The Methodist Hospital, Houston, TX, United States; 3Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States; 4MGH Martinos Center for Biomedical Imaging, Harvard Medical School, Charlestown, MA, United States; 5Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan The present study investigated the optimum parameters for body-centered-cubic sampling scheme as well as its accuracy of mapping complex fiber orientations compared with grid sampling scheme of diffusion spectrum imaging. A systematic angular analysis was performed on in-vivo data simulation and verification studies. Ours results showed that body-centered-cubic sampling scheme provided an incremental advantage in angular precision over the grid sampling scheme. Further, the capacity of half-sampling schemes based on the concept of q-space symmetry was also demonstrated. By considering the efficiency, this study showed that body-centered-cubic and half-sampling schemes may be potentially helpful for future clinical applications. Seongjin Choi1, Dustin Cunningham1, Francisco Aguila1, John Corrigan2, Jennifer Bogner2, Walter Mysiw2, Donald Chakeres1, Michael V. Knopp1, Petra Schmalbrock1 1Radiology, The Ohio State University, Columbus, OH, United States; 2Physical Therapy & Rehab, The Ohio State University As a part of optimization of diffusion tensor imaging (DTI) at 7T, we explored how voxel shape, voxel volume, and directional resolution affected FA measurement in normal aging brains at 7T and 3T. We observed statistically identical slopes while significantly different offset between the regression lines for FA along with age. In the study of SNR and FA over a range of reduction factors, we found that reduction factor affected standard deviation of measured FA values instead of FA itself. 1603. Optimal HARDI Acquisition Schemes for Multi-Tensor Models Benoit Scherrer1, Simon K. Warfield2 1Department of Radiology, Computational Radiology Laboratory , Boston, MA, United States; 2Department of Radiology, Computational Radiology Laboratory, Boston, MA, United States We show that multi-tensor models cannot be properly estimated with a single-shell HARDI acquisition because the fitting procedure admits a infinite number of solutions, melding the estimated tensors eigenvalues and the partial volume fractions. As a result, a uniform fiber bundle across its entire length may appear to grow and shrink as it passes through voxels and experiences different partial volume effects. Only the use of multiple-shell HARDI acquisitions allows the system of equations to be better determined. We provide numerical experiments to explore the optimal acquisition scheme for multi-tensor imaging. Ashish A. Tamhane1, Konstantinos Arfanakis1 1Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States The goal of this study was to investigate the effect of the number of blades, echo-train length (ETL), turbo-factor, and number of diffusion directions on the noise of fractional anisotropy (FA) in Turboprop diffusion tensor imaging (DTI). It was shown that the range of FA standard deviation (stdFA) values for different tensor orientations was lower when more diffusion directions were used. Additionally, stdFA decreased for an increasing number of blades, lower ETL, and lower turbo-factor. Hence, in Turboprop-DTI, optimal FA noise characteristics can be achieved by increasing the number of diffusion directions and blades, and decreasing the ETL and turbo-factor. Stefanie Schwenk1, Matthias Weigel1, Valerij G. Kiselev1, Juergen Hennig1 1Department of Diagnostic Radiology, University Hospital Freiburg, Medical Physics, Freiburg, Germany Diffusion weighted Hyperecho Imaging has maintained some interest during the last years since it has the potential to offer a probe for tissue microstructure. The present work studies the influence of idealized rectangular gradient shapes on the quantitation of effective b-factors in diffusion weighted Hyperecho preparation schemes for a variety of MR parameters. Julien Cohen-Adad1,2, Jennifer A. McNab1,2, Thomas Benner1,2, Maxime Descoteaux3, Azma Mareyam1, Van J. Wedeen1,2, Lawrence L. Wald1,2 1A. A. Martinos Center for Biomedical Imaging, Dept. of Radiology, MGH, Charlestown, MA, United States; 2Harvard Medical School, Boston, MA, United States; 3MOIVRE Centre, Department of Computer Science, Université de Sherbrooke, Sherbrooke, QC, Canada Head-insert gradients are particularly suitable for diffusion-weighted (DW) imaging due to a higher maximum strength, higher switching rate and higher duty cycle. In this paper we evaluate the performance of a head-insert combined with 32ch coil at 3T compared to conventional body gradients, for high spatial and angular resolution diffusion-weighted imaging. Bootstrap-based metrics demonstrate higher reproducibility of the Q-Ball estimate and lower uncertainty on the extracted maxima of the diffusion orientation distribution function. 1607. A Connectome-Based Comparison of Diffusion MR Acquisition Schemes Xavier Gigandet1, Tobias Kober2,3, Patric Hagmann1,4, Leila Cammoun1, Reto Meuli4, Jean-Philippe Thiran1, Gunnar Krueger2 1Signal Processing Laboratory (LTS5), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 2Advanced Clinical Imaging Technology, Siemens Schweiz AG-CIBM, Lausanne, Switzerland; 3Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 4Department of Radiology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland Diffusion MRI has evolved towards an important clinical and research tool. Though clinical routine is mainly using diffusion tensor imaging (DTI) approaches, q-ball imaging (QBI) and diffusion spectrum imaging (DSI) have become often used techniques in research oriented investigations. In this work, we aim at assessing the performance of various diffusion acquisition schemes by comparing the respective whole brain connection matrices. The results from the analysis indicate that (a) all diffusion scans produce a biologically meaningful mapping of the human connectome, and (b) more non-dominant fiber populations, e.g. neighboring association fibers in the 60-90 mm range, are better revealed with more complex diffusion schemes. Yohan van de Looij1,2, Nicolas Kunz1,2, Petra S. Hüppi1, Rolf Gruetter2,3, Stéphane V. Sizonenko1 1Division of Child Growth & Development, Department of Pediatrics, University of Geneva, Geneva, Switzerland; 2Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 3Department of Radiology, University of Geneva and Lausanne, Geneva and Lausanne, Switzerland A large number of small bore systems propose implemented sequences making easy the use of DTI but the choice of sequence parameters can have a huge impact on the derived tensor quantifications. The aim of this work was to study the influence of diffusion time (td) and brain microstructures on diffusion derived parameters in the rat brain at 9.4T. 3 repeated DTEPI images (4 shots) were performed with td = 10, 25 and 39 ms respectively. This study shows in white and gray matter a dependence of diffusion derived parameters on td from 10 ms to 25 ms. 1609. Using Statistical Resampling and Geometric Least Squares to Improve DTI Measures Efficiently Paul Andrew Taylor1, Bharat B. Biswal1 1Radiology, UMDNJ, Newark, NJ, United States An efficient method for improving DTI analysis is presented; geometric fitting and statistical resampling are used to calculate diffusion ellipsoids and associated quantities of interest with confidence intervals, and to greatly reduce the necessary number of gradient measures and therefore the scan time. Diffusion: Pulse Sequences Hall B Tuesday 13:30-15:30 1610. Isotropic High Resolution Diffusion-Tensor Imaging in Humans at 7T Robin Martin Heidemann1, Alfred Anwander1, Thomas Knoesche1, Thorsten Feiweier2, Fabrizio Fasano3, Josef Pfeuffer2, Robert Turner1 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2Siemens Healthcare Sector, Erlangen, Germany; 3Fondazione Santa Lucia, Rome, Italy For isotropic high resolution DTI at ultra-high field strength, susceptibility effects and T2* decay must be properly addressed. A combination of reduced FOV imaging (zoomed imaging) and parallel imaging is optimized here, achieving high acceleration factors. This approach enables DWI acquisitions with 1 mm isotropic resolution at 7T. The high quality of the DTI data provides a high level of anatomical details. Samantha J. Holdsworth1, Stefan Skare1, Rafael Luis O'Hallaran1, Roland Bammer1 1Radiology, Stanford University, Palo Alto, CA, United States Diffusion-weighted imaging (DWI) using EPI has been limited by geometric distortion and blurring, particularly in regions with large off-resonance effects. Distortions can be reduced by reducing the phase-encode FOV, and by reducing the echo-spacing. For the former, we implement the ZOnal Oblique Multislice (ZOOM) technique, which uses a tilted refocusing pulse to spatially select a region of interest. To reduce echo-spacing further, we use the readout-segmented (RS)-EPI technique. We show that the combination of the ZOOM pulse and RS-EPI results in images of the spine and orbits with reduced geometric distortion. 1612. Robust Fat Suppression for High-Resolution Diffusion-Weighted Imaging Joelle E. Sarlls1,2, Wen-Ming Luh3, Carlo Pierpaoli1 1NICHD, National Institutes of Health, Bethesda, MD, United States; 2Henry M. Jackson Foundation, Rockville, MD, United States; 3NIMH, National Institutes of Health, Bethesda, MD, United States Although spectral-spatial excitation pulses provide single-shot EPI diffusion-weighted images without signal from fat, they are limited in the attainable minimum slice thickness. To achieve higher resolution, traditional fat supression methods must be used. In this work, an exhaustive investigation was performed to determine which, if any, implementation of the slice-selective gradient reversal method completely supressed the fat signal. The dual-spin-echo diffusion preparation implementation, with opposite polarity slice-select gradients for the two 180° refocusing pulses, combined with traditional fat supression was found to completely suppress fat in phantoms and in vivo. Murat Aksoy1, Christoph Forman1, Matus Straka1, Samantha Jane Holdsworth1, Stefan Tor Skare1, Juan Manuel Santos2, Joachim Hornegger3, Roland Bammer1 1Department of Radiology, Stanford University, Stanford, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States; 3Computer Science, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany Due to the prolonged acquisition time, correction of rigid-head motion artifacts is essential for diagnostic image quality in diffusion tensor imaging (DTI). In this study, we performed prospective, real-time rigid head motion correction for DTI. This is achieved by using a single camera mounted on a head coil together with a 3D, self-encoded checkerboard marker that is attached to the patient's forehead. The results show that the proposed setup is very effective in removing rigid head motion artifacts even for very motion-sensitive scans, such as DTI. Yu-Chien Wu1, Charles A. Mistretta2, Andrew L. Alexander3, Trevor Andrews4, Paul J. Whalen5, James V. Haxby5 1Dartmouth Brain Imaging Center, Dartmouth College, Hanover, NH, United States; 2Wisconsin Institutes for Medical Research, University of Wisconsin-Madison, Madison, WI, United States; 3Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 4College of Medicine, University of Vermont, Burlington, VT, United States; 5Psychological & Brain Sciences, Dartmouth College, Hanover, NH, United States High angular resolution diffusion imaging (HARDI) has drawn considerable attention for its powerful directional measure on predicting fiber orientation at the level of subvoxel dimension. HARDI may improve the accuracy of WM tractography, which leads to an important application of brain structural connectivity. However, due to the higher diffusion weighting (DW) b-value and substantial number of DW directions, its long scan time is often the obstacle for extensive clinical application. In this study, we investigate the feasibility of the new reconstruction method, highly constrained back projection reconstruction, which may significantly reduce HARDI scan time.
1615. 3D PROPELLER-Based Diffusion Weighted Imaging with Improved Robustness to Motion Eric Aboussouan1, Jim Pipe1 1Barrow Neurological Institute, Phoenix, AZ, United States The previously described ROTOR (Radially Oriented Tri-Dimensionally Organized Readouts) pulse sequence allows 3D DWI with high SNR efficiency and lower SAR compared to DW FSE and reduced off-resonance artifacts and improved 3D phase correction compared to DW EPI. This work describes improvements in the pulse sequence and reconstruction scheme allowing greater robustness to motion. Blades are made wider by combining odd and even non-CPMG echoes and are gridded off-center to effectively reflect the linear component of the motion phase. 1616. Multi-Shot SENSE DWI at 7T Ha-Kyu Jeong1,2, Adam W. Anderson1,2, John C. Gore1,2 1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States; 2Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States We developed a simple reconstruction method for multi-shot SENSE diffusion weighted data using an interleaved EPI sequence. The reconstruction was done independently for each column of the image by combining image unwrapping and phase corrections. To estimate shot-to-shot phase variations due to subject motion during diffusion encoding, a 2-D navigator-echo acquisition was used following the image-echo acquisition. Both of the echo acquisitions were SENSE accelerated reducing scan duration, susceptibility and T2* effects. Our reconstruction method and pulse sequence produced diffusion weighted images free of ghost artifacts at 7 Tesla. 1617. Whole-Blade PROPELLER DWI Chu-Yu Lee1, Zhiqiang Li2, Eric Aboussouan1, Josef P. Debbins, 1,3, James G. Pipe3 1Electrical Engineering, Arizona State University, Tempe, AZ, United States; 2GE Healthcare, Waukesha, WI, United States; 3Keller Center for Imaging Innovation, Barrow Neurological Institute, Phoenix PROPELLER [1] is a variant of multi-shot FSE technique, providing a high-resolution DWI with excellent immunity to off-resonance. Its self-navigated nature around the center of K-space also allows for motion correction. The odd/even echo phase inconsistencies in the non-CPMG echo train were addressed using the ”§split-blade”Ø method [2], where the blade width was reduced by a factor of two, making the motion-related phase more difficult to remove [3]. Thus, this work applied the ”§whole blade”Ø method [3] to create wider blades for robustly removing the motion-induced phase. The proposed scheme added the reference blade (only for b=0) to effectively remove the coil phase of odd/even echoes. This reference blade can also be used for GRAPPA kernel training for parallel imaging to further widen the blade width and reduce the scan time. 1618. High Resolution 3D Multi-Slab Multi-Shot Spin Echo Diffusion-Weighted Imaging Anh Tu Van1, Dimitrios C. Karampinos2, Bradley P. Sutton3,4 1Electrical and Computer Engineering, University of Illinois, Urbana, IL, United States; 2Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States; 3Bioengineering, University of Illinois, Urbana, IL, United States; 4Beckman Institute, University of Illinois, Urbana, IL, United States High isotropic resolution diffusion-weighted imaging is required in order to reduce partial volume effects in the estimation of diffusion metrics. In the present work, a novel high resolution 3D spin echo diffusion-weighted acquisition strategy is proposed. The acquisition is time efficient, fairly immune to gross motion and pulsation effects, and has a simple diffusion-weighted signal model. High quality, high resolution (1.88 x 1.88 x 1.88 mm3) diffusion-weighted images, FA maps, color-coded FA maps (13 directions) with whole brain coverage were achieved within a reasonable scan time. Mathias Engström1,2, Anders Nordell1,2, Magnus Mårtensson1,2, Bo Nordell1, Roland Bammer3, Stefan Skare, 2,3 1Department of Medical Physics, Karolinska University Hospital, Stockholm, Sweden; 2Karolinska MR Research Center, Karolinska Institute, Stockholm, Sweden; 3Radiology, Stanford University, Stanford, CA, United States A new readout strategy for 3D-DWI is proposed using EPI and multi-slab encoding, with the purpose of achieve sharp and thin slice profiles. 1620. Improved 3-Dimensional Reconstruction of Diffusion Data Using Overlapping Slices Rita G. Nunes1, Joseph V. Hajnal1 1Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, London, United Kingdom As Diffusion-Weighted images are inherently very sensitive to motion, full brain coverage is achieved by imaging multiple 2D single shot slices. However, as most fiber tracts in the brain have a 3-dimensional structure, ensuring that the anatomy is fully sampled along all three dimensions is likely to be important. Conventionally, the same slice prescription is used for all diffusion sensitization directions. We demonstrate that by using overlapping slices and/or combining slices acquired along orthogonal directions higher fidelity anisotropy maps can be reconstructed. Using this type of geometry should also increase data robustness in the presence of more severe subject motion. 1621. Diffusion Weighted Turbo-STEAM ZOOM Imaging of the Lumbar Spine Patrick Hiepe1, Karl-Heinz Herrmann2, Christian Ros2, Jürgen R. Reichenbach2 1Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital , Jena, Germany; 2Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital, Jena, Germany So far, most clinical DWI applications have relied on EPI although DWI EPI is limited by susceptibility artifacts. STEAM MRI with robust turbo-FLASH readout is a fast imaging technique with subsecond measurement times. This robustness is traded against SNR by using a less signal efficient acquisition technique. To achieve maximum efficiency of the turbo-STEAM sequences a reduced number of PE lines is necessary. An effective way is to utilize the ZOOM imaging technique, which limits the excited FOV in the PE direction to include only the ROI. This can be used to measure various regions of the body with a narrow FOV, e.g. lumbar spine, without the occurrence of foldover or aliasing artifacts. In comparison with EPI, DW ZOOM single-shot STEAM MRI of the lumbar spine exhibits a reduced SNR, but avoids regional signal losses and geometric distortions. Furthermore, no fat suppression is necessary. Our case report indicates that the DW ZOOM turbo-STEAM MRI technique appears to be a good alternative to the standard DW EPI. 1622. Parallel Line Scan Diffusion Tensor Imaging Renxin Chu1, Bruno Madore1, Lawrence P. Panych1, Stephan E. Marier1 1Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States Diffusion tensor imaging (DTI) has been widely used in the study of white matter-related diseases. Single-shot echo-planar imaging (EPI) is usually the preferred technique, but EPI images may exhibit severe geometric distortions, especially near the skull base. Line scan diffusion imaging (LSDI) is a one-dimensional Fourier encoding technique with considerable robustness against motion and geometric distortions. We present a parallel LSDI diffusion tensor imaging technique with acceleration along two dimensions, with 3D whole brain coverage and four-fold acceleration. The speed-up remarkably comes at no cost in SNR, and preserves the LSDI immunity to susceptibility-induced signal losses and geometric image distortions. Sudhir Ramanna1, Vibhas Deshpande2, David Feinberg1,3 1Advanced MRI Technologies, Sebastopol, CA, United States; 2Siemens, United States; 3University of California, Berkeley, San Francisco, CA, United States The use of high b-values encoded with lengthy high amplitude gradient pulses place limitations on diffusion imaging with HARDI techniques. In this work, we develop and evaluate SIR with two and three echoes per read period (SIR-2, SIR-3) for HARDI imaging. Both SIR-2 and SIR-3 EPI sequences are shown to be useful for simply reducing scan time, for obtaining higher resolution or field of view on the slice axis with more slices per TR or instead controlling the heat limitations using high b-values by reducing the gradient duty cycle in HARDI acquisitions. Diffusion: Distortion Correction, QA & Miscellaneous Hall B Wednesday 13:30-15:30 Rita G. Nunes1, Ivana Drobnjak2, Stuart Clare3, Peter Jezzard3, Mark Jenkinson3 1Robert Steiner MRI Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, London, United Kingdom; 2Centre for Medical Image Computing, University College London, London, United Kingdom; 3Oxford Centre for Functional Magnetic Resonance Imaging of the Brain, University of Oxford, Oxford, United Kingdom Echo-planar diffusion-weighted images can display significant geometric distortions due to eddy current fields. Several diffusion preparation schemes have been proposed, which can null eddy currents with a single time constant. We use an MRI simulator to compare the performance of three such sequences in the presence of multiple components, and investigate whether affine registration is capable of correcting for the resulting distortions. Our study confirms that, in general, doubly-refocused sequences perform better than single spin-echo approaches, and suggest that when the use of two refocusing pulses is not desirable, it may be preferable to use a modified single spin-echo sequence. 1625. Homodyne Reconstruction of Partial Fourier Readout-Segmented EPI for Diffusion Imaging Robert Frost1, David Andrew Porter2, Thorsten Feiweier2, Peter Jezzard1 1FMRIB Centre, University of Oxford, Oxford, United Kingdom; 2Siemens Medical Solutions, MR Applications Development, Erlangen, Germany This study demonstrates that homodyne partial Fourier reconstruction can be used to reduce acquisition time in readout-segmented EPI with GRAPPA parallel imaging without significantly compromising image quality. Diffusion images and signal-to-noise ratio comparisons of full k-space and partial Fourier images are presented. By acquiring 6/11 readout segments, a 40% reduction in scan time could be achieved which would allow high-resolution tractography in clinically realistic time frames. Se-Hong Oh1, Jun-Young Chung1, Sung-Yeon Park1, Daeshik Kim2, Myung-Ho In3, Maxim Zaitsev4, Oliver Speck3, Young-Bo Kim1, Zang-Hee Cho1 1Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea, Republic of; 2Department of Electrical Engineering, Korea Advance Institute of Science and Technology, Daejeon, Korea, Republic of; 3Department of Biomedical Magnetic Resonance, Institute for Experimental Physics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany; 4Department of Radiologic Research, Medical Physics, University Hospital of Freiburg, Freiburg, Germany To acquire high resolution DTI images at 7T, we should solve two major problems (One thing is reduce TE, another thing is correct geometric distortion). To minimize TE and increase SNR, we modified EPI based double echo diffusion sequence to EPI based single echo diffusion sequence. Afterwards we could reduce 16ms. To correct geometric distortion use distortion and non-distortion dimensional combined PSF correction method. Then we can correct the geometric distortion both compressed and stretched area more accurately. 1627. A Novel Robust Algorithm to Correct for Eddy Current Distortions in High B-Value Diffusion MRI Henrik Hansson1, Jimmy Lätt, 12, Freddy Ståhlberg1,3, Markus Nilsson1 1Department of Medical Radiation Physics, Lund University, Lund, Sweden; 2Center for Medical Imaging and Physiology, Lund University Hospital, Lund, Sweden; 3Department of Diagnostic Radiology, Lund University, Lund, Sweden Eddy currents distort diffusion-weighted images, which give rise to artefacts in the estimated apparent diffusion coefficient and the diffusion kurtosis. Current correction methods are not effective for b-values greater than 1000 s/mm2. We have developed a correction algorithm based on comparison of all images in an image set, instead of separate volumes. This allows model based distortion correction by maximizing the local correlation of the entire image set. 1628. Rapid Automated QA for Diffusion MRI Adriaan L. Moerland1, Elizabeth A. Moore2 1Advanced Development, Philips Healthcare BV, Best, Netherlands; 2MR Clinical Science, Philips Healthcare BV, Best, Netherlands Diffusion MRI is increasingly important in clinical radiology, however the technique is very sensitive to system defects in the gradient chain. A new method has been developed for easy QA in diffusion MRI. The acquisition is 3 fast DTI scans on a spherical aqueous phantom, taking less than 3 minutes. Analysis is fully automated and derives measures of deformation of the circular phantom image as well as apparent diffusion coefficient ADC and fractional anisotropy FA values. Two of the deformation measures were found to be highly sensitive to gradient defects such as eddy current (mis)calibration. Patrick William Hales1, Rebecca Burton2, Christian Bollensdorff2, Jurgen E. Schneider1 1Cardiovascular Medicine, Oxford University, Oxford, Oxon, United Kingdom; 2Physiology, Anatomy & Genetics, Oxford University, Oxford, Oxon, United Kingdom The influence of both SNR and diffusion gradient sampling scheme on the precision and accuracy of high resolution (203 μm) DTI data acquired in the ex vivo rat heart has been investigated. We demonstrate how the use of reduced encoding of diffusion weighted images using the approximate generalized series reconstruction technique can increase SNR without increasing scan time, and how this can be employed to reduce the overall error in the primary eigenvector orientation. Julien Valette1,2, Denis Le Bihan2, Franck Lethimonnier2 1CEA-MIRCen, Fontenay-aux-Roses, France; 2CEA-NeuroSpin, Gif-sur-Yvette, France It has been recognized in the past that the non-linear phase induced by frequency-swept pulses may cause diffusion-weighting. In the present work, the origins of the non-linear phase dispersion induced by frequency-swept pulses are revisited, in order to assess whether the phase variation of the B1 field during the sweep should be explicitly considered when calculating diffusion weighting. Following this analysis, an analytical expression is derived for diffusion-weighting induced by a pair of slice selective hyperbolic secant pulses, and confronted to numerical simulation of the Bloch equations including diffusion. 1631. On the Accuracy of Diffusion Models for Fast Low-Angle Short-TR SSFP-Echo (FLASH-DW SSFP) Oliver Bieri1, Carl Ganter2, Klaus Scheffler1 1Radiological Physics, University of Basel Hospital, Basel, Switzerland; 2Department of Diagnostic Radiology, Technical University Munich, Munich, Germany Several models have been developed for the description of diffusion in steady-state free precession (SSFP) sequences. For clinical practice, high SNR and short acquisition times are desirable with DW-SSFP. In this work, a new approach for quantitative diffusion imaging is proposed using a fast low-angle short-TR (FLASH) diffusion-weighted (DW) SSFP sequence. The accuracy of diffusion models is assed in-vitro and the feasibility of high resolution quantitative diffusion mapping is demonstrated in-vivo for human articular cartilage. Jun-Cheng Weng1 1Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan Fundamental relationships between diffusion tensor imaging (DTI) and q-space imaging can be derived which establish conditions when these two complementary MR methods are equivalent. When the 3D displacement distribution is measured by q-space imaging with large displacement and small q vector, the result is similar to 3D Gaussian assumed in DTI. Combing displacement information from q-space imaging and fiber direction from DTI, distribution of axonal diameters and directions could be derived at the same time. The study proposed a novel technique, q-space diffusion tensor imaging (qDTI), combined with two image reconstruction methods based on the assumption to simultaneously map axonal diameter distribution and direction of rat brain. One was tensor-based method. The 3D Gaussian displacement distribution could be obtained directly by the displacement tensor. The other was displacement projection method. The effective axonal diameter was defined as the average of several displacements projected to the direction of the fiber section. They provided MR images in which physical parameters of water diffusion such as the mean displacement and maximum diffusivity of water molecules were used as image contrast. Our results demonstrated that two qDTI methods both produced reasonable distribution of effective axonal diameters and directions in rat brain. 1633. Measuring Isotropic Diffusion with Rotating Diffusion Gradients Irvin Teh1,2, Xavier Golay1,3, David Larkman2 1Lab of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore; 2Imaging Sciences Department, Imperial College London, London, United Kingdom; 3Institute of Neurology, University College London, London, United Kingdom A diffusion-weighted fast spin echo periodically rotated overlapping parallel lines with enhanced reconstruction (DW-FSE-PROPELLER) sequence was combined with a multiple axis Stejskal-Tanner diffusion weighting scheme that rotated and alternated across blades. This reduced the number of DW acquisitions needed to acquire the mean apparent diffusion coefficient from three to one, halving the total acquisition time. This motion and distortion robust method was tested in the in-vivo mouse brain and compared to previously proposed rotating DW strategies. Noam Shemesh1, Evren Özarslan2, Peter J. Basser2, Yoram Cohen1 1School of Chemistry, Tel Aviv University, Tel Aviv, Israel; 2Section on Tissue Biophysics and Biomimetics, NICHD, National Institutes of Health, Bethesda, MD, United States Diffusion-diffraction minima, which convey important microstructural information, vanish from the signal decay in single-pulsed-field-gradient (s-PFG) experiments conducted on specimens characterized by size distributions. The double-PFG (d-PFG) methodology, an extension of s-PFG, was recently predicted to exhibit zero-crossings (analogous to s-PFG diffusion-diffraction minima) that would persist even when the specimen is characterized by a broad size-distribution. We therefore studied the signal decay in both s- and d-PFG in size-distribution phantoms consisting of water-filled microcapillaries of various sizes. We find that the diffusion-diffraction minima in s-PFG indeed vanish, while the zero-crossings in d-PFG indeed persist, allowing to extract important microstructural information. Christine Marie Zwart1, David H. Frakes1,2, Josef P. Debbins3 1School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, United States; 2School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, AZ, United States; 3Keller Center for Imaging Innovation, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States Many diseases of the white matter are accompanied by an observable decrease in fractional anisotropy as measured with Diffusion Tensor Imaging. This decrease can be attributable to a general increase in extracellular space or an absence of collinearity with respect to axon orientations. For studying the progression of diseases such as multiple sclerosis (demyelination) and epilepsy (disorder) we have developed a correlation based metric that distinguishes between these processes. Diffusion Artifacts & Reproducibility Hall B Thursday 13:30-15:30 1636. Enhanced ICBM Diffusion Tensor Template of the Human Brain Shengwei Zhang1, Huiling Peng1, Robert Dawe1, Konstantinos Arfanakis1 1Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States The purpose of this study was to develop a diffusion tensor (DT) template that is more representative of the microstructure of the human brain, and more accurately matches ICBM space than existing templates. This was achieved by normalizing 67 DT datasets with minimal artifacts using high-dimensional non-linear registration. The normalization accuracy achieved for the 67 datasets was evaluated. The properties of the resulting template were compared to those of the current state of the art. The new template was shown to be more representative of single-subject human brain diffusion characteristics, and more accurately matches ICBM space than previously published templates. Shengwei Zhang1, John D. Carew2, Konstantinos Arfanakis1 1Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States; 2Dickson Institute for Health Studies, Carolinas Healthcare System, Charlotte, NC, United States Development of a diffusion tensor (DT) brain template that is not biased by the properties of a single subject requires averaging of the DT information from multiple subjects. The purpose of this study was to investigate the variability of DT characteristics in templates developed using different numbers of subjects. The variability of template DT properties decreased as the number of subjects increased. Furthermore, DT templates constructed from 30 subjects demonstrated high stability in tensor properties of voxels with FA=(0.6,1]. When considering voxels with FA=(0.2-1], more than 60 subjects were necessary in order to achieve sufficiently high stability in tensor properties. Anton Orlichenko1, Robert J. Dawe2, Huiling Peng2, Konstantinos Arfanakis2 1Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, IL, United States; 2Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States Use of diffusion tensor imaging (DTI) data with minimal image artifacts may enhance the accuracy of inter-subject spatial normalization. This effect was investigated by comparing the coherence of primary eigenvectors after normalizing separately a) data with minimal artifacts, and b) data with typical field inhomogeneity-related artifacts, acquired on the same subjects. Tensors derived from data with minimal artifacts were found to have higher primary eigenvector coherence in white matter, compared to tensors derived from data contaminated with image artifacts. These results demonstrate that achieving the most accurate spatial normalization of DTI data requires minimization of image artifacts. 1639. The Effect of Template Selection on Diffusion Tensor Imaging Voxel Based Analysis Results Wim Van Hecke1,2, Caroline Sage2, Jan Sijbers3, Stefan Sunaert2, Paul M. Parizel1 1Department of Radiology, Antwerp University Hospital, Antwerp, Belgium; 2Department of Radiology, Leuven University Hospital, Leuven, Belgium; 3VisionLab, University of Antwerp, Antwerp, Belgium In this work, we examined the effect of the template or atlas selection on the voxel based analysis results of diffusion tensor images. To this end, simulated data sets were used. 1640. Artificial Phantoms for Studies of Anisotropic Diffusion in the Brain Ezequiel Alejandro Farrher1, Erasmo Batta1, Yuliya Kupriyanova1, Oleg Posnansky1, Farida Grinberg1, N Jon Shah1,2 1Medical Imaging Physics, Institute of Neuroscience and Medicine 4 , Forschungszentrum Juelich GmbH, Juelich, Germany; 2Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany Diffusion Tensor Imaging (DTI) provides access to fibre pathways and structural integrity in the white matter and finds important applications in the clinical practice. Many advanced techniques have been recently suggested for the reconstruction of the diffusion orientation distribution function with an enhanced angular resolution (HARDI). Examination of the sensitivity of the proposed diffusion indices to the underlying microstructure requires a development of the model systems with deliberately tailored properties. The aim of this work was to construct artificial phantoms that are characteristic of sufficiently strong diffusion anisotropy and are suitable for the validation of the analytical models. 1641. Evaluating the Uncertainty of DTI Parameters at 1.5, 3.0 and 7.0 Tesla Daniel Louis Polders1, Alexander Leemans2, Johannes M. Hoogduin1,3, Jeroen Hendrikse1, Manus Donahue4, Peter R. Luijten1 1Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 3Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Netherlands; 4Department of Clinical Neurology, University of Oxford, Oxford, United Kingdom Diffusion Tensor Imaging data acquired at increased field strength shows increased Signal to Noise Ratio. This work compares the uncertainties of DTI-based metrics when scanning at 1.5 3 and 7T. By scanning the same nine volunteers at each field strength, and applying a wild bootstrap method to calculate the uncertainty of the fitted tensors, it is shown that with increasing SNR, the uncertainties for FA and the primary eigenvector decrease. 1642. Validation of Diffusion Tensor Imaging in the Presence of Metal Implants Felix Schwab1, Bram Stieltjes2, Frederik Bernd Laun3 1Medical Physics in Radiology, Deutsches Krebsforschungszentrum , Heidelberg, Baden Württemberg, Germany; 2Radiology, Deutsches Krebsforschungszentrum, Heidelberg, Germany; 3Medical Physics in Radiology, Deutsches Krebsforschungszentrum, Heidelberg, Baden Württemberg, Germany The diffusion weighted imaging of the spinal chord is often impeded by metal implants. A quantitative analysis of these effects is performed on a standard titanium implant using phase maps acquired from FLASH sequences and ADC maps acquired from diffusion weighted EPI sequences. The shift δb/b is calculated as a measure of the error. Artefacts caused by the separate parts of the implant are mostly benign and thus diffusion measurements should be feasible if a small distance to the implant is observed. Nico Dario Papinutto1, Jorge Jovicich1 1Center for Mind/Brain Sciences, University of Trento, Mattarello, Trento, Italy The accuracy and precision of a Diffusion tensor imaging (DTI) acquisition of in-vivo human brains depends on both the acquisition protocol and post-processing used for data analysis. In many cases multiple acquisitions from the same session are averaged to increase signal-to-noise ratio and reduce sensitivity to motion during the acquisition. The complexity of DTI datasets allows for several processing paths to complete eddy current correction, co-registration, averaging and tensor fitting. Here we assess the sensitivity of fractional anisotropy (FA) test-retest reproducibility to different methods for merging multiple within-subject DTI acquisitions. Derek K. Jones1 1CUBRIC, Cardiff University , Cardiff, Wales, United Kingdom Eddy currents plague diffusion MRI. When they produce a stretch / compression of the image along the phase encode direction, the resultant change in voxel volume leads to a reduction/ increase in signal intensity. Many eddy current correction packages fail to account for this signal change. Here we show that the consequences can be drastic for diffusion tensor MRI, with biases in fibre orientation being as big as 5 degrees in regions of low anisotropy. We conclude that the signal intensity must be modulated by the volumetric change, in order to obtain meaningful and robust results from diffusion MRI. Lingchih Lin1, Xiaoxu Liu2, Jianhui Zhong3 1Department of Physics and Astronomy , University of Rochester, Rochester, NY, United States; 2Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY, United States; 3Department of Imaging Sciences, University of Rochester, Rochester, NY, United States The analytical relationships of diffusion tensor (DT) derived parameters were compared to quantify the subtle dependent variation between these metrics. This sensitivity evaluation includes the estimation from Monte Carlo simulations and the implementation in a study of five healthy controls and five patients of secondary progressive multiple sclerosis (SPMS). The fractional anisotropy (FA) was simulated as one-dimensional, two-dimensional, and three-dimensional function and reveal distinct properties in different tissue categories. Both white matter (WM) and gray matter (GM) deterioration were observed with decreasing and increasing FA and changes in radial and axial diffusivities in SPMS. 1646. DTI in the Clinic: Evaluating the Effects of Smoothing Marta Moraschi1, Gisela E. Hagberg2, Giovanni Giulietti1, Margherita Di Paola2, Gianfranco Spalletta2, Bruno Maraviglia3, Federico Giove3 1MARBILAb, Enrico Fermi Center, Rome, Italy; 2Santa Lucia Foundation, Rome, Italy; 3Department of Physics, 'Sapienza' University of Rome, Rome, Italy We evaluated the effects of smoothing on the outcomes of a Diffusion Tensor Imaging (DTI) voxel-based analyses trying to separate differential effects between patients and controls. Gaussian smoothing introduced a high variability of results in clinical analysis, greatly dependent on the kernel size. On the contrary, anisotropic smoothing proved itself capable of maintaining boundary structures, with only moderate dependence of results on smoothing parameters. Our study suggests that anisotropic smoothing is more suitable in voxel based DTI studies; however, regardless of technique, a moderate level of smoothing seems to be preferable considering the artifacts introduced by this manipulation. 1647. CSF Contamination Correction in DTI Tractography of the Fornix in Elderly Subjects Sinchai Tsao1, Darryl H. Hwang1, Manbir Singh, 12 1Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States; 2Department of Radiology, University of Southern California, Los Angeles, CA, United States The microstructural integrity of the limbic regions is frequently compromised in neurodegenerative diseases such as Alzheimer Disease (AD). A key limbic region is the fornix located proximal to the ventricles. Given the relatively large voxel size used in most clinical DTI acquisitions, the probability of CSF contamination in the fornix is high, often leading to interruption of tracts due to either a reduction in FA or misdirection due to erroneous eigenvector estimation, particularly in AD where ventricles are enlarged. FLAIR DTI has been used by many investigators to suppress CSF (e.g. [1,2,3,4]) but at the expense of SNR and data acquisition time and to our knowledge, FLAIR DTI is rarely used in clinical studies. Aiming toward eventual quantification of DTI metrics such as FA and tract density in the fornix and other limbic pathways in AD, the objective of this work was to develop a post-processing strategy to correct partial volume effects such that it could be used to analyze existing clinical DTI data. 1648. SPM Normalisation Toolbox for Diffusion Weighted Images Volkmar H. Glauche1, Siawoosh Mohammadi2, Michael Deppe2 1Department of Neurology, University Hospital Freiburg, Freiburg, Germany; 2Department of Neurology, University of Muenster, Germany The toolbox implements normalisation strategies to prepare data for VBM-style voxel-based statistics of FA images (FA-VBS) in SPM. It provides a convenient interface to spatially normalise DWI datasets even if no additional anatomical images are available. It integrates tightly into the SPM8 batch system within the Diffusion Toolbox. The resulting normalised images can be used for voxelwise or multivariate analyses in any of the common analysis packages for VBM. This toolbox may therefore help to standardize the FA-VBS normalisation step. 1649. Cerebrospinal Fluid as an Internal Quality Control Marker Ryan J. Bosca1,2, A.J. Kumar1, Jihong Wang1 1The University of Texas M.D. Anderson Cancer Center, Houston, TX, United States; 2The University of Texas Graduate School of Biomedical Sciences, Houston, TX, United States Cerebrospinal fluid (CSF) is a good candidate for an internal quality control marker of diffusion tensor imaging because the diffusion properties should be close to known values and show little variation over time. The apparent diffusion coefficient (ADC) and fractional anisotropy (FA) for 174 DTI (111 at 1.5T, 63 at 3.0T) studies for 20 patients were measured. Coefficients of variation were calculated for all studies at 1.5T (4.2%, 14.2%) and 3.0T (6.2%, 19.7%) for ADC and FA values, respectively. Small variations in the ADC were observed indicating CSF as a promising candidate for an internal quality control marker. Kurt Hermann Bockhorst1, Cheukkai K. Hui1, Ponnada A. Narayana1 1DII, University of Texas, Houston, TX, United States We created a batch process which refines raw DTI data; it reduces ghosts and filters noise, strips extramenigeal tissue and registered to an atlas, which we created from high resolution DTI data to avoid mis-registration with spin-echo derived data. 3D-masks of 17 brain structures were created to facilitate automatic evaluation of the data. 1651. Repeatability of Mono- And Bi-Exponentially Modelled Diffusion at 3 Tesla Peter Gibbs1, Martin D. Pickles1, Lindsay W. Turnbull1 1Centre for MR Investigations, University of Hull, Hull, East Yorkshire, United Kingdom Recent work has demonstrated that it is technically possible to acquire DWI data with low b-values to quantify the perfusive fraction of the ADC decay curve via bi-exponential modelling. This work seeks to assess the repeatability of such modelling and the dependence on accurate b-value implementation by system manufacturers. A repeatability of 21% for mono-exponential fitting indicates its efficacy for monitoring treatment induced changes. Bi-exponential fitting is found to be less repeatable, especially the perfusive fraction parameter. Diffusion at 7T Hall B Monday 14:00-16:00 Ralf Luetzkendorf1, Oliver Speck2, John Grinstead3, Joerg Stadler4, Johannes Bernarding1 1Department for Biometry and Medical Informatics, OvG University Magdeburg, Magdeburg, Saxony Anhalt, Germany; 2Biomedical Magnetic Resonance, OvG University Magdeburg, Magdeburg, Germany; 3Siemens Medical Solutions USA, Inc; 4Leibniz Institute for Neurobiology High resolution DTI at ultra-high fields is advantageous as the initially higher signal-to-noise ratio allows to increase the resolution while simultaneously counteracting the according signal losses. Stronger gradients will also enable to apply larger diffusion-weighting at still acceptable TE times. We aimed to reduce TE to overcome the disadvantages of ultra high field conditions such as increased distortions and shortened T2 values. To this purpose we used a new 70 mT/m whole body gradient system for a 7T MR scanner and an improved DTI sequence with a single refocusing pulse to acquire isotropic DTI images with a resolution of (1.4 mm) 3. Hermien E. Kan1, Matthias J.P. van Osch1, Maarten J. Versluis1, Aranee Techawiboonwong2, Dinesh K. Deelchand3, Pierre G. Henry3, M Marjanska3, Mark A. van Buchem1, Andrew G. Webb1, Itamar Ronen, 12 1C.J. Gorter Center, department of radiology, Leiden University Medical Center, Leiden, Netherlands; 2Radiology, Boston University, Boston, United States; 3Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, Minneapolis, MN, United States Assessment of diffusive properties of metabolites using diffusion weighted spectroscopy has so far been, in humans, limited to the brain metabolites N-acetyl aspartate, creatine and phosphocreatine and choline. To further assess substructural differences, it would be advantageous to also study ADCs of other metabolites, like myo-inositol, glutamate and glutamine. In this study, we obtained ADC values of these metabolites in human grey and white matter, and observed that in grey matter overall ADCs were lower compared to white matter with a significantly reduced glutamate. This is in agreement with observations in monkeys, and indicates increased diffusion restriction in grey matter. Emily Turner Wood1,2, Daniel S. Reich2,3, Jonathan A. Farrell3,4, Joseph S. Gillen4, Peter B. Barker3, Itamar Ronen5 1Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2NeuroImmunology Branch (NINDS), National Institutes of Health, Bethesda, MD, United States; 3Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 4F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States; 5Leiden University Medical Center, Leiden, Netherlands Diffusion tensor spectroscopy (DTS) combines features of DTI and spectroscopy to provide information about the diffusion of intracellular metabolites and therefore specific information about tissue microstructure and health. We compare the diffusion properties of N-acetylaspartate (NAA) and water at two locations in the corpus callosum at 7T. Subjects were scanned at 7T with a 32-channel head coil using a DTS sequence that incorporated bipolar diffusion gradients within a point-resolved spectroscopic (PRESS) sequence. We demonstrate high resolution spectra and diffusion values consistent with previous reports at lower fields, demonstrating the feasibility of DTS at 7T to quantify a range of metabolites. Tractography Applications & Validation Hall B Tuesday 13:30-15:30 Kayako Matsuo1, Yu-Chun Lo2, Fang-Cheng Yeh3, Yi-Huan Wu4, Shen-Hsing Annabel Chen5, Wen-Yih Isaac Tseng1 1Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan; 2Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; 3Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States; 4Department of Medicine, National Taiwan University, Taipei, Taiwan; 5Division of Psychology, School of Humanities and Social Sciences, Nanyang Technological University, Singapore We measured the generalized fractional anisotropy (GFA) of the auditory nerve (AN) to bilateral Heschl's gyri via the corpus callosum (CC) using diffusion spectrum imaging (DSI). The individual language asymmetry was determined using fMRI. The left lateralized AN was found to be related to the leftward language asymmetry. The mild lateralization in the AN as well as the lower GFA in the CC tend to have relationship with the bilateral language function. The findings provide plausible evidence for the degree of conductivity of the AN as well as the CC in determining language lateralization/asymmetry between the hemispheres. Monica Bucci1, Maria Luisa Mandelli2, Jeffrey I. Berman, Bagrat Amirbekian3,4, Christopher Nguyen, Mitchel S. Berger5, Roland G. Henry 1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States; 2Department of Neuroradiology, Istituto Neurologico Carlo Besta, Milano, Italy; 3Radiology and Biomedical Imaging, University of California, San Francisco; 4UC Berkeley and UCSF Graduate Program in Bioengineering; 5Department of Neurological Surgery, University of California San Francisco There are different methods available for fiber tracking but only with few methods it is possible to quantify the accuracy and precision in clinical applications. We used preoperative HARDI data from patients with cerebral glioma to obtain corticospinal fiber tracts with deterministic and probabilistic Diffusion Tensor and Q-Ball fiber tracking algorithms using cortical and subcortical stimulation sites from IES as gold standard. The functional motor sites allows determination of the false negative rate of connectivity, which reflects the accuracy of the tractograms. The subcortical stimulation sites enable determination of the accuracy and precision of the course of the predicted CST. 1657. Diffusion Tensor Imaging of Basal Ganglia Output Fibers Mihaela Onu1, Uta Nicola Sboto-Frankenstein2, Patricia Gervai2, Greg Molnar3, Boguslaw Tomanek2 1Biophysics, University of Medicine "Carol Davila", Bucharest, Romania; 2National Research Council Institute for Biodiagnostics; 3Medtronic Inc. The current study was designed to investigate if it is feasible to use MRI Diffusion Tensor Imaging to visualize basal ganglia output fibers, in particular the Ansa Lenticularis (AL) and Lenticular Fasciculus (LF). Using the Globus Pallidus Internus (GPi) as a seed point, two fiber branches were identified. One originated in the dorsal aspect of the GPi and the second in the ventral aspect of the GPi. These two tracts may be indicative for the localization of the LF and AL respectively. Tzu-chen Yeh1, Chou-Ming Cheng1, Zong-Kai Hsu2, Jen-Chuen Hsieh2, Low-Ton Ho1 1Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan, Taiwan; 2Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan, Taiwan The spatial template of default-mode network (DMN) of sixty normal subjects has been constructed as five regions of interest (ROIs) as precuneus/posterior cingulate areas with the highest reproducibility. Multimodal approaches using BOLD-based fMRI and probabilistic DTI (pDTI) demonstrated the limited structural connectivity within each ROI within DMN correlates. By penetration maps of pDTI in twenty-two normal subjects, asymmetry of bilateral cingulum cortices implied preference of right posterior medial parietal regions for interpretation of internal/external environment with concert action of medial prefrontal areas, as one of the potential functions of DMN. 1659. Language Circuits of Human Brain: An Integrated Study of FMRI and Probabilistic DTI Zong-Kai Hsu1, Tzu-Chen Yeh2,3, Chou-Ming Cheng2, Wen-Jui Kuo4, Jen-Chuen Hsieh5 1Institute of Brain Science , National Yang Ming University , Taipei, Taiwan; 2Laboratory of Integrated Brain Research, Department of Medical Research & Education, Taipei Veterans General Hospital, Taipei, Taiwan; 3Institute of Brain Science , National Yang Ming University, Taipei, Taiwan; 4Institute of Neuroscience, National Yang Ming University, Taipei, Taiwan; 5Institute of Brain Science, National Yang Ming University, Taipei, Taiwan The language anatomical model proposed that Broca”¦s area located in the inferior frontal lobe and Wernicke”¦s area located in the superior temporal gyrus were connected through the arcuate fasciculus (AF). Hickok and Poeppel [1] and others recently proposed a dual stream model for auditory language processing. From the superior temporal gyrus, which is engaged in early cortical stages of speech perception, the system diverges into two processing streams. The aim of this study is to examine the language circuits of the dual stream model using visual perception by an integrated functional MRI (fMRI) and probabilistic diffusion tensor imaging (pDTI) method. 1660. Resolution-Dependent Differences in Fiber Tracking and Quantification of the Visual Pathways Jan Klein1, Peter Erhard2, Horst Karl Hahn1 1Fraunhofer MEVIS, Bremen, Germany; 2FB 2 (Chemistry) and Center of Advanced Imaging (CAI), Germany Fiber tracking and quantification of the visual pathways is still a challenging problem due distortions in the vicinity of the optic nerve, the small diameter of the bundle itself, crossing fibers in the optic chiasm and the capsula interna, the high curvature in the Meyers loop, and the discontinuity in the corpus geniculatum laterale. We examine how changes in the resolution of the DTI data sets influence the fiber tracking and quantification of the visual pathways, and show that an anisotropic resolution with a high coronal in-plane resolution should be preferred to an isotropic resolution with the same volume per voxel. Nico Dario Papinutto1, Jorge Jovicich1 1Center for Mind/Brain Sciences, University of Trento, Mattarello, Trento, Italy Diffusion tensor imaging (DTI) of in-vivo human brains is a technique that is becoming widely used to get insight into normal and abnormal white matter anatomical connectivity. Characterization of pathologies with fractional anisotropy (FA) losses have been done, both at voxel level and along tracts. A promising method to further improve the characterization of main streamlines consists on adding relaxation times measurements. We present a simple method for T1 quantification of white matter tracts using sequences available in most commercial scanners. Leonardo Cerliani1, Helen D'Arceuil2, Rajat M. Thomas3, Saad Jbabdi4, Christian M. Keysers1 1Neuroscience, University Medical Center Groningen, Neuroimaging Center, Groningen, Netherlands; 2Dept. of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, United States; 3Kapteyn Astronomical Institute, University of Groningen, Netherlands; 4FMRIB Centre, Univ. of Oxford, John Radcliffe Hospital, United Kingdom The connectivity of the macaque insula was analyzed by means of probabilistic tractography on diffusion-weighted images. The main aim was to detect and analyze trajectories of connectivity variation in this brain region, and to test the consistency of the results with the available anatomical evidence from animal literature. The employed method of laplacian eigenmaps was able to recover the expected gradual change in connectivity, and to discriminate this with the sharp transition in connectivity featured by the medial motor cortex Kerstin Pannek1,2, Jane Mathias3, James Taylor4, Parnesh Raniga5, Olivier Salvado5, Stephen Rose1,2 1Centre for Magnetic Resonance, University of Queensland, Brisbane, Queensland, Australia; 2UQ Centre for Clinical Research, University of Queensland, Brisbane, Queensland, Australia; 3School of Psychology, University of Adelaide, Adelaide, South Australia, Australia; 4Magnetic Resonance Imaging Unit, Royal Adelaide Hospital, Adelaide, South Australia, Australia; 5The Australian E-Health Research Centre, CSIRO, Brisbane, Queensland, Australia Structural connectivity of the brain using MR diffusion tractography has gained significant interest. A connectivity matrix of cortical connectivity may provide unique insight into brain organisation. We aimed to develop a method to determine the number of seeds required to obtain stable and reproducible connectivity, and to assess reproducibility over time. We employ a bootstrap approach for estimation of these parameters. While connectivity measures of some regions are highly reproducible over time, other connections show poor reproducibility. This study highlights the relationship between seed number and reproducibility of connectivity. Laura-Adela Harsan1, Csaba David2, Marco Reisert1, Susanne Schnell1, Jürgen Hennig1, Dominik von Elverfeldt1, Jochen F. Staiger2 1Department of Diagnostic Radiology, Medical Physics, University Hospital, Freiburg, Germany; 2Department of Neuroanatomy, Institute for Anatomy and Cell Biology, Freiburg, Germany The present study validates an in-vivo DT-MRI and FT protocol capable of identifying and characterizing the subtle connection pathways in the living mouse brain. The reconstructions of the thalamocortical projections derived from in-vivo DT-MRI were co-registered and correlated with 3D reconstructions of the fibers labeled with Phaseolus vulgaris-leucoagglutinin histological tracer, injected in the thalamus of the same animal. Good agreement between the deterministic and probabilistic tractography and the histological tracing was obtained in wild type and reeler mutant brains 1665. Challenges of Cortical Connectivity Measurements Using MR Tractography Ann Sunah Choe1,2, Yurui Gao1,3, Iwona Stepniewska4, Xia Li5, Zhaohua Ding5, Adam W. Anderson1,3 1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States; 2Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 3Vanderbilt University Institute of Imaging Science , Vanderbilt University, Nashville, TN, United States; 4Department of Psychology, Vanderbilt University, Nashville, TN, United States; 5Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States Study of anatomical connections often involves tracing fiber bundles to and from cortical areas of interest. The fiber tracking involved in such studies presents some unique problems. One of the challenges is the low diffusion anisotropy in gray matter, and the high directional uncertainty this causes. This problem is often circumvented by placing seed regions within the subcortical white matter, below the target regions of cortex. This approach risks tracking erroneous fibers due to limited spatial resolution and the complex interface between white and gray matter. In this abstract, the risk of such approaches is demonstrated by comparing DTI fiber pathways to histological sections of the corresponding regions. 1666. Piconmat.com Version 2.0: A Web-Based Probabilistic Tractography Data Service Chris James Rose1,2, David Morris1,2, Hamied Haroon1,2, Karl Embleton, 2,3, Nikos Logothetis1,4, Matthew Lambon Ralph3, Geoffrey J. Parker1,2 1Imaging Science and Biomedical Engineering, The University of Manchester, Manchester, United Kingdom; 2The University of Manchester Biomedical Imaging Institute, Manchester, United Kingdom; 3School of Psychological Sciences, The University of Manchester, Manchester, United Kingdom; 4Max Planck Institute for Biological Cybernetics, Tübingen, Germany We present version 2.0 of piconmat.com, a freely-available web-based system for exploring connectivity strengths between cortical and subcortical regions in a database of individuals. Connectivity strength is computed using diffusion MRI and probabilistic tractography. Version 2.0 is a significant update: connectivity strengths are presented in an interactive connectivity matrix and controls allow the user to study connectivity in individuals who meet certain criteria (e.g., right-handed males aged 25-50), and connectivity strengths for individuals belonging to different groups can be visually and quantitatively compared (e.g., right-handed males vs. females). 1667. Diffusion MRI and Anatomical Tracer Tractography of Association Pathways in the Same Brain Jennifer Campbell1, Ilana R. Leppert1, Stephen Frey2, Michael Petrides2, G. Bruce Pike1 1McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada; 2Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University Reliable in vivo diffusion MRI fibre tractography, particularly in association pathways, remains a difficult task due to a mismatch between the tract size and the image resolution achievable in a reasonable scan time. The objective of this study was to perform both diffusion MRI tractography and traditional tracer injection tract tracing in the association pathways of the same rhesus macaque monkey. Evaluation of diffusion MRI tract tracing in these association pathways can give us insight into its feasibility for mapping subtle connectivity in the human brain. Tractography Methods Hall B Wednesday 13:30-15:30 Christopher Tam Nguyen1, SungWon Chung2, Jeffrey I. Berman1, Roland G. Henry1 1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2Radiology, Brigham and Women's Hospital, Harvard University, Boston, MA, United States Fiber tracking (FT) based on diffusion MR has important applications for structural connectivity analyses of brain diseases and pre-operative FT of the brain. The residual bootstrap (RB) analysis on voxelwise DTI parameters is not appropriate to characterize the uncertainty in the large 3D regions defined by FT. Therefore, we will illustrate the appropriate implementation of RB to obtain the uncertainty of fiber tracking parameters (FTPs) such as number of streamlines (NOS). We validated our method with a Monte Carlo simulation showing that RB accurately estimated the SE of the NOS. Li-Wei Kuo1, Justin P. Haldar2, Yu-Chun Lo3, Cheng-Liang Liu1, Zhi-Pei Liang2, Wen-Yih Isaac Tseng1,4 1Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan; 2Department of Electrical and Computer Engineering, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 3Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; 4Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan Noise contamination is a significant problem in diffusion spectrum imaging (DSI) tractography, and previous work has proposed a statistical denoising algorithm to mitigate the effects of low signal-to-noise ratio. In this work, improvements to fiber orientation accuracy due to denoising were quantified using a systematic analysis of angular precision and dispersion metrics. Results show that the proposed denoising method significantly improves angular precision and dispersion. Furthermore, the tractography results demonstrate better reconstruction of white-matter structures using the denoised data. Future work will use the proposed denoising algorithm to improve spatial resolution and reduce scan time. J-Donald Tournier1,2, Fernando Calamante1,2, Alan Connelly1,2 1Brain Research Institute, Florey Neuroscience Institutes (Austin), Melbourne, Victoria, Australia; 2Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia Probabilistic streamlines algorithms are amongst the most promising methods for fibre-tracking, but are potentially subject to a number of deficiencies. These include a tendency to overshoot in highly curved regions, and to switch directions in crossing fibre regions. To address both of these issues, we propose a higher-order probabilistic streamlines algorithm, based on 2nd order integration over fibre orientation distributions (iFOD2), with a computational complexity similar to current first order methods. We demonstrate the advantages of the proposed iFOD2 algorithm on simulated data, and apply the method to in-vivo data. 1671. Tract-Based Parameterization of Local White Matter Geometry Peter Savadjiev1, Marek Kubicki1, Sylvain Bouix1, Gordon L. Kindlmann2, Martha E. Shenton1,3, Carl-Fredrik Westin4 1Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; 2Computer Science, University of Chicago, Chicago, IL, United States; 3Psychiatry, VA Boston Healthcare System, , Brockton , MA, United States; 4Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States Knowledge of fibre geometry and its variation along fibre tracts can be useful for the study of normal and pathological white matter. In this work we present a tract-based analysis of two recently introduced measures of fibre geometry, which compute fibre dispersion and fibre curving, directly from a diffusion tensor field and its gradient. These measures of fibre geometry are mapped and analysed along a parametric representation of fibre tracts. Such representations of fibre tract geometry are an important tool for the understanding of white matter structure. 1672. Towards Image-Dependent Safety Hulls for Fiber Tracking Sebastiano Barbieri1, Jan Klein1, Christopher Nimsky2, Horst K. Hahn1 1Fraunhofer MEVIS - Institute for Medical Image Computing, Bremen, Germany; 2Department of Neurosurgery, University Marburg, Marburg, Germany We make use of a DTI software model in order to systematically analyze the influence of noise, fiber bundle diameter, number of seed points and tensor anisotropy on the magnitude of fiber tracking errors. In our model we simulate image noise and partial volume artifacts. As a measure for fiber tracking errors we introduce a so called "safety radius". The safety radius is used to construct safety hulls, which are tubes that surround the tracked fibers and indicate their margin of error. We further analyze how fibers are spatially distributed inside a cylindrical fiber bundle during the tracking process. 1673. Atlas-Guided Automated Tract Reconstruction of the White Matter Anatomy Yajing Zhang1, Kenichi Oishi2, Michael I. Miller3, Jiangyang Zhang4, Susumu Mori2,5 1Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 3Center for Imaging Science, Johns Hopkins University, Baltimore, MD, United States; 4Radiology and Radiological Science, , Johns Hopkins University School of Medicine, Baltimore, MD, United States; 5F.M.Kirby Resarch Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States We performed comprehensive studies of human white matter anatomy using a novel atlas based automated fiber tracking system. 130 3-D ROIs were transformed from our brain atlas to the individual subject using non-linear transformations and used for automated fiber tracking. This approach allows exhaustive search of white matter bundles that consistently exist in the normal population. The method was validated by comparing to manual results by experts. We identified 29 short cortico-cortical association fibers in addition to well-defined major bundles. Probabilistic maps of such tracts in normalized space were constructed for the first time in the normal population. 1674. Global Fiber Tracking Becomes Practical Marco Reisert1, Irina Mader2, Constantin Anastasopoulus2, Susanne Schnell1, Valerij Kiselev1 1Medical Physics, University Hospital Freiburg, Freiburg, Baden-Wuerttemberg, Germany; 2Section of Neuroradiology, University Hospital Freiburg Local fiber tracking approaches are based on the 'walker' principle, the fibres are reconstructed path-by-path by small successive steps along the tracts. On the other hand global ideas try to reconstruct all fibres at once by optimizing a certain global objective. Local algorithms are fast but suffer from accumulated errors. Global methods have a more sound foundation but are very complex to optimize. This abstract presents an approach, which fuses both ideas while keeping their advantages. The experiments show that the approach is orders of magnitude faster than recent global approaches while improving the detection performance. 1675. Probabilistic Connectivity in Fibre Tractography Parya MomayyezSiahkal1, Kaleem Siddiqi1 1School of Computer Science, Centre for Intelligent Machines, McGill University, Montréal, Quebec, Canada We introduce a probabilistic connectivity index between two regions, based on diffusion MRI, by using a stochastic nonlinear differential equation to model the Brownian motion of water molecules in a medium. The model is linked to the physical basis of the diffusion process and leads to promising results on the MICCAI 2008 Fibre cup phantom. Our experiments yield highly curving fibre tracts without the need to impose thresholds on curvature or torsion or to eliminate false positives. An additional benefit is the algorithm's low computational complexity and the fact that its parameters are data-driven and are selected automatically. 1676. Analysis of Connectivity of Gray Matter Regions Using DTI and Graph Theory Amy Kuceyeski1, Ashish Raj1 1Radiology, Weill Cornell Medical College, New York, NY, United States The connectivity of gray matter regions in the brain via white matter tracts has recently become an area of wide interest due to the advances in imaging techniques that measure structural connections via white matter (DTI. The information that can be extracted from this modality has not yet been harvested fully due to its relative novelty; however some studies have proven its potential. We propose a computational methodology that utilizes DTI and structural images of the brain, graph theory, and clustering algorithms to explore regions of high connectivity and importance to overall connectivity in normal brains. Eizou Umezawa1, Yoshifumi Kuwayama2, Akihito Yamamoto2, Hikaru Masumoto2, Takashi Fukuba2, Masao Ohashi2, Keiko Terada2, Toshiaki Mori2, Yutaka Kinomura2, Kojiro Yamaguchi1, Masayuki Yamada1, Hirofumi Anno1, Kazuhiro Katada3 1School of Health Sciences, Fujita Health University, Toyoake, Aichi, Japan; 2Radiological Division, Fujita Health University Hospital, Toyoake, Aichi, Japan; 3Department of Radiology, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan Multi-Shelled QBI (MS-QBI) gives a new orientation distribution function based on the moment of the probability density function. We perform the fiber tracking of human brain based on MS-QBI and confirm the practicability of the method. We implement a simple procedure for streamline fiber trackings of pathways that encounter crossings. The pyramidal tract (PT) can be traced beyond the crossing with the superior longitudinal fasciculus by MS-QBI. The distinction between PT and the corpus callosum in the corona radiata is still difficult. Mustafa Okan Irfanoglu1,2, Lindsay Walker2, Carlo Pierpaoli2 1Department of Radiology, The Ohio State University, Columbus, OH, United States; 2NICHD, National Institutes of Health, Bethesda, MD, United States The distortions on phase-encoding direction of diffusion weighted images due to magnetic susceptibility and concomitant fields greatly affect the quality and consistency of tractography using on diffusion sequences. In this work, data from a healthy population were acquired in both Right-Left and Anterior-Posterior phase encoding directions and the effects of these distortions and EPI distortion correction were analyzed on specific fiber bundles. Results indicate tracts are greatly affected by these distortions and consistency and quality of the tracts are improved with correction and that this correction process should be part of typical diffusion sequences acquired for tractography purposes. 1679. On the Importance of Appropriate Fibre Population Selection in Diffusion Tractography Jonathan D. Clayden1, Chris A. Clark1 1Institute of Child Health, University College London, London, Greater London, United Kingdom While a lot of recent research in diffusion MRI has focussed on estimating the orientations of multiple fibre populations within image voxels, little attention has been given to the problem of how to effectively use this information in tractography. Typically a tractography algorithm selects a fibre direction to follow based on continuity, but we show here that a alternative approach based on prior knowledge gives substantially more robust results. Our technique is fully automated and uses a reference tract to inform the process. 1680. Quantitative Comparison of Automatic and Manual Tract Segmentation Methods Susana Muńoz Maniega1, James D. Bridson2, Wei Jie Jensen Ang2, Paul A. Armitage1, Catherine Murray3, Alan J. Gow3, Mark E. Bastin4, Ian J. Deary3, Joanna M. Wardlaw1 1Clinical Neurosciences, University of Edinburgh, Edinburgh, United Kingdom; 2Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, United Kingdom; 3Psychology, University of Edinburgh, Edinburgh, United Kingdom; 4Medical Physics, University of Edinburgh, Edinburgh, United Kingdom We compare probabilistic neighbourhood tractography (PNT), an automatic tract segmentation method, with a well accepted tractography method using manual seed placement and multiple region-of-interest (ROI) constraints. Tracts were segmented in the same data set using both methods and mean values of FA and MD compared. Mean differences between PNT and ROI methods were ≤10%, comparable with the reproducibility obtained when ROI are manually placed by different operators. PNT segmentation showed a reasonable agreement with the more conventional ROI tract segmentation method, with the advantage of removing operator dependency.
Christian Ros1, Daniel Güllmar1, Juergen R. Reichenbach1 1Medical Physics Group, Institute for Diagnostic and Interventional Radiology, Jena University Hospital, Jena, Germany, Jena, Thuringia, Germany In recent years various fiber tractography methods have been evolved. Although these resulting tractograms offers plenty of information, they are rarely used in clinical routine due to the fact that processing is often time-consuming and an experienced operator is essential to obtain good results. To overcome this limitations cluster analysis can be employed to partition fiber tracts into clusters through comparison of tract-specific features or similarity measures. The aim of this study was to develop a new combined similarity measure that combines a shape based distance measure with other distance measures. 1682. Visualizing and Exploring Tractograms Via Two-Dimensional Connectivity Maps Radu Jianu1, Cagatay Demiralp1, David H. Laidlaw1 1Brown University, Providence, RI, United States We introduce a circular graph visualization of tract projections in a framework that uses two-dimensional map representations for exploring connectivity in the brain. Expert feedback indicates that it can be useful for understanding connectivity densities and configurations. 1683. Visualization of Intrarenal Water Transport by Diffusion Tensor Tractography Michael Pedersen1, Anders B. Lųdrup1, Kristian Karstoft1, Eva A. Nielsen2, Mette K. Hagensen2, Peter A. Nielsen2, Andreas Stavropoulos3, Bente Jespersen4, Steffen Ringgaard1, Morten Smerup2 1MR Research Center, Aarhus University Hosptial, Aarhus, Denmark; 2Institute of Clinical Medicine, Aarhus University Hosptial, Aarhus, Denmark; 3Dept. of Periodontology, Aarhus University, Aarhus, Denmark; 4Department of Nephrology, Aarhus University Hospital, Aarhus, Denmark The aim of this study is to investigate if DTI can be used for imaging the principal route of free water in the kidney, and we hypothesize that this route can act as an indirect representation of the segments of nephrons going centripetally from the renal parenchyma to the collecting ducts. The orientation of medullary diffusion anisotrophy was visualized using a proposed DTI tractography method MARDI Hall B Thursday 13:30-15:30 1684. A Monte-Carlo Approach for Estimating White Matter Density in HARDI Diffusion Data Parnesh Raniga1, Kerstin Pannek2,3, Jurgen Fripp1, David Raffelt1, Pierrick Bourgeat1, Oscar Acosta1, Donald Tournier4, Allan Connelly4, Stephen Rose2,3, Olivier Salvado1 1CSIRO Preventative Health National Research Flagship ICTC, The Australian e-Health Research Centre, Brisbane, Queensland, Australia; 2Centre for Magnetic Resonance, University of Queensland, Brisbane, Queensland, Australia; 3UQ Centre for Clinical Research, University of Queensland, Brisbane, Queensland, Australia; 4Brain Research Institute, Melbourne, Victoria, Australia The abstract is about using visitation maps to perform quantitative analysis. 1685. On the Behavior of DTI and Q-Ball Derived Anisotropy Indices Klaus H. Fritzsche1, Bram Stieltjes2, Frederik B. Laun3, Hans-Peter Meinzer1 1Division of Medical and Biological Informatics, German Cancer Research Center, Heidelberg, B-W, Germany; 2Division of Radiology, German Cancer Research Center; 3Division of Medical Physics, German Cancer Research Center Anisotropy indices in diffusion imaging have never been systematically analyzed under conditions of heterogeneous fiber configurations. Furthermore, q-ball imaging indices have so far not been evaluated with respect to accuracy, precision, b-value dependency and contrast-to-noise ratio (CNR). This study performed a systematic analysis using Monte Carlo simulations and measurements in crossing fiber phantoms. The GFA (reconstructed with solid angle consideration) showed the lowest dependency on b-value and the best results regarding accuracy and precision. Its behavior in crossing fiber voxels was also preferable. Main drawback was its low CNR, especially in low anisotropy fibers. 1686. Analytical Q-Ball Imaging with Optimal λ-Regularization Maxime Descoteaux1, Cheng Guan Koay2, Peter J. Basser2, Rachid Deriche3 1Computer Science, Université de Sherbrooke, Sherbrooke, Québec, Canada; 2National Institute of Child Health and Human Development, Bethesda, MD, United States; 3INRIA Sophia Antipolis - Méditerranée, Sophia Antipolis, France We present analytical q-ball imaging with optimal Generalized Cross Validation (GCV)-based regularization. The method is the optimal extension of the standard analytical q-ball imaging, normally implemented using a fixed regularization λ = 0.006. QBI with optimal λ shows a distinct advantage in generalized fractional anisotropy (GFA) computation when the underlying structure is complex and in single fiber parts of real data. Jelle Veraart1, Wim Van Hecke2,3, Dirk Poot1, Ines Blockx4, Annemie Van Der Linden4, Marleen Verhoye4, Jan Sijbers1 1Vision Lab, University of Antwerp, Antwerp, Belgium; 2Department of Radiology, Antwerp University Hospital, Antwerp, Belgium; 3Department of Radiology, University Hospitals of the Catholic University of Leuven, Leuven, Belgium; 4Bio Imaging Lab, University of Antwerp, Antwerp, Belgium Due to the presence of complex cellular microstructures in the brains white matter, the diffusion weighted signal attenuation with respect to the b-value can not accurately be approximated by the monoexponential function assumed by DTI. Because of this, the estimation of the diffusion coefficient and the associated diffusion parameters depend on the b-value of the acquisition. The recently proposed higher order DKI model fits the signal attenuation more properly as a result of which, as demonstrated in this study, a more accurate estimation of the diffusion parameters is obtained. In addition the parameter estimation appears b-value independent. 1688. Anomalous Diffusion Tensor Imaging Matt G. Hall1, Thomas Richard Barrick2 1Dept of Computer Science, University College London, London, United Kingdom; 2Centre for Clinical Neuroscience, Division of Cardiac & Vasculas Sciences, St Georges, University of London, London, United Kingdom The theory of anomalous diffusion applied to diffusion imaging predicts a stretched-exponential form for the decay of diffusion-weighted signal with b-value. We generalise this to consider diretional anisotropy of the parameters of the stretched-exponential form. The resulting technique (anomalous diffusion tensor imaging) provides estimates of tensors describing diffusivity and tissue heteroegeneity in each scan voxel. We apprly the technique to healthy in vivo data and use the resulting tensors to infer tissue microstructure perform streamline tractography in the corpus callosum. Marta Morgado Correia1,2, Guy B. Williams2 1MRC Cognition and Brain Sciences Unit, Cambridge, Cambridgeshire, United Kingdom; 2Wolfson Brain Imaging Centre, Cambridge, Cambridgeshire, United Kingdom In this work we show how spectral decomposition of a 4-rank generalised diffusion tensor can be used to characterise brain structure, including the definition of two metrics of anisotropy that do not depend on the arbitrary choice of a normalising function and its parameters. A P. Hosseinbor1, J O. Fleming2, Y-C Wu3, A A. Samsonov4, A L. Alexander 1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Neurology, University of Wisconsin-Madison; 3Dartmouth College; 4Radiology, University of Wisconsin-Madison In HYDI, Po is conventionally estimated by using signal measurements in all shells (Poall), which requires long scan time. However, the highest diffusion-weighting measurements are likely to contribute most heavily to restricted diffusion (RD) signal. Thus, an alternative, faster approach for characterizing RD would be to use signal measurements only in outermost shell (Poouter). In this work, we compare both Poall and Poouter approaches in NAWM from MS patients and WM in a control group. We show that both approaches yield similar statistical properties for characterizing RD, which suggests Poouter is both adequate and faster than using full q-space measurements. 1691. Combined DTI/HARDI Visualization Vesna Prckovska1, Tim H.J.M. Peeters1, Markus van Almsick1, Anna Vilanova1, Bart ter Haar Romeny1 1Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands We present a novel visualization framework that unifies the models from DTI and HARDI, using a classification scheme for model selection. The data is represented by diffusion tensors or fibers in the Gaussian and HARDI glyphs in the non-Gaussian areas. We exploit the capabilities of modern GPU to optimize the rendering performance and visual quality of the glyphs. All of the visualization parameters are controlled by the user in real time. Different color coding on the glyphs enhance the anisotropy information or highlight maxima. This is the first attempt to give fast and intuitive insight into the complex HARDI data. 1692. Determination of Local Fibre Configuration Using Bayesian Neighbourhood Tract Modeling Thomas Glyn Close1,2, Jacques-Donald Tournier1,3, Fernando Calamante1,3, Leigh A. Johnston2,4, Iven Mareels2, Alan Connelly1,3 1Brain Research Institute, Florey Neuroscience Institutes (Austin), Melbourne, Victoria, Australia; 2School of Engineering and NICTA VRL, University of Melbourne, Melbourne, Victoria, Australia; 3Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia; 4Howard Florey Insitute, Florey Neuroscience Institutes (Parkville), Melbourne, Victoria, Australia We present a new method for characterising white matter fibre configurations within local neighbourhoods. Instead of single-voxel based models of fibre orientations represent the complete tract configuration within a local neighbourhood (eg. 3x3x3 voxels) via a rich tract-segment model. By fitting multiple tracts simultaneously, this approach utilizes the probability of surrounding tracts to improve the fit of each tract. Yuliya Kupriyanova1, Oleg Posnansky2, N. J. Shah2,3 1Medical Imaging Physics, Institute of Neuroscience and Medicine - 4, Forschungzentrum Juelich, Juelich, Germany; 2Medical Imaging Physics, Institute of Neuroscience and Medicine - 4 , Forschungzentrum Juelich, Juelich, Germany; 3Department of Neurology, Faculty of Medicine, RWTH Aachen University, Aachen, Germany Imperfections in the diffusion-weighted (DW) gradients may cause errors in the estimation of diffusion parameters. We present results demonstrating the influence of these errors in the accuracy of fibre orientation density function (ODF) estimation. A DW gradient calibration scheme, used to mitigate DW gradient errors, is also described. We compared the reconstructed fibre ODFs from two datasets, acquired in vivo with and without the application of the calibration scheme and calculated the statistical efficiency of the unbiased fibre ODF estimators for these datasets. It is shown that the calibration procedure can significantly improve results of the fibre ODF estimation. 1694. Riemannian Median and Its Applications for Orientation Distribution Function Computing Jian Cheng1,2, Aurobrata Ghosh1, Tianzi Jiang2, Rachid Deriche1 1INRIA Sophia Antipolis, Sophia Antipolis, Valbonne, France; 2Institute of Automation, Chinese Academy of Sciences, Beijing, China In this work, we prove the unique existence of the Riemannian median in the space of Orientation Distribution Fuction. Then we explore its two potential applications, median filtering and atlas estimation. 1695. Impact of Outliers in DTI and Q-Ball Imaging - Clinical Implications and Correction Strategies Michael Andrew Sharman1, Julien Cohen-Adad2, Maxime Descoteaux3, Arnaud Messé4,5, Habib Benali4,5, Stéphane Lehericy6,7 1UMR-S975, CRICM-UPMC/Inserm, Paris, Īle-de-France, France; 2Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, United States; 3Department of Computer Science, Sherbrooke University, Québec, Canada; 4UMR-S678, UPMC/Inserm, Paris, France; 5IFR49, Paris, France; 6Centre for NeuroImaging Research (CENIR), Hospital Pitié-Salpźtričre , Paris, France; 7UMR-S975, CRICM-UPMC/Inserm, Paris, France Corrupted images within acquired diffusion weighted MRI data can have an impact on the estimation of the tensor (in diffusion tensor imaging) and diffusion ODF (in q-ball imaging). In this study we performed a series of simulations and real data analyses to quantify this impact on derived metrics such as fractional anisotropy (FA) and generalised FA. From the results of these invetigations, we propose processing strategies to detect and correct corruption artifacts arising from large, unpredicatable signal variations. Bennett Allan Landman1,2, Hanlin Wan2,3, John A. Bogovic3, Peter C. M. van Zijl, 2,4, Pierre-Louis Bazin5, Jerry L. Prince, 2,3 1Electrical Engineering, Vanderbilt University, Nashville, TN, United States; 2Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States; 3Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States; 4F.M. Kirby Center, Kennedy Krieger Institute, Baltimore, MD, United States; 5Radiology, Johns Hopkins University, Baltimore, MD, United States Q-ball imaging offers the potential to resolve the DTI crossing-fiber problem by acquiring additional diffusion sensitized scans. Yet, practical constraints limit its widespread adaptation in clinical research. Recently, compressed sensing has characterized regions of crossing fibers using traditional DTI data (i.e., low b-value, 30 directions). Here, we compare q-ball and compressed sensing in simulated and in vivo crossing-fibers. Compressed sensing estimates intra-voxel structure with greater reliability than traditional q-ball while using only 13% of the scan time. Hence, compressed sensing has the potential to enable clinical study of intra-voxel structure for studies that have hitherto been limited to tensor analysis. 1697. Compressed Sensing Based Diffusion Spectrum Imaging Namgyun Lee1, Manbir Singh2,3 1Biomedical Engieering, University of Southern California, Los angeles, CA, United States; 2Biomedical Engineering; 3Radiology, University of Southern California Reconstruction of the PDF and ODF by Compressed Sensing based diffusion Spectrum Imaging method 1698. Accelerated Diffusion Spectrum Imaging in the Human Brain Using Compressed Sensing Marion Irene Menzel1, Kedar Khare2, Kevin F. King3, Xiaodong Tao2, Christopher J. Hardy2, Luca Marinelli2 1GE Global Research, Munich, Germany; 2GE Global Research, Niskayuna, NY, United States; 3GE Healthcare, Waukesha, WI, United States We developed a new method to accelerate diffusion spectrum imaging (DSI) in the human brain using compressed sensing (CS) to an extent that can be tolerated in volunteers and patients. We performed simulations and real experiments in brains of healthy volunteers, where we undersampled q-space with different sampling patterns and reconstructed it using CS. We could demonstrate that even with acceleration up to factors of R = 4 essential information on diffusion, such as orientation distribution function (ODF) and diffusion coefficients are retained. Shortening DSI acquisitions significantly by means of CS would open up the door to new contrasts, which are truly based on underlying tissue properties. 1699. Diffusion Histogram as a Marker of Fiber Crossing Within a Voxel Bryce Wilkins1, Manbir Singh2 1Biomedical Engineering, University of Southern California, Los Angeles, CA, United States; 2Radiology and Biomedical Engineering, University of Southern California, Los Angeles, CA, United States A simulation and experimental study of the histogram generated from the normalized diffusion signal measured along multiple gradient directions is presented. Voxels exhibiting an FA of at least 0.8 are identified as representative of single fiber voxels, and used to derive diffusion signals for multiple fiber crossings, in the range 0-90deg. The results illustrate how the histogram changes systematically with crossing fibers within a voxel, and suggests that the histogram can be used as a marker of the number of fibers within a voxel, and their relative orientation. Diffusion in Animal Models Hall B Monday 14:00-16:00 Andreas Lemke1, Patrick Heiler1, Bram Stieltjes2, Andreas Neumann3, Lothar Rudi Schad1 1Deparmtent of Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Deparmtent of Radiology, German Cancer Research Center, Heidelberg, Germany; 3Department of Molecular Neurobiology, German Cancer Research Center, Heidelberg, Germany A comparison of the SNR in DTI images acquired with a cryogenic coil and a room temperature (RT) surface coil and a comparison performed by qualitative assessment of the calculated fractional anisotropy (FA)-maps at different spatial resolutions were performed on mice brain at a 9.4 T animal scanner. The SNR of the cryogenic coil was about threefold higher compared to the SNR of the RT surface coil and the quality of the FA-maps acquired with a high in plane resolution and the cryogenic coil were significantly improved compared to the RT-coil. 1701. Characterization of White Matter Maturation in Cats: Diffusion Spectrum Imaging Tractography Qin Chen1,2, Emi Takahashi3, Guangping Dai1, Ellen Grant, 1,3 1Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Martinos Center for Biomedical Imaging, Charlestown, MA, United States; 2Department of Neurology, West China Hospital of Sichuan Univeristy, Chengdu, Sichuan, China; 3Divison of Newborn Medicine, Department of Medicine and Department of Radiology, Children”Æs Hospital Boston, Harvard Medical School, Boston, MA, United States We have shown that at postnatal day (P) 35 kittens, the degrees of myelination varied in white matters in different brain areas (Takahashi et al., 2009). Our purpose of current study was to quantify the FA and ADC values on different fiber tracts in this specific developmental phase of juvenile kitten to characterize regional difference in degrees of maturation, and to compare these values between P35 (pediatric). Using high-resolution diffusion spectrum imaging (DSI) tractography, we successfully imaged the 3-dimensional structure of the cortical and subcortical pathways in P35 cats. 1702. DTI Study of Development and Aging of the Optic Nerve in Rhesus Monkeys Yumei Yan1, Longchuan Li2, Govind Nair2, Todd Preuss3, Mar Sanchez4,5, Mark Wilson3, Xiaoping Hu2, James Herndon3, Xiaodong Zhang1 1Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States; 2biomedical engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, United States; 3Neuroscience Division, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States; 4Psychiatry & Behavioral Sciences, School of Medicine, Emory University, Atlanta, GA, United States; 5Psychobiology Division, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States Non-human primate model was employed to access the optic nerve (ON) development and aging with Diffusion tension imaging (DTI). ADC and FA evolution in the ON of monkeys was investigated systematically. Significant changes were found between 21 months with 6 years of age, but not observed in the ON in early development. Furthermore, DTI revealed age-related changes in older rhesus monkeys that may represent axonal and myelin degeneration. DTI may provide a means to evaluate ON disorders or injury. 1703. Astrocytic Aquaporin-4 Contributes Significantly to Water Mobility in the Rat Brain Andre Obenaus1,2, Stephan Ashwal3, Jerome Badaut Badaut3 1Radiation Medicine, Loma Linda University, Loma Linda, CA, United States; 2Radiology, Loma Linda University, Loma Linda , CA, United States; 3Pediatrics, Loma Linda University, Loma Linda, CA, United States Diffusion weighted MRI is widely used in clinical diagnosis. To date the underlying molecular mechanism responsible for changes in the apparent diffusion coefficient (ADC) are poorly understood. Using small interference RNA directed against the astrocytic water channel, acqueporin-4 (AQP4), we were able to demonstrate a 50% decrease in ADC values when AQP4 expression was silenced (25%). Thus, astrocytic AQP4 contributes significantly to the ADC values in normal rodent brain. These results suggest new possibilities for interpreting ADC values in normal brain and under pathological conditions. 1704. Anatomical Phenotyping of a Mouse Model with Known White Matter Abnormalities Jacob Ellegood1, Ameet S. Sengar2, M W. Salter2, S E. Egan3, Jason P. Lerch1, R M. Henkelman1 1Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada; 2Neuroscience and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada; 3Developmental Biology, Hospital for Sick Children, Toronto, Ontario, Canada Anatomical phenotyping in mouse has shown to be useful for determining small changes in volume. Similarly, Diffusion Tensor Imaging (DTI) of fixed mouse brain has been useful in assessing development and genetic differences in wild type and knockout mouse models. The purpose of this study was to determine both the volume and white matter structural changes in a mouse model with known white matter abnormalities. While some of the fractional anisotropy changes can be attributed to corresponding decreases in the volume, some structures and regions have changes that would go unnoticed if only volume or fractional anisotropy was measured. 1705. Fractional Anisotropy Changes Following Blood Brain Barrier Disruption Ashley D. Harris1,2, Linda B. Andersen, 2,3, Henry Chen, 2,4, Pranshu Sharma2, Richard Frayne, 2,3 1School of Psychology, CUBRIC, Cardiff University, Cardiff, United Kingdom; 2Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, Alberta, Canada; 3Clinical Neurosciences and Radiology, Univerisity of Calgary, Calgary, Alberta, Canada; 4Physics, Univerisity of Calgary, Calgary, Alberta, Canada The evolution of FA is examined in a canine model following blood brain barrier disruption with hypertonic mannitol solution. White matter and grey matter show different FA responses to blood brain barrier disruption. White matter decreases, while grey matter showed significant increases. With additional understanding, FA may assist in determining the integrity of the blood brain barrier. 1706. Early Diffusion Changes Following Controlled Cortical Impact Injury on a Rat Model Jiachen Zhuo1,2, Su Xu1,2, Jennifer Racz3, Da Shi1,2, Gary Fiskum3, Rao Gullapalli1,2 1Radiology, University of Maryland School of Medicine, Baltimore, MD, United States; 2Core for Translational Research in Imaging at Maryland (C-TRIM), University of Maryland School of Medicine, Baltimore, MD, United States; 3Anesthesiology and the Center for Shock Trauma and Anesthesiology Research, University of Maryland School of Medicine, Baltimore, MD, United States The understanding of tissue alterations at an early stage following traumatic brain injury (TBI) is critical for injury management and prevention of more severe secondary damage. In this study, we investigated the early changes in tissue water diffusion at 2 hours and 4 hours following mild to moderate controlled cortical impact injury on a rat model. Our study indicates a distance effect from the site of injury and suggests a therapeutic window of about 2-3 hours to limit the cascade of events that may lead to secondary injury. 1707. A Longitudinal Study of DTI in a Nonhuman Primate Model of Neuro-AIDS Chun-xia Li1, Xiaodong Zhang1, Yingxia Li1, Amelia Komery2, Francis J. Novembre3, James G. Herndon2 1Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA,30329, United States; 2Divisions of Microbiology and Immunology, Yerkes National Primate Research Center, Emory University, Atlanta, GA,30322; 3Divisions of Neuroscience, Yerkes National Primate Research Center, Emory University, Atlanta, GA,30322 DTI has been proposed as a quantitative marker of the neurological status of HIV+ patients. In this study, DTI imaging was used to longitudinally detect white matter abnormalities in whole brain and specific regions of Simian immunodeficiency virus (SIV)-infected monkeys, a reduction in FA and an increase in MD were observed evidently after viral inoculation and whole-brain FA changes correlated significantly with CD4 depletion. Findings from this investigation support the use of DTI for measurement of HIV associated neuropathologic changes. Further longitudinal study is needed to investigate the validation of DTI measures as a marker for disease progression. 1708. Hyperammonemia and Edema: A DTI Study in the Adult Rat Brain Nicolas Kunz1,2, Cristina Cudalbu1, Yohan Van de Looij1,2, Petra Hüppi2, Stephane Sizonenko2, Rolf Gruetter1,3 1Laboratory of functional and metabolic imaging (LIFMET), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 2Division of Child Growth &Development, University of Geneva, Geneva, Switzerland; 3Department of Radiology, University of Geneva & Lausanne, Geneva & Lausanne, Switzerland Ammonia is a neurotoxin that is implicated in the pathogenesis of hepatic encephalophaty, which is reported to be responsible for brain edema. It is not yet clear whether brain edema is mostly vasogenic or cytotoxic. The aim of this study was to assess the effects of hyperammonemia on the rat brain by using DTI at 9.4T. This study shows a rapid increase of the ventricle size during the three first hours of infusion along with a decrease in ADC. As the ventricle size gets stabilized after 6h, the ADC keeps on decreasing, indicating the formation of mild cytotoxic edema. Stephan William Anderson1, Jorge A. Soto1, Holly N. Milch1, Hernan Jara1 1Radiology, Boston University Medical Center, Boston, MA, United States The purpose of this study was to compare the ADC values obtained using pulsed field gradient (PFG) and correlation time diffusion (CT-D) techniques in a mouse model of steatohepatitis at 11.7T. C57BL/6 mice fed a methionine-deficient choline-deficient (MCD) diet to induce steatohepatitis were sacrificed intermittently throughout this period for ex vivo liver imaging. A comparison of the parametric maps and whole sample histograms generated by the PFG and CTD techniques shows excellent agreement between the two diffusion techniques. In all cases CT-D parametric maps had significantly higher SNR and the histogram width was narrower than those generated using PFG technique. Blood Flow in Animal Models Hall B Tuesday 13:30-15:30 1710. Blood-Flow MRI of Non-Human Primate (Baboon) Retina Hsiao-Ying Wey1, Jinqi Li1, Jiongjiong Wang2, Sung-Hong Park1, Timothy Q. Duong1 1Research Imaging Institute, UT Health Science Center at San Antonio, San Antonio, TX, United States; 2Radiology, University of Pennsylvania, Philadelphia, PA, United States Quantitative blood flow measurement of the retina is critically important as many retinal diseases could perturb basal blood flow and blood flow responses to stimulations. In this study, we developed and applied the pseudo-continuous ASL to improve ASL contrast, and systematically explored blood-flow MRI of the retina in anesthetized baboon on a human clinical scanner. Anesthetized baboons were used to exclude movement artifacts such that we could focus on evaluating hardware feasibility and imaging parameters for high-resolution quantitative BF imaging of the retina as a first step toward evaluating potential human applications. 1711. Quantitative Measurement of Cerebral Blood Flow with High Sensitivity in Mice at 9.4T Bing Wen Zheng1, Philip Lee1, Xavier Golay1 1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, A*STAR (Agency for Science, Technology and Research), Biopolis, Singapore The aim of this study was to develop a practical and robust perfusion measurement with high sensitivity and stability in the mouse brain at high magnetic field strength, via the combination of flow-sensitive alternating inversion recovery (FAIR) and single-shot k space-banded gradient- and spin-echo (kbGRASE). To estimate the influence of physiological parameters on the precision and reproducibility of CBF measurements, changes in anesthesia regime, hypercapnia and body temperature were performed. Tracey Anne Baskerville1, Christopher McCabe1, Jim Patterson2, Juan Chavez3, I Mhairi Macrae1, William M. Holmes1 1Glasgow Experimental MRI Centre, University of Glasgow, Glasgow, Lanarkshire, United Kingdom; 2Institute of Neurological Sciences, Southern General Hospital, Glasgow, United Kingdom; 3Discovery Translational Medicine, Wyeth Research, Collegeville, PA, United States Arterial spin labelling (ASL) has provided some valuable insight into cerebral perfusion in stroke research. ASL has the advantages of being non-invasive, allows repeated scanning in the same subject and can generate fully quantitative cerebral blood flow (CBF) measurements; however it requires further validation in rodent stroke models. We modified a published ASL technique (Moffat et al, 2005) and validated it against an established autoradiographic technique using the SPECT ligand, 99mTC-D, L-Hexamethylpropyleneamine (99mTc-HMPAO) in a rodent stroke model. We found that relative CBF estimates in cerebral regions of interest generated from ASL and autoradiography were closely matched throught MCA territory and ASL was able to accurately detect reductions in CBF in ischaemic tissue. 1713. Quantitative CBF MRI of Anesthetized Baboon Using Pseudo-Continuous ASL Hsiao-Ying Wey1,2, Jinqi Li1, Lisa Jones3, M Michelle Leland3, C Akos Szabo4, Jiongjiong Wang5, Peter T. Fox1, Timothy Q. Duong1,2 1Research Imaging Institute, UT Health Science Center at San Antonio, San Antonio, TX, United States; 2Radiology, UT Health Science Center at San Antonio, San Antonio, TX, United States; 3Laboratory Animal Resources, UT Health Science Center at San Antonio, San Antonio, TX, United States; 4Neurology, UT Health Science Center at San Antonio, San Antonio, TX, United States; 5Radiology, University of Pennsylvania, Philadelphia, PA, United States This study reports the implementation and optimization of a pseudo-continuous arterial-spin-labeling technique for non-human primate (baboon) research on a Siemens 3T TIM-Trio. High-contrast basal cerebral-blood-flow (CBF) images were obtained in 2 mins at 2x2x5 mm resolution. CBF of gray matter and white matter was analyzed for two commonly used anesthetics: isoflurane and ketamine. Moreover, CBF-based fMRI, obtained with a 7-s resolution, showed robust hypercapnia-induced CBF changes. This technology is expected to provide a non-invasive means to study physiology, function, and neurovascular coupling for non-human primate research. 1714. Pulsed Arterial Spin Labeling of Hypo- And Hyperventilated Mice Tom Dresselaers1, Wouter Oosterlinck2, Wim Robberecht3, Paul Herijgers2, Uwe Himmelreich1 1Biomedical NMR unit - MoSAIC, K.U.Leuven, Leuven, Belgium; 2Experimental Cardiac Surgery, K.U.Leuven, Leuven, Belgium; 3Exp. Neurology, K.U.Leuven, Leuven, Belgium Arterial spin labeling methods have been widely used to study perfusion of the brain in rats and, to some extent, in mice. To study the cerebral vascular response animals are challenged with gas mixtures to induce hypercapnia or hypoxia. However, in free-breathing animals partial respiratory compensation can not be excluded. Additionally, different respiratory levels have been noted depending on strain or transgenic model or age.We demonstrate in this study how hyper and hypocapnia can be obtained in ventilated mice by adjusting the ventilation rate and tidal volume. CBF was monitored using FAIR-ASL of the brain during this protocol. 1715. Correction for the T2 Effect of Contrast Agent on Absolute CBV Quantification Using VASO Fu-Nien Wang1, Chien-Chung Chen1, Yi-Chun Wu1, Chou-Ming Cheng2, Tzu-Chen Yeh2 1Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, Taiwan; 2Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan, Taiwan Absolute cerebral blood volume (aCBV) can be assessed by utilizing the signal difference of vascular space occupancy (VASO) sequence before and after injection of T1 shortening contrast agent. We propose an alternative method to reduce the T2 effect when using relative long TE. Pre and post T1 fitting were used to reconstruct IR images without the post contrast T2 shortening effect. Experiments on rat model were conducted to investigate the feasibilities. Jeff D. Winter1, Stephanie Dorner2, Joseph A. Fisher3,4, Keith St. Lawrence5,6, Andrea Kassner1,7 1Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Respiratory Therapy, University Health Network, Toronto, Ontario, Canada; 3Anaesthesiology, University Health Network, Toronto, Ontario, Canada; 4Physiology, University of Toronto, Toronto, Ontario, Canada; 5Imaging Division, Lawson Health Research Institute, London, Ontario, Canada; 6Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 7Medical Imaging, University of Toronto, Toronto, Ontario, Canada The swine model is an alternative to non-human primates for neuroimaging and may be suitable for studying pediatric cerebrovascular disorders. The aim of this study was to characterize swine cerebrovascular development using BOLD cerebrovascular reactivity (CVR) and ASL cerebral blood flow (CBF). We acquired data from 13 juvenile (1-12 wk) pigs. BOLD-CVR measurements exhibited a significant logarithmic increase with body weight (Pearson r>0.81 and p<0.005 for all brain regions); whereas, baseline CBF was not related to body weight. Understanding these cerebrovascular changes will benefit future developmental studies using the swine as a translational model for cerebrovascular disease. Dynamic Contrast Enhancement MRI Hall B Wednesday 13:30-15:30 1717. The Saline Bolus as an MR Contrast Agent Kenneth K. Kwong1, Y Iris Chen1, Suk-Tak Chan1,2, David A. Chesler1 1MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States; 2Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong We obtained ΔR2* maps of a saline bolus dilution of the blood of the brain. Since the MR sensitivity to the dilution of deoxyhemoglobin was small, we also investigated the ΔR2* signal of a saline bolus diluting monocrystalline iron oxide nanoparticle (MION) preloaded into the vascular system. Our preliminary data showed that while the dilution of MION by saline generated ΔR2* maps similar to reference rCBV maps made by steady state MION imaging, the saline dilution of blood needed to take into account the presence of both the rCBV and OEF components of the BOLD signal. 1718. Early Time Points Perfusion Imaging Kenneth K. Kwong1, Timothy G. Reese1, Koen Nelissen1, Ona Wu2, Suk-Tak Chan1, Benner Thomas1, Joseph B. Mandeville1, Mary Foley1, Wim Vanduffel1, David A. Chesler1 1MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States; 2MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital,, Charlestown, MA, United States We investigated the feasibility of making relative cerebral blood flow (rCBF) maps from MR images acquired with short TR by measuring the initial rate of Gd-DTPA arriving within a time window smaller than the tissue mean transit time τ. We named this rCBF measurement technique utilizing the early data points of the bolus the early time points method (ET). ET offered rCBF results of reasonable gray-white flow contrast. Better brain coverage for ET can be obtained by applying the SIR-EPI technique. Attention was paid to the noise problem around the time of arrival (TOA) of the contrast agent. Claire Foottit1, Greg O. Cron2, Thanh Binh Nguyen2,3, Matthew J. Hogan2,3, Ian Cameron, 12 1Carleton University, Ottawa, Ontario, Canada; 2Diagnostic Imaging, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; 3University of Ottawa, Ottawa, Ontario, Canada For quantitative DCE-MRI of the human brain, the Gd concentration-vs-time in the superior sagittal sinus gives the venous output function (VOF). The VOF can be used to correct errors in the arterial input function, which is crucial for accurate estimation of perfusion parameters. For measuring the VOF, MR signal phase has several advantages over MR signal magnitude: superior SNR; linearity with Gd concentration; and insensitivity to blood flow, partial volumes, and flip angle variations. This work showed that phased-derived VOFs have improved accuracy and precision compared with magnitude-derived VOFs for multislice (2D) DCE-MRI studies of the human brain (n=28). 1720. Accuracy of T1-Fitting for Pharmacokinetic Analysis of Dynamic Contrast-Enhanced MRI Paul Wessel de Bruin1, Maarten J. Versluis1, Erlangga Yusuf2, Monique Reijnierse1, Iain Watt1, Matthias J P van Osch1 1Radiology Department, Leiden University Medical Center, Leiden, Netherlands; 2Rheumatology Department, Leiden University Medical Center, Leiden, Netherlands The accuracy of Arterial Input Function and tissue response curve calculation in Dynamic Contrast-Enhanced MRI and Pharmacokinetic Analysis can be improved by calculating T1-maps after contrast administration and dynamic acquisition. The resulting T1-fits have lower standard deviation and a higher signal-to-noise ratio which translates linearly to improved concentration curve estimation. Paul Wessel de Bruin1, Monique Reijnierse1, Matthias Jozef Petrus van Osch1 1Radiology Department, Leiden University Medical Center, Leiden, Netherlands A partial volume correction method for Dynamic Contrast-Enhanced MRI is presented that can correct for underestimation of first bolus passage in T1-weighted MRI. The method improves the robustness and precision of AIF measurement, even in very small ROIs, provided that the artery is oriented parallel to the main magnetic field. 1722. Improved T1 Mapping with Iterative Actual Flip-Angle Imaging (IAFI) Technique Yiqun Xue1, Mark A. Rosen1, Hee Kwon Song1 1Radiology, University of Pennsylvania, Philadelphia, PA, United States Actual flip angle imaging (AFI) technique was recently developed to estimate the true flip angle and has been used in conjunction with the variable flip angle (VFA) technique for improved T1 measurement accuracy. One of the limitations of AFI, however, is that the method assumes that T1 is much greater than the repetition time TR. When this assumption is violated, large errors can result in both the flip angle and T1 estimation. We propose an novel iterative AFI method which yields accurate T1 values without requiring that TR << T1. Sarayu Ramachandran1, Claudia Calcagno1, Zahi Fayad1 1Translational and Molecular Imaging Institute, Mount Sinai School of Medicine, New York, NY, United States This study covers the anisotropic diffusion filtering and phase-correlation based registration of dynamic contrast-enhanced magnetic resonance images of human carotid arteries 1724. Feasibility of Whole-Brain Dynamic Contrast Enhanced (DCE) MRI Using 3D K-T PCA Henrik Pedersen1, Adam Espe Hansen1, Sebastian Kozerke2, Henrik B.W. Larsson1 1Functional Imaging Unit (KFNA), Glostrup Hospital, Glostrup, Denmark; 2Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland Dynamic contrast-enhanced (DCE) MRI currently suffers from limited spatial coverage, preventing whole-brain quantification of cerebral blood flow. This study presents a new fast 3D imaging sequence for whole-brain DCE-MRI, which achieves a spatial coverage of 20 slices per second. The new sequence achieves faster imaging by skipping the saturation recovery (SR) pulses of conventional DCE-MRI and undersampling k-space using k-t PCA and partial Fourier imaging. The overall image quality of the proposed sequence is similar to conventional DCE-MRI, but we conclude that reliable sampling of the arterial input function requires a separate data acquisition, i.e., a dual-bolus approach. 1725. Stability of Quantitative CBF Measurements Using the T1-Based DCE Approach Otto Mųlby Henriksen1, Henrik B.W. Larsson1, Adam E. Hansen1,2, Egill Rostrup1 1Functional Imaging Unit, Dept. of Clinical Physiology and Nuclear Medicine, Glostrup Hospital, Glostrup, Denmark; 2Dept. of Radiology, Glostrup Hospital, Glostrup, Denmark Partial volume effect (PVE) may cause erroneous determination of the arterial input function (AIF) leading to inaccurate measurements of cerebral blood flow (CBF) in bolus tracking MRI. Analyzing dynamic contrast enhanced CBF measurements in healthy subjects, we studied the effect of different PVE correction methods on 1) agreement of CBF using AIF from either the right or the left internal carotid artery 2) repeatability of repeated measurements. Scaling of the AIF to the venous output function, either by least square fit or area under the concentration curves yielded better agreement and repeatability compared to cerebral blood volume correction methods. Matthew R. Orton1, David J. Collins1, Christina Messiou1, Elly Castellano1, Jean Tessier2, Shirley Spratt3, Martin O. Leach1 1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom; 2Early Clinical Development, AstraZeneca, Alderley Park, Macclesfield, United Kingdom; 3Clinical Discovery Team, AstraZeneca, Alderley Park, Macclesfield, United Kingdom The blood plasma curve shape is an important component of many modelling approaches for DCE imaging, and models of these curves are used to produce functional parameter estimates. For predictions or comparisons to be made using plasma curve data obtained with different injection lengths or profiles it is necessary to include the effect of the injection profile on the plasma curve. In this abstract we present a general methodology to estimate a vascular impulse response function which is independent of the injection profile, and can therefore be used to perform such predictions and comparisons. 1727. Comparison of Baseline Signal Correction Methods for Dynamic Contrast Enhanced MRI Yiqun Xue1, Mark A. Rosen1, Hee Kwon Song1 1Radiology, University of Pennsylvania, Philadelphia, PA, United States In DCE-MRI, perfusion parameters are particularly sensitive to the accuracy of the baseline (pre-contrast) signal of the AIF and tumor. However, the SNR of the pre-contrast data can be very low, particularly at high spatial resolutions since the T1 of blood and tissue are much longer than the TR. In this abstract, we compare three different baseline correction methods: magnitude averaging, Rician correction and complex averaging. It is shown that with sufficient amount of baseline data, measurement errors due to noise can be reduced most effectively by averaging of the complex data. Jehoon Yang1, Geun-Ho Im2, Jae-Hun Kim1, Hyejung Heo2, Sera Yoon2, Eunhee Cho2, Jaewon Lee2, Jung Hee Lee1 1Radiology, Sungkyunkwan University School of Medicine, Seoul, Korea, Republic of; 2Center for Molecualr and Cellular Imaging, Samsung Medical Center, Seoul, Korea, Republic of Converging evidences have indicated that dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) provides parameters indicating permeability of tumor microvessels which has been shown to be closely related to angiogenesis. Because endothelial cells are thought to be genetically stable compared with tumor cells, tumor vasculature can be one of promising target for novel anticancer agents. Therefore we designed this study to investigate the anti-angiogenic inhibitory effect of KR-31831 that was newly developed for anti-ischemic agent by our co-worker group on xenografted human ovarian carcinoma model using DCE-MRI on a micro 7.0 Tesla MR system. Our preliminary results suggest DEC-MRI may be useful tools to evaluate the anti-angiogenic effect of KR-31831 on xenografted human ovarian carcinoma model. 1729. Quantification of Blood-Brain Barrier Permeability in the Mouse Brain in Vivo Sang-Pil Lee1,2, Jieun Kim1, Nancy Berman3 1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States; 2Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, United States; 3Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, United States Measuring blood-brain barrier (BBB) permeability in mice has been challenging because estimation of vascular contrast agent concentrations in the blood is especially difficulty due to the requirement of very high spatial resolution. We have overcome the difficulty by combining pre-contrast T1 mapping and high-resolution spin-echo T1-weighted imaging. We have successfully quantified BBB permeability in vivo from the signal changes associated with uptake of Gd-DTPA following traumatic brain injury using the Patlak plot technique. Results show that significant entry of Gd into the brain was evident in the injury site with excellent linear relationship between tissue concentration of Gd and the stretched time. 1730. Blood-Brain Barrier Permeability Measured by DCE MRI Predicts Perihematomal Edema Diffusivity Didem Bilensoy Aksoy1, Roland Bammer2, Michael Mlynash1, Sandeep N. Gupta3, Ryan W. Snider1, Irina Eyngorn1, Chitra Venkatasubramanian1, Nancy Fischbein2, Christine A.C. Wijman1 1Department of Neurology and Neurological Sciences, Stanford Stroke Center, Stanford University, Palo Alto, CA, United States; 2Department of Radiology, Stanford University, Palo Alto, CA, United States; 3Global Research Center, General Electric, Niskayuna, NY, United States Dynamic Contrast-Enhanced (DCE) MRI was used as a tool to assess and quantify blood-brain barrier (BBB) injury following spontaneous intracerebral hemorrhage (ICH). BBB permeability and its relationship with perihematomal tissue diffusivity, a sign of edema severity, were studied. Significantly increased BBB permeability in the region immediately surrounding the hematoma was observed. BBB leakage correlated with diffusivity in the region surrounding the hematoma. Hilde Kjeldstad Berg1, Paal Erik Goa2, Olav Haraldseth3, Henrik B W Larsson4 1HiST, Sor-Trondelag University College, Trondheim, Norway; 2Department of Diagnostic Imaging, St Olavs Hospital, Trondheim, Norway; 3Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 4Functional Imaging Unit, Glostrup Hospital, University of Copenhagen, Glostrup, Denmark The purpose of this study was to further develop and validate a new method for quantitative cerebral perfusion measurements, using dynamic contrast enhanced T1-weighted MR imaging. Healthy volunteers were examined in rest and during visual stimulation. Visual stimulation resulted in a significant increase in cerebral blood flow (CBF) in the occipital region, and the increase was in accordance with literature values. In other areas of the brain, CBF remained unchanged. Cerebral blood volume was also measured, but the increase observed was not found to be significant. Su-Chin Chiu1,2, Chun-Juan Juan2, Hsiao-Wen Chung1,2, Cheng-Chieh Cheng1,2, Hing-Chiu Chang, 1,3, Hui-Chu Chiu4,5, Cheng-Hsien Hsu2,6, Cheng-Yu Chen2, Guo-Shu Huang2 1Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; 2Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan; 3Applied Science Laboratory, GE Healthcare, Taipei, China; 4Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan; 5EMBA in Global Chinese Management, Tamkang University, Taiwan; 6Quanta Computer Inc., Taipei The effects of fat saturation on quantitative perfusion measurements using dynamic contrast-enhanced (DCE) MRI have not been documented for the parotid glands. In this study we included phantom and in vivo studies to compare the relationship between fat content and the difference between perfusion parameters derived from non-fat-saturated (NFS) and fat-saturated (FS) DCE-MRI. Significant differences were found for all amplitude-related parameters in parotid glands but not for muscular tissue. It is suggested that the use of FS or NFS should be explicitly specified for objective comparison of perfusion parameters with DCE-MRI on fat-containing tissues such as the parotid glands.
Richard Leigh1, Argye Elizabeth Hillis2, Peter B. Barker3 1Neurology, Johns Hopkins Univeristy School of Medicine, Towson, MD, United States; 2Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 3Radiology, Johns Hopkins Univeristy School of Medicine, Baltimore, MD, United States Detection of permeability derangements in stroke patients may help guide therapy and improve outcomes. PWI, which is routinely performed in stroke imaging, can be used to assess permeability derangements through accumulation of contrast into the brain parenchyma. However it is unclear how the recorded signal can be quantified and normalized across patients. We analyzed nine stroke patients with evidence of contrast leakage on PWI to see how differences in acquisition parameters affected the recorded signal. We found that the measurements were greatly affected not only by the acquisition parameters but also the tissue type from which the signal was recorded. Yanming Yu1,2, Jun Li1, Quan Jiang3, Shanglian Bao1, Yi Zhong4, Yongquan Ye2, Jiong Zhu5, Yongming Dai6, Ewart Mark Haacke2, Jiani Hu2 1Beijing key lab of medical physics and engineering, Peking University, Beijing, China; 2Department of Radiology, Wayne State University, Detroit, MI, United States; 3Department of Neurology, Henry Ford Health Sciences Center, Detroit, MI, United States; 44. Sino-Dutch Biomedical & Information Engineering, Northeastern University, Shenyang, Liaoning, China; 5Department of Radiology, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai; 6Healthcare, Magnetic Resonance Imaging, Siemens Ltd. China, Shenzhen, Guangdong, China There are several practical limitations in quantitative analysis of clinical DCE-MRI for assessing treatment response, including: 1) difficulty in obtaining an accurate arterial input function (AIF); 2) the long scanning time to accurately estimate baseline T1(0); and 3) often highly variable or unphysical results due to noise effects; 4) long computational time. We develop a method that combines a fixed-T1, the Fuzzy C-Means and the reference region model to overcome the aforementioned limitations in quantitative analysis of clinical DCE-MRI without measuring either an AIF or T1(0), and demonstrate its feasibility to assess neoadjuvant chemotherapy for breast cancer using clinical DCE-MRI. Benjamin Lemasson1,2, Raphaėl Serduc3, Cecile Maisin1,4, Audrey Bouchet3, Nicolas Coquery1,4, Philippe Robert5, Christopoh Segebarth1,4, Géraldine Le Duc3, Irčne Tropres1,4, Chantal Rémy1,4, Emmanuel Louis Barbier1,4 1Inersm U836, Grenoble, France; 2Oncodesign Biotechnology, Dijon, France; 3ESRF, Grenoble, France; 4Université Joseph Fourier, Grenoble Institut des Neurosciences, Grenoble, France; 5Guerbet Research, Aulnay-Sous-Bois, France Numerous anti-tumor therapies modify the permeability (increase or decrease) of tumoral or healthy vessels. Permeability can be assessed by Dynamic Contrast-Enhanced-MRI (DCE-MRI). Low- (0.5kDa) and macro (3.5kDa) -molecular-weight-CM, DCE-MRI was performed within the same imaging session on 80 rats bearing 9L gliosarcoma before and three times after treatments onset (antiangiogenic and/or synchrotron radiotherapy), searching for possible increase or decrease in vessel wall permeability. This study suggests that the choice of CM for a DCE-MRI depends on the physiological questions to be addressed. It also suggests that the use of two CM within the same MRI session is feasible. Arterial Spin Labeling Hall B Thursday 13:30-15:30 1736. Model of Blood Transport Couples Delay and Dispersion and Predicts ASL Bolus Measurements Peter Gall1, Matthias Guether2,3, Valerij Kiselev1 1Medical Physics, University Hospital Freiburg, Freiburg, Germany; 2Fraunhofer MEVIS, Institute for Medical Image Computing, Bremen; 3Faculty for Physics and Electrical Engineering, University Bremen, Bremen, Germany The properties of the blood transport through the brain vasculature is of fundamental interest for the diagnosis of cerebral diseases and therefore of particular interest for the associated imaging modalities in MRI such as DSC perfusion or ASL. In this work a model for a vascular tree together with laws of laminar flow are used to describe the blood transport through early branches of the vascular tree. This description is in excellent agreement with data measured using ASL. 1737. Asymmetric FAIR - FAIR with Active Suppression of Superior Tagging (FAIR ASST) Xiufeng Li1, Subhendra N. Sarkar2, David E. Purdy3, Robert W. Haley4, Richard W. Briggs1,4 1Radiology, UT Southwestern Medical Center, Dallas, TX, United States; 2Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 3Siemens Healthcare, Malvern, PA, United States; 4Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States The superior labeling band of FAIR can also label blood, which results in adverse venous artifacts and an inconsistency between the single subtraction blood flow quantification model and the experimental data. To overcome the difficulties faced by the traditional FAIR-based PASL technique, an asymmetric FAIR - FAIR with Active Suppression of Superior Tagging (FAIR ASST) - was proposed and evaluated. Among various possible ways for the suppression of FAIRs superior tagging, the method using one pre-inversion and two post-inversion superior saturations was found to be effective and efficient. Guillaume Duhamel1, Virginie Callot1, Patrick J. Cozzone1, Frank Kober1 1CRMBM / CNRS 6612, Faculté de Médecine, Université de la Méditerranée, Marseille, France A new strategy for continuous arterial spin labeling using pulsed RF and gradient fields (pCASL) has recently been developed for human studies, showing SNR advantages. pCASL should be in principle also a method of choice for small animal studies. However, its feasibility as well as its SNR advantages over pulsed ASL techniques at very high field remains to be demonstrated. In particular, the labeling efficiency is expected to be challenged by short blood T2 values and hardware constraints. This work presents a practical investigation of pCASL implementation and feasibility at very high field (11.75T) for mouse brain perfusion studies. Youngkyoo Jung1, Thomas T. Liu1 1Radiology, Univerisity of California, San Diego, La Jolla, CA, United States The multi-phase pseudo-continuous arterial spin labeling (MP-PCASL) method offers more robust cerebral blood flow (CBF) quantification than the conventional PCASL method and higher SNR than Pulsed ASL. However, the MP-PCASL method requires a per-voxel fit to the nonlinear signal equation. This time required for this nonlinear fitting procedure (about 5 minutes) can be problematic for applications such as optimized PCASL for functional MRI studies. Here we propose a signal demodulation processing method for MP-PCASL that utilizes the dominant sinusoidal component at the multi-phase frequency. We show the proposed demodulation method can provide reliable CBF estimates while providing faster estimation time. Cheng Ouyang1, Bradley P. Sutton1,2 1Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 2Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States Transfer Insensitive Labeling Technique (TILT) has been used to measure cerebral blood flow as a pulsed arterial spin labeling (PASL) method. With the MT-insensitive feature, we propose to convert the original TILT to be further developed into a novel non-flow-driven pulsed-continuous ASL technique, named pulsed-continuous TILT (pTILT), with higher signal and fewer artifacts. Simulation show comparable labeling efficiency of pTILT compared to the current pulsed-continuous flow-driven adiabatic labeling techniques. In vivo human perfusion measurements by pTILT agree with literature S. L. Talagala1, W-M Luh2, H. Merkle3 1NMRF, NINDS, National Institutes of Health, Bethesda, MD, United States; 2FMRIF, NIMH, National Institutes of Health, Bethesda, MD, United States; 3LFMI, NINDS, National Institutes of Health, Bethesda, MD, United States Currently, CASL perfusion studies are performed using constant amplitude labeling pulses to match the average blood velocity over the cardiac cycle. This can lead to lower inversion efficiency during the high flow velocity periods. Use of higher constant labeling RF amplitudes increase the power deposition and also can reduce the inversion efficiency for lower velocities. In this work we show that real-time change in labeling RF power according velocity may be used to reduce power deposition from the labeling pulse without loss in perfusion sensitivity. This method should be especially useful for CASL at 7T and higher fields. 1742. Reduced Specific Absorption Rate (SAR) Pseudo-Continuous Arterial Spin Labeling Hesamoddin Jahanian1,2, Douglas C. Noll1,2, Luis Hernandez-Garcia1,2 1Functional MRI Laboratory, University of Michigan, Ann Arbor, MI, United States; 2Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States A reduced specific absorption rate (SAR) version of Pseudo-continuous arterial spin labeling (pCASL) pulse sequence is designed and implemented. Using a simulation study a set of pCASL pulse sequence parameters is found that allows reducing the flip angle of pCASL RF pulses (i.e. reducing SAR) without losing the inversion efficiency. The proposed set of parameters employs smaller slice selective gradients which leads to less acoustic noise. This makes it more desirable especially for functional MRI studies. 1743. Improved ASL Contrast in Multiphase STAR Labeling F. F. Paiva1, B. U. Foerster2, F. Tovar-Moll1, J. Moll1 1DOr Institute for Research and Education, Rio de Janeiro, RJ, Brazil; 22Philips Medical Systems, LatAm, Sao Paulo, Brazil Multiphase ASL is an effective way to overcome the regional variation of the transit time that difficult the estimation of perfusion values. However, with conventional multiple phases ASL techniques, the ASL contrast at later phases is impaired due to repeated application of excitation pulses and longitudinal relaxation making it difficult to evaluate the tissue perfusion in regions where the transit time is longer. In the present study, we present an improvement of the acquisition scheme by exploring a modulation on the flip angle of the MR acquisition to keep the ASL contrast constant over multiple phases. David D. Shin1, Youngkyoo Jung1, Ajit Shankaranarayanan2, Khaled Restom1, Jia Guo1, Wen-Ming Luh3, Peter Bandettini3, Eric C. Wong1, Thomas T. Liu1 1University of California, San Diego, CA, United States; 2GE Healthcare, Waukesha, WI, United States; 3National Institute of Health, Bethesda, MD, United States The optimized pseudo-continuous arterial spin labeling (Opt-PCASL) is a variant of the PCASL method that provides higher tagging efficiency through estimation and correction of phase errors. The original implementation required extensive user-intervention, including subjective definition of vascular territories and manual input of scan parameters. A new automated optimization procedure incorporates vascular territory imaging for objective measure of vessel territory maps and a scan process that requires minimal user intervention. In three healthy subjects, the phase errors were reduced below 15° after one calibration step. The approach is expected to facilitate the use of the Opt-PCASL technique for quantitative fMRI studies. 1745. Improved ASL Imaging with 3D GRASE PROPELLER Huan Tan1, W. Scott Hoge2, Craig A. Hamilton1, Robert A. Kraft1 1Virgina-Tech Wake Forest School of Biomedical Engineering, Winston-Salem, NC, United States; 2Radiology, Brigham and Women's Hosptial, Boston, MA, United States 3D GRASE offers an inherent SNR advantage for ASL perfusion imaging over conventional 2D EPI. However, it suffers from through-plane blurring due to T2 decay that reduces image quality and limits spatial resolution. Incorporating a PROPELLER trajectory into 3D GRASE reduces the ETL and subsequently the through-plane blurring. Furthermore, a PROPELLER trajectory is less susceptible to field inhomogeneities due to its shorter echo train length. In summary, 3D GRASE PROPELLER improves ASL perfusion images without increasing scan time while maintaining the perfusion SNR. 1746. Improving the Spatial Resolution of 3D GRASE ASL Emma Louise Hall1, Penny A. Gowland1, Susan T. Francis1 1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom 3D-GRASE has been used with ASL but generally at coarse in-plane resolution to reduce off-resonance phase errors, and limited slice resolution to reduce through slice decay and blurring. Here we assess the use of parallel imaging combined with multi-shot acquisition and outer volume suppression (OVS) to reduce the inter-RF spacing in 3D-GRASE, allowing the acquisition of 3D-GRASE ASL data with improved spatial resolution at 3T. OVS 3D-GRASE is applied to a functional paradigm to study visual activity. 1747. Optimising Image Readout for Perfusion Imaging at 7T Emma Louise Hall1, Penny A. Gowland1, Susan T. Francis1 1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom Echo Planar Imaging (EPI) is commonly used in conjunction with arterial spin labelling (ASL) due to short image acquisition times. However EP images are affected by susceptibility artifacts and chemical shift artifacts, particularly at increased field strength. Here the use of True-FISP and FLASH acquisitions are compared to EPI based ASL measurements at 7T, signal-to-noise ratio and coefficient of variation are assessed for each acquisition method. Non-EP methods are shown to be advantageous at high in-plane resolution (1 mm), with True-FISP providing the best SNR, however slice coverage is limited due to SAR at 7T. 1748. Benefits of Interleaved Continuous Labeling and Background Suppression Weiying Dai1, Philip M. Robson1, Ajit Shankaranarayanan2, David C. Alsop1 1Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 2Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States CContinuous arterial spin labeling (CASL) can produce greater signal and reduced dependence on arterial transit timing than pulsed ASL. These benefits of CASL are reduced, however, when the labeling duration is shortened for compatibility with background suppression. In theory, continuous labeling can be performed interleaved within the background suppression sequence as long as the labeling/control are modulated correctly. Here we compare the performance of interleaved labeling with a more traditional background suppression approach and demonstrate the increased signal achievable with the longer labeling made possible by interleaving with the background suppression. 1749. Improving CBF MRI Using a Background Suppression in CASL with a Separate Labeling Coil Qiang Shen1, Gang Zhu2, Timothy Q. Duong1 1Research Imaging Institute, Ophthalmology/Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States; 2Bruker BioSpin Corporation, Billerica, MA, United States Reduction or elimination of the static tissue signal in an arterial spin labeling (ASL) study could improve sensitivity and reproducibility. Such static tissue signal reduction has been achieved with the use of additional inversion pulses after the labeling of arterial spins in single-coil ASL techniques. This work further developed quantitative multislice CBF acquisition for the inversion recovery continuous ASL technique with a separate labeling coil that we proposed previously in rats. We further applied this approach to image focal ischemia in rats. The current IR-cASL scheme offers some unique advantages for rodent studies where the arterial transit time is short. 1750. Towards an Optimal Distribution of B-Values for IVIM Imaging Andreas Lemke1, Frederik Bernd Laun2, Lothar Rudi Schad1, Bram Stieltjes3 1Deparmtent of Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 3Deparmtent of Radiology, German Cancer Research Center, Heidelberg, Germany The b-value distribution for IVIM imaging was optimized using Monte Carlo simulations in order to minimize the uncertainty of the biexponential fit. For three different parameter settings, illustrating the IVIM parameters in brain, liver and kidney, the error of the calculated optimal b-value distribution was compared with the error of previously reported distributions. The error for this optimized distribution was significantly lower for all parameter settings when compared with currently used distributions. The results demonstrate that the presented choice of b-values can substantially minimize the overall measurement error in IVIM and may aid the choice of b-values in clinical experiments. 1751. Test-Retest Reproducibility of Perfusion Measurements Using PASL at 3 T Christine Preibisch1, Annette Förschler1, Afra Wohlschläger1, Christian Sorg2, Alexander Kurz2, Claus Zimmer1, Panagiotis Alexopoulos2 1Abteilung für Neuroradiologie, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany; 2Klinik und Poliklinik für Psychiatrie und Psychotherapie, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany Problem: The aim of the current study was to investigate the reproducibility of PASL imaging based on the PULSAR technique combined with thin slice periodic saturation (Q2TIPS) to control for bolus length and facilitate CBF quantification. Methods: Resting CBF maps were obtained from 16 subjects (30±10a) on two different days on a 3T whole body scanner. Results: Mean CBF, within-subject standard deviation and repeatability were 34.1±5.3, 3.5 and 9.7 in GM and 7.4±2.7, 2.7and 7.5 in WM (all values in ml/100g/min). Conclusion: PULSAR based perfusion measurement shows good reproducibility lying in the range detected for other ASL methods. John Robert Cain1, Gerard Thompson1, Alan Jackson1, Laura M. Parkes1,2 1Imaging Science, University of Manchester, Manchester, United Kingdom; 2Biomedical Imaging Institute, University of Manchester, Manchester, United Kingdom Groups have published reproducibility studies for arterial spin labeling (ASL) cerebral blood flow (CBF) measurements. The relatively large inter-subject variation in CBF hinders direct comparison between individuals. A single healthy volunteer underwent MRI imaging on 7 separate occasions consisting of two STAR ASL acquisitions. Intra-session reproducibility was assessed using Bland-Altman analysis of grey matter perfusion and arrival time. Inter-session and intra-session perfusion values coefficient of variation (COV) were comparable, suggesting errors due to re-positioning and physiological changes are not significant. The COV of perfusion values are consistent with published results using multiple individuals and the arrival time COV is superior. 1753. Inter- And Intra-Subject Variability of CBF Measurements Using PCASL Method Tie-Qiang Li1, Tomas Jonsson1, Maria Kristoffersen Wiberg2, Jiongjiong Wang3 1Department of Medical Physics, Karolinska University Hospital, S-141 86, Stockholm, Sweden; 2Department of Radiology, Karolinska University Hospital, S-141 86, Stockholm, Sweden; 3Department of Radiology, University of Pennsylvania, United States PCASL techniques have become very attractive for pharmacokinetics studies and clinical applications where repetitive, longitudinal, and quantitative CBF measurements are desirable. One important issue need to addressed is the inter- and intra-subject variability of the measured CBF results. In this study, we experimentally investigated this issue using an optimized PCASL protocol at 3T. The results indicate that the inter-subject variability is about 2-3 time of that for intra-subject depending the chosen ROI size (from voxel to whole brain). 1754. Maximizing Statistical Power of ASL MRI in Detecting Regional CBF Differences Sina Aslan1, Hanzhang Lu1 1AIRC, UT Southwestern Medical Center, Dallas, TX, United States We conducted numerical simulations and experimental measurements to see how sensitive is ASL MRI in detecting regional activity difference between patients and controls and what is the best strategy to detect such a difference. We used a model condition in which we simulated a patient group by having the subject view a flashing checkerboard and compared their CBF to that of a control group of subjects viewing a fixation. Our results suggest that, when it comes to detect regional CBF differences between two subject groups, rCBF is a more sensitive marker. 1755. White Matter Cerebral Blood Flow Detection Using Arterial Spin Labelling Nyssa Elaine Craig1, Dinesh Selvarajah2, Esben Thade Petersen3, Xavier Golay4, Solomon Tesfaye5, Paul Griffiths1, Iain David Wilkinson1 1Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom; 2Diabetes Unit, University of Sheffield, Sheffield, South Yorkshire; 3Center for Functionally Integrative Neuroscience, Aarhus University Hospital, Denmark; 4Centre for Neuroimaging Techniques, University College London, London, United Kingdom; 5Diabetes Unit, University of Sheffield, Sheffield, South Yorkshire, United Kingdom The sensitivity of the Arterial Spin Labelling technique to detect Cerebral Blood Flow (CBF) within the white matter of the brain has been under dispute for some time. The present study poses a vasodilatory challenge to thirteen normal, healthy control subjects using Acetazolamide, and uses the QUASAR sequence to assess CBF both pre- and post-administration. The results show a high contrast to noise ratio, with a statistically significant increase in mean white matter perfusion across all subjects, indicating that the effect can be detected in this tissue type, despite lower absolute flow values than those detected in grey matter. 1756. Hippocampus Perfusion Studies Using OPTIMAL FAIR Xiufeng Li1, Subhendra N. Sarkar2, David E. Purdy3, Robert W. Haley4, Richard W. Briggs1,4 1Radiology, UT Southwestern Medical Center, Dallas, TX, United States; 2Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 3Siemens Healthcare, Malvern, PA, United States; 4Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States To facilitate reliable and sensitive perfusion measurements in the sub-regions of the hippocampus, we developed OPTIMAL FAIR (orthogonally positioned imaging tagging method for arterial labeling with FAIR) and performed comprehensive optimization studies for the proper selection of arterial spin labeling parameters. Study results indicated that the anterior segment of the hippocampus has different blood flow dynamic characteristics from the other parts of the hippocampus, e.g. the lowest perfusion and the longest transit time, which can be due to different sources of arterial blood supply. 1757. Regional Cerebral Blood Flow Changes of a SIV-Infected Monkey Model of Neuro-AIDS Chun-xia Li1, Xiaodong Zhang1, Amelia Komery2, Francis J. Novembre2, James G. Herndon3 1Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA,30329, United States; 2Divisions of Microbiology and Immunology, Yerkes National Primate Research Center, Emory University, Atlanta, GA,30322; 3Divisions of Neuroscience, Yerkes National Primate Research Center, Emory University, Atlanta, GA,30322 The regional cerebral blood flow (rCBF) measure has been proposed as a biomarker for HIV-associated CNS damage. In this study we used the continuous arterial spin labeled (CASL) MRI technique to quantitatively measure the longitudinal pattern of rCBF change in the selected ROIs of Simian Immunovirus Virus (SIV)-infected monkey model following infection. The finding indicates rCBF in selected ROIs declined after the SIV inoculation resembling with the HIV+ patient, and the rCBF changes correlated well with the depletion of CD4, which suggests CASL may be a surrogate biomarker for accessing the progression of the disease and treatment development. 1758. Simultaneous CBF and BOLD Mapping of Electrical Acupoint Stimulation Induced Brain Activity Yue Zhang1, Christopher B. Glielmi, Yin Jiang2, Jing Liu3, Ying Hao4, Xiaoying Wang3,4, Jing Fang, 1,4, Jisheng Han2, Jue Zhang, 1,4, Xiaoping Hu5 1College of Engineering, Peking University, Beijing, China; 2Neuroscience Research Institute, Peking University, Beijing, China; 3Dept.of Radiology, Peking University First Hospital, Beijing, China; 4Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; 5Dept. of Biomedical Engineering, Georgia Institute of Technology / Emory University, Atlanta, United States Blood oxygenation level dependent (BOLD) technique has been used to map brain activity related to electrical acupoint stimulation (EAS) in previous pain-relief studies, but introduces relatively poor reproducibility and consistencies. In this study, the dual-echo based simultaneous acquisition of cerebral blood flow (CBF) and BOLD was employed to provide the first evidence of CBF response to EAS and inter-subjects”Æ variation was compared between the two techniques. The results suggested that the sensitivity and specificity to sensory and pain-related regions were consistent with previous findings. Moreover, CBF based inter-subjects”Ævariation had a significant decrease than BOLD. Jeff D. Winter1, Jackie Leung1, Manohar Shroff2,3, Andrea Kassner1,3 1Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; 3Medical Imaging, University of Toronto, Toronto, Ontario, Canada Cerebrovascular reactivity (CVR) measures of the cerebral blood flow (CBF) response to CO2 may benefit clinical assessment of cerebrovascular disease. CVR imaging is typically performed using indirect BOLD signal changes or arterial spin labeling (ASL) CBF measures. In this study, we compared between-day reproducibility of BOLD and ASL (Look-Locker acquisition) CVR measures performed with controlled CO2 transitions in adults. Reproducibility was quantified with the between-day coefficient of variation (CV). Reproducibility of ASL-CVR measures of CBF the response to CO2 (CV < 17%) were similar to BOLD-CVR (CV < 19%), which points to the potential clinical utility of this method. Andre Marquand1, Sara De Simoni, Owen O'Daly, Fernando Zelaya, Mitul Mehta 1Centre for Neuroimaging Sciences, Institute of Psychiatry, London, United Kingdom Methylphenidate and atomoxetine are widely used for the treatment of attention-deficit/hyperactivity disorder, but their differential effects on human brain physiology are poorly understood. We apply a multivariate pattern recognition algorithm (Gaussian process classification) to continuous arterial spin labelling data recorded while subjects were at rest which accurately discriminates methylphenidate from atomoxetine and each drug from placebo. We show a distributed network of brain regions underlies discrimination, with differential effects in putamen, anterior cingulate and temporal poles. Multivariate pattern recognition may be a useful technique for detection of diffuse pharmacological effects. 1761. Does Pulsed Arterial Spin-Labeling Selectively Underestimate Responses to Global Challenges? Felipe B. Tancredi1,2, Claudine J. Gauthier, 2,3, Cécile J. Madjar2, Richard D. Hoge1,2 1Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada; 2UNF, CRIUGM, Montreal, Quebec, Canada; 3Physiology, Université de Montréal, Montreal, Quebec, Canada ASL is a technique of particular interest for studies in which hypercapnia challenge is employed. We sought to test whether the shortening in blood transit time that vasodilation by moderate hypercapnia may cause was leading to a systematic underestimation of perfusion responses measured with ASL. We measured flow responses in three different moments: at hypercapnia, during visual stimulus and when both were simultaneously present. We found that the response to the combined stimulus was a linear combination of the responses the individual stimulus alone, thats to say, the focal response to a visual stimulus during hypercapnia challenge was not underestimated. ASL is a technique of particular interest for studies in which hypercapnia challenge is employed. We sought to test whether the shortening in blood transit time that vasodilation by moderate hypercapnia may cause was leading to a systematic underestimation of perfusion responses measured with ASL. We measured flow responses in three different moments: at hypercapnia, during visual stimulus and when both were simultaneously present. We found that the response to the combined stimulus was a linear combination of the responses the individual stimulus alone, thats to say, the focal response to a visual stimulus during hypercapnia challenge was not underestimated. Yuguang Meng1, Seong-Gi Kim1,2 1Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States; 2Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, United States The blood transit time from arterial spin labeling plane to capillaries in the imaging slice (referred to as tissue transit time) decreased during neuronal activation in humans, while it appeared no changes during somatosensory stimulation in rats. Since a tissue transit time is shorter in rats compared to humans, shortening blood transit time may not be detectable with arterial spin labeling (ASL) data with low temporal resolution. Thus, it is important to carefully measure dynamic transit time changes during stimulation. In this work, the dynamics of both CBF and the blood transit time during rat forepaw stimulation were simultaneously measured with a modified dynamic ASL (DASL) method with improved temporal resolution. 1763. ASL Based PhMRI in Assessing Serotonergic Response in Users of XTC Marieke L. Schouw1, Sanna Gevers1, Charles B.L.M. Majoie2, Jan Booij3, Aart J. Nederveen, Liesbeth Reneman 1Radiology, AMC, Amsterdam, Noord-Holland, Netherlands; 2Radiology, AMC, Amsterdam, Netherlands; 3Nuclear Medecine, AMC, Amsterdam We investigate whether pharmacologic magnetic resonance imaging (phMRI) is suitable in detecting serotonin terminal loss in users of XTC (MDMA, ecstasy). 10 XTC users and 7 controls underwent ASL (arterial spin labelling) based phMR imaging with a challenge with the selective serotonin reuptake inhibitor (SSRI) citalopram. Data were combined with single photon emission computed tomography (SPECT) imaging with [123I]ā-CIT. Markedly different citalopram-induced CBF changes were observed in XTC users compared to controls, in brain regions that also showed (a tendency) towards reduced SERT densities. These preliminary results suggest that ASL-based CBF measurements may be indirect measures of serotonin terminal loss. Arterial Spin Labeling: Beyond CBF Hall B Monday 14:00-16:00 Ying Sun1, Bing Wu2, Hua Zhong3, Xiaoying Wang2, Jue Zhang1,3, Jing Fang1,3 1College of Engineering, Peking University, Beijing, China; 2Dept. of Radiology, Peking University First Hospital, Beijing, China; 3Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China With the increase of cases of intracranial stenosis, the research to study the shortcut pathways caused by carotid artery stenosis manifested by abnormal external carotid artery perfusion image become very critical. In this preliminary study, an upgraded tagging strategy for Vessel Encoded Arterial Spin Labeling (VEASL) was employed to non-invasively evaluate the intra and extracranial carotid artery supplied cerebral perfusion of healthy volunteers, by tagging the right and left internal carotid arteries, the external carotid artery and the vertebral arteries. Results suggested that the proposed approach could separate the intracranial and extracranial parts of perfusion come from external carotid artery. Hironori Kamano1, Takashi Yoshiura1, Ivan Zimine2, Akio Hiwatashi1, Koji Yamashita1, Yukihisa Takayama1, Eiki Nagao1, Hiroshi Honda1 1Department of Clinical Radiology, Kyushu University, Fukuoka, Japan; 2Philips Electronics Japan Use of shared rotating control acquisition has been reported to substantially shorten total acquisition time in territorial ASL, while it may result in inaccurate estimate of “M from each feeding vessels due to incomplete compensation of magnetization transfer effects. In order to validate this technique in actual clinical interpretation, we performed an observer test. Results indicated an excellent over all agreement between the shared rotating control and normal control acquisitions. There was a tendency that, in the shared rotating control method, the territorial information may be less reliable in the territories of the posterior cerebral artery. 1766. Combined Assessment of Vascular Territories and Haemodynamic Parameter Maps Rebecca Susan Dewey1,2, Dorothee P. Auer1, Susan T. Francis2 1Division of Academic Radiology, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom Watershed areas are brain regions supplied by the most distal branches of the cerebral arteries and are most susceptible to haemodynamic ischaemia. We assess the use of territorial ASL to define Left and Right Internal Carotid, Anterior Cerebral, and Basilar Artery territories to distinguish the watershed area, and assess its correspondence with haemodynamic parameters (perfusion rate, arterial blood volume and arterial and tissue transit times) from multiphase ASL. Specified anatomical regions are assessed for vascular supply and haemodynamic parameters. Combining these techniques, an atlas of parameters can be formed for region-specific perfusion and position and functional effects of watershed areas. Keith S. St. Lawrence1,2, Jodi Miller1, Jiongjiong Wang3 1Imaging, Lawson Health Research Institute, London, ON, Canada; 2Medical Biophysics, University of Western Ontario, London, ON, Canada; 3Radiology, University of Pennsylvania, Philadelphia, PA, United States The arterial transit time (τa) and the exchange rate of water (kw) across the blood-brain barrier were determined using diffusion-weighted arterial spin labelling (ASL) with multiple post-labelling delay times. τa was determined using bipolar gradients to suppress the arterial signal (i.e., the FEAST method) and kw was determined using bipolar gradients strong enough to suppress all vascular signals and a kinetic model to characterize water exchange across the BBB. Averaged over four volunteers, kw was 119 min-1 in grey matter and τa was 1.26 s. From repeat measurements, the intra-subject coefficient of variation of kw was 12%. 1768. Flow-Weighted Arterial Transit Time Mapping of the Human Brain Toralf Mildner1, Stefan Hetzer1, Wolfgang Driesel1, Karsten Müller1, Harald E. Möller1 1NMR unit, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Saxony, Germany Mapping of Arterial Transit times by Intravascular Signal SElection (MATISSE) was performed with and without a mild flow-weighting (FW). The arterial transit times, δa, of the flow-weighted data were increased on average by about 700 ms and the signal amplitudes roughly were halved. Flow-through signals, i. e. signals of arterial vessels permeating the voxel, are removed almost completely, although the MATISSE signal still is expected to be of vascular origin. The fact that δa with mild FW was found to be easily larger than 2 s might be important for the quantification of CBF in standard dual-coil CASL experiments. Kun Lu1, Thomas T. Liu1, Youngkyoo Jung1 1Center for Functional MRI, UCSD, La Jolla, CA, United States Conventional arterial transit delay measurements consist of a series of separate ASL experiments acquired at several different post-labeling delays. Such measurements are usually time-consuming and can be formidable overheads for ASL studies. The time requirement also makes the measurements highly sensitive to motion. This study presents a simple yet effective modification of the conventional method for measuring transit delay with shorter scan time and less motion sensitivity. Such a method could be beneficial to all ASL studies. Weiying Dai1, Philip M. Robson1, Ajit Shankaranarayanan2, David C. Alsop1 1Radiology, Beth Israel Deaconess Medical Center,Harvard Medical School, Boston, MA, United States; 2Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States Conventional ASL perfusion quantification requires division by a proton density reference image and assumes a uniform brain-blood partition coefficient. The brain-blood partition coefficient is not constant, however, and may especially differ in areas of pathology. In cortical regions where CSF, white matter and gray matter may all be mixed within a voxel, division by the proton density image can also add nonlinear systematic errors. Here we propose using an optimized inversion preparation to generate an image whose intensity is essentially independent of tissue type. This highly homogeneous image can replace the proton density image and makes the assumption of a brain-blood partition coefficient unnecessary. In-vivo results demonstrate that such homogeneous contrast is achievable and can be used to improve the pixel-by-pixel perfusion measurement. 1771. Potential Tracking of Oxygen Consumption Using Arterial Spin Labeling Susceptibility Imaging Johannes Gregori1,2, Norbert Schuff3,4, Matthias Günther1,5 1Institute for Medical Image Computing, Fraunhofer MEVIS, Bremen, Germany; 2Neurology, Universitätsmedizin Mannheim, Heidelberg University, Mannheim, Germany; 3Radiology & Biomedical Imaging, University of San Francisco, San Francisco, CA, United States; 4Center for Imaging of Neurodegenerate Diseases (CIND), VA Medical Center, San Francisco, CA, United States; 5mediri GmbH, Heidelberg, Germany We present ASL time series measurements with spin/gradient double echo spiral 3D-GRASE readout to quantify R2' of the ASL difference signal. R2' can give information about blood oxygenation and blood volume, while ASL time series are used to investigate perfusion dynamics. Using the combination of both techniques, we can measure the changes of R2' over different inflow times and discuss the physiological underlyings. 1772. Improving the Stability of T2 Measurements in ASL Experiments Johanna Kramme1,2, Johannes Gregori1,2, Matthias Günther2,3 1Division of Neurology, University Hospital Mannheim of the University of Heidelberg, Mannheim, Germany; 2Fraunhofer MEVIS-Institute for Medical Image Computing, Bremen, Germany; 3Faculty for Physics and Electrical Engineering, University Bremen, Bremen, Germany To increase sensitivity and reduce physiological noise in ASL T2 measurements a single shot 3D-GRASE approach was developed. Compared to sequential acquisition of the different echo times significant reduction in scan time and physiological noise can be achieved. To improve T2 calculations the inflow time TI of each data set has to be corrected for each echo time. Based on the TE correction of TI the reliability of the T2 estimate could be improved by a factor of two and more. With these improvements ASL T2 measurements become feasible in a clinical stetting. Lirong Yan1, Yan Zhuo1, Jing An2, Jiongjiong Wang3 1Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; 2Siemens Mindit Magnetic Resonance, Siemens Healthcare, MR Collaboration NE Asia, Shenzhen, China; 3Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States In the present study, we present a novel technique termed TrueFISP based Spin Tagging with Alternating Radiofrequency (TrueSTAR) for both time-resolved 4-D MR angiography (MRA) and dynamic microvascular flow (perfusion) imaging. We demonstrate that TrueSTAR is able to delineate the dynamic filling of cerebrovasculature with a spatial resolution of 1x1x1mm3 and a temporal resolution of 50ms. Dynamic microvascular flow imaging using TrueSTAR is able to follow hemodynamic changes during visual cortex activation every 85ms. Yi Wang1,2, Allison Payne3, Seong-Eun Kim3, Edward DiBella3, Dennis L. Parker3 1Bioengineering, University of Utah, Salt Lake City, UT, United States; 2Utah Center for Advanced Imaging Research , University of Utah, Salt Lake City, UT, United States; 3Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States The Pennes bioheat transfer equation (BHTE) is the most widely used equation to model the effects of heat deposition and dissipation in tissues. The formulation includes terms for thermal conductivity and an effective perfusion, which represents the rate at which blood flow removes heat from a local tissue region. MR thermometry has allowed accurate estimations of these subject-specific thermal properties. Using these estimated parameters enables more accurate treatment planning. However, tissue properties, particularly perfusion, are known to change over the course of a thermal therapy treatment. Detecting perfusion changes during a thermal therapy treatment would allow for the adjustment of treatment parameters to achieve a more efficacious therapy. In this work, we present a method to use arterial spin labeling to determine the rate at which flow passes through a point. The pulse sequence combines the turbo-FLASH imaging and Look-Locker-like readout at multiple inversion times in a single scan. The data obtained from this newly developed sequence approximates the average velocity of blood (fluid) passing through a thin slice, providing a surrogate for the Pennes perfusion term. This method is independent of MR thermometry, decoupling the blood flow measurement from the MR temperature maps, allowing the perfusion changes to be monitored throughout the thermal therapy session. 1775. Dynamic 3D Spin-Labeling MRA for Evaluation of Vascular Territory Inflow Ek Tsoon Tan1, Norbert G. Campeau1, John Huston III1, Stephen J. Riederer1 1Radiology, Mayo Clinic, Rochester, MN, United States The 3D spin-labeling MRA technique, fast inversion recovery (FIR-MRA) provides excellent vessel conspicuity and venous suppression. To incorporate temporal information with high spatial resolution for intracranial imaging at 3T, we developed a variation of the 3D FIR-MRA sequence with segmented acquisitions of four time frames during the gradient echo readout. Scan time is five minutes. Initial feasibility studies show progressive filling of vascular distributions in the subtracted angiograms, along with varying tissue contrasts in the unsubtracted images. This capability may be useful in the setting of infarction, vascular stenoses, arteriovenous malformations and aneurysms. David Dawei Ding1, Jia Guo2, Eric C. Wong3,4 1School of Medicine, University of California - San Diego, La Jolla, CA, United States; 2Department of Bioengineering, University of California - San Diego, La Jolla, CA, United States; 3Department of Radiology, University of California - San Diego, La Jolla, CA; 4Department of Psychiatry, University of California - San Diego, La Jolla , CA, United States This study measures the distribution of brain arterial blood velocity. Five subjects were scanned using velocity selective ASL. The velocity cut off of the image acquisition was held constant at 2cm/sec while the velocity cut off of the tag was 2, 4, 8, 16, 32, and 64cm/sec. The arterial blood fraction in each velocity bin was calculated, and showed that 60% of the blood flow is below 32cm/sec, with about 10% above 64 cm/sec. This data may help to optimize the design of velocity selective inversion pulses, and may be useful in the study of cerebral vascular physiology. Arterial Spin Labeling: Non-Brain Hall B Tuesday 13:30-15:30 Nathan S. Artz1, Andrew L. Wentland1, Elizabeth A. Sadowski2, Thomas M. Grist, 12, Arjang Djamali3, Sean B. Fain1,2 1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Radiology, University of Wisconsin-Madison, Madison, WI, United States; 3Nephrology, University of Wisconsin-Madison, Madison, WI, United States Two methods of measuring cortical kidney perfusion, fluorescent microspheres and ASL-FAIR, are compared for 11 swine each at four interventional time points: 1) under baseline conditions, 2) during an acetylcholine and fluid bolus challenge to increase perfusion, 3) initially after switching to isoflurane anesthesia , and 4) after two hours of isoflurane anesthesia. Across all swine, microspheres and ASL correlated (r = 0.72) and each technique tracked the expected perfusion changes due to the interventions, demonstrating statistical differences in perfusion (p < 0.05) between time points. In addition, ASL perfusion data was more consistent across swine. This data provides validation of ASL-FAIR for relative renal perfusion imaging, especially for evaluating time-averaged perfusion changes that may be observed in chronic disease. 1778. Arterial Spin Labelling Characterisation of Renal Medullary Perfusion Philip M. Robson1, David C. Alsop1 1Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States Arterial spin labelling (ASL) has recently been used for measuring renal perfusion. Perfusion is highest in the renal cortex, but the outer medulla is the most prone to hypoxic injury. Accurate quantification of outer medullary perfusion can be complicated by partial volume averaging with cortical signal and by loss of label in the cortex before transit to the medulla. Here we evaluate high resolution ASL MRI with different labelling strategies to assess the feasibility of quantifying outer medullary perfusion with ASL. 1779. Quantitative Mouse Renal Perfusion Imaging Using Arterial Spin Labeling Reshmi Rajendran1, Cai-Xian Yong1, Jolena Tan1, Jiongjiong Wang2, Kai-Hsiang Chaung1 1Lab of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore; 2University of Pennsylvania, United States Synopsis We demonstrated quantitative renal perfusion in mice using ASL MRI. Perfusion was measured using a FAIR spin-echo EPI. Respiratory motion, susceptibility and fat artifacts were controlled by triggering, high-order shimming, and water excitation, respectively. High perfusion signal was obtained in the cortex compared to the medulla and signal was absent in scans carried out post mortem. Change in the cortical perfusion was observed after manipulating gas compositions including 5% CO2. 1780. Image Registration in ASL-Perfusion Imaging of Kidney - Impact on Image Quality Kiril Schewzow1, Frank Gerrit Zöllner1, Niels Oesingmann2, Lothar Rudi Schad1 1Department of Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Siemens Healthcare, New York, United States ASL techniques suffer from low SNR and especially in abdominal imaging, from organ movements, e.g. breathing. In this work, we analyzed the impact of automatic image registration on signal quality and increase of SNR by averaging in ASL kidney perfusion imaging. To evaluate the registration we compared results to manual registration based on landmarks. Both registration techniques improve the image quality significantly. However, the automatic is the preferred method for large data sets. In addition, a higher SNR is reached contributing to reliable quantification. Philip M. Robson1, Ananth J. Madhuranthakam2, David C. Alsop1 1Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 2Applied Science Laboratory, GE Healthcare, Boston, MA, United States Most studies using arterial spin labelling (ASL) for perfusion in the abdomen have used 2D acquisitions in a limited number of slices. We evaluated 3D Fast Spin Echo (3D FSE) imaging for volumetric acquisition of perfusion in the kidneys. In sagittal image volumes over each kidney, isotropic 2.6-mm resolution was achieved allowing assessment in any orientation. Quantitative perfusion values were found to be comparable to a 2D ASL single-shot FSE sequence, and gave values for total renal blood flow that are in broad agreement with physiological values. 1782. Layer-Specific Blood-Flow MRI of Retina Degeneration at 11.7T Guang Li1, Bryan De La Garza2, Eric Raymond Muir, 2,3, Timothy Q. Duong4 1Research Imaging Institute, Ophthalmology/Radiology, UT Health Science Center at San Antonio, San Antonio, TX, United States; 2Research Imaging Institute, UT Health Science Center at San Antonio, San Antonio, TX, United States; 3Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States; 42Research Imaging Institute, Ophthalmology/Radiology, UT Health Science Center at San Antonio, San Antonio, TX, United States Vision loss due to retinal degeneration is a major problem in ophthalmology. We have previously reported a thinning of the retina and perturbed BOLD fMRI responses to physiologic challenges in the retina of an animal model of progressive retinal degeneration, Royal-College-of-Surgeons (RCS) rats. In this study, we extend previous findings by developing layer-specific basal blood flow (BF) MRI to investigate BF changes in RCS rat retinas and age-matched controls at 43 x 43 x 600 um3 on 11.7T. Quantitative BF was measured using the continuous arterial-spin-labeling technique. MRI provides layer-specific quantitative BF data without depth limitation and a large field-of-view. DSC Perfusion: Acquisition Methods Hall B Wednesday 13:30-15:30 1783. Dynamic Susceptibility Contrast Imaging Using a Multi-Echo Spiral Sequence Nicolas Pannetier1,2, Thomas Christen1,2, Mohamed Tachrount1,2, Benjamin Lemasson1,3, Regine Farion1,2, Sebastien Reyt1,2, Nicolas Coquery1, Christoph Segebarth1,2, Chantal Remy1,2, Emmanuel Louis Barbier1,2 1Inserm, U836, Grenoble, France; 2Université Joseph Fourier, Grenoble Institut des Neurosciences, UMR-S836, Grenoble, France; 3Oncodesign Biotechnology, Dijon, France To characterize microvasculature, one can perform a DCE-MRI followed by a DSC-MRI experiment. However, estimates from a DSC experiment performed after a DCE-MRI experiment differ from estimates derived from a single DSC experiment, especially due to different T1. In this study, we investigate how T1 effect contributes to rCBV estimates in the case of one and two consecutive injections of contrast agent (CA). Thus, we used a multi echo spiral sequence in a rat glioma model. Results suggest that DSC-MRI performed during a second injection of CA is less sensitive to T1 effects than DSC-MRI performed during a first injection. Emelie Lindgren1, Linda Knutsson1, Danielle van Westen2,3, Karin Markenroth Bloch4, Freddy Ståhlberg1,3, Ronnie Wirestam1 1Department of Medical Radiation Physics, Lund University, Lund, Sweden; 2Center for Medical Imaging and Physiology, Lund University Hospital, Lund, Sweden; 3Department of Diagnostic Radiology, Lund University, Lund, Sweden; 4Philips Medical Systems, Lund, Sweden The phase shift during a contrast-agent bolus passage is assumed to be proportional to the concentration of contrast agent. In this study, phase-shift curves in tissue and artery were registered and a phase-based perfusion index and grey-matter MTT were calculated. The relationship between the phase-based perfusion index and ASL CBF estimates showed good linear correlation (r=0.81). The mean grey-matter MTT was 5.4 s, consistent with literature values. Phase-based absolute quantification of CBF is difficult, but the use of a phase-based perfusion index for rescaling of DSC-MRI results can potentially be of value to achieve more robust and reproducible DSC-MRI estimates. 1785. T1-Independent Vessel Size Imaging with Multi-Gradient- And Spin-Echo EPI Heiko Schmiedeskamp1, Matus Straka1, Diane Jenuleson2, Greg Zaharchuk1, Roland Bammer1 1Lucas Center, Department of Radiology, Stanford University, Stanford, CA, United States; 2Stanford University Medical Center, Stanford, CA, United States Vessel size imaging is a relatively new technique that relates contrast agent-induced changes of transverse relaxation rates, R2 and R2*, to each other to obtain an index that provides information about the size of vessels within a voxel of interrogation. Ideally, such measurements require the simultaneous acquisition of multiple gradient-echo (GE) and a spin-echo (SE) signals. However, limiting the acquisition to one GE and SE induces T1-related errors in the vessel size estimation. This problem can be solved by acquiring multiple GE/SE-signals, from which one can derive T1-independent estimates of R2 and R2* from before and during contrast-agent passage. Linda Knutsson1, Freddy Ståhlberg1,2, Ronnie Wirestam1, Matthias Johannes Paulus van Osch3 1Department of Medical Radiation Physics, Lund University, Lund, Sweden; 2Department of Diagnostic Radiology, Lund University, Lund, Sweden; 3Department of Radiology, Leiden University Medical Center, Leiden, Netherlands A linear relationship between the δR2* and contrast agent concentration in blood is often assumed, however, calibration measurements in whole blood have shown that a non-linear relation between δR2* and contrast agent concentration exists. In this evaluation of CBF data, we compared absolute CBF obtained using DSC-MRI and Xe-133 SPECT, using both a linear relationship and a non-linear relationship when applying a venous output function (VOF) correction scheme to DSC-MRI data from healthy subjects. The results showed that the observed degrees of correlation were similar when the linear and non-linear relationships were applied to the AIF and VOF from DSC-MRI. DSC Perfusion: AIF Detection Hall B Thursday 13:30-15:30 1787. Robust Arterial Input and Venous Output Function Detection for Automatic Processing in DSC-MRI Matus Straka1, Gregory W. Albers2, Roland Bammer1 1Radiology, Stanford University, Stanford, CA, United States; 2Stroke Center, Stanford University Medical Center, Stanford, CA, United States Routine acquisition of DSC-MRI PWI datasets highly benefits from full automated post-processing. Selection of arterial input and venous output function is a key step that ensures robustness and reliability of unsupervised processing. A novel method of AIF and VOF selection is proposed by means of tubular filtering and simple analysis of mean temporal signals. Weighting factors the favor arterial and venous signals, as well as vessel orientations are derived. As a result, robustness of AIF and VOF selection was improved. Kathleen E. Chaffee1, Joshua S. Shimony1, G. Larry Bretthorst1, Joel R. Garbow1 1Radiology, Washington University, Saint Louis, MO, United States DSC MRI provides valuable perfusion parameters that correlate with brain tumor progression, but requires a difficult to measure arterial input function (AIF). Using a modification of standard tracer kinetics applied to a tissue perfusion model allows both the AIF and residue curve to be determined for each pixel. The parameters are estimated by Bayesian probability theory using Markov chain Monte Carlo simulations to sample the joint posterior probabilities for the parameters. Here we report DSC MRI investigations on a mouse gliomas that demonstrates characteristic perfusion parameters that do not require an independent measurement of an AIF.
1789. Improving and Validating a Local AIF Method Lisa Willats1, Soren Christensen2, Henry Ma3, Geoffrey Donnan4,5, Alan Connelly1,5, Fernando Calamante1,5 1Brain Research Institute, Florey Neuroscience Institutes (Austin), Melbourne, Australia; 2Department of Radiology, University of Melbourne, Australia; 3National Stroke Research Institute, Florey Neuroscience Institutes (Austin), Melbourne, Australia; 4Florey Neuroscience Institutes , Melbourne, Australia; 5Department of Medicine, University of Melbourne, Australia In bolus tracking the perfusion errors associated with bolus delay/dispersion may be minimised using a local Arterial Input Function (AIF) analysis. We improve a previously presented local AIF method by minimising the influence of the Mean Transit Time (MTT) on the local AIF selection. This is particularly important for identifying local AIFs in regions bordering normal and abnormal MTT tissue. We assess the improvement by comparing the amount of delay/dispersion remaining in the deconvolved tissue response after each local AIF approach, and compare both methods with the standard global AIF analysis.
Aleksandra Maria Stankiewicz1,2, Ona Wu2, Thomas Benner2, Robert E. Irie2, Tracy T. Batchelor2, A Gregory Sorensen2 1Harvard University, Cambridge, MA, United States; 2Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States Perfusion-weighted Magnetic Resonance (MR) Imaging is used to assess the risk of tissue infarction in acute stroke patients and tumor angiogenesis in cancer patients. We compared circular global arterial input function (AIF) and local AIF algorithms, recently proposed automated methods for MR signal deconvolution. 13 patients with 2 MR scans within 48 hours were studied. The variation between global AIF cerebral blood flow (CBF) maps from the first and second scans was 0.220 ± 0.043, and between local AIF CBF maps was 0.263 ± 0.041 (P-value = 0.0015). Superior repeatability of global AIF-based CBF maps may be important in speedy diagnosis and risk stratification. DSC Perfusion: Processing Methods Hall B Monday 14:00-16:00 Kohsuke Kudo1, Soren Christensen2, Makoto Sasaki1, Matus Straka3, Shunrou Fujiwara1, Kinya Ishizaka4, Yuri Zaitsu4, Noriyuki Fujima4, Satoshi Terae4, Kuniaki Ogasawara5, Leif Ostergaard6 1Advanced Medical Research Center, Iwate Medical University, Morioka, Iwate, Japan; 2Departments of Neurology and Radiology, University of Melbourne, Melbourne, Australia; 3Department of Radiology, Stanford University, CA, United States; 4Department of Radiology, Hokkaido University Hospital, Sapporo, Japan; 5Department of Neurosurgery, Iwate Medical University, Morioka, Iwate, Japan; 6Department of Neuroradiology, Aarhus University Hospital, Aarhus, Denmark A variety of post-processing programs and algorithms for dynamic susceptibility contrast (DSC) MR perfusion are available; however, the accuracy and reliability of these programs have not been subject to a standardized quality control. We developed digital phantom data set, to evaluate the accuracy and characteristics of quantitative values derived from DSC perfusion analysis software. By using this phantom, we could check tracer-delay dependency for CBF, CBV, MTT, and Tmax, as well as linearity of CBF and MTT against true values. 1792. Spin Echo Amplitude in Biological Tissue with Implications for Vessel Size Imaging Valerij G. Kiselev1 1Medical Physics, Dpt. of Diagnostic Radiology, University Hospital Freiburg, Freiburg, BW, Germany Transverse relaxation in living tissue is contributed by the dephasing of spins due to diffusion in mesoscopic magnetic fields induced, for example, by paramagnetic tracer in the blood pool. The associated correlation time is commensurate with the echo time of typical measurement sequences. Varying the echo time changes the character of dephasing from reversible for short TE to irreversible for long TE. This dependence is quantified by calculating the transverse relaxation rate in the capillary network for multiple refocusing pulses in the static dephasing regime. This yields a modified formula for the mean vessel size in the vessel size imaging. 1793. Equivalence of CBV Measurement Methods in DSC-MRI Matus Straka1, Gregory W. Albers2, Roland Bammer1 1Radiology, Stanford University, Stanford, CA, United States; 2Stroke Center, Stanford University Medical Center, Stanford, CA, United States Two widely used methods exist for computing cerebral blood volume (CBV) in DSC-MRI perfusion, using measured signals as well as deconvolved residue function. Some authors claim that these methods do not deliver identical results. We explain that the methods must deliver equivalent results and any difference in obtained values is just caused by signal post-processing errors and wrong interpretation of indicator-dilution theory and convolution theorem. Identity of the two methods is shown in time- and frequency-domains as well as by means of numerical results. Possible sources of the processing errors are discussed and solutions how to avoid those are proposed. 1794. Design of a Data Driven Deconvolution Filter for DSC Perfusion Philipp Emerich1, Peter Gall1, Birgitte Fuglsang Kjųlby2, Elias Kellner1, Irina Mader3, Valerij Kiselev1 1Medical Physics, University Hospital Freiburg, Freiburg, Germany; 2Dept. of Neuroradiology, Arhus University Hospital, Arhus, Denmark; 3Dept. of Neuroradiology, University Hospital Freiburg, Freiburg, Germany Bolus tracking perfusion evaluation relies on the deconvolution of a tracer concentration time-courses in an arterial and a tissue voxel following the tracer kinetic model. The object of this work is to propose a method to design a data driven Tikhonov regularization filter in the Fourier domain and to compare it to the singular value decomposition (SVD) based approaches using the mathematical equivalence of Fourier and circular SVD (oSVD). 1795. On the Form of the Residue Function for Brain Tissue Peter Gall1, Valerij Kiselev1 1Medical Physics, University Hospital Freiburg, Freiburg, Germany The residue function, R(t), is fundamental for description of microcirculation. To define this function is one of the aims of DSC perfusion MRI. It is found by solving an ill-posed problem, the deconvolution, for which one of approaches is to fit a model R(t) to data. Commonly, phenomenological functional shapes are used to model R(t) respecting only its most general properties. Studies based on ASL indicate insufficiency of this approach. In this work we present a derivation the residue function from the laws of laminar flow and a model for the architecture of the vascular tree. MR-Guided Focused Ultrasound Hall B Tuesday 13:30-15:30 1796. MR-Guided Focused Ultrasound Ablation of the Rat Liver Randy Lee King1,2, Viola Rieke1, Kim Butts Pauly1 1Department of Radiology, Stanford University, Stanford, CA, United States; 2Department of Bioengineering, Stanford University, Stanford, CA, United States This study investigates the use of a rat model for the MR-guided focused ultrasound treatment of hepatocellular carcinoma. PRF-thermometry, thermal dose calculation and post-ablation imaging are used to determine the ablated liver area and compared to necropsy. Thermal dose reliably predicts the ablated area for single sonications, but care has to be taken to avoid overestimation in lesions resulting from multiple sonications. Seung-Schik Yoo1, KwangIk Jung1, YongZhi Zhang1, Nathan McDannold1, Alexander Bystritsky, 12, Ferenc A. Jolesz1 1Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; 2Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States We showed the evidence of MRI-guided focused ultrasound can suppress the ictal actvity induced by the chemical kindling of rat brain via kainic acid. This evidence demonstrate that non-invasive suppression of epilepsy may be feasible using pulsed, low-energy focused ultrasound. Elizabeth Hipp1, Xiaobing Fan1, Ari Partanen2, Gregory S. Karczmar1 1Radiology, University of Chicago, Chicago, IL, United States; 2Philips Healthcare MR-HIFU is emerging as a treatment modality for a variety of pathologies. Treatments near tissue interfaces can result in unwanted heating caused by an impedance mismatch. This research uses the proton resonance frequency measured by MRI to explore the changes in heating pattern and shift in sonication focus as a result of proximity to an interface in a thermal phantom. Air, acrylic, rubber and a tissue-equivalent gel pad were tested with treatment cells focused at 1, 2 and 4 cm from the interface material revealing 0.7 to 3 mm shifts depending on focal position and interface material. Meaghan Anne O'Reilly1, Yuexi Huang1, Kullervo Hynynen1,2 1Imaging Research, Sunnybrook Research Institute, Toronto, Ontario, Canada; 2Medical Biophysics, University of Toronto, Toronto, Ontario, Canada Ultrasound monitoring of MR-guided transcranial ultrasound therapy could help identify control parameters to better deliver therapy to the brain. An MR-compatible PVDF hydrophone with a high sensitivity was constructed and characterized. The hydrophone was used to monitor microbubble-mediated ultrasound disruption of the blood-brain barrier in rats. Comparison of captured acoustic emissions with T1w and T2w images demonstrated that the hydrophone was able to detect differences in acoustic emissions in sonications producing different bioeffects. The results show promise for real-time monitoring of MRI-guided transcranial therapy. Rachel R. Bitton1, Elena Kaye1,2, Bruce Daniel1, Kim Butts Pauly1 1Radiology, Stanford University, Palo Alto, CA, United States; 2Electrical Engineering, Stanford University, Palo Alto, CA, United States Physicians are increasingly confronted with non-palpable breast lesions only visible on MRI. This study examined the visibility and palpability of focused ultrasound lesions in fatty human breast tissue. Eighteen sonications were made around the perimeter of an arbitrary prescribed tumor square, representing a non-palpable tumor area. Potential stiffness changes were measured using MR-ARFI showing the displacement difference between the pre and post sonication. The lesions were fully registered with images, circumscribing a tumor area in a human cadaver breast, and thus, providing a visible and palpable perimeter for a surgeon as a guide for excision during breast conservation surgery. Jun-Cheng Weng1,2, Sheng-Kai Wu3, Win-Li Lin3,4, Wen-Yih Iascc Tseng1,5 1Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan; 2Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan; 3Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan; 4Medical Engineering Research Division, National Health Research Institutes, Miaoli, Taiwan; 5Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan Focused ultrasound (FUS) along with an ultrasound contrast agent (UCA) can induce transient and local increase in the permeability of blood vessel wall or cell membrane, and the change in blood-brain barrier (BBB) permeability can be appropriately indicated by contrast-enhanced MRI. Recently, most studies have used optimum FUS parameters with intravascular injection of pre-formed micro-bubbles to produce BBB disruption with minimum damage to the neurons. However, there are no studies reporting that under biosafety regime BBB disruption could still be predicted by MR contrast enhancement. The purpose of this study was to see if the traditional T1-weighted (T1W) imaging sequences, spin echo (SE) and gradient echo (GE), can discern the difference in the BBB disruption in lower dose regime or not. A high sensitivity R1 mapping was used as a gold standard and absolutely quantification. The quantitative analysis indexing the degree of BBB disruption and the correlation against Evans blue (EB) staining were also demonstrated. Our results suggest that, in the absence of hemorrhage, contrast-enhanced T1W gradient echo and spin echo sequence were equally reliable in quantifying the BBB disruption. 1802. Analysis of Focused Ultrasound Hotspot Appearance on EPI and Spiral MR Imaging Sonal Josan1, Andrew B. Holbrook, 12, Elena Kaye, 1,3, Christine Law, 1,3, Kim Butts Pauly1 1Radiology, Stanford University, Stanford, CA, United States; 2Bioengineering, Stanford University, Stanford, CA, United States; 3Electrical Engineering, Stanford University, Stanford, CA, United States MR thermometry relies on the proton resonance frequency shift with temperature, which can produce off-resonance artifacts in EPI and spiral sequences. This work analyzed the appearance of the focused ultrasound (FUS) hotspot on several EPI and Spiral trajectory designs through simulations and FUS experiments. The distortion of the FUS spot with single shot EPI or Spiral imaging can be severe for the high temperature changes used in ablation, and may lead to under-estimation of the peak temperature. Multi-shot sequences can be used to reduce the shifts/distortion to a tolerable level. Loredana Baboi1, Magalie Viallon1, Sylvain Terraz1, Thomas Goget1, Denis Morel2, Christoph Becker1, Rares Salomir1 1Department of Radiology, University Hospital of Geneva, Geneva, Switzerland; 2Department of Anesthesiology, Pharmacology and Surgical Intensive Care, University Hospital of Geneva, Geneva, Switzerland MRgHIFU is a hybrid technology which aims to offer efficient and safe thermal ablation of targeted tumors or other pathological tissues, while preserving the normal surrounding structures unaltered. Theoretically MRgHIFU has no limitation on lesion size [1]. The main challenge is to avoid near and far field heating [2]. We demonstrate here that beam reflection on bones is a major problem whenever bone is situated in the proximity of the prescribed region for sonication, even laterally from the main beam axis. This study evaluates selective de-activation of phased-array transducers elements as a potential strategy to reduce bone reflection. M Viallon1, JN Hyacinthe1, T Goget1, L Baboi1, P Gross2, CD Becker1, R Salomir1 1Radiologie, Hopital Universitaire de Genčve, Geneva, Switzerland; 2Siemens Medical Solutions, Erlangen, Germany One challenge in MRgHIFU is to provide safe and thermally neutral focusing of HIFU beam pattern using acoustic radiation force imaging (ARFI). The radiation force is localized and highly directional (along the main propagation axis of the HIFU beam) while negligible outside the focal zone. This force initiates a tissue displacement correlated to the amplitude of the acoustic field and thus a phase shift that can be encoded in the MR signal using a motion encoding gradient (MEG) [1]. In addition, ARFI also provide stiffness weighted images that may allow one to assess for pre- versus post- therapy changes in tissue. Since HIFU also causes tissue heating, temperature elevation and RFI effects are always associated, at various degree. We propose here to obtain a precise localization of the HIFU focal point by subtracting GRE phase images from two independent acquisitions, where ARF-induced phase shift is sequentially encoded with positive and, respectively, negative monopolar MEG pulse. For illustration, the MEG was implemented here along the slice-select direction. 1805. Does Proton Resonance Frequency Linearly Change with Temperature? Donghoon Lee1, Kenneth Marro1, Bryan Cunitz1, Michael Bailey1 1University of Washington, Seattle, WA, United States To improve the accuracy in temperature measurements over a wide temperature region (20 95 C), we designed and fabricated a test sample holder and conducted temperature measurements over the temperature range. The test sample holder comprised a reference chamber for temperature reference and a heating chamber. Both chambers, filled with water, were in well thermal insulation. Nonlinear relationship between proton resonance frequency shift and temperature was observed for the wide temperature region. Accurate information of temperature variations over a wide temperature region would be valuable to thermal therapy for a temperature region that could reach the water boiling temperature. 1806. Temperature Sensitive Liposomes for Drug Delivery with MRI-HIFU Mariska de Smet1, Sander Langereis2, Roland van de Molengraaf2, Edwin Heijman2, Nicole Hijnen1, Holger Gruell1,2 1Biomedical NMR, Eindhoven University of Technology, Eindhoven, Netherlands; 2Biomolecular Engineering, Philips Research Eindhoven, Eindhoven, Netherlands Temperature sensitive liposomes (TSL) incorporating both a chemotherapeutic drug, i.e. doxorubicin, and a clinically approved MRI contrast agent, [Gd(HPDO3A)(H2O)] were prepared and evaluated for MR image guided drug delivery. A gel phantom was prepared containing spots of agarose gel mixed with the liposomes. Before and after heating with High Intensity Focused Ultrasound (HIFU), a T1 map was obtained with a Look-Locker EPI-sequence. When heated above the phase transition temperature, the TSLs showed a rapid release of both the drug and contrast agent. The spots with liposomes which were heated with HIFU clearly showed a lower T1 after ultrasound application. 1807. Latency Compensation for Real-Time 3D HIFU Beam-Steering on Moving Targets Mario Ries1, Baudouin Denis de Senneville1, Sébastien Roujol1, Chrit Moonen1 1laboratory for molecular and functional imaging: from physiology to therapy, CNRS/ University Bordeaux 2, Bordeaux, Aquitaine, France Dynamic beam-steering of high intensity focused ultrasound (HIFU) based on MR-guidance is a promising technology for the non-invasive ablation of pathological tissue in abdominal organs such as liver and kidney. A particular problem of this technique remains the intrinsic latency between the position measurement and the beam update, which leads to undesired energy dispersion and potentially to the destruction of non-pathological tissue. In this study, dynamic beam-steering using a robust Kalman-predictor for 3D motion anticipation is evaluated experimentally. Nick Todd1, Josh De Bever2, Urvi Vyas3, Allison Payne4, Dennis L. Parker5 1Physics, University of Utah, Salt Lake City, UT, United States; 2Robotics, University of Utah, Salt Lake City, UT, United States; 3Bioengineering, University of Utah, Salt Lake City, UT, United States; 4Mechanical Engineering, University of Utah, Salt Lake City, UT, United States; 5Radiology, University of Utah, Salt Lake City, UT, United States For certain MR thermometry applications, such as tissue property determination or total accumulated thermal dose calculations, retrospectively reconstructed temperature maps are acceptable. For such purposes, we have implemented a temporally constrained reconstruction method. The technique uses the entire dynamic imaging data set and an iterative cost function minimization algorithm to create 3-D temperature maps with high spatial resolution (~1 - 2mm3), high temporal resolution (~1 sec), and large field of view coverage (~26x16x3cm3). We present the TCR method and applications to retrospective determination of tissue thermal conductivity, ultrasound power deposition, and total accumulated thermal dose. Hsu-Hsia Peng1, Teng-Yi Huang2, Hsiao-Wen Chung3, Po-Cheng Chen4, Yu-Hui Ding4, Shiun-Ying Ju2, Yao-Hao Yang2, Wen-Yih Isaac Tseng5,6, Wen-Shiang Chen4,7 1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan; 2Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; 3Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan; 4Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei, Taiwan; 5Center for Optoelectronic Biomedicine, Medical College of National Taiwan University, Taipei, Taiwan; 6Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan; 7Division of Medical Engineering Research, National Health Research Institutes, Miaoli, Taiwan During HIFU treatment, the focus of ultrasound (US) is arranged to the targeting region determined in advance. In practical treatments, however, the focus might be deviated due to the complex path (tissue-bone interface or tissue-air interface) of US beams. For safety considerations, accurate localization of heating focus is important before performing HIFU treatment. In this study, a spherical model is proposed to estimate the real position of US focus. A low power pre-treatment experiment was performed on ex vivo porcine muscle. The estimated focus position was verified via magnetization transfer ratio images after a high power HIFU transmission. Urvi Vyas1, Nick Todd2, Allison Payne3, Douglas Christensen, Dennis L. Parker4 1Bioengineering, University of Utah, Salt Lake City, UT, United States; 2Physics, University of Utah; 3Mechanical Engineering, University of Utah; 4Radiology, University of Utah An inverse parameter estimation technique that non-invasively determines ultrasound tissue properties ( speed of sound, attenuation) using MRI temperature maps of low level ultrasound heating pulses is presented. The properties determined by the new technique are compared to ultrasound tissue properties measured using the transmission-substitution technique. 1811. MR-Guided Unfocused Ultrasound Disruption of the Rat Blood-Brain Barrier Kelly Ann Townsend1, Randy L. King1, Greg Zaharchuk2, Kim Butts Pauly1,2 1Bioengineering, Stanford University, Stanford, CA, United States; 2Radiology, Stanford University, Stanford, CA, United States The purpose of this study was to investigate the effects of unfocused ultrasound on blood-brain barrier opening across the whole brain using contract enhanced-MRI. T1-weighted FSE images of the brain were acquired in rats for several minutes after gadolinium administration and unfocused ultrasound whole brain treatment. Signal increased immediately after sonication, and continued to increase in the brain as time passed, while muscle signal decreased due to washout. Our findings demonstrate that unfocused ultrasound sonication can disrupt the blood-brain barrier across the whole brain, including cortex and deep grey matter nuclei. This can be observed using contrast-enhanced MRI. Hsu-Hsia Peng1, Teng-Yi Huang2, Hsiao-Wen Chung3, Shiun-Ying Ju2, Yao-Hao Yang2, Po-Cheng Chen4, Yu-Hui Ding4, Wen-Shiang Chen4, Wen-Yih Isaac Tseng5 1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan; 2Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; 3Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan; 4Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei, Taiwan; 5Center for Optoelectronic Biomedicine, Medical College of National Taiwan University, Taipei, Taiwan In this study, an imaging sequence, which simultaneously monitors temperature change and magnetization transfer (MT) contrast at 2-sec temporal resolution, was applied on rabbit thigh muscle during HIFU sonicaiton to verify in vivo feasibility. The characteristics of better immunity to phase variance (in contrast to temperature mapping derived from phase images) and clear distinction between heated spot (4.29%”Ó0.41%) and non-heated region (-0.19%”Ó0.30%) of MT, even after turning off HIFU pulse, suggest its usefulness in long-term monitoring. In conclusion, MRI with simultaneous temperature and MT mapping is an effective technique to evaluate tissue damage for HIFU treatment. Adam Christian Waspe1,2, Anthony Chau1, Rajiv Chopra1,2, Kullervo Hynynen1,2 1Imaging Research Discipline, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; 2Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada An MR-compatible system was developed for performing focused-ultrasound exposures in preclinical models. A focused-ultrasound transducer attaches to the positioning system and is submerged within a closed water tank. Sonicating a phantom and measuring the thermal focal zone registers ultrasound and MRI coordinates. For each axis, a 5 cm travel and 0.1 mm positioning resolution was achieved. The system was constructed with non-magnetic components and operation of the focused-ultrasound system within the bore during imaging did not result in any mutual interference. This system is used to study the applications of ultrasound energy for novel therapeutic applications in preclinical animal models. Line Souris1, Najat Salameh1, Matthias Korn1, Laurent Marsac2, Jean-Franēois Aubry3, Mathieu Pernot3, Mickael Tanter3, Luc Darrasse1 1Imagerie par Résonance Magnétique Médicale et MultiModalité (UMR 8081), Université Paris-Sud, CNRS, Orsay, France; 2SuperSonic Imagine, Aix en Provence, France; 3Institut Langevin, ESPCI ParisTech, CNRS UMR 7587, INSERM U979, Paris, France MRI is a well-suited candidate for temperature monitoring during the heating with transcranial HIFU. For this application, the body coil is usually used because of the constraints due to the large sized of the HIFU system and the stereotactic frame surrounding the patient head. This study showed the improvement of image quality, and therefore temperature sensitivity, by using a dual Flex-coil arrangement. Further improvement is possible by designing dedicated coil arrays with a larger number of coil elements and integrated EMI filters within the coil architecture to reject any interference of the HIFU shots with the MR signal.
1815. MR Guided High Intensity Focused Ultrasound for Tumor Ablation in Brain: Preliminary Results Najat Salameh1, Line Souris1, Laurent Marsac2, Jean-Franēois Aubry3, Mathieu Pernot3, Benjamin Robert2, Mathias Fink3, Luc Darrasse1, Mickaėl Tanter3 1Imagerie par Résonance Magnétique Médicale et MultiModalité (UMR 8081), Université Paris-Sud, CNRS, Orsay, Iles-de-France, France; 2SuperSonic Imagine, Aix-en-Provence, France; 3Institut Langevin, ESPCI ParisTech, CNRS UMR 7587 INSERM U979, Paris, France A novel prototype for brain therapy with transcranial focused ultrasound is presented here. The first part of this study showed that this new HIFU system was fully MR-compatible. Secondly, we optimized a sequence for MR thermometry, and followed the increase in temperature in a gel heated with increasing power (from 125 to 500 Wac). Finally, we showed it is possible to heat veal brains through a human skull at a high frequency and monitor the heating process with MRI. After validation on cadaver heads, this work will open new horizons to tumor brain therapy in animals and then in humans. Yi Wang1, Allison Payne2, Seong-Eun Kim2, Edward DiBella2, Dennis L. Parker2 1Bioengineering, University of Utah, Salt Lake City, UT, United States; 2Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States The Pennes' perfusion term in the Pennes bioheat transfer equation depicts the rate at which blood flow removes heat from a point and can play an important role in tissue heat dissipation. Because tissue perfusion is known to change over the course of a thermal therapy treatment, the ability to perform multiple flow assessments to detect perfusion changes during magnetic resonance-guided high-intensity focused ultrasound treatment is of high importance. In this work, we present a method to use arterial spin labeling to determine the Pennes' perfusion term in brain tissue and evaluate performance as a function of various imaging parameters, such as flip angle , bandwidth, and resolution. The results indicate that the proposed technique could be applied in MRgHIFU to provide an efficient estimate of the Pennes' perfusion term. Although demonstrated on brain tissue, this technique could be applied to other tissue types. Thermotherapy Hall B Wednesday 13:30-15:30 1817. Dual-Echo Sequence for MR Thermometry in Moving Objects Bruno Madore1, Lawrence P. Panych1, Chang-Sheng Mei1,2, Renxin Chu1 1Radiology Department, Brigham and Women's Hospital, Harvard Medical School , Boston, MA, United States; 2Department of Physics, Boston College, Chestnut Hill, MA, United States An MR thermometry dual-echo sequence is proposed here that offers advantages both in terms of temperature-to-noise ratio and image contrast, as compared to typically-used sequences. For thermometry in moving organs, the contrast properties of the proposed sequence allow blood vessels to be readily detected, for motion tracking purposes. Kagayaki Kuroda1,2, Taku Iwabuchi, Mie Kee Lam3, Makoto Obara4, Masatoshi Honda5, Kensuke Saito, Marc Van Cauteren4, Yutaka Imai5 1Graduate School of Engineering, Tokai University, Hiratsuka, Kanagawa, Japan; 2Medical Device Development Center, Foundation for Biomedical Research and Innovation, Kobe, Hyogo, Japan; 3Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 4MR Marketing, Philips Electronics Japan Medical Systems, Shinagawa, Tokyo, Japan; 5Department of Radiology, Tokai University, Isehara, Kanagawa, Japan A fat temperature imaging technique based on multiple flip angle, multipoint Dixon acquisitions and a least square estimation scheme is proposed. Gradient recalled acquisition of 5 echo times with 3 different flip angles were obtained to separate the signals of methylene and methyl protons and to estimate T1's of these fatty acid species. Temperature images of a water-oil phantom were successfully obtained with previously obtained temperature coefficients demonstrating the feasibility of quantitative thermometry of fat. Since the acquisition time was 4-6 second, the technique seemed to be practical for temperature monitoring of fat-water tissues like breast under thermal therapies. 1819. Novel Body Coil Driven Radio Frequency Ablation Device Yik-Kiong Hue1, Jerome L. Ackerman1, Erez Nevo2 1Martinos Center, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States; 2Robin Medical, Inc., Baltimore, MD, United States A novel body coil driven radiofrequency ablation (RFA) device is proposed. It provides an alternative to commercial available RFA device which required external power generator and large grounding pad. It allowed MR scanner as the sole modality to localize tumor, probe placement, RF power control, temperature mapping and tissue monitoring. 1820. Temperature and B0 Field Measurment Bias of Multi-Echo Fat-Water Fitting Algorithms Cory Robert Wyatt1, Brian J. Soher2, James R. MacFall2 1Department of Biomedical Engineering, Duke University, Durham, NC, United States; 2Department of Radiology, Duke University Medical Center, Durham, NC, United States Multi-echo fat-water separation techniques, such as IDEAL, have been shown to be effective in measuring temperature changes in fatty tissue, but often make assumptions that allow them to linearize the model in order to simplify the computation of a solution. This can result in the addition of significant bias to the measurement of the temperature and the B0 field offset, both important parameters to monitor during therapeutic heat applications (tumor ablation, hyperthermia). In this work, the bias of a multi-peak IDEAL algorithm (without T2* decay) and a new nonlinear fitting algorithm is characterized using Monte Carlo simulations. Cory Robert Wyatt1, Brian J. Soher2, Kavitha Arunachalam3, James R. MacFall2 1Department of Biomedical Engineering, Duke University, Durham, NC, United States; 2Department of Radiology, Duke University Medical Center, Durham, NC, United States; 3Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States Multi-echo fat-water fitting techniques that separate the fat and water effects have been shown to be useful in measuring temperature in fat-water phantoms. In this study we explore optimization of echo time selection by minimizing the temperature noise using Cramer-Rao Lower Bound (CRLB) analysis. Accuracy of fitting is improved by including multiple fat peaks and T2* effects. Our approach finds the minimum temperature noise that has the minimum sensitivity to the values of nominally fixed parameters. The CRLB results were then confirmed in experiments with fat-water gelatin phantoms. 1822. Measurement of Human Brain Temperature Changes During Cooling Jan Weis1, Lucian Covaciu2, Sten Rubertsson2, Mats Allers3, Anders Lunderquist4, Francisco Ortiz-Nieto1, Håkan Ahlström1 1Department of Radiology, University Hospital, Uppsala, Sweden; 2Department of Surgical Sciences, Anesthesiology and Intensive Care, University Hospital, Uppsala, Sweden; 3Department of Clinical Sciencies, University Hospital, Lund, Sweden; 4Department of Clinical Sciences, University Hospital, Lund, Sweden Decrease of the human brain temperature (1-2 oC in 15 minutes) was induced by intranasal cooling. The purpose of this study was to verify the cooling technique on the volunteers and to compare two methods for noninvasive monitoring of the relative brain temperature: MRSI with high spatial and reduced spectral resolution and PRF shift technique. Ability of the proposed brain cooling technique to induce moderate hypothermia was confirmed. Good agreement was found between relative temperatures measured by MRSI and PRF method. Both temperature mapping techniques can be used for monitoring the brain temperature changes during hypothermia. 1823. Measurement of the Temperature Dependence of the Susceptibility of Human Breast Fat Tissue Sara Maria Sprinkhuizen1, Chris J. Bakker1, Johannes H. Ippel2, Rolf Boelens2, Lambertus Wilhelmus Bartels1 1Radiology, Image Sciences Institute, Utrecht, Netherlands; 2Bijvoet Center for Biomolecular Research, NMR Spectroscopy Research Group, Utrecht, Netherlands In fat tissue, large susceptibility-related PRFS-based temperature errors can be expected, due to temporal changes in tissue susceptibility (χ) which lead to non-local magnetic field changes. This affects the PRF (hence, the measured temperature) of all water protons that experience this magnetic field change, leading to temperature errors. In order to conclusively assess the impact of temperature-induced χ changes on PRFS-based MRT, accurate and precise susceptibility measurements in human tissue are a prerequisite. We therefore measured dχ/dT of fat tissue of the human breast on a 14 T NMR spectrometer. A dependence of 0.0051 ppm/°C was found. Sara Maria Sprinkhuizen1, Chris J. Bakker1, Lambertus Wilhelmus Bartels1 1Radiology, Image Sciences Institute, Utrecht, Netherlands Susceptibility (χ) related field changes are commonly ignored in the application of proton resonance frequency shift (PRFS)-based MR thermometry (MRT) during thermal interventions, even though the temperature dependence of the χ of fat is in the same order of magnitude as the temperature dependence of the chemical shift of water. Its influence on PRFS-based MRT maps was investigated experimentally. The results showed that changes in χ fat hamper the PRFS-based MRT method nonlocally. The measured errors were ranging between -4.6 °C and +4.1 °C. Important to stress is the fact that fat suppression is not a solution for this effect. 1825. Modified Balanced SSFP Sequence for Better Temperature Sensitivity Mahamadou Diakite1, Nick Todd1, Dennis L. Parker2 1Physics, University of Utah, Salt lake, UT, United States; 2Radiology, Utah Center for Advanced Imaging Research (UCAIR), Salt lake, UT, United States Safety and efficacy of tumor treatment using high intensity focus ultrasound requires accurate temperature measurement throughout the thermal procedure. In this work, we investigate how the noise in temperature measurements can be reduced by variations to this new ub-SSFP sequence.
Michael Peller1, Martin Hossann2, Tungte Wang2,3, Steven Sourbron1, Lars H. Lindner2,3 1Institute of Clinical Radiology, University Hospital of Munich, Munich, Germany; 2Department of Internal Medicine III, University Hospital Munich; 3CCG-Hyperthermia, Helmholtz Zentrum München, German Research Center for Environmental Health, Germany Purpose was to investigate the dynamics of mild temperature induced contrast agent release from phosphatidylglyc-eroglycerol containing thermosensitive liposomes with encapsulated Gd-DTPA-BMA (Gd-TSL) in tumor tissue. Tumor bearing mice were investigated at 1.5T after intravenous injection. The temperature induced release of contrast agent at 42°C caused a fast and strong increase of T1-weighted signal. Immediately after i.v. injection heated tumor tissue was distinguishable from unheated tumor and muscle tissue. Unheated muscle tissue may thus be less affected by a potential anti tumor therapy based on TSL. Rares Salomir1, Magalie Viallon1, Sylvain Terraz1, Christoph D Becker1 1Radiologie, Hopital Universitaire de Genčve, Geneva, Switzerland MR thermometry based on the proton resonance frequency (PRF) method (1) has gained good acceptance for guiding RF ablation of liver tumors (2). Major artifacts in the PRFS thermometry have recently been reported related to per-operatory changes of the tissue bulk susceptibility during RF heating (3). They are originating from gas bubbles formation, known as white cavitations artifacts in US imaging. We propose here a theoretical description of the effects and a first order correction that confirm the source of the spatially related errors in temperature maps and TD during power application. 1828. MR Thermometry in Moving Objects Using a Novel Referenceless and User-Independent Approach Bruno Madore1, Renxin Chu1, Chang-Sheng Mei1,2, Lawrence P. Panych1 1Radiology Department, Brigham and Women's Hospital, Harvard Medical School , Boston, MA, United States; 2Department of Physics, Boston College, Chestnut Hill, MA, United States MR thermometry in moving organs is a challenging application, as fairly subtle temperature-induced changes must be accurately measured in the presence of often much larger motion-induced changes. A novel approach at doing so is proposed here, which is both referenceless (does not require a baseline reference image) and user-independent. 1829. Air Susceptibility Effects on Proton Resonance Frequency Temperature Mapping Markus Nikola Streicher1, Andreas Schäfer1, Dimo Ivanov1, Robert Turner1 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany MR thermometry is usually based on the temperature dependence of the proton resonance frequency (PRF), thus any magnetic field changes might be misinterpreted as temperature changes. Here we report on the effects of changes of susceptibility of surrounding air on the magnetic field inside an object. When the air was heated by 46 ŗC, its susceptibility changed from χ air = 3.6×10-7 to χ air = 2.7×10-7, inducing an apparent additional temperature change of 1.9°C inside the object. For a more realistic surrounding air temperature increase of 10°C this could result in an error of 0.75°C. 1830. Real-Time MR-Thermometry and Dosimetry for Interventional Guidance on Abdominal Organs Sébastien Roujol1,2, Mario Ries1, Bruno Quesson1, Chrit Moonen1, Baudouin Denis de Senneville1 1laboratory for molecular and functional imaging: from physiology to therapy, CNRS/ University Bordeaux 2, Bordeaux, Aquitaine, France; 2LaBRI, University Bordeaux 1, Talence, Aquitaine, France A computationally efficient pipeline for 2D motion compensated PRF-thermometry and thermal dose measurements on moving abdominal organs is presented. The method is designed to address both, inter-scan and intra-scan artifacts by applying high frame-rate MRI coupled with a real-time image processing. The proposed MR-thermometry method was evaluated in both liver and kidney of 11 healthy volunteers and achieved a precision of less than 2 °C in 70 % of the pixels. The ability to perform MR-Thermometry and Dosimetry in-vivo was demonstrated on one HIFU-heating experiment on a porcine kidney. 1831. A Self-Reference MR Thermometry Method Utilizing the Phase Gradient Jason A. Langley1,2, Qun Zhao1,2 1Department of Physics and Astronomy, The University of Georgia, Athens, GA, United States; 2Bioimaging Research Center (BIRC), The University of Georgia, Athens, GA, United States A modified self-reference MR thermometry method is presented in this abstract. We circumvent the phase unwrapping procedure in the self-reference MR thermometry procedure by utilizing the phase gradient to estimate the baseline phase map. In the method proposed in this abstract, the phase map is modeled as a 2D polynomial. The components of the gradient of the model are then fitted to the components of the phase gradient using 2D weighted least squares. The proposed procedure is evaluated using two simulated MR thermometry data sets. 1832. First Clinical Experience with Navigated RF Ablations of the Liver in a Closed-Bore 1.5T MRI Daniel Seider1, Harald Busse1, Nikita Garnov1, Gregor Thörmer1, Susann Heinig1, Tim Riedel1, Thomas Kahn1, Michael Moche1 1Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany MRI is well suited to guide percutaneous interventions of liver lesions that are hardly visible with ultrasound or CT. Dedicated open MR systems are often used because they provide good patient access. This work presents first clinical experience with a new navigation solution that was used during RF ablation of liver tumors in a standard closed-bore scanner environment. After a special breathhold training, even double oblique access paths could be realized. RFA probe and thermally induced lesion could be reliably visualized with a VIBE sequence. While technical efforts are higher the times for needle placement and thermal ablation are comparable to those under CT guidance. 1833. Highly Accelerated Temperature Mapping Using Nonlocal Regularized Parallel Imaging Sheng Fang1, Xinyi Pan1, Kui Ying1 1Department of Engineering Physics, Tsinghua University, Beijing, China Model-based MR thermometry method based on the proton resonance frequency shift (PRFS) can effectively improve the temperature estimate accuracy of conventional phase different method. However, its temporal resolution need be improved for real-time temperature monitoring. To solve the problem, we applied highly accelerated PI to temperature mapping and used nonlocal regularization that extracts the prior from the acquired data themselves to stabilize the reconstruction. The method was demonstrated using whipping cream phantom. The results show that the nonlocal regularization can effectively increase the temporal resolution of PRFS while avoiding the introducing the bias to quantification, due to its data-driven property. 1834. Quantitative Analysis for Optimizing the MRI Temperature Monitoring Using Keyhole Technique Yong hee Han1, Kang soo Kim1, Dong Hyuk Kim1, Kwang sik Lee2, Jae Ryang Juhn3, Choong ki Eun3, Chi woong Mun1,4 1Bio medical engineering, Inje University, Gimhae, Gyeongsangnam-do, Korea, Republic of; 2Medical Image Science, Pusan Paik hospital, Korea, Republic of; 3Diagnostic of Radiology Medical School, Pusan Paik hospital, Korea, Republic of; 4Medical Image Research Center, Inje University, Korea, Republic of This study proposes the keyhole method in order to improve the time resolution of the proton resonance frequency (PRF) MR temperature monitoring technique. To evaluate proposed method, the values of Root Mean Square (RMS) error were compared with full phase encoded temperature images. And the paired t-test was performed for optimization at Keyhole technique. As a result of this study, >32 encoded images were reasonable in 95% confidence level whereas <32 encoded images showed statistically significant difference. 1835. Convection Enhanced Delivery of Drugs to the CNS Peter Andrew Hardy1, Zhiming Zhang1, Don Gash1, Doug U. Gwost2, David Stiles2, Brian D. Nelson2, Pei Ge3, Dinah Sah3 1Anatomy & Neurobiology, University of Kentucky, Lexington, KY, United States; 2Medtronic Neurological, Minneapolis, MN, United States; 3Alnylam Pharmaceuticals, Inc., Cambridge, Massachussets, United States Convection Enhanced Delivery is a powerful method of delivering drugs to the CNS. We tested CED hardware and imaging methods by delivering Magnevist at three flow rates to the putamen in rhesus monkeys over a period of 7 days. T1-weighted images were acquired at three time points and from these the volume of distribution was characterized. Results demonstrate a compact distribution to the putamen with a flow rate-dependent volume. 1836. Gd-Labelled Polylysine as a Tracer for Convective Enhanced Delivery Peter Andrew Hardy1, Luke H. Bradley1, Zhiming Zhang1, Don Gash1, Dan Keeley2, Brian Kramer3, Greg Schorn4 1Anatomy & Neurobiology, University of Kentucky, Lexington, KY, United States; 2Advanced Technologies and Regenerative Medicine, Rayntham, MA, United States; 3Advanced Technologies and Regenerative Medicine, Somerville, NJ, United States; 4Advanced Technologies and Regenerative Medicine, Rayntham, Massachussets, United States Convection Enhanced Delivery is a powerful method of delivering drugs to the CNS. MR-visible tracers co-infused with drug will be useful to assess drug distribution. We tested four compounds (Magnevist and three Gd-labeled polylysines) with molecular weights between 0.5k Da and 200 kDa as potential tracers for CED. Compounds were tested in vitro to model CED parameters used to plan delivery into four rhesus monkeys. In vitro results demonstrated MW dependent CED distribution. In vivo results demonstrated distribution of the Magnevist in the putamen but little distribution of the polylysine as a result of binding and digestion of the polylysine. Clinical & Pre-clinical Interventions (Non-thermal) Hall B Thursday 13:30-15:30 1837. Novel Delivery System for Minimally Invasive MR Guided Neurological Interventions Alastair Martin1, Mark Richardson2, Adrian Kells2, John Bringas2, Pete Piferi3, Lisa Tansey3, Geoffrey Bates3, Philip Starr2, Paul Larson2, Krystof Bankiewicz2 1Radiology and Biomedical Imaging, University of California - San Francisco, San Francisco, CA, United States; 2Neurological Surgery, University of California - San Francisco; 3SurgiVision, Inc, Irvine, CA A novel delivery system for MR guided precision minimally invasive access to deep brain structures is presented. A targeting accuracy of 0.5 mm at depths of 85-90mm is achieved in a phantom model. The delivery system is also used to insert cannulas for infusing therapeutic agents via convection-enhanced delivery (CED). CED is demonstrated in a non-human primate with infusions to the thalamus, putamen and sub-thalamic nucleus. Accurate delivery of infusion cannulas was achieved and CED infusions extending up to 10mm in diameter are demonstrated. 1838. Retrograde Drilling of Osteochondral Lesions of the Knee with MRI Guidance Christian Jürgen Seebauer1, Hermann Josef Bail2, Jens Christian Rump3, Ulf Teichgräber3 1Center for Musculoskeletal Surgery, Charité, Berlin, Germany; 2Department of Trauma and Orthopedic Surgery, Clinic Nuremberg, Nuremberg, Germany; 3Department of Radiology, Charité, Berlin, Germany Osteochondritis Dissecans (OD) of the knee is a common articular lesion in adolescents and young adults. Retrograde drilling is an alternative in surgical treatment before more invasive and complex procedures are necessary; however drilling under fluoroscopic guidance via the epiphyses is technically challenging in terms of maintaining drill depth and accuracy of drill placement. The purpose of this study was to evaluate applicability and accuracy of a passive navigation method by drilling a simulated OD target at the knee with MRI guidance. Interactive MR navigation allowed precise drilling of OCD of the knee. Targeting was possible with a single drilling. Matt Smith1, Ethan Brodsky1,2, Steve Kecskemeti1, Xu Zhai1, Sean Fain1,3 1Medical Physics, University of Wisconsin, Madison, WI, United States; 2Radiology, University of Wisconsin, Madison, WI, United States; 3Biomedical Engineering, University of Wisconsin, Madison, WI, United States During an MR-guided breast intervention, placement of a needle or probe requires accurate localization of the target. To allow rapid identification of these errors, avoid unnecessary trauma to the patient, and minimize scanner time, a real-time MR acquisition and display was implemented to allow the physician to monitor both the progress of the insertion and the procedure itself, such as core needle biopsy or tumor ablation. Flexibility was added to adjust the scan plane in real-time and make tradeoffs between update display rate and image quality. Wilhelm Strehl1, Eva Rothgang1,2, Wesley Gilson2, Klaus J. Kirchberg3, Joachim Hornegger1, Christine Lorenz2 1Pattern Recognition Lab, Department of Computer Science, University of Erlangen-Nuremberg, Erlangen, Bavaria, Germany; 2Center for Applied Medical Imaging, Siemens Corporation, Corporate Research, Baltimore, MD, United States; 3Center for Applied Medical Imaging, Siemens Corporation, Princeton, NJ, United States Percutaneous interventions involve the navigation of a needle or probe to a target location. MRI is well-suited to guide these procedures as it offers good soft tissue target visualization and no ionizing radiation. High field wide bore MRI has stimulated interest in performing more of these procedures, but workflow and procedure speed are significant hurdles for full adoption. Here, a navigation tool for guiding and tracking the needle in real-time under MRI is presented. 1841. Navigated Liver Biopsies in a Closed-Bore MR Scanner: First Clinical Experience Michael Moche1, Gregor Thörmer1, Nikita Garnov1, Jochen Fuchs1, Susann Heinig1, Tim Riedel1, Thomas Kahn1, Harald Busse1 1Leipzig University Hospital, Leipzig, Germany MRI has been shown to be of great clinical utility for the guidance of various procedures. In a closed-bore scanner, the simplest approach is to manipulate the instrument outside the bore and move the patient inside for control imaging only. Potential benefits for percutaneous biopsies in the liver have been investigated in 15 patients by using a flexible add-on navigation solution which even allowed interventions in obese patients. Real time navigation was provided by following the virtual instrument on properly reformatted images of a 3D roadmap. In combination with a specific breathhold protocol, punctures could be reliably performed in reasonable times. Steffi Valdeig1, Barry Fetics2, Li Pan, 1,3, Clifford R. Weiss1, Erez Nevo2, Dara L. Kraitchman1, Frank K. Wacker1 1Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States; 2Robin Medical Inc., Baltimore, MD, United States; 3Center for Applied Medical Imaging, Siemens Corporation, Corporate Research, Baltimore, MD, United States Purpose: To test the feasibility and accuracy of a tool that allows for interactive adjustments of the needle plane during a MR guided puncture Method: Experiments were performed in vivo and in phantoms using a gradient based navigation system for real time MR guided punctures in a wide bore MR imager. To assess for accuracy of the system the distance of the needle tip (virtual and real) to the target was determined on MR control scans. Result: The mean 3D total error was 4.9 ±2.8mm in the phantom. The system error was less than 2 mm. In the animal, successful punctures of the target structures could be confirmed in all punctures. Conclusion: The combination of image overlay with real time adjustment of the virtual needle and real-time imaging feedback provides an accurate and intuitive means to perform percutaneous interventions in a wide bore MR imager. 1843. Fast and Precise: Real Time MR-Guided Prostate Biopsy at 3 Tesla in Animal Experiment. Patrik Zamecnik1, Axel j. Krafft2, Florian Maier3, Jaane Rauschenberg2, Michael Bock2 1DKFZ German Cancer Research Center), Heidelberg, Baden-Württemberg, Germany; 2DKFZ (German Cancer Research Center); 3DKFZ (German Cancer Resaerch Center) Real time MR-guided prostate biopsy at 3 Tesla in animal experiment proved to be a fast an precise method to perform prostate biopsies. 1844. Development of a Pneumatic Robot for MRI-Guided Transperineal Prostate Intervention Sang Eun Song1, Nathan Bongjoon Cho1, Iulian Iordachita2, Gregory Scott Fischer3, Junichi Tokuda4, Nobuhito Hata4, Gabor Fichtinger5, Clare Tempany4 1Engineering Research Center, The Johns Hopkins University, Baltimore, MD, United States; 2Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD, United States; 3Mechanical Engineering Department, Worcester Polytechnic Institute, Worchester, MA, United States; 4Brigham and Womens Hospital, Boston, MA, United States; 5School of Computing,, Queens University, Kingston, Ontario, Canada As accurate needle positioning helps the prostate cancer detection and treatment, a number of MRI-compatible robots have been introduced. However, problems exist due to the strong magnetic field and limited workspace. Pneumatic actuator has the minimum distraction in the environment. However, it has poor controllability. To overcome the controllability problem, a simple external damping mechanism that can enhance accuracy was developed. Based on the actuator mechanism and workflow optimized modular design approaches, a new pneumatically actuated 4-DOF parallel robot for MRI-guided prostate intervention was developed. A preliminary evaluation was conducted with satisfying actuator average position error of 0.2mm. 1845. Development and Preliminary Evaluation of a MRI-Guided Transrectal Prostate Intervention Axel Krieger1,2, Sang Eun Song3, Nathan Bongjoon Cho3, Peter Guion4, Iulian Iordachita1, Gabor Fichtinger5, Louis L. Whitcomb1 1Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD, United States; 2Sentinelle Medical Inc., Toronto, Canada; 3Engineering Research Center, The Johns Hopkins University, Baltimore, MD, United States; 4National Institute of Health, Bethesda, MD, United States; 5School of Computing,, Queens University, Kingston, Ontario, Canada This paper reports the design, development and MRI compatibility evaluation of a transrectal prostate robot for MRI-guided intervention. The robot employs an automated needle guide with the goal of increasing needle placement accuracy and reducing interventional procedure times. The design of the robot, employing piezo-ceramic-motor actuated needle guide and manual needle insertion, is reported. Results of a MRI compatibility study show no reduction of MRI image SNR with the motors disabled and a 40% to 60% reduction with the motors enabled. The addition of RF shielding is shown to significantly reduce SNR degradation to the presence of the robotic device. 1846. A Device to Facilitate the Performance of Magic Angle Studies on the Wrist and Elbow Marc Rea1,2, Zion Tsz Ho Tse3, Haytham Elhawary3, Michael Lampérth2, Graeme Bydder4, Ian Young5 1Radiological Sciences Unit, Imperial College London, London, UK, United Kingdom; 2Mechanical Engineering, Imperial College London, London, England, United Kingdom; 3Brigham Womens Hospital, Boston, United States; 4Radiology, University of California San Diego, San Diego, CA, United States; 5Electrical Engineering, Imperial College London, London, United Kingdom A limb-positioning mechanical platform device was developed for remote orientation of the arm to make use of the magic angle effect for imaging tendons. The platform is MR-compatible and actuated by rotary air-driven motors. Clinical trials are imminent. Yue Zhang1,2, Yang Guo2, Ann B. Ragin2, Robert J. Lewandowski2,3, Guang-yu Yang, 3,4, Grace M. Nijm5, Alan V. Sahakian5, Reed A. Omary2,3, Andrew C. Larson2,3 1Bioengineering, University of Illinois at Chicago, Chicago, IL, United States; 2Radiology, Northwestern University, Chicago, IL, United States; 3Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, United States; 4Pathology, Northwestern University, Chicago, IL, United States; 5Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, United States MRI permits immediate depiction of ablated tissue zones for intra-procedural monitoring during irriversible electroporation (IRE) ablation procedures. MRI monitoring offers the potential to permit intra-procedural optimization of IRE procedures to ensure complete ablation of targeted tissue volumes. Yang Guo1, Yue Zhang1,2, Grace Nijm3, Alan Sahakian3, Guang-Yu Yang4, Reed Omary1,5, Andrew Larson1,5 1Department of Radiology, Northwestern University, Chicago, IL, United States; 2Department of Bioengineering , University of Illinois at Chicago, Chicago, IL, United States; 3Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, United States; 4Department of Pathology, Northwestern University, Chicago, IL, United States; 5Department of Biomedical Engineering , Northwestern University, Chicago, IL, United States Electroporation involves targeted delivery of electrical pulses to permeabilize cell membranes, either reversible or irreversible. Irreversible electroporation (IRE), as a new tissue ablation technique, induces tissue necrosis due to permanent cell membrane defects. Assessment of tissue response to IRE may be critical. For our study, we demonstrate that inversion recovery prepared contrast enhancement imaging, with TI adjusted to null the signal intensity from the reversible zone, can visualize the IRE ablated tissue margin (differentiating reversible/irreversible zones) to provide an accurate prediction of ablation. This technique can early detect tissue response to IRE and might be helpful to guide further treatments. Jessica F. Jordao1,2, Carlos A. Ayala-Grosso3,4, Yuexi Huang1, JoAnne McLaurin2, Isabelle Aubert, 2,4, Kullervo Hynynen1,5 1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 2Laboratory Medicine & Pathobiology, University of Toronto, Toronto, ON, Canada; 3Unidad de Biologķa Molecular, Universidad Central de Venezuela, Los Chaguaramos, Venezuela; 4Brain Sciences Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 5Medical Biophysics, University of Toronto, Toronto, ON, Canada The use of antibodies to target toxic amyloid-beta peptides (Aβ) in the brain of Alzheimers patients has shown promise in clinical trials but still faces some difficulties. The blood-brain barrier remains a major obstacle; preventing intravenously delivered antibodies from reaching the brain. In this study, we use transcranial MRI-guided focused ultrasound to efficiently deliver antibodies to the brain of a mouse model of Alzheimers disease and evaluate the efficacy of this treatment. We found that delivery of the antibody is localized to targeted regions and yields a rapid and significant reduction of Aβ plaque load from a single treatment. Johnathan C. Chung1, Robert K. Ryu1, Dingxin Wang2, Richard Tang1, Reed A. Omary2,3, Andrew C. Larson2,3 1Department of Radiology, Northwestern University, Chicago, IL, United States; 2Department of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States; 3Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, United States Four-dimensional (4D) transcatheter intra-arterial perfusion (TRIP) MRI is a monitoring technique that involves targeted intra-arterial (IA) injections of gadolinium (Gd) (<0.001 mmol/kg) to help quantify volumetric tissue-perfusion changes over time. This technique can be used to objectively monitor tumor perfusion changes after UAE in VX2 rabbits. The technique may have future clinical application in optimizing endpoints during UAE. Technical Developments for MR-Guided Interventions Hall B Monday 14:00-16:00 1851. Tuning and Amplification Strategies for Intravascular Imaging Coils Nicolas Yak1, Kevan Anderson2, Graham Wright1,2 1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 2Medical Biophysics, University of Toronto, Toronto, ON, Canada The manufacturing of intravascular imaging coils poses several challenges. Due to their size, it can be difficult to incorporate local matching networks and signal amplifiers. This study investigates tuning and amplification strategies for intravascular coils and to assess the signal-to-noise benefits of incorporating a matching network and/or miniature amplifier into catheter-based intravascular imaging devices at various locations in the signal chain. Results suggest that the use of a LNA close to the receiving coil allows for miniature coax cables to be used despite being noisy. Therefore, designing devices for intravascular applications capable of generating high-SNR images becomes much more feasible. 1852. Three Concepts for Tuning and Matching Intravascular Catheter Coils Celine Pitsaer1, Reiner Umathum1, Ann-Kathrin Homagk1, Cengizhan Ozturk2, Michael Bock1 1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 2Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey Over the past years, the benefit of intravascular coils has been demonstrated providing a local SNR gain in comparison with external coils. Although matching and amplifying directly at the catheter tip could enhance signal quality, it could not be done due to space limitations. In this work we compared three coil concepts that bring matching and preamplifying to the catheter tip. Despite possible limitations due to space restrictions and artefacts from magnetic components, the results show that a significant SNR gain of up to 3 can be achieved with local matching and pre-amplification at the tip of the catheter. 1853. Evaluation of RF Heating of a Multi-Mode Intravascular MRI Coil Peng Wang1, Krishna Kurpad1, Orhan Unal1 1Medical Physics, University of Wisconsin - Madison, Madison, WI, United States Intravascular MRI coils are investigated in our research group to develop a 3D real-time interventional MRI guidance platform with unique imaging and device tip-tracking capabilities. For safety considerations a model is proposed to predict temperature rise in the vicinity of a multimode intravascular coil due to SAR as well as thermal conduction from the heated wire. Numerical simulations are applied to study the current induction, SAR distribution and thermal conduction. The mechanisms for temperature rise around the coil are evaluated and compared for safe interventional MRI operations. 1854. Guidewire Tip Design with Selectively Enabled Magnetic Field Perturbation Wilfred W. Lam1, Charles H. Cunningham1,2 1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; 2Dept. of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada One challenge in the placement of guidewires has been tracking the devices as they are moved within the body. In MR imaging, the marker is a material with a sufficiently large magnetic susceptibility relative to tissue that creates a hypointense region in the surrounding tissue. However, the resulting black hole obscures the region that must be seen. A device is presented which can create a susceptibility marker that can be mechanically turned on and off. Hypointensity in an image of water ahead of the device was only evident when the device was configured to create the marker. Fabio Settecase1, Anthony F. Bernhardt2, Lee Evans2, Vincent Malba2, Alistair J. Martin1, Mark Wilson1, Steven Hetts1 1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States; 2Lawrence Livermore National Laboratory, Livermore, CA, United States Microcoils can be used to steer catheter tips in the interventional MRI setting. Resistive heating due to currents necessary to achieve tip deflections, however, in addition to RF heating of conductive wires, can cause clinically significant temperature increases. This study investigates the use of alumina at the catheter tip to facilitate heat transfer to saline coolant flowing in the catheter lumen to mitigate temperature increases. The use of saline coolant and high heat conductivity material to facilitate heat dissipation are feasible strategies for other microcoil-catheter devices using nonferromagnetic conductive wires designed for interventional MRI. Christina E. Saikus1, Merdim Sonmez1, Israel M. Barbash1, Vincent Wu1, Jamie A. Bell1, Christopher J. Yeung1, Robert J. Lederman1, Ozgur Kocaturk1 1Translational Medicine Branch, Division of Intramural Research, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States Devices for interventional MRI must be evaluated for potential radiofrequency induced heating but phantom heating tests can be difficult to relate to intended uses in vivo. We examined in vivo and post-mortem in situ device heating in swine and more realistic phantom in vitro testing of an actively visualized guidewire for interventional cardiovascular MRI. 1857. An Integrated CMOS Detector for MR Image Guided Interventions Jens Anders1, Paul SanGiorgio1, Giovanni Boero1, Xenia Deligianni2, Sunil Patil2, Klaus Scheffler2 1Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne, Switzerland; 2University of Basel, University Hospital, Basel, Switzerland In this work, standard CMOS technology is used to miniaturize highly integrated active tracking devices in MR image guided interventions. The presented microsystem contains a detection coil, a tuning capacitor, a low-noise amplifier, a downconversion mixer and a low-frequency gain stage on a single integrated circuit. Downconverting the NMR signal to a few kilohertz on chip significantly reduces losses in the cables and thereby facilitates the use of the system in small catheters. The feasibility of the approach is demonstrated with phantom experiments in a standard 1.5 T clinical scanner. Ashvin Kurian George1, Christina E. Saikus1, Ozgur Kocaturk1, Robert J. Lederman1, Anthony Z. Faranesh1 1National Institutes of Health, Bethesda, MD, United States We present a method to remove the ghosting artifact from images formed from under-sampled active device data such as in multi-slice, parallel imaging systems for MR-guided interventions. Ghosting is caused by discontinuities in Fourier space along the phase-encoding direction. The method works by first forming an image from temporally-local, under-sampled Fourier data. This image contains periodically repeated copies in the phase-encoding direction. The non-ghost period of each column is determined by using the view-shared image and exploiting the correlation of the active device image across columns. Gregor Thörmer1, Nikita Garnov1, Jürgen Haase2, Thomas Kahn1, Michael Moche1, Harald Busse1 1Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany; 2Physics and Geosciences Department, Leipzig University, Leipzig, Germany Localization and tracking of devices in a closed-bore scanner may improve the accuracy and workflow of MR-guided interventions and also reduce a potential user bias. The goal was to evaluate the performance of a novel image-based approach for device tracking which is demonstrated in a phantom experiment with a robotically driven needle inside the magnet. The presented method is based on the automatic localization of wireless MR-visible markers in poorly resolved MR images. Integration of the localization algorithm into a custom-made pulse sequence with interleaved anatomical imaging would provide a relatively simple and safe alternative to other tracking approaches. Kun Qing1,2, Li Pan1,3, Barry Fetics4, Frank K. Wacker5, Steffi Valdeig5, Mathew Philip4, Amir Roth4, Erez Nevo4, Dara L. Kraitchman5, Andre J. van der Kouwe6, Christine H. Lorenz1,7 1Center for Applied Medical Imaging, Siemens Corporation, Corporate Research, Baltimore, MD, United States; 2Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 3Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States; 4Robin Medical Inc., Baltimore, MD, United States; 5Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States; 6Department of Radiology, Harvard Medical School, Brookline, MA, United States; 7 Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States The purpose of the present work was to integrate the EndoScout tracking technique into a multi-slice interactive real-time sequence to assist MR guided interventions. The sequence was modified to provide the excitation gradients fed into the Endodoscout system for sensor tracking. The position and orientation of the surgical device is real-time updated and superimposed either on pre-acquired images or real-time images during the procedures. The multi-slice real-time images were displayed to enable both surgical device guidance and underlying tissue monitoring. Animal study suggests that MR guidance using the integrated system is feasible and effective at performing interventional procedures. 1861. Phase Only Cross-Correlation Tracking of a Passive Marker for MR-Guided Interventions Roger Jason Stafford1, Florian Maier2, Axel Joachim Krafft2, Michael Bock2, Axel Winkel3, Kamran Ahrar4 1Department of Imaging Physics, The University of Texas M. D. Anderson Cancer Center , Houston, TX, United States; 2Department of Medical Physics in Radiology, Cancer Research Center Heidelberg (DKFZ), Heidelberg, Germany; 3Invivo GMBH, Schwerin, Germany; 4Department of Diagnostic Radiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, United States Real-time MR-guidance of percutaneous procedures may benefit from methods for automatically adjusting the scan prescription to the needle trajectory, as well as visual delineation of the trajectory, in real-time. In this work, the feasibility of using a phase only cross correlation tracking algorithm for automated identification of a contrast filled needle sleeve with real-time adjustment of the scan prescription for continuous delineation of the needle trajectory during manipulation was investigated in phantom and patients for MR-guidance of percutaneous procedures in a closed bore 1.5T clinical scanner. 1862. Targeted Magnetic Delivery of Cells with an MRI Scanner Johannes Riegler1,2, Jack A. Wells1, Panagiotis Kyrtatos1, Anthony N. Price1, Mark F. Lythgoe1 1Centre for Advanced Biomedical Imaging (CABI), Department of Medicine and Institute of Child Health, University College London (UCL), London, United Kingdom; 2Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), UCL, London, United Kingdom Targeted delivery of cells or drugs is a technique that could increase the efficacy of medical treatments. One possibility for that is using magnetic fields to drag labelled entities to the site of interest. MRI systems are particular interesing for this purpose due to their ability to generate uniform magnetic field gradients across the whole body. We demonstrated the feasibility of steering magnetically labelled cells to one exit tube of a bifurcation phantom by applying MR imaging gradients. This technique could potentially be used for localised cell delivery in the vascular system. 1863. Simultaneous Wireless Fast Scan Cyclic Voltammetry and Amperometry with 3T MRI Kendall Lee1, Jonathan Bledsoe1, Kiaran McGee2, John Huston2, Chris Kimble3, Filippo Agnesi, Kevin Bennet3, Charles Blaha4, Paul Garris5 1Department of Neurosurgery, Mayo Clinic, Rochester, MN, United States; 2Department of Radiology, Mayo Clinic, Rochester, MN, United States; 3Department of Engineering, Mayo Clinic, Rochester, MN, United States; 4Department of Psychology, University of Memphis; 5Biological Sciences, Illinois State University Electroanalytical techniques such as fast-scan cyclic votlammetry (FSCV) and constant-potential amperometry (CPA) have revolutionized neuroscience research by supporting temporally, spatially, and chemically resolved neurotransmitter measurements in the brain. CPA and FSCV were performed by a small, digital-telemetry device called a wireless instantaneous neurotransmitter concentration system (WINCS) specifically developed for neurochemical monitoring. Test measurements were collected during simultaneous 3T imaging using a fast spin echo sequence. WINCS dynamically recorded dopamine electrochemical signatures with sub-second temporal resolution and with high fidelity. We demonstrate proof-of-concept for combining WINCS real-time neurochemical measurements and 3T MRI that may offer simultaneous neurochemical monitoring during fMRI. 1864. Two Channel Interventional Cervix Coil for High Dose Rate Brachytherapy Nikolay Vladimirovic Viskusenko1, Emre Kopanoglu2, John Jezioranski3, Warren Foltz3, Oktay Algin4, Ergin Atalar2 1UMRAM: National Magnetic Resonance Research Center , Bilkent Universty Elektrical and Elektronic Engineering , Ankara , Turkey; 2UMRAM: National Magnetic Resonance Research Center, Bilkent Universty Elektrical and Elektronic Engineering, Ankara, Turkey; 3University Health Network, Toronto, Canada; 4Radiology, Ataturk Hospital, Ankara, Turkey Determination of the diseased tissue region is very crucial for brachytherapy treatment. In this study, we propose a new 2-channel coil structure that is embedded on a commercially available HDRT applicator. After MRI imaging of the cervix, brachytherapy procedure can be carried out as normal without moving the applicator, which is essential for the correctness of radiation dose calculations. In-vivo animal experiments have been conducted and good quality images have been obtained. 1865. Esophagus Imaging with Intraluminal RF Coil for Integrated MR-Endoscope System Yuichiro Matsuoka1, Hayato Yoshinaka1, Susumu Aizawa2, Makiya Matsumoto2, Yoshinori Morita1, Hiromu Kutsumi1, Etsuko Kumamoto3, Kagayaki Kuroda4,5, Takeshi Azuma1 1Graduate School of Medicine, Kobe University, Kobe, Hyogo, Japan; 2Graduate School of Engineering, Kobe University, Kobe, Hyogo, Japan; 3Information Science and Technology Center, Kobe University, Kobe, Hyogo, Japan; 4Medical Device Development Center, Foundation for Biomedical Research and Innovation, Kobe, Hyogo, Japan; 5School of Information Science and Technology, Tokai Univesity, Hiratsuka, Japan An endoscope shows an interior surface image of organ, but it has difficulty finding the information under tissue surface. To assist endoscopy and endoscopic surgery by providing cross-sectional images, we have developed an integrated MR-endoscope system. An intraluminal RF coil to be inserted into esophagus was designed, and MR imaging using this coil and a tracking system to detect the coil position in MRI was conducted using an excised porcine tissue. The layer structure in esophagus could be distinguished in T1- and T2-weighted images. The feasibility of esophagus imaging by the developed coil having high Q value was demonstrated. Cell Tracing Hall B Tuesday 13:30-15:30 Yingli Fu1, Dorota A. Kedziorek1, Steven Shea2, Yibin Xie1, Ronald Ouwerkerk3, Gary Huang1, Tina Ehtiati2, Steffi Valdeig1, Jeff WM Bulte1,4, Frank Wacker1, Dara Kraitchman1 1Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, United States; 2Imaging and Visualization, Siemens Corporate Research, Baltimore, MD, United States; 3National Institute of Diabetes and Digestiv and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States; 4Institute of Cell Engineering, Baltimore, MD, United States To enable allogeneic mesenchymal stem cell therapy for peripheral arterial disease, we present here a novel perfluorootylbromide microcapsues that enhance cell survival and enable cell tracking using noninvasive clinical imaging modalities. 1867. Assessment of Macrophage Depletion on Acute Cardiac Allograft Rejection by MRI Danielle F. Eytan1, T Kevin Hitchens1, Qing Ye1, Yijen L. Wu1, Chien Ho1 1Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States Abundant macrophage infiltration is observed in cardiac allograft rejection, yet their contribution to the rejection process and the tissue damage that results remains unclear. Here we investigated the role these cells play in our rat model of acute cardiac rejection by selectively depleting circulating macrophages using liposomal-clodronate. We used T2*-weighted imaging to detect immune-cell infiltration at sites of rejection by monitoring the accumulation of iron oxide-labeled cells, and cardiac cine-tagging to detect regional myocardial function loss. Our results indicate that macrophages contribute to tissue damage during acute rejection, and that their depletion may attenuate the damaging effects of rejection in rat cardiac allografts.
T. Kevin Hitchens1,2, Parker H. Mills1,2, Lesley M. Foley1, John A. Melick3, Patrick M. Kochanek3,4, Eric T. Ahrens1,2, Chien Ho1,2 1Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States; 2Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States; 3Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States; 4Department of Critical Care Medicine and Anesthesiology, University of Pittsburgh, Pittsburgh, PA, United States Cellular imaging is an important and growing field in magnetic resonance. The ability to non-invasively detect the trafficking and accumulation of cells in vivo has broad implications for both a better understanding of biological processes and the development of novel treatments for numerous conditions. Here explore using post processing techniques called Phase map cross-correlation Detection and Quantification or PDQ for detection and quantification of single MPIO-labeled cells in vivo. PDQ uses phase information to calculate a magnetic dipole moment for each detected cell. This information can be used to correlate labeled cell between serial scans and imaging methods. 1869. MR Imaging of Tumor Initiating Melanoma Cells Sergey Magnitsky1, Alexander Roesch2, Stephen Pickup1, Meenhard Herlyn2, Jerry D. Glickson1 1Radiology, University of Pennsylvanian, Philadelphia, PA, United States; 2Wistar Institute, Philadelphia, PA, United States Melanoma cells were labeled with iron oxide particles and allowed to proliferate. Small iron-retaining sub-cell population with original iron concentration has been detected after 21 days of proliferation. This sub-cell population exhibits high tumorigenicity, self-renewal capacity and drug resistance, and therefore fulfills a definition of tumor initiating cells. After implantation of labeled cells into NOD/SCID mice, iron-retaining cells have been detected by in vivo, ex vivo MRI and Prussian blue staining. Yuxiang Ye1, Thomas C. Basse-Luesekrink1, Paula Arias2, Kai Hu2, Thomas Kampf1, Vladimir Kocoski3, Xavier Helluy1, Peter M. Jakob1,4, Karl-Heinz Hiller1,4, Roland Jahns2, Wolfgang R. Bauer2 1Department for Experimental Physics 5, University of Wuerzburg, Wuerzburg, Bavaria, Germany; 2Deptment of Internal Medicine I, University Hospital Wuerzburg; 3Institute for Virology & Immunobiology, University of Wuerzburg, Germany; 4MRB Research Center, Magnetic-Resonance-Bavaria, Wuerzburg, Germany MR Cell tracking with iron oxide labeling has high sensitivity but could be severely interfered by strong local magnetic susceptibility effects. We show that Fluorine-19 MRI could unambiguously detect blood monocytes/macrophages labeled with perfluorocarbon emulsion infiltrating the haemorrhagic myocardial infarct (MI) core both in vivo and ex vivo in a rat model at 7-T, despite the presence of strong local magnetic susceptibility effects caused by degraded hemoglobin products in microvascular obstruction or haemorrhage, which often occurs after reperfusion therapy . This finding suggests that Fluorine-19 MRI could be a better approach for MR cell tracking in where local T2* effects interfere the detection of magnetically labeled cells. Divya Raman1, Anitha Priya Krishnan2, Scott Kennedy3, John Olschowka4, Sammy N'dive2, Delphine Davis5, Walter G. O'Dell2 1Biomedical Engineering, University of Rochester, Rochester, NY, United States; 2Radiation Oncology, University of Rochester, Rochester, NY, United States; 3Biophysics, University of Rochester, Rochester, NY, United States; 4Neurobiology and Anatomy, University of Rochester, Rochester, NY, United States; 5Imaging Sciences, University of Rochester, Rochester, NY, United States Our hypothesis is that paths of elevated diffusion provide a preferred route for migration of cancer cells away from primary tumor. This can be used to improve radiation treatment of gliomas. Toward this end, we have developed a computational model of cell migration based upon MR-DTI to predict microscopic spread of cancer in patients. Objective of this work is to track MPIO labeled rat glioma cells in rat brain and compare it to rat DTI model and thereby demonstrate that tumor cells migrate farther from the site of engraftment along major fiber tracts compared to gray matter. 1872. SPIO-Labeled Natural Killer Cells: Cytotoxicity and in Vivo Imaging Christiane L. Mallett1,2, Catherine Ramsay1, Paula J. Foster1,2 1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; 2Medical Biophysics, The University of Western Ontario, London, Ontario, Canada Purpose: We labeled natural killer cells and tested cytotoxicity against prostate cancer cells in vitro. In vivo MR tracking was performed. Methods: KHYG-1 cells were labeled with MoldayION by incubation. Toxicity against PC-3M prostate cancer cells was measured after 24 hours co-culture. Labeled KHYG-1 were injected into the flank of mice and tracked with MRI over 9 days. Results: Labeling efficiency (80%) and viability (>90%) were high. Labeled KHYG-1 were toxic to PC-3M. Injected cells were tracked toward the popliteal lymph node in mice. Conclusions: KHYG-1 will be valuable in future in vivo investigations of immuno-therapy of prostate cancer. 1873. Multimodality Imaging of Gene Delivery Via Fluoresecent Iron Oxide Nanoparticles David Peter Cormode1, Gitte Oskov Knudsen1, Amanda Delshad1, Nicole Parker2, Peter Jarzyna1, Torjus Skajaa3, Karen C. Briley-Saebo1, Ronald E. Gordon4, Zahi Adel Fayad1, Savio L C Woo2, Willem J M Mulder1 1Radiology, Mount Sinai School of Medicine, New York, NY, United States; 2Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY, United States; 3Clinical Institute and Dept. of Cardiology, Aarhus University, Skejby, Denmark; 4Pathology, Mount Sinai School of Medicine, New York, NY, United States We have developed a fluorescent iron oxide nanoparticle platform with a gene transfection-enabling polymeric coating. This platform allows gene transfer to be studied via MRI, fluorescence and TEM imaging techniques. We have studied this platform in the setting of liver disease and the effect of varying the polymeric coating by increasing the PEG content from 0-25%. We found that the MRI and fluorescence contrast in the liver was unaffected by the particle coating, however, the cellular distribution was skewed from the Kupffer cells to the therapeutically relevant hepatocytes when the percentage of PEG was increased. Francisco Manuel Martinez-Santiesteban1, Emeline J. Ribot1, Paula J. Foster1, Brian K. Rutt2 1Robarts Research Institute, University of Western Ontario, London, Ontario, Canada; 2Department of Radiology, Stanford University, Palo Alto, CA, United States We present a method that combines the high efficiency of a bSSFP pulse sequence with the image enhancement of susceptibility changes obtained with Susceptibility Weighted Imaging to improve the detection of iron-loaded cells. Benefits of both techniques are achieved with a bSSFP Echo Time larger than the conventional TR/2, increasing the information contained on the phase images. Using the proposed technique, we are able to detect more iron-loaded cells than with bSSFP alone, and the mean fractional signal loss of the detected cells is increased by approximately 20%, improving their visibility and quantification. 1875. On Possible Pitfalls in Working on SPIO Labelled Cells with 2D UTE Sequences Clemens Diwoky1, Andreas Reinisch2, Florian Knoll1, Bernhard Neumayer1, Dirk Strunk2, Rudolf Stollberger1 1Institute of Medical Engineering, Graz University of Technology, Graz, Austria; 2Stem Cell Research Unit, Dept. of Hematology, Univ. Clinic of Internal Medicine, Medical University of Graz, Graz, Austria Within this study we outline some crucial points concerning the use of 2D UTE sequences for the cell detection based on differential images. We show that especially in regions of high iron density many artefacts caused by the pulse sequence yields to misinterpretations or wrong quantitative results. On the basis of an ectopic labelled cell population we discuss the artefacts caused by a common 2D UTE acquisition strategy with half-pulse excitation. Zhi-Feng Xu1, Chong-Yang Shen2, Lin-Ping Wu2, Ye-Yu Xiao, Yao-Wen Chen, Ren-Hua Wu 1medical imging, the 2nd Affiliated Hospital, the Medical College of Shantou University, shantou, guangdong, China; 2Multidisciplinary Research Center of Shantou University, shantou, guangdong, China In this study, we attempt to study the alteration of metabolite of MSCs undergoing adipogenic differentiation to targeted fat cells in vitro, using 9.4T high-resolution 1H NMR spectroscopy.lastly, in our study,several major metabolites can be observed in the MR sepectroscopy that is before and after differentiation of MSCs£¬including choline, creatine, glutamate and myo-inositol, acetate and some fatty acids,etc.Quantification of metabolite concentrations was performed£¬the levels of intracellular metabolites, such as choline, creatine, glumate and acetate all decreased, with the increased level of methionine , succinate and fatty acids after the MSCs differentiation 2 weeks.It indiactes that we can mintor differentiation of MSCs,according the changes of metabolites. 1877. Customizable PLGA-Encapsulated Perfluorocarbon Particles for in Vivo 19F MRI Mangala Srinivas1, Fernando Bonetto1, Luis Javier Cruz1, Arend Heerschap2, Carl Figdor1, I. J.M. de Vries1 1Tumor Immunology, NCMLS, Uni. Radboud, Nijmegen, Gelderland, Netherlands; 2Radiology, Nijmegen Centre for Molecular Life Sciences We present a novel agent for in vivo 19F MRI that is customizable in several parameters including diameter, lifetime, fluorocarbon content, particle charge and coating. The particles can also be covalently bound to targeting agents, dyes, drugs or other moieties, and are stable for long-term storage. We test the particles for labeling primary human dendritic cells for use in cell-based vaccine therapy. The particles can be adapted for use in various experimental systems, as well as clinical use. Geralda A.F. van Tilborg1, Willem J.M. Mulder2, Susanne M.A. van der Pol3, Louis van Bloois4, Annette van der Toorn1, Gert Storm4, Helga E. de Vries3, Rick M. Dijkhuizen1 1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 2Translational and Molecular Imaging Institute, , Mount Sinai School of Medicine, New York, United States; 3Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, Netherlands; 4Department of Pharmaceutics, Institute for Pharmaceutical Sciences, Utrecht, Netherlands In this study we propose a novel lipid-coated fluorescent iron oxide particle for simultaneous magnetic and fluorescent cell labeling. Murine macrophages (RAW) were incubated with the contrast agent and showed efficient labeling without inducing toxicity. Labeled cells were clearly detected with T2-weighted MRI, fluorescence microscopy and flow cytometry. The presented nanoparticulate agent represents a versatile and potent contrast material for cellular imaging, and can be particularly attractive for assessing the fate of in vivo administered labeled cells with multimodal imaging techniques. Sven Gottschalk1, Dįvid Zsolt Balla1, Rolf Pohmann1, Jörn Engelmann1 1High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany Despite of decade-long research, no method exists that could either accurately or non-invasively determine the pancreatic beta-cell mass in vivo. We present in vivo MRI of the mouse pancreas at ultra high fields (16.4T) and the first attempt to visualize pancreatic islets with a newly developed beta-cell specific contrast agent. Structures <100µm and anatomical details of the pancreas were identified. However, the cellular architecture of the pancreas, i.e. the location or amount of islets of Langerhans remains difficult to assess. Using a novel targeted contrast agent in vivo, beta-cell containing islets of Langerhans were identified in an excised pancreas. 1880. Magnetic Resonance Molecular Imaging of Neural Sprouts in Spine Explant Cultures Ingrid E. Chesnick1, Carol B. Fowler1, Yeon Ho Kim2, Helen E. DArceuil3, Jeffrey T. Mason1, Kimberlee Potter1 1Department of Biophysics, Armed Forces Institute of Pathology Annex, Rockville, MD, United States; 2Defense and Veterans Brain Injury Center, Armed Forces Institute of Pathology Annex, Rockville, MD, United States; 3MRVision Co., Redwood City, CA, United States Organotypic slice cultures of spinal cord allow for the study of axonal growth and regeneration, synapse formation, and myelination. Consequently, to better understand the dynamics of spinal cord repair in vivo, this model system was employed as a novel test platform to examine the specificity of actin-targeted Gd-liposomes to actin-rich neural sprouts. Actin-targeted Gd-liposomes were tested on a monolayer of cells and all labeling experiments were confirmed by MRM and fluorescence microscopy. Similar labeling protocols applied to spine explants revealed MR signal enhancement around the neural tube and neural sprouts at the edge of the explants. 1881. Magnetic Resonance Molecular Imaging of Bone Resorbing Osteoclasts Ingrid E. Chesnick1, Carol B. Fowler1, Jeffrey T. Mason1, Kimberlee Potter1 1Department of Biophysics, Armed Forces Institute of Pathology Annex, Rockville, MD, United States The ability to detect osteoclasts on the surface of bone will allow for the development of more sensitive screening tools for monitoring changes in bone metabolism, specifically bone resorption, in response to therapeutic interventions. In this work, we demonstrate the sensitivity of ŃvŅ3-targeted Gd-liposomes to detect low numbers of active osteoclasts in the presence of a mixed population of bone marrow derived cells. Additionally, we present a novel bisphosphonate MR constrast agent for selectively imaging the mineral not subjected to resoption by active osteoclasts. Our approach promises to transform in vivo bone resorption studies. MR Sensors & Reposers Hall B Wednesday 13:30-15:30 1882. SPIO-Alginate Nanoparticles: New Platform for Calcium MR Imaging Amnon Bar-Shir1, Liat Avram1, Smadar Cohen2, Yoram Cohen1 1School of Chemistry, Tel Aviv University, Tel Aviv, Israel; 2Biotechnology Engineering, Ben-Gurion University of the Negev, Beer Sheva, Israel Ca2+ plays an important role in many biological processes. Currently, the imaging technologies that are used for Ca2+ imaging are mostly based on optical methodologies. Based on the facts that alginates polysaccharides can be cross-linked, selectively, with Ca2+ ions and that SPIO aggregation may change the contrast of T2WI, we suggest the SPIO-alginate nanoparticles as "smart" MRI probes for Ca2+ detection. In this study we describe the synthetic procedure of the water-soluble SPIO-alginate nanoparticles and the MRI detectability of different Ca2+ concentrations in variable aqueous solutions (water, serum and culture cell media) at physiological conditions using this nanoparticles-based probe.
1883. New Bullets for PISTOL: Linear and Cyclic Reporter Molecules for 1H MR Oximetry Praveen Kumar Gulaka1, Vikram D. Kodibagkar1,2 1Biomedical Engineering, UT Arlington and UT Southwestern Medical Center at Dallas, Dallas, Tx, United States; 2Radiology, UT Southwestern Medical Center at Dallas, Dallas, Tx, United States The ability to measure tissue oxygen tension non-invasively may have a significant impact in understanding mechanisms of tissue function and in clinical prognosis of disease. Previous research demonstrated hexamethyldisiloxane (HMDSO) as a 1H based pO2 reporter molecule by in vivo spectroscopy and imaging using Proton Imaging of Siloxanes to map Tissue Oxygenation Levels (PISTOL) technique. We now present in vitro data demonstrating the pO2 calibration curves of linear and cyclic siloxanes of different chain lengths as pO2 sensing reporter molecules for use in conjunction with PISTOL. 1884. Hyperpolarized 13C MR Reporter Probe System with Acy-I Gene and [1-13C] N-Acetyl-L-Methionine Albert P. Chen1, Ralph E. Hurd2, Yi-Ping Gu3, David M. Wilson4, Charles H. Cunningham3 1GE Healthcare, Toronto, ON, Canada; 2GE Healthcare, Menlo Park, CA, United States; 3Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 4Radiology, UCSF, San Francisco, CA, United States With the recent development of techniques to achieve highly polarized nuclear spins states via dynamic nuclear polarization and retain the polarization in solution, it may be feasible to utilize a suitable hyperpolarized 13C substrate to target an enzyme reporter gene for non-invasive MR imaging of labeled cells/tissue. In this study, a hyperpolarized 13C MR reporter system is demonstrated in cells transfected to overexpress a reporter gene, aminoacylase I (Acy-I), using pre-polarized [1-13C] N-acetyl-L-methionine as the reporter probe. Carlos J. Perez-Torres1,2, Robia G. Pautler1,2 1Interdepartmental Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, TX, United States; 2Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, United States cFos is a widely utilized marker of neuronal activation that currently requires ex vivo immunohistochemistry for detection. We believe detecting cFos expression in vivo with MRI would provide an unparalleled means to assess neuronal activation in mouse models of human diseases. Importantly, the levels of activation would be a direct measurement of neuronal function. . We have previously described a novel approach to detect Green Fluorescent Protein (GFP) expression in vivo using Magnetization Transfer MRI. Here, we apply the MRI based detection of GFP to evaluate a cFos-GFP fusion model. 1886. Dual 1H and 19F MR LacZ Gene Reporter Molecule Rami Robert Hallac1, Vikram D. Kodibagkar1, Jian-Xin Yu1, Ralph P. Mason1 1Radiology, UT Southwestern Medical Center at Dallas, Dallas, TX, United States The detection of enzyme activity and gene expression in vivo is potentially important for the characterization of diseases and gene therapy. We demonstrate the use of a novel class of dual 1H/19F NMR lacZ gene reporter molecule to identify £]-gal expressing tumors in mice. The substrate shows a single 19F NMR signal and exposure to Ņ-galactosidase induces a large 19F NMR chemical shift response. The combination of Fe3+ and released aglycone product generates intense T2 contrast only in £]-gal expressing tumor. The dual modality approach allows both the detection of substrate and imaging of product. Greetje Vande Velde1, Janaki Raman Rangarajan2, Tom Dresselaers1, Jaan Toelen3, Zeger Debyser3, Veerle Baekelandt3, Uwe Himmelreich1 1Biomedical NMR unit/MoSAIC, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium; 2Medical Imaging Research Center/MoSAIC, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium; 3Molecular Medicine, Katholieke Universiteit Leuven, Leuven, Flanders, Belgium Utilizing lentiviral (LV) and adeno-associated (AAV) viral vector systems for delivering MRI reporter genes (e.g. ferritin) will allow stable labeling and in vivo visualization of marked cells, but their potential limitations for MRI are often insufficiently addressed. LV injection resulted in hypointense contrast at the injection site on T2*-weighted MRI, partially explained by an immune response. Contrasting with LV, AAV injection resulted in little background contrast and AAV-mediated MRI reporter overexpression resulted in significant contrast-to-background on T2*-weighted MRI. We developed an image analysis pipeline that permits to quantitatively compare the hypointense contrast parameters of timeline scans or different experimental groups. Christina H. Liu1, Jia Q. Ren1, Charng-ming Liu1, Philip K. Liu1 1Radiology, Massachusetts General Hospital, Charlestown, MA, United States Synopsis Intracerebroventricular infusion of therapeutics or MR contrast agents by lumbar or cortical puncture to the brains was the route of choice to bypass the blood brain barrier (BBB) and to achieve uniform distribution. However, only limited number of delivery can be performed in the same subject, therefore, has limited longitudinal applicability. Here we explore the feasibility of a non-invasive DNA-based MRI probe delivery route by intraperitoneal injection with BBB bypass to assess gene up-regulation associated with chronic drug exposure. 1889. Remote MR Sensing of PH and Cell Viability Using LipoCEST-Filled Microcapsules Kannie W. Y. Chan1,2, G. Liu1,3, D.R. Arifin1,2, J. W.M. Bulte1,2, M.T. McMahon1,3 1Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 3F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States Cell transplantation is widely used for treatment of various diseases, with cell viability being key for successful therapy. Semi-permeable microcapsules have been used to immunoprotect and visualize cell location, but not cell function. We demonstrate that LipoCEST-filled microcapsules can be used as a novel way to monitor cell viability. CEST contrast is dependent on pH, which in itself is closely related to cell activity and functionality. Our pH-responsive microcapsules showed a significant decrease in CEST signal when cell viability decreased at physiologically relevant pHs, thus representing a useful non-invasive tool to monitor successful cell therapy. Bhumasamudram Jagadish1, Gerald P. Guntle2, Vijay Gokhale3, Amanda F. Baker2, Eugene A. Mash1, Natarajan Raghunand4 1Chemistry, The University of Arizona, Tucson, AZ, United States; 2Cancer Center, The University of Arizona, Tucson, AZ, United States; 3Pharmacology & Toxicology, The University of Arizona, Tucson, AZ, United States; 4Radiology, The University of Arizona, Tucson, AZ, United States DO3A- and DOTA-based thiol complexes of gadolinium have been synthesized and characterized. The molecules are designed to covalently bind the conserved cysteine-34 site in circulating plasma albumin. Redox-sensitivity is conferred by differential relaxivities of the albumin-bound (in oxidizing microenvironments) and unbound (in reducing microenvironments) forms of the complexes. Oxidative stress was induced in tumor-bearing mice by 2-deoxyglucose challenge. The change in tumor T1 following administration of a candidate thiol complex of Gd was significantly lower in treated mice relative to control mice. This is consistent with a 2DG-induced ARE-driven reduction of the tumor microenvironment, and supporting evidence will be presented. 1891. in Vitro and in Vivo Evaluation of GdDO3NI as a Hypoxia Targeting MRI T1 Contrast Agent Vikram D. Kodibagkar1,2, Praveen Kumar Gulaka1, Federico Rojas-Quijano3, Zoltan Kovacs3, Ralph P. Mason, 12, A Dean Sherry2,3 1Biomedical Engineering, UT Arlington and UT Southwestern Medical Center at Dallas, Dallas, Tx, United States; 2Radiology, UT Southwestern Medical Center at Dallas; 3Advanced Imaging Research Center, UT Southwestern Medical Center at Dallas, Dallas, Tx Heterogeneously distributed hypoxic cores in tumors are known to affect radiation sensitivity and promote development of metastases, therefore the ability to image tumor hypoxia in vivo will provide useful prognostic information. Previous research demonstrated that 2-nitroimidazole accumulated in hypoxic tissues due to an enzyme mediated reduction of the nitro group in hypoxic conditions. Here we report the in vitro and in vivo evaluation of a GdDOTA monoamide conjugate of 2-nitroimidazole, GdDO3NI, as a novel hypoxia targeting MRI T1 contrast agent. 1892. In Vivo Detection of the Metabolism of Novel Hypoxia Probes in Models of Glioma by 1H NMR Jesus Pacheco-Torres1,2, Rocio Pérez-Carro1, Paloma Ballesteros2, Pilar Lopez-Larrubia1, Sebastian Cerdan1 1Instituto de Investigaciones Biomédicas "Alberto Sols" - CSIC, Madrid, Spain; 2Laboratory of Organic Synthesis and Molecular Imaging, UNED, Madrid, Spain We propose a novel protocol to evaluate tumor hypoxia in vivo by monitoring the reduction of intratumoral nitromidazolil probes using PRESS spectroscopy. We injected C6 tumors implanted in the flank of nude mice with a solution containing a mixture of the oxygen sensitive probe misonidazole and TSP, an oxygen insensitive probe. It is shown that the rate of disappearance of injected misonidazole depended on the intratumoral local oxygen tension in vivo, as modified by air or oxygen breathing. In contrast, the rate of disappearance of the TSP reference remained independent of the same changes in local oxygen tension. Seung Hong Choi1, Hye Rim Cho2, Hyeonjin Kim3, Hoe Suk Kim2, Woo Kyung Moon2 1Radiology, Seoul National University, Seoul, ., Korea, Republic of; 2Seoul National University Hospital, Korea, Republic of; 3Gacheon Univeristy of Medicine and science, Korea, Republic of This study shows the possibility of noninvasive assessement of lymph node metastasis of cancer cells using MR reporter gene of ferritin. In addition, MR imaging seems to be superior to optical imaging in the evaluation of deep organ metastasis of cancer cells. Eliana Gianolio1, Jebasingh Bhagavath Singh1, Markus Aswendt2, Francesca Arena1, Alessandro Barge3, Mathias Hoehn2, Silvio Aime1 1Chemistry IFM and Molecular Imaging Center, University of Torino, Torino, TO, Italy; 2In-vivo-NMR Laboratory, Max Planck Institute for Neurological Research, Cologne, Germany; 3Department of Drug Science and Technology, University of Torino, Torino, Italy We report about the synthesis and the characterization of a Gd-DOTAgal derivative that has been proven to be a good ā-galactosidase expression reporter. It consists in a system that can undergo polymerization in the presence of Tyrosinase upon beta-gal activated cleavage of the tyr-gal bond. Novel Imaging Agents Hall B Thursday 13:30-15:30 1895. Solution, Cell and Animal Studies in Molecular MRI of Estrogen Receptor α Adi Pais1, Chidambaram Gunanathan1, Inbal Biton1, Raanan Margalit1, David Milstein1, Hadassa Degani1 1Weizmann Institute of Science, Rehovot, Israel We have develop a non-invasive molecular MRI method for detecting, and investigating the level, activity and degradation of estrogen receptor alpha (ER) in breast cancer cells, tumors and metastases. Two novel contrast agents, composed of a gadolinuim-pyridiniumtetraacetic acid conjugated to 17ā-estradiol or to tamoxifen were synthesized and characterized for their solution chemistry as well as their biological activity and MRI parameters in cells and tumors. These agents demonstrated selective binding with high affinity to ER and significant enhancement of the water T1 and T2 relaxivity in ER+ as compared to ER- systems, and served to identify ER localization in vivo. Todd C. Soesbe1, Navin Bansal2, Ananth V. Annapragada3, Ketan B. Ghaghada3, Zoltan Kovacs1, A. Dean Sherry1,4 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Department of Radiology, Indiana University School of Medicine, Indianapolis, IN, United States; 3School of Health Information Sciences, The University of Texas at Houston, Houston, TX, United States; 4Department of Chemistry, The University of Texas at Dallas, Dallas, TX, United States Liposomal delivery of MR contrast agents offers improved steady-state imaging and signal-to-noise due to their long blood circulation life-time. Also, the relative small size of the liposomes (”Ö 100 nm in diameter) allows them to have direct uptake in certain tumor lines that exhibit "leaky" vasculature (e.g. MBA-MD-231 breast cancer cells). The 1H methyl group of TmDOTMA has a chemical shift that is about -100 ppm away from bulk water. This TmDOTMA peak can be imaged using chemical shift selective (CHESS) techniques in which the water signal is completely absent. By using this method we can obtain "waterless" MR images where the only signal is due to the TmDOTMA filled liposomes. This is analogous to images obtained in nuclear medicine where the only signal is from the radioactive isotope. Liposomal TmDOTMA imaging has the potential to produce high resolution MR angiograms and molecular targeted images that are not contaminated by the bulk water signal. We explored this hypothesis by injecting a 5.8 mM solution of TmDOTMA liposomes, both intravenously and intratumorally, into a tumor-bearing mouse. 1897. Gadoxane a Novel Degradable Silsesquioxane Based Macromolecular MRI Contrast Agent Joern Engelmann1, Joerg Henig2, Sven Gottschalk1, Hermann A. Mayer2 1High Field MR Center, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany; 2Institute for Inorganic Chemistry, University of Tuebingen, Tuebingen, Germany Silsesquioxane-based macromolecular MRI-contrast agents have recently been reported to have a compact globular structure resulting in significantly higher relaxivities when compared to smaller MRI-probes. The stability of the core under physiological conditions is unknown so far. We therefore studied the stability of Gadoxane, a new silsesquioxane-based contrast agent connected to eight DOTAGA-gadolinium chelates. The silsesquioxane core was almost completely hydrolyzed under physiological conditions while the integrity of the gadolinium chelate was maintained. In conclusion, these probes cannot be considered as stable anymore. However, their degradability might improve their in vivo-applicability due to a faster renal excretion of the smaller fragments. 1898. Targeting Sentinel Lymph Nodes with Macrophages Labeled with FIONs on 1.5 T MR Imaging Seung Hong Choi1, Hye Rim Cho2, Nohyun Lee3, Taeghwan Hyeon4, Woo Kyung Moon2, Chul-Ho Sohn1 1Radiology, Seoul National University, Seoul, ., Korea, Republic of; 2Seoul National University Hospital, Korea, Republic of; 3School of Chemical and Biological Engineering, Seoul National University, Seoul, Korea, Republic of; 4School of Chemical and Biological Engineering, Seoul National University, Korea, Republic of The purpose of the present study was to confirm if metastatic lymph nodes can be targeted by macrophages labeled FIONs by using a mouse melanoma model. Francisco Perez-Balderas1, Benjamin G. Davis2, Sander van Kasteren2, Alexandr Khrapichev1, Daniel Anthony3, Nicola R. Sibson1 1CR-UK/MRC Gray Institute for Radiation Oncology and Biology, University of Oxford, Oxford, United Kingdom; 2Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom; 3Department of Pharmacology, Univerity of Oxford, Oxford, United Kingdom Biodegradable multimeric iron oxide microparticles were obtained by conjugation of iron oxide nanoparticles through peptides. These multimeric particles constitute an ideal platform for new highly sensitive and specific MRI contrast agents. Chalermchai Khemtong1, Osamu Togao2, Jimin Ren2, Chase W. Kessinger1, Masaya Takahashi2, A Dean Sherry2, Jinming Gao1 1Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States Herein, we report the effect of PEG corona lengths on MR relaxivity and ORS sensitivity of SPPM. Results showed that the length of the pegylated shell is a critical physical parameter that controls MR relaxivity and ORS sensitivity of SPPM. SPPM with shorter PEG corona has a higher T2 relaxivity and hence ORS sensitivity. Results from this study provide the fundamental insights on the design of SPPM as ultrasensitive MRI nanoprobes for in vivo molecular imaging applications. 1901. Enhancing the Relaxivity of Gd-Based Liposomes and Micelles by Restricting the Local Motions Mauro Botta1, Filip Kielar1, Lorenzo Tei1, Enzo Terreno2 1Environmental and Life Sciences, Universita' del Piemonte Orientale, Alessandria, Italy; 2Center for Molecular Imaging, Department of Chemistry IFM, University of Turin, Turin, Italy A novel GdDOTA derivative was prepared featuring two adjacent glutamic acid moieties. Reaction with dodecyl amine yields an amphiphilic complex that maintains the favorable properties of the parent complex in terms of stability, relaxivity and water exchange rate. The self-assembling process in aqueous solution results in micelles and liposomes of enhanced relaxivity (+ 140 % at 0.47 T; + 100 % at 1.5 T) over that of corresponding single-chain systems that is explained in terms of a strong limitation of the local rotation about the hydrophobic chains. 1902. New Window on Human Cognition: 13C Assays of Glutamate Neurotransmission in Frontal Brain Napapon Sailasuta1, Thao T. Tran1,2, Brian D. Ross1,2 1Huntington Medical Research Institutes, Pasadena, CA, United States; 2Rudi Schulte Research Institute, Santa Barbara , CA, United States Cognitive function in humans is currently imaged in real time only with radioactive PET or with task-driven fMRI. True molecular imaging on the underlying neurochemical events, here ascribed predominantly to glutamate neurotransmission, has been developed using non-radioactive, stable carbon isotopes infused intravenously and selectively taken up and metabolized by EITHER neurons or glia, in frontal brain (a totally novel application relevant to imaging of cognition) and in posterior brain. The tests have been evaluated in more than 20 normal human subjects and several prototypical disorders of cognition with promising results which complement or replace PET. 1903. Biodegradable MPIO and SPIO Using FDA Approved Polymers Michael K. Nkansah1, Durga Thakral1, Erik M. Shapiro, 12 1Department of Biomedical Engineering, Yale University, New Haven, CT, United States; 2Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, United States Magnetic cell labeling has primarily been accomplished using dextran-coated iron-oxide nanoparticles. A drawback to their use is the low iron content per particle, coupled with cessation of commercial production. As an alternative, micron-sized iron-oxide particles (MPIOs) have been used, the benefits of which are that they contain ~ 30% iron. The downside is that MPIOs are composed of inert, non-degradable and not FDA-approved polymers, potentially limiting clinical utility. Here we demonstrate the fabrication of fluorescent, biodegradable MPIOs, composed of PLGA and cellulose, two FDA-approved polymers. These particles have high relaxivity and are capable of labeling cells for MRI-based cell tracking. 1904. Nitroxide Compound CPTO-EG as an MRI Contrast Agent Andrew Nencka1, Xiping Liu1, Joy Jeseph1, Shi-Jiang Li1, Balaraman Kalyanaraman1 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States The conventional T1 contrast agent, gadolinium-DTPA complex, does not cross the blood brain barrier (BBB) in the absence of injury or tumor. Nitroxides possess a single unpaired electron but generally do not cross the BBB. The compound we developed can cross the BBB and provide MRI contrast in brain imaging by shortening the longitudinal relaxation time (T1) of water protons (1). Present study reports the progress of the development of a contrast agent, 2,2,5,5- tetramethylpyrroline 1-oxide 3-ethyleneglycolcarboxylate (CTPO-EG), which can cross the BBB and has significantly greater relaxivity. Hisanori Kosuge1, Toshiro Kitagawa1, Takeshi Kobayashi2, Michael V. McConnell1 1Cardiovascular Medicine, Stanford University, Stanford, CA, United States; 2Biological Chemistry, Chubu University, Kasugai, Aichi, Japan Inflammation plays a critical role in the progression of atherosclerosis. Magnetite liposomes (MLs) have been used for magnetic hyperthermia of cancer cells and for cellular MR imaging. Thus, they may have the potential to both image and treat vascular inflammatory cells. We demonstrate that MLs show macrophage uptake and effective magnetic hyperthermia and cell death in vitro. ML also imaged mouse carotid vascular inflammation by 7T MRI. Hee-Kyung Kim1, Nasiruzzaman Sk Md2, Ji-Ae Park3, Seung-Tae Woo4, Tae-Jung Kim5, Yongmin Chang1,6 1Department of Medical & Biological Engineering, Kyungpook National University, Daegu, Korea, Republic of; 2Advanced Research Institute for Recovery of Human Sensitibiliy, Daegu, Korea, Republic of; 3Korea Institute of Radiological & Medical Science, Seoul, Korea, Republic of; 4Bayer Schering Pharma Korea, Seoul, Korea, Republic of; 5Department of Applied Chemistry, Kyungpook National University, Daegu, Korea, Republic of; 6Department of Diagnostic Radiology and Molecular Medicine, Kyungpook National university, Daegu, Korea, Republic of We report the synthesis of 1,1-ferrocendiylamines (L) and their Gd(III) complexes of the type [Gd(L)(H2O)], referred to as Ferromides, as a new family of BPCAs. Also reported is the investigation of their thermodynamic and magnetic resonance properties along with in vitro and in vivo MR studies. They all exhibit greater thermodynamic stability (ie., logKsel) than their acyclic and cyclic analogues such as DTPA-BMA, DTPA, and DOTA and compare favorably to MS-325, a well-known BPCA. The R1 relaxivities of Ferromides are quite high as compared with other MRI CAs currently in use. In the case of Ferromide-1, for instance, the R1 relaxivity is 7.5 mM1sec1, which is twice as high as that of structurally related Dotarem® (R1=3.6 mM1sec1). The R1 relaxivity is further increased in an aqueous saline solution of HSA (4.5% w/v) to be compared quite favorably to that of MS-325, and most strikingly, the increase is observed even in the absence of the electrostatic phosphate-HSA interaction. The in vivo MR images of mice obtained with Ferromide-1 show the contrast enhancement not only in heart and bladder but also in abdominal aorta, clearly demonstrating the blood-pool effect. 1907. Mn-Loaded Apoferritin: A High Sensitivity, Biologically Compatible MRI Agent. Simonetta Geninatti-Crich1, Ferenc Kalman1, Ibolya Szabo1, Stefania Lanzardo1, Juan Carlos Cutrin1, Laura Conti1, Silvio Aime1 1University of Torino, Torino, Italy An innovative approach to the design of MRI Contrast Agents has been pursued through the entrapment of Mn(II) aqua ions inside the inner cavity of Apoferritin. This imaging probe can be proposed in the diagnosis of a variety of liver diseases involving an alteration in the hepatic iron storing capabilities (e.g. hepatocellular carcinoma, fibrosis, cirrhosis). Gin-Chung Liu1,2, Dayananda Kasala3, Tsung-Sheng Lin3, Chiao-Yun Chen1,4, Twei-Shiun Jaw1,2, Yu-Ting Kuo1,2, Yun-Ming Wang3 1Department of Medical Imaging, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; 2Department of Radiology,Faculty of Medicine,College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; 3Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan; 4Department of Radiology,Faculty of Medicine,College of Medicine, Kaohsiung Medical University, Kaohsiung , Taiwan In this study, we have developed a new contrast agent [Gd(Try-TTDA)] 2- that can recognize Cu2+ ion in the living cells. In addition, the Gd3+ complex attributes excellent selectivity for Cu2+ over a choice of other metal ions. A gradual increases in the relaxivity and signal intensity of ex vitro and in vitro MR imaging upon Cu2+ detection. These results implicate that a new MR based contrast agent [Gd(Try-TTDA)])] 2- can serve as a Cu2+ sensor using relaxometry and MR imaging 1909. In Vivo quantification of SPIO Nanoparticles with Phase Gradient Mapping Jason A. Langley1, E Kay Jordan2, Wei Liu3, Joseph A. Frank2, Qun Zhao1 1Department of Physics and Astronomy, The University of Georgia, Athens, GA, United States; 2Experimental Neuroimaging Section, Laboratory of Diagnostic Radiology Research, National Institutes of Health, Bethesda, MD, United States; 3Phillips Research, North America, Briarcliff Manor, NY, United States A method for quantifying concentrations of SPIO nanoparticles is presented in this abstract and the proposed method is tested on SPIO-labeled tumors that were implanted in the flank of nude mice. Each voxel within the tumor was modeled as a homogeneous sphere with magnetization m. The magnetic field gradient from each voxel was then superimposed to form the theoretical magnetic field gradient of the tumor, which was then fitted to the gradient of the experimental field map, measured by the acquired phase maps. The results from the x-component of the phase gradient accord well with the known SPIO concentrations. Tungte Wang1,2, Martin Hossann1,2, Michael Peller3, Maximilian Reiser3, Rolf Dieter Issels1,2, Lars Hans Lindner1,2 1Department of Internal Medicine III, University Hospital, Grosshadern, Munich, Bavaria, Germany; 2CCG Hyperthermia, Institute of Molecular Immunology, Helmholtz Center Munich German Research Center for Environmental Health, Munich, Bavaria, Germany; 3Department of Clinical Radiology, University Hospital, Grosshadern, Munich, Bavaria, Germany Phosphatidylglyceroglycerol (DPPGOG)-based thermosensitive liposomes (TSL) with encapsulated proton MR Gd-based T1 contrast agent (CA) have been proposed for noninvasive MR thermometry during tumor treatment using chemothermotherapy. In this work, the DPPGOG-TSL with four separately encapsulated Gd-based CAs which have diverse chemical structures were studied in vitro by measuring the temperature dependence of their T1 while heated from 30 to 50 °C. The measurements revealed that the release of macrocyclic nonionic Gd-based CA from the DPPGOG-TSL resulted in the most percent T1 decrease and thus the DPPGOG-TSL with such encapsulated CA has the potential for the optimal T1 enhancement effect. 1911. Porous Mn2+ - Fe3O4 Nanoparticles with High T1 and T2 Relaxivity Veronica Clavijo Jordan1, Michael R. Caplan1, Kevin M. Bennett1 1Bioengineering, Arizona State University, Tempe, AZ, United States We report a protein based nanoparticle with a Fe3O4 crystal core and Mn2+ bound to surface channels. The metal core size ranged from 3 to 6nm in diameter, and ICP results indicate 7 Mn2+ per protein. HRTEM shows that the core metal is magnetite with a lattice spacing of 0.25nm. Following the proposed synthesis, we suspect that the high per-ion T1 (338mM-1s-1) and T2 (133 mM-1s-1) relaxivity are due to a cooperative effect contributed by the Mn2+ and the Fe3O4 crystal. MRI scans of rat brain inoculations show it can be detected in vivo. Benjamin Marty1, Julien Flament1, Céline Giraudeau1, Caroline Robic2, Marc Port2, Franck Lethimonnier1, Fawzi Boumezbeur1, Julien Valette1, Denis Le Bihan1, Sébastien Mériaux1 1CEA/DSV/I2BM/Neurospin, Gif-Sur-Yvette, France; 2Research Division, Guerbet, Roissy-Charles de Gaulle, France Gadolinium-based contrast agents (Gd-based CA) have been used for many years for various MRI applications including MR-based molecular imaging with targeted compounds. One of the most important factors to consider for brain applications is the diffusivity of these probes through the cerebral tissue to their target. This study proposes a methodology allowing quantification of Gd-based CA concentration by acquiring dynamic T1 maps. This approach has been applied to estimate in vivo in the rat brain the apparent diffusion coefficient of five compounds with different hydrodynamic diameters opening the way to a better understanding of diffusion mechanisms of supra-molecular imaging probes. 1913. Novel Nanoparticle Formulations with Enhanced 19F Relaxation Anke De Vries1, Muhammed Yildirim2, Sander Langereis2, Rolf Lamerichs2, Klaas Nicolay1, Holger Gruell, 12 1Biomedical NMR, Faculty of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 2Philips Research, Eindhoven, Netherlands Nanoparticle formulations incorporating Gd(III) complexes in the surfactant layer increases the longitudinal relaxation rate more than two-fold, resulting in a substantial sensitivity gain. 1914. Fluorinated Lanthanide (III) Probes for 19F Magnetic Resonance Imaging. Ian Wilson1,2, Gilberto S. Almeida1,2, Andrew M. Blamire2, Kirsten H. Chalmers3, David Parker3, Ross J. Maxwell1,2 1Northern Institute of Cancer Research, Newcastle University, Newcastle Upon Tyne, Tyne and Wear, United Kingdom; 2Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle Upon Tyne, Tyne and Wear, United Kingdom; 3Department of Chemistry, Durham University, Durham, United Kingdom New cancer treatments are being developed against specific molecular targets, but imaging methods are required to demonstrate drug-target interaction. Fluorinated 19F MR probes are of great interest due to their sensitivity, large chemical shift and minimal endogenous signal. This study evaluates novel fluorinated lanthanide probes in vitro and in vivo. Relaxation results show 100-fold reduction in T1 corresponding to an improvement in signal:noise per unit time of about 10-fold. In vivo results showed limited tumour uptake of the diamide complex, L4Gd, compared to gadoteridol. This strategy is useful for pharmacokinetic evaluation of fluorinated lanthanide complexes. Ying-Hsiu Lin1, Gin-Chung Liu2,3, Twei-Shiun Jaw2,3, Yu-Ting Kuo2,3, Chiao-Yun Chen2,3, Yun-Ming Wang1 1Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan; 2Department of Medical Imaging, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; 3Department of Radiology,Faculty of Medicine,College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan This study describes the synthesis and biologic evaluation of a IL11 peptide targeted dual-labeled imaging agent as a potential probe for detecting human breast cancer. The IL11 peptide substrate was synthesized and conjugated with the TTDA chelating moiety and cy5.5 via solid-phase peptide synthesis. The results of in vitro optical and MR imaging indicated that the targeted contrast agent specifically targeted to human breast cancer cell and lead to significant enhancement. The preliminary results also demonstrated that the bimodal IL-11 peptide analog could be used to detect IL-11Rα positive breast cancer with MRI and fluorescence microscope at the cellular level. 1916. A Dual Modality Nanoparticle MRI/CT Contrast Agent with Enhanced T1 and T2 Relaxivity Simon A. Lubek1, Veronica Clavijo Jordan1, Kevin M. Bennett1 1Bioengineering, Arizona State University, Tempe, AZ, United States We report a dual MRI/CT protein based W-Fe nanoparticle contrast agent with high T1 (4,497 mM-1s-1) and T2 (458,143 mM-1s-1) per particle relaxivities. The T1 relaxivities observed demonstrated a 58 fold increase over iron oxide particles. TEM results showed nanoparticles ranging from 9 to 13nm in diameter. Rat striatum MRI scans demonstrated the agent is detectable in vivo. Furthermore, a CT comparison demonstrated a 1.5 fold contrast increase as compared to iron oxide particles. Lingzhi Hu1, Lei Zhang1, Junjie Chen1, Gregory M. Lanza1, Samuel A. Wickline1 1Washington University School of Medicine, St. Louis, MO, United States Acquisition parameters for in vivo 19F MR quantification of administrated PFC nanoparticle (NP) have been optimized, in the sense of minimizing the oxygenation effect and maximizing the SNR. Bloch equation based simulation has been performed to simulate the acquired intensity of perfluoro-15-crown-5-ether NP under normoxia and hyperoxia condition. Subsequently, in vivo 19F MR imaging, T1 measurement and 19F quantification have been carried out on C57BL/6 mouse under normoxia and hyperoxia respectively. Both simulation and experiment have validated (1) the optimal TR for achieving high is 1.5*T1; (2) the quantification is insensitive to oxygen level given TR≥ 3* T1. 1918. Multimeric Gd-Based Contrast Agents for High Field MR-Imaging Lorenzo Tei1, Giuseppe Gugliotta1, Mauro Botta1 1Dipartimento di Scienze dell'Ambiente e della Vita, Universitą del Piemonte Orientale "A. Avogadro", Alessandria, Italy New T1 agents that would take advantage of current 1.5 3 T scanners showing excellent relaxation properties over a broad range of imaging field strengths are object of intense research. Multimeric GdIII agents with medium molecular weight (~3-4 KDa) exhibit improved relaxivity values also at high fields. GdIII di-, tri-, tetra-, hexa- and octameric complexes based on stable and efficient Gd-AAZTA derivatives were synthesised. 1H relaxivity data as a function of magnetic field strength and temperature as well as T1-weighted phantom MR-images at different fields were acquired. These multimeric GdIII contrast agents exhibit improved efficiency for application in both clinical MRI and Molecular Imaging protocols. 1919. 3D δR2 Microscopy MRA with a New Blood Pool Contrast Agent: A Comparison with Resovist® Chien-Yuan Lin1, Si-Han Wu2, Ming-Huang Lin1, Yann Hung2, Chung-Yuan Mou2, Chen Chang1 1Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan; 2Department of Chemistry, National Taiwan University, Taipei, Taiwan We have recently developed a new blood pool contrast agent (Fe3O4@SiO2/PEG) which possesses higher transverse relaxivity and long intravascular half-life. This study was aimed to assess the ability of Fe3O4@SiO2/PEG to improve high-resolution magnetic resonance angiography in visualizing cerebral microvasculature. 1920. Improving T1-Weighted "Hot Spot" Imaging with Colloidal Iron Oxide Nanoparticles Shelton D. Caruthers1, Angana Senpan1, Dipanjan Pan1, Grace Hu1, Samuel A. Wickline1, Gregory M. Lanza1 1C-TRAIN, Washington University, St. Louis, MO, United States Iron oxide nanoparticles have been extensively used for nontargeted and targeted imaging applications based upon highly sensitive T2* imaging properties, which typically result in negative contrast effects. Colloidal Iron Oxide Nanoparticles offer both traditional T2* detection and T1 weighted "hot spot" detection. This work explores the mechanisms for improving this T1 detectability. 1921. Lanthanide Trifluoride Nanoparticles for Dynamic Contrast Enhanced MRI Wendy Oakden1, Evelyn Ning Man Cheung2, R Scott Prosser, 2,3, Greg Jan Stanisz1,4 1Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; 2Department of Biochemistry, University of Toronto, Toronto, ON, Canada; 3Department of Chemistry, University of Toronto, Toronto, ON, Canada; 4Imaging Research, Sunnybrook Health Science Centre, Toronto, ON, Canada We present a new class gadolinium-based contrast agents for MR imaging. The contrast agent consists of nanoparticles with a lanthanide fluoride core (Gadolinium and Cerium trifluoride) surrounded by a coating of polyacrilic acid. Chemical similarity between different lanthanide-series elements allows core elements to be varied, altering size and relaxivity as well as rendering the nanoparticles visible under fluorescence microscopy via the addition of Europium or Terbium. The polyacrilic acid coating can be functionalized to allow for cellular uptake. This flexible contrast agent has been successfully used in vivo for dynamic contrast enhanced MR imaging. 1922. Enhanced Targeted MRI Contrast Using Silica Coated Magnetite Nanoparticles Jyoti Lodhia1, Dodie Pouniotis2, Giovanni Mandarano1, Peter Eu, 1,3, Simon Cowell1 1Medical Radiations Research Group, School of Medical Sciences, RMIT University, Melbourne, Victoria, Australia; 2Cancer and Tissue Repair Research Group, School of Medical Sciences, RMIT University, Melbourne, Victoria, Australia; 3Centre for Molecular Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia MRI is a high spatial resolution non-invasive technique but it has low specificity for targeting explicit pathologies. To achieve a more targeted delivery an MRI contrast agent must be biocompatible, have high chemical stability, be easily functionalised and retain a high net magnetisation value.This study using a highly efficient biocompatible iron oxide nanoparticle with well defined magnetic properties (80emu/g and a T2 of 235.5 mmol-1l s-1) was able to specifically target and image a cancer. The results demonstrated the potential for targeted iron oxide silica nanoparticles in the MRI of specific pathologies. Lindsay Kathleen Hill1, Talha S. Siddiqui2, Dung Minh Hoang1, Susan Pun1, Marc Anton Walters2, Youssef Zaim Wadghiri1 1Radiology, NYU School of Medicine, New York, United States; 2Chemistry, New York University, New York, United States In the research described here we designed a new silver multimodal nanoparticle containing GdDTPA and tested the effect of coligated polyethyleneglycol (PEG) chains on particle distribution, clearance and contrast enhancement. The resulting GdDTPA content, relaxivity and solubility were characterized in vitro and their biodistribution was assessed by abdominal MRI. Molecular Imaging TN Disease Models Hall B Monday 13:30-15:30 1924. Early Detection of Brain Metastasis Using Novel MRI Contrast Agent Targeting VCAM-1 Sebastien Serres1, Lukxmi Balathasan, Thomas Weissensteiner, Shawn W. Carbonell, Martina A. McAteer2, Robin P. Choudhury2, Daniel C. Anthony3, Ruth Muschel, Nicola R. Sibson 1Gray Institute for Radiation Oncology and Biology, University of Oxford, Oxford, Oxon, United Kingdom; 2Department of Cardiovascular Medicine, University of Oxford; 3Department of Pharmacology, University of Oxford Early detection of brain metastasis using novel MRI contrast agent targeting VCAM-1 Sebastien Serres1, Silvy Mardiguian2, Martina A. McAteer3, Robin P. Choudhury4, Sandra J. Campbell5, Paul Smith6, Fay Saunders7, Nicola R. Sibson8, Daniel C. Anthony2 1Gray Institute for Radiation Oncology and Biology, Oxford, Oxon, United Kingdom; 2Department of Pharmacology, University of Oxford; 3Department of Cardiovascular Medicine; 4Department of Cardiovascular Medicine, University of Oxford; 5Department of Pharmacology, university of Oxford; 6Department of Pharmacology, UCB, Slough; 7Department of Antibody Biology, UCB, Slough,; 8Gray Institute for Radiation Oncology and Biology, University of Oxford Anti-IL17 treatment reduces clinical score and VCAM-1 expression in EAE-ABH mice detected by in vivo magnetic resonance imaging Nivedita Naresh1, Moriel Vandsburger1, Alexander Klibanov, 12, Patrick Antkowiak1, Yaqin Xu1, Brent A. French1,3, Frederick H. Epstein1,3 1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 2Division of Cardiovascular Medicine, University of Virginia; 3Department of Radiology, University of Virginia Macrophages play the critical role of clearing necrotic debris in the wound healing response that follows myocardial infarction (MI). Two days after MI, we labeled macrophages in vivo using intravenous liposomes containing gadolinium. On day 5 after MI, cardiorespiratory-gated (CRG) Look-Locker MRI of the heart quantified T1 shortening of the infarct zone secondary to infiltration of the labeled macrophages. The T1 shortening effect was dependent upon the dose of liposomes. Macrophage labeling with Gd-liposomes and T1-mapping with CRG Look-Locker imaging may prove useful for quantitative MRI of post-MI macrophage infiltration in preclinical murine studies. Carmen Burtea1, Sophie Laurent1, Eric Lancelot2, Olivier Rousseaux2, Sébastien Ballet2, Coralie Thirifays1, Marc Port2, Gérard Toubeau3, Luce Vander Elst1, Claire Corot2, Robert Nicolas Muller1 1General, Organic and Biomedical Chemistry, NMR and Molecular Imaging Laboratory, University of Mons, Mons, Belgium; 2Research Center, Guerbet, Aulnay-sous-Bois, France; 3Laboratory of Histology, University of Mons, Mons, Belgium A VCAM-1-targeted cyclic heptapeptide peptide was conjugated to USPIO (USPIO-R832), and VCAM-1 binding was first confirmed on HUVEC stimulated with TNF-alpha. Subsequently, USPIO-R832 was evaluated by MRI at 4.7T on ApoE-KO mice, by using T2 and T2*-weighted imaging sequences. The ability to bind to atherosclerotic plaque of this molecular imaging probe was furthermore corroborated by histochemistry. The control imaging probe was represented by USPIO vectorized by a non-specific peptide (USPIO-NSP). Marcus R. Makowski1, Gopal Varma, Christian Jansen, Andrea J. Wiethoff, Tobias Schaeffter, Mathias Taupitz2, Rene M. Botnar 1Kings College London, Division of Imaging Sciences, , London, United Kingdom; 2Radiology, Charite , Berlin, Germany Macrophages have been identified as a contributor to plaque instability in atherosclerosis. The aim of this study was to noninvasively assess iron oxide uptake at different stages of plaque development in the innominate artery of apoE-/- mice and to evaluate the effect of anti-inflammatory treatment using T2* weighted and positive contrast susceptibility gradient mapping (SGM) MRI. Molecular alterations in plaque composition with regard to macrophage content could be detected using iron oxide particles in combination with T2* weighted and SGM MRI. Anti-inflammatory treatment with statins resulted in a smaller SGM signal and smaller signal voids on T2* weighted images. Jochen Keupp1, Anne H. Schmieder2, Samuel A. Wickline2, Gregory M. Lanza2, Shelton D. Caruthers2 1Philips Research Europe, Hamburg, Germany; 2C-TRAIN, Washington University, St. Louis, MO, United States Patient stratification using molecular MRI of angiogenesis could change standard of care in anti-angiogenic therapy. Previously, α ν β 3-integrin targeted nanoparticles (NP) have been shown to detect and quantify angiogenesis in small-animal tumor models based on 19F-MRI. These promising results using Perfluoro-Crown-Ether labels are currently translated to more clinically-relevant Perfluoro-Octyl-Bromide (PFOB) NP. The complex spectral properties of PFOB and the sensitivity to the target-binding process, as observed in this work, require a thorough optimization of imaging parameters on target. In vitro optimization on fibrin clots and in vivo detection of angiogenesis-targeted NP in the vasculature of Vx2-tumor bearing rabbits by 19F-MRI is demonstrated. 1930. In Vivo CEST-Based Molecular Imaging Using RGD-LipoCEST in U87 Mice Brain Tumor Julien Flament1, Benjamin Marty1, Céline Giraudeau1, Sébastien Mériaux1, Julien Valette1, Christelle Médina2, Caroline Robic2, Marc Port2, Franck Lethimonnier1, Gilles Bloch1, Denis Le Bihan1, Fawzi Boumezbeur1 1NeuroSpin, I²BM, Commissariat ą l'Energie Atomique, Gif-sur-Yvette, France; 2Guerbet, Research Division, Roissy-Charles de Gaulle, France LipoCEST are a new class of contrast agents for CEST-MRI which provide a tremendous amplification factor and can be easily functionalized by grafting specific peptide on their outer membrane in order to target pathology specific biomarker. We present our promising preliminary result to image αvβ3, integrin expressed during tumor growth, with CEST-based MRI using RGD-LipoCEST contrast agents. It constitutes to our knowledge the first attempt towards brain tumor detection using LipoCEST contrast agents in vivo. Martijn Wolters1,2, Marlies Oostendorp1,3, Bram F. Coolen2, Mark J. Post3,4, Gustav J. Strijkers2, Klaas Nicolay2, Walter H. Backes1,3 1Department of Radiology, Maastricht University Medical Center, Maastricht, Netherlands; 2Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 3Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, Maastricht, Netherlands; 4Department of Physiology, Maastricht University, Maastricht, Netherlands The purpose of this study was to evaluate Susceptibility Gradient Mapping (SGM) for molecular MRI to selectively detect tumor angiogenesis in mice with cNGR-labeled SPIOs. SGM is a positive contrast technique to detect susceptibility effects of SPIOs. In this experimental study we found CNR values for SGM comparable to gradient echo (GE) images. Furthermore, a trend towards stronger contrast enhancement for targeted SPIOs compared with untargeted SPIO was perceived. Chase W. Kessinger1, Chalermchai Khemtong1, Osamu Togao1, Masaya Takahashi1, Jinming Gao1 1UT Southwestern Medical Center, Dallas, TX, United States Here we report the use of αvβ3- targeted magnetofluorescent micellar nanoprobes that allowed detection of angiogenic tumor vessels by both fluorescent and magnetic resonance imaging methods. The αvβ3-targeting specificity and temporal tumor accumulation profiles were demonstrated in a human lung tumor xenograft model in nude mice using 3D gradient echo sequences and T2* - weighted dynamic contrast enhancement MRI over one hour. 1933. Lectinized Liposomes for Multimodal in Vivo Molecular Imaging of the Tumor Endothelium Arvind P. Pathak1, Yoshinori Kato1, Nicole Benoit1 1JHU ICMIC Program, Russel H. Morgan Dept. of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States Here we describe the development of dual contrast lectinized liposomes that improve our ability to image the structural and functional changes in tumor blood vessels using MRI and optical imaging. Limitations of conventional contrast-enhanced in vivo MRI include low spatial resolution because of relatively short circulation half-life of such agents, and loss of contrast due to extravasation from permeable tumor vessels. We developed a blood vessel-specific nanoparticle targeted to Bandeiraea Simplicifolia lectin, a carbohydrate-binding protein that binds to α-D-galactosyl residues on endothelial cells. MRI and optical imaging demonstrate that multi-modal, targeted liposomes greatly enhance our ability to characterize tumor angiogenesis. Lei Zhang1, Huiying Zhang1, Kristin Bibee1, Stacy Allen1, Junjie Chen1, Gregory M. Lanza1, Samuel A. Wickline1 1Washington University School of Medicine, St. Louis, MO, United States Disturbed endothelial barrier function in atherosclerosis has been detected by MRI by imaging gadolinium leakage into the vascular interstitium but not yet quantified. Alternatively, we propose that the unique, no background 19F signal from crown ether perfluorocarbon-core nanoparticles (NP: ~250 nm) might both visualize and quantify endothelial disruption in advanced atherosclerosis.For both advanced experimental atherosclerosis and native human atherosclerosis tissues, nontargeted NP rapidly penetrate the leaky endothelial barrier, which can be visualized and quantified ex vivo with the use of ”°no background”± 19F MRI and MRS. This experimental strategy offers a potential new approach for quantification of endothelial dysfunction employing both in vivo and ex vivo incubation with nanoparticle tracers.
1935. MRI-Guided Fluorescence Imaging of Glial Reactivity in Chronic Neuropathic Pain Scott C. Davis1, Lisa H. Treat, 12, Edgar Alfonso Romero-Sandoval2,3, Kimberley S. Samkoe1, Brian W. Pogue1, Joyce A. DeLeo2,3 1Thayer School of Engineering, Dartmouth College, Hanover, NH, United States; 2Department of Anesthesiology, Dartmouth College, Hanover, NH, United States; 3Department of Pharmacology and Toxicology, Dartmouth College, Hanover, NH, United States Glial reactivity plays an important role in the biochemical processes associated with acute and chronic pain and neurodegenerative diseases such as Alzheimers disease, Parkinsons disease, and multiple sclerosis. This study demonstrates the potential to image Glial Fibrillary Acidic Protein (GFAP) expression in the brains of rats after peripheral nerve injury using MR-guided fluorescence molecular tomography (MRg-FMT). MRg-FMT images showed elevated GFAP expression in the brains of injured animals, indicating enhanced astrocytic reactivity as compared to control animals. Quantitative imaging of glial reactivity in vivo would be an important innovation for investigating and deploying new treatment strategies that target glial mechanisms. Manabu Kinoshita1, Yoshichika Yoshioka2, Yoshiko Okita1, Naoya Hashimoto1, Toshiki Yoshimine1 1Department of Neurosurgery, Osaka University Medical School, Suita, Osaka, Japan; 2High Performance Bioimaging Research Facility, Osaka University, Graduate School of Frontier Biosciences, Suita, Osaka, Japan In vivo molecular imaging is a rapidly growing research area both for basic and clinical science. Non-invasive imaging of in vivo conditions in a molecular level will help understand the biological characteristics of normal and diseased tissues without performing surgical invasive procedures. Among various imaging modalities, magnetic resonance imaging (MRI) has gained interest as a molecular imaging modality for its high special resolution. In this research, we have demonstrated that the combined use of HER-2 targeting Affibody, a small 7kDa molecule that behaves similarly to antibodies, and superparamagnetic iron oxide (SPIO) can non-invasively image HER-2 expressing cells or tissues both in vitro and in vivo by MRI. This preliminary study demonstrates that Affibody-SPIO is a feasible target specific contrast agent for in vivo MR-molecular imaging. 1937. Creation of an Multimeric Anti-P53 ScTCR-SPIO Conjugate for the Detection of Cancer in MR Richard Wong1,2, Tian Liu1,2, Xiao-Yun Zhu3, Hing C. Wong3, Yi Wang1,4 1Cornell University, Ithaca, NY, United States; 2Department of Radiology, Cornell University - Weill Medical College, New York, NY, United States; 3Altor Bioscience Corp, Miramar, FL, United States; 4Department of Radiology, Weill Medical College, New York, NY, United States We have created an anti-p53 scTCR-SPIO for use as a generalized cancer detection contrast agent for use in MR. In vitro models demonstrate the effectiveness of this molecule in labeling p53-expressing cells and suggests future application in in vivo cancer models. Imaging of Dementia & Neurodegeneration Hall B Tuesday 13:30-15:30 Takashi Yoshiura1, Akio Hiwatashi1, Koji Yamashita1, Hironori Kamano1, Yukihisa Takayama1, Eiki Nagao1, Tuvshinjargal Dashjamts1, Hiroshi Honda1 1Department of Clinical Radiology, Kyushu University, Fukuoka, Japan We measured mean diffusivities (MD) in subcortical white matter (WM) in 78 different cortical regions using an atlas-based mapping method in 33 patients with Alzheimerfs disease (AD) and 28 healthy control subjects to determine whether the topographical pattern of the diffusion abnormalities can be used to diagnose AD. Uni-variate analysis in which discrimination was attempted based on MD in the single region resulted in the accuracy of 88.5 %. Multi-variate analysis in which a linear discriminant function based on MDs from multiple cortical regions increased the accuracy up to 96.7 %. Takashi Yoshiura1, Akio Hiwatashi1, Koji Yamashita1, Hironori Kamano1, Yukihisa Takayama1, Eiki Nagao1, Tuvshinjargal Dashjamts1, Hiroshi Honda1 1Department of Clinical Radiology, Kyushu University, Fukuoka, Japan We estimated brain regions whose damages are responsible for the deterioration in abstract reasoning ability measured by Ravenfs colored progressive matrices (CPM) in 37 patients with Alzheimerfs disease (AD) (n=19) and mild cognitive impairment (MCI) (n=18) using VBM with non-linear registration based on DARTEL algorithm. A multiple regression analysis was used to map the regions where gray matter volumes were correlated with CPM scores. Significant correlations were seen in 14 regions with the strongest correlation in the left middle frontal gyrus. Results suggested that damages of multiple regions are responsible for deterioration of abstract reasoning ability in AD and MCI. 1940. MRI Shape Analysis Predicts Progression from Mild Cognitive Impairment to Alzheimer's Disease Donald Louis Collins1, Vladimir Fonov1, Simon Duchesne2,3 1McConnell Brain Imaging Center, Montreal Neurological Institute, Montreal, QC, Canada; 2Centre de Recherche Université Laval - Robert Giffard, Quebec, Canada; 3Dépt. de Radiologie, Faculté de Médecine, Université Laval, Quebec, Canada A method is presented to predict conversion from mild cognitive impairment to Alzheimers disease using shape analysis of baseline T1w MRI data. Using 100 MCI subjects from the ADNI database, PCA analysis of deformation fields required to register to a minimum deformation template is used to build a shape model of the aging brain. LDA of the eigenvalues is used to build a classifier to identify converters and non-converters. Testing with 100 additional MCI subjects demonstrates accuracies of 65% at 12 months and 64% at 24 months. Adding baseline HC volume increases accuracy to 73% and 69%, respectively. 1941. Ultra-High Field MRS in Healthy Aging and Early Cognitive Impairment Mary Charlotte Stephenson1, Mirjam I. Schubert2, Maryam Abaei2, Antonio Napolitano2, Rob G. Jones3, Peter G. Morris1, Dorothee P. Auer2 1SPMMRC, School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Academic Radiology, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 3School of Community Healthy Sciences, University of Nottingham, Nottingham, Nottinghamshire Metabolic profiles in the posterior cingulate cortex (PCC) have been found to be altered due to healthy aging and in many neurodegenerative diseases. The purpose of this study was to use increased spectral resolution and signal, available at higher field, to measure changes in the PCC metabolic profile due to healthy aging and cognitive impairment. Atrophy corrected levels of N-acetyl aspartate, glutamate and aspartate were found to significantly decrease with healthy aging. Levels of phosphocreatine were greatly reduced in patients with cognitive impairment, supporting a crucial role for Creatine Kinase dysfunction in dementia. 1942. Cerebral Blood Flow in Alzheimer's Disease by Arterial Spin Labeling QUASAR HKF Mak1, Queenie Chan2, Zhipeng Zhang1, Esben Petersen3, Deqiang Qiu1, Xavier Golay4, Leung-Wing Chu5 1Diagnostic Radiology, University of Hong Kong, Hong Kong, Hong Kong; 2Philips Healthcare; 3Clinical Imaging Research Centre, National University of Singapore, Singapore, Singapore; 4UCL Institute of Neurology, Univeristy College of London, United Kingdom; 5Medicine, University of Hong Kong, Hong Kong Arterial Spin Labeling MRI is a non-invasive method in studying cerebral blood flow, which can be used as an indirect marker of glucose metabolism. In our local Chinese cohort of 13 Alzheimer's disease (mean age- 76.3, MMSE- 16.3) and 15 cognitively normal elderly adults (mean age- 70.8, MMSE- 28.4), QUASAR sequence showed impaired cerebral blood flow in middle & posterior cingulate, bilateral inferior frontal, bilateral superior frontal, right inferior parietal and left superior temporal gyri in AD as compared to controls. This distribution of perfusion impairment is characteristic of moderate Alzheimers disease, analogous to regional hypometabolism in Positron Emission Tomography. 1943. Co-Analysis of Structural Imaging and DTI in Alzheimer's Disease Valerie A. Cardenas1,2, Duygu Tosun1,2, Kristine Yaffe, 2,3, Bruce Miller4, Norbert Schuff1,2, Michael W. Weiner1,2 1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States; 2San Francisco VA, San Francisco, CA, United States; 3Neurology and Psychiatry, UCSF, San Francisco, CA, United States; 4Memory and Aging Clinic, UCSF, San Francisco, CA, United States A voxel-wise co-analysis of structural imaging and DTI is presented and compared to analyses with a single modality only, to determine whether a multi-modality analysis detects effects due to Alzheimer's disease with greater sensitivity. Results show that co-analysis with FA does not detect greater AD-related disease than structural analysis alone. Joseph Mettenburg1, David N. Daniels1, Beau Ances2, Huiling Peng2, Joshua Shimony1, Abraham Z. Snyder1, John C. Morris2, Mark A. Mintun1, Tammie L.S. Benzinger3 1Mallinckrodt Institute of Radiology, Washington University in Saint Louis; 2Neurology, Washington University in Saint Louis; 3Mallinckrodt Institute of Radiology, Washington University in Saint Louis, St. Louis, MO, United States DT-MRI was performed on cognitively normal adults with and without a family history of dementia of the Alzheimers type (DAT). Regional differences were identified in the corpus callosum and parietal white matter in those individuals with confirmed parental history of DAT. These findings support the hypothesis that white matter abnormalities precede the clinically apparent onset of dementia, representing either early pathophysiological changes or fundamental differences in white matter integrity which may place individuals at risk for subsequent development of Alzheimer Disease. Mike P. Wattjes1, Nelleke Tolboom2, Menno Schoonheim1, Jose Maria Garcia-Santos1, Joost P. Kuijer1, Bart N. M. van Berckel3, Philip Scheltens2, Frederik Barkhof1, Ernesto J. Sanz-Arigita1 1Dept. of Radiology, VU University Medical Center, Amsterdam, Netherlands; 2Dept. of Neurology, VU University Medical Center; 3Dept. of Nuclear Medicine, VU University Medical Center These specific perfusion patterns measured by ASL-MRI suggest fundamental differences in the brain perfusion between AD patients and cognitively healthy subjects and could contribution to the diagnoses of AD-related dementia. Ernesto Sanz-Arigita1, Nelleke Tolboom2, Jolanda Boverhoff2, A.A. Lammertsma2, R. Boellaard2, M. Yaqub2, A.D. Windhorst2, Cornelius S. Stam3, Philip Scheltens4, Frederik Barkhof5, Bart van Berckel2 1Radiology, VUmc, Amsterdam, North Holland, Netherlands; 2Nuclear Medicine and PET Research, VUmc, Amsterdam, Netherlands; 3Neurophysiology, VUmc, Amsterdam, Netherlands; 4Neurology, VUmc, Amsterdam, Netherlands; 5Radiology, VUmc, Amsterdam, Netherlands Alzheimer-related differences in basal functional brain networks are likely be related to the regional distribution of neuropathology. To explore this relationship, we have scanned the same population of AD patients and age-matched controls both with fMRI in resting state condition and PET, employing two different amyloid-b tracers: 11C-PIB reveals the distribution of neurofibrillary tangles and 18F-FDDNP binds predominantly to amyloid plaques. The functional networks affected in AD, and the distribution of neuropathology largely overlaps. We will demonstrate the specific relationship between either type of amyloid pathology and particular functional networks. 1947. Pulsed Arterial Spin Labeling Perfusion in Healthy Aging and Early Dementia Christine Preibisch1, Annette Förschler1, Afra Wohlschläger1, Christian Sorg2, Timo Grimmer2, Hans Förstl2, Alexander Kurz2, Claus Zimmer1, Panagiotis Alexopoulos2 1Abteilung für Neuroradiologie, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany; 2Klinik und Poliklinik für Psychiatrie und Psychotherapie, Klinikum rechts der Isar der Technischen Universität München, Munich, Germany Problem: PASL was used to study cerebral perfusion changes in patients with MCI and AD. Methods: Resting CBF maps were obtained from 16 young (30±10a) and 15 elderly (65±5a) cognitively normal controls, 13 patients with MCI (69±9a) and 7 patients with mild dementia in AD (70.9±11.2a). Results: Hypoperfusion was detected in parietal cortex and right angular gyrus when patients were compared to controls. A significant perfusion decrease in parietal cortex and left caudate was also detected in elderly compared to young controls. Conclusion: This suggests that PASL is capable to investigate the transition from normal ageing to dementia.
Zografos Caramanos1,2, Vladimir S. Fonov3, Jacqueline T. Chen, 2,3, Simon J. Francis, 2,3, Alexandre Carmel-Veilleux3,4, Sridar Narayanan, 2,3, D Louis Collins3, Douglas L. Arnold, 2,3 1McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec , Canada; 2NeuroRx Research, Montreal, Quebec, Canada; 3McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada; 4NeuroRx Research, Montreal, Quebec , Canada Precise and accurate quantification of the volume, and longitudinal change in volume, of the lateral ventricles (LV) based on MRI data is an important goal in understanding the natural progression of neurodegenerative disorders such as Alzheimers disease (AD) and multiple sclerosis. In the present study, we provide evidence from 270 AD patients for the accuracy of a novel, fully-automated, MRI-based technique for LV segmentation. Furthermore, we provide preliminary evidence (from a subset of 33 of these patients) for the validity and precision of two novel, fully-automated, MRI-based techniques for the estimation of longitudinal change in LV volume. Rachel DiAnne McKinsey1, Zhifei Wen1, Alan McMillian1, Beth Meyerand1, Sterling Johnson2, Sean Fain1,3, Cindy Carlsson2 1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2GRECC, Veteran Administration Hospital, Madison, WI, United States; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States APOE and vascular dysfunction are associated with increased risk of AD. Changes in perfusion have been identified in APOE carriers verse non-carriers. The application of DSC perfusion with intravenous gadolinium contrast injection to investigate perfusion changes in AD has the ability to provide CBF, CBV, and MTT perfusion maps. We investigated the ability of DSC MRI to measure CBV, CBF, and MTT changes in non-demented children with increased risk for AD due to one or more risk factors: APOE and/or family history.
Guangyu Chen1, Piero Antuono2, Shi-Jiang Li1 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 2Neurology, Medical College of Wisconsin, Milwaukee, WI, United States We tested a hypothesis that the integrity and organization patterns of specific modules (HIP-TP) responsible for memory processing are altered in Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD) subjects, in comparison with cognitively normal (CN) subjects. HIP-TP in CN is very well organized and has highly directed connected bilateral symmetric regions, but the MCI and AD HIP-TP module have fewer directed left and right connections, and the modules are hardly symmetric and organized. There is a potential that patterns of the HIP-TP modules could be employed to distinguish MCI subjects from CN subjects. Guangyu Chen1, B. Douglas Ward1, Shi-Jiang Li1 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States A quantitative Granger causality analysis, which can measure the causal strength among different time series, was employed to identify and quantify the directional hippocampus and default model network in cognitively normal subjects, and detect the changes in the directional network in AD patients. Interestingly in AD subjects, the functional afferents of parahippocampal gyrus is significantly decreased but the efferents of that are increased. And the abnormal network are correlated with abnormal behaviors. 1952. Diffusion Tensor Imaging in Patients with Alzheimers Disease and Mild Cognitive Impairment Sidy Fall1, Souraya El Sankari2, Roger Bouzerar3, Bertille Perin4, Marc-Etienne Meyer5, Olivier Baledent3 1Imaging and Biophysics, University Hospital , Amiens, Picardie, France; 2Institute of Neuroscience, Cliniques Universitaires Saint-Luc, Brussels, Belgium; 3Imaging and Biophysics, University Hospital, Amiens, Picardie, France; 4Neurology , University Hospital, Amiens, Picardie, France; 5Nuclear Medicine, University Hospital, Amiens, Picardie, France We used DTI to investigate inferior fronto-occipital fasciculus (IFO) alterations in patients with Alzheimers disease and Mild Cognitive Impairment (MCI). Within each group, we compared DTI parameters between the two hemispheres in IFO. We found no differences in DTI parameters between the two patients groups. Our results reveal that the longitudinal and radial diffusivities, fractional anisotropy and apparent diffusion coefficient were significantly higher on the right lobe than on the left lobe in AD group. While, Within the MCI group, only FA and radial diffusivity were higher on the right lobe than on the left lobe. Liya Wang1, Felicia C. Goldstein2, Hui Mao1 1Radiology and Emory Center for Systems Imaging, Emory University School of Medicine, Atlanta, GA, United States; 2Neurology, Emory University School of Medicine, Atlanta, GA, United States White matter hyperintensities (WMH) provide an additive effect is considered to be a risk factor of Alzheimer”Æs disease (AD). We investigated which DTI indices: fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (DR) and axial diffusivity (DX) values were more sensitive to differentiate AD from normal control and how different levels of WMH may contribute to AD in specific areas of the white matter. FA and DR were helpful to discriminate AD with different grade of WMH. Different level WMH contributed AD in different regions and extent. The increased DR may provide measurement of demyelination of AD in pathology. Joseph Mettenburg1, David N. Daniels1, Yvette I. Sheline, 12, Beau Ances3, Huiling Peng3, Abraham Z. Snyder1, John C. Morris3, Mark A. Mintun1, Tammie L.S. Benzinger4 1Mallinckrodt Institute of Radiology, Washington University in Saint Louis; 2Psychiatry, Washington University in Saint Louis; 3Neurology, Washington University in Saint Louis; 4Mallinckrodt Institute of Radiology, Washington University in Saint Louis, St. Louis, MO, United States Amyloid plaque deposition in the brain is one of the key pathological hallmarks of Alzheimers disease. Recently, CSF amyloid beta42 peptide levels and PET scans using C-11 Pittsburgh Compound B (PIB) have been established as potential biomarkers for dementia of the Alzheimers type (DAT). Using DTI, we evaluated white matter microstructure in subjects with and without established DAT and identified differences in both the corpus callosum and precuneus. The same white matter findings were identified in non-demented subjects with positive CSF and PIB-PET, suggesting that microstructural abnormalities in white matter integrity may precede cognitive changes in DAT. Hao Huang1, Xin Fan1, Kristin Martin-Cook2, Guanghua Xiao3, Laura Lacritz4, Myron Weiner4, Roger Rosenberg2 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States; 3Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, TX, United States; 4Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States The purpose of this study is to find an effective white matter biomarker of Alzheimers disease (AD) which may indicate disease severity and progression. In this study, DTI and T1 weighted images were acquired from 38 subjects (20 AD, 18 controls). We surveyed all white matter tracts by labeling of the ICBM-DTI-81 digital atlas and correlated FA values of individual white matter tracts with cognitive testing score and cortical atrophy map respectively. The correlation analyses show that tracts in the limbic system, namely fornix and cingulum, are the most sensitive tract to cognitive testing scores and cortical atrophy. Valerie C. Anderson1, David P. Lenar1, Joseph F. Quinn2, William J. Woodward3, Jeffrey A. Kaye2, William D. Rooney3 1Neurological Surgery, Oregon Health & Science University, Portland, OR, United States; 2Neurology, Oregon Health & Science University, Portland, OR, United States; 3Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States Longitudinal water proton (1H2O) relaxation time constants (T1) are strongly associated with macromolecular volume fraction. Here, we report that 1H2O T1 values are increased in the thalamus of subjects with early AD compared to age-matched, cognitively normal controls. Further, we find that the increased 1H2O T1 values in early AD reflect, at least in part, neurodegenerative (macromolecular loss) processes and that contributions to the increased 1H2O T1 values from altered blood water content (via dilation or increased vessel density) are small. Brian Avants1, Phil Cook1, Lyle Ungar1, James Gee1, Murray Grossman1 1University of Pennsylvania, philadelphia, PA, United States We present a novel, unsupervised method, sparse canonical correlation analysis for neuroimaging (SCCAN), that automatically locates correlated sets of voxels in complementary imaging modalities. The method reveals significant and syndrome-specific cortical thickness-diffusion tensor imaging networks in two neurodegenerative diseases, AD and FTD. Subject diagnosis was confirmed by autopsy or CSF-biomarker ratios. The SCCAN summary correlates, in AD, with MMSE reduction and, in FTD, with reduced verbal fluency. Thus, SCCAN identifies disease-specific networks of effects in white matter and cortical thickness that appear in anatomy suspected to be involved in these diseases and that relate specifically to impaired cognitive processes. Barbara Basile1, Mara Cercignani1, Laura Serra2, Roberta Perri3, Camillo Marra4, Lucia Fadda3, Carlo Caltagirone3,5, Marco Bozzali2 1Neuroimaging Laboratory, Santa Lucia Foundation, Rome , Italy, Italy; 2Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy, Italy; 3Clinical and Behavioural Neurology Laboratory, Santa Lucia Foundation, Rome, Italy, Italy; 4Department of Neurosciences, Catholic University of Rome, Roma, Italy, Italy; 5Department of Neurosciences , University of Torvergata, Rome, Italy, Italy Resting-state fMRI was used to investigate changes of functional connectivity (FC) within specific resting-state networks (RSNs) in the presence of Alzheimer's disease (AD) and dementia with Lewy Bodies (DLB) as compared to normal aging. Using ICA analysis, we identified 10 RSNs across subjects. AD patients revealed reduced FC in the posterior cingulate, within the default-mode-network. Conversely, DLB patients showed reduced FC in occipital areas, within the visual network. These findings respectively account for brain disconnection between medial temporal lobes and other association cortexes in the development of AD symptoms, and for occipital abnormalities potentially responsible for visual hallucinations in DLB. 1959. On Using Optimized MRS Acquisitions for Improved Mild Cognitive Impairment Diagnosis Ileana Hancu1, John Cowan2, Earl Zimmerman2 1GE Global Research Center, Niskayuna, NY, United States; 2Albany Medical Center, Albany, NY, United States Accurate and repeatable mI measurements may offer a simple means for diagnosing or monitoring treatment in mild cognitive impairment (MCI) patients. Unfortunately, such repeatable measurements are difficult to obtain in vivo. The current report investigates the capability of CPRESS to better separate MCI subjects from normal controls (NCs). With only 12 subjects in each of the MCI and NC categories, p-values separating the two classes decrease from 0.03 to 0.002 when using CPRESS instead of a short TE PRESS sequence. The impact of more repeatable mI concentration measurements in diagnosing or monitoring MCI evolution or treatment is discussed. 1960. Classification of AD, MCI and Controls Using Large-Scale Network Analysis Gang Chen1, Barney Douglas Ward1, Chunming Xie1, Zhilin Wu1, Wenjun Li1, Jennifer Jones2, Malgorzata Franczak2, Piero Antuono2, Shi-Jiang Li1 1Department of Biophysics,, Medical College of Wisconsin, Milwaukee, WI, United States; 2Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States There has been great interest in developing objective biologically based markers that can be used to predict risk, diagnose, stage, or track the course and treatment of dementia and other neurodegenerative diseases. Alzheimer disease (AD) is the most common form of dementia. Mild cognitive impairment (MCI) is a transitional state between normal aging and dementia, and is often considered a risk factor for AD. In this study, we employed resting-state MRI connectivity methods and the large-scale network analyses to discriminate between AD, MCI and healthy control subjects. 1961. Investigating Parkinsons Disease Using Rotating Frame MRI Silvia Mangia1, Timo Liimatainen2, Igor Nestrasil3, Michael Garwood1, Paul Tuite3, Dennis Sorce1, Shalom Michaeli1 1CMRR - Dept. of Radiology, University of Minnesota, Minneapolis, MN, United States; 2Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for molecular Medicine, University of Kuopio, Kuopio, Finland; 3Dept. of Neurology, University of Minnesota, Minneapolis, MN, United States Rotating frame relaxation (T1rho and T2rho) were measured under a variety of RF pulses (namely continuous-wave, and frequency swept pulses in the adiabatic and subadiabatic regime) on twenty one Parkinson's disease (PD) subjects at 4T. Results demonstrate that different RF pulses significantly modulate the rotating frame relaxations in the substantia nigra (SN), providing the opportunity to extract fundamental parameters of the system based on theoretical modeling of the relaxation channels. The greatest sensitivity to identify sub-regions of the SN was achieved by the so-called RAFF pulse, which combines T1rho and T2rho relaxation mechanisms. Measurements from ferritin samples were additionally performed. 1962. Parkinson”Æs Disease and Imaging of the Substantia Nigra Structure with 7.0T MRI Dae-Hyuk Kwon1, Hye-Jin Jeong1, Se-Hong Oh1, Jong-Min Kim2, Syung-Yeon Park1, Young-Bo Kim1, Beom-Seok Jeon2, Zang-Hee Cho1 1Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea, Republic of; 2Movement Disorder Center, Seoul National University Hospital, Seoul, Korea, Republic of T2* weighted MR image is influenced by iron deposition, so that SN shows up iron-related MRI contrast for all that SN is gray matter. Therefore T2* MR imaging shows great potential in PD study using ultra high field (UHF) 7.0T. And 3D T2* Gradient Echo (GE) sequence makes it possible to study a volumetric analysis and a structural morphometry for SN. This method is validated, despite the reduced SNR associated with fast imaging techniques. And 3D model of the SN shows quite well structural changes in PD case. 1963. Perfusion Networks in Parkinsons Disease Revealed Using Arterial Spin Labeling Tracy R. Melzer1,2, Richard Watts, 1,3, Michael R. MacAskill1,2, Ross Keenan4, Ajit Shankaranarayanan5, David C. Alsop6, Charlotte Graham1,2, Leslie Livingston1, John C. Dalrymple-Alford, 1,7, Tim J. Anderson1,2 1Van der Veer Institute for Parkinson's and Brain Research, Christchurch, New Zealand; 2Medicine, University of Otago, Christchurch, New Zealand; 3Physics and Astronomy, University of Canterbury, Christchurch, New Zealand; 4Christchurch Radiology Group, Christchurch, New Zealand; 5GE Healthcare, Menlo Park, CA, United States; 6Beth Israel Deaconess Medical Center, Boston, MA, United States; 7Pyschology, University of Canterbury, Christchurch, New Zealand Pseudo-continuous ASL was used to investigate cerebral blood flow in 44 Parkinsons disease (PD) patients and 26 controls. Principal component analysis produced a set of covariance patterns which were used to form a perfusion network that successfully distinguished PD from control. The PD-related network was characterized by decreased perfusion in PD versus controls in bilateral posterior parietal-occipital regions, posterior medial cortices, precentral and bilateral middle frontal gyri, and left caudate. Preserved perfusion occurred in bilateral globus pallidus. This ASL-derived PD network provides a marker to objectively gauge disease severity and serves as a potential method to longitudinally track disease progression. 1964. Abnormal Spontaneous Brain Activity in Early Parkinson's Disease Revealed by ALFF Analysis Hong Yang1, Xu-ning Zheng2, Yu-feng Zang3, Yi-lei Zhao1, Jue Wang3, Min-ming Zhang1 1Department of Radiology, First Affiliated Hospital of College of Medical Science, Zhejiang University, Hangzhou, Zhejiang, China; 2Department of Neurology, First Affiliated Hospital of College of Medical Science, Zhejiang University, Hangzhou, Zhejiang, China; 3State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China Using a new biomarker, the amplitude of the low frequency fluct uation (ALFF), the current study is to explore the abnormal spontaneous neural activity of resting state in early PD. Ten early PD patients were compared with eleven gender- and age-matched controls. Data processing was performed using DPARS software. In this study, abnormal ALFF demonstrate that spontaneous neural activity in the resting state is changed in patients with early PD, furthermore, those abnormal neuronal activity should be considered in explaining findings in behavior deficits in early PD. This method is a potential tool to monitor the progression of PD. Christian Denk1, Samantha Palmer2, Martin J. McKeown3, Alexander Rauscher1 1UBC MRI Research Centre, University of British Columbia, Vancouver, BC, Canada; 2Brain Research Centre, Vancouver, BC, Canada; 3Pacific Parkinson's Research Centre, Vancouver, BC, Canada The main pathologic feature of Parkinson's disease (PD) is the loss of dopaminergic neurons in the substantia nigra pars compacta (Snc). There is increasing evidence that iron-mediated oxidative stress via the Fenton reaction is responsible for this loss of neurons. Iron's paramagnetism leads to changes in the relaxation rates R1, R2 and R2* and the phase of susceptibility weighted images (SWI). The aim of this study was therefore to use multi echo SWI for the investigation of both phase and R2* relaxation in deep brain structures of patients with PD. The strongest correlation with phase to the UPDRS score of -0.5 was found in the medial SN pars compacta as well as the largest phase differences between PD patients and controls. A smaller correlation was found with R2*, which is in agreement with previous studies of cerebral R2* in patients with PD. 1966. Susceptibility Mapping of the Substantia Nigra in Parkinson Patients at 7T Andreas Schäfer1, Derek VM. Ott1, Almut Focke2, Johannes Schwarz2, Robert Turner1, Sonja A. Kotz1 1Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2University Hospital Leipzig, Leipzig, Germany Parkinsonās disease is the second most common neurodegenerative disorder in humans. It has been previously demonstrated that transverse relaxation times change in Parkinson patients, supporting pathological findings of increased iron content in the substantia nigra. However, relaxation time is a quite indirect measure of changes in iron concentration, and hard to quantify. Recent studies have used phase images to study neurodegenerative diseases, but this method has the disadvantage that field perturbation maps derived from phase data are non-local. Our study demonstrates that local susceptibility maps, directly indexing iron concentration, can be calculated from phase image data in Parkinson patients. Eva-Maria Ratai1,2, Nazem Atassi, 2,3, Stuart Wallace, 2,4, Jeffery Bombardier1, David Greenblatt5, Merit Cudkowicz, 2,3, Allitia Dibernardo, 2,3 1Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States; 2Harvard Medical School, Boston, MA, United States; 3Neurology, Massachusetts General Hospital, Charlestown, MA, United States; 4Psychiatry, Massachusetts General Hospital, Charlestown, MA, United States; 5Pharmacology & Experimental Therapeutics, Tufts University School of Medicine, Boston, MA, United States The purpose of this study was to evaluate the serum pharmacokinetics of orally administered creatine in subjects with ALS and to assess whether oral intake produces increased concentrations of creatine in the brain utilizing in vivo MR Spectroscopy. Six ALS patients were enrolled in this open-label pilot study. Patients escalated weekly through 3 different dose levels. Creatine serum levels increased with daily use of 5, 10, 15 gm BID. MR Spectroscopy results are suggestive that creatine crosses the blood brain barrier when given at a high dose of 15 gm BID. Furthermore, glutamine and glutamate levels decreased post treatment. 1968. Cross-Sectional and Longitudinal Voxel-Based Relaxometry Study in ALS Don Charles Bigler1, Claire Flaherty-Craig2, Yaman Aksu3, Byeong-Yeul Lee4, Kevin R. Scott2, Helen E. Stephens2, Jeffrey J. Vesek5, Jianli Wang5, Michele L. Shaffer6, Paul J. Eslinger2,5, Zachary Simmons2, Qing X. Yang5,7 1Psychiatry, Penn State Hershey Medical Center, Hershey, PA, United States; 2Neurology, Penn State Hershey Medical Center, Hershey, PA, United States; 3Electrical Engineering, Penn State University, State College, PA, United States; 4Bioengineering, Penn State Hershey Medical Center, Hershey, PA, United States; 5Radiology, Penn State Hershey Medical Center, Hershey, PA, United States; 6Public Health Sciences, Penn State Hershey Medical Center, Hershey, PA, United States; 7Neurosurgery, Penn State Hershey Medical Center, Hershey, PA, United States The objectives of this study were to identify regions of T2 change in ALS cross-sectionally using VBR and determine the relationship of T2 with time, disease duration, and disease severity longitudinally. T1-weighted and multi spin-echo images were acquired from 12 control and 12 ALS at baseline, 7 at 6 months, and 6 at 12 months. After post-processing clusters of significant T2 increase cross-sectionally were found in frontal and temporal areas. Longitudinally, increased T2 was associated with disease duration mainly in frontal areas. Increased T2 in ALS is likely due to atrophy in cortical areas and acute inflammation in subcortical regions. 1969. Regional and Global Cerebral Blood Flow Is Reduced in Patients with Post-Stroke Dementia Jiabao He1, Michael J. Firbank2, Rajesh N. Kalaria2, Baldev Singh2, Paul Danson2, John O'Brien2, Andrew M. Blamire1 1Newcastle MR Centre and Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom; 2Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, United Kingdom Stroke is one of the most important risk factors for dementia. In stroke survivors who do not have immediate, severe cognitive impairment, the risk of developing dementia is significantly increased. Stroke may also exacerbate or trigger the development of neurodegenerative pathology. Small vessel vascular effects may be an important factor in neurodegeneration. We compared CBF in post-stroke patients with and without cognitive decline, patients with Alzheimers disease and healthy controls. Regional and global deficits in CBF were found in patients with post-stroke dementia resembling patterns of change in AD patients, while cognitively intact post-stroke patients had normal CBF. 1970. The Effects of ApoE4 Allele and Age on Subcortical Brain Atrophy in HIV Positive Subjects Linda Chang1, Marilou Andres2, Jeff Sadino1, Caroline Jiang1, Helenna Nakama3, Ute Feger1, Thomas Ernst1 1Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI, United States; 2Pacific Biomedical Research Center, University of Hawaii at Manoa, Honolulu, HI, United States; 3Department of Psychiatry, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI, United States The presence of apolipoprotein (Apo) E4 allele may accelerate the progression of HIV disease, and increase the risk for developing HIV associated neurocognitive disorder (HAND). Whether Apo E4 allele and age may influence subcortical brain atrophy in HIV patients are unknown and were evaluated in this study. Smaller subcortical structures were found in HIV patients with HAND, less so in those with normal cognition. ApoE4 genotype was associated with greater atrophic effects in the younger but not older HIV patients, which suggests that ongoing neuro-inflammatory processes may be more robust and have stronger deleterious effects in the younger patients. 1971. Increased Folding Complexity of the Left Temporal Pole in Temporal Lobe Epilepsy Natalie L. Voets1,2, Boris C. Bernhardt2, Hosung Kim2, Andrea Bernasconi2 1University of Oxford FMRIB Centre, Oxford, Oxfordshire, United Kingdom; 2Montreal Neurological Institute and Hospital, McGill University, NeuroImaging of Epilepsy Laboratory and McConnell Brain Imaging Centre, Montreal, Quebec, Canada Converging histological and radiological data suggest neurodevelopmental abnormalities may play a role in the pathogenesis of drug-resistant temporal lobe epilepsy (TLE). Using surface-based cortical curvature measures, we identified abnormally increased cortical folding in the left temporal pole of patients with both left and right TLE as compared to healthy controls. Increased left temporopolar folding was associated with abnormal positioning of the ipsilateral hippocampus in left TLE patients, and associated with unfavourable surgical outcome in patients with a right-sided seizure focus. These results suggest abnormalities in global limbic network connectivity may play an important role in temporal lobe epileptogenesis. Lydie Nadal-Desbarats1, Helčne Blasco2, Segolene Veau2, Patrick Vourc'h2, Caroline Moreau3, David Devos3, Philippe Corcia4, Christian R. Andres2 1Laboratoire de RMN, INSERM U930 - CNRS 2448 - Université Franēois Rabelais, Tours, France; 2Laboratoire de Biochimie et Biologie moleculaire, Inserm U930-CNRS 2448 - Université Franēois Rabelais, Tours, France; 3Service de Neurologie et Pathologie du Mouvement, EA2683, Hopital R. Salengro - CHRU Lille, Lille, France; 4Centre SLA, CHRU Bretonneau, Tours, France Amyotrophic lateral sclerosis is a progressive neurodegenerative disease. Pathophysiological mechanisms involved in this disease are complex but remain for the most part unknown. This lack of knowledge might explain the absence of reliable biological marker. CSF could be a source of biomarkers. The aim of this study was to analyze CSF of patients with ALS by 1H NMR in order to identify biomarkers in the early stage of the disease, and to evaluate the biochemical factors involved in this disease. We quantified 18 metabolites like amino-acids, organic acids and ketonic bodies. Higher concentrations of metabolites such as ketone bodies contribute to the PCA separation between the two populations. 1973. T1-Weighted Images Detect Motor Neuron Degeneration in ALS Govind Nair1, John D. Carew2,3, Sharon Usher4, Michael Benatar4,5, Xiaoping P. Hu1 1Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, United States; 2Institute for Health Studies, Carolinas HealthCare System, Charlotte, NC, United States; 3School of Public Health, Emory University, Atlanta, GA, United States; 4Department of Neurology, Emory University, Atlanta, GA, United States; 5Department of Epidemiology, Emory University, Atlanta, GA, United States Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease affecting the motor neurons in the brain and spinal cord. VBM analysis performed on T1-weighted images of the brain revealed significant changes in the motor cortex and supporting white matter of ALS patients compared with age-matched healthy control subjects. ROI analysis revealed a significant decrease in signal intensity from these regions, with signal intensity of ALS group showing significant correlation with clinical measures of disease severity. These findings suggest that T1-weighted images may have utility as an imaging biomarker of disease progression in ALS. Ulrich Pilatus1, Joerg Magerkurth1, Nicole Schwan2, Tilmann Wetterling2, Barbara Schneider2 1Institute of Neuroradiology, University Hospital, Goethe-University, Frankfurt, Germany; 2Department of Psychiatry, University Hospital, Goethe-University Cerebral metabolites at day 1 and day 7 of alcohol detoxification therapy were studied using 1H and 31P spectroscopic imaging. Particularly for prefrontal brain, metabolite concentrations correlated with the withdrawal syndrome. The results suggest that less severe symptoms support neuronal recovery while a less pronounced deviation from control values for energy or membrane related compounds is correlated with more severe symptoms. Denis Peruzzo1, Gianluca Rambaldelli2,3, Alessandra Bertoldo1, Marcella Bellani2,3, Roberto Cerini4, Sivlia Marini5, Roberto Pozzi Mucelli5, Michele Tansella2,3, Paolo Brambilla6,7 1Department of Information Engineering, University of Padova, Padova, Italy; 2Inter-University Center for Behavioural Neurosciences, University of Verona, Verona, Italy; 3Department of Medicine and Public Health, University of Verona, Verona, Italy; 4Service of Radiology, Policlinico GB Rossi Hospital, Verona, Italy; 5Department of Morphological and Biomedical Sciences, University of Verona, Verona, Italy; 6Inter-University Center for Behavioural Neurosciences, University of Udine, Udine, Italy; 7Scientific Institute, IRCCS E. Medea, Udine, Italy Abnormalities of Cerebral Blood Flow (CBF) and Volume (CBV) have been observed in schizophrenia patients, suggesting that a disruption of the vascular system may occur in this disease. However, cerebral perfusion is also influenced by several physiologic parameters, not necessarily connected to the pathology. We performed a DSC-MRI analysis to study the role of the demographic information on perfusion parameter estimates between patients with schizophrenia and normal control subjects. We found that differences (i.e. between-subject variability) in CBF and CBV are partially explained by the age and/or by a difference in the subject health conditions. Haiyan Lou1, Desheng Shang2, Minming Zhang1 1Department of Radiology, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China; 2Department of Radiology, The First Affiliated Hospital, Hangzhou, Zhejiang, China none Margaret R. Lentz1, Mona A. Mohamed2,3, Hyun Kim1, Jennifer A. Short1, Mahaveer N. Degaonkar2, Elkan Halpern1, Katherine Conant4, Ned Sacktor5, Ola Selnes5, Peter B. Barker2,3, Martin G. Pomper2 1Department of Neuroradiology/A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, United States; 2Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, United States; 3F. M. Kirby Center for Functional Brain Imaging/Kennedy Krieger Institute, Johns Hopkins Medical Institutions, Baltimore, MD, United States; 4Department of Neuroscience, Georgetown University Medical Center, Washington, DC, United States; 5Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, MD, United States The application of combined antiretroviral (ARV) therapy has been shown to change viral and immune signaling kinetics, indicating that correlations between these and MR measures observed in cross-sectional studies may not last. MRSI, global deficit scorings (GDS) and CSF HIV RNA levels of 51 chronically HIV-infected subjects examined over 10 months of a new ARV administration were included in this study. Mixed model regression analysis indicated that later improvements in subjects GDS were associated with earlier improvements in neuroaxonal function and CSF viral load, suggesting that ARV-mediated decreases in CSF viral levels and neuroaxonal recovery precede improvements in cognitive functioning. 1978. Hippocampus Perfusion Studies of Gulf War Veterans Using OPTIMAL FAIR Xiufeng Li1, Subhendra N. Sarkar2, David E. Purdy3, Qihua Lin4,5, David M. Buhner5, Robert W. Haley5, Richard W. Briggs1,5 1Radiology, UT Southwestern, Dallas, TX, United States; 2Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 3Siemens Healthcare, Malvern, PA, United States; 4Clinical Sciences, UT Southwestern Medical Center, Dallas, TX, United States; 5Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States To verify the previous findings and facilitate futher investigation of the pathological characteristics of Gulf War Illness, a semi-blind hippocampus perfusion study with physostigmine challenge was performed for veterans with Gulf War Syndromes 1, 2 and 3 and healthy veterans in two sessions two days apart: the first session with saline infusion and the second session with physostigmine infusion. New study results are similar to those found in the SPECT studies performed in 1997-1998, indicating that the physiological effects upon hippocampal blood flow still persist a decade later. 1979. White Matter Abnormalities in Tourette Syndrome Extend Beyond Motor Pathways Irene Neuner1,2, Yuliya Kupriyanova3, Tony Stöcker2,4, Oleg Posnansky2, Marc Tittgemeyer3, Frank Schneider1,4, N. J. Shah2,5 1Department of Psychiatry and Psychotherapy, RWTH Aachen University, Aachen, Germany; 2Medical Imaging Physics, Institute of Neuroscience and Medicine - 4, Forschungszentrum Juelich, Juelich, Germany; 3Max-Planck-Institut für Neurologische Forschung, Cologne, Germany; 4JARA Translational Brain Medicine, Germany; 5Department of Neurology,Faculty of Medicine, RWTH Aachen University, Aachen, Germany White matter abnormalities in patients with Tourette syndrome are investigated using diffusion tensor imaging, Tract-Based Spatial Statistics and correlation analysis. Our results indicate that TS is not restricted to motor pathways alone but affects association fibres such as the inferior fronto-occipital fascicle, the superior longitudinal fascicle and fascicle uncinatus as well. The detected abnormalities in Tourette patients complement the idea of the developmental character of the disorder. They show a pathological pattern reaching beyond the corticospinal tract. The alteration pattern of decreased fractional anisotropy and increased radial diffusivity might indicate a deficit myelination as one pathophysiologic factor in Tourette.
1980. Persistent Basal Ganglia NAA/Cr Ratio Differences in Gulf War Illness Sergey Cheshkov1,2, Audrey Chang1, Hyeon-Man Baek1, Sandeep Ganji1, Evelyn Babcock1, Richard Briggs1,2, Robert Haley2 1Radiology, UT Southwestern Medical Center, Dallas, TX, United States; 2Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States Decrease in the N-acetylaspartate to creatine ratio (NAA/Cr) was previously measured via magnetic resonance spectroscopy at 1.5T in bilateral basal ganglia, pons, and in left hippocampus of Gulf War Illness patients. The Seabees cohort veterans (controls, Syndrome 1, 2, and 3 patients) studied in 1997-1998 recently participated in a follow-up study at 3T. The group comparison of this new spectroscopic data indicates reduced NAA/Cr ratio in all three Syndrome groups compared to the control group, the decrease is significant in the left and nearly significant in the right basal ganglia. This finding indicates possible neuronal damage in the affected population. Aman Ish Goyal1, Parina Gandhi1, Yan Fang1, Lei Jiang1, Luo Ouyang1, Sandeep Ganji1, David Buhner2, Wendy Ringe3, Kaundinya Gopinath1,2, Richard Briggs1,2, Robert Haley2 1Department of Radiology, UT Southwestern Medical Center, Dallas, TX, United States; 2Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States; 3Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, United States Previous studies have shown higher cooling and warming thresholds in hands and feet of Gulf War (GWI) veterans. In this study, brain activation to warm sensation stimuli and hot pain stimuli was measured with a quantitative sensory testing (QST) fMRI paradigm, in GWI veterans with Syndromes1 (Syn1), Syn2 and Syn3, as well as age-matched controls. Syn2 and Syn1 groups exhibited significantly decreased brain activation during warm sensation compared to controls. On the other hand, Syn2 and Syn1 groups evoked significantly higher activation to hot pain stimuli in a number of pain processing areas. 1982. Advanced Mr Imaging of Active Duty Military Personnel Following Acute Blast-Related Tbi Christine Louise MacDonald1, Dana Cooper1, John Witherow2, Abraham Snyder3, Joshua Shimony3, Marcus Raichle3, Stephen Flaherty2, Raymond Fang2, David Brody1 1Neurology, Washington University, Saint Louis, MO, United States; 2Landstuhl Regional Medical Center, Landstuhl, Germany; 3Radiological Sciences, Washington University, Saint Louis, MO, United States Military personnel have a higher rate than civilians of Traumatic Brain Injury (TBI) even during times of peace. TBI has been called the signature injury of the wars in Iraq and Afghanistan . Many of these injuries occur as the result of blast exposure, but little is known about the characteristics of blast-related TBI. Diffusion tensor imaging (DTI) was employed for this study of 85 active duty military personnel (20 control, 65 TBI). Abnormalities were found on DTI that were not apparent on conventional imaging. This is the first time this has been observed in this particular population. 1983. Transverse Relaxation Measurements of Brain Metabolites in Gulf War Illness Audrey Jennifer Chang1, Sergey Cheshkov1,2, Richard Briggs1,2, Robert Haley2 1Radiology, UT Southwestern Medical Center, Dallas, TX, United States; 2Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States Relaxation times are often an assumed value in spectroscopy studies, despite their potential diagnostic value and usefulness in quantifying metabolite concentrations. The purpose of this study was to measure the transverse (T2) relaxation times of the major brain metabolites (NAA, Crt, and Chot) in left and right basal ganglia of veterans with Gulf War Illness (GWI) and age-matched veteran controls to determine if the T2 values differ between ill veterans and controls or among the three syndrome variants of GWI. 1984. Reduced Hippocampal Body Functional Connectivity in Gulf War Illness Yan Fang1, Luo Ouyang1, Cybeles Onuegbulem2, Aman Goyal1, Lei Jiang1, Parina Gandhi1, Sandeep Ganji1, Wendy Ringe2, Kaundinya Gopinath1,3, Richard Briggs1,3, Robert Haley3 1Department of Radiology, UT Southwestern Medical Center, Dallas, TX, United States; 2Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, United States; 3Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX, United States Memory loss is a common complaint among veterans with Gulf War Illness (GWI), and preliminary studies have documented hippocampal dysfunction in GWI. Abnormal functional connectivity to hippocampus has also been observed in various other diseased populations. This study used resting state or functional connectivity MRI (fcMRI) to examine functional connectivity of the hippocampus in GWI subjects. GWI veterans exhibited significantly reduced connectivity to left and right hippocampal body in a number of brain regions, indicating disruption of hippocampal networks and/or damage to hippocampus in GWI. Keith S. Cover1, Frederik Barkhof1, Alex Zijdenbos2, Christian Spenger2, Richard McClatchey3, David Manset4, Lars-Olof Wahlund5, Yannick Legre6, Tony Solomonides6, Giovanni B. Frisoni7 1VU University Medical Center, Amsterdam, Netherlands; 2Prodema Medical; 3University of the West of England; 4MAAT G Knowledge SL; 5Karolinska Institutet; 6HealthGrid; 7Fatebenefratelli neuGRID is developing a new user-friendly Grid-based research e-Infrastructure enabling the European neuroscience community to carry out computer intensive research required for the pressing study of degenerative brain diseases (for example, the Alzheimer disease). In neuGRID, the archiving of large amounts of imaging data is paired with hundreds of CPUs and a variety of software packages. Neuroscientists will be able to identify neurodegenerative disease markers through the analysis of 3D magnetic resonance brain images via the provision of sets of distributed medical and GRID services. The infrastructure is designed to be expandable to services for other medical applications and is compliant with EU and international standards regarding data collection, data management, and Grid construction. Aigerim Djamanakova1, Andreia V. Faria2, Kenichi Oishi2, Xin Li2, Kazi Akhter2, Laurent Younes3,4, Peter van Zijl2,5, Michael Ira Miller3, Susumu Mori2 1Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD, United States; 2Radiology, Johns Hopkins University, Baltimore, MD, United States; 3Center for Imaging Science, The Johns Hopkins University, Baltimore, MD, United States; 4Applied Mathematics & Statistics, Johns Hopkins University, Baltimore, MD, United States; 5F.M. Kirby Center for Functional Magnetic Resonance Imaging, Kennedy Krieger Institute, Baltimore, MD, United States We used Large Deformation Diffeomorphic Metric Mapping in order to improve the registration of brains with enlarged ventricles from patients with Alzheimer's disease . By employing a second channel of information comprised of the lateral ventricle segmentation maps, obtained semi-automatically and automatically, we were able to increase the accuracy of the mappings. The degree of accuracy was calculated by comparing the results of the manual segmentation of lateral ventricles and a neighboring structure, lingual gyrus, with the single and dual-channel registration-based segmentation. This approach can be a powerful tool for improving registration of images. Love Erlandsson Nordin1,2, Leif Svensson1,2, Per Julin3,4, Susanne Müller5, Terri Louise Lindholm1,2 1Medical Physics, Karolinska University Hospital Huddinge, Stockholm, Sweden; 2SMILE Image Laboratory, Karolinska University Hospital Huddinge, Stockholm, Sweden; 3AstraZeneca R&D Neuroscience, Södertälje, Sweden; 4Clinical Geriatrics, Karolinska University Hospital Huddinge, Stockholm, Sweden; 5Radiology, Karolinska University Hospital Huddinge, Stockholm, Sweden The aim of this study has been to optimize the contrast parameters of the MPRAGE sequence for fully automatic brain tissue segmentation. The goal has been to achieve as reliable and reproducible volumetric measurements of the human brain as possible. The optimization was carried out on a 3 T MRI unit using 2 different multi array head coils (12 and 32 channels) and 9 healthy young volunteers. The study also includes a comparison of the reproducibility in measurement between the two head coils. The results show that it is possible to achieve good reproducibility in measurement for the total brain volume and the 12 channel head coil gives slightly more reproducible results. Robert John Dawe1, David A. Bennett2, Julie A. Schneider2, Konstantinos Arfanakis1 1Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, United States; 2Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, United States Postmortem MRI of the human brain offers several advantages over in vivo imaging. For example, histological analysis can be performed following the MR scan, allowing for verification of imaging findings and testing of new MRI diagnostic techniques. Spatial transformation of individual postmortem brain MRI volumes to a common reference would facilitate voxel-based investigations, which would provide information throughout the brain in a timely manner and without user bias, in contrast to ROI-based analyses. In this work, population-based methods were used to create an MRI template that is suitable for high dimensional spatial normalization of postmortem human cerebral hemispheres. Chan Hong Moon1, Jung-Hwan Kim1, JinHong Wang1, Kyongtae Ty Bae1 1University of Pittsburgh, Pittsburgh, PA, United States We demonstrated excellent tissue contrast of the lateral geniculate nucleus (LGN) with suppression of signals from the surrounding white matters, such as optic radiation using an (inversion-recovery) MPRAGE sequence with appropriate TI at 3T and 7T. The LGN was superiorly delineated with a high SNR at 7T, as compared to 3T. An imaging method that allows for accurate and reliable volume measurement of LGN is essential for the investigation of the association between LGN atrophy in vivo and neurodegenerative glaucoma. J. B.M. Warntjes1,2, J. West1,3, R. Birgander4, P. Lundberg5 1Center for Medical Imaging Science and Visualization (CMIV), Linköping, Sweden; 2Department of Medicine and Health, Division of Clinical Physiology, Linköping, Sweden; 3, Department of Medicine and Health, Division of Radiation Physics, Linköping, Sweden; 4Department of Radiology (NUS), Department of Radiation Sciences, Umeå, Sweden; 5Department of Medicine and Health, Division of radiation physics, Linköping, Sweden A method is described to measure the partial volume fraction of cerebrospinal fluid for each voxel in a complete brain volume within a scan time of 5 to 6 minutes, based on quantification of the relaxation rates R1 and R2 and proton density. This measurement allows to accurately segment the brains ventricular system independent of image resolution and without user-dependent image thresholding. Jacobus FA Jansen1, Marielle Vlooswijk2, H Majoie2, Paul Hofman2, Marc De Krom2, Albert Aldenkamp2, Walter H. Backes2 1Medical Physics, MSKCC, NY, United States; 2MUMC, Maastricht, Netherlands Although cognitive dysfunction is a prevalent co-morbidity in patients with chronic epilepsy, it is not clear whether these patients display cerebral abnormalities that are related to the cognitive impairment that can be detected with in vivo magnetic resonance (MR) techniques. This report study aims to determine neuronal determinants of cognitive impairment in patients with chronic epilepsy. Quantitative MR, comprising T2 relaxometry, diffusion tensor imaging, and spectroscopic imaging, was applied to detect possible neuronal correlates in terms of micro-structural and metabolic abnormalities.
Cathy Scanlon1, Susanne G. Mueller2, Duygu Tosun2, Ian Cheong2, Michael W. Weiner2, Ken D. Laxer3 1Center for Imaging of Neurodegenerative Diseases , Dept. of Radiology and Biomedical Imaging, University of California,, San Francisco, CA, United States; 2Center for Imaging of Neurodegenerative Diseases, Dept. of Radiology and Biomedical Imaging, University of California,, San Francisco, CA, United States; 3Pacific Epilepsy Program, California Pacific Medical Center, San Francisco, CA, United States Deformation-based morphometry (DBM) was applied to 2 sub-groups of temporal lobe epilepsy (TLE); 15 patients with mesial temporal sclerosis (TLE-mts) and 14 with normal MRI on visual inspection (TLE-no). TLE-mts demonstrated extensive extra-hippocampal abnormalities when compared with controls (n=33). TLE-no demonstrated more subtle but significant findings not previously reported with a similar analysis in voxel based morphometry (VBM). This may suggest DBM to be a more sensitive approach to detect subtle volume changes in this group. Jieun Kim1, In-Young Choi1,2, Mary L. Michaelis3, Sang-Pil Lee1,4 1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States; 2Neurology, University of Kansas Medical Center, Kansas City, KS, United States; 3Pharmacology & Toxicology, University of Kansas, Lawrence, KS, United States; 4Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, United States Axonal transport impairment has been implicated as a common mechanism of Alzheimerās disease progression. A newly developed microtubule stabilizing agent, TH237-A, is known for protecting neurons against Aβ toxicity, decreasing abnormal tau phosphorylation in cultured neurons, and permeating the blood-brain barrier. We have investigated the efficacy of TH237-A in preserving axonal transport integrity in an animal model of AD, 3xTg-AD mice, over one year by measuring axonal transport rates in olfactory bulbs using manganese enhanced MRI. Results show that the drug does not reverse axonal transport deficits but may be effective in preventing further axonal transport impairment. Santosh Kumar Yadav1, Amit Goel2, Vivek A. Saraswat3, Arti Srivastava1, Sanjay Verma4, Ram Kishore S. Rathore5, Michael A. Thomas6, Chandra M. Pandey7, Kashi N. Prasad4, Rakesh K. Gupta1 1Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 2Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences Lucknow India, Lucknow, UP, India; 3Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 4Mathematics and Statistics, Indian Institute of technology, Kanpur, UP, India; 5Mathematics and Statistics, Indian Institute of technology Kanpur, Kanpur, Uttar Pradesh, India; 6Radiological Sciences, UCLA School of Medicine, Los Angeles, CA, Los Angeles, CA, United States; 7Biostatistics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, UP, India Thirty-one EHPVO patients along with 23 controls were included in this study. All subjects underwent for neuropsychological tests, measurement of blood ammonia, MR imaging, 1H-MR spectroscopy. Serum cytokines were measured only in 10 patients and 8 controls. MHE was present in 45% patients. Significantly increased ammonia, Glx/Cr, and cytokines and MD with decrease in mI/Cr and MTR with no change in Cho/Cr were noted in patients with MHE compared to controls. Significantly increased Glx/Cr and blood ammonia indicates its central role in the pathogenesis of EHPVO related MHE. The presence of significant increased serum cytokines in these patients suggest that inflammation also pay an important role in the pathogenesis of MHE. Santosh Kumar Yadav1, Amit Goel2, Vivek A. Saraswat2, R KS Rathore3, M A. Thomas4, A Yadav1, K N. Prasad5, C M. Pandey6, Rakesh Kumar Gupta1 1Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 2Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 3Mathematics and Statistics, Indian Institute of technology Kanpur, Kanpur, Uttar Pradesh, India; 4Radiological Sciences, UCLA School of Medicine, Los Angeles, CA, Los Angeles, CA, United States; 5Microbiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 6Biostatistics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India Thirty-three cirrhotic MHE and 14 EHPVO MHE with 23 age/sex matched control were included in final analysis. Liver function test, NPT, CFF, blood ammonia, proinflammatory molecules, MR imaging and 1H MR spectroscopy were recorded in all patients. MHE was significantly higher in cirrhosis than EHPVO. Significantly increased blood ammonia, proinflammatory molecules, Glx/Cr and MD with decreased mIns/Cr was observed in both form of MHE as compared to controls, however Cho/Cr significantly decreased only in cirrhotic MHE as compared to EHPVO MHE and controls. Increased blood ammonia, proinflammatory molecules, Glx/Cr and MD with decreased mIns/Cr is common in both form of MHE and involved the pathogenesis of MHE, however Cho/Cr depletion was observed only in cirrhotic MHE, confirms that Cho/Cr depletion is related to liver dysfunction and is unrelated to MHE. Our study confirms that there are differences in biochemical, proinflammatory molecules and MR profile in MHE of cirrhosis and EHPVO. Chunming Xie1,2, Wenjun Li1, Joseph Goveas1, Piero Antuono1, Jennifer Jones1, Guangyu Chen1, Malgorzata Franczak1, Zhilin Wu1, Shi-Jiang Li1 1Medical College of Wisconsin, Milwaukee, WI, United States; 2Neurology, School of Clinical Medicine, Southeast University, Nanjing, Jiangsu, China The purpose of this study was to identify neural correlates of depressive symptoms and memory deficits in the amygdala functional connectivity network (AFCN) in elderly with or without amnesic mild cognitive impairment (aMCI) using the resting state functional connectivity MRI technique. aMCI subjects showed abnormal AFCN activity and the significant different correlation patterns in the distinct nodes within the AFCN correlated to depressive symptoms and memory deficits. This suggests the AFCN has dual effects that link depressive symptoms and memory deficits. The altered neural substrates of the AFCN underlying the emotional and cognitive functions mediation were associated with disease state. 1997. Assessing the Effect of Age on Voxel-Based Relaxometry of Epileptic Patients Rachel Sharkey1,2, Robert Karl Kosior, 1,3, Paolo Federico1,2, Richard Frayne, 12 1Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, AB, Canada; 2Radiology and Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; 3Biomedical Engineering, University of Calgary, Calgary, AB, Canada Our objective was to assess the effect of age on T2 for voxel-based relaxometry (VBR) analysis. Regressions of T2 versus age were run on data from healthy controls with a voxel-based analysis and with regions of interest. For controls and epileptic patients, VBR was performed once with age included as a nuisance variable, and once without. The correlation was variable across the brain, and significant (p < 0.05) in four regions, including the hippocampus (decreasing T2 with age). Without adjusting for age, discrepancies in VBR findings are found in younger and older patients. Normal Aging Brain Hall B Wednesday 13:30-15:30 1998. A Multiparametric Study of White Matter Integrity and Cognition in Old Age Susana Muńoz Maniega1, Lars Penke2, Marķa C. Valdés Hernįndez1, Catherine Murray2, Natalie A. Royle1, Alan J. Gow2, Jonathan D. Clayden3, John M. Starr4, Mark E. Bastin5, Ian J. Deary2, Joanna M. Wardlaw1 1Clinical Neurosciences, University of Edinburgh, Edinburgh, United Kingdom; 2Psychology, University of Edinburgh, Edinburgh, United Kingdom; 3Institute of Child Health, University College London, London, United Kingdom; 4Geriatric Medicine, University of Edinburgh, Edinburgh, United Kingdom; 5Medical Physics, University of Edinburgh, Edinburgh, United Kingdom Using diffusion MRI tractography we segmented white matter tracts thought to be related with cognition in a cohort of healthy older people. We registered the tract segmentations to parametric maps of magnetization ratios and T1 relaxation times and used these parameters, as well as fractional anisotropy and mean diffusivity, to characterise the white matter integrity of the tracts. The study of how tract integrity relates to cognition in old age revealed new relationships not shown by diffusion parameters only. This work suggests that a multi-parameter approach could unravel the effects of ageing on the brain and cognition better than the lone use of diffusion MRI. 1999. Rates of Brain Tissue Changes in the General Population of Elderly - The AGES-Reykjavik Study Sigurdur Sigurdsson1, Thor Aspelund1,2, Lars Forsberg3, Jesper Fredriksson3, Olafur Kjartansson, 1,4, Palmi V. Jonsson, 1,4, Gudny Eiriksdottir1, Tamara B. Harris5, Alex Zijdenbos6, Mark A. van Buchem7, Lenore J. Launer5, Vilmundur Gudnason1,2 1The Icelandic Heart Association, Kopavogur, Iceland; 2The University of Iceland, Reykjavik, Iceland; 3Raforninn Inc, Reykjavik, Iceland; 4The University Hospital of Iceland, Reykjavik, Iceland; 5The National Institute on Aging, Bethesda, United States; 6Biospective Inc, Montreal, Canada; 7Leiden University Medical Center, Leiden, Netherlands Estimations on age-related rate of changes of brain tissues have mostly been gathered from cross-sectional MRI studies. A limitation of cross-sectional design is the inability to directly assess intra-individual change. Longitudinal studies on brain tissues and age in large population cohorts are lacking. We compared estimated rates of cross-sectional and longitudinal changes with age in brain tissues in a population-based cohort of 4614 older persons. The longitudinal data show a substantially higher age-related rate of change in tissue volumes when compared to the cross-sectional estimates and show that the cross-sectional data underestimates the rate of change in brain tissues. 2000. Effects of Sex and Age on Regional Frontal Lobe Gray Matter Distribution Vanessa Anne Sluming1,2, Andrew Mayes3, Iain D. Wilkinson4, Charles Romanowski4, Enis Cezayirli5, Patricia E. Cowell6 1School of Health Sciences, University of Liverpool, Liverpool, Merseyside, United Kingdom; 2Magnetic Resonance and Image Analysis Research Centre, University of Liverpool, Liverpool, Merseyside, United Kingdom; 3School of Psychology, University of Manchester, Manchester, United Kingdom; 4Academic Department of Radiology, University of Sheffield, United Kingdom; 5Department of Anatomy, University of Celal Bayar , Turkey; 6Department of Human Communication Sciences, University of Sheffield, United Kingdom VBM analysis of grey matter distribution within the healthy adult brain was undertaken, in a sample of 31 males and 35 females (age range: 20-72 years) to investigate sex differences in the effect of brain ageing. Data were analysed using a full factorial analysis (2x2x2). There were no significant sex by age effects. Within sex regression analyses revealed that females showed age related GM decrements within several frontal regions tending medially, whereas males sowed age related decrements in bilateral structures including IFG (BA44/45). These findings are discussed. 2001. White Matter Lesion Intensity and Cognitive Ability: Relationships in Youth and Old Age Maria Valdés Hernandez1, Lars Penke2, Susana Muńoz Maniega1, Catherine Murray2, Natalie Royle1, Alan J. Gow2, John M. Starr3, Mark E. Bastin4, Ian J. Deary2, Joanna M. Wardlaw1 1Clinical Neurosciences, University of Edinburgh, Edinburgh, United Kingdom; 2Psychology, University of Edinburgh, Edinburgh, United Kingdom; 3Geriatric Medicine, University of Edinburgh, Edinburgh, United Kingdom; 4Medical Physics, University of Edinburgh, Edinburgh, United Kingdom Intensity of white matter lesions (WMLs) on structural MRI may be linked to the severity of underlying white matter damage, and hence to old age cognitive decline. Here we investigate relationships between the volumes of intense (i) and less-intense (Li) WMLs in a unique cohort of ? subjects in whom cognitive ability is available in both youth (11 years) and old age (72-73 years). iWMLs were predominant located in frontal areas, while LiWMLs were mainly located posteriorly. iWMLs had a stronger relationship with cognition than LiWMLs in both youth and old age. These findings support the frontal ageing hypothesis. 2002. Investigation of Cerebral Ischemic Disease in the Aged with Aortic Stenosis Ping Wang1, Elizabeth Strambrook2, Michel Bilello1, Thomas Floyd3 1Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Anesthesiology & Critical Care, University of Pennsylvania, Philadelphia, PA, United States; 3Anesthesiology & Critical Care, and Neurology, University of Pennsylvania, Philadelphia, PA, United States To test the correlations of aging, sex, and aortic stenosis (AS) degree with the severity of pre-existing white matter and ischemia-like lesions. Aging was associated with rapidly progressive cerebral ischemic disease; female sex accounted for a 56% increased in lesion volume over men; while the severity of AS did not demonstrate statistical significance in influencing lesion volume, univariate analysis demonstrated an important trend of increasing lesion volume with increasing severity of AS. Ai Wern Chung1, Rebecca A. Charlton1, Nigel C. Lawes2, Robin G. Morris3, Hugh S. Markus1, Thomas R. Barrick1 1Centre for Clinical Neuroscience, Saint George's University of London, London, United Kingdom; 2Graduate Medical School, University of Limerick, Limerick, Ireland; 3Department of Psychology, Institute of Psychiatry, King's College University of London, London, United Kingdom We present a novel technique applying probabilistic diffusion tensor tractography on longitudinal data to assess white matter structural integrity in ageing subjects over a period of two years. Our method was able to consistently extract white matter tracts associated with working memory over time and between two ageing cohorts (middle-aged and elderly). Tract connections were found between the fronto-temporal, fronto-parietal and temporo-parietal lobes. Our study suggests a decrease in white matter structural integrity of these tracts with age could be related to the decline in working memory performance. Mark E. Bastin1, Maria Valdés Hernandez2, Susana Muńoz Maniega2, Catherine Murray3, Alan J. Gow3, Paul A. Armitage2, Joanna M. Wardlaw2, Ian J. Deary3 1Medical Physics, University of Edinburgh, Edinburgh, United Kingdom; 2Clinical Neurosciences, University of Edinburgh, Edinburgh, United Kingdom; 3Psychology, University of Edinburgh, Edinburgh, United Kingdom White matter lesions are a common finding on T2- and FLAIR-weighted MRI scans of older subjects, but their etiology and relationship to cognitive function remains unclear. The aim of this pilot study was to characterize differences in magnetization transfer ratio and spin-lattice relaxation time between macroscopically normal-appearing white matter and white matter lesions in a subset of a unique cohort of aging subjects, the Lothian Birth Cohort 1936. 2005. Hypertension, Arterial Health and Neuronal Integrity in Midlife Andreana P. Haley1,2, Tarumi Takashi3, Jun Sugawara3, Hirofumi Tanaka3 1Psychology, The University of Texas at Austin, Austin, TX, United States; 2UT Imaging Research Center, Austin, TX, United States; 3Kinesiology, The University of Texas at Austin, Austin, TX, United States The present study bridges the gap between midlife hypertension and late-life cognitive impairment, a relationship that has long been documented but remains poorly understood. We demonstrate that midlife hypertension and associated arterial thickening relate to cerebral measures of neuronal health and viability in middle-aged adults with intact cognitive performance.
Tae-Hoon Kim1, Gwang-Woo Jeong1,2, Han-Su Baek1, Gwang-Won Kim1, Heoung-Keun Kang2, Jong-Chul Yang3, Kwangsung Park4 1Interdisplinary Program of Biomedical Engineering, Chonnam National University Medical School, Gwangju, Korea, Republic of; 2Radiology, Chonnam National University Medical School, Gwangju, Korea, Republic of; 3Psychiatry, Chonbuk National University Hospital, Chonbuk, Korea, Republic of; 4Urology, Chonnam National University Medical School, Gwangju, Korea, Republic of With menopause, women underwent changes of overall hormones, leading to functional changes of organs. A majority of menopausal women experience some exchanges in sexual function. Using fMRI technique, menopausal a few papers concerning differential brain activation patterns between premenopausal and menopausal women were published. However, it is unclear how brain metabolite change in menopause affects sexual arousal. The purpose of this study was to investigate the brain metabolic changes associated with visual sexual arousal in premenopausal and menopausal women using functional MR spectroscopy (fMRS). Sarah Andrea Wijtenburg1, Kathleen L. Fuchs2, Virginia I. Simnad3, Jack Knight-Scott1 1Radiology, Children's Healthcare of Atlanta, Atlanta, GA, United States; 2Neurology, University of Virginia, Charlottesville, VA, United States; 3Neurology, Evergreen Hospital Medical Center, Kirkland, WA, United States Here, we build upon our earlier work incorporating a CHESS pulse into a STEAM sequence by presenting a new method for analyzing and interpreting motion data collected from three age groups: healthy young (HY), healthy middle-aged (HM), and healthy elderly (HE). Our results show that listed in increasing order of motion during a 1H MRS STEAM spectroscopy examination: HY, HM, and HE. 2008. Cross-Site Reproducibility of 1H-MRS Irene Margaret Vavasour1, Cornelia Laule1, Burkhard Maedler2, Trudy Harris1, David K.B. Li1, Anthony L. Traboulsee3, Alex L. MacKay1 1Radiology, University of British Columbia, Vancouver, BC, Canada; 2Physics and Astronomy, University of British Columbia; 3Medicine, Univeristy of British Columbia Quantitative assessment of 1H-MRS metabolite concentrations has the potential to be an in-vivo marker for disease progression and treatment efficacy in pharmaceutical trials. The present study examines cross-site reproducibility of 1H-MRS metabolite concentrations measured on the same 5 people at 6 sites. Average percent differences of inter and intra-site reproducibility was <10% for n-acetyl-aspartate and myo-Inositol, <7% for creatine, <8% for choline and <21% for glutamate and glutamine. All percent differences between sites were of a similar magnitude increasing confidence in comparing results from across the sites. 2009. Aging Effects on the Functional Connectivity in the Resting Brain Zhengjun Li1,2, Aniseh Kadivar3, John Pluta3, Holly D. Soares4, Murray Grossman3, John Detre3, Ze Wang5 1Dept. of Biomedical Engineering, Shanghai Jiao Tong University, China; 2Dept of Psychiatry, University of Pennsylvania, United States; 3Dept of Neurology, University of Pennsylvania, United States; 4Pfizer Inc, United States; 5Dept of Psychiatry, University of Pennsylvania, Philadelphia, PA, United States Functional connectivity (FC) and the default mode network represents two recent active research directions in fMRI. Previous studies have shown the aging effect in resting FC based on independent component analysis or concurrent task involved fMRI defined region-of-interests (ROIs). No published work has assessed the aging effects on resting FC in the DMN using the seed region based method. To meet this gap, we here report some preliminary results of the aging inter-region FC in the normal brain using resting fMRI and found age-dependent FC decrease in anterior cingulate cortex and posterior cingulate cortex. 2010. Correlation Between Venous Blood T1 and BOLD FMRI in Young and Elderly Subjects Lirong Yan1, Yan Zhuo1, Bo Wang1, Cheng Li2, Jiongjiong Wang2 1Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; 2Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States We investigated the relationship between in vivo measurement of venous blood T1 and BOLD signal changes during visual stimulation in two groups of young and elderly subjects. There was a significant negative correlation between venous blood T1 and BOLD activation across subjects. Upon including venous blood T1 as a covariate, the differences in BOLD activation between the two age groups weakened, suggesting that aging effects on BOLD fMRI may be partly attributed to baseline hematocrit variations. 2011. Increased Resting State Connectivity Between Left and Right Hemispheres with Increasing Age Daniel Joshua Cox1,2, Rafat S. Mohtasib3, Daniela Montaldi4, Laura M. Parkes1,2 1Imaging Sciences and Biomedical Engineering, School of Cancer and Imaging Sciences, The University of Manchester, Manchester, Lancashire, United Kingdom; 2Biomedical Imaging Institute (BII), The University of Manchester, Manchester, Lancashire, United Kingdom; 3Magnetic Resonance and Image Analysis Research Centre (MARIARC), University of Liverpool, United Kingdom; 4School of Psychological Sciences, The University of Manchester, Manchester, Lancashire, United Kingdom This study aims to investigate changes in resting state functional connectivity with increasing age. 40 healthy subjects (aged 20 76) participated. Gradient echo EPI images were collected during a Stroop task and active regions were found across the group. The BOLD amplitude in the right middle frontal gyrus (MFG) increased with age, reducing laterality of activation. Partial correlation was used to investigate functional connectivity between bilateral MFG, which was found to increase with age between bilateral MFG in adults aged 40yrs+. Increased connectivity was also associated with improved accuracy, suggesting alterations in functional connectivity may be important for performance. Vesa Kiviniemi1, Harri Littow1, Ahmed Abou-elseoud1, Katariina Mankinen2, Jukka Rahko3, Jukka Remes1, Juha Nikkinen1, Tuomo Starck1, Juha Veijola4, Christian Beckmann5, Osmo Tervonen1 1Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; 2Pediatric department, Oulu University Hospital, Oulu, Finland; 3Child Psychiatry, Oulu University Hospital, Oulu, Finland; 4Psychiatry, Oulu University, Oulu, Finland; 5Clinical Neuroscience, Imperial College, London, United Kingdom Resting state networks undergo various age related changes both in strength and spatial distribution. Some occur in adolescence while many changes also occur later in adulthood. A salience network splits without much strength in any age group. These different findings reflect multiple normal ageing processes of the central nervous system. 2013. Age-Related Differences of Brain Activation Patterns Upon Imaginary Walking Ekkehard Küstermann1,2, Markus Ebke3, Katja Dolge4, Natascha Lohr1, Dieter Leibfritz2, Manfred Herrmann1 1ZKW/Neuropsychologie, Universität Bremen, Bremen, Germany; 2Organische Chemie, Universität Bremen, Bremen, Germany; 3Neurologie, Klinikum Bremen-Mitte, Bremen, Germany; 4JCLLaID, Jacobs University Bremen, Bremen, Germany The steadiness of walking decreases in elderly with advancing age. This study was designed to explore changes in the activation pattern during walking. Healthy young and elderly subjects performed imaginated walking tasks while being scanned. Elderly subjects exhibited stronger and larger activations as compared to younger subjects with a marked increase in the IPL. During imaginated walking, negative BOLD signal changes were only observed in younger, but not in elderly subjects. 2014. Naming Errors and Gray Matter Structural Variations Katie McMahon1, Anna Holmes2, Shiree Heath2, Anthony Angwin3, Lindsey Nickels4, Eril McKinnon2, Sophie Van Hees2, David Copland2,3 1Centre for Magnetic Resonance, University of Queensland, Brisbane, Queensland, Australia; 2UQ Centre for Clinical Research, University of Queensland, Australia; 3School of Health and Rehabilitation Sciences, University of Queensland, Australia; 4Macquarie Centre for Cognitive Science (MACCS), Macquarie University, Sydney, NSW, Australia The frequency of naming errors increases in normal aging. In this study we examined an elderly cohort of subjects; classified their naming difficulties and correlated this with high resolution structural MRI images. Different regions were structurally correlated for reduced semantic, phonological and visual perception errors, including the inferior temporal lobe, middle temporal lobe, and occipital-parietal regions. 2015. Correlations Between Semantic Priming, Word Recognition and Gray Matter Density Katie McMahon1, Anthony Angwin2, Anna Holmes3, Shiree Heath3, Sophie Van Hees3, David Copland, 2,3 1Centre for Magnetic Resonance, University of Queensland, Brisbane, Queensland, Australia; 2School of Health and Rehabilitation Sciences, University of Queensland, Australia; 3UQ Centre for Clinical Research, University of Queensland, Australia A normal elderly cohort was examined with MRI and a lexical access/semantic priming task. The priming effect (semantically related vs unrelated prime-target pairs), and the word (semantic + unrelated response times) versus non-word targets were calculated. These variables were covaried with the individual subjects high resolution MRI images, to investigate any possible structural dependencies. Structures of areas associated with attentional and semantic priming networks were significant when compared against non-word responses, and areas of conceptual object knowledge and familiarity when compared with the priming effect. Toshiharu Nakai1, Makoto Miyakoshi1, Epifanio Bagarinao1, Chikako Nakai2, Kayako Matsuo3 1Functional Brain Imaging Lab, National Center for Geriatrics and Gerontology, Ohbu, Aichi, Japan; 2School of Health Sciences, Toyoshashi Sozo University, Toyohashi, Aichi; 3Psychology, National Taiwan University, Taipei, Taiwan The characteristics of the hemodynamic response function underlying the age-related change was investigated to estimate its contribution to the statistical evaluation of fMRI by using motor tasks. It was suggested that the neuronal demanded was augmented to support cognitive processing for motor regulation rather than motor execution itself. Augmented activation in the elderly subjects mostly depended on the increased BOLD signal amplitude between the initial and post-stimulus peaks. It will be recommended to consider the potential bias induced by the non-linear dynamics of HRF to assess the age-related change of brain activation. Jan Willem W. van der Veen1, Paul J. Carlson1, Jun Shen1 1NIH, NIMH, MAP, Bethesda, MD, United States GABA and Glx were measured in 28 volunteers using a PRESS-based two step J editing sequence. Two voxels located in the medial prefrontal cortex (MPFC) and the occipital lobe (OCC) were studied. The GABA/Cre ratio was significantly higher (P<0.001) in the OCC (0.115 +/- 0.008) than in the MPFC (0.102 +/- 0.009). Co-edited Glx/Cre ratio was significantly (P<0.001) lower in the OCC (0.0806 +/- 0.006) than in the MPFC (0.0974 +/- 0.009). Our results, combined with previously reported Cre distribution in brain, show that there are significant differences in GABA and Glx between MPFC and OCC. Developing Brain & TTS Abnormalities Hall B Thursday 13:30-15:30 Amy Louise Kotsenas1, David W. Stanley2, Dan W. Rettmann3, John D. Port1 1Dept. of Radiology, Mayo Clinic, Rochester, MN, United States; 2GE Healthcare, Proctor, MN, United States; 3GE Healthcare, Rochester, MN, United States The double inversion recovery (DIR) sequence supresses both cerebrospinal fluid and white matter signal which is of benefit in detecting subtle malformations of cortical development. Using the TI parameters from our adult DIR protocol did not provide optimum white matter signal suppression in pediatric patients as the T1 of the white matter varies with the degree of myelination. We were able to determine approximate TIwm values for use in DIR sequence to optimize the grey-white matter contrast in patients aged 1 year to 7.5 years. We were unable to optimize white matter suppression in children under 1 year of age. Peter Kochunov1, David Purdy2, Duff Davis1 1Reseach Imaging Institute, UTHSCSA, san antonio, TX, United States; 2Siemens Healthcare USA, Malvern, PA , United States Because non-human primates (NHPs) and humans share a highly orchestrated pattern of cerebral development, imaging of fetal brain maturation in NHPs provides an excellent opportunity to validate theories regarding gyrification of the cortex. Compared to human studies, structural imaging in NHPs is challenging because of the small brain size, and spatial sampling comparable to human studies (~1.0 mm3) requires brain-size-adjusted sampling volumes of ~150 microns3. Longitudinal studies of in utero NHP brain were accomplished with a true FISP isotropic 3D protocol having superior signal-to-noise ratio, low SAR, and good contrast among gray matter, white matter, CSF, and amniotic fluid. 2020. Diffusion Spectrum Tractography and Histology: Developing Connectivity in the Cat Brain Emi Takahashi1, Guangping Dai2, Ruopeng Wang2, Kenichi Ohki3, Glenn D. Rosen4, Albert M. Galaburda4, Rebecca D. Folkerth5, Van J. Wedeen2, P. Ellen Grant1,6 1Department of Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA, United States; 2Department of Radiology, Massachusetts General Hospital; 3Department of Neurobiology, Harvard Medical School; 4Department of Neurology, Beth Israel Deaconess Hospital, Harvard Medical School; 5Department of Pathology, Childrens Hospital Boston; 6Department of Radiology, Children's Hospital Boston The transient subplate (SP), located just below the immature cortex, is crucial for the formation of neuronal circuits, but it has been challenging to image abundant crossings running through the SP. Using high-resolution diffusion spectrum imaging (DSI) tractography, we successfully imaged 3-dimensional cortical/subcortical pathways in P0 (newborn), P35 (pediatric), and P100 (adult) cats and compared the findings to histology. In some regions, perpendicular to the projecting pathways, emergence of long association fibers was also imaged. These results show the potential of DSI in fixed pathological specimens at any stage of myelination to provide information on developing organization and connectivity. 2021. Diffusion MRI of in Utero Mouse Embryos Lin Zhao1, Scott E. Fraser1, J. Michael Tyszka1 1California Institute of Technology, Pasadena, CA, United States In utero MR microscopy of developing mouse embryos is complicated by maternal respiratory motion and by the general lack of tissue contrast between embryonic tissues, particularly in the CNS. We explore here the use of volumetric diffusion-weighted MR microscopy to visualize the embryonic brain in utero at later development stages. 2022. Prenatal MR Imaging of Focal Cortical Gyration Anomalies at Early Stage of Development Andrea Righini1, Cecilia Parazzini1, Chiara Doneda1, Laura Avagliano2, Filippo Arrigoni1, Mariangela Rustico1, Gaetano Bulfamante2, Fabio Triulzi1 1Radiology and Neuroradiology, Children's Hospital V. Buzzi, Milan, Italy, Italy; 2Pathology, San Paolo Hospital, Milan, Italy, Italy We report the MRI patterns of focal cortical gyration anomalies, as they appear at a very early stage of the sulcation process (when fetal brain is almost lyssencephalic). 22 cases (gestational age between 21 and 24 weeks) showed focal gyration anomalies, which could be divided in four basic patterns of cortical rim distortion: wart-like, saw-tooth, major aberrant invaginating sulucs/i, single or multiple bumps. Most of these cases presented similarities to the rat model of experimentally induced polymicrogyria. The present cohort shows how focal cortical gyration anomalies can be detected even at very early sulcation process stage 2023. Fetal Imaging with Multitransmit MR at 3.0T: Preliminary Findings Christopher G. Filippi1, Alisa Johnson2, Joshua P. Nickerson3, Betsy Sussman4, Jay Gonyea5, Trevor Andrews6 1Radiology, University of Vermont School of Medicine-Fletcher Allen Health Care, Burlington, VT, United States; 2radiology, fletcher allen health care, burlington, VT, United States; 3Radiology, Fletcher Allen Health Care, Burlington, VT, United States; 4Radiology, Fletcher Allen Health Care-University of Vermont School of Medicine, Burlington, VT, United States; 5Radiology, University of Vermont School of Medicine, Burlington, VT, United States; 6Radiology, Philips Health Care, Cleveland, OH, United States Multitransmit MR corrects B1 inhomogeneity which lessens dielectric shading, and a more uniform flip angle reduces focal SAR hot spots and allows for safe fetal MR imaging at 3.0 T for brain anomalies, and using multitransmit MR with SENSE allows for faster scan times and better signal to noise. We present 3 cases comparing 3.0T fetal MR imaging with and without multitransmit to follow-up MR imaging in the perinatal period to assess the accuracy, image quality, and clinical feasibility of multitransmit MR imaging of the fetus at 3.0T 2024. Fetal Cortex Extraction Using Subject Specific Priors Paul Aljabar1, Mellisa S. Damodaram2, Mary A. Rutherford3, Daniel Rueckert1, Joseph V. Hajnal3 1Visual Information Processing group, Department of Computing, Imperial College London, London, United Kingdom; 2 Division of Surgery, Oncology, Reproductive Biology and Anaesthetics, Imperial College London, London, United Kingdom; 3Robert Steiner MR Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Hammersmith Hospital, Imperial College London, London, United Kingdom Automatic segmentation of the cortex from fetal brain MRI has potential as a significant tool in developmental neuroscience. We developed an accurate and robust method for extracting the cortex based on creating subject specific cortical priors using label propagation from automatically produced neonatal atlases. The method was tested on 12 fetal subjects with gestational age range from 20 -30 weeks, imaged using single shot Fast Spin Echo sequences with Slice to Volume (SVR) 3D reconstruction. The method was validated against manual segmentation and found to yield a mean error of 1.15±1.03mm. Emilie ZANIN1, Jean-Philippe Ranjeva1, Sylviane Confort-Gouny1, Maxime Guye1, Danielle Denis2, Patrick J. Cozzone1, Nadine GIRARD1 1CRMBM UMR CNRS 6612, Marseille, France; 2CHU Nord, Marseille, France Objective of this study was to demonstrate the ability of DTI tractography, to assess in vivo and in utero a crucial stage of human fetal brain development: the white matter maturation. We observed that evolution of diffusion characteristics during gestation were different for cortical spinal tract, optic radiations, anterior, middle and posterior part of corpus callosum reflecting the presence of structural heterogeneity between these large WM tracts during gestation. Non-linear curve fittings of normalized longitudinal and radial water diffusivities as a function of age identify 3 different phases of maturation with specific dynamics for each WM bundle type. Peter Kochunov1, Carlos Castro2, Gerald Schatten3, David Purdy4, Duff Davis1 1Reseach Imaging Institute, UTHSCSA, san antonio, TX, United States; 2Ob / Gyn and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; 3Pittsburgh Development Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; 4Siemens Medical Solutions, Malvern, PA , United States Neonates of Old World monkeys have the longest gestational development phase among comparably sized mammals, and as a consequence, neonatal heads approach the size of the birthing canal. This can lead to cephalo-pelvic limitation, a situation in which the size of the birthing canal presents a physical limit on the size and shape of neonate during parturition. An unexpected labor provided a rare opportunity to map deformations experienced by the neonatal brain during these normal contractions. A deformation field analysis produced a 3-D array of 3-D displacement vectors, showing dramatic regional deformation of the fetal brain during normal labor. 2027. Mapping the Development of the Human Connectome Patric Hagmann1, Olaf Sporns2, Stephan Gerhard3, Rudolph Pienaar4,5, Jean-Philippe Thiran3, Leila Cammoun3, Neel Madan6, P Ellen Grant4,5 1Department of Radiology, CHUV-UNIL, Lausanne, VD, Switzerland; 2Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, United States; 3Signal Processing Laboratory 5, EPFL, Lausanne, VD, Switzerland; 4Division of Newborn Medicine and Department of Radiology, Childrens Hospital Boston, Boston, MA, United States; 5Athinoula A. Martinos Center for Biomedical Imaging, MGH-Harvard, Boston, MA, United States; 6Department of Radiology, MGH-Harvard, Boston, MA, United States From birth to early adulthood the brain undergoes dramatic modifications resulting in network development and optimization. In the present study we investigate the development of the human connectome but measuring myelination trajectories of individual connections over the entire brain structural network using high b-value diffusion imaging and tractography. We found significant changes in several network measures that support increased integration and efficiency. We also observe that the network doesnt myelinate at a uniform rate but with different myelination speeds dependant on the type of cortex. Peter Kochunov1, Carlos Castro2, David Purdy3, Yi Zhang1, Duff Davis1 1Reseach Imaging Institute, UTHSCSA, san antonio, TX, United States; 2Ob / Gyn and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; 3Siemens Medical Solutions, Malvern, PA , United States Primary gyrogenesis is a poorly-understood developmental process that transforms the lissencephalic cortex of a maturing mammalian brain toward its mature, gyrencephalic state by sculpting an intricate pattern of folds (gyri) and burrows (sulci). A novel in utero MRI protocol developed specifically for high-resolution imaging of fetal brain was used for precise tracking of global and regional gyrification in fetuses of baboons, information that would otherwise be difficult to obtain. These studies revealed a disparity in the growth rates of revealed a disparity of the growth rates in sulcal length and depth. 2029. Central and Cortical Gray Mater Segmentation of Magnetic Resonance Images of the Fetal Brain Meritxell Bach Cuadra1, Marie Schaer2, Gabriele Bonano1, Anouk André1, Laurent Guibaud3, Stephan Eliez2, Jean-Philippe Thiran1 1Signal Processing Laboratory (LTS5), Ecole Polytechnique Federale de Lausanne (EPFL), Ecublens, Vaud, Switzerland; 2Service Médico-Pédagogique, Psychiatry Department, University of Geneva School of Medicine, Switzerland; 3Imagerie pédiatrique et ftale, Hōpital Debrousse, Lyon, France In this work we present our methodology to segment central (basal ganglia) and cortical gray mater of brain in magnetic resonance fetal imaging. This is a key step in the study of early human brain development. The results for basal ganglia segmentation are quantitatively validated in 4 cases from 29 to 32 gestational weeks. Cortical brain surface is evaluated qualitatively in a case study. Our efforts are now in testing such approach on a wider range of gestational ages that we will include in the final version of this work and studying as well its generalization to different scanners and different type of MRI sequences. 2030. Correction Strategy for Infants Diffusion-Weighted Images Corrupted with Motion Jessica Dubois1,2, Ghislaine Dehaene-Lambertz1,3, Lucie Hertz-Pannier2,4, Giovanna Santoro1, Jean-Franēois Mangin, 3,5, Cyril Poupon, 3,5 1U562, Inserm, Gif-sur-Yvette, France; 2LBIOM, CEA, Gif-sur-Yvette, France; 3IFR49, Paris, France; 4U663, Inserm, Paris, France; 5LNAO, CEA, Gif-sur-Yvette, France Diffusion Tensor Imaging (DTI) offers the possibility to study the developing white matter non-invasively. However, diffusion-weighted images obtained in non-sedated infants are often corrupted with motion artifacts. We propose a post-processing methodology which takes advantage of the high diffusion orientation count and corrects these images before the computation of diffusion maps. The strategy relies on three successive steps: two steps of correction of corrupted slices (using decomposition on a spherical harmonics basis), separated by a step of 3D motion registration. This approach was validated on DTI data from 15 infants, by reliably evaluating the corpus callosum maturation with tractography-based quantification. Jeff D. Winter1, Jelena Lukovic1, Andrea Kassner1,2 1Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Medical Imaging, University of Toronto, Toronto, Ontario, Canada In this study, we explored the potential of the swine brain for neurodevelopmental imaging by MRI characterization of structural and microstructural changes. We collected anatomical and diffusion tensor images from 11 juvenile (1-12 wk) pigs. A significant positive logarithmic relationship existed between body weight and tissue brain volumes, as well as the surface folding index, a measure of cortical folding. Similar to humans, fractional anisotropy exhibited a logarithmic increase with body weight for all regions investigated. No mean diffusivity changes existed. These results suggest the swine brain may provide an informative model for translational studies of early human brain development. Carola van Pul1,2, Britt van Kooij3, Gijs Hoskam4, Linda de Vries3, Manon Benders3, Anna Vilanova4, Floris Groenendaal3 1Clinical Physics, Maxima Medical Center, Veldhoven, Noord-Brabant, Netherlands; 2School of Medical Physics and Engineering, Eindhoven University of Technology, Eindhoven, Noord-Brabant, Netherlands; 3Neonatology, Wilhemina Children's Hospital, Utrecht, Netherlands; 4Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Noord-Brabant, Netherlands We studied 92 prematurely born neonates (<31 weeks) at term equivalent age using quantitative Fiber Tracking (FT), generated on 3.0T MRI. Patients were divided into three groups, based on scoring of the conventional MRIs. Using a general linear model, the effects of factor (group) and variables (gestational age, birth weight and head circumference) were tested. For the FA and ADC in corpus callosum fiber bundle, a significant relation with MR group was observed. Furthermore, for the corpus callosum, volume, Cl and length depended significantly on the gestational age, suggesting an influence of age at birth on brain maturation. 2033. High Angular Resolution Diffusion Imaging (HARDI) Analysis of the Motor Pathway in Infants Jeffrey I. Berman1, Sonia L. Bonifacio2, Roland G. Henry1, Donna M. Ferriero2,3, Hannah C. Glass2, A James Barkovich1, Duan Xu1 1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States; 2Pediatrics, University of California San Francisco, San Francisco, CA, United States; 3Neurology, University of California San Francisco, San Francisco, CA, United States High angular resolution diffusion imaging (HARDI) was used to examine white matter microstructre in 3 and 6 month old infants with a history of birth asphyxia. Residual-bootstrap probabilistic q-ball tractography was used to delineate the motor pathway. As in adults, the motor tract intersects other white matter tracts in the centrum semiovale and q-ball fiber tractography could traverse these regions. Diffusion parameters were measured in the 3D region defined by fiber tractography. This study demonstrates the feasibility of using in-vivo HARDI to discriminate complex white matter architecture in infants within a reasonable exam time. 2034. Vein Quantification of SWI in Infants with Hypoxic-Ischemic Encephalopathy (HIE) Samuel Barnes1,2, Chantal Lunderville2, Gene Kitamura2, Stephen Ashwal2, Andre Obenaus2 1Wayne State University, Detroit, MI, United States; 2Loma Linda University, Loma Linda, CA, United States The use of susceptibility weighted imaging (SWI) in hypoxic-ischemic encephalopathy (HIE) can give additional information about the varying amounts of deoxyhemoglobin in cerebral veins as an indicator of metabolic stress. Abnormal levels of deoxyhemoglobin (low or high) are correlated with poor clinical outcome. This work compares different qualitative and quantitative measures of venous visibility as an indicator of deoxyhemoglobin levels and how it correlates with clinical outcome. Jonathan D. Clayden1, Sebastian Jentschke1, Monica Muńoz1, Janine Cooper1, Tina Banks2, Faraneh Vargha-Khadem1, Chris A. Clark1 1Institute of Child Health, University College London, London, Greater London, United Kingdom; 2Radiology Department, Great Ormond Street Hospital, London, Greater London, United Kingdom There is evidence for various changes in white matter microstructure during development, in some cases specific to certain pathways. In this study we report what we believe to be the first evidence of gender differences in the rates of change of diffusion MRI parameters, in a healthy group of 8-17 year old children. Samantha J. Holdsworth1, Kristen Yeom1, Stefan Skare1, Patrick David Barnes1, Roland Bammer1 1Radiology, Stanford University, Palo Alto, CA, United States Readout-segmented (RS)-EPI has been suggested as an alternative approach to EPI for high resolution diffusion-weighted imaging (DWI) with reduced distortions. Here we implemented GRAPPA-accelerated RS-EPI DWI on 35 pediatric patients at 3T. We compared these images with standard accelerated (ASSET) EPI DWI used routinely for pediatric clinical studies. Images were categorized by resolution, distortion level, SNR, lesion conspicuity, and diagnostic confidence. RS-EPI out-performed ASSET EPI and demonstrated that it may be a useful method for DWI for evaluating lesions such as hypoxic-ischemic brain injury, diffuse axonal injury, tumors, dermoid/epidermoid, and skull base/orbital pathology. Michael Dayan1, Chris A. Clark1 1Radiology & Physics, UCL Institute of Child Health, London, United Kingdom The optic radiation (OR) is a component of the visual pathway assumed to mature before 3 years old. This study aimed at evaluating diffusion tensor (DT) metrics within this tract, notably fractional anisotropy (FA) and radial diffusivity (RD), as a function of age, hemisphere and gender in children aged from 7 to 18. DT probabilistic tractography based on 10000 iterations was carried out for this purpose. A one sample t-test demonstrated a hemispheric dependence for RD (p < 0.01) but not for FA (p > 0.96). A multiple regression analysis did not show any gender effect for any DT indices. A significant age dependence was found for FA (p < 0.001) and RD (p < 0.04). These findings suggest an age-related effect from 7 to 18 years well after the OR is myelin mature, which suggests that maturational and/or developmental changes occur in the OR long after myelination. 2038. Anatomical Assessment of the Optic Radiation in Children with Probabilistic Tractography Michael Dayan1, Chris A. Clark1 1Radiology & Physics, UCL Institute of Child Health, London, United Kingdom Temporal lobectomy, a surgical procedure notably carried out in children affected by intractable epilepsy, may be associated with visual field defects if the optic radiation (OR) is damaged. The lack of data in children on the spatial dimensions and location of this pathway with highly variable anterior aspect, Meyers loop (ML), lead us to reconstruct the OR in children in the age range 7 to 18 with probabilistic tractography. The segmentation was assessed by computing two reference anatomical distances, the distance from ML to the temporal pole (ML-TP) and to the occipital pole (ML-OP), and comparing them with other tractography and dissection studies in adults. A one sample t-test showed a hemispheric dependence for ML-TP and ML-OP (p < 0.02) and a multiple regression analysis demonstrated a gender dependence but no age effect. The distances reported in this study were similar to tractography and dissection studies in adults. These data and the statistically significant dependence on gender and hemisphere are envisaged to be relevant when considering neurosurgical planning for temporal lobectomy in children. Colleen Dockstader1,2, William Gaetz3, Conrad Rockel1, Donald Mabbott1 1Dept of Psychology/Division of Haemotology/Oncology, The Hospital for Sick Children, Toronto, ON, Canada; 2Dept of Anaesthesia and Pain Medicine, The Hospital for Sick Children, Toronto, ON, Canada; 3Biomagnetic Imaging Laboratory, Children's Hospital of Phiadelphia, Philadelphia, PA, United States We investigated age-related changes in the latency of the P100m visual response in occipital cortex and the biophysical properties of white matter in eleven healthy children to determine the impact of white matter growth on the maturation of neuronal signaling. Using TBSS, we found a significant relationship between FA and P100m latency in the dorsal processing stream. The latency of the P100m was inversely related to FA and positively related to age. Our findings suggest that simple measures of evoked latency on a visuomotor-attention task reflects dorsal stream integrity that is related to stage of cortical maturation in healthy children. 2040. Precision and Accuracy of Arterial Spin Labeling Perfusion MRI in the Pediatric Population Varsha Jain1, Mariel Giannetta1, Michael Langham1, Sharon Xie1, Daniel Licht1, Joan Giannetta1, Timothy Roberts2, John Detre1, Hallam Hurt2, Felix Wehrli1, Jiongjiong Wang1 1University of Pennsylvania, Philadelphia, PA, United States; 2Children's Hospital of Philadelphia, Philadelphia, PA, United States We evaluated the precision and accuracy of absolute CBF measurements using two arterial spin labeling (ASL) techniques, pulsed ASL (PASL) and pseudo-continuous ASL (pCASL) in a typical developing cohort of 18 healthy children 7 to 17 years old. Longitudinal reproducibility (precision) was assessed by repeated scans 2-4 weeks apart, while accuracy was assessed by comparison with total blood flow volume measured by phase-contrast (PC) MRI at the labeling plane. The results demonstrate excellent precision (ICC=0.62) and accuracy (ICC=0.77) of quantitative CBF measured by pCASL. 2041. Optimisation of Fast Quantitative T2 Imaging of the Premature Brain: A Fantom Study Laetitia Maurin1,2, Dominique Sirinelli2, Jean Philippe Cottier, 1,3, Laurent Barantin1,2 1NMR Department, UMR Inserm U 930 - CNRS ERL 3106 - Université Franēois Rabelais de Tours, TOURS, France; 2Pediatric Radiology, CHRU de TOURS, TOURS, France; 3Neuroradiology, CHRU de TOURS, TOURS, France The aim of this work was to optimize and compare different T2 sequences so we could find one suitable for quantitative study of premature newborn brain. Four sequences were tested. After mathematical correction, T2 values found for each sequence were comparable to those calculated by the reference sequence. We choose the SSFSE sequence for premature T2 maps due to its duration. This sequence was optimized in order to decrease final acquisition time. This work allowed us to create a sequence, SSFSE 4 echoes, reliable and reproducible to calculate pediatric neurologic T2 maps with duration suitable for routine clinical practice. Lajos R. Kozak1, Gįbor Rudas1, Zoltįn Vidnyįnszky1,2, Zoltįn Nagy3 1MR Research Center, Semmelweis University, Budapest, Hungary; 2Neurobionics Research Group, Hungarian Academy of Sciences - Pįzmįny Péter Catholic University - Semmelweis University, Budapest, Hungary; 3Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom The feasibility of cardiac triggered diffusion data acquisition in a pediatric population was investigated. Data was collected with and without cardiac triggering either along the z gradient direction and then subjected to bootstrap statistics (3 subjects) or in 15 non-collinear directions and fitted to a tensor model (3 subjects). We found that cardiac triggering decreases the variability in the data without a significant increase in acquisition time in the investigated pediatric population. 2043. RF Shield Coat for Mother to Be in the Magnet with Her Child. Shin-ichi Urayama1, Naozo Sugimoto2, Hidenao Fukuyama1 1Human Brain Research Center, Kyoto University, Kyoto, Japan; 2School of Health Sciences, Faculty of Medicine, Kyoto University, Kyoto, Japan For pediatric imaging, accompanying scan, in which an accompanying person wearing an RF shield coat is in the magnet with the child, was examined. Although there are two problems, peripheral nerve stimulation and SNR reduction, this technique is proved to be a feasible solution to avoid risks in pediatric imaging. Live Eikenes1, Jon Skranes2, Ann-Mari Brubakk2, Asta Håberg3 1Department of circulation and medical imaging, Norwegian University of Science and Technology, Trondheim, Norway; 2Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway; 3Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway Preterm birth with very low birth weight (VLBW, ≤ 1500 g) is associated with reduced white matter integrity and connectivity in childhood and adolescence. These changes in white matter are correlated to motor, sensory and neuropsychological impairments. This study demonstrates that preterm birth with VLBW results in significant and long-term irreversible changes in white matter microstructure that may interfere with neuropsychological functioning. Lower birth weight and perinatal problems requiring prolonged treatment on mechanical ventilator and/or intensive care have permanent negative effects on white matter integrity. Live Eikenes1, Gro Lųhaugen2, Kjerstin Bjųrlykke2, Ann-Mari Brubakk2, Jon Skranes2, Asta Håberg3 1Department of circulation and medical imaging, Norwegian University of Science and Technology, Trondheim, Norway; 2Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway; 3Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway Perinatal brain injury caused by very preterm birth with very low birth weight (VLBW, ≤ 1500 g) is associated with changes in white matter integrity and connectivity, and to a variety of neurodevelopmental problems including cognitive impairments and visual perceptual deficits in childhood and adolescence. Widespread correlations between fractional anisotropy and total IQ and visual perception scores was detected in a young adult VLBW group, demonstrating the pervasive nature of the reduction in cognition and perception in this group. The results demonstrate that the neuroimpairments persist into adulthood. Lindsey A. Leigland1, Christopher D. Kroenke1 1Oregon Health & Science University, Portland, OR, United States Throughout the human gestational period, morphological differentiation of cortical neurons and glial cells cause water diffusion anisotropy within the developing cerebral cortex to decrease with age. Herein, the loss of cortical fractional anisotropy (FA) reported by several research groups in five different species is referenced against a systematic comparative study of the timing of several milestones in brain development. It is found that, when the loss of cortical FA is approximated as an exponential decay with age, the time constant reflecting the rate of FA change is in agreement with independent estimates of the rate in which developmental events occur. Rob Lipinski1, Chihwa Song2, Jerry Gipp3, Wade Bushman3, Ian Rowland4 1Bowles Center for Alcohol Research, University of North Carolina, Chapel Hill, NC, United States; 2Medical Physics, University of Wisconsin, Madison, WI, United States; 3Urology Department, University of Wisconsin, Madison, WI, United States; 4Department of Radiology, University of Wisconsin, Madison, WI, United States In utero Hedgehog (Hh) signaling antagonist exposure causes a spectrum of birth defects including holoprosencephaly (HPE) and cleft lip and palate (CLP). High resolution MRI and standard histological methodologies were used to characterize the CNS phenotype of GD16.5 mouse fetuses exposed to Hh antagonists. HPE fetuses exhibited incompletely separated cerebral hemispheres and complete pituitary and olfactory bulb agenesis. Those with CLP exhibited olfactory bulb hypoplasia and anterior pituitary aplasia. These results demonstrate phenotypic fidelity of the mouse model to known clinical phenotypes and highlight subtle CNS abnormalities as are expected to occur in a subset of clinical CLP populations. David Price1, Giles Simon Kendall2, Alan Bainbridge1, Samantha Johnson2, Cornelia Hagmann2, Roxanna Gunny3, Xavier Golay4, Ernest B. Cady1, Nicola Jane Robertson2, Enrico De Vita5 1Medical Physics & Bio-Engineering, UCL Hospitals NHS Foundation Trust, London, United Kingdom; 2Academic Neonatology, EGA UCL Institute for Women's Health, London, United Kingdom; 3Neuroradiology, Great Ormond Street Hospital for Children; 4Institute of Neurology, University College London; 5Lysholm Department of Neuroradiology, UCL Hospitals NHS Foundation Trust, London, United Kingdom Infants born prematurely have a higher incidence of neurodevelopmental disorders. Diffuse white matter injury is the commonest MR finding in preterm infants, and has been described qualitatively and quantitatively; the clinical correlate of diffuse white matter injury is currently unknown. In the current study raised Cho/Cr and Lac/Cr, and reduced Naa/Cho were significantly associated with composite motor outcome at 12 months corrected age, and accounted for by significant associations with gross motor development. The raised choline could be attributed to delayed myelination, astrogliosis; the raised Lac/Cr suggests impaired oxidative phosphorylation, and the reduced Naa is in keeping with neuronal loss.
2049. Developmental Coordination Disorder: A Voxel-Based MRI Study of Neural Correlates William Lloyd1, Mark Mon-Williams2, Gordon D. Waiter3, Justin H. G. Williams4 1Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, AB25 2ZD, United Kingdom; 2Institute of Physiological Sciences, University of Leeds, Leeds, United Kingdom; 3Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, United Kingdom; 4Department of Child Health, University of Aberdeen, Aberdeen, United Kingdom Developmental Coordination Disorder (DCD) is a common childhood disease that affects roughly 6% of the population and can have a long-term impact for sufferers. The role of specific brain areas in DCD has long been postulated from behavioural studies, yet the underlying aetiology of the disease remains poorly understood. We used MRI to investigate correlations between regional brain volumes and psychometric measures in a DCD population. The research presented here provides, to the best of our knowledge, the first structural neuroimaging evidence of the role of regional brain structure in DCD. 2050. Diffusion Tensor Imaging Study of Adolescents with Spina Bifida Xiawei Ou1,2, John J. Hall3, Charles M. Glasier1,2, Jeffrey H. Snow3 1Radiology Department, Arkansas Children's Hospital, Little Rock, AR, United States; 2Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, AR, United States; 3Psychology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, United States Diffusion tensor imaging study was performed on adolescents with spina bifida and age matched controls. The study was aimed to detect the abnormalities in cerebral white matter microstructures in spina bifida patients. We found significantly elevated mean diffusivity of water in major white matter tracts, as well as decreased fractional anisotropy in the corpus callosum and callosal fibers. In addition, significant changes of white matter DTI parameters were observed in the cerebral hemisphere with ventricular shunt in spina bifida patients. Our study provides useful information of brain development affected by spina bifida. Napapon Sailasuta1, Andrea L. Gropman2, Kent Harris1, Osama Abulseoud3, Brian D. Ross1,4 1Clinical MR Spectroscopy, Huntington Medical Research Institutes, Pasadena, CA, United States; 2Neurology, Children's National Medical Center, Washington D.C., United States; 3University of Southern California, Keck School of Medicine, Los Angeles, CA, United States; 4Rudi Schulte Research Institute, Santa Barbara , CA, United States Despite effective treatment of hyperammonemia, children and adult survivors of ornithine transcarbamlyase deficiency (OTCD) a frequent enzyme defect of the hepatic urea cycle, exhibit a wide variety of neurological, neuropsychological, neuroimaging and neurochemical abnormalities. Most recently, in addition to proton MRS abnormalities o sub-clinical hepatic encephalopathy, residual deficits in glutamate neurotransmission have been identified by non-invasive 13C MRS studies after loading tests with 1-13C and 2-13C glucose. The results point to a hitherto unrecognized defect in cerebral glucose metabolism. Successful therapies of this new lesion may improve long term neurological outcome for this and other defects of urea synthesis. Maria Fatima Falangola1,2, Vitria Adisetiyo1, Wende R. Gelb1, Jens H. Jensen1, Caixia Hu1, Ali Tabesh1, Francisco X. Castellanos3, Adriana DiMartino3, Joseph A. Helpern1,2 1Radiology, New York University Langone Medical Center, New York, NY, United States; 2Center for Advanced Brain Imaging, Nathan Kline Institute, Orangeburg, NY, United States; 3Child Study Center, New York University Langone Medical Center, New York, NY, United States Since the neuroanatomical basis of attention deficit-hyperactivity disorder (ADHD) is postulated to involve the frontal cortical-basal ganglia-thalamic-cerebellar circuits, we decided to examine the microstructural integrity of the thalamus in adolescents with ADHD using diffusion MRI, including a new technique called diffusional kurtosis imaging (DKI). We report that for a typically developing adolescent (12-18 yr), there are age-related diffusion changes in the thalamus, but no diffusion changes in the ADHD group, which suggest that there may be a difference in the trajectories of structural development in the thalamus between typically developing and ADHD adolescents.
2053. Cerebellar Vermis Impairment in Children Treated for Brain Malignancies Alena Horska1, Ashley LaClair2, Mona Mohamed1, Carolyn T. Wells3, Todd McNutt1, Moody Wharam1, E Mark Mahone4, Wendy Kates2 1Johns Hopkins University, Baltimore, MD, United States; 2SUNY Upstate Medical University, Syracuse, NY, United States; 3Children's National Medical Center, Rockville, MD, United States; 4Kennedy Krieger Institute, Baltimore, MD, United States The goal of this prospective longitudinal study in children receiving brain radiation involving the cerebellum was to evaluate vermal volumes and performance on neuropsychological tests associated with cerebellar function. In patients, lower mean vermal volumes and impaired performance on visual-spatial and fine motor tasks were detected at baseline. At 6-months post-radiation, further decrease in vermal volumes was detected in medulloblastoma patients; the vermal volumes decrease was not associated with reduction in neuropsychological performance compared to baseline. Regression analyses of the 6-months follow-up data from all subjects revealed better performance on the Purdue Pegboard tests with larger vermal volumes. 2054. Susceptibility-Weighted Imaging in Pediatric Epilepsy Masahiro Ida1, Hisashi Yoshizawa1, Shunsuke Sugawara1, Yuko Kubo1, Keiko Hino1, Naoya Yorozu1 1Department of Radiology, Tokyo Metropolitan Ebara Hospital, Tokyo, Japan Susceptibility-weighted imaging (SWI) exploits phase shift itself to enhance contrast caused by the susceptibility differences between tissues. SWI provides high-spatial resolution, blood-oxygen-dependent contrast without requiring contrast media. We present two pediatric patients who showed prominent cortical veins with marked hypointensity on SWI in the acute stage after onset of generalized seizure. SWI findings reflect transient misery perfusion secondary to hyperexcitation in status epilpticus. SWI directly detect impaired oxygen metabolism caused by increased oxygen demand of the cerebral tissue in pediatric patients with epileptic seizures. SWI has the possibility to diagnose acute postictal encephalopathy, before cytotoxic edema occurs on DWI. Hyeon Tae Jeong1, Jinna Kim , Hyeon Seok Choi, Eun Soo Kim, Seung-Koo Lee 1Department of Radiology, Yonsei University College of Medicine, Seoul, 250 Seongsanno, Seodaemun-gu, Korea, Republic of The purpose of this study is to evaluate the clinical relevance to FA measurement in white matter suffering from decreased perfusion in moyamoya disease, through the correlation between FA value and perfusion MRI. In the areas of chronic hypoperfusion in Moyamoya disease, FA was decreased significantly although overt infarct was not demonstrated. Diffusion tensor imaging can be used in the assessment of intergrity of white matter suffering from chronic ischemia. 2056. Measurement of Brain Water in Children During and After Treatment for Diabetic Ketoacidosis Michael H. Buonocore1, Sandra L. Wootton-Gorges2, Nathan Kuppermann3, Ryan Caltagirone, Nicole S. Glaser 1Radiology, UC Davis Imaging Research Center, Sacramento, CA, United States; 2Radiology, UC Davis Medical Center, Sacramento, CA, United States; 3Emergency Medicine and Pediatrics, UC Davis Medical Center, Sacramento, CA, United States The purpose of this study was to measure brain water in children undergoing treatment for DKA to assess cerebral edema. Brain water was measured on a 3T system using FSPGR scans with five different flip angles, followed by non-linear curve fitting to derive proton density (M0) maps, and calibrating regional M0 map values with the values from 100% water reference vials placed within the imaged volume. Results from seven children suggest that regional brain water is elevated early in the course of treatment, confirming a degree of cerebral edema. Edema increases during the course of treatment with fluids and insulin, and then resolves after the child recovers. Jeong-Won Jeong1,2, Michael Behen1,2, Piti Sinsoongsud1,2, Otto Muzik, 2,3, Benjamin Wilson1,2, Harry T. Chugani, 2,3 1Pediatrics and Neurology, Wayne State University, Detroit, MI, United States; 2PET center, Children's Hospital of Michigan, Detroit, MI, United States; 3Pediatrics, Neurology, and Radiology, Wayne State University, Detroit, MI, United States A previous 18FDG-PET study revealed that children with histories of institutional rearing showed significantly decreased glucose metabolism in neumerous brain regions. Dysfunction in these regions may result from severe stress of early deprivation. This study presents an atlas-based analysis to assess specific volumetric changes in predefined brain regions of the children with histories of early deprivation and examines associations between regional findings and cognitive, socioemotional, and behavioral difficulties that commonly are observed in the orphans. Significant bilateral volume reduction in grey-white matter was observed in the orphan group. It was highly correlated with their externalizing behavioral deficit and perceptual functioning. Jeong-Won Jeong1,2, Senthil Sundaram1,2, Benjamin Wilson1,2, Harry T. Chugani, 2,3 1Pediatrics and Neurology, Wayne State University, Detroit, MI, United States; 2PET center, Children's Hospital of Michigan, Detroit, MI, United States; 3Pediatrics, Neurology, and Radiology, Wayne State University, Detroit, MI, United States Angelman syndrome (AS) is a genetic disorder characterized by mental retardation, speech impairment, and gait apraxia. Speech impairment is universal but severity differs, which can be characterized by myelination delay or deficits of white matter associated with language production and conception, especially of arcuate fasciculus (AF) bridging Broca”Æs and Wernicke”Æs areas. This study presents new DT-MRI methodology to identify aberrant shapes of arcuate fibers and quantify abnormal tracts in terms of their geometry. We found that the AF of AS patients have steeper lateral-curvatures cauisng them not to reach Wernicke”Æ area and also their FA values were significantly reduced. Lidia M. Nagae1, John Dell1, Robert A. Zimmerman1, Timothy P.L. Roberts1 1Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States The superior longitudinal fasciculus (SLF), related to language, was evaluated using diffusion tensor imaging in autistic patients, in particular in a specific group of autistics patients with language impairment (ASD/+LI), compared to autistic patients without language impairment (ASD/-LI), and typically developing children and adolescents (TD). Mean diffusivity, along with axial diffusivity were found to be increased in ASD/+LI when compared to TD. Intermediate values were obtained in ASD/-LI. These findings might reflect reported microstructural abnormalities of the brain, thought to be related to immature white matter development. Noriko Sato1, Tomoyuki Takahashi, Miho Ota, Nakata Yasuhiro, Masayuki Sasaki 1National Center Hospital of Neurology and Psychiatry, Kodaira, Tokyo, Japan Asymmetrical fiber tract distributions passing through the corpus callosum in hemimegalencephaly patients. Rajesh Kumar1, Paul M. Macey2,3, Mary A. Woo2, Ronald M. Harper1,3 1Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States; 2School of Nursing, UCLA, Los Angeles, CA, United States; 3Brain Research Institute, UCLA, Los Angeles, CA, United States Congenital central hypoventilation syndrome (CCHS) patients show respiratory and autonomic deficits likely resulting from PHOX2B mutations affecting autonomic development, or from hypoxic injury. We evaluated axial- and radial-diffusivity, indicating axonal and myelin deficits, respectively, in rostral brain of CCHS. Increased radial-diffusivity emerged in the corona-radiata, internal-capsule, and corpus-callosum, suggesting myelin injury. Axial-diffusivity changes appeared in the thalamus, internal-capsule, corona-radiate, occipital, and temporal lobes, suggesting axonal deficits. Increased axial- and radial-diffusivity appeared in basal forebrain, limbic, occipital, and temporal areas, indicating myelin and axonal deficits. The mechanisms of brain injury are unknown, but likely include both hypoxic and genetic processes. Jesu Christopher Joseph1, Anton Eicher2, Christopher Warton1, Sandra W Jacobson3, Joseph L Jacobson3, Christopher D Molteno, Patrick Marais2, Ernesta M Meintjes1 1Human Biology, University of Cape Town, Cape Town, Western Cape, South Africa; 2Computer Science, University of Cape Town, Cape Town, Western Cape, South Africa; 3Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, United States The main objective of this work is to assess the shape variations of the hippocampus structure between control and FAS affected children. For this High-resolution structural MRI images were acquired of 12 children aged 9-12 years on a 3T Siemens Allegra Scanner (6 controls and 6 FAS). Hippocampi were manually delineated. The entire structure of the hippocampus was divided into three regions, namely head, body and tail. A point distribution model, which represents the mean geometry of a shape using landmark points, was used to capture the true geometry of the hippocampus. Approximately 2366 landmark points were used. Principal Component Analysis (PCA) was used to study correlations of movement between groups of landmark points among the control children who were used as the training set and to assess the geometric variations between the healthy and exposed subjects. 2063. A Realistic Model of Brain Tissue in Case of Hydrocephalus: Application of MRI, DTI and MRE Kamal Shahim1, Ralph Sinkus2, Jean-Marie Drezet1, Shahan Momjian3, jean-francois Molinari4 1LSMX, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland; 2Laboratoire Ondes et Acoustique, ESPCI, Paris, France; 3University Hospitals of Geneva and University of Geneva, Switzerland; 4LSMS, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Vaud, Switzerland Hydrocephalus is a cerebral disease wherein the brain ventricles dilate and the parenchyma is stressed. In order to study this condition, a finite element model is built using the geometries of the ventricles and the skull measured by MRI. DTI is used to establish the fiber direction and the local frame. Indeed, elasticity data based on MRE is incorporated into the constitutive equation. The brain parenchyma is modeled as a porous medium. Under an applied pressure gradient, Isotropic and Transverse Isotropic models are tested and compared together. The transmission of the applied pressure is substantially influenced by the anisotropy and inhomogeneity of brain parenchyma. 2064. Abnormal Brain Tissue Sodium Metabolism on MRI After Cardiac Arrest in Children Ericka L. Fink1,2, Patrick M. Kochanek1,2, Ashok Panigrahy3, Fernando E. Boada4,5 1Critical Care Medicine, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States; 2Safar Center for Resuscitation Research, Pittsburgh, PA, United States; 3Radiology, Children's Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States; 4Radiology, UPMC, Pittsburgh, PA, United States; 5Magnetic Resonance Research Center, Pittsburgh, PA, United States In two children with cardiac arrest, tissue sodium concentration was increased in regions of the brain that are most vulnerable to hypoxia-ischemia and reperfusion (basal ganglia and occipitoparietal cortex), representing prolonged or delayed deranged brain tissue Na metabolism. 2065. Diffusional Kurtosis Imaging Assessment of Tuberous Sclerosis Complex Vitria Adisetiyo1, Sarah S. Milla2, Howard Weiner3, Caixia Hu2, Ali Tabesh2, Jens H. Jensen1,2, Joseph A. Helpern1,2 1Neuroscience and Physiology, New York University School of Medicine, New York, NY, United States; 2Radiology, New York University School of Medicine, New York, NY, United States; 3Neurosurgery, New York University School of Medicine, New York, NY, United States Tuberous Sclerosis Complex (TSC) is a rare genetic disease that manifests in the CNS as cortical/subcortical tuber lesions consisting of abnormal dysplastic neurons. Tubers are presumed to contribute to epileptogenesis and to developmental delays in TSC. Given several reports of silent tubers with active surrounding perilesion tissue, we applied Diffusional Kurtosis Imaging (DKI) to quantitatively characterize the microstructure of tubers as compared to surrounding perilesion and normal appearing contralateral tissue in TSC patients aged 2-10 years and age-matched controls. Region of interest analysis found that only tubers are associated with significant increase in diffusivity and substantial decrease in microstructural heterogeneity. Peter Kochunov1, Carlos Castro2, Gerald Schatten3, David Purdy4, Hsiao-Ying Wey1, Duff Davis1 1Reseach Imaging Institute, UTHSCSA, san antonio, TX, United States; 2Ob / Gyn and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; 3Pittsburgh Development Center, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; 4Siemens Healthcare USA, Malvern, PA , United States While the teratogenic properties of alcohol are well known, the mechanisms by which alcohol-induced damage is produced in the CNS are still largely unknown. We present findings of changes in dynamic susceptibility contrast (DSC) in fetal brain of a non-human primate (baboon) during a protocol designed to approximate a binge drinking episode. Signal changes in the brain and uterus/placenta were compared using a pulse sequence protocol with high temporal and spatial resolution, showing that gadodiamide entered fetal cerebral circulation following alcohol administration. Multiple Sclerosis Hall B Monday 14:00-16:00 2067. 7 Tesla 3D-FLAIR and 3D-DIR: High Sensitivity in Cortical Regions in Multiple Sclerosis Wolter L. de Graaf1, F. Visser2,3, M. P. Wattjes1, J. Geurts4, P. Pouwels5, C. H. Polman6, F. Barkhof1, P. R. Luijten2, J. A. Castelijns1 1Radiology, VU University Medical Center, Amsterdam, Netherlands; 2Image Science Institute, University Medical Center Utrecht, Utrecht, Netherlands; 3PHILIPS Healthcare; 4Pathology, VU University Medical Center, Amsterdam, Netherlands; 5Physics and Medical Technology, VU University Medical Center, Amsterdam, Netherlands; 6Neurology, VU University Medical Center, Amsterdam, Netherlands MR diagnostics in Multiple Sclerosis have benefited from sequences like fluid attenuated inversion recovery (FLAIR) and double inversion recovery (DIR), that increase sensitivity especially in cortical regions. We demonstrate use of 3D (isotropic) FLAIR, DIR and T1-weighted clinically feasible imaging at 7 Tesla. Images were read for the number of lesions visible in the regular classifications for the several sequences. Results were also compared with images obtained from the same patients at 3 Tesla. A large sensitivity increase especially in cortical regions was found at 7 Tesla for all 3D sequences. 3D-FLAIR however, proofed to be the most sensitive. 2068. 3D Magnetization Prepared Double Inversion Recovery (3D MP-DIR) at 7 Tesla Frederik Visser1,2, Jaco J M Zwanenburg1, Wolter L. de Graaf3, J A. Castelijns3, Peter R. Luijten1 1UMC, Utrecht, Netherlands; 2PHILIPS Healthcare; 3VU UMC Amsterdam Dedicated magnetization preparation pre-pulses (MP) have been designed to acquire high resolution 3D DIR images covering the whole brain at 7-Tesla.The ability to detect sub-millimeter cortical and/or sub cortical lesions has great potential for future clinical studies. 2069. Cortical Lesions in MS: Assessment at 7T Kathrine T. Bluestein1, Cherian Renil Zachariah1, Steffen Sammet1, Devin Elizabeth Prior1, David Pitt2, Aaron Boster2, Amir Abduljalil1, Michael V. Knopp1, Petra Schmalbrock1 1Department of Radiology, The Ohio State University, Columbus, OH, United States; 2Department of Neurology, The Ohio State University, Columbus, OH, United States Assessment of cortical lesions in MS is of significant interest, because correlation of conventional MRI with clinical findings is limited. However, detection of cortical lesions has been hampered by their small size and low contrast. In this study, we assessed cortical lesion detection in 7 MS patients and healthy controls at 7T using high resolution 3D T2* weighted, white matter attenuated (WHAT) turbo field echo and T1-weighted IR-TFE imaging. Cortical lesions were best seen with the WHAT sequence, and there was little reader variability. Olivier E. Mougin1, Jennifer Dixon1, Ian Donaldson2, Emma Tallantyre2, Nikos Evangelou2, Penny A. Gowland1 1Sir Peter Mansfield Magnetic Resonance Centre, School of Physics & Astronomy,University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Institute of Neuroscience, Nottingham, Nottinghamshire, United Kingdom This study aims to detect cortical lesions in MS patients. High resolution MTR scans (0.5mm isotropic, as well as 0.35mm in plane resolution) have been acquired at 7T using a novel imaging sequence. The MTR contrast has been compared between white matter and grey matter, showing a greater grey matter (GM) / white matter (WM) contrast to noise ratio at 7T, providing a good delineation of WM and GM lesions at high resolution with the MTR contrast. The sequence is being used to study changes in the cortex of MS patients. 2071. Surface-Based Analysis of Subpial T2*signal Changes at 7T in Multiple Sclerosis Julien Cohen-Adad1,2, Douglas Greve1,2, Thomas Benner1,2, Amy Radding1,2, R Philip Kinkel, 2,3, Bruce R. Rosen1,2, Bruce Fischl1,2, Caterina Mainero1,2 1A. A. Martinos Center for Biomedical Imaging, Dept. of Radiology, MGH, Charlestown, MA, United States; 2Harvard Medical School, Boston, MA, United States; 3Beth Israel Deaconess Medical Center, Boston, MA, United States The ability to detect and to classify in vivo gray matter (GM) lesions in multiple sclerosis (MS) is required to better understand pathological processes associated with disease progression and disability. In this paper we combined ultra high field MRI (7T) with surface-based analysis to achieve quantitative assessment of subtle and diffuse cortical changes in multiple sclerosis (MS). Results show a significant increase of the T2* signal in MS patients versus controls. This increase may reflect the diffuse subpial pathology that has been described in autopsy cases of MS. Surface-based analysis facilitates the characterization of cortical lesions in vivo. Alexandra Marion Seewann1,2, Hugo Vrenken3,4, Evert-Jan Kooi5, Paul van der Valk5, Dirk Knol6, Chris Polman1, Petra Pouwels4, Frederik Barkhof3, Jeroen Geurts, 3,5 1Neurology, VU University medical center, Amsterdam, Netherlands; 2Neurology, Medical University Graz, Graz, Austria; 3Radiology, VU University medical center, Amsterdam, Netherlands; 4Physics and Medical Technology, VU University medical center, Amsterdam, Netherlands; 5Pathology, VU University medical center, Amsterdam, Netherlands; 6Epidemiology and Biostatistics, VU University medical center, Amsterdam, Netherlands Only few lesions in cortical gray matter (CGM) of multiple sclerosis (MS) patients can be visualized with conventional MRI. Quantitative MRI techniques are more sensitive to cortical damage, but the histopathological correlates of quantitative MRI changes in the MS CGM are unclear. We aimed to define the underlying pathology of cortical quantitative MRI changes, and to compare MRI visible and invisible lesions by histopathology. 16 brain slices from 10 chronic MS patients were imaged with qualitative and quantitative MRI at 1.5T. Regions of interests were correlated with histopathology. Quantitative MRI measurements reflect the extent of cortical demyelination. Conspicuity of cortical GM lesions on conventional MRI is determined by lesional size.
Cherian Renil Zachariah1, David Pitt2, Peter Wassenar1, Bradley D. Clymer1, Amir Abduljalil1, Michael V. Knopp1, Petra Schmalbrock1 1Radiology, The Ohio State University, Columbus, OH, United States; 2Neurology, The Ohio State University, Columbus, OH, United States Depiction of cortical demyelination in MS is still hampered by low contrast, spatial resolution and specificity.This study applies T2*-gradient echo and inversion recovery turbo field echo (IR-TFE) sequences 7T to image formalin-fixed tissue specimen and measure T1,T2*,PD and phase differences. We notice that PD maps and phase maps may be promising for enhancing cortical lesion depiction . Following MRI, specimen were cut and labeled with anti-myelin basic protein antibodies to detect myelin and with anti-CD68 antibodies to detect activated macrophages/microglia. Scanned histology slides were scored for cortical lesions and compared to MRI 2074. MRI Texture Correlates of Pathological Findings in Post-Mortem Multiple Sclerosis Brain Yunyan Zhang1,2, GR Wayne Moore1, Cornelia Laule1, Thorarin A. Bjarnason2, Piotr Kozlowski1, Alex L. Mackay1, Anthony L. Traboulsee1, David K. B. Li1 1University of British Columbia, Vancouver, BC, Canada; 2University of Calgary, Calgary, AB, Canada Ten post-mortem brain samples from 3 MS subjects were imaged at 7T. Regions of interest were marked on histological sections staining for myelin and axon, then were matched on MR images including lesions (14), normal appearing white matter (NAWM, 12) and regions of reduced myelin and axon (rLrB). MRI texture analysis based on polar Stockwell Transform (PST) was performed. Texture was highest in lesions, intermediate in rLrB and lowest in NAWM (p < 0.01) providing evidence that texture abnormality associates with tissue pathology. PST analysis may be a potential tool to quantify tissue integrity in MS or other neurological disorders. 2075. Evaluating MACC for Improved MS Rater Agreement David S. Wack1, Michael G. Dwyer1, Niels Bergsland1, Sara Hussein1, Robert Zivadinov1 1University at Buffalo, Buffalo Neuroimaging Analysis Center, Buffalo, NY, United States The software method of Minimum Area Contour Change (MACC) is evaluated for use to improve same scan inter-rater agreement for the delineation of T2 hyper-intense MS lesions; and for the application of ROIs to follow up time points. The MACC method improves inter-rater agreement, and performs about on par with another rater for the purpose of drawing lesion ROIs on a follow-up scan. 2076. Lesion Recognition in Multiple Sclerosis: A Sequence Comparison and Quantification Study at 3T Tobias Kober1,2, Cristina Granziera3,4, Delphine Ribes1,2, Patrick Browaeys5, Myriam Schluep6, Katrin Wohlfarth7, Reto Meuli5, Gunnar Krueger2 1Laboratory for functional and metabolic imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 2Advanced Clinical Imaging Technology, Siemens Suisse SA - CIBM, Lausanne, Switzerland; 3Department of Neurology, Hōpitaux Universitaires de Genčve, Lausanne, Switzerland; 4Brain and Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 5Department of Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; 6Department of Neurology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; 7H IM MR PLM AW Neurology, Siemens AG, Erlangen, Germany Detection and radiological characterisation of multiple sclerosis (MS) lesions is an essential part both of clinical diagnosis and MS research. Ten early-stage MS patients and ten controls were included in this study aiming at (i) comparing five different high-resolution imaging sequences (FLAIR, MP-RAGE, DIR, SPACE, MP2RAGE) and (ii) quantifying T1 relaxation times of lesions with respect to their location in the brain. Results suggest that the DIR sequence is the most sensitive for total lesion count, followed by the MP2RAGE. Confirming previous studies, T1 relaxation times were found to be overall prolonged. 2077. Pre-Filling MS Lesions on T1 and T2-Weighted Images for Improved Tissue Segmentation Jonathan S. Jackson1,2, Declan Chard2, Antonia Ceccarelli1, Elisa Dell'Oglio1, Ashish Arora1, Mohit Neema1, Rohit Bakshi1, David Miller2, Claudia Angela Michela Wheeler-Kingshott2 1Laboratory for Neuroimaging Research, Brigham & Women's Hospital, Harvard Medical School, Brookline, MA, United States; 2Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom Robust lesion in-painting has been demonstrated on T1 and T2-weighted images. Many automated algorithms rely on accurate histograms for segmentation; therefore this approach to lesion WM correction based on the global histogram is appropriate and strongly recommended as a pre-processing step for MS images. Marios C. Yiannakas1, Daniel J. Tozer1, Declan T. Chard1, David H. Miller1, Claudia A.M Wheeler-Kingshott1 1UCL - Institute of Neurology, London, United Kingdom In this work a new MR analysis method is presented which utilises conventional FSE dual echo data sets with the use of advanced images algebra (ADIMA) in order to enhance the dynamic range in the image with a consequent enhancement of lesional heterogeneity in MS lesions. It is found that the images show bright and dark lesions indicating heterogeneity of pathological process. Masks of these bright and dark lesions are applied to MRI parameter maps and it is found that the corresponding areas on MTR, T1 and T2 maps show different values, corresponding to the two lesion types. Ryan Griffin1, Adam Brandenberry1, Jiachao Liang1, Christopher Murphy1, Trenton Rink1, Joe Konrad1, Xiangyu Yang1, Michael Knopp1, Steffen Sammet1 1Radiology, The Ohio State University, Columbus, OH, United States The purpose of this study was to use Dynamic Contrast Enhanced MRI at 3T to quantitatively study the perfusion of MS lesions. Using Brixs two compartment model, we found statistically significant differences in the mean extracted values of the pharmacokinetic values Amp and kel of enhancing lesions with respect to those from normal appearing brain tissue, as well as a statistically significant difference in the mean extracted value of Amp from hypointense lesions with respect to normal appearing brain tissue. Rising enhancement after the initial uptake of gadolinium (indicated by a negative kel value) was observed for every enhancing lesion. Wafaa Zaaraoui1, Franēoise Reuter1, Mathias Lemaire1, Audrey Rico1, Anthony Faivre1, Virginie Callot1, Irina Malikova1, Elisabeth Soulier1, Sylviane Confort-Gouny1, Patrick J. Cozzone1, Jean Pelletier1, Bertrand Audoin1, Jean-Philippe Ranjeva1 1Faculté de Médecine, CRMBM UMR CNRS 6612, Marseille, France Recent studies have evidenced the crucial role of perfusion alteration in multiple sclerosis (MS). However, little is known about the relationships between hemodynamical parameters and local tissue damage encountered at all stages of the disease, and especially at the early phase. To investigate the putative relationships between perfusion alterations and structural local white matter and grey matter impairments in early MS, we designed a MR protocol combining statistical mapping analyses of arterial spin labeling (ASL) data and magnetization transfer ratio (MTR) data obtained in 12 patients with clinically isolated syndromes (CIS) and 12 matched controls. 2081. Identifying the Start of Multiple Sclerosis Tissue Injury: A Longitudinal DTI Study Robert J. Fox1, Daniel Ontaneda1, Xiofeng Wang2, Ken Sakaie3, Jian Lin3, Mark J. Lowe3, Michael D. Phillips3 1Mellen Center for MS, Cleveland Clinic, Cleveland, OH, United States; 2Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, United States; 3Radiology, Cleveland Clinic, Cleveland, OH, United States We used HARDI DTI in a longitudinal study of multiple sclerosis patients to identify changes in brain tissue prior to the development of acute inflammation (gadolinium enhancement). We found significantly decreased fractional anisotropy (FA) up to 10 months prior to the development of gadolinium-enhancing lesions. Changes in FA were driven an increase in transverse diffusivity, while longitudinal diffusivity remained unchanged. This study provides evidence for impaired myelin integrity up to 10 months prior to development of gadolinium enhancement. Fuchun Lin1, Chunshui Yu2, Yaou Liu2, Hao Lei1 1Wuhan Institute of Physics & Mathematics, The Chinese Academy of Sciences, Wuhan, Hubei, China; 2Department of Radiology, Xuanwu Hospital of Capital Medical University, Beijing, China Diffusion tensor based group tractography was used to determine the corpus callosum (CC) integrity in clinically isolated syndrome (CIS). Compared to the healthy subjects, the CIS patients had significantly reduced midsagittal CC area, and significantly higher MD, λ 1, λ 23 and significantly lower FA in the entire CC. Moreover, the average FA of the normal-appearing CC of the CIS patients correlated negatively with the whole-brain lesion load while the other three diffusion indices correlated with the lesion load positively. These results suggested that both the morphology and the microstructure of the CC appear to be damaged at the stage of CIS. Salem Hannoun1,2, Franēoise Durand-Dubief, 1,3, Christian Confavreux3, Dominique Sappey-Marinier1,2 1CREATIS-LRMN, University of Lyon 1, Lyon, Rhone-Alpes, France; 2CERMEP-Imagerie du Vivant, Bron, Rhone-Alpes, France; 3Neurological Hospital, Lyon, Rhone-Alpes, France This study aims to characterize early pathological processes occurring in twelve multiple sclerosis (MS) patients with a clinically isolated syndrome (CIS) compared to relapsing remitting (RR) patients and control subjects using tract-based spatial statistics (TBSS). Significant alterations of diffusivity including FA decrease, and axial (ėa) and radial (ėr) diffusivities increases, were found in extensive white matter regions of CIS patients, with ėr being the most affected. If ėr alterations may reflect the demyelinating processes occurring in MS, ėa can be more evocative of late appearing axonal damage as confirmed by the increase of ėa in RR compared to CIS patients. 2084. Correlation of Clinical Parameters and DTI Imaging Features in Multiple Sclerosis Carli Jessica Lehr1, Mustafa Okan Irfanoglu1, Firdaus Janoos, Steffen Sammet1, Michael V. Knopp2 1Department of Radiology, The Ohio State University, Columbus, OH, United States; 2Department of Radiology, OSU, Columbus, OH, United States Diffusion Tensor Imaging plays an important role in the quantitative analysis of Multiple Sclerosis lesions. This study investigates the correlation between clinical parameters and DTI imaging features such as FA, ADC, lesion volumes, and tract connectivity. DTI derived features provide better correlations to clinical scores than conventional MRI-based characteristics. The strongest correlations were found when all DTI imaging features were analyzed together against clinical data values. This illustrates the usefulness of comprehensive DTI imaging features in analyzing clinical deficits in Multiple Sclerosis. Mustafa Okan Irfanoglu1, Raghu Machiraju1, Michael V. Knopp1, Steffen Sammet1 1Department of Radiology, The Ohio State University, Columbus, OH, United States Diffusion Tensor Imaging proved to be a useful modality for the diagnosis of Multiple Sclerosis. However, the quality of the DTI-derived scalar maps and tractography is directly dependent on experimental design. In clinical settings, scan time is a major constraint and not many diffusion weighted volumes can be acquired. In this work, we analyze the effects of gradient resolution on the appearance of multiple sclerosis regions. Results indicate that with increasing number of gradients, statistics based on lesion scalar map distributions becomes more stable and spending extra minutes might be beneficial if DTI is to be assessed for diagnosis. 2086. Radial Diffusivity in Remote Optic Neuritis Discriminates Visual Outcomes Junqian Xu1, Robert T. Naismith1, Nhial Tutlam1, Kathryn M. Trinkaus2, Sheng-Kwei Song3, Anne Cross1 1Neurology, Washington University in St. Louis, St. Louis, MO, United States; 2Biostatistics, Washington University in St. Louis, St. Louis, MO, United States; 3Radiology, Washington University in St. Louis, St. Louis, MO, United States We studied 70 remote optic neuritis (ON) patients using the previously described high-resolution reduced field-of-view optic nerve diffusion tensor imaging protocol at 3 T. Radial diffusivity (RD) strongly correlated with visual functional assessments, retinal nerve fiber layer thickness, and visual evoked potential. RD also discriminated nerves with normal recovery from those with mild visual impairment, and those with mild impairment from profound visual loss. In addition, RD differentiated healthy controls from both the clinically affected nerves and unaffected fellow nerves after ON. RD differentiated all categories of 5% contrast sensitivity (CS) outcomes, and all categories of Pelli-Robson CS with the exception of normal recovery from mildly affected. Robert A. Bermel1, Jeffrey A. Cohen1, Lael A. Stone1, Blessy Mathew2, Mark J. Lowe2, Michael D. Phillips2 1Neurological Institute, Cleveland Clinic, Cleveland, OH, United States; 2Imaging Institute, Cleveland Clinic, Cleveland, OH, United States Optic neuritis (ON) is caused by inflammatory demyelination in the optic nerve, commonly as an early component of multiple sclerosis (MS). Recovery from ON is variable, facilitated by mechanisms which may include remyelination and cortical reorganization. We used visual fMRI with stimuli at three different contrast levels to investigate cortical activation following ON in 6 patients with MS and remote unilateral ON. Differences in cortical activation between affected and unaffected eyes were most apparent when utilizing the lower contrast visual stimulus. We conclude that low-contrast visual fMRI may be sensitive to detect cortical changes following ON. Wolter L. de Graaf1, J. M. Hoogduin2, F. Visser2,3, P. Pouwels4, H. Vrenken4, C. H. Polman5, F. Barkhof1, P. R. Luijten2, J. A. Castelijns1 1Radiology, VU University Medical Center, Amsterdam, Netherlands; 2Image Science Institute, University Medical Center Utrecht, Utrecht, Netherlands; 3PHILIPS Healthcare; 4Physics and Medical Technology, VU University Medical Center, Amsterdam, Netherlands; 5Neurology, VU University Medical Center, Amsterdam, Netherlands In Multiple Sclerosis, T1 mapping has shown to be able to differentiate normal from normal appearing grey and white matter. At high field, T1 relaxation times increase and therefore it is expected that changes in brain tissue due to multiple sclerosis become more pronounced. A fast T1 mapping sequence of 4.5 minutes with an in-plane resolution of 1x1 mm2 and slice thickness of 1.5 mm is applied at 7 Tesla to assess the sensitivity of the method at high field. Patients as well as healthy controls are examined and whole brain histograms and analysis of specific brain regions are made. Jie Luo1, Pascal Sati2, Anne H. Cross3, Dmitriy A. Yablonskiy2 1Chemistriy, Washington University in St.Louis, St. Louis, MO, United States; 2Radiology, Washington University in St. Louis, St. Louis, MO, United States; 3Neurology, Washington University in St. Louis, St. Louis, MO, United States One reason for the weak correlation between conventional MRI (based on T1/T2 weighted images) and clinical findings is the inability of conventional MRI to quantify the extent of tissue damage. In this study, we demonstrated that an efficient method based on GEPCI technique not only depicts MS lesions similar to conventional T1w and FLAIR images, but also allows quantitative evaluation of disease progression. Combining characteristics of main peak in R2* histograms and quantitative score assigned to MS lesions, allows the evaluation not only of the volume of cerebral MS lesions, but incorporates the degree of tissue damage as well. 2090. Absolute Quantification of Myelin Related Volume in the Brain J. B.M. Warntjes1, J. West1,2, A. M. Landtblom1,3, P. Lundberg2 1Center for Medical Imaging Science and Visualization (CMIV), Linköping, Sweden; 2Department of Medicine and Health, Division of radiation physics, Linköping, Sweden; 3Department of Clinical Neuroscience, Linköping, Sweden A method is described to measure the myelin related volume fraction for each voxel for a complete brain within a scan time of 5 to 6 minutes, based on absolute quantification of the relaxation rates R1 and R2 and proton density. The absolute decrease of visible PD with a simultaneous increase of R1 and R2 corresponds to an increase of myelin. Myelin related volume is correlated with Fractional Anisotropy maps and conventional T1W, T2W and FLAIR images. Repeated measurements show a standard deviation of 1-2% in myelin volume for the whole brain. Irene Margaret Vavasour1, Shannon Heather Kolind2, Cornelia Laule1, Burkhard Maedler3, David K.B. Li1, Anthony L. Traboulsee4, Alex L. MacKay1,3 1Radiology, University of British Columbia, Vancouver, BC, Canada; 2FMRIB Centre, University of Oxford, Oxford, United Kingdom; 3Physics and Astronomy, University of British Columbia; 4Medicine, Univeristy of British Columbia Twelve multiple sclerosis subjects and 12 healthy age and gender matched controls were scanned twice at a 6 month interval to compare histograms derived from normal white matter (NWM), normal appearing white matter (NAWM) and multiple sclerosis lesions. Myelin water fraction (MWF), geometric mean T2 (GMT2), fractional anisotropy, mean diffusivity and the eigenvalues were measured. Mean MWF and GMT2 histograms did not differ between the two time points although histograms from NWM, NAWM and lesions were different. Histograms from the diffusion metrics differed slightly between month 0 and 6. T2 relaxation and diffusion metrics give complementary information about MS tissue. Cornelia Laule1,2, Shannon H. Kolind3, Irene M. Vavasour1, Burkhard Mädler2, Joel Oger4, Anthony L. Traboulsee4, Wayne Moore5, David KB Li1, Alex L. MacKay1 1Radiology, University of British Columbia, Vancouver, BC, Canada; 2Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada; 3FMRIB Centre, University of Oxford, Oxford, United Kingdom; 4Medicine, University of British Columbia, Vancouver, BC, Canada; 5Pathology & Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada Using T2 relaxation it is possible to measure myelin water fraction in multiple sclerosis (MS) normal appearing white matter (NAWM). Previous work employing a region of interest based approach found reduced myelin water fraction (MWF) in MS NAWM relative to normal white matter in controls. Using an improved 3D T2 relaxation sequence at higher field strength, we also found reduced MWF in MS NAWM which correlated with EDSS. Voxels with lowest MWF values were not uniformly distributed throughout the NAWM, but rather tended to arise near grey/white matter interfaces in the periphery of the brain. Lorena Jure1, Wafaa Zaaraoui1, Celia Rousseau1, Franēoise Reuter1, Audrey Rico1, Irina Malikova1, Sylviane Confort-Gouny1, Patrick J. Cozzone1, Jean Pelletier1, Bertrand Audoin1, Jean-Philippe Ranjeva1 1CRMBM UMR CNRS 6612, Marseille, France Various MR studies, based on group comparison have demonstrated a common pattern of grey matter (GM) injury in patients since the early stage of multiple sclerosis (MS). However, little is know about the potential variability of this early GM involvement which may determine the high variability of the functional prognosis. We propose an optimized method to obtain from statistical mapping analyses applied on MTR data, the GM MTR abnormalities of subjects at the individual level. Feasibility is demonstrated in early MS patients showing variable individual patterns of GM injury that could explain heterogeneity of clinical progression for this disease.
Maria A. Rocca1, Gianna Riccitelli1, Cristina Forn1, Bruno Colombo2, Giancarlo Comi2, Massimo Filippi1 1Neuroimaging Research Unit, Institute of Experimental Neurology, Division of Neuroscience, Scientific Institute and University Hospital San Raffaele, Milan, Italy; 2Department of Neurology, Scientific Institute and University Hospital San Raffaele, Milan, Italy Using voxel-based morphometry, we defined the topographical distribution of gray matter (GM) atrophy in multiple sclerosis (MS) patients with fatigue. Compared to healthy volunteers and to MS patients without fatigue, patients with fatigue had reduced GM volume in several areas of the left frontal lobe, including the middle frontal gyrus (MFG), the precentral gyrus, the superior and inferior frontal gyrus, and the cingulate gyrus. Fatigue severity was significantly correlated with atrophy of the precentral gyrus, suggesting that structural damage in areas that are part of the sensorimotor network might be among the mechanisms responsible for the presence of MS-related fatigue. Rose Gelineau-Kattner1,2, Tarunya Arun1, Damian Jenkins1, Morgan Hough1, Jacqueline Palace3, Mark Jenkinson1 1FMRIB Centre, University of Oxford, Oxford, United Kingdom; 2Baylor College of Medicine, Houston, TX, United States; 3Clinical Neurology, Oxford University and Oxford Radcliffe Hospitals NHS Trust, United Kingdom Grey matter damage is important in the pathology of Primary Progressive Multiple Sclerosis (PPMS). We scanned 22 patients and 7 controls at baseline, and 2, 50, and 52 weeks. FreeSurfer was used to segment subcortical grey matter and vertex analysis was performed with FSLs FIRST to identify differences in surface morphology between groups. Significant atrophy and correlations with EDSS and/or disease duration were seen in some structures at baseline and all structures showed volume reduction over one year. Surface morphology differences were found in the thalamus and pallidum. Results highlight importance of subcortical atrophy and structural morphology differences in PPMS. Kerstin Bendfeldt1, Louis Hofstetter, Pascal Kuster, Stefan Traud, Nicole Müller-Lenke, Yvonne Naegelin, Ludwig Kappos, Achim Gass, Thomas E. Nichols2, Frederik Barkhof3, Stephan Roosendaal3, Jeroen Geurts3, Hugo Vrenken3, Ernst-Wilhelm Radue, Stefan J. Borgwardt4 1University Hospital Basel, Basel, Basel-Stadt, Switzerland; 2University of Warwick; 3University of Amsterdam; 4Medical Image Analysis Centre, University Hospital Basel, Basel, Basel-Stadt, Switzerland We used optimized voxel-based morphometry to study similarities and differences of regional gray matter volume development in relapsing remitting and secondary progressive MS. Although regional gray matter volume measures reveal areas of significant gray matter volume loss in RRMS, the results from this study suggest, that there is no marked acceleration in the progressive phase of the disease. This implies that the more pronounced impact of gray matter pathology in the secondary progressive phase is a result of longer linear accrual of such damage, rather than a phase-specific acceleration. 2097. Gender Effects on Atrophy in MS: Cognitive Implications Menno M. Schoonheim1, Doriana Landi2, Jeroen JG Geurts1,3, Hugo Vrenken1,4, Ernesto J. Sanz-Arigita1, Linda Douw5, Chris H. Polman5, Frederik Barkhof1 1Radiology, VU University Medical Center, Amsterdam, Noord Holland, Netherlands; 2Universitą Campus Biomedico, Rome, Italy; 3Pathology, VU University Medical Center, Amsterdam, Noord Holland, Netherlands; 4Physics & Medical Technology, VU University Medical Center, Amsterdam, Noord Holland, Netherlands; 5Neurology, VU University Medical Center, Amsterdam, Noord Holland, Netherlands Multiple sclerosis displays clear gender effects in female predisposition, as well as male negative clinical prognosis. To investigate gender effects of atrophy and cognition in MS, we acquired brain volumes and neuropsychological assessments in 32 RRMS patients (14 male, 17 female) and 22 healthy controls (10 male, 12 female). Atrophy and cognitive impairment were present in male patients only. An interaction between group and gender was present for whole-brain volume and verbal memory. These were correlated in the patient group only. This underlines the need for future research to investigate gender effects in MS more thoroughly, with possible therapeutic implications. Katherine A. Koenig1, Blessy Mathew1, Jian Lin1, Lael Stone2, Stephen Rao3, Michael Phillips1, Mark J. Lowe1 1Imaging Institute, The Cleveland Clinic, Cleveland, OH, United States; 2Mellen Center, The Cleveland Clinic, Cleveland, OH, United States; 3Schey Center, The Cleveland Clinic, Cleveland, OH, United States Nineteen patients with MS performed a verbal incidental encoding task, followed by a word recognition task (WR). Stimuli from the WR task were split into encoded and non-encoded based on performance of each subject. The encoded stimuli of the five highest performers were used to create an average t-map to select regions of interest for a correlation analysis. Areas involved in semantic encoding, including the DLPFC and the inferior frontal gyrus, showed a significant positive correlation between the fit hemodynamic response amplitude during encoded stimuli on the WR task and a test of verbal memory. Benedetta Bodini1, Mara Cercignani2, Zhaleh Khaleeli1, Sophie Penny3,4, Maria Ron5, David H. Miller5, Alan J. Thompson1, Olga Ciccarelli1 1NMR Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom; 2Neuroimaging Laboratory, IRCCS Santa Lucia Foundation, Rome, Italy; 3NMR Unit, Department of Neuroinflammation, UCL Institute of Neurology , London, United Kingdom; 4Department of Psychology, National Hospital for Neurology and Neurosurgery, London, United Kingdom; 5NMR Unit, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom The aim of this study was to identify which brain area predicts the development of disability over five years and cognitive dysfunction after five years in 32 patients with early primary-progressive multiple sclerosis. Employing tract-based spatial statistics and voxel-based morphometry, we found that lower fractional anisotropy in the corpus callosum at study entry predicted a greater progression of disability, as measured by the EDSS, over the follow-up, and worse verbal memory, attention and speed of information processing, and executive functions, after five years. Our findings highlight the importance of damage to the inter-hemispheric callosal pathways in determining disability in MS. Wim Van Hecke1, Jan Sijbers2, Alexander Leemans3, Guy Nagels4, Evert Vandervliet1, Paul M. Parizel1 1Department of Radiology, Antwerp University Hospital, Antwerp, Belgium; 2VisionLab, University of Antwerp, Antwerp, Belgium; 3Image Sciences Institute, Utrecht, Netherlands; 4MS centrum, Melsbroek, Belgium The aim of this study was to examine the relationship between the Paced Auditory Serial Addition Test and the diffusion properties that are related to microstructural white matter breakdown in patients with mild and moderate Multiple Sclerosis. 2101. Early Compensatory Changes Within the Memory Network of Multiple Sclerosis Patients Hanneke E. Hulst1, Stefan D. Roosendaal1, Menno M. Schoonheim1, Lizanne J. Schweren1, Ysbrand D. van der Werf2, Chris H. Polman3, Frederik Barkhof1, Jeroen J. Geurts1,4 1Radiology, VU University Medical Center, Amsterdam, Noord-Holland, Netherlands; 2Clinical Neurophysiology, VU University Medical Center, Amsterdam, Noord-Holland, Netherlands; 3Neurology, VU University Medical Center, Amsterdam, Noord-Holland, Netherlands; 4Pathology, VU University Medical Center , Amsterdam, Noord-Holland, Netherlands Cognitive decline is frequently seen in multiple sclerosis (MS). This study investigates the changes in hippocampal activation patterns in MS. Functional MRI, an encoding- and retrieval paradigm, was acquired of 24 cognitively preserved (CP) and 10 cognitively impaired (CI) MS patients and 15 healthy controls (HC). Where CP patients only showed increased brain activation in the dorsal streams of the memory system, CI patients showed reduced brain activation in the (para)hippocampal areas and the ventral stream of the memory system. Our findings indicate that functional reorganization takes place early in the disease course and is a finite phenomenon in MS. Katherine A. Koenig1, Blessy Mathew1, Jian Lin1, Lael Stone2, Stephen Rao3, Michael Phillips1, Mark J. Lowe1 1Imaging Institute, The Cleveland Clinic, Cleveland, OH, United States; 2Mellen Center, The Cleveland Clinic, Cleveland, OH, United States; 3Schey Center, The Cleveland Clinic, Cleveland, OH, United States Eighteen patients with MS performed a verbal incidental encoding task, followed by a word recognition task. Performance on the WR task was used to split incidental encoding stimuli into encoded and non-encoded maps. The fit hemodynamic response amplitude during encoded and non-encoded stimuli on the encoding task was correlated with a test of verbal memory. Against expectation, the non-encoded words showed only positive correlations, while the encoded words showed only negative correlations with verbal memory performance. It is unclear if this result is due to disease processes in MS, or due to compensatory strategies. 2103. Cognitive Impairment in Early Multiple Sclerosis Related to Metabolic Impairment in Cerebellum Wafaa Zaaraoui1, Franēoise Reuter1, Audrey Rico1, Irina Malikova1, Elisabeth Soulier1, Patrick Viout1, Yann Le Fur1, Sylviane Confort-Gouny1, Patrick J. Cozzone1, Jean Pelletier1, Jean-Philippe Ranjeva1, Bertrand Audoin1 1Faculté de Médecine, CRMBM UMR CNRS 6612, Marseille, France While metabolic changes and cognitive impairment are known to be present in multiple sclerosis (MS) from the earliest stage of the disease, no exhaustive examinations have been performed to assess potential relationships between metabolite levels and cognitive status. Our study aimed to investigate whether magnetic resonance spectroscopic markers in normal appearing brain tissues are related to cognitive status in multiple sclerosis. Shannon Kolind1,2, Lucy Matthews1,3, Heidi Johansen-Berg1, Rose Gelineau-Kattner1,4, M Isabel Leite3, Jacqueline Palace3, Sean Deoni2 1FMRIB Centre, University of Oxford, Oxford, United Kingdom; 2Centre for Neuroimaging Sciences, King's College London, London, United Kingdom; 3Clinical Neurology, Oxford University and Oxford Radcliffe Hospitals NHS Trust, Oxford, United Kingdom; 4Baylor College of Medicine, Houston, TX, United States Critical need exists for a sensitive and specific biomarker in primary progressive multiple sclerosis (PPMS), which features diffuse neuronal and myelin damage. This study explored estimates of myelin water fraction (MWF) as such a biomarker. Sixteen PPMS patients were imaged using the mcDESPOT multi-component relaxometry technique, and correlations between MWF estimates and clinical disability scores were investigated. We found significant negative correlation between MWF and EDSS scores across diffuse brain regions. Correlations between MWF and specific scores of bladder/bowel, mental and sensory functions were found in appropriate brain regions. Findings support the emerging relevance of MWF changes to clinical manifestations. Cornelia Laule1,2, Irene M. Vavasour1, Burkhard Mädler2, Trudy Harris3, David KB Li1, Anthony L. Traboulsee4, Alex L. MacKay1,2 1Radiology, University of British Columbia, Vancouver, BC, Canada; 2Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada; 3UBC MRI Research Centre, University of British Columbia, Vancouver, BC, Canada; 4Medicine, University of British Columbia, Vancouver, BC, Canada Quantitative assessment of T1 and T2 relaxation has the potential to provide important in-vivo markers for disease progression and treatment efficacy in pharmaceutical trials. The present study examine cross-site reproducibility of mean T1, geometric mean T2 (GMT2) and myelin water fraction (MWF) measured on the same 5 people at 6 sites. Average percent differences of inter and intra-site reproducibility was <1% for GMT2, ~3% for T1 and ~6% for MWF. While mean T1 and GMT2 have slightly better reproducibility, MWF provides a specific measure of brain myelin content, and is hence ideal for assessing neuroprotective and remyelination strategies. Madeleine Hodgson1, Cornelia Laule1,2, Irene Vavasour1,2, Burkhard Mädler1, Alex MacKay1,2 1Physics, University of British Columbia, Vancouver, British Columbia, Canada; 2Radiology, University of British Columbia, Vancouver, British Columbia, Canada Little is known about the pathological evolution of acute MS lesions. Using 1H-MRS one can measure changes in metabolites such as n-acetyl-aspartate (NAA), which may become altered in MS. We used 1H-MRS and water proton T1 measurements to investigate the time-course of biochemical changes occurring in new MS lesions. Multi-voxel 1H-MRS data was acquired monthly from 20 Relapsing-Remitting MS subjects. Metabolite and water proton T1 changes for the same volume were investigated Lesions exhibited a significant decrease in NAA and a significant increase in mean T1, compared to normal appearing white matter, 2 months before lesion appearance on conventional imaging. Madeleine Hodgson1, Cornelia Laule1,2, Irene Vavasour1,2, David Li2, Yinshan Zhao3, Tony Traboulsee3, Joel Oger3, Alex MacKay1,2 1Physics, University of British Columbia, Vancouver, British Columbia, Canada; 2Radiology, University of British Columbia, Vancouver, British Columbia, Canada; 3Medicine, University of British Columbia, Vancouver, British Columbia, Canada 1H-MRS is a useful technique for evaluating demyelination and axonal integrity and thus can be used to monitor disease progression in Multiple Sclerosis (MS). Dirucotide (MBP8298) has exhibited potential as a treatment for Secondary Progressive MS (SPMS) to slow disease progression. The effects of Dirucotide were investigated using 1H-MRS in a single centre, double-blinded MRI substudy with a placebo control. There is no change observed in important metabolites in either of the cohorts over a two-year period, which is perhaps not surprising given that Dirucotide did not meet primary endpoints in the MAESTRO-01 Phase III trial. In-Young Choi1,2, Sang-Pil Lee1,3, Sharon G. Lynch4 1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States; 2Department of Neurology, Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, United States; 3Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, United States; 4Department of Neurology, University of Kansas Medical Center, Kansas City, KS, United States Oxidative stress has been implicated in multiple sclerosis (MS), a chronic inflammatory disease with the presence of a neurodegenerative process particularly in progressive MS. However, the effects of oxidative stress in MS have not been well described in the living human brain. In this study, we measured the cerebral GSH levels in the patients with secondary progressive MS (SPMS) using doubly selective multiple quantum GSH CSI. The GSH levels were significantly lower in the SPMS patients compared with those in the age- and gender-matched healthy controls, indicating the presence of increased oxidative stress in the absence of measurable inflammation. Guy U. Poloni1, Paolo Zamboni2, E. Mark Haacke3, Stefano Bastianello4, Michael G. Dwyer1, Niels Bergsland5, Claudiu V. Schirda1, David Wack1, Christopher R. Magnano1, Bianca Weinstock-Guttman6, Fabrizio Salvi2, David Hojnacki6, Robert Zivadinov1 1University at Buffalo, Buffalo Neuroimaging Analysis Center, Buffalo, NY, United States; 2University of Ferrera- Bellaria Neurosciences, Vascular Diseases Center, Ferrera, Italy; 3Radiology, Wayne State University, Detroit, MI, United States; 4Institu Neurologico Casimiro Mondino, Neuroradiology Unit, Pavia, Italy; 5University at Buffalo, Buffalo Neuroimaging Analysis Center, Buffalo, United States; 6University at Buffalo, The Jacobs Neurological Institute, Buffalo, NY, United States To develop an objective method for quantifying venous vasculature in brain parenchyma on susceptibility-weighted imaging (SWI). To apply this technique in multiple sclerosis (MS) patients and in healthy controls (HC). Michael G. Dwyer1, Niels Bergsland2, Claudiu Schirda2, Mari Heininen-Brown, Ellen Carl, David Wack, Guy U. Poloni, Robert Zivadinov3 1Buffalo Neuroimaging Analysis Center; 2University at Buffalo, Buffalo Neuroimaging Analysis Center, Buffalo, NY, United States; 3Neurology, Buffalo Neuroimaging Analysis Center, Buffalo , NY , United States Susceptibility-weighted imaging (SWI) has gained much interest recently as a sensitive means for detecting iron deposition in a variety of diseases, including multiple sclerosis (SM). We propose a fast and reproducible analysis pipeline to extract detailed quantitative SWI data and to combine it with other established indicators of disease state (including magnetization transfer and perfusion imaging). Robert Zivadinov1, Paolo Zamboni2, E. Mark Haacke3, Erica Menegatti4, Bianca Weinstock-Guttman5, Claudiu Schirda1, Anna M. Malagoni2, David Hojnacki5, Cheryl Kennedy1, Ellen Carl1, Niels Bergsland1, Sara Hussein1, Mari Heininen-Brown1, Ilaria Bartolomei6, Fabrizio Salvi2, Michael G. Dwyer1 1University at Buffalo, Buffalo Neuroimaging Analysis Center, Buffalo, NY, United States; 2University of Ferrera- Bellaria Neurosciences, Vascular Diseases Center, Ferrera, Italy; 3MR Research Facility, Wayne State University, Detroit, MI, United States; 4University of Ferrera- Bellaria Neurosciences, Vascular Diseases Center, Buffalo, NY, United States; 5University at Buffalo, The Jacobs Neurological Institute, Buffalo, NY, United States; 6University of Ferrera- Bellaria Neurosciences, Vascular Diseases Center, Ferrera, NY, United States Chronic cerebrospinal venous insufficiency (CCSVI) is a vascular picture in multiple sclerosis patients characterized by stenoses affecting the main extracranial venous outflow pathways and by a high rate of cerebral venous reflux that may lead to increased iron deposition in the brain. We explored relationship between venous hemodynamic (VH) parameters and disability and iron concentration in deep-gray matter (DGM) structures and lesions on susceptibility-weighted imaging. There was a significant association between higher number of VH criteria and higher iron concentration in T2 and T1 lesion volumes. Higher iron concentration in DGM structures was strongly associated with higher disability status. 2112. Cine Cerebrospinal Fluid Imaging in Multiple Sclerosis. a Case-Control Study Robert Zivadinov1, Christopher Magnano2, Bianca Weinstock-Guttman3, David Wack2, Eric Lindzen3, David Hojnacki3, Niels Bergsland2, Cheryl Kennedy2, Justine Reuther2, Michael G. Dwyer2, Claudiu Schirda2 1Neurology, Buffalo Neuroimaging Analysis Center, Buffalo , NY , United States; 2University at Buffalo, Buffalo Neuroimaging Analysis Center, Buffalo, NY, United States; 3University at Buffalo, The Jacobs Neurological Institute, Buffalo, NY, United States To investigate the cerebrospinal fluid (CSF) dynamics in Sylvius aqueduct in multiple sclerosis (MS) patients versus healthy controls (HC) and to define correlates with other specific disease metrics.
Claudiu Schirda1, Paolo Zamboni2, Christopher Magnano1, Eric Lindzen3, David Wack1, Bianca Weinstock-Guttman3, Deepa Ramasamy1, Ellen Carl1, David Hojnacki3, Cheryl Kennedy1, Michael Dwyer1, Niels Bergsland1, Jennifer Cox1, Fabrizio Salvi2, Robert Zivadinov1,3 1Buffalo Neuroimaging Analysis Center, University at Buffalo, Buffalo, NY, United States; 2University of Ferrara, Ferrara, Italy; 3The Jacobs Neurological Institute, University at Buffalo, Buffalo, NY, United States When compared to white matter or gray matter, the involvement of the cerebrospinal fluid (CSF) in the Multiple Sclerosis (MS) disease has scarcely been explored until now and typically a lumbar puncture is required. We investigate the flow properties of the CSF in the aqueduct of Sylvius and how they relate to other MS disease metrics, by using non-invasive MRI in a pilot study with MS patients and healthy controls. An objective flow quantification technique using automatic segmentation of the aqueduct was developed and was validated on a flow phantom and scan-rescanning 4 subjects within a week. Ileana Ozana Jelescu1, Ilana Ruth Leppert1, Sridar Narayanan1, Douglas L. Arnold1, G Bruce Pike1 1Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada Accurate and reproducible measurements of blood-brain barrier permeability in MS enhancing lesions would benefit follow-ups of lesion activity and comparison of detection sensitivity between different Gd-enhanced protocols. We propose a Dynamic Contrast Enhanced MRI protocol that allows sampling of the arterial input function with high temporal resolution in the first minute post-injection, followed by a lower temporal resolution but high spatial resolution acquisition of enhancement in lesions. This dual temporal resolution method was tested experimentally and through simulations and, compared to previous methods, has proven to yield more accurate and precise estimates over a wide range of permeability values. Andrea Kassner1,2, Igor Sitartchouk1, Rebecca E. Thornhill1,2, Timothy J. Carroll3, Chaitali Mulay4, Richard Aviv1,4 1Medical Imaging, University of Toronto, Toronto, Ontario, Canada; 2Physiology and Experimental Medicine, Hospital for Sick Children, Toronto, Ontario, Canada; 3Radiology, Northwestern University, Chicago, IL, United States; 4Neuroradiology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system. While blood-brain barrier (BBB) disruption associated with relapsing-remitting MS is readily identified using gadolinium-enhanced T1-weighted MRI, these MRI markers lack the sensitivity required for monitoring secondary progressive MS. Relative recirculation (rR), a parameter extracted from dynamic susceptibility contrast (DSC) data, can delineate BBB disruption in patients with acute ischemic stroke. Relative recirculation was measured from DSC perfusion data obtained from 19 patients with secondary progressive MS. The average lesion rR was significantly greater than in normal appearing white matter and shows potential for monitoring secondary progressive MS. Guy U. Poloni1,2, Michael G. Dwyer1, Niels Bergsland1, Claudiu V. Schirda1, Stefano Bastianello2, Robert Zivadinov3,4 1Buffalo Neuroimaging Analysis Center, Buffalo, NY, United States; 2Neuroradiology Unit, Fondazione Istituto Neurologico Casimiro Mondino IRCCS, Pavia, Italy; 3Buffalo Neuroimaging Analysis Center, Buffalo , NY , United States; 4The Jacobs Neurological Institute, University at Buffalo, Buffalo, NY, United States SWI is a MRI application that can directly image cerebral veins through the use of phase information to enhance local susceptibility. The present work introduces an algorithm, based on a 3-dimensional linear filter, for segmenting and measuring vein vessels in the brain and for classifying vessels according to their diameter. The resultant multi-scale line-filtered images provide significantly improved segmentation and visualization of curvilinear structures, in particular with respect to small vessels, contributing to the quantitative investigation of vascular impairment in the pathologies of the central nervous system. White Matter Diseases Hall B Tuesday 13:30-15:30 Christopher James Andrew Cowie1,2, Benjamin S. Aribisala1, Jiabao He1, Joshua Wood1, Alexander David Mendelow2, Patrick Mitchell2, Andrew M. Blamire1 1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne & Wear, United Kingdom; 2Department of Neurosurgery, Newcastle General Hospital, Newcastle upon Tyne, Tyne & Wear, United Kingdom Mild traumatic brain injury (mTBI) is associated with long term cognitive and affective symptoms. Findings on conventional MRI often do not account for the duration and severity of these symptoms. The aim of this study was to ascertain whether MR relaxometry and diffusion tensor imaging would reveal abnormalities in normal appearing white matter (NAWM) in patients with mTBI. Whole group analysis showed no significant differences, but after grouping the patients according to the side of the visible lesion, a significant increase in the mean diffusivity (MD) of ipsilateral frontal lobe NAWM was demonstrated. Manoj Kumar1, Deepa Pal1, Ram KS Rathore2, Bal K. Ojha3, Anil Chandra3, Raj Kumar3, Rakesh Kumar Gupta1 1Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 2Mathematics and Statistics, Indian Institute of Technology, , Kanpur, Uttar Pradesh, India; 3Neurosurgery, Chhatrapati Shahuji Maharaj Medical University,, Lucknow, Uttar Pradesh, India Diffusion tensor imaging (DTI) was performed within 7 days and after 6 months of injury in 21 traumatic brain injury (TBI) patients with frontal lobe injury and 21 age/sex matched controls. Diffusion tensor tractography (DTT) was proposed for quantification of various white matter (WM) tracts in patients with frontal lobe injury to assess diffuse axonal injury (DAI) and to look for correlation of these fiber bundles measures with various neuropsychological tests (NPT). We found reduced fractional anisotropy (FA) and increased mean diffusivity (MD) values in all WM tracts in TBI patients compared to controls, NPT scores were found to be significantly impaired in follow-up patients compare to controls and some of these tests showed significant correlation with DTI indices with different WM tracts. WM tracts which show significant difference on DTT were also correlated with those NPT which are associated with main function of frontal lobe such as memory, attention, visual and motor function. It appears more realistic methods for DAI quantification in TBI patients and provides information about structural integrity and connectivity of whole fiber tracts. Wang Zhan1, Grant Gauger2, Lauren Boreta1, Gary Abrams2, Karl Young1, Yu Zhang1, Marzieh Nezamzadeh1, Norbert Schuff1, Michael W. Weiner1 1Radiology and Medical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2VA Medical Center, San Francisco Fornix is one of the primary white matter structures of the limbic system, and its damage in mild traumatic brain injury (TBI) may explain the memory and learning dysfunctions in the post-concussion syndrome. N=24 TBI patients were longitudinally studied in two time points using T1 anatomical imaging and diffusion tensor imaging (DTI) to measure the fornix-to-brain ratio (FBR) and WM integrity of fornix, and compared with matched healthy controls. Our data show that the WM degradation in fornix onset in the acute stage after mild TBI, and that this degradation continued during the following 6-month period of recovery. Benjamin Segun Aribisala1, Christopher J.A. Cowie1,2, Jiabao He1, Joshua Wood1, David A. Mendelow2, Patrick Mitchell2, Andrew M. Blamire1 1Institute of Cellular Medicine, Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, England, United Kingdom; 2Department of Neurosurgery, Newcastle General Hospital, Newcastle University, Newcastle upon Tyne, England, United Kingdom Traumatic head injury is one of the major causes of neurological morbidity and mortality in the UK with more than 0.1 million admissions per year with primary diagnosis of head injury. This constitutes a huge drain on medical resources. Majority of these patients have ongoing symptoms which do not correlate with MRI or CT findings. Here we investigated a cohort of patients with mild TBI using multi-parametric real space analysis. Our results show that a fully automatic real space method of analysing quantitative MR parameters can be used to detect changes in normal appearing tissues in patients suffering mild TBI. Steve Sawiak1, Virginia FJ Newcombe2, M G. Abate2, Jo G. Outtrim2, John D. Pickard1, T A. Carpenter1, Guy B. Williams1, David K. Menon2 1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom; 2Division of Anaesthesia, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom Atrophy is common post traumatic brain injury (TBI) and may correlate with outcome. We hypothesised that quantification of Jacobian determinants could assess progressive changes in brain volume in within subject analyses, even in contexts that produce major problems with comparative analyses. We show implementation of the approach in a single TBI subject with serial scans before and up to 12 months after decompressive craniectomy, compared to results from healthy controls. The results indicate it is possible to monitor the changes in brain volume over time post TBI in an individual. H Huang1,2, M Deng1, S F. Leung3, Y L. Chan1, D K. Yeung1, H C. Chan1, A T. Ahuja1, Y X. Wang1 1Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong; 2Department of Radiology, The Shenzhen Third Peoples Hospital, Shenzhen, China; 3Department of Clinical Oncology, The Chinese University of Hong Kong, Prince of Wales Hospital The natural course of radiation induced brain injury still remains poorly understood. Among the abnormalities white matter edema-like lesions (WML) and contrast enhanced necrotic lesions (CEL) have been most commonly reported. It was recently reported that radiation induced brain injury was not always an irreversible and progressive process, but one that could show regression and resolution. In total 22 nasopharyngeal carcinoma patients with 36 lobes displaying WML and CEL were analysed in this study. The preliminary results of this study suggest the development of WML and CEL tend to follow the same pattern, and not develop in the opposite direction. Otto Rapalino1, Mara Kunst1, Patricia Musolino2, Florian Eichler2,3 1Radiology, Massachusetts General Hospital, Boston, MA, United States; 2Neurology, Massachusetts General Hospital, Boston, MA, United States; 3Martinos Center for Biomedical Imaging, Charlestown, MA, United States Dynamic Susceptibility Contrast (DSC) MR perfusion was used to characterize the perfusion abnormalities in patients with adrenoleukodystrophy and adrenomyeloneuropathy. This study demonstrates that the combination of conventional MR and DSC perfusion MR techniques allows the definition of five different zones with characteristic profiles of abnormal signal and perfusion in patients with adrenoleukodystrophy that correspond to the zonal anatomy previously described on pathological studies. These findings can be helpful in predicting disease progression, selecting patients for therapeutic interventions and elucidating the pathophysiology of this disorder. Aliya Gifford1, Anna Binstock2, Joseph Wang3, Kathy Zackowski3,4, Jonathan Farrell5,6, Peter C.M. van Zijl5,6, Gerald Raymond1,4, Seth Smith7,8 1Department of Neurogenetics, Kennedy Krieger Institute, Baltimore, MD, United States; 2University of Maryland School of Medicine, Baltimore, MD; 3Motion Analysis Laboratory, Kennedy Krieger Institute, Baltimore, MD; 4Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD; 5Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD; 6F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD; 7Vanderbilt University Institute of Imaging Science, United States; 8Department of Radiology, Vanderbilt University, Nashville, TN Adrenomyeloneuropathy (AMN) is characterized by primary distal axonopathy with secondary demyelination. In this study we performed diffusion tensor imaging (DTI) at 1.5T on 29 healthy volunteers and 39 AMN patients. Tractography of the left and right corticospinal tracts (CST) were performed and diffusion anisotropy and diffusivity were computed. A significant change in FA and perpendicular diffusivity was found from the pons to mid-brain (p<0.01) and mid-brain to thalamus (p<0.001) regions in AMN patients. This suggests that DTI can quantify the pathway-specific abnormalities in AMN, and results are in corroboration with knowledge that cerebral damage is present in AMN. Xiao-Qi Ding1, Annette Bley2, Alfried Kohlschütter2, Jens Fiehler3, Heinrich Lanfermann1 1Institute of Diagnostic and Interventional Neuroradiology , Hannover Medical School, Hannover, Germany; 2Department of Paediatrics, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany; 3Department of Neuroradiology, University Medical Centre Hamburg-Eppend, Hamburg, Germany Bone marrow transplantation (BMT) has been advocated as treatment of juvenile metachromatic leukodystrophy (MLD). The effectiveness of this high-risk treatment is still questionable due to the rarity of follow-up reports. We carried out a 7 years MRI follow-up on a boy with juvenile MLD who had received BMT treatment in the presymptomatic phase and remained free of MLD symptoms during the observation. Conventional morphological MRI showed minor stable white matter lesions while quantitative T2-mapping and MR spectroscopy evidenced a stagnancy of the demyelination process and an ongoing maturation of the brain. Onur Ozyurt1, Alp Dincer2, Zuhal Yapici3, Cengiz Yalcinkaya4, Mefkure Eraksoy3, Cengizhan Ozturk1 1Bogazici University, Biomedical Engineering Institute, Istanbul, Turkey; 2Acibadem University, School of Medicine, Department of Radiology; 3Istanbul University, Istanbul Faculty of Medicine, Department of Neurology; 4Istanbul University, Cerrahpasa Medical Faculty, Department of Neurology In this study, tract based spatial statistics (TBSS) approach is used for the investigation of Pelizeaus-Merzbacher Disease (PMD), which is a rare X-linked disease characterized by defective central nervous system myelination due to a mutation in the proteolipid protein 1 gene.
2127. In Vivo Proton MR Spectroscopy Findings Specific for Adenylosuccinate Lyase Deficiency Steffi Dreha-Kulaczewski1, Marco Henneke1, Knut Brockmann1, Marinette van der Graaf2,3, Michel Willemsen4, Udo Engelke5, Peter Dechent6, Arend Heerschap3, Gunther Helms6, Ron Wevers5, Jutta Gaertner1 1Department of Pediatrics and Pediatric Neurology, Georg August University, Goettingen, Germany; 2Clinical Physics Laboratory in the Department of Pediatrics, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands; 3Department of Radiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands; 4Department of Pediatric Neurology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands; 5Laboratory of Genetic, Endocrine and Metabolic Diseases, Department of Laboratory Medicine, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands; 6MR-Research in Neurology and Psychiatry, Georg August University, Goettingen, Germany Adenylosuccinate lyase (ADSL) deficiency is an inherited metabolic disorder and characterized by the accumulation of succinylaminoimidazolecarboxamide riboside and succinyladenosine (S-Ado) in tissue and body fluids. In three children, presenting with psychomotor delay, autistic features, and white matter changes on brain MRI, screening for inborn errors of metabolism included in vitro proton MRS. It revealed resonances at 8.27 and 8.29ppm that correspond to S-Ado. In vivo proton MRS showed a signal at 8.3ppm in gray and white matter brain regions of all three patients, which was undetectable in controls. In vivo proton MRS provides a conclusive finding in ADSL deficiency. Marinette van der Graaf1,2, Udo F.H. Engelke3, Eva Morava4, Mirian C.H. Janssen5, Maaike C. de Vries4, Leo AJ Kluijtmans3, Bozena Goraj1, Arend Heerschap1, Ron A. Wevers3 1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 2Clinical Physics Laboratory, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 3Laboratory of Genetic, Endocrine and Metabolic Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 4Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 5General Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands Recently, our group showed for the first time cerebral accumulation of 3-hydroxyisovaleric acid (3HIVA) in a pediatric patient with 3-Methylcrotonyl-CoA Carboxylase deficiency (MCCD). 3HIVA has been considered to have neurotoxic effects, but this is under debate. The present study reports on cerebral accumulation of 3HIVA detected by 3T proton MRS in two adult women with MCCD, whom deficiency was discovered by a positive neonatal screening of their healthy new-born babies. As the women had not been aware of having this disorder before and they have no or limited complaints, 3HIVA is postulated to have no or minor neurotoxic effect. 2129. White Matter Lesion Load in Type 2 Diabetes - A VBM Study Lars Eric Forsberg1,2, Sigurdur Sigurdsson3, Thor Aspelund3,4, Jesper Fredriksson2, Smįri Kristinsson2, Ólafur Kjartansson3, Bryndķs Óskarsdóttir3, Pįlmi V. Jónsson3,4, Gudnż Eirķksdóttir3, Tamara B. Harris5, Mark A. van Buchem6, Alex Zijdenbos7, Lenore J. Launer5, Vilmundur Gudnason3,4 1Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden; 2Raförninn ehf, Reykjavik, Iceland; 3Icelandic Heart Association, Kopavogur, Iceland; 4The University of Iceland, Reykjavik, Iceland; 5Laboratory of Epidemiology, Demography, and Biometry, National Institute of Aging, Bethesda, MD, United States; 6Department of Radiology, Leiden University Medical Center, Leiden, Netherlands; 7Biospective Inc., Montreal, Canada Type 2 diabetes (DM2) is a known risk factor for white matter lesions (WML) in elderly subjects. In this study, we used voxel-based morphometry (VBM) to analyse the common distribution of WML in 215 subjects with DM2 (average age 76.1 years) compared to 1675 non-diabetic controls (average age 75.8 years). Our main finding is that DM2 subjects have commonly large WML areas in the brain that extend from the frontal lobe to the parietal lobe. Peng Zhao1, Vera Novak1, Kun Hu1, Medha Munshi1, David Alsop2, Amir Abduljalil3, Peter Novak4 1Gerontology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 2Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 3Radiology, Ohio State University, Columbus, OH, United States; 4Neurolgoy, University of Massachusetts Medical School, Worcester, MA, United States Type 2 DM is a major risk factor for both large and small vessel atherosclerosis, stroke, and vascular dementia. Hyperglycemia is a common mechanism of endothelial dysfunction and neuronal cell damage. Microvascular disease manifests as white matter hyperintesities on MRI, regional atrophy and functional decline. Inflammation further affects microcirculatory regulation and contributes to arteriolosclerosis. We investigated the effects of inflammation on regional perfusion and neurodegenerative changes in grey and white matter on MRI. Inflammatory markers had different effects on regional brain volumes. sICAM was associated with atrophy across all regions in the DM group, with the most significant effects in the frontal and parietal regions. In the control group, regional perfusion on both sides in the parietal lobe is positively correlated with sICAM, and perfusion in the right occipital lobe is positive with sVCAM. Associations between regional brain volumes and other inflammatory markers were not prominent. Frontal and parietal regions with high energy demands are more vulnerable to the effects of DM in the brain. 2131. Quantification of Frontal Glutamate Neurotranmission in Human HIV Napapon Sailasuta1, Kimbery Shriner2, Kent Harris1, Thao T. Tran1,3, Osama Abulseoud4, Brian D. Ross1,5 1Clinical MR Spectroscopy, Huntington Medical Research Institutes, Pasadena, CA, United States; 2The Phil Simon Clinic, Huntington Memorial Hospital, Pasadena, CA, United States; 3Rudi Schulte Research Institute, Santa Barbara, CA, United States; 4University of Southern California, Keck School of Medicine, Los Angeles, CA, United States; 5Rudi Schulte Research Institute, Santa Barbara , CA, United States Despite successful treatment of HIV and AIDS, neuroimaging and neurospectroscopy abnormalities persist suggesting residual viral effects or unwanted neurological side effects of effective therapies. Elucidation of the recently described reduction in frontal lobe glutamate concentration in white matter of HIV-affected individuals requires independent 13C MRS measurement of glutamate turnover neurotransmitter rates in neurons and glia. This study develops the necessary frontal lobe assay of neuronal and axonal glutamate turnover by infusion of 2-13C glucose followed by low-power nOe 13C MRS in HIV and normal control subjects. Preliminary results indicate reduced 13C glutamate turnover in successfully treated HIV. 2132. Proton MR Spectroscopy Findings in Chronic Neuroborreliosis Caitlin Judith Hardy1, Amit Gokhale2, David Younger2, Nissa Perry2, Oded Gonen2 1Radiology, NYU, New York, NY, United States; 2NYU School of Medicine Abnormal metabolite levels were found in 3/3 patients with a diagnosis a post Lyme disease syndrome using 1H-MRS. Animal Models of White Matter Disease Hall B Wednesday 13:30-15:30 2133. Vascular Endothelial Growth Factor - A Novel Player in SCI Pain Laura Sundberg1, Juan Herrera1, Olivera Nesic2, Ponnada Narayana1 1Diagnostic and Interventional Imaging, The University of Texas Medical School, Houston, TX, United States; 2Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, United States Vascular endothelial growth factor (VEGF) has been investigated as a potential treatment for spinal cord injury (SCI) due to its vascular-promoting and neuroprotective effects; however, studies have provided conflicting information about the post-SCI effects of VEGF. In this study, VEGF was delivered immediately after SCI and longitudinal MRI and behavioral studies were performed into the chronic phase of injury. It was found that VEGF treatment results in tissue sparing and increased markers of neurofilament, but many animals also displayed a higher incidence of mechanical allodynia. VEGF may spare tissue, but may also encourage non-specific sprouting of axons into pain pathways. Katharina Schregel1, Eva Wuerfel1, Jens Wuerfel1, Dirk Petersen1, Ralph Sinkus2 1University of Luebeck, Luebeck, Germany; 2Institut Langevin, ESPCI, Paris, France MRE is an innovative imaging technique developed to non-invasively map and quantify the viscoelastic properties of tissue in vivo. As pathological alterations cause changes in elasticity and viscosity, MRE might be applied to characterize the structural integrity of given tissues and could be employed for diagnosis and clinical monitoring of neurodegenerative diseases such as multiple sclerosis. Therefore it appears to be essential to evaluate the effect of pathological processes occurring in multiple sclerosis on the viscoelastic properties of cerebral tissue with the help of experimental rodent models. We introduced the cuprizone mouse-model (C57/black6) which depicts key features of multiple sclerosis. 2135. Hybrid Diffusion Imaging in a Spinal Cord Model of Dysmyelination A P. Hosseinbor1, I D. Duncan2, A L. Alexander, A A. Samsonov3, Y-C Wu4, S A. Hurley, R A. Fisher, A S. Field3 1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Medical Sciences, University of Wisconsin-Madison; 3Radiology, University of Wisconsin-Madison; 4Dartmouth College The shaking pup (shp) is a canine mutant model of dysmyelination, and suffers from severe myelin deficiency. In a previous study of shp brain, Po was shown to differentiate between a control and diseased pup with respect to myelin content. In this study, WM integrity is examined in the spinal cord of shp using both DTI and DSI measurements acquired from a HYDI approach. Standard DTI measures and Po are compared to see if one or both are sensitive to changes in myelin content between shp and control, as well as to more subtle differences between two diseased pups. Erwin Lambert Blezer1, Yolanda S. Kap2, Jan Bauer3, Bert L. 't Hart2 1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 2Department of Immunobiology, Biomedical Primate Research Center, Rijswijk, Netherlands; 3Brain Research Institute, University of Vienna, Vienna, Austria Cortical pathology is an important feature of MS. However visualization with MRI is poor although sensitivity is increased using FLAIR and Double Inversion Recovery (suppression of CSF and white matter) experiments. Various inversion recovery experiments were tested ex vivo on brains of marmoset with MS, which develop cortical lesions, in their ability to improve cortical lesion detection. Experiments included settings of inversion times in which CSF, white or grey matter was suppressed and a DIR experiment in which both white and grey matter was suppressed. Cortical lesions were best visualized after suppression of white matter or in the DIR experiment. 2137. Increasing Diffusion Time Improves in Vivo DTI Sensitivity to White Matter Degeneration Ying-Jr Chen1, Joong Hee Kim1, Jian Wang1, Tsang-Wei Tu, 12, Sheng-Kwei Song1 1Radiology, Washington University in St. Louis, Saint Louis, MO, United States; 2Mechanical, Aerospace and Structural Engineering, Washington University in St. Louis, Saint Louis, MO, United States The sensitivities of detecting white matter injury using 6 ms and 38 ms diffusion time were examined in the present study. We demonstrated that increased diffusion time in diffusion tensor imaging measurements improves the sensitivity of detecting axonal injury and myelin damage in cuprizone treated mice. In the cuprizone model of demyelination, axonal injury was seen as significantly decreased axial diffusivity at both 6 and 38 ms diffusion time with more significantly decreased axial diffusivity observed at longer diffusion time. Gregory Harrison Turner1, Junwei Hao2, Ruolan Liu2, Wenhua Piao2, Timothy L. Vollmer3, Rong Xiang4, Antonio La Cava5, Denise I. Campagnolo2, Luc Van Kaer6, Fu-Dong Shi2 1Keller Center for Imaging Innovation, Barrow Neurological Institute, Phoenix, AZ, United States; 2Neurology, Barrow Neurological Institute, Phoenix, AZ, United States; 3Neurology, University of Colorado Denver School of Medicine, Aurora, CO, United States; 4Medicine, Nankai University, Tianjin, China; 5Medicine, University of California Los Angeles, Los Angeles, CA, United States; 6Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, United States Natural killer (NK) cells of the innate immune system can profoundly impact the development of adaptive immune responses against foreign invaders, as well as self-antigens. In this study a combination of in vivo MRI and bioluminescence imaging was used to investigate effects of systemic depletion of NK cells on lesion development in an experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis. The results of this study suggest organ-specific activity of NK cells on the magnitude of CNS inflammation. Imaging of Psychiatric Disorders Hall B Thursday 13:30-15:30 Ana Stan1, Perry Mihalakos2, Deborah Douglas3, Stephanie Morris2, Changho Choi3, Carol Tamminga2 1Western Psychiatric Institute and Clinic, University of Pittsburgh Medical Center, Pittsburgh, PA, United States; 2Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States; 3Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States We report a result of a 3T 1H-MRS study in schizophrenia. The concentrations of glutamate (Glu), glutamine (Gln), and N-acetylaspatate (NAA) in hippocampus (voxel 50x15x15 mm) were measured using a triple refocusing sequence. GABA was measured with a difference editing method. MRS scans were conducted on 13 schizophrenia volunteers (10 on medication (SV-ON) and 3 off-medication (SV-OFF)) and 14 normal volunteers (NV). LCModel fitting was used for spectral analysis. [Glu]/[Cr] was observed to be similar between NV and SV-ON (p = 0.4). However, [Glu]/[Cr] in SV-OFF was significantly lower (~30%) than in both NV and SV-ON (p = 0.02 and 0.04, respectively). For Gln, the concentrations were about the same between the three groups (p > 0.2). Compared to NV, [NAA]/[Cr] was reduced (by 10%) in SV-ON (p = 0.006), but not in SV-OFF (p = 0.55). The GABA data showed difference between SV-OFF and SV-ON (p = 0.05). Yu-Chun Lo1, Su-Chun Huang2, Hai-Gwo Hwu3, Chih-Min Liu3, Chen-Chung Liu3, Wen-Yih Isaac Tseng2,4 1Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, Taiwan; 2Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, Taiwan; 3Department of Psychiatry, National Taiwan University Hospital, Taipei, Taiwan; 4Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan Three association fibers connecting the frontal and temporal lobes and three commissural fibers connecting the bilateral orbitofrontal lobes, inferior frontal gyri, and superior temporal gyri related to the social and language functions that might serve the neuropsychopathology of patients with schizophrenia inferred from diffusion spectrum imaging tractography. In neurotypical participants, a consistent leftward asymmetry in the three pairs of association fibers was found. However, adults with schizophrenia did not demonstrate such asymmetry. Lack of leftward asymmetry in schizophrenia may imply a disruption in the normal pattern of structural and functional connectivity in frontal-temporal brain regions. Christine Rodriguez-Régent1, Sabine Mouchet-Mages2, Sebastian Rodrigo, Marie-Odile Krebs2, Catherine Oppenheim, Jean-Franēois Meder 1Department of Morphologic and Functional Imaging, University Paris Descartes, Sainte Anne Hospital, PARIS, France; 2Pathophysiology of Psychiatric Diseases, University Paris Descartes, Sainte Anne Hospital, PARIS, France Schizophrenic patients often present with neurological soft signs (NSS) but the cerebral changes underlying these signs are poorly understood. This study examines the microstructural changes associated with NSS using Diffusion Tensor Imaging. Forty-five patients with first-episode schizophrenia underwent DTI and a neurological examination. Fractional anisotropy (FA), calculated using a voxel based analysis, was analyzed with NSS scores. FA was negatively correlated with NSS scores in the white matter of the right prefrontal, left occipital and right parietal areas. Thus, this is the first study which confirms that microstructural changes of white matter are associated with NSS in schizophrenia. Florian Schubert1, Andreas Klaer2, Martina Ballmaier2, Karolina Leopold2, Ines Haeke2, Martin Schaefer3, Ruediger Bruehl1, Juergen Gallinat2 1Physikalisch-Technische Bundesanstalt, Berlin, Germany; 2Charite University Medicine, Berlin, Germany; 3Kliniken Essen, Essen, Germany We used single voxel 1H-MRS at 3 Tesla to measure absolute NAA concentrations and, as a gold standard of CNS volumetry, a validated delineation protocol for the hippocampus to study the interaction between between hippocampal NAA reduction and volume deficits in 29 schizophrenic patients and 44 controls. The hippocampus of the patients exhibited a significantly smaller volume and lower NAA concentration than that of healthy controls. For schizophrenic patients a significant negative correlation between hippocampal NAA concentration and volume was observed. The results argue for a coexistent neurochemical and structural deficit in the hippocampus of schizophrenic patients. 2143. An MRI Study of the Caudate Nucleus in Euthymic Bipolar I Disorder Louise Emsell1, Camilla Langan1, Sarah Hehir1, Helen Casey1, Wil van der Putten1, Peter McCarthy1, Rachel Skinner1, Dara M. Cannon1, Colm McDonald1 1NUI Galway, Galway, Ireland Bipolar disorder is a complex illness characterised by extremes of mood. It is likely that subtle changes in neuroanatomy contribute to the underlying aetiopathology of the disorder. This study sought to identify differences in the volume of the caudate nucleus in a prospectively confirmed sample of 59 remitted patients compared to 59 individually age and gender matched healthy controls to identify trait related anatomical changes. We did not find a main of effect of diagnosis. However,we did detect gender differences in caudate volume (F>M),age-related volumetric decrease across the study population and a main effect of family history in patients. Wolfgang Weber-Fahr1, Mathias Zink2, Andreas Meyer-Lindenberg2, Monika Uhrig1, Nuran Tunc-Skarka1, Mareen Hoerst1, Helga Welzel-marquez1, Alexander Sartorius2, Gabriele Ende1 1Neuroimaging, Central Institute of Mental Health, Mannheim, NA, Germany; 2Dept. Psychiatry, Central Institute of Mental Health, Mannheim, NA, Germany A 3D-whole head RINEPT sequence was used together with point-spread function corrected tissue segmentation for robust absolute quantification of spectral edited Phosphomono- and diester-signals in the brains of schizophrenic patients and controls. The corrected metabolite concentrations show a significant reduction of Phosphocholine and Glycerophosphocholine (GPC) in the basal ganglia and thalamus of schizophrenic patients compared to controls. GPC was also significantly lower in the cerebellum while Phosphorylethanolamine showed a trend for lower concentration in patients in the frontal region. 2145. Altered Fiber Radial Diffusivity in Schizophrenia Revealed by HARDI Xin Hong1,2, Lori R. Arlinghaus3, Herbert Y. Meltzer4, Sohee Park5, Adam W. Anderson, 2,3 1Institute of Imaging Science, Vanderbilt University , Nashville, TN, United States; 2Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States; 3Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 4Department of Psychiatry, Vanderbilt University, Nashville, TN, United States; 5Department of Psychology, Vanderbilt University, Nashville, TN, United States We performed a group comparison of the diffusion properties and intravoxel fiber coherence estimated by FORECAST analysis. Significantly higher FA is found in schizophrenia patients compared to healthy controls in the left superior longitudinal fasciculus and bilateral internal capsules. In all three regions, strong negative correlation between FA and radial diffusivity is found at both voxel and cluster levels, even after controlling for coherence variation. Significantly lower coherence is found between the two groups at the cluster level, but not voxel level. Our results suggest the altered FA was mainly due to structural rather than organizational changes in these regions. John DeWitt Port1, Ileana Hancu2, Heidi Alyssa Edmonson1, Zhonghao Bao3, Mark A. Frye4 1Radiology, Mayo Clinic, Rochester, MN, United States; 2GE Global Research Center, Niskayuna, NY, United States; 3Information Services, Mayo Clinic, Rochester, MN, United States; 4Psychiatry, Mayo Clinic, Rochester, MN, United States Various methods have been used to correct for the amount of CSF within spectroscopic voxels. However, it remains unclear which method is best. We performed CSF correction on an MRS dataset comparing depressed psychiatric patients to normal controls, using the ratio to creatine as well as two anatomically-based CSF correction methods. All three CSF correction methods yielded significant results for most statistical comparisons; ROC analysis demonstrated no single CSF correction technique to be better than the others. If the metabolite value used in the denominator is stable, ratios may actually improve statistical sensitivity relative to anatomically-based CSF correction methods. 2147. fMRI and Connectivity Effects of Electro-Convulsive Therapy (ECT) in Depressed Patients Erik B. Beall1, Mark J. Lowe1, Michael D. Phillips1, Steve Jones1, Pallab K. Bhattacharyya1, David Muzina2 1Radiology, Cleveland Clinic, Cleveland, OH, United States; 2Psychiatry, Cleveland Clinic, Cleveland, OH, United States ECT is a safe and effective treatment for depression. However its mechanisms have not been studied with the BOLD effect in a pre- and post-ECT fMRI and connectivity study. We present preliminary results that show reduced activation and connectivity in response to working memory and affective tasks. 2148. Decreased Anterior Cingulate Cortex GABA in Depressed Adolescents Measured by Proton MRS at 3T Vilma Gabbay1, Xiangling Mao2, Yisrael Katz1, Aviva Pazner1, James S. Babb1, Dikoma C. Shungu2 1NYU Child Study Center, NYU School of Medicine, New York, NY, United States; 2Radiology, Weill Cornell Medical College, New York, NY, United States Adolescent major depressive disorder (MDD) is a serious public health concern as it often leads to suicide. However, limited research has been conducted to date in this clinical population. This is the first study to examine in vivo γ-aminobutyric acid (GABA) in adolescents with MDD. Using proton MRS, levels of GABA were measured in the anterior cingulate cortex of adolescents with MDD and found to be decreased compared to matched healthy control subjects. This finding supports the notion that GABA abnormalities may be involved early in the etiology of MDD. Ilya M. Veer1,2, Christian F. Beckmann3,4, Evelinda Baerends1,2, Marie J. van Tol1,5, Luca Ferrarini6, Julien R. Milles6, Dick J. Veltman7, Andre Aleman8, Mark A. van Buchem1,2, Nic J. van der Wee1,5, Serge A. Rombouts1,2 1Leiden Institute for Brain and Cognition (LIBC), Leiden, Netherlands; 2Department of Radiology, Leiden University Medical Center (LUMC), Leiden, Netherlands; 3FMRIB, University of Oxford, Oxford, United Kingdom; 4Department of Clinical Neuroscience, Imperial College London, London, United Kingdom; 5Department of Psychiatry, Leiden University Medical Center (LUMC), Leiden, Netherlands; 6Department of Radiology, Division of Image Processing, Leiden University Medical Center (LUMC), Leiden, Netherlands; 7Department of Psychiatry, Free University Medical Center (VUMC), Amsterdam, Netherlands; 8BCN Neuroimaging Center, University of Groningen, Groningen, Netherlands Major depression is associated with abnormal function of a large-scale mood processing and regulating brain circuit of interconnected regions. Therefore, resting-state (RS) functional connectivity networks were investigated in a group of 19 medication-free patients diagnosed with major depressive disorder without comorbidity, and 19 age- and gender-matched healthy controls. Using independent component, 13 relevant RS networks were found for the entire group. Adopting a dual regression method, subject specific maps were calculated and subsequently used for permutation analysis. We found decreased functional connectivity in three networks, which may relate to the affective and cognitive symptoms in major depression. 2150. Investigating Transverse Relaxation Time Abnormalities in Autism Yann Gagnon1,2, N Rajakumar3, Neil Gelman1,2, Peter Williamson3, Dick Drost1,2, Jean Théberge1,2, Rob Nicolson3 1Imaging, Lawson Health Research Institute, London, Ontario, Canada; 2Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 3Psychiatry, University of Western Ontario Quantitative transverse relaxation time (T2) imaging offers a unique opportunity to evaluate the neurobiology of brain tissue. In the current study, we further localize our previously reported overall white matter T2 increase in a sample of children with autism to developmentally relevant neuroanatomic white matter regions. Chun-Wei Lan1, Kun-Hsien Chou2, I-Yun Chen3, Ya-wei Cheng3, Jean Decety4, Yang-Teng Fan3, Ching-Po Lin1,3 1Institute of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan; 2Institute of Biomedical Engineering, National Yang Ming University, Taipei, Taiwan; 3Institute of Neuroscience, National Yang Ming University, Taipei, Taiwan; 4Departments of Psychology and Psychiatry, The University of Chicago, Chicago, United States The autism spectrum disorders (ASD), during childhood, undergoes precocious growth, followed by maturation deceleration. But how the ASD brain changed during adolescence is unclear. We enrolled 25 male adolescents with ASD and 25 controls for voxel-based morphometric analysis. Global brain volume enlargement of ASD did not persist into adolescence. The right inferior parietal lobule and posterior cingulate cortex, a role in social cognition, had a significant interaction of age by group as indicated by an accelerated age-related loss in the adolescents with ASD but an age-related gain in the controls. The findings provided evidence of aberrant neurodevelopment in ASD. Sung-Yeon Park1, Se-Hong Oh1, Hyo-Woon Yoon1, Young-Bo Kim1, Zang-Hee Cho1, Keun-Ah Cheon2 1Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Korea, Republic of; 22Division of child and Adolescent Psychiatry, Department of Psychiatry, Kwandong University College of Medicine, Kyunggi-Do, Korea, Republic of Autism spectrum disorders (ASD) are characterized by qualitative impairments of reciprocal social interaction and deficits in communication, and stereotyped or repetitive pattern of behavior. A few reports have shown the abnormalities of white matter in autism using diffusion tensor imaging (DTI), however there is still lack of evidence showing strong relation to abnormalities in white matter structural integrity with autism. We enrolled thirty four male subjects (17 ASD, 17 healthy controls, matched on age, IQ, handedness.). Our preliminary findings which showed significant reduction of FA in white matter structure related social cognition in ASD subjects compared control subjects support previous findings that social brain structure may be disrupted in ASD. These findings will help on understanding of more advanced neurobiological basis underlying the social deficits in ASD. 2153. Imaging Myelin in Autism Janneke Zinkstok1, Eileen Daly1, Christine Ecker1, Patrick Johnston1, Shannon Kolind2, Declan Murphy1, Sean Deoni2 1Section of Brain Maturation, Institute of Psychiatry, London, United Kingdom; 2Centre of Neuroimaging Sciences, Institute of Psychiatry, London, United Kingdom Using the novel Multi-Component Driven Equilibrium Single Pulsed Observation of T1 and T2 (mcDESPOT) method, we quantitatively compared myelin content between individuals with autism and healthy controls. We found significantly reduced myelin content in adults with autism in brain regions previously implicated in autism, including the body of the corpus callosum, and in frontal, temporal, parietal and occipital regions; and in white matter tracts including the left and right uncinate, the left inferior occipitofrontal tract, the left inferior cerebellar peduncle, the left arcuate, the right anterior segment, the left inferior and superior longitudinal fasciculus, and the posterior segments bilaterally. 2154. Inter-Subject Comparison of Fractional Anisotropy in Attention-Deficit/hyperactivity Disorder Tzu-Chao Chuang1, Sheng-Po Huang1, Pinchen Yang2, Ming-Ting Wu3,4 1Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan, Taiwan; 2Psychiatry, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, Taiwan; 3School of Medicine, National Yang-Ming University, Taipei, Taiwan, Taiwan; 4Radiology, Kaohsiung Veteran General Hospital, Kaohsiung, Taiwan, Taiwan In this study, white matter abnormalities of attention-deficit hyperactivity disorder were investigated using diffusion tensor imaging. Two different algorithms, including the well-known voxel-based morphometry (VBM) method and recently proposed tract-based spatial statistics (TBSS), were applied for inter-subject comparison. 26 male adolescents (12 ADHD patients and 14 age-matching control subjects) were recruited in this study. Significant decrease of FA was observed on white matter tracts widespread in a scattering pattern by the use of both methods in patients compared to the control group. Lawrence Steven Kegeles1,2, H. Blair Simpson1, Xiangling Mao3, Rena Staub1, Dikoma C. Shungu3 1Psychiatry, Columbia University, New York, NY, United States; 2Radiology, Columbia University, New York, NY, United States; 3Radiology, Weill Cornell Medical Center, New York, NY, United States This MRS study addressed GABA and glutamate-glutamine levels in a hypothesized abnormal neurochemical circuit in obsessive-compulsive disorder (OCD). Recent animal and human studies have implicated the glutamate system in OCD in these abnormalities. We used the J edited spin echo difference method to evaluate glutamate-glutamine and GABA in two frontal cortical regions, the anterior cingulate and dorsolateral prefrontal cortex in OCD. We found no differences between OCD subjects and controls in either measure in either brain region, suggesting that further studies are needed to fully characterize the neurochemistry of the hypothesized abnormal circuitry in OCD. 2156. Impaired Default-Mode Networks of Affective Disorders: Evidences of Image-Guided Proton MRS Tzu-chen Yeh1,2, Chih-Ying Lin2, Cheng-Wen Ko3, Ton-Ping Su4, Wan-Yuo Guo5, Jen-Chuen Hsieh2, Low-Ton Ho1 1Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan, Taiwan; 2Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan, Taiwan; 3Department of Computer Science and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan, Taiwan; 4Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan, Taiwan; 5Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, Taiwan The spatial template of default-mode network (DMN) has been constructed and shown precuneus/posterior cingulate areas (PC, Brodmann area 31) with highest reproducibility in 60 normal subjects. High resting metabolic rate of DMN was implied by previous deoxy-glucose positron emission tomography. In this study of affective disorders (bipolar and major depressive disorders), bioenergetics of Brodmann area 24 and DMN was probed by total creatine using real-time localized image-guided proton magnetic resonance spectroscopy (ig-HMRS) and LCModel quantification. As compared to affective disorders, higher metabolism of PC (representing DMN) in normal subjects was supported by higher total creatine concentration. Mareen Hoerst1,2, Wofgang Weber-Fahr1, Nuran Tunc-Skarka1, Matthias Ruf1, Martin Bohus2, Christian Schmahl2, Gabriele Ende1 1Department of Neuroimaging, Central Institute of Mental Health, Mannheim, Germany; 2Department of Psychosomatic Medicine and Psychotherapy, Central Institute of Mental Health, Mannheim, Germany Dysfunction and deficits in the structure of the anterior cingulate cortex (ACC) have been reported in borderline personality disorder (BPD). Impulsivity belongs to the key features of BPD and can be related to ACC function. In this study we found significantly increased self-reported impulsivity and higher levels of glutamate in the anterior cingulate cortex in subjects with BPD as compared to healthy controls. In both groups the ACC glutamate concentrations were positively correlated with self-reported impulsivity. Natalia del Campo1,2, Julio Acosta-Cabronero3,4, Samuel R. Chamberlain, Dowson Jonathan5, Tim D. Fryer, 4, Trevor W. Robbins, Barbara J. Sahakian5, Ulrich Muller 1Psychiatry, University of Cambridge, Cambridge, Cambs, United Kingdom; 22Behavioural and Clinical Neuroscience Institute, Cambridge, Cambs, United Kingdom; 3Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom; 4Wolfson Brain Imaging Centre; 5Department of Psychiatry Attention deficit/hyperactivity disorder (ADHD) is the most prevalent psychiatric disorder in children. To date, little is known about the persistence and stability of anatomical changes in ADHD across the lifespan. 16 adult ADHD patients and 17 healthy controls undertook structural magnetic resonance imaging. Using cluster-based permutation analysis we found that ADHD patients had reduced grey matter density in distributed circuitries including the right inferior and middle frontal cortex, as well as bilateral putamen, hippocampus, amygdala and cerebellum. These findings add to a growing body of evidence implicating abnormalities in fronto-striatal, fronto-cerebellar and limbic circuitries in ADHD. Cheng-Liang Liu1, I-Chao Liu2, Wen-Yang Chiang3, Fang-Cheng Yeh4, Li-Wei Kuo1, Wen-Yih Isaac Tseng1,5 1Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan; 2School of Medicine, Fu Jen Catholic University, Taipei, Taiwan; 3The Methodist Hospital Research Institute, Weill Medical College of Cornell University, Houston, TX, United States; 4Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States; 5Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan In this study, we investigated the relationship between the effect of alcoholic use and the microstructural alteration of seven association fiber tracts using diffusion spectrum imaging tractography and tract-specific analysis. The metric of generalized fractional anisotropy (GFA) was used to identify the difference between control and alcoholic groups. Among all the association fiber tracts, a significant GFA deficit was found in bilateral superior longitudinal fasciculus for chronic alcoholics. A future study to analyze the segmented parts of the tract is needed to further reveal the subtle change of microstructural alteration of association fiber tracts in alcoholism. Gabriele Ende1, Derik Hermann2, Mareen Hoerst1, Nuran Tunc-Skarka1, Gunilla Oberthuer1, Svenja Wichert2, Juri Rabinstein2, Wolfgang Weber-Fahr1, Karl Mann2, Sabine Vollstaedt-Klein2 1Neuroimaging, Central Institute of Mental Health, Mannheim, Germany; 2Addiction Medicine, Central Institute of Mental Health, Mannheim, Germany With this 1H MRS study we aimed to investigate correlations between frontal white matter choline-containing compounds and glutamate with alcohol consumption and addictions scores in heavy drinking as well as in non-abstinent alcohol dependent patients. A positive correlation of choline-containing compounds and alcohol consumption could be replicated but the high variance could not be explained by addiction criteria (OCDS, ICD-10 and DSM IV). However, measures of addiction showed significant negative correlations with glutamate in the heavy drinking groups. 2161. Test and Retest of the Emotional Responses in Adolescents Prenatally Exposed to Cocaine Zhihao Li1, Priya Santhanam1, Claire D. Coles2, Mary Ellen Lynch2, Stephan Hamann3, Xiaoping Hu1 1Biomedical Engineering, Emory Univ. & Georgia Tech., Atlanta, GA, United States; 2Psychiatry and behavioral Science, Emory Univ., Atlanta, GA, United States; 3Psychology, Emory Univ., Atlanta, GA, United States The present fMRI study examined the interaction effect of prenatal cocaine exposure (PCE) and development on brain activations associated with emotional arousal, in adolescents. Comparing age 17 to 15, cortical responses elicited by negative emotional stimuli are reduced in the controls but remain roughly the same in the PCE adolescents. The present results suggest a long-term and stable PCE effect on emotional arousal regulation. 2162. Altered Cortical Thickness in Young Cannabis Abusers Deborah Yurgelun-Todd1,2, Piotr Bogorodzki3, Melissa Lopez-Larson1,2, Robert Kurjata3, John Churchwell1, Jadwiga Rogowska4 1Brain Institute, University of Utah, Salt Lake City, UT, United States; 2VISN 19 MIRECC, Salt Lake City, UT, United States; 3Institute of Radioelectronics, Warsaw Technical University, Warsaw, Poland; 4Brain Imaging Center, McLean Hospital/Harvard Medical School, Belmont, MA, United States It is unknown whether altered cortical thickness during adolescence is associated with marijuana (MJ) use. This investigation used cortical-surface based techniques to compare MJ using adolescents and healthy controls (HC). Eighteen adolescents with DSM-IV MJ Dependence and 18 HCs had an MRI scans using a 3T Siemens Trio scanner. Cortical reconstruction and volumetric segmentation was performed with the Freesurfer image analysis suite. Compared to HCs, MJ users had decreased cortical thickness in bilateral superior frontal cortex and bilateral and left insula. Furthermore, the average thickness of the right insula was found to negatively correlate with age of first MJ use. 2163. Perfusion Deficit to Cholinergic Challenge in Veterans with Gulf War Illness Peiying Liu Wang1, Sina Aslan1, Xiufeng Li2, David Buhner3, Richard Briggs2, Robert Haley3, Hanzhang Lu1 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States; 3Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States A highly plausible etiology for the Gulf War Illness (GWI) is that the neural damage and cognitive deficits are associated with excessive exposure to cholinesterase-inhibiting cholinergic stimulants. Our previous SPECT study provided strong indication that cerebral blood flow of veterans with Syndrome 2 GWI has reduced responses to cholinergic challenge, compared to unaffected control veterans. The present study confirmed and extended previous findings that patients with Gulf War Illness have abnormal response to an inhibitory cholinergic challenge, physostigmine infusion, when compared to age-gender-education matched control veterans. This new technique may provide a cost-effective biomarker for characterization of Gulf war illness. 2164. Cortical GABA and Glutamate Changes in Posttraumatic Stress Disorder Anderson Mon1,2, Thomas Neylan3, Dieter Meyerhoff1,4 1Radiology, University of California, San Francisco, San Francisco, CA, United States; 2Center for Imaging of Neurodegenerative Diseases, Veteran Administration Medical Center, San Francisco, CA; 3Psychiatry, University of California, San Francisco, San Francisco, CA, United States; 4Center for Imaging of Neurodegenerative Diseases, Veteran Administration Medical Center, San Francisco, CA, United States We studied NAA, Glu and GABA levels in post traumatic stress disorder using magnetic resonance spectroscopy. We found lower NAA in the anterior cingulate, lower GABA in the posterior occipital cortex, and lower GABA and higher Glu in the medial temporal lobe as compared to control subjects. Metabolite levels related to PTSD symptomatology and suggest neuronal injury, perhaps associated with excitatory and inhibitory processes in cortical brain Clinical Brain Tumor Imaging: Anatomic, MT, SWI & Perfusion MRI Hall B Monday 14:00-16:00 Gerard Thompson1,2, Sha Zhao1,2, Samantha J. Mills1,2, John R. Cain1,2, Geoff J M Parker1,2, Alan Jackson1,2 1Imaging Science and Biomedical Engineering, University of Manchester, Manchester, United Kingdom; 2Biomedical Imaging Institute, University of Manchester, Manchester, United Kingdom Glioblastoma multiforme is an aggressive primary brain tumour, which invades preferentially along white matter tracts. Histopathological and PET evidence suggests that at the time of diagnosis, infiltrating tumour already exists at sites distant from the enhancing tumour visible on conventional anatomical MR imaging. Since MR is used to plan radiotherapy and surgery, there is concern that infiltrating tumour may be missed, and may therefore escape optimal treatment. We provide preliminary evidence in two cases that quantitative magnetisation transfer (qMT) imaging can detect changes in white matter adjacent to glioblastoma which appear otherwise normal on conventional MR imaging. Leland S. Hu1,2, Seban Liu3, Dilini S. Pinnaduwage4, Kris A. Smith5, Peter Nakaji5, Amylou C. Dueck6, Todd Jensen7, Jennifer M. Eschbacher8, Joseph E. Heiserman2, John P. Karis2, Josef Debbins3, Burt G. Feuerstein9, Kathleen M. Schmainda10, Leslie C. Baxter3 1Radiology, Mayo Clinic, Arizona, Scottsdale, AZ, United States; 2Radiology, Neuroradiology Section, St. Joseph's Hospital - Barrow Neurological Institute, Phoenix, AZ, United States; 3Keller Center for Imaging Innovation, St. Joseph's Hospital - Barrow Neurological Institute, Phoenix, AZ, United States; 4Radiation Oncology, University of California - San Francisco, San Francisco, CA, United States; 5Neurosurgery, St. Joseph's Hosptial - Barrow Neurological Institute, Phoenix, AZ, United States; 6Biostatistics, Mayo Clinic, Arizona, Scottsdale, AZ, United States; 7Imaging Biometrics, LLC; 8Neuropathology, St. Joseph's Hospital - Barrow Neurological Institute, Phoenix, AZ, United States; 9Neuro-Oncology, St. Joseph's Hospital - Barrow Neurological Institute, Phoenix, AZ, United States; 10Radiology, Medical College of Wisconsin, Milwaukee, WI, United States We present methods to calculate Perfusion MRI (pMRI) fractional tumor bulk, which quantifies and spatially localizes areas of tumor recurrence within non-specific contrast enhanced (CE) MRI lesions. We correlate these measures with the percentage, or fraction, of tissue samples histopathologically diagnosed as tumor, in a group of recurrent Glioblastoma Multiforme (GBM) patients undergoing multiple stereotactic biopsies. Slim Fellah1, Yann Lefur1, Elisabeth Soulier1, Céline Boucard2, Sylviane Confort-Gouny1, Olivier Chinot2, Patrick J. Cozzone1, Jean-Philippe Ranjeva1, Virginie Callot1 1Centre de Résonance Magnétique Biologique et Médicale (CRMBM), CNRS UMR 6612, Faculté de Médecine, Marseille, France; 2Unité de Neuro-Oncologie, CHU Timone, Marseille, France Anti-angiogenics have become part of Glioblastoma therapeutic protocol. However pseudo-response followed by a critical recurrence may be observed. Non-responders thus need to be prematurely identified. However current imaging criteria are insufficient or late, new MR markers should therefore be investigated. In this preliminary study, we used a multimodal protocol including particularly ASL and SWI, which provide vascular information. A few weeks after the beginning of the treatment, FLAIR and post-contrast T1-WI showed partial response whereas perfusion MRI and SWI demonstrated hyperperfusion and vascularization increase. The parameters derived from such sequences should thus be considered as early indicators of tumor evolution.
Kyrre E. Emblem1,2, Paulina Due-Tonnessen1,3, Inge A. Rasmussen Jr1, Atle Bjornerud2,4 1The Interventional Centre, Rikshospitalet, Oslo University Hospital, Oslo, Norway; 2Department of Medical Physics, Rikshospitalet, Oslo University Hospital, Oslo, Norway; 3Clinic for Imaging- and Intervention, Rikshospitalet, Oslo University Hospital, Oslo, Norway; 4Department of Physics, University of Oslo, Oslo, Norway In this study, a fully-automatic method for longitudinal monitoring of low-grade glioma transformation by quantitative dynamic susceptibility contrast (DSC) MRI was evaluated and compared to conventional criteria for malignant glioma progression. Thirteen patients were imaged at least three times, with an average time between two consecutive MR exams of 283 days. Our results suggest that the fully-automatic method provides a sensitive marker for tumor progression at an early stage compared to conventional imaging criteria. Also, the quantitative tumor analysis and monitoring of baseline perfusion values in unaffected brain tissue, allows inter- and intra-patient comparisons across MR machines and institutions. Janine M. Lupo1, Soonmee Cha1, Emma Essock-Burns1,2, Nicholas Butowski3, Sarah J. Nelson1,2 1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, United States; 3Department of Neurosurgery, University of California, San Francisco, San Francisco, CA, United States This study investigated whether the unique contrast provided by SWI, which highlights heterogeneity within the post-gadolinium contrast enhancing brain tumor lesion, can predict response to treatment. Nineteen patients with newly-diagnosed GBM were imaged prior to beginning anti-angiogenic, cytotoxic, and radiation therapy and followed until progression. The volume of SWI hypointense signal within the contrast-enhancing lesion was dramatically higher in patients who progressed after 1 year post-therapy compared to patients who progressed within 6 months of initiating treatment. These findings suggest that SWI could be advantageous for determining which patients would be the best candidates for adjuvant anti-angiogenic therapeutic strategies.
Emma Essock-Burns1,2, Yan Li1, Janine M. Lupo1, Mei-Yin Polley3, Nicholas Butowski3, Susan M. Chang3, Soonmee Cha, 1,3, Sarah J. Nelson1,4 1Department of Radiology and Biomedical Imaging, UC San Francisco, San Francisco, CA, United States; 2Joint Graduate Group in Bioengineering, UC San Francisco/UC Berkeley , San Francisco, CA, United States; 3Department of Neurological Surgery, UC San Francisco, San Francisco, CA, United States; 4Department of Bioengineering and Therapeutic Sciences, UC San Francisco, San Francisco, CA, United States Adjuvant anti-angiogenic therapy may alter the presentation of contrast enhancement creating a clinical need for new methods of evaluating response. Dynamic susceptibility contrast enhanced imaging was used to assess vascular changes of patients newly diagnosed with GBM in response to either conventional (XRT+cytotoxic) or adjuvant anti-angiogenic therapy. A decrease in vascularization was observed early in adjuvant anti-angiogenic therapy. Progression-free survival status of patients receiving anti-angiogenic therapy may be dominated by an initial change in leakage, while PFS of patients receiving conventional therapy is not. This work highlights the need for further functional imaging techniques for the evaluation of response. Christina Tsien1, Craig J. Galban1, Thomas L. Chenevert1, Timothy D. Johnson1, Daniel A. Hamstra1, Pia C. Sundgren1, Larry Junck1, Charles R. Meyer1, Alnawaz Rehemtulla1, Theodore Lawrence1, Brian D. Ross1 1University of Michigan, Ann Arbor, MI, United States We have developed a reliable method for distinguishing true progression from pseudoprogression by quantifying on a voxel-wise basis therapeutic-associated hemodynamic alterations in patients with high grade glioma. The parametric response map of rCBV (PRMrCBV) at week 3 during chemoradiation is shown to be a potential early imaging biomarker of response that may be helpful in distinguishing pseudoprogression from true progression in patients with high grade glioma. Yue Cao1, Felix Y. Feng, Diana Gomez-Hassan2, James A. Hayman, Theodore S. Lawrence, Christina I. Tsien 1Radiology and Radiation Oncology, University of Michigan, Ann Arbor, MI, United States; 2Radiology, University of Michigan, Ann Arbor, MI, United States The response of metastatic lesions to whole brain radiation therapy (WBRT) is highly heterogeneous. In this study, we evaluated quantitative metrics derived from DCE MRI for early assessment of response of brain metastatic lesions to WBRT. We found that changes in vascular volume and perfusion at the completion of WBRT differentiated responsive lesions from non-responsive ones. These DCE metrics have the potential for early prediction of treatment response in brain metastases. This requires further validation, but may provide a means for individualizing therapy in patients with brain metastases by selecting patients requiring treatment intensification with stereotactic RT. Muftah Ahmed Manita1, Paul Morgan2, Keith Robson3, Timothy Jaspan3, Dorothee P. Auer1 1Academic Radiology, University of Nottingham, Nottingham, United Kingdom; 2Radiology & Radiological Science, Medical University of South Carolina, United States; 3Nottingham University Hospital, United Kingdom Perfusion MRI DSC (T2*) has shown added values in glioma tumour differentiation with rCBVmax is the best performing metrics obtained from dynamic susceptibility contrast technique (DSC). However, this technique is susceptible to blood leak that results in rCBV overestimation. T1 MRI perfusion (DCE) is not susceptible to vascular disruption. Nineteen patients with low and high grade glioma underwent MR perfusion (T1 and T2*) was analysed with Java image software. Significant difference (P=0.000) with excellent correlation (0.81) between the two tumour grades in both techniques with accuracy of 100%. T1 based DCE is robust technique to follow postoperative cases. 2174. Enhancing Fraction and Survival in Glioblastoma Multiforme Samantha Jane Mills1,2, Calvin Soh2, Gerard Thompson1, Giovanni Buonaccorsi1, Catherine McBain3, Sha Zhao1, Geoff James Martin Parker1, Alan Jackson1,2 1Imaging Science and Biomedical Engineering, University of Manchester, Manchester, Greater Manchester, United Kingdom; 2Department of Neuroradiology, Salford Royal Foundation Trust Hospital, Salford, Greater Manchester, United Kingdom; 3Department of Clinical Oncology, Christie Hospital, Manchester, Greater Manchester, United Kingdom This study describes the relationship between the DCE-MRI derived measure, Enhancing Fraction, and overall survival in patients with Glioblastoma Multiforme, with the findings of increased survival in association with elevated Enhancing Fraction. Imaging of Brain Tumors: Techniques & Contrast Media Hall B Tuesday 13:30-15:30 2175. Delta T1 Method: An Automatic Post-Contrast ROI Selection Technique for Brain Tumors Devyani Bedekar1,2, Todd Jensen3, Scott Rand1,4, Mark Malkin, 2,5, Jennifer Connelly, 2,5, Kathleen Schmainda, 2,6 1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States; 2Translational Brain Tumor Research Program, Medical College of Wisconsin, Milwaukee, WI, United States; 3Imaging Biometrics, Milwaukee, WI, United States; 4Translational Brain Tumor Research Program, Medical College of Wisconsin, Milwaukee, WI, United States; 5Neurology, Medical College of Wisconsin, Milwaukee, WI, United States; 6Radiology & Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States The primary approach to monitoring patients with brain tumors is to obtain pre and post-contrast T1-weighted images. Bright areas on the pre-contrast images are suggestive of blood products, which may be a result or treatment, and are therefore not to be considered as enhancing lesions on the post-contrast images. However, the difference between the brightness that exists on both the post and pre-contrast images can be quite subtle, a condition that is occurring more frequently now with the increasing use of anti-angiogenic agents. Therefore it is becoming increasingly difficult to monitor patients with brain tumors simply by visually comparing differences in enhancement. As a solution in this report we propose an automatic method, the delta T1 method (dTM), which is capable of detecting even subtle enhancing tumor free of blood products, thereby enabling the automatic creation of ROIs in a fast and reliable manner that avoids subjective variability. Meritxell Garcia1, Monika Gloor2, Christoph Stippich1, Felix Jax1, Klaus Scheffler2, Oliver Bieri2 1Department of Neuroradiology, University of Basel Hospital, Basel, Switzerland; 2Radiological Physics, University of Basel Hospital, Basel, Switzerland The efficacy of quantitative MT (qMT) imaging for characterization of benign and malignant brain lesions is analyzed with balanced steady-state free precession. Eleven patients with 3 different lesions (4 glioblastoma multiforme, 4 meningeomas and 3 metastases) were investigated on a clinical 1.5T MR-scanner. MT-effects are described in terms of MTR, relaxation times (T1, T2), MT exchange rate (kf) and the macromolecular content (F). Marked divergences between contrast-enhancing regions, edema and normal-appearing brain were found within and between the different lesions, which might be attributed to differences in edema, cell infiltration and myelin properties. Thus, qMT-imaging might play a major role in adding information for diagnostic tumor characterization. 2177. Magnetic Resonance Imaging Contrast of Brain Tumors at 7 Tesla Compared to 3 Tesla Iris-Melanie Noebauer-Huhmann1, Pavol Szomolanyi1,2, Claudia Kronnerwetter1, Siegfried Trattnig1 1MR Centre - High field MR, Department of Radiology, Medical University of Vienna, Vienna, Austria; 2Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia It is well known that the effect of MR contrast agents is influenced by the magnetic field strength. The aim of the study was to compare the diagnostic efficacy of a Gadolinium-based MRI contrast agent (gadobenate dimeglumine) in primary brain tumors at 7Tesla versus 3Tesla. Post contrast MP-RAGE sequences were evaluated by region of interest measurements. At 7Tesla, the tumor-to-brain-contrast after gadolinium administration was significantly higher (91.4) than at 3Tesla (37.3). Further studies will show if the higher tumor-to-brain-contrast post gadolinium administration at 7Tesla may be beneficial for tumors with minor contrast agent accumulation, or allow for a dose reduction. 2178. Ultra-High Field MRI of Primary Brain Tumors: Contrast and Resolution Fernando Emilio Boada1, Yongxian Qian1, Frank Lieberman2, Denise Davis1, Ronald Hamilton3 1MR Research Center, University of Pittsburgh, Pittsburgh, PA, United States; 2Neurooncology, University of Pittsburgh, Pittsburgh, PA, United States; 3Department of Neuropathology, University of Pittsburgh, Pittsburgh, PA, United States Imaging of primary brain tumors at Ultra-High Field (UHF) magnetic resonance imaging (MRI) has tremendous appeal due to the expected improvements in contrast at spatial resolution scales previously unpractical for in vivo human MRI. In this work we demonstrate the use of UHF for evaluating the microvascular structure of brain tumors and the improvements in signal quantification during sodium MRI Jannie Petra Wijnen1, Tom W.J. Scheenen1, Arend Heerschap1 1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands We demonstrated the clinical feasibility of combined 1H and 31P MRSI with sensitivity enhancement by polarisation transfer of 1H to 31P spins of human brain tumours at 3T to uncover the composition of (phosphorylated)choline and phosphorylated ethanolamine compounds in the membrane. Preliminary results from 4 patients with different tumour types show potentially important differences among tumours. This opens a window on a detailed view of the levels of some key metabolites in membrane phospholipid metabolism of human tumours. 2180. Multi-Echo Time Approach for Study of Metabolic Profiles in Brain Tumors at 3T Changho Choi1, Ivan Dimitrov1,2, Deborah Douglas1, Aditya Patel1, Hao Huang1, Ralph Deberardinis3, Juan Pascual4, Robert Bachoo5, Craig Malloy1, Elizabeth Maher6 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Philips Medical Systems, Cleveland, OH, United States; 3Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States; 4Neurology, Physiology and Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States; 5Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States; 6Internal Medicine and Neurology, University of Texas Southwestern Medical Center, Dallas, TX, United States Echo time dependence of coupled-spin metabolites following point-resolved spectroscopy (PRESS) at 3T has been investigated with computer simulations. Three pairs of PRESS subecho times, (TE1, TE2) = (32, 22), (32, 80), and (32, 214) ms, were selected for optimum selectivity of glutamate and glutamine, and used for in vivo measurements of metabolites in brain tumors. We present preliminary in vivo results that show pronounced abnormalities of metabolic profiles, including elevated glutamine and glycine in glioblastoma multiforme and differentiation between lipids and lactate in low- and high-grade gliomas. 2181. In Vivo MRI of MR-Labeled Neural Stem Cell Migration to Gliomas Bensheng Qiu1, Daohai Xie2, Piotr Walczak3, Xubin Li, Jesus Ruiz-Cabello3, Satoshi Minoshima, Jeff W.M. Bulte3, Xiaoming Yang 1University of Washington, Seattle, WA, United States; 2Radiology, Suzhou University School of Medicine; 3The Johns Hopkins University Neural stem cells (NSC) have been recognized as cellular vehicles for treatment of invasive brain tumors. MRI is a unique non-invasive tool to monitor the migration of stem cells labeled with MR contrast agents, such as superparamagnetic iron oxide (SPIO) particles. Pervious studies have confirmed that magnetosonoporation (MSP) can instantly labeled SPIO into stem cells. The aim of this study was to validate the feasibility of MRI of MSP-labeled NSC migration to gliomas in vivo. 2182. The Effect of Fiber Affinity on Predicted Cancer Cell Migration Based on MR-DTI Anitha Priya Krishnan1, Delphine Davis2,3, Paul Okunieff3, Walter G. O'Dell, 1,3 1Biomedical Engineering, University of Rochester, Rochester, NY, United States; 2Imaging Sciences, University of Rochester, Rochester, NY, United States; 3Radiation Oncology, University of Rochester, Rochester, NY, United States The current methods for determining the treatment margin for Stereotactic Radiotherapy of gliomas are inadequate as recurrences often occur at the boundary of the treatment margin. We developed a random walk model to determine the microscopic spread of tumor cells to facilitate in the development of anisotropic treatment margins. In this study we have shown that the affinity of cancer cells to fibers in the brain can be modeled better by the spread in the direction of migration about the Principal Diffusion Direction determined using DTI than by using a variable step-size in the random walk of cancer cells. Anitha Priya Krishnan1, Delphine Davis2, Paul Okunieff3, Walter G. O'Dell3 1Biomedical Engineering, University of Rochester, Rochester, NY, United States; 2Imaging Sciences, University of Rochester, Rochester, NY, United States; 3Radiation Oncology, University of Rochester, Rochester, NY, United States The current methods for determining the treatment margins for stereotactic radiotherapy of gliomas is inadequate as the tumor often recurs at the boundary of the treatment margin. The areas of high normalized cell migration predicted by our random walk model coincide with the direction along which the tumor recurs. Here we have established that there is a statistically significant correlation between the model predictions and the recurrence site and the average normalized cell concentration in the recurrence site is higher than the normalized cell concentration in 78% of the voxels on a surface equidistant from the primary tumor surface. Parinaz Massoumazdeh1, Xiang He1, Sarah Jost2, Keith Rich3, Dmitriy Yablonskiy1, Tammie Benzinger4 1Mallinckrodt Institute of Radiology, Washington University in Saint Louis; 2Swedish Hospital, Seattle, WA, United States; 3Neurosurgery, Washington University in Saint Louis; 4Mallinckrodt Institute of Radiology, Washington University in Saint Louis, St. Louis, MO, United States There is growing evidence that solid organ tumors with ability to grow in hypoxic conditions demonstrate resistance to conventional chemotherapy and radiation therapy. Here, we used MR qBOLD technique to measure the OEF of metastatic brain tumors before and after SRS. In this population, OEF of both the tumors and peritumoral edema prior to SRS was elevated. Following SRS, OEF decreased in the areas of lesions. This suggests that qBOLD OEF may provide a new method to monitor brain tumor response to therapy. 2185. A Comparison of Signal Intensity & DCE-MRI Based Methods for Assessing Enhancing Fraction Samantha Jane Mills1,2, Gerard Thompson1, Giovanni Buonacorrsi1, Geoff James Parker1, Alan Jackson1,2 1Imaging Science and Biomedical Engineering, University of Manchester, Manchester, United Kingdom; 2Department of Neuroradiology, Salford Royal Foundation Trust Hospital, Salford, Greater Manchester, United Kingdom The established technique for measuring Enhancing Fraction utilises the initial area under the concentration curve derived from a DCE-MRI acquisition. This can be time consuming and requires complex post processing analysis. This study examines the feasibility of obtaining an measure of Enhancing Fraction from conventional, pre and post contrast T1weighted imaging and compares this to the established DCE-MRI derived technique. The two methods show good correlation but are not directly interchangeable methods of measuring Enhancing Fraction. 2186. Simultaneous Resting State FMRI and FET-PET Irene Neuner1,2, Joachim Bernhard Maria Kaffanke1, Cornelius Werner1,2, Martina Reske1,3, Karl-Joseph Langen1, Hans Herzog1, N. Jon Shah1,2 1Institute of Neurosciences and Medicine 4, Medical Imaging Physics, Forschungszentrum Jülich GmbH, 52425 Juelich, Germany; 2Faculty of Medicine, Department of Neurology, RWTH Aachen University, 52074 Aachen, Germany; 3Department of Psychiatry, University of California San Diego, San Diego, CA, United States For the planning of surgical intervention in human brain tumour cases, it is important to know if critical brain areas might be affected by the surgical process itself. PET imaging using radiolabelled amino acids is a valuable technique for the diagnosis of cerebral gliomas. O-(2-[18F]Fluorethyl)-L-Tyrosin (FET) is a well established amino acid tracer that delivers information about tumour extent, the optimal biopsy site and detection of tumour recurrences. In this study, FET-PET and BOLD-fMRI data were acquired simultaneously; data from a representative human brain tumour case are presented. In contrast to task-based functional studies, resting state fMRI offers the opportunity to detect a variety of cortical networks in a single experiment. Ping-Hong Lai1,2, Hing-Chiu Chang3,4, Hsiao-Wen Chung4 1Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan; 2School of Medicine, National Yang-Ming University, Taipei, Taiwan; 3Applied Science Laboratory, GE Healthcare Taiwan, Taipei, Taiwan; 4Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan SWI is a novel MR technique that exploits the magnetic susceptibility differences of various tissues, such as venous structure and iron deposition. When SWI was applied to patients with abscess, we found that, compared with homogeneous rim-enhancement on post-contrast magnitude images, the capsular portion of pyogenic brain abscess on post-contrast SWI images showed a multi-layer appearance. In this work, in order to clarify whether this multi-layer characteristic is physiological or technical in it origin, we investigate the causes of this multi-layer appearance, and use a theoretical model to simulate the multi-layer appearance upon the use of different SWI processing parameters. Dee H. Wu1, Jesse Hatfield1, Jignesh Modi1, Genu Mathew1 1Radiological Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States The aim of stereotactic radiosurgery is to provide accurate placement of radiation localized to targeted diseased tissues while minimizing placement of large doses of radiation into sensitive normal tissues (such as motor strip, brain stem, internal capsule, optic nerve, and other major nerve bundles). It is well known that the brain moves during the cardiac cycle in which the action of pulsatile blood flow produces brain expansion and contraction. Such movement provides a potential conflict with the objective of providing millimeter to submillimeter localization accuracy of radiation treatment. This has led to recommendations for the use of electronic gating of radiosurgery placement. While brain motion was extensively studied in the early 1990s(1, 2), and has been a source of debate for more recent studies for the degree of head fixation required for patients for presurgical planning with fMRI (3). Such brain motion has been cited to be on the order of 0.5 mm for controlled studies over a short period of time (minutes), to 1-3 millimeters over the course of an fMRI experiment when standard to minimal head fixation is used (4). None of these studies were performed with such stringent fixation as that provided during radiotherapy. The frames such that include head fixation with the insertion of metal pins attached to the patient skull with metallic frames. Leland S. Hu1,2, Leslie C. Baxter3, Dilini S. Pinnaduwage4, Todd Jensen5, Amylou C. Dueck6, Jennifer M. Eschbacher7, Joseph E. Heiserman2, John P. Karis2, Josef Debbins3, Jonathan Placencia Placencia8, Seban Liu3, Burt G. Feuerstein9, Kathleen M. Schmainda10 1Radiology, Mayo Clinic, Arizona, Scottsdale, AZ, United States; 2Radiology, Neuroradiology Section, St. Joseph's Hospital - Barrow Neurological Institute, Phoenix, AZ, United States; 3Keller Center for Imaging Innovation, St. Joseph's Hospital - Barrow Neurological Institute, Phoenix, AZ, United States; 4Radiation Oncology, University of California - San Francisco, San Francisco, CA, United States; 5Imaging Biometrics, LLC; 6Biostatistics, Mayo Clinic, Arizona, Scottsdale, AZ, United States; 7Neuropathology, St. Joseph's Hospital - Barrow Neurological Institute, Phoenix, AZ, United States; 8Biomedical Engineering, Arizona State University, Tempe, AZ, United States; 9Neuro-Oncology, St. Joseph's Hospital - Barrow Neurological Institute, Phoenix, AZ, United States; 10Radiology, Medical College of Wisconsin, Milwaukee, WI, United States We validate mathematical modeling correction of relative cerebral blood volume (rCBV) in regards to effectiveness of 1) minimizing T1W leakage and 2) correcting T2/T2*W residual effects, by correlating localized measures with image-guided tissue histopathology and microvascular density from stereotactic biopsies in post-treatment high-grade gliomas. 2190. Automatic Segmentation of Optic Pathway Gliomas Using Multiparametric Mri Methods Liat Ben Sira1, Lior Weizman2, Leo Joskowicz2, Ronit Precel1, Shlomi Constantini3,4, Dafna Ben Bashat5 1Department of Radiology , Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel; 2School of Eng and Computer Science, The Hebrew Univeristy of Jerusalem, Jerusalem, Israel; 3The Paediatric Neurosurgery Department, Tel Aviv Sourasky Medical Center, Tel-Aviv, Israel; 4Sackler Faculty of Medicine, Tel Aviv University, Tel-Aviv, Israel; 5The Wohl Institute for Advanced Imaging, Brain Imaging Center, Tel Aviv Sourasky Medical Center , Tel-Aviv, Israel Accurate and consistent volumetric measurements of optic pathway gliomas (OPG), the most common tumor in the brain in patients with Neurofibromatosis, are clinically crucial. In this study we present an automatic method for segmentation of OPGs from multi-spectral MRI datasets. The method effectively incorporates prior location of the OPG, its shape and intensity and accurately identifies the boundaries in a consistent and repeatable manner. The method was tested on 15 data sets, the optimal threshold was derived from a receiver operating characteristic curve, and a significant correlation was obtained between the volume calculated using this method compared to manual measurements. 2191. Translational Methods for Retrospective Long Term Evaluation of Cancer with MRS Dee H. Wu1, Levi Garrett1, Jignesh Modi1, Bowei Han1, Hans Cao1 1Radiological Center, University of Oklahoma Health Sciences Center, Edmond, OK, United States We have created a procedure for retrospective review of digitized MRS images that permits fundamental baseline removal and frequency bracketing with the target of creating a user-friendly tool. This newly created clinical workflow will improve long term care for patients that may require important decisions pertaining to whether the status of a tumor has changed (such as tumor reoccurrence or remission). A central concept is that we have also conducted tolerance testing in which common confounds to artifacts that arise from shimming, electronic noise, field inhomogenity, coil sensitivities, relaxation. 2192. MR Biomarkers of Tyrosine Kinase Inhibition in Mouse Gliomas Paul A. Schornack1, Jia-Jean Yiin, Bo Hu, Raghvendra S. Sengar, Ken-Wei Liu, Haizhong Feng, Frank S. Lieberman, Jann N. Sarkaria2, Erik Wiener, Hsin-I Ma3, Shi-yuan Cheng 1Radiology, University of Pittsburgh, Pittsburgh, PA, United States; 2Mayo Clinic; 3Taiwan National Defense Medical Center We present a comparison of MR techniques sensitive to T2, T2*, & ADC to measure mouse gliomas & correlate with histology. We compare untreated mice with mice treated with an anti-angiogenic agent, ZD6474 (Zactima, vandetanib), a dual inhibitor of VEGFR2 & EG. ZD6474 significantly inhibited growth & angiogenesis of gliomas expressing EGFRvIII by specifically blocking signaling transducers in brain, which suggests a potential application in treatments for gliomas that overexpress this factor. Our results indicate that susceptibility/T2* weighted MR along with ADC and T2 measurements can be used as a means of non-invasively quantifying the efficacy of such treatment protocols. 2193. Characterization of Brain Tumor Using High Order Diffusion Imaging Chu-Yu Lee1, Chris Goettl2, Leslie C. Baxter3, John P. Karis3, Josef P. Debbins, 1,3 1Electrical Engineering, Arizona State University, Tempe, AZ, United States; 2College of Medicine, University of Arizona, Phoenix; 3Barrow Neurological Institute, Phoenix Brain neoplasms are typically characterized by contrast enhanced T1 imaging. Depending on the course of treatment, tumor reoccurrence remains a possibility, and can be difficult to distinguish from other enhancing areas, for example post-treatment radiation effects (PTRE), typically necrosis [1]. Further, detailed information about the tumor heterogeneity as detected by standard MR methods is not generally available, but can play a significant role in characterizing and grading the tumor. In this work, a simple multi-b-value DWI sequence has been developed to better understand the heterogeneity and diffusion characteristics of different types of tumors, encountered during routine clinical scanning. The signal decay is fitted with two recently developed diffusion models: a stretched exponential (£\-DWI) [2] and a cumulant expansion (DKI) [3] model, where fitted parameters £\ and Kapp were shown to correlate the diffusion heterogeneity. We expected to see differences in alpha and K when the multi-b-value DWI sequence directed to the anatomy of interest, primarily due the heterogeneity of the more advanced tumors. Ulrike I. Attenberger1, Val M. Runge2, Jonathan Williams3, Henrik J. Michaely 1Department of Clinical Radiology and Nuclear Medicine, University Medical Center Manheim, Germany, Mannheim, Baden-Württemberg, Germany; 2Scott & White Clinic and Hospital, Texas A&M University Health Science Center, Department of Radiology , Temple, TX, United States; 3Department of Radiology, , Scott & White Clinic and Hospital, Texas A&M University Health Science Center, Temple, TX, United States Regarding nephrogenic systemic fibrosis (NSF), the injected dose level becomes very important, since NSF is reported to be related to gadolinium chelate injection in patients with an impaired renal function, depending upon chelate stability and dose. With gadobenate dimeglumine, a chelate with transient protein binding and a higher r1 relaxivity became available. Combining a high relaxivity chelate and 3 T offers multiple opportunities for dose reduction without loss in image quality. This was proven in a rat brain glioma model at 1.5 and 3 T, comparing half dose gadobenate dimeglumine vs full dose gadopentetate dimeglumine, a standard extracellular gadolinium chelate.
2195. MRI Acceptance Protocol for the Multicenter GO Glioblastoma Project Sylvain Ollivro1,2, Pierre Antoine Eliat3, Eric Hitti, 2,3, Loan Tran1, Jacques Donald de Certaines1,4, Hervé Saint-Jalmes2,4 1Cancéropōle Grand Ouest, Rennes, France; 2LTSI, INSERM, U642, Université Rennes 1, Rennes, France; 3PRISM, IFR 140/Biogenouest, Université Rennes 1, Rennes, France; 4CRLCC, Rennes, France We have verified thanks to a specific common quality control that 7 MRI devices included in a multicenter clinical project, had homogenous and acceptable characteristics to allow quantification and comparison between parameters extracted from different patient images acquired on different sites and to permit correlation with biopsies. This quality control was established with sequences from the MRI protocol. The studied parameters slightly varied depending on the different sites and MRI manufacturers and were in the awaiting of the project. This kind of quality control procedure should be included at the early beginning of any multicenter clinical projects involving quantitative MRI.
2196. Large Scale Comparison of Gadobenate Dimeglumine and Comparator Agents Matthew J. Kuhn1, Howard A. Rowley2, Michael V. Knopp3, Kenneth R. Maravilla4, Zoran Rumboldt5 1Radiology, University of Illinois at Peoria, Peoria, IL, United States; 2Radiology, University of Wisconsin, Madison, WI, United States; 3Radiology, Ohio State University, Columbus, OH, United States; 4Radiology and Surgery, University of Washington, Seattle, WA, United States; 5Radiology, Medical University of South Carolina, Charleston, SC, United States 382 patients were randomized to receive 2 MR exams within 2 days to 2 weeks with equal 0.1mmo/kg doses of either gadobenate dimeglumine (N=382) or a comparator gadolinium agent. Blinded experts assessed post-contrast images for both qualitative (eg, global contrast enhancement, lesion-to-brain contrast, lesion delineation, internal lesion morphology and structure, tumor vascularization, and global image preference) and quantitative (eg, contrast-to-noise ratio [CNR]; percent lesion enhancement) efficacy parameters. In all six studies, images produced following administration of Gd-BOPTA demonstrated greater contrast enhancement, provided more diagnostic information including additional lesion detection, and were significantly preferred by experienced, blinded neuroradiologists. Brain Tumor Imaging: Diffusion, MRS & High-Field Imaging Hall B Wednesday 13:30-15:30 Peter Sherman LaViolette1,2, Benjamin M. Ellingson, 2,3, Jennifer M. Connelly, 2,4, Mark G. Malkin, 2,4, Scott D. Rand, 2,3, Kathleen M. Schmainda1,2 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 2Translational Brain Tumor Program, Medical College of Wisconsin, Milwaukee, WI, United States; 3Radiology, Medical College of Wisconsin, Milwaukee, WI, United States; 4Neurology, Medical College of Wisconsin, Milwaukee, WI, United States Traditionally, brain tumor recurrence is defined as new MRI contrast enhancement apparent in follow-up imaging. This study shows that diffusion weighted MRI edge characteristics of contrast enhancing tumors show measurable differences indicative of tumor invasion prior to contrast enhancing recurrence Peter Raab1,2, Elke Hattingen2, Kea Franz3, Friedhelm E. Zanella2, Heinrich Lanfermann1,2 1Neuroradiology, Hannover Medical School, Hannover, Germany; 2Neuroradiology, JW Goethe University, Frankfurt/Main, Germany; 3Neurosurgery, JW Goethe University, Frankfurt/Main, Germany Diffusion kurtosis imaging evaluates the non-Gaussian diffusion pattern of water and indicates tissue structure complexity. In this diffusion study we found differences between glioblastomas and cerebral metastases, that indicate more directed diffusion in glioblastomas and a higher structural complexity in metastases. Andreas Stadlbauer1,2, Michael Buchfelder2, Oliver Ganslandt2 1MR Physics Group, Department of Radiology, Landesklinikum St. Poelten, St. Poelten, Austria; 2Department of Neurosurgery, University of Erlangen-Nuremberg, Erlangen, Germany To histopathological evaluate fiber density mapping (FDM) in glioma patients for assessment of the extent of destruction of white matter structures in the center, the transition zone and the border zone of gliomas. We correlated FDM-data and histopathological findings from 78 stereotactic biopsies of 20 glioma patients. We found a negative logarithmic correlation of fiber-density with both, % tumor infiltration and tumor cell number. For a tumor infiltration of >60% no fibers are remaining. In tumor regions with <16% tumor cells functional important fiber structures may still exists. Our histopathology-fiber-density-model may be helpful for preoperative-planning to prevent post-therapeutic neurologic deficits. Benjamin M. Ellingson1,2, Mark G. Malkin1,3, Scott D. Rand1,2, Jennifer M. Connelly1,4, Pete S. LaViolette1,5, Devyani P. Bedekar1,2, Kathleen M. Schmainda1,2 1Translational Brain Tumor Program, Medical College of Wisconsin, Milwaukee, WI, United States; 2Dept. of Radiology, Medical College of Wisconsin, Milwaukee, WI, United States; 3Dept. of Neurology and Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States; 4Dept. of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States; 5Dept. of Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States Diffusion weighted imaging (DWI) measures of apparent diffusion coefficient (ADC) is believed to reflect the level of tumor cellularity in malignant gliomas. Functional diffusion maps (fDMs) were developed to examine voxel-wise changes in ADC, then stratify voxels as either increasing ADC (indicative of necrosis or "hypocellularity"), decreasing ADC (indicative of growing tumor or "hypercellularity"), or not changing within regions of contrast-enhancement or FLAIR signal abnormality. Because the particular threshold used for voxel classification dictates the sensitivity and specificity to changes in tumor cell density, we hypothesize that a graded fDM technique that stratifies voxels into varying degrees of change, applied to the whole brain, may be useful for visualizing invading and proliferating tumor with both high sensitivity and specificity. In the current study we examine graded fDMs in 120 patients and discuss how graded fDMs can be used to detect and monitor brain tumor growth and invasion beyond the traditional malignant boundary. Timothy Lloyd Jones1, Ai Wern Chung2, Andrew John Lawrence2, B Anthony Bell1, Thomas Richard Barrick2 1Academic Neurosurgery Unit, St George's University of London, London, United Kingdom; 2Centre for Clinical Neurosciences, St George's University of London, London, United Kingdom Difficulties can arise in clinical practice in differentiating between primary malignant glioma and brain metastasis owing to their similar appearances on conventional MRI sequences. Although previous studies have identified differences in diffusion parameters between the tumour types, the diagnostic role of diffusion tensor imaging (DTI) has yet to be fully elucidated. We propose an application of a novel whole brain DTI segmentation algorithm in generating regions of interest (tumour and oedema) from Diffusion Colour Maps (DCMs) created using our technique. We identify differences in diffusion between tumour types, compare our method with conventional manually drawn regions of interest and propose potential clinical applications for our method. Laleh Jalilian1, Emma Essock-Burns1,2, Susan M. Chang3, Soonmee Cha3,4, Sarah J. Nelson, 1,4 1Surbeck Laboratory of Advanced Imaging, Department of Radiology, University of California, San Francisco, San Francisco, CA, United States; 2UCSF/UCB Graduate Group in Bioengineering, University of California, San Francisco, San Francisco, CA, United States; 3Department of Neurological Surgery, University of California, San Francisco, University of California, San Francisco, San Francisco, CA, United States; 4Department of Radiology, University of California, San Francisco, University of California, San Francisco, San Francisco, CA, United States Diffusion-weighted Imaging (DWI) is an important adjunct to standard imaging in the management of GBM patients receiving anti-angiogenic treatments. In this study, ADC values were obtained for a) areas on preprogression scans that ultimately progressed to new contrast-enhancement on progression scans (NEW_CEL), and b) new FLAIR abnormality on preprogression scans with exclusion of areas of contrast enhancement and areas that progress to new contrast-enhancement on progression scans (T2ALL_M). Results demonstrated increasing ADC values in NEW_CEL but no change in T2ALL_M in scans prior to progression. Clinical implications include interpreting new FLAIR abnormality as a consequence of anti-angiogenic treatment alone. Adam Elkhaled1, llewellyn Jalbert1, Hikari Yoshihara1, Gaby Bourne1, Colleen Cloyd1,2, Joanna Phillips3, Soonmee Cha1, Susan M. Chang4, John Kurhanewicz1,5, Radhika Srinivasan1, Sarah J. Nelson1,5 1Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2School of Pharmacy, University of California, San Francisco, United States; 3Department of Pathology, University of California, San Francisco, San Francisco, CA, United States; 4Department of Neurological Surgery, University of California, San Francisco; 5Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, United States
Characterization of glioma recurrence and grade transformation has remained elusive. Image-guided biopsies from glioma patients were evaluated using pathology, in-vivo ADC, and ex-vivo proton HR-MAS spectroscopy. Newly diagnosed and recurrent grade IV tissue samples were found indistinguishable from one another. A comparison of recurrent grade IV to recurrent low-grade glioma revealed a significant difference in [myo-inositol] and [creatine]; recurrent low-grades which had upgraded displayed higher total choline compared to non-upgraded and high-grade glioma; the [myo-I]/[total choline] ratio differentiated non-upgraded low-grades from all other cohorts. ADC values demonstrated an inverse relationship with tumor grade and negative correlation with glutathione.
Ilwoo Park1,2, Adam Elkhaled2, Achuta Kadambi2, Inas Khayal2, Nicholas Butowski3, Susan M. Chang3, Sarah J. Nelson1,2 1Joint Graduate group in Bioengineering, University of California San Francisco/Berkeley, San Francisco, CA, United States; 2Surbeck Laboratory of Advanced Imaging, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States; 3Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, United States The purpose of this study was to use 3D 1H MR Spectroscopic Imaging (MRSI) and diffusion tensor imaging (DTI) to develop early prognostic markers for GBM patients undergoing radiation, temozolomide and PKC inhibitor. Twenty-nine patients with newly diagnosed GBM were examined using a 3T MR scanner. Conventional anatomical imaging parameters could not distinguish between progression groups at baseline or 1 month. Parameters derived from MRSI and DTI provided information at baseline and early follow-up examinations that may be valuable in predicting the time-to-progression for patients with GBM. 2205. Longitudinal MRSI Study in Newly Diagnosed Glioblastoma Multiforme Yan Li1, Janine M. Lupo1, Soonmee Cha1, Susan Chang2, Sarah J. Nelson1,3 1Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States; 2Department of Neurological Surgery, University of California, San Francisco, CA, United States; 3Department of Bioengineering & Therapeutic Sciences, University of California, San Francisco, CA, United States Glioblastoma Multiforme (GBM) is the most common and malignant type of primary brain tumor, resulting in a median survival of approximately one year. Our study of 18 patients with GBM indicated that metabolic abnormalities more accurately reflect the underlying tumor burden. We found that the Cho to NAA index (CNI) values in the contrast-enhancing lesion (CEL) are elevated at 2 months prior to progression while having less changes in CEL volume at that time. Patients who have a CEL volume with high CNI values are more likely to progress compared with those who have with smaller CEL volume and lower CNI values. We also observed that the regions with high CNI values outside the CEL region could subsequently become enhancing. 2206. 31P and 1H Spectroscopic Imaging of Recurrent Malignant Gliomas Ulrich Pilatus1, Joerg Magerkurth1, Oliver Bähr2, Joachim Steinbach2, Elke Hattingen1 1Institute of Neuroradiology, University Hospital, Goethe-University, Frankfurt, Germany; 2Senckenbergisches Institute of Neurooncology, University Hospital, Goethe University Proton and 31P MRSI was performed on human malignant recurrent gliomas in order to provide in vivo analysis of membrane metabolism and neuronal brain damage (tNAA). Phosphorylated components in the membrane metabolism showed clear changes indicating a shift to proliferating cell fractions. While the increase in the phosphocholine/glycerophosphocholine ratio in tumor tissue did not reach significance (p=0.07) the respective ratio for the ethanolamine compound was clearly significant (p=0.02). Further, the significant increase in the inorganic-phosphate/phosphocreatine ratio hints to limited energy supply within the tumor. 2207. Comparison of in Vivo MRS Glutamate/Glutamine Levels in Tumor-Associated Epilepsy Christopher Steward1, Bradford Moffat1, Tanya Yuen2, Terence O'Brien2, Patricia Desmond1, Andrew Morokoff3, Chris Kokkinos4 1Radiology, University of Melbourne, Melbourne, VIC, Australia; 2Medicine, University of Melbourne, Melbourne, VIC, Australia; 3Surgery, University of Melbourne, Melbourne, VIC, Australia; 4Radiology, Royal Melbourne Hospital, Melbourne, VIC, Australia The pathogenesis of tumour associated seizures (TAS), a common co-morbidity with brain tumors remains poorly understood. Glutomate has been implicated in many types of epilepsy. In a pilot study the concentration of glutamate/glutamine associated with gliomas using in vivo MRS was studied, and correlated with observed pre-operative seizures. Elevated glutamate/glutamine levels were found in the peritumoral area of tumours who experienced pre-operative seizures compared to those which did not. Due to the small sample size, we are in the process of acquiring a larger MRS and ex vivo prospective data set (N>100) to confirm these findings. Franklyn Arron Howe1, Tom R. Barrick2, Greg A. Fellows3, Alan J. Wright4 1Cardiac & Vascular Sciences , St George's, University of London, London, United Kingdom; 2Clinical Neuroscience, St George's, University of London, London, United Kingdom; 3Academic Neurosurgery, St George's, University of London, London; 4Radiology, UMC st. Radboud University Hospital, Nijmegen, Netherlands Metabolic information from 1H MRSI may aid image segmentation using DTI and so improve delineation of infiltrative brain tumours such as gliomas. NAA and fractional anisotropy (FA) are expected to decrease with tumour infiltration and loss of neuronal structure, but FA calculated from principal diffusion magnitude images is biased due to the contribution of noise. We have investigated the FA and NAA distribution in glioblastomas in comparison to simulated data that takes into account the effect of SNR on the measurement of low FA values. Our data provides evidence for diffusion anisotropy in glioblastomas in the absence of functional neurones. Jean-Marc Constans1,2, Franēois Kauffmann3, Gabriela Hossu4, Weibei Dou5, Jean-Michel Derlon6, Emmanuelle Lechapt-Zalcmann7, Samuel Valable8, Jean-Sebastien Guillamo9,10 1MR Unit, CHU de CAEN, CAEN, Normandy, France; 2CERVOxy, Cyceron- CI-NAPS- CNRS , CAEN, Normandy, France; 3LMNO- UMR 6139, CNRS, CAEN, France; 4UMR 947, CIC-IT et INSERM, Nancy, France; 5Electronic, Tsinghua University, Beijing, China; 6CHU de Caen, CAEN, France; 7CHU de Caen, Caen, France; 8Cyceron CINAPS CNRS UMR 6232, CAEN, France; 9CHU CAEN, France; 10CERVOxy, Cyceron CNRS CI-NAPS, CAEN, France MRS with Cho/Cr, mI/Cr and NAA/Cr ratios, could be more sensitive than MRI and could, in some cases, be predictive of worsening in gliomatosis follow-up. These spectroscopic changes occurred well before clinical deterioration. There is a large variability, but repetition and modelisation of spectroscopic measurements during longitudinal follow-up could allow us to diminish it and to improve gliomatosis prognostic evaluation. Studying the relationship between MRS measures, methionine PET, segmentation and perfusion parameters could lead to better understanding of therapeutic response, especially with regard to chemotherapy and antiangiogenic molecules and in the future hypoxia modulators.
2210. Prominent Citrate Predicts Malignant Progression of Low-Grade Astrocytomas in Children Arabhi C. Nagasunder1, Mikhail Laskov2, Albert Joseph2, Ashok Panigrahy1,3, Girish Dhall2, Jonathan L. Finlay2, Ignacio Gonzalez-Gomez4, Mark D. Krieger5, Marvin D. Nelson1, Stefan Bluml1,6 1Department of Radiology, Childrens Hospital Los Angeles, Los Angeles, CA, United States; 2Childrens Center for Cancer and Blood Diseases, Childrens Hospital Los Angeles, Los Angeles, CA, United States; 3Department of Radiology, Childrens Hospital of Pittsburgh of UPMC, Pittsburgh, PA, United States; 4Department of Neuropathology, Childrens Hospital Los Angeles, Los Angeles, CA, United States; 5Department of Neurosurgery, Childrens Hospital Los Angeles, Los Angeles, CA, United States; 6Rudi Schulte Research Institue, Santa Barbara, CA, United States Pediatric low-grade gliomas can either progress to a high-grade lesion or remain dormant for long periods of time. Currently, there is a need to identify markers that would allow pediatric neuro-oncologists to predict tumor progression. Our goal was to determine whether aggressive pediatric low-grade II astrocytoma have metabolic features that distinguishes them from stable grade II astrocytoma using in vivo MR Spectroscopy. We found that elevated citrate and low NAA may predict malignant progression of low-grade astrocytomas. Santosh Kumar Yadav1, Sona Saksena1, Anshu Srivastava2, Arti Srivastava1, Vivek A. Saraswat3, Michael A. Thomas4, Ram Kishore S. Rathore5, Rakesh K. Gupta1 1Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 2Pediatric gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 3Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; 4Radiological Sciences, UCLA School of Medicine, Los Angeles, CA, Los Angeles, CA, United States; 5Mathematics and Statistics, Indian Institute of technology Kanpur, Kanpur, Uttar Pradesh, India Sixty-three patients with EHPVO having different age groups with 47 age/sex matched controls were studied. Neuropsychological tests, MR imaging, 1H-MR Spectroscopy and blood-ammonia estimation were performed in all subjects. 40% EHPVO patients had MHE who showed significantly increased Mean diffusivity, Glx/Cr, blood-ammonia and GP T1 H in all age groups; however, mIns/Cr was significantly lower only in adults when compared to controls. Mean diffusivity positively correlated with blood-ammonia and Glx/Cr in all age groups. A significant positive correlation was observed between Glx/Cr and blood-ammonia. Increases in Mean diffusivity, Glx/Cr, blood-ammonia and GP T1 H and decrease in mIns/Cr are associated with pathogenesis of MHE in adults with EHPVO. No change of cho/Cr in EHPVO may serve as a diagnostic marker for its differentiation from cirrhosis induced MHE. A significant positive correlation among blood ammonia, Glx/Cr and mean diffusivity indicates that hyperammonia contributes to the generalized low grade cerebral edema. 2212. Repeatability of Measured Lactate and Other Metabolites in Patients with Astrocytoma Mary McLean1, Amy Sun2, Radha Railkar2, Andrea Schaeffer2, Thomas Bradstreet2, Haiying Liu2, Rose-ann Blenman-Abange2, Ilse Joubert3, Stephen Price3, Charlotte Hodgkin3, John Griffiths1 1Cambridge Research Institute, Cancer Research UK, Cambridge, England, United Kingdom; 2Merck & Co Inc, West Point, PA, United States; 3Addenbrooke's Hospital, Cambridge, United Kingdom We implemented lactate editing at 3T using BASING pulses and assessed its repeatability in phantoms and in human brain tumours in vivo to estimate the level of lactate and other metabolites . In phantoms, a coefficient of variation of 11% was achieved for lactate with SNR similar to in vivo. In tumours, lactate was detected, and there was a non-significant trend of lower metabolite concentrations in scan 2 than scan 1. Lactate editing may provide a useful means of simultaneously monitoring lactate, choline and lipids in vivo, all of which are of interest in tumour progression and response to treatment. Xiang Liu1, Wei Tian1, Sven Ekholm1 1Department of Imaging Science, University of Rochester Medical Center, Rochester, NY, United States Grading of non-enhancing supratentorial gliomas and neuronal-glial tumors (NEGNGT) is a diagnostic dilemma on conventional MR imaging as 45% of these tumors could be malignant. We retrospectively compared diffusion tensor imaging (DTI), MR perfusion weighted imaging (PWI) and MR spectroscopic imaging in preoperative grading of 50 patients with histology confirmed non-enhancing supratentorial gliomas and neuronal-glial tumors. The imaging parameters, included mean FA, mean FA ratio, maximal FA, minimal ADC, maximal rCBV, Cho/Cr and Cho/NAA which all were evaluated for both tumor groups. There were significant differences of mean FA, mean FA ratio and maximal FA between low and high grade NEGNGT(p<0.05), but no significance was found for the other parameters. ROC analysis showed that the maximal FA value had a higher sensitivity and specificity than the other parameters to differentiate between low and high grade NEGNGT. This result indicates that maximal FA may be the best adjuvant tool to help differentiating between low and high grade in non-enhancing supratentorial gliomas and neuronal-glial tumors. 2214. MR Biomarker Profile for Infiltrative Tumor Region in Malignant Glioma Radhika Srinivasan1, Joanna J. Phillips1, Gabriela Bourne1, Alvin Au1, Soonmee Cha1, Susan Chang1, Sarah J. Nelson1 1University of California, San Francisco, San Francisco, CA, United States This study addresses the inability of conventional imaging to delineate infiltrative tumor regions, which causes the tumor to recur within the treatment volume. These regions have normal cellularity due to diffusely infiltrating cells and cannot be located based on increased cellularity with choline and ADC. To define an MR profile of an infiltrative tumor region HR-MAS spectroscopy of image-guided biopsies in newly diagnosed and recurrent GBM were analyzed and evaluated relative their spatial location within the tumor, pathological measures of its paired sample and diffusion measures derived from the biopsy location. These results will be presented and discussed. 2215. Assessment of Vascularity in Malignant Glioma: Development of an Imaging Protocol at 7 T Lars Gerigk1, Armin Nagel2, Armin Biller1, Julien Dinkel1, Lydia Schuster1, Thomas Hauser1, Michael Puderbach1, Marco Essig1, Stefan Delorme1, Michael Bock2 1Radiology, German Cancer Research Institute, Heidelberg, Baden-Württemberg, Germany; 2Medical Physics in Radiology, German Cancer Research Institute, Heidelberg, Baden-Württemberg, Germany Malignant gliomas are highly vascularized, which makes them a target for new anti-angiogenic agents. MRI therapy monitoring will require more sophisticated methods than measuring the extent of contrast enhancement, because these agents change the blood-brain-barrier. Using the advantage of 7 T, direct imaging of the tumor vasculature becomes feasible. In our newly developed clinical imaging protocol, high-resolution T2w and T1w images show the internal morphology of the lesion, whereas TOF-MRA and SWI visualize the arterial and venous intratumoral vasculature. Automatic co-registration of MRA and morphology proved to be a simple, fast and reliable method to evaluate tumor vascularization. 2216. Initial Experience with Ferumoxytol Dynamic Susceptibility MRI in Human Brain at 3T and 7T Jeffrey Moses Njus1, Edit Dosa2, Seymur Gahramanov2, John W. Grinstead3, Xin Li1, Charles S. Springer, Jr. 1, Edward A. Neuwelt2, William D. Rooney1 1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States; 2Department of Neurology, Oregon Health & Science University, Portland, OR, United States; 3Siemens Medical Solutions, Portland, OR, United States MRI DSC techniques offer an efficient way to characterize brain perfusion properties. However, the use of low-molecular weight gadolinium based contrast agents (Gd) can introduce a significant confound into standard DSC analysis if extravasation is extensive; as often is the case for brain tumors. The purpose of this study was to investigate the use of an ultra-small paramagnetic iron oxide (USPIO) compound to estimate brain tumor blood volume in human subjects. To accomplish this goal, DSC acquisitions were performed using both Gd and USPIO based contrast agents in eleven human subjects at 3T and 7T. Clinical Stroke Imaging: DWI DKI, MTC MRS & Plaque Imaging Hall B Thursday 13:30-15:30 2217. Identification of Early Onset Strokes Using Multiparametric MRI as a Witness Ona Wu1, Lee H. Schwamm2, Priya Garg1, Muhammed A. Pervez2, Albert J. Yoo3, Aurauma Chutinet2, Robert Irie1, Byeongseo Yook1, William A. Copen3, Pamela W. Schaefer3, Aneesh B. Singhal2, Karen L. Furie2, Alma Gregory Sorensen1 1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States; 2Department of Neurology, Massachusetts General Hospital; 3Department of Radiology, Massachusetts General Hospital Approximately 25% of ischemic stroke patients have unwitnessed strokes and therefore ineligible for on label thrombolytic therapy. We investigated whether multiparametric MRI can be used for identifying patients who have early stage strokes (<=4.5 h). Acute DWI, PWI and FLAIR images from acute stroke patients imaged within 12 h since last known to be well (N=175) were analyzed. In regions that were DWI abnormal, there were significant difference in relative T2WI and FLAIR between patients seen within 4.5 h and those seen later. Multivariate logistic regression showed that T2WI, ADC, and CBV were predictive of patients with early onsets. 2218. Evolution of Fractional Anisotropy in Hyperacute Ischemic Stroke Ashley D. Harris1,2, Linda B. Andersen, 2,3, Robert K. Kosior, 2,4, Henry Chen, 2,5, Marina Salluzzi, 2,4, Randall B. Stafford, 2,5, Bradley G. Goodyear, 2,3, Richard Frayne, 2,3 1School of Psychology, CUBRIC, Cardiff University, Cardiff, United Kingdom; 2Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, Alberta, Canada; 3Clinical Neurosciences and Radiology, Univerisity of Calgary, Calgary, Alberta, Canada; 4Biomedical Engineering, Univerisity of Calgary, Calgary, Alberta, Canada; 5Physics, Univerisity of Calgary, Calgary, Alberta, Canada Diffusion-weighted images and apparent diffusion coefficient maps are widely used in ischemic stroke detection; however, additional information may be available from diffusion imaging in the assessment of hyperacute ischemic stroke. In this study, fractional anisotropy was examined during hyperacute ischemic stroke (06h from onset) in a canine model. White matter shows a biphasic FA response; an initial increase followed by a decrease. Grey matter showed FA increases. The timing and magnitude of these FA changes appears to be related to stroke severity. With thorough understanding of these changes, FA may be useful in treatment decisions for stroke patients. Danielle van Westen1,2, Markus Nilsson3, Håkan Sjunnesson1,2, Freddy Ståhlberg, 2,3, Sara Brockstedt4, Ronnie Wirestam3, Jimmy Lätt1,3 1Center for Medical Imaging and Physiology, Lund University Hospital, Lund, Sweden; 2Department of Diagnostic Radiology, Lund University, Lund, Sweden; 3Department of Medical Radiation Physics, Lund University, Lund, Sweden; 4Radiation Physics, Lund University Hospital, Lund, Sweden Diffusion measurements were performed 2, 9 and 90 days after stroke onset, estimating the mean diffusivity (MD), the apparent diffusion kurtosis (ADK) and the fractional anisotropy (FA). Tissue outcome at day 90 was dependent on tissue type, i.e. white- or grey matter, as well as location. For instance, deep white matter developed gliosis, while subcortical U-fibres pseudonormalized. FA and ADK obtained at day 2 predicted the tissue outcome at day 90 in white matter. N Jane Taylor1, Vicky J. Goh1, J James Stirling1, Ian Simcock1, Matthew Orton2, David J. Collins2, Ralph Strecker3, Leon Menezes4, Raymond Endozo4, Justin J. Cross5, Richard Harvey6, Carl W. Kotze6, Syed W. Yusuf6, Ashley Groves4 1Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, United Kingdom; 2CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research & Royal Marsden Hospital, Sutton, Surrey, SM2 5PT, United Kingdom; 3Healthcare Sector, Siemens AG, 91052 Erlangen, Germany; 4University College Hospital, London, United Kingdom; 5Addenbrookes Hospital, Cambridge, United Kingdom; 6Brighton and Sussex University Hospitals, Brighton, Sussex, United Kingdom Accurate identification of vulnerable carotid plaque influences patient treatment. Diffusion weighted imaging at 3T may potentially contribute to the identification of active plaques. This feasibility study in 14 patients with symptomatic disease assesses the correlation between plaque apparent diffusion coefficient (ADC) and imaging/histopathological features of vulnerability (thin cap, lipid core, haemorrhage, angiogenesis (CD105 or VEGF) & inflammation (CD68). Mean (SD) plaque ADC was 1.30 X10-3(0.29) mm2/s. There was no difference in ADC between patients with and without MRI features of plaque vulnerability. There was a positive trend between ADC & CD105/VEGF, markers of angiogenesis meriting further investigation. Mohamed Mustafa Hirji1,2, Ashley D. Harris, 2,3, Robert K. Kosior, 2,4, Cheryl R. McCreary, 2,5, Richard Frayne2,5 1University of Calgary, Calgary, Alberta, Canada; 2Seaman Family MR Research Centre, Alberta Health Services, Calgary, Alberta, Canada; 3School of Psychology & Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, Wales, United Kingdom; 4Biomedical Engineering, University of Calgary, Calgary, Alberta, Canada; 5Radiology & Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada We characterise the fractional anisotropy (FA) changes in ischemic stroke. Diffusion tensor images of 13 patients were obtained within 26 hours of stroke (acutely) and >21 days later (follow-up). FA and eigenvalues were measured in freehand regions of interest (ROIs); anatomically-matched contralateral ROIs were used for control. Acutely, FA increased in gray matter (GM) but not in white matter (WM); the eigenvalue reductions were unbalanced in GM, but balanced in WM. At follow-up, FA decreased in both GM and WM with the eigenvalue changes similar in both GM and WM. Our results give insight into microstructural changes in stroke. Jiabao He1, Dinesh Tryambake1, Michael J. Firbank2, John T. OBrien2, Gary A. Ford1, Andrew M. Blamire1 1Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom; 2Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom CBF determines brain tissue metabolic supply and is compromised in chronic hypertension which alters autoregulatory function. Blood pressure (BP) lowering therapy has clear clinical benefit but may risk inducing hypoperfusion. Optimal target BP in older subjects with hypertension is unclear, although guidelines recommend target BP of <130/85 mmHg and <140/80 mmHg for patients with and without previous vascular events respectively. We used ASL to determine the effect of usual (<140/85 mmHg) and intensive (<130/80 mmHg) BP lowering on CBF in older hypertensive subjects and demonstrate that intensive BP lowering increases CBF compared to usual BP lowering therapy. 2223. Correlation Study of Cerebral Blood Flow and EEG Feature Based on CO2 Stimulation Jing Wang1, Liu Chen1, Bing Wu2, Xiaoping Hu3, Xiaoying Wang, 12, Jue Zhang1,4, Jing Fang1,4 1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; 2Dept. of Radiology, Peking University First Hospital, Beijing, China; 3Dept. of Biomedical Engineering, Georgia Institute of Technology / Emory University, Atlanta, United States; 4College of Engineering, Peking University, Beijing, China The MR based evaluation of cerebral blood flow (CBF) plays an important role in assessment of post-stroke rehabilitation, but limits by its inconvenient and high costs. In this study, the weighted average accuracy index (WAAI), as a novel electroencephalogram (EEG) feature related index was introduced to estimate effectively the change of EEG pattern with the gradual CBF improvement due to the increase of CO2 concentration. Group results of healthy subjects showed that there existed a strong relationship between WAAI and CBF, indicating that the proposed WAAI index could be helpful to evaluate the extent of brain perfusion recovery. 2224. MRI Study of ASL, MRS and BOLD in Patients with Left Symptomatic Internal Carotid Artery Jie Lu1, KunCheng Li1, Miao Zhang, XiaoYi Wang 1Xuanwu Hospital, Capital Medical University, Beijing, China Arterial Spin Labeling (ASL) can quantitatively measure perfusion without the need of contrast material. 1H spectroscopy (1H-MRS) can identify cerebral abnormal metabolism. Patients with symptomatic occlusion of the internal carotid artery (ICA) with compromised cerebral blood flow (CBF) and decrease N-acetyl aspartate (NAA) are at risk for future ischemic infarcts. These patients can have different degree of cognitive impairment, especially working memory impairment2. Blood oxygenation level dependent (BOLD) is best used for studying processes that can be rapidly turned on and off like memory. In this study, we characterized CBF, MRS and BOLD changes in patients with symptomatic ICA occlusion.
Urska Puh1, Andrej Vovk2, Igor Sera3, Dusan Suput4 1University of Ljubljana, Faculty of Health Sciences, Ljubljana, Slovenia; 2Pathophysiology, Univ. of Ljubljana Faculty of Medicine, Ljubljana, Slovenia; 3Institut Jozef Stefan, Slovenia; 4Pathophysiology, Univ. of Ljubljana Faculty of Medicine, Slovenia 12 patients with partially impaired function of one upper extremity 2-8 days after first ischemic stroke participated in the study. A 1.5 T scanner was used for brain fMRI during upper extremity functional tasks in the first and third week and 3 months after the stroke. Muscle strength and dexterity of the HPE were measured concomitantly. Spearman correlation coefficient was calculated to compare the M1 activation of each brain hemisphere and the motor characteristics of the HPE. Recovery of HPE function correlated well with the intensity and/or area of M1 cortex activation mainly in the ipsilesional hemisphere.
Wan Chun Kuan1, Ting Yu Chang2, Keh Shih Chuang1, Ho Fai Wong3, Tsong Hai Lee2, Ho Ling Liu4,5 1Dept. of Biomedical Engineering and Environmental Sciences, National Tsing Hua Univ., Hsinchu, Taiwan; 2Stroke Center, Department of Neurology, Chang Gung Memorial Hospital; 3Department of Neuroradiology, Chang Gung Memorial Hospital; 4Dept. of Medical Imaging and Radiological Sciences, Chang Gung Univ.; 5Dept. of Medical Imaging and Intervention, Chang Gung Memorial Hospital Impaired cerebral vasoreactivity could be one of the predictors for hyperperfusion after carotid interventions for patients with internal carotid artery (ICA) stenosis. This study aimed to evaluate the differences of hemodynamic responses among blood-supply territories, induced by vasodilatation following a breath-holding task, in patients with unilateral ICA stenosis using BOLD MRI. The temporal correlation between bilateral vasomotor responses in the MCA territories was utilized as an index. The results showed significantly impaired responses of the lesion side as compared to the normal side (p<0.05) for patients exhibited hyperperfusion after the stenting (sensitivity = 100%, specificity = 92.3%). Felix Jax1, Monika Gloor2, Oliver Bieri2, Meritxell Garcia1, Stefan Engelter3, Felix Fluri3, Klaus Scheffler2, E.-W. Radue1, SG Wetzel1 1Department of Neuroradiology, University of Basel Hospital, Basel, Switzerland; 2Department of Radiological Physics, University of Basel Hospital, Basel, Switzerland; 3Department of Neurology, University of Basel Hospital, Basel, Switzerland Magnetisation transfer (MT) imaging can potentially serve as a marker for loss of tissue integrity. Moreover increased pathologic specificity is expected from quantitative MT (qMT) as compared to the assessment of the semi-quantitative MT ratio (MTR) images only. Here, we present an evaluation of qMTI data over three consecutive MRIs within the first 10 days for patients suffering from middle cerebral artery stroke with different progression of symptoms. Results seem to be superior to simple MTR measurements and possibly allow for early statement of prognosis and efficacy of therapeutic methods. 2228. The Assessment of Vessel Size Index and Its Application in Patients with Ischemic Stroke Chao Xu1, Wolf Schmidt1, Peter Brunecker1, Valerij Kiselev2, Peter Gall2, Nils Bodammer3, Jochen Fiebach1 1Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Berlin, Germany; 2Medical Physics, Department of Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany; 3Max Planck Institute for Human Development, Berlin, Germany This study aims at implementation and evaluation of vessel size imaging (VSI) in patients with ischemic stroke. Stable values of vessel diameter have been observed in healthy volunteers in a good agreement with anatomic knowledge. VSI measurement is shown to be feasible for the clinical examination in stroke patients. Given the limitations of small number of patients, hypointensities on VSI maps in acute and chronic stage have been observed in areas of the final infarction. The recovered tissue showed normal VSI in the acute phase. Naoki Ohno1,2, Tosiaki Miyati2, Mitsuhito Mase3, Hirohito Kan2, Harumasa Kasai4, Masaki Hara4, Yuta Shibamoto4, Kazuo Yamada3, Akihiro Kitanaka2, Tomoyuki Yamamoto1 1Department of Radiological Technology, Kanazawa University Hospital, Kanazawa, Japan; 2Faculty of Health Sciences, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, Japan; 3Department of Neurosurgery and Restorative Neuroscience, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan; 4Department of Radiology, Nagoya City University Hospital, Nagoya, Japan There have been many unsolved problems with this syndrome in terms of the diagnostic criteria and selection of appropriate patients for shunt surgery. To evaluate the intracranial condition of the brain in idiopathic normal-pressure hydrocephalus (I-NPH), we determined the change in the apparent diffusion coefficient of the brain during the cardiac cycle (delta-ADC). Delta-ADC analysis makes it possible to noninvasively obtain new and more detailed information on the intracranial condition in I-NPH and thereby assist in the diagnosis. Stroke: Animal Models Hall B Monday 14:00-16:00 Maurits P.A. van Meer1,2, Wim M. Otte1,3, Kajo van der Marel1, Jan W. Berkelbach van der Sprenkel2, Rick M. Dijkhuizen1 1Biomedical MR Imaging and Spectroscopy group, Image Sciences Institute, Utrecht, Netherlands; 2Department of Neurosurgery, Rudolf Magnus Institute of Neuroscience, Utrecht, Netherlands; 3Department of Neurology, Rudolf Magnus Institute of Neuroscience, Utrecht, Netherlands Reorganization of neuronal networks may effectively constitute spontaneous functional recovery after stroke. However, the association between structural and functional remodelling in post-stroke brain remains unclear. In this study we combined resting-state fMRI with manganese-enhanced MRI to elucidate the relationship between functional and structural brain connectivity in presumably reorganized contralesional brain tissue in rats that have recovered from experimental unilateral stroke. We detected increased uptake of the neuroanatomical tracer manganese in the contralesional sensorimotor cortex that was significantly correlated with enhanced functional connectivity within this region. Our data suggest that improved neuroanatomical connectivity underlies enhancement of functional connectivity in reorganizing neuronal networks after stroke. 2231. Evolution of Functional Connectivity After Transient Stroke in Rats Woo Shim1,2, Kwangyeol Yeol Baek1,2, Jeong Kon Kim3, Guangping Dai1, Jaeseong Jeong2, Bruce Rosen1, Young Ro Kim1 1Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States; 2Bio and brain engineering, KAIST, Yuseong-gu, Daejeon, Korea, Republic of; 3Radiology, Asan Medical Center, Seoul, Korea, Republic of We monitored changes of resting-states functional connectivity using cross-correlation technique over a period of 30 days after transient cerebral ischemic damage. Averaged correlation strengths among some ROIs in stroke rats monotonically increased within the contralesional hemisphere over time, eventually matching those in control group. Despite the slight recovery, cross-correlation values measured within ipsilesional hemisphere and between bilateral hemispheres show severely impaired functional connectivity over 30 days after stroke. Although highly speculative, the data demonstrated that the initial limb dysfunction is related to the loss of brain connectivity in both ipsi- and contra-lesonal brain regions and that the restoration of function may be associated more with the increase of functional connectivity within the contralesional than the ipsilesional hemisphere. 2232. Multi-Parametric Stroke Imaging Protocol for Mice Using a 1H Cryo Probe at 9.4 T Patrick Michael Heiler1, Friederike Lara Vollmar2, Melanie Heilmann1, Andreas Lemke1, Stephen Meairs2, Marc Fatar2, Lothar Rudi Schad1 1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Experimental Neurology, Heidelberg University, Mannheim, Germany The investigation of rt-PA therapy after MCAo in mice by means of MRI requires adequate resolution for the brain size of about 1 x 1 cm², in measurement times acceptable for follow-up studies. We present a protocol including t2-weighted imaging, diffusion weighted imaging and a TOF angiography using a 1H surface cryo coil at 9.4T. The results demonstrate that rt-PA therapy leads to reperfusion of the MCA and significantly reduces the extension of ischemia. The short measurement time makes the protocol suitable for both, detection of the MCAo success immediately after the surgery and temporal evolution studies after rt-PA therapy. 2233. High-Resolution 31P Chemical Shift Imaging of Acute Stroke at 11.7T Andrew Bresnen1, Fang Du1, Qiang Shen1, Geoffrey Clarke2, Timothy Q. Duong1 1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Tx, United States; 2Radiological Sciences, University of Texas Health Science Center at San Antonio, San Antonio, Tx, United States In vivo 31P chemical shift imaging allows direct measurements of the high energy phosphates. 31P NMR has proven useful for investigating the bioenergetics in normal brain. However, the low SNR, long scan time and low spatial resolution of 31P NMR have prevented its widespread use, particularly in the study of acute stroke. This study implemented and optimized 31P CSI on rat brain with high spatio-temporal resolution at 11.7T. This approach, along with 1H diffusion, perfusion and T2 MRI, was used to investigate changes of high energy phosphates in stroke rats at 1, 3 and 24 hrs after onset. Hongxia Lei1,2, Yohan Van de Looij1,3, Nicolas Kunz1,3, Carole Berthet4, Lorenz Hirt4, Rolf Gruetter1,5 1LIFMET, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 2Radiology, University of Lausanne, Lausanne, Switzerland; 3Pediatrics, University of Geneva, Geneva, Switzerland; 4Neurology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; 5Radiology, University of Geneva, Geneva, Switzerland Diffusion tensor imaging allowed accurately measuring ADC, which is very essential for stroke studies. We sought to establish feasibilities of EPI-version DTI of mouse brain after brief ischemia at 14T. The nearly artifact free DTI images allowed accurately measuring ADC maps and help localizing ischemic core more precisely when no abnormal T2 contrast expressed. Kazuhiro Nakamura1, Yasushi Kondoh1, Shigenori Mizusawa1, Junko Yoshida1, Hajime Miyata1, Toshibumi Kinoshita1 1Akita Research Institute for Brain and Blood Vessels, Akita, Japan Strong hyperperfusion was observed in transient ischemic tissue 48-72 h after middle cerebral artery occlusion (MCAO). To investigate a physiological reason for the phenomena, we have performed experiments for revealing cerebral blood flow (CBF) autoregulation in transient ischemic tissue using a lower body negative pressure method. Using the lower body negative pressure method, we can avoid an estimation error in CASL from a blood oxygen dependent signal change. The results show CBF in ischemic tissue is higher than normal in all blood pressure range and it should indicate the autoregulatory failure of small pial artery in the ischemic tissue. 2236. Incorporating ADC Temporal Profiles in Acute Stroke to Predict Ischemic Tissue Fate Virendra R. Desai1, Qiang Shen1, Timothy Q. Duong1 1Research Imaging Institute, Ophthalmology/Radiology, UT Health Science San Antonio, San Antonio, TX, United States Acute diffusion data has been used to predict ischemic tissue fate on a pixel-by-pixel basis. Previous predictions however were made based on acute MRI data from a single time point. This study proposes a novel approach to incorporate the temporal characteristics of acute ADC (apparent diffusion coefficient) changes to characterize tissue fate based on a pixel-by-pixel basis. This approach was tested on rat stroke models subjected to permanent and 60-min middle cerebral artery occlusion (MCAO). We concluded that there were distinct temporal patterns that determined tissue salvageability. Young Ro Kim1, Xiang Fan2, Guangping Dai1, Jeong Kon Kim3, Bruce R. Rosen1, xiaoying Wang2 1Radiology, Martinos Center for Biomedical Imaging / Massachusetts General Hospital, Charlestown, MA, United States; 2Radiology, Neuroprotection Research laboratory / Massachusetts General Hospital, Charlestown, MA, United States; 3Radiology, Asan Medical Center, Seoul, Korea, Republic of Tissue plasminogen activator (tPA) has been frequently used for treating acute ischemic stroke based on re-canalization, reopening of occluded vessels for the reinstitution of regional blood perfusion. Despite the promising clinical outcomes, exogenous tPA may worsen the ischemia-induced blood brain-barrier disruption, elevate risks of intracranial hemorrhage, and in part consequently reduces the therapeutic time window. Therefore, it is critically important to understand the overall effects of tPA treatment on cerebrohemodynamics. In this study, we investigated the vasoreactivity in response to intravenously administered tPA and to systemic hypercapnia before and after tPA using a permanent focal stroke rat model. Fang Du1, Shiliang Huang1, Qiang Shen1, Timothy Q. Duong1 1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States Mismatch of diffusion/perfusion by MRI has been used as an estimate of the ischemic penumbra, but there are large parts of the mismatch region appear not to at risk and it was also reported that some of the apparent diffusion coefficient reduction area can be salvaged by early reperfusion. It was proposed that T2* weight signal change of oxygen challenge could be a better penumbra estimation. This study applied OC technique to a group of transient ischemia rats and proved this hypothesis. Ronn Philip Walvick1, Bernt Torre Bratane2, James Bouley2, Nills Henninger2, Mitchell Albert1, Marc Fisher1 1Radiology, University of Massachusetts Medical School, Worcester, MA, United States; 2Neurology, University of Massachusetts Medical School, Worcester, MA, United States We present a novel technique to localize and observe the dynamics of clot lysis during tissue Plasminogen Activator (tPA). Prior to fabrication of clots, blood was doped with Magnevist (Bayer, Wayne, NJ). Clots were withdrawn tubing and injected into the left common carotid artery at the base of the skull causing a middle cerebral artery occlusion. MRI consisted of diffusion, perfusion, and T1 weighted imaging for clot localization, and MR angiography. During tPA administration, serial T1 weighted and perfusion imaging was performed. Our results demonstrate the ability of this method to detect clots in a preclinical model of embolic stroke. Denise C. Welsh1, Andrew Danziger2, Theodore Detwiler2, Hillary Regan2, Joseph J. Lynch2, Christopher P. Regan2, Donald S. Williams1, Alexandre Coimbra1 1Imaging, Merck, West Point, Pa, United States; 2Central Pharmacology, Merck, West Point, Pa, United States While numerous studies have used MRI techniques for studying stroke pathology, there has been limited use of MR parameters as in vivo markers of novel treatment efficacy. Here, Gd-enhanced T1-w and T2-w MR data were used to verify the efficacy of pre- and post-infarct treatment with a novel KDR kinase inhibitor (KDRi) known to reduce vascular permeability and therefore, BBB leakage. In line with previously published ex-vivo data (1), in-vivo MRI results suggest efficacy of KDRi treatment in reducing BBB leakage and edema formation, as indicated by tissue water content. 2241. Longitudinal Assessment of Brain Damage in Hypertension Rats Using Diffusion Tensor Imaging Chien-Yuan Lin1, Cheng-Di Chiu2,3, Ming-Huang Lin1, Wai-Mui Cheung1, Teng-Nan Lin1, Chen Chang1 1Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan; 2Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan; 3Department of Neurosurgery, Chang-Hua Hospital, Chang-Hua, Taiwan The elevated blood pressure is considered to be the main risk factor of stroke and is highly associated with white matter lesions. This study aimed to investigate the change of white matter microstructure under various levels of blood pressures. 2242. MRI Monitoring of Endogenous Stem Cell Therapies in Animal Models of Stroke Voytek Gretka1, Lisa Di Diodato1, Amy Hoyles2, Nancy J. Lobaugh3, Cindi Morshead2, Greg J. Stanisz1 1Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; 2Department of Surgery, University of Toronto, Toronto, ON, Canada; 3Cognitive Neurology, Sunnybrook Health Sciences Centre, Toronto, ON, Canada In animal models of stroke, endogenous neural precursor cells can be activated with growth factors such as epidermal growth factor (EGF) and erythropoietin (EPO) leading to increased neurogenesis and behavioural recovery. We demonstrated the feasibility of using MR to distinguish between regenerating and pathological tissues when using endogenous stem cell therapies in rats. Tissue growth in the lesion site has MR characteristics (T1 and T2) similar to that of normal brain tissue, and differs distinctly from the cavity present when animals are untreated. MRI is able to predict the outcome of the treatment as early as 2 weeks post stroke. William Matthew Holmes1, Maria Rosario Lopez Gonzalez2, Lindsay Gallagher1, Graeme A. Deuchar1, I M. Macrae1, Celestine Santosh3 1GEMRIC, Wellcome Surgical Institute, Univeristy of Glasgow, Glasgow, United Kingdom; 2SINAPSE, Clinical Physics, University of Glasgow, Glasgow, United Kingdom; 3Institute of Neurological Sciences, Southern General Hospital, Glasgow, United Kingdom One of the most important considerations when treating acute stroke patients is to establish whether potentially salvageable (penumbral) tissue is still present within the brain. Currently perfusion-diffusion mismatch MRI is used, which is an indirect measure lacking precision . Here we propose a new MRI method for imaging the ischaemic penumbra based on the brains capacity to use lactate as a metabolic substrate. Spectroscopic imaging is used to map the changes in tissue lactate induced by giving a challenge of 100% oxygen. 2244. Estimation of the Onset Time of Cerebral Ischemia in Rats Using T1ρ MRI Kimmo T. Jokivarsi1, Yrjö Hiltunen2, Heidi I. Gröhn3, Olli H. Gröhn1, Risto A. Kauppinen4 1Department of Neurobiology, A.I.Virtanen -Institute, Kuopio, Finland; 2Department of Environmental Science, University of Kuopio, Kuopio, Finland; 3Department of Clinical Physiology, Nuclear Medicine and Neurophysiology, North Karelia Central Hospital, Joensuu, Finland; 4Department of Radiology, Dartmouth Medical School, Hanover, NH, United States MRI parameters can be used to acquire information about stroke and its progression. We investigated the prediction potential of absolute T1ρ in cerebral ischemia in a rat stroke model. Our results show that δT1ρ can give an accurate estimate of ischemia time. Clinically this method provides an easy and fast MR method for ischemia time estimation that can be used in the absence of a priori knowledge or as an additional confirmation for the clinical estimate of stroke onset. 2245. Artificial Neural-Network Prediction of Ischemic Tissue Fate in Acute Stroke Imaging Shiliang Huang1, Qiang Shen1,2, Timothy Q. Duong1,2 1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States; 2Department of Ophthalmology/Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States A flexible artificial neural network (ANN) algorithm was developed and applied to predict ischemic tissue fate on three stroke groups: 30-min, 60-min and permanent MCAO in rats. CBF, ADC and T2 were acquired during the acute phase up to 3hrs and again at 24hrs followed by histology. Infarct was predicted pixel-by-pixel using only acute (30-min) stroke data. Receiver-operating-characteristic analysis was used to quantify prediction accuracy. It was concluded that the ANN predictive model has the potential to serve as promising metrics for diagnosis, prognosis and therapeutic evaluation of acute stroke. 2246. Prolonged Post-Ischemic Hyperperfusion: A Systematic Multimodal MRI Study Qiang Shen1,2, Fang Du1, Shiliang Huang1, Timothy Q. Duong1,2 1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States; 2Ophthalmology/Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States Regional hyperperfusion after stroke is a frequent, yet poorly understood, phenomenon. In this study, multimodal MRI (diffusion, perfusion, T2, T1, pH-weighted and dynamic contrast-enhanced imaging, and MRA) were acquired in a 30-min transient MCAO in rat. Significant hyperperfusion was observed 24hrs post-occlusion and peaked at 48hrs. Hyperperfusion areas were consistent with regions with T1 and T2 increases, and early-phase pH decrease, and late-phase permeability changes. MRA showed significant vasodilatation of distal small arteries. We conclude that hyperperfusion does not appear to salvage tissue. Multimodality MRI investigation helps to gain significant insights into the underlying physiological changes associated with hyperperfusion. NRA & CSF Studies with Clinical Applications Hall B Tuesday 13:30-15:30 2247. Magnetic Resonance Angiography of the Mouse Cerebrovascular System at 17.6 T Firat Kara1, Alia Alia1 1Leiden Institude of Chemistry, Leiden University, Leiden, Netherlands As magnetic field strength increase toward higher fields , it allows significant improvements in MRI techniques by enhancing contrast to noise and signal to noise ratio. The use of magnetic resonance angiography (MRA) in ultra high magnetic field to visualize cerebrovascular structure of animals, promote development of early diagnosis and treatment of human neurodegenerative diseases. In this study, an improved contrast-to-noise ratio at 17.6 T imaging contribute to visualization the smaller vessels of the mouse brain. Branches of anterior cerebral artery (ACA)are better depicted on maximum intensity projections(MIP) with 17.6 T imaging than MIPs obtained with 9.4. Steffen Sammet1, Paula Martin-Vaquero2, Rita L. Echandi2, Ronaldo C. da Costa2, Christina L. Tosti1, Michael V. Knopp3 1Department of Radiology, The Ohio State University, Columbus, OH, United States; 2Veterinary Hospital, The Ohio State University, Columbus, OH, United States; 3Department of Radiolgy, The Ohio State University, Columbus, OH, United States The purpose of this study was to evaluate the ability of 2D ToF-MRA to depict cerebral arteries in the canine brain and to compare the results obtained from a high field magnet (3T) with an ultrahigh field magnet (7T). ToF-MRA at high and ultra-high magnetic fields should be included in the MRI imaging protocol of dogs suspected of having cerebrovascular disease. 7T field ToF-MRA allows a better delineation of small vessels in the canine brain than 3T ToF-MRA. Melanie Heilmann1, Hanne Boll2, Sebastian J. Schambach2, Christoph Groden2, Marc A. Brockmann2, Lothar R. Schad1 1Computer-Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Neuroradiology, University Medicine Mannheim, Germany Quantitative dynamic MRI requires knowledge of contrast agent (CA) concentration in blood. Due to the small size of murine vessels, so far an arterial input function (AIF) has only been measured in mouse hearts. Using a novel cryogenic probe at 9.4 T, we measured CA kinetics in intra- and extracranial vessels. Although high inter-individual variations were observed, in average, kinetics of the superficial temporal vein provided good estimates for blood CA concentration. Smaller vessels suffered from partial volume effects but were less prone to inter-individual variations. Whether mouse perfusion studies benefit from vessel-based AIFs, remains to be studied in future. Yi-Jui Liu1,2, Chun-Jung Juan3, Teng-Yi Huang4, Hsiao-Wen Chung5, Cheng-Yu Chen3 1Department of Automatic Control, Feng Chia University, Taichung, Taiwan; 2Master's Program in Biomedical Informatics and Biomedical Engineering, Feng Chia University, Taichung, Taiwan; 3Department of Radiology, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan; 4Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; 5Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan The purpose of this study was to evaluate the cerebral blood change in one cardiac cycle in different concentration of carbon dioxide inhalation. Using retrospectively gated 2D phase contrast MRI is suitable method for measuring the velocity of cerebral arteries and veins during one hear beat. It is noninvasive modality to quantify the blood flow and blood volume in one heart cycle with high spatial and temporal resolution. By this MR method, we proceeded the experiment that observe the blood flow change during the CO2 concentration change. 2251. Quantification of Carotid Artery Blood Flow Before and After the Acetazolamide Challenge Josephine Mary Reeve1, Dinesh Selvarajah2, Nyssa Craig1, Paul David Griffiths1, Solomon Tesfaye2, Iain D. Wilkinson1 1Academic Radiology, University of Sheffield, Sheffield, S Yorkshire, United Kingdom; 2Diabetes, Royal Hallamshire Hospital, Sheffield, S Yorkshire, United Kingdom Cerebrovascular reserve or the ability to vasodilate under stress may be a crucial physiological mechanism, providing increased arterial flux when necessary. This study quantified flow within the internal carotid artery (ICA) in 14 normal young adults before and after administration of a carbonic anhydrase inhibitor (acetazolamide). Quantitative flow assessment was based on a single-slice, multi-phase, fast-field echo sequence. Data was extracted via ROI analysis. Significant increases in velocity, flux, apparent vessel diameter but not heart rate were observed following acetazolamide. This assessment provides an objective in-vivo marker of the functional reserve of the macrovascular supply system. 2252. Towards True Arterial Intracranial TOF-MRA at 7T: Protocol Optimization Using VERSE Pulses Soeren Johst1, Sebastian Schmitter2, Armin Nagel1, Wolfhard Semmler1, Michael Bock1 1Medical Physics in Radiology, German Cancer Research Center (dkfz), Heidelberg, Germany; 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States TOF MRA highly profits from high fields, however, SAR restrictions limit the use of high-resolution protocols. In particular, venous suppression with saturation pulses is difficult within clinically acceptable measurement times (TA ”Ü 10min). Using the VERSE algorithm on the excitation pulses as well as on the energy-intensive saturation pulses permits an effective SAR reduction that can be used to shorten the acquisition time. With a modified TOF MRA pulse sequence high resolution intracranial MRA data sets with excellent venous suppression could be acquired in 10 min at 7 Tesla. 2253. Fast Inversion Recovery Magnetic Resonance Angiography (FIR-MRA) of the Intracranial Arteries Ek Tsoon Tan1, John Huston III1, Norbert G. Campeau1, Stephen J. Riederer1 1Radiology, Mayo Clinic, Rochester, MN, United States Spin-labeling-based FIR-MRA can provide high resolution 3D intracranial MRA. A detailed comparison of FIR-MRA (7.7 min) to standard 3D time-of-flight (TOF) MRA (6.5 min) was performed at 3 Tesla. Superior or equal vessel conspicuity, continuity, and venous suppression were demonstrated in eight normal subjects with FIR-MRA. Three clinical studies were performed. In two patients with coiled aneurysms, FIR-MRA provided superior depiction of aneurysm remnants to TOF. In one arteriovenous malformation (AVM) patient, FIR-MRA provided a clearer depiction of the AVM nidus than TOF and contrast-enhanced MRA, and could differentiate between the arterial and venous components of the AVM. 2254. Assessment of the Supra-Aortic Vessels Using Time-Resolved Double-Bolus 3D TWIST-MRA Andreas Korn1, Till K. Hauser1, Sören Danz1, Benjamin Bender1, Michael Fenchel1, Thomas Nägele1, Ulrike Ernemann1, Uwe Klose1 1Department of Neuroradiology, University Hospital Tübingen, Tübingen, Germany MRA of the supra-aortic vessels is usually performed in CARE bolus technique, which necessitates high operator experience and interaction with the control panel. TWIST requires less operator experience and interaction. Goal of the present work was to implement an automated and therefore robust protocol for the TWIST angiography of the supra-aortic vessels with high spatial resolution and increased likelihood of optimal arterial contrast by double bolus injection. The new double bolus injection protocol allowed for good separation of arterial vessels at least after one of the two bolus applications. 2255. High Resolution 3D Intracranial Imaging at 3.0T Yiu-Cho Chung1, Steven Shea2, Ye Qiao3, Orlando P. Simonetti4, Bruce Wasserman3 1Siemens Medical Solutions USA, Inc., Columbus, OH, United States; 2Siemens Corporate Research, United States; 3Johns Hopkins University, United States; 4The Ohio State University, United States Minor Outlying Islands Intracranial artery imaging is usually done by 2DTSE. However, the technique has long scan time, and has very limited anatomical coverage. We propose here the use of T1w-SPACE, a variant of TSE, for 3D imaging of the intracranial vessels. Using a 32 channel head coil at 3.0T, the technique achieves a spatial resolution of (0.5mm)3, comparable to CT, in less than 11minutes. The technique can cover both sides of the tortuous ICA and MCA in one scan. SNR comparison found that the 3D technique has consistently higher SNR than 2DTSE. Bharathi Dasan Jagadeesan1, Josser E. Delgado Almandoz2, Tammie Benzinger2, Christopher Moran2 1Neuroradiology, Washington University School of Medicine , St Louis, MO, United States; 2Neuroradiology, Washington University School of Medicine, St Louis, MO, United States We retrospectively evaluated the utility of susceptibility weighted imaging (SWI) in the detection of arterio-venous shunting (AVS) in 47 patients with 66 brain vascular malformations (BVM) identified on digital subtraction angiography (DSA). AVS was considered to be present if there was hyperintensity in a vein adjacent to the BVM. Overall, SWI had a sensitivity of 93%, specificity of 100% and accuracy of 97% for the detection of AVS. In the 13 BVMs associated with hemorrhage, SWI had sensitivity and specificity of 100%. In the 53 BVMs not associated with hemorrhage, SWI had a sensitivity of 92% and specificity of 100%. 2257. Comparative Study of 3.0- And 1.5-T MR in the Follow-Up of Moyamoya Disease Qianna Jin1, Tomoyuki Noguchi1, Hiroyuki Irie1, Masashi Nishihara1, Tetsuyoshi Hirai1, Masatou Kawashima2, Toshio Matsushima2, Sho Kudo1 1Radiology, Saga University Hospital, Saga, Japan; 2Neurosurgery, Saga University Hospital, Saga, Japan To retrospectively compare 3.0- and 1.5-T magnetic resonance (MR) findings in patients with moyamoya disease (MMD), and assess the relationship and difference between those two modalities in the follow-up of MMD. 60 (120 sides) MMD patients (15 male and 45 female patients, age range: 5 to 60 years, post/pre-operative patients: 44/ 16) were included. We got different upgrading rate among one-year interval follow-up with 1.5- and 3.0-T MR in different orders. Regardless of disease progressing, we should be careful about 1.5-T MR in evaluating steno-occlusive severity of intracranial vessels in MMD for its higher overestimating rate compared with 3.0-T MR. Christof Karmonik1, Yi J. Zhang1, Orlando Diaz2, Richard Klucznik2, David Purdy3, Robert G. Grossman1 1Neurosurgery, The Methodist Hospital Neurological Institute, Houston, TX, United States; 2Radiology, The Methodist Hospital Neurological Institute, Houston, TX, United States; 3Siemens Healthcare, Malvern, PA, United States Complex flow patterns in cerebral aneurysms have been identified by computational fluid dynamics (CFD) studies to potentially be predictive of aneurysm rupture. Here, we quantified the stability of blood flow patterns in cerebral aneurysms in vivo based on flow features in 2D pcMRI images in seven aneurysms. A stability index (SI) defined as the area fraction (in percent) exhibiting sign changes of the through-plane velocity was calculated. Average SI range was 1.3%-20.6%. Average SI and aneurysm size were linearly correlated (R=0.796). Further studies are warranted to explore the potential of the average SI as a marker for aneurysm rupture. Elan J. Grossman1, Yulin Ge1, Matilde Inglese1, Ke Zhang1, Jing An2, Ding Xia1, Jian Xu3, Niels Oesingmann3, Kelly A. Mcgorty1, Joseph Reaume1, Robert I. Grossman1, Qun Chen1 1Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, United States; 2Siemens Medical Solutions, Beijing, China; 3Siemens Medical Solutions, Malvern, PA, United States Conventional imaging fails to reveal evidence of damage in mild traumatic brain injury (MTBI) that accounts for its disabling impairments. The purpose of the current study is to examine if perfusion changes in thalamus and basal ganglia can be a possible indicator of pathology in acute MTBI. We have employed segmented True-FISP ASL, which we recently developed to measure perfusion in deep gray matter at high spatial resolution. Results indicate there are significant differences between patients and controls in thalamus and caudate. This suggests these regions may exhibit hypoperfusion in acute MTBI and could be biomarkers of persistent post-concussive syndrome. Pim van Ooij1, Annetje Guédon2, Christian Poelma3, Joppe J. Schneiders4, Charles B. Majoie4, Jenny Dankelman2, Ed vanBavel1, Aart J. Nederveen4 1Biomedical Engineering & Physics, Academic Medical Center, Amsterdam, Noord-Holland, Netherlands; 2Biomechanical Engineering, Delft University of Technology, Delft, Netherlands; 3Laboratory for Aero and Hydrodynamics, Delft University of Technology, Delft, Netherlands; 4Radiology, Academic Medical Center To validate 4D blood flow velocity measurements in intracranial aneurysms using phase contrast MRI, a real-size glass phantom of an intracranial aneurysm was created and used for blood flow velocity measurements using PC-MRI and PIV. Resolution of PC-MRI was 0.5x0.5x0.5 mm and took 70 minutes to scan. Both steady and pulsatile flow measurements in MRI and PIV produced similar flow patterns of similar magnitude, although more noise was found in the MR results. Velocity to noise ratio will improve with more accurate velocity encoding settings. More importantly, to be able to apply the PC-MRI scan in patients, scan time needs to be shortened severely, for example by acceleration techniques. Nolan S. Hartkamp1, Reinoud P.H. Bokkers1, H. B. van der Worp2, L. J. Kappelle2, M. P.J. van Osch3, Willem P.T.M. Mali1, Jeroen Hendrikse1 1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Department of Neurology, University Medical Center Utrecht, Utrecht, Netherlands; 3Department of Radiology, Leids University Medical Center, Leiden, Netherlands For patients with a symptomatic internal carotid artery (ICA) stenosis, it is often difficult to identify the symptomatic artery for treatment due to the variability in perfusion territories of the major cerebral arteries. For the basal ganglia, this imposes an even greater difficulty. Using selective arterial spin-labeling MRI, this study found the nucleus caudatus in patients with a symptomatic ICA stenosis was more often fed by the contralateral ICA compared to healthy control subjects (p=0.03). This was accompanied by reversed blood flow through the ipsilateral anterior part of the circle of Willis (p<0.01). Qi Liu1, Ping jian Lu1, Fei Wang1, li Wang1 1Radiology, Changhai Hospital, Second Military Medical University, Shanghai, China Cerebral arteriovenous malformations are congenital vascular lesions with dilated feeding arteries and draining veins without an intervening capillary bed. Treatment is recommended for most patients because of the risk of hemorrhage, which largely dependent on the imaging information available before treatment. Three-dimensional contrasted-enhanced MR angiography combined with MRI, as a noninvasive technique with the advantages of arterial angiography, can depict the feeding arteries, venous drainage pattern, nidus, and provide more accurate localization of the nidus, adjacent brain anatomy. These data are important for the planning of surgical resection, endovascular embolization and radiotherapy. 2263. Flow-Sensitive Black Blood Imaging : Clinical Intracranial Applications Vijay Sawlani1, J Spark2, Faiza Admiraa-Behloul3 1Radiology, Morriston and Singleton hospitals ABM university NHS trust, Swansea, United Kingdom; 2Morriston and Singleton hospitals ABM university NHS trust, Swansea,, United Kingdom; 3MR-BU, Toshiba Meidcal Systems Europe, Zoetermeer, Netherlands Susceptibility-weighted imaging (SWI) is sensitive to venous vasculature and is a powerful tool for evaluating vascular malformations such as venous angiomas. To enhance the visibility of small vascular structures, especially at 1,5T systems, a flow-sensitive black-blood (FS-BB) has been recently developed; The purpose of this study is to evaluate the utility of the FS-BB sequence in various intracranial lesions apart from vascular malformations. 2264. Characterization of Carotid Plaque in-Vivo and ex-Vivo Using MRI, CTA and Histology Maria Rosario Lopez Gonzalez1, William Matthew Holmes2, William Stewart3, Keith W. Muir4, Barrie Condon, George Welch5, Kirsten Forbes 1SINAPSE, Clinical Physics, University of Glasgow, Glasgow, United Kingdom; 2GEMRIC, Wellcome Surgical Institute, Faculty of Medicine, University of Glasgow, Glasgow, United Kingdom; 3Department of Neuropathology, Institute of Neurological Sciences, Southern General Hospital, Glasgow, United Kingdom; 4Division of Clinical Neurosciences, University of Glasgow, Glasgow, United Kingdom; 5Vascular surgery, Southern General Hospital, Glasgow, United Kingdom In-vivo 3T MR and CTA images were acquired of symptomatic stroke patients. These images show that most of the patients presented high degrees of atherosclerotic carotid plaque. To help to identify unstable and vulnerable plaques, segmentation of the different plaque components was carried out by using a semiautomatic thresholding method. Half of the patients underwent surgical excision of the carotid plaque. The specimens obtained were imaged in a 7T scanner. The specimens were sectioned and stained with heamatoxylin-eosin and Elastin van Gieson. Correlation of the MRI datasets and Histology was carried out. Dariusch Reza Hadizadeh1, Guido Matthias Kukuk1, Jürgen Gieseke1, Arne Koscielny2, Frauke Verrel2, Jack Boschewitz1, Ute Fahlenkamp1, Hans Heinz Schild1, Winfried Albert Willinek1 1Radiology, University of Bonn, Bonn, NRW, Germany; 2Vascular surgery, University of Bonn, Bonn, NRW, Germany Vessel wall enhancement may serve as a potential marker for identification of high-risk atherosclerotic plaques. 3D-MRA and plaque enhancement at the level of the carotid bifurcation were assessed after application of the blood pool contrast agent gadofosveset trisodium and Gd-DTPA at 3.0 Tesla. 24h after injection of Gd-DTPA, no remaining vessel wall enhancement was observed, whereas remaining vessel wall enhancement (10% in atherosclerotic plaque and 2% in non-diseased vessel walls) was observed after injection of Gadofosveset Trisodium. Residual vessel wall enhancement 24h after injection of gadofosveset trisodium may reflect neo-vessel density and be a predictor for future ischemic events. Yoko Saito1, Minoru Osanai2, Kazuhiko Oyu2, Keito Hamada2, Hiraku Yodono3 1Graduate School of Health Sciences, Hirosaki University , Hirosaki, Aomori, Japan; 2Graduate School of Health Sciences, Hirosaki University, Hirosaki, Aomori, Japan; 3Radiology, Narumi Hospital, Hirosaki, Aomori, Japan We evaluated the stenotic degree of arteries at the skull base level which are demonstrated on both 3D-TOF MRA and CE-MRA in 139 cases (659 vessels ). The discrepancy between these two technique in grading steotic degree occurred in 80 arteries. The stenotic grading were more severely estimated with CE MRA than with TOF MRA.We also performed phantom study. TOF-MRA tended to demonstrate the phantom more accurately than CE-MRA. On TOF-MRA with 1.6mm slice thickness, diameters were most accurately demonstrated. In CE-MRA, diameters of the tube were significantly more accurate with parallel imaging than with ZIP. 2267. Direct Visualization and Quantitation of CSF Flow in Shunts Noam Alperin1,2, Sang H. Lee1, Leonardo Macedo3, Daniele RigamontI4, Ari Blitz3 1University of Miami, Miami, FL, United States; 2Radiology, University of Miami, United States; 3Radiology, Johns Hopkins, Baltimore, MD; 4Nuerosurgery, Johns Hopkins, Baltimore, MD Diversion of excessive CSF from hydrocephalic brains by shunting is, in many cases, a life saving procedure. The down side of shunting is high failure rate. Consequently, about 40% of the shunting procedures performed annually in the US are for shunt replacement. The decision for shunt replacement is challenging as there is no reliable noninvasive test for shunt function. We present the first direct visualization and quantitation of CSF flow in ventricular shunts using high temporal and spatial resolution cine phase contrast MR and automated flow quantitation technique. Volumetric flow rate through in patent shunts were on the order of the CSF production rate. Manganese - Enhanced MRI Hall B Wednesday 13:30-15:30 Der-Yow Chen1, Stephen J. Dodd, Daniel R. Glen, Ziad S. Saad, Alan P. Koretsky 1NINDS, National Institutes of Health, Bethesda, MD, United States MEMRI can be used for neuronal tracing in the brain. Here it is demonstrated that MEMRI identifies the laminar connections of the olfactory system and traces layer-specific inputs to olfactory cortices. MnCl2 was injected into nostrils or the olfactory bulb of rats, and they were imaged with this MRI technique at several time points. The dynamic changes of Mn2+ enhancement could be characterized by the arrival latency into each specific region. The olfactory pathway from olfactory bulb to higher-order cortex was labeled in proper, known laminar order. Mn2+ enhancement into the orbitofrontal cortex predicts that connections from olfactory cortex innervate superficial layer of the orbitofrontal cortex. This is a connection that has not been previously mapped. Therefore, MEMRI neural tracing is specific at the level of cortical layers in the olfactory pathway. Philippe Garteiser1, Bruce A. Berkowitz2,3, Debbie Saunders1, Rebecca Cranford1, Rheal A. Towner1, Michael H. Elliott4 1Advanced Magnetic Resonance Center, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States; 2Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI, United States; 3Department of Ophthalmology, Wayne State University, Detroit, MI, United States; 4Department of Ophtalmology, Dean A McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States Mn-enhanced MRI (MEMRI) has recently emerged as an important tool in retinal function studies. Caveolin-1 (Cav-1), the principal protein member of caveolar membrane domains, is believed to be essential to blood-retinal barrier integrity and ion homeostasis of the retina. Here, we evaluate how MEMRI and other MRI techniques may detect functional disruptions induced by cell type-specific knock out of the Cav-1 gene in mice. The MEMRI signature of light and dark adaptation and the dynamic gadolinium-enhanced signal behavior of iodate-induced retinal impairments indicate that both methods have sufficient sensitivity to warrant their application to cell-type specific Cav-1 ko mice. Eric Raymond Muir1,2, Bryan H. De La Garza2, Sung-Hong Park3, Timothy Q. Duong2 1Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States; 2Research Imaging Institute, Ophthalmology/Radiology, UT Health Science Center San Antonio, San Antonio, TX, United States; 3Research Imaging Institute, Radiology, UT Health Science Center San Antonio, San Antonio, TX, United States Anatomical MRI of the retina has previously reported 3-4 layers in the rodent retina using conventional gradient echo (GE) and spin echo MRI. Following intraocular injection of manganese, seven layers were detected previously. This study explored balanced steady state free precession (bSSFP) MRI to image the mouse retina at 35x35x200 µm. Moreover, we compared GE and bSSFP with and without intraocular manganese injection. We demonstrated that bSSFP can reveal 7 layers without using contrast agent. Layers detected by bSSFP without manganese were consistent with those of manganese-enhanced MRI and histology. Taeko Inoue1, Robia G. Pautler1 1Dept. of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, United States Axonal transport is an important cellular mechanism necessary for the normal function and viability of a neuron. As a result, deficits in axonal transport have become associated with the development and progression of human diseases such as diabetes and neurodegenerative diseases such as Alzheimers disease. Here we demonstrate the potential of Manganese Enhanced MRI (MEMRI) for measuring in vivo deficits of axonal transport in two mouse models of human disease. Mohammed Khair Hankir1,2, James R. Parkinson1, Stephen R. Bloom3, Jimmy David Bell1 1Metabolic and Molecular Imaging Group, Imperial College, London, United Kingdom; 2Investigative Medicine, Imperial College , London, United Kingdom; 3Investigative Medicine, Imperial College, London, United Kingdom Peripheral administration of monosodium glutamate (MSG) stimulates feeding in rodents. This may be due to the direct activation of glutamate receptors expressed in the arcuate nucleus (ARC) of the hypothalamus. We have used manganese enhanced MRI (MEMRI) to demonstrate that intraperitoneal administration of MSG dose dependently increases Mn2+ influx into the ARC and that this can be suppressed with a glutamate receptor subtype specific receptor antagonist. These results reveal that MEMRI is a sufficiently sensitive tool to detect glutamatergic signalling in vivo with high temporal and spatial resolution. Tammar Kushnir1, Shaye Kivity2, Eli Konen1, David Manor1, Nancy Agmon-Levin2, Miri Blank2, Joab Chapman3, Yehuda Shoenfeld2, Galia Tsarfaty1 1Dept. of Diagnostic Imaging, MRI Unit, The Chaim Sheba Medical Center, Tel Hashomer, Israel; 2Center of Autoimmune Diseases, The Chaim Sheba Medical Center, Tel Hashomer, Israel; 3Dept. of neurology, Sagol Neuroscience Center, The Chaim Sheba Medical Center, Tel Hashomer, Israel Manganese enhanced MRI (MEMRI) allows in-vivo mapping of functional neuronal connections in the brain. The method was used to investigate the olfactory system in mice with experimental neuropsychiatric lupus (NPSLE), induced by intra-cerebro-ventricular injection of anti-ribosomal-P antibodies. MEMRI scans were performed before and 40 hours after intranasal MnCl2 administration. NPSLE induction resulted in a depression-like behavior accompanied with a significant deficit in olfactory function. MEMRI demonstrated impaired olfactory neuronal function expressed as a significant reduction in normalized manganese enhancement and flow throughout of the olfactory pathway, compared to healthy mice. Our results propose that autoimmune-CNS conditions may influence olfactory function. 2274. Oral Manganese as an MRI Contrast Agent for the Detection of Nociceptive Activity Kathleen Elizabeth Jacobs1, Deepak Behera1, Garry Gold1, Michael Moseley1, Jarrett Rosenberg1, David Yeomans2, Sandip Biswal1 1Radiology, Stanford University, Stanford, CA, United States; 2Anesthesia, Stanford University, Stanford, CA, United States Manganese-enhanced magnetic resonance imaging (MEMRI) is a potentially powerful diagnostic method for identifying neural regions of pain processing for image-guided interventions. Manganese can enter nerves via voltage-gated calcium channels, which are selectively upregulated in pain. We gave manganese by oral gavage to two rat groups: one with spared injury of their sciatic nerves and a sham-operated group. We found that rats with spared nerve injury have increased manganese ion uptake and retention in their nerves compared to the nerves of sham-operated rats as shown by increased MR signal and nerve concentrations. Therefore, manganese can specifically enhance nerves associated with nociception. MRI of Neural Plasticity Hall B Thursday 13:30-15:30 2275. In Vivo Detection of Axonal Plasticity in Rat Hippocampus Using DTI Teemu Laitinen1, Alejandra Sierra1, Asla Pitkänen1, Olli Gröhn1 1A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, Kuopio, Finland The ability of in vivo diffusion tensor imaging to detect axonal plasticity in dentate gyrus sub region of hippocampus was studied in rats after kainic acid induced status epilepticus. Our results show that fractional anisotropy of dorsal dentate gurys is increased 17 months after the brain injury when compared to healthy control animals. Histological evaluation showed significant increase in the density of mossy fiber sprouting and myelinated axons the kainic acid treated animals, consistent with the DTI results. The results of this study suggest that axonal plasticity can be detected using in vivo DTI. 2276. Short-Term Learning Induced Plasticity Visualized with Diffusion MRI shimrit Tzur-Moryosef1, tamar Blumenfeld-Katzir2 1tel aviv university, tel aviv, Israel; 2neurobiology, tel aviv university, tel aviv, Israel Plasticity in the adult brain following learning procedure is commonly attributed to functional plasticity and restricted to the hippocampus. This study we utilize Magnetic diffusion tensor imaging (DTI) in order to characterize microstructural plasticity induced by short-term learning paradigm. Analyses were done by ADC and FA parameters in order to characterize both white and gray matter changes. Rats were scanned before and one day after a one-day version of the Morris water maze task. Paired t-test comparisons demonstrate FA increase in the cingulum bundle and FA and ADC decrease in striatum-related gray matter, motor and sesorimotor cortex. Hua-Shan Liu1, Hui Shen1, Hanbing Lu1, Jenny Chou1, April P. Zhu1, William Rea1, Yun Wang1, Yihong Yang1 1National Institute on Drug Abuse, Baltimore, MD, United States There is considerable evidence to suggest that amphetamine can improve functional outcome in animal model of stroke, which is involved in the mechanisms of induced axonal growth and reinnervation of brain tissues. In this study we used DTI to assess changes in perilesional tissue integrity after amphetamine treatment in a rat stroke model. We found that FA showed a significantly higher increase under the influence of amphetamine after 25 days. 2278. Learning Is Necessary for Training Induced Brain Plasticity Jason Philipp Lerch1, Amanpreet Badhwar2,3, Edith Hamel2, John G. Sled1 1Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada; 2McGill University, Montreal, Quebec, Canada; 3 (contributed equally to this abstract) Here we used a mouse model of Alzheimers Disease (AD) with impaired spatial learning to test whether a capacity to learn is necessary for training induced MRI detectable volume changes to occur. Mice were trained on two different versions of the Morris Water Maze, fixation perfused and scanned overnight at 32 µm isotropic resolution. As hypothesized, hippocampal based spatial learning was impaired in AD mice, whereas striatum dependent non-spatial learning was equivalent between AD and wild-type mice. The data presented herein thus indicates that learning is a requirement for MRI detectable plasticity. fMRI in Brain Diseases Hall B Monday 14:00-16:00 Sandhitsu R. Das1, Dawn Mechanic-Hamilton2, Marc Korczykowski2, John Pluta2, John A. Detre2, Paul A. Yushkevich1 1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States We present preliminary data demonstrating the use of postmortem hippocampus atlas to study activation asymmetry in patients with unilateral temporal lobe epilepsy Willem M. Otte1,2, Rick M. Dijkhuizen2, Cornelis J. Stam3, Kajo van der Marel2, Maurits P.A. van Meer1,2, Max A. Viergever2, Kees P.J. Braun1 1Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, Netherlands; 2Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 3Department of Clinical Neurophysiology, VU University Medical Center, Amsterdam, Netherlands There is increasing evidence that the topology of brain networks may be changed in epilepsy. In particular, a random topology has been suggested as an explanation for lower seizure thresholds. To test this hypothesis, we assessed focal epileptic and healthy networks over time using resting state functional MRI and weighted graph theoretical analysis in a rat model. Brain networks in focal epilepsy were globally affected, toward a more ordered network topology. Networks largely normalized at ten weeks after epilepsy induction. Graph analysis provides a promising method to explore dynamical network alterations in epilepsy. Gaelle Bettus1,2, Fabrice Bartolomei2, Sylviane Confort-Gouny1, Eric Guedj1, Patrick Chauvel2, Patrick Cozzone1, Jean-Philippe Ranjeva1, Maxime Guye1 1CNRS UMR6612 CRMBM-CEMEREM, Marseille, France; 2INSERM U751 Epilepsie et Cognition, Marseille, France We aimed at determining the ability of resting-state functional connectivity MRI (fcMRI) to lateralize/localize the epileptogenic zone in mesial temporal lobe epilepsy (MTLE) at the individual level. Basal functional connectivity (BFC) was evaluated in 22 MTLE patients compared to 36 controls using a single shot GE-EPI sequence at rest. In patients, BFC was characterized by bilateral decreases predominant in the epileptic side, and unilateral increases almost exclusively observed in the contralateral (non-epileptic) side. We suggest that fcMRI is a useful technique that could be added to the presurgical assessment of drug-resistant partial epilepsies. 2282. Analysis of Simultaneous EEG/fMRI Data in Epileptic Patients Using ICA and GLM Based Methods. Marco Carnģ1,2, Carlo Di Bonaventura3, Giovanni Giulietti4, Jinan Fattouch5, Anna Teresa Giallonardo6, Anna Elisabetta Vaudano6, Valter Nucciarelli6, Mario Manfredi6, Massimiliano Prencipe6, Vittorio Cannatą1, Bruno Maraviglia2 1Department of Occupational and safety- Medical Physics-, Bambino Gesł Children's Ospital,Scientific Istitute (IRCCS), Rome, Italy; 2Department of Physics University of Rome La Sapienza, MARBILab Enrico Fermi Center, Rome, Italy; 3Department of Neurology,, University of Rome Sapienza, Rome, Italy; 4Department of Physics University of Rome La Sapienza, MARBILab Enrico Fermi Center,, Rome, Italy; 5Department of Neurology, University of Rome Sapienza,, Rome, Italy; 6Department of Neurology, University of Rome Sapienza, Rome, Italy In this study we applied two different methods to analyze fMRI data, acquired simultaneously with EEG, coming from experiments involving patients with Idiopathic Generalized Epilepsy or with Cryptogenic Partial Epilepsy. We used first the data driven ICA (Independent Components Analysis) on fMRI data, while in the second approach we applied the GLM (General Linear Model) on the same data, but exploiting the EEG recording to compute the regressor. ICA and GLM analysis detected either activation areas located in agreement with presumed electroclinical hypothesis and the BOLD patterns of activation in response to synchronized ictal activity. Victoria L. Morgan1, Xiaoyun Liang1, John C. Gore1, Bassel Abou-Khalil2 1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 2Neurology, Vanderbilt University, Nashville, TN, United States Functional MRI (fMRI) has the potential for non-invasively localizing interictal epileptic activity more accurately than other clinical methods. Currently the gold standard for detecting the timing of interictal activity during the fMRI scan is simultaneous electroencephalography (EEG). The objective of this work is to compare a data-driven method, 2dTCA, to EEG/fMRI in temporal lobe epilepsy. Overall, there was good qualitative agreement between the two methods with the 2dTCA maps showing more mesial temporal activation concurring with the presumed epileptogenic region in these patients, without the need for the additional hardware, software, analyses and scalp EEG spikes required for EEG/fMRI. 2284. On the Advantage of Data Driven Analysis in Aphasic Patients with Severe Language Latency Maria Engström1, Mattias Ragnehed2, Peter Lundberg3 1IMH/Radiological Sciences/CMIV, Linköping University, Linköping, Sweden; 2IKE/Technical Audiology/CMIV, Linköping University; 3IMH/Radiation Physics/CMIV, Linköping University Language fMRI in aphasic patients are exceptionally challenging. The patients often have latency in responding to cognitive tasks. Using a data-driven approach for analysis might enable extraction of language networks even if the task is not performed at the intended pacing. In this study, five patients with chronic aphasia were examined. Conventional analysis did not result in language activation in most patients. When using a data-driven approach, four out of five patients elicited language related networks. It was concluded that language areas in patients with aphasia could be extracted using data driven analysis even if the conventional fMRI analysis fails. Benedicte Descamps1,2, Pieter Vandemaele1,2, Harmen Reyngoudt1,2, Karel Deblaere1,2, Luc Leybaert3, Koen Paemeleire3,4, Eric Achten1,2 1Radiology, Ghent University, Ghent, Belgium; 2GIfMI, Ghent, Belgium; 3Basic Medical Sciences, Ghent University, Ghent, Belgium; 4Neurology, Ghent University Hospital, Ghent, Belgium In this study, single subject net hemodynamic responses to paired stimuli from patients with migraine without aura and controls are fitted using inverse logit functions and compared. We demonstrate that patients with migraine without aura do not show a decrease in amplitude of their interictal hemodynamic response to a second stimulus in a pair with 1 second interstimulus interval, whereas the control group shows hemodynamic refractory effects when looking at repetitive stimuli. The finding in this patient group may be the neurovascular correlate of the absence of electrophysiological habituation. 2286. Functional Connectivity After Fronto-Occipital Impact Mild Traumatic Brain Injury Elena Shumskaya1,2, Teuntje Andriessen2, David Norris1,3, Pieter Vos2 1Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Gelderland, Netherlands; 2Department of Neurology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands; 3Erwin L. Hahn Institute for Magnetic Resonance, Essen, Germany The objective of this study is to evaluate the alterations in the whole-brain functional connectivity after fronto-occipital impact mild traumatic brain injury (MTBI). We used the resting state fMRI to relate the cognitive deficits occurring after frontal-occipital impact MTBI to the disruptions in functional connectivity. We found the disintegration of prefrontal, temporal and parietal regions in resting-state networks of MTBI patients and showed that the disconnection between prefrontal regions underlies the decline in the rate of information processing. 2287. fMRI Study of Response to Semantic Cueing During Verbal Learning in TBI Rebecca Jo Chambers1, William M. Brooks1, JoAnn Lierman1, Laura E. Martin1, Amanda Bruce1,2, Brenda A. Kirchhoff3, Monica Kurylo, Linda Ladesich, George Varghese, Cary R. Savage1 1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States; 2University of Missouri - Kansas City; 3University of Missouri - St. Louis Following TBI, memory functioning is frequently disrupted, and patients may not benefit from cognitive rehabilitation therapy. In an fMRI study, participants responses were measured during a verbal learning task of semantically related or unrelated word lists. They were asked to first remember the words with no further instruction, and then were cued to the semantic nature of the task. Both groups benefitted from semantic cueing, but showed differential brain responses in left DLPFC, a region implicated in working memory. This finding may suggest that after TBI, patients must compensate with additional neural processing in DLPFC to benefit from semantic cueing. 2288. Adaptive Changes in Response Inhibition BOLD Responses Following Antidepressant Treatment Darragh Downey1, Karen Elizabeth Davies1, Shane McKie2, Gabriella Juhasz2, Ian Muir Anderson2, John Francis William Deakin2, Stephen Ross Williams1 1Imaging Science and Biomedical Engineering, University of Manchester, Manchester, Lancashire, United Kingdom; 2Neuroscience and Psychiatry Unit, University of Manchester, Manchester, Lancashire, United Kingdom We investigated adaptive changes in 5-HT signalling following sub-chronic antidepressant treatment in healthy controls performing a response inhibition paradigm. 24 healthy volunteers were provided with 20mg citalopram or placebo for 11 days and tested with a behavioural inhibition task after 14 days following a 3 day drug washout. Citalopram pre-treatment compared to placebo was associated with a reduced response bilaterally in the inferior frontal gyrus and BOLD increases in the right middle frontal gyrus, mid cingulate, precuneus and posterior cingulate when inhibiting responses. These findings suggest that chronic antidepressant treatment modifies 5-HT pathways involved in cognitive flexibility and inhibitory control. 2289. A Novel FMRI Task to Visualize Frontal Lobe Circuitry Associated with Transient Sadness Leslie Baxter1, Ryan Smith1, Richard Fadok1, Michael Purcell1, Seban Liu1, Josef Debbins1 1Neuroimaging, Barrow Neurological Institute, Phoenix, AZ, United States We developed a novel functional magnetic resonance imaging (fMRI) method designed to activate the subgenual anterior cingulate cortex (sACC) and other frontal regions during transient sadness. We sought to develop a task that would show sufficient and specific activation in individuals to be useful as a potential target for deep brain stimulation treatment (DBS). Harald Kugel1, Christina Sehlmeyer2,3, Udo Dannlowski2,3, Sonja Schoening2,3, Martin Pyka2,3, Astrid Veronika Rauch2,3, Katharina Domschke2, Bettina Pfleiderer1, Pienie Zwitserlood4, Walter Heindel1, Volker Arolt2, Carsten Konrad3,5 1Dept. of Clinical Radiology, University of Muenster, Muenster, NRW, Germany; 2Dept. of Psychiatry, University of Muenster, Muenster, NRW, Germany; 3Research Group 4, Interdisciplinary Center for Clinical Research (IZKF), University of Muenster, Muenster, NRW, Germany; 4Dept. of Psychology, University of Muenster, Muenster, NRW, Germany; 5Dept. of Psychiatry, University of Marburg, Marburg, HE, Germany The effect of the serotonin transporter polymorphism 5-HTTLPR and trait anxiety on amygdala activation during fear conditioning and extinction was investigated with fMRI. 32 volunteers were tested with a fear-conditioning paradigm, presenting neutral faces combined with an acoustic startle. Individual trait anxiety was determined with the State Trait Anxiety Inventory (STAI). Evaluation showed that trait anxiety and 5-HTTLPR polymorphism did not affect acquisition, but fear extinction. Trait anxious volunteers and carriers of the short s-allele showed less deactivation of the amygdala during extinction, demonstrating that they react strongly to fear stimuli, and they can extinct fear reactions less easily. Harald Kugel1, Sonja Schoening2,3, Almut Engelien2,3, Anette Kersting2, Cornelia Roestel2, Pienie Zwitserlood4, Wolfgang Lehmann5, Walter Heindel1, Volker Arolt2, Carsten Konrad6,7 1Dept. of Clinical Radiology, University of Muenster, Muenster, NRW, Germany; 2Dept. of Psychiatry, University of Muenster, Muenster, NRW, Germany; 3Research Group 4, Interdisciplinary Center for Clinical Research (IZKF), University of Muenster, Muenster, NRW, Germany; 4Dept. of Psychology, University of Muenster, Muenster, NRW, Germany; 5Dept. of Psychology, University of Magdeburg, Magdeburg, ST, Germany; 6Research Group 4, Interdisciplinary Center for Clinical Research (IZKF) , University of Muenster, Muenster, NRW, Germany; 7Dept. of Psychiatry, University of Marburg, Marburg, HE, Germany In order to investigate differences in neurobiological processes in patients with gender identity disorder, 11 male-to-female transsexual patients before, 11 patients during cross-sex hormone therapy, and 11 control males underwent fMRI while performing a sexually dimorph mental rotation paradigm. The transsexual subjects showed less activation in the left parietal cortex (BA 40). Activation patterns different from controls, i.e. distinct from their biological sex, did not change during hormonal treatment. 2292. Temporal Modulation in Connectivity Within the Salience Network in Autism Spectrum Disorder Juha Nikkinen1, Jukka Rahko2, Tuomo Starck1, Jukka Remes1, Ahmed Abou Elseoud1, Irma Moilanen2, Osmo Tervonen1, Vesa Kiviniemi1 1Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland; 2Department of Child Psychiatry, Oulu University Hospital, Oulu, Finland Temporal modulation in connectivity within the salience network (SN) has been investigated in autism spectrum disorder (ASD) utilizing group independent component analysis (ICA). Using the ICA mixing matrix time courses, connectivity between the components including SN structures, anterior insula (AI) and anterior cingulate cortex (ACC), was investigated. One IC was found to be focused at AI and ACC structure was shown to be detectable in two ICs, ventral ACC and dorsal ACC. As a result we show that the temporal modulation in connectivity is altered in ASD between the AI and ventral ACC components. 2293. Attachment Model Affects Brain Responses in Areas Related to Empathy and Maternal Behaviour Delia Lenzi1,2, Cristina Trentini3, Patrizia Pantano1, Emiliano Macaluso2, Gian Luigi Lenzi1,4, Massimo Ammaniti 1Dipartimento di Scienze Neurologiche, UniversitĆ di Roma "Sapienza", Roma, Italy; 2Neuroimaging Laboratory, Fondazione Santa Lucia, Roma, Italy; 3Department of Dynamic and Clinical Psychology, UniversitĆ di Roma "Sapienza", Roma, Italy; 4Centro per lo Studio delle Funzioni Mentali dellāUomo, UniversitĆ di Roma "Sapienza", Rome, Italy Within the Attachment theory , Securely attached people tend to have positive views of themselves and their relationships. They feel comfortable with intimacy and independence, balancing the two in their relationships. Dismissive-avoidant adults tend to suppress and hide their feelings, dealing with rejection by distancing themselves from partners. Using fMRI we show that Dismissive subjects during the observation of stimuli activating attachment and maternal feelings have a overall greater reaction when compared to Secure subjects, i.e. greatly activate areas related to empathy and emotions (mirror neuron and limbic system) and inhibit areas related to maternal behaviour (anterior cingulated cortex).
Mingwu Jin1, Victoria Pelak2, Tim Curran3, Marie Banich3, Rajesh Nandy4, Dietmar Cordes1 1C-TRIC and Radiology, University of Colorado Denver, Aurora, CO, United States; 2Neurology, University of Colorado Denver, Aurora, CO, United States; 3Institute of Cognitive Science, University of Colorado at Boulder, Boulder, CO, United States; 4Biostatistics and Psychology, UCLA, Los Angeles, CA, United States Functional MRI (fMRI) is an important imaging modality to reveal altered function in neurodegenerative diseases. We hypothesize that functional changes in activation occur earlier and can be measured before structural degeneration is obvious. FMRI can potentially lead to an imaging marker for the early diagnosis of mild cognitive impairment (MCI) and furthermore may predict the development of Alzheimers disease (AD). In this work, we present fMRI results of 8 MCI and 8 normal subjects using different memory paradigms. 2295. Functional Connectivity in Resting State CBF Mapping in Postherpetic Neuralgia Jing Liu1, Yue Zhang2, XiaoYing Wang3, MinYi Du4, Jue Zhang2 1Department of Radiology, Peking University First Hospital , BeiJing, China; 2College of Engineering, Peking University, BeiJing, China; 3Department of Radiology, Peking University First Hospital, BeiJing, China; 4Department of Anaesthesiology, Peking University First Hospital, BeiJing, China Given the poor specificity and reproducibility of blood oxygenation level dependent(BOLD), we use cerebral blood flow for the first time to build resting-state networks of default mode both in patients suffering from postherpetic neuralgia and healthy subjects, and compare the two groups. The results of functional connectivity in healthy subjects showed that the areas activating were the same with the parts previously described in the literatures using BOLD. The results between-groups comparison showed that some parts were in strengthened correlation of posterior cingulate cortex in patients, such as anterior cingulated cortex and insula which are related to pain. Chunming Xie1, Liping Fu2, Lin Ma3, Wenjun Li1, Alex Cohen1, Zheng Yang2, Shi-Jiang Li1 1Medical College of Wisconsin, Milwaukee, WI, United States; 2Beijing Institute of Basic Medical Science, Beijing, China; 3Department of Radiology, The PLA General Hospital, Beijing, China The purpose of this study was to investigate the neuropsychological underpinnings of impulsive network on abstinent heroin addicts using resting-state functional connectivity method. Heroin subjects showed the higher impulsive scores and abnormal amygdala networks activity. The altered amygdala network strengths significantly correlated with impulsivity, and different correlation patterns were fund in heroin subjects relative to control subjects. This finding indicated the neural constructs of impulsive network was different in these two group subjects and altered amygdala network activity in heroin subjects makes a critical contribution to the impulsive dysfunction and represents the pathological damage underlying the impulsive control. 2297. Changes in Glutamate Levels After an FMRI Experiment Paul G. Mullins1, Niklas Ihssen1, David Linden1, Miles Cox1 1Psychology, Bangor University, Bangor, Gwynedd, United Kingdom MRS measures of brain chemistry are often considered static snapshots. We present MRS data showing an increase in Glutamate levels in the anterior cingulate cortex from baseline after a cognitive fMRI task. The biologic and methodologic implications of these findings are discussed. Markus Friedrich Hildenbrand1, Stephan Nauroth2, Xavier Helluy1, Philipp Moerchel3, Angelika Schmitt2, Klaus-Peter Lesch2 1Research Center Magnetic Resonance Bavaria (MRB), Wuerzburg, Germany; 2Department of Psychiatry, University of Wuerzburg, Germany; 3Department of Experimental Physics 5, University of Wuerzburg, Germany For psychiatric disorders being a worldwide strain to individuals and the health care systems and still being without comprehensive therapies, the mouse as model organism is a very promising research approach. Based on the development of a 17.6T ultra-high field BOLD-fMRI method for targeting the amygdala in the mouse brain, an access to serotonin mediated psychiatric diseases has been accomplished. By the usage of predator odor the activation of the amygdala shows a high sensitivity and specificity which yields a very good observation of the location and time devolution of the stimulus in the amygdala over a specified time period. Darragh Downey1, Gabriella Juhasz2, Shane McKie2, Karen Elizabeth Davies1, Emma Jane Thomas2, Diana Chase2, Rebecca Elliott2, John Francis William Deakin2, Ian Muir Anderson2, Stephen Ross Williams1 1Imaging Science and Biomedical Engineering, University of Manchester, Manchester, Lancashire, United Kingdom; 2Neuroscience and Psychiatry Unit, University of Manchester, Manchester, Lancashire, United Kingdom We investigated whether citalopram-challenge phMRI, as a probe of serotonin transporter function, would detect functional variants of the serotonin transporter gene and how this may influence normal serotonergic function. 42 normal volunteers underwent phMRI with intravenous 7.5mg citalopram. Homozygous Short/Short allele carriers had reduced BOLD responses bilaterally in the caudate, mid-cingulate gyrus and parietal cortex and increases in the superior frontal gyrus compared with the Long/Long carriers. The results offer the first direct evidence that the short and long variants of the 5HTT promoter region indeed influence synaptic 5HT function in the living human brain. 2300. Occupational Solvent Exposure and Working Memory Function David Matthew Carpenter1, Emily L. Eaves1, Cheuk Ying Tang1, Gudrun Lange2,3, Johnny Ng4, Nancy L. Fiedler5 1Radiology, Mount Sinai School of Medicine, New York, United States; 2Psychiatry, UMDNJ-New Jersey Medical School, Newark, NJ; 3Radiology, UMDNJ-New Jersey Medical School, West Orange, NJ, United States; 4Radiology, City Colege ofl New York, Bronx, NY, United States; 5Environmental and Occupational Medicine, UMDNJ- Robert Wood Johnson Medical School, Piscataway, NJ, United States In this report BOLD fMRI to investigate the functional deficits of subjects with long-term occupational solvent exposure. Subjects underwent fMRI while performing a Sternberg task and N-back working memory task. We used an exploratory voxel-wise and an ROI analysis to test the hypothesis that the occupationally exposed subjects show hypo-activation in regions associated with working memory when compared to a carefully matched control group. the results suggest that prolonged occupational solvent exposure is related to a decreased activation in regions associated with working memory. Peter Mannfolk1, Markus Nilsson1, Ronnie Wirestam1, Freddy Ståhlberg1,2, Peter Fransson3, Andreas Weibull4, Johan Olsrud1,5 1Dept. of Medical Radiation Physics, Lund University, Lund, Sweden; 2Dept. of Diagnostic Radiology, Lund University Hospital, Lund, Sweden; 3Department of Clinical Neuroscience, Stockholm Brain Institute, Karolinska Institute, Stockholm, Sweden; 4Dept. of Medical Radiation Physics, Lund University, Malmö, Sweden; 5Center for Medical Imaging and Physiology, Lund University Hospital, Lund, Sweden Clinical BOLD fMRI of children or in patients showing severe disease-related impairment can be difficult as active participation is required. Therefore, the possibility of using resting state data would be of great value. The aim of this study was to evaluate the test-retest reliability in detecting the intrinsic motor network from resting state data as compared to activation maps based on a bilateral finger tapping task. The test-retest reliability of resting state data was found to be comparable to what is seen for a typical task based fMRI-experiment within a subject. However, large differences between subjects were also found. Simon Robinson1, Alexander Geissler2, Siegfried Trattnig1, Roland Beisteiner2 1High Field MR Centre, Department of Radiology, Medical University of Vienna, Vienna, Austria; 2Clinical fMRI Study Group, Departments of Neurology, Neurosurgery, and Radiology, Medical University of Vienna, Austria We assess the effectiveness of a fast MGE sequence and postprocessing steps for fieldmapping with multichannel coils in correcting for EPI distortions in presurgical planning fMRI at 7T. Complex conjugate phase combination, unwrapping, denoising and fieldmap thresholding (for maximum achievable remapping) are described. Four patients underwent multiple runs of motor area localisation. Without distortion correction, primary foci for hand activation were mislocalised by 5-7mm, which could give rise to serious postoperative impairment of function. No residual distortions were observed after distortion correction, allowing fMRI results to be reliably registered to structural images and imported into neurosurgical planning systems. 2303. An Objective Approach to FMRI Assessment of Language Lateralization David F. Abbott1,2, Anthony B. Waites1,2, Graeme D. Jackson1,3 1Brain Research Institute, Florey Neuroscience Institutes (Austin), Melbourne, Victoria, Australia; 2Department of Medicine, The University of Melbourne, Melbourne, Victoria, Australia; 3Departments of Medicine & Radiology, The University of Melbourne, Melbourne, Victoria, Australia Language lateralization based on fMRI is often used in clinical neurological settings. With most conventional methods, the laterality determined can be dependent on the quality of a particular study and chosen statistical threshold. We present an objective threshold-independent method of assessing when individual patients have statistically atypical language lateralization. We illustrate the method using fMRI of verbal fluency in 34 healthy controls. One could also apply the method to other paradigms or regional assessments; for example the assessment of lateralisation of a different task, or to the assessment of anterior-posterior distribution rather than laterality. High Resolution Brain Imaging Hall B Tuesday 13:30-15:30 2304. Patch Structure in White Matter Detected by Microscopic MRI at High Field Strength Tie-Qiang Li1, M. Fukunaga2, K Shmueli12, S Dodd2, J H. Duyn2 1Department of Medical Physics, Karolinska University Hospital, S-141 86, Stockholm, Sweden; 2Laboratory of Functional and Molecular Imaging,, National Institute of Neurological Disorders and Stroke, National Institutes of Health,, United States T2*-weighted MRI at high magnetic field strength has recently been used to reveal cortical layer structures and white matter heterogeneity in vivo. Magnetic susceptibility differences have been widely thought to give rise to most of the contrast but the precise mechanisms underlying the contrast is still poorly understood. Here, we report an interesting finding from microscopic MRI and histological studies of white matter specimens of the human brain, which may provide further clues for better understanding of the mechanisms underlying the T2*-weighted contrast. Stephen J. Sawiak1,2, Guy B. Williams1, T Adrian Carpenter1, S A. Edgley3 1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom; 2Behavioural and Clinical Neurosciences Institute, University of Cambridge, Cambridge, United Kingdom; 3Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom Cerebellar agenesis is a condition where the cerebellum fails to develop normally. Here we present data from two individuals acquired post-mortem from brains extracted in the 1940s showing high resolution anatomical and structural data with MPRAGE and DTI sequences. 2306. Measuring Cortical Thickness of the Human Brain Using Ultra High Resolution Data Falk Lüsebrink1, Astrid Wollrab2 1RheinAhrCampus, Remagen, Germany; 2Biomedical Magnetic Resonance, Otto-von-Guericke-Universität, Magdeburg, Germany The analysis of the human cerebral cortex and the measurement of its thickness based on MRI data provide insight into normal brain development and neurodegenerative disorders. Accurate and reproducible results of the cortical thickness measurement are desired. In addition to data processing tools, the quality (i.e. resolution) of the imaging data is evaluated. We thus compare ultra high resolution data acquired at 7T with 3T data for measuring the cortical thickness of the human brain. 2307. Effect of Head Motion on the MRI Visibility of Cortical Layers in Human Primary Visual Cortex Jessica Schulz1, Miriam Wähnert1, Robert Trampel1, Robert Turner1 1Max-Planck-Institute for Human Cognitive and Brain Sciences, Leipzig, Germany There is increased interest in using ultra-high-field brain MRI to map intracortical structures. We simulated the effect on layer structure of small in-plane motions during data sampling, using 200 micron resolution ex vivo brain images. Such motions can easily introduce illusory structures, shown in images and cortical intensity profiles of human primary visual cortex, without and with motion corruption. Our simulations emphasize the crucial importance of appropriate motion correction of high resolution brain data.
2308. Sub-Millimeter Isotropic Ocular-Dominance Mapping at 7T Using 3D EPI Natalia Petridou1, Ben M. Harvey2, Serge O. Dumoulin2, S F.W. Neggers3, Tjerk Gutteling3, Peter Luijten1, Hans Hoogduin1 1UMC Utrecht, Utrecht, Netherlands; 2Psychology, Utrecht University, Utrecht, Netherlands; 3Rudolf Magnus Institute for Neuroscience, UMC Utrecht, Utrecht, Netherlands The advent of high fields has made it possible to reconstruct the functional organization of ocular-dominance columns in the human cortex with sub-millimeter in-plane (2D) resolution. However, 2D-based imaging techniques necessarily use anisotropic spatial resolution and are restricted to subjects that have relatively flat regions of cortex. Using 3D EPI with sub-millimeter isotropic resolution at 7T and a differential ocular stimulation we found alternating activation patterns in V1 which may relate to the expected ocular-dominance column distribution. This suggests that at 7T, 3D EPI can offer an avenue for sub-millimeter isotropic mapping not limited by the underlying anatomy. 2309. Optic Nerve Characterisation by Isotropic High-Resolution MRI Sandro Romanzetti1, Petra Stoerig2, Ana Maria Oros-Peusquens1, N. Jon Shah1,3 1Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Forschungszentrum Juelich, Juelich, Germany; 2Institut für Experimentelle Psychologie, Heinrich-Heine-Universität, Duesseldorf, Germany; 3Faculty of Medicine, Department of Neurology, RWTH Aachen, Aachen, Germany Many ophthalmological and neurological pathologies affect the optic nerve which provides the brain with retinal information. Revealing their manifestations with isotropic, high-resolution imaging of the optic nerve, the orbit and the chiasm may allow early and direct diagnosis of diseases that result in loss of visual function, partial or complete blindness. In this pilot study, we present isotropic, high-resolution optic nerve images which may be suitable for clinical applications. 2310. Detection of Cortical Layers Via Magnetization Transfer Imaging at 7T Olivier E. Mougin1, Alain Pitiot2, Penny A. Gowland1 1Sir Peter Mansfield Magnetic Resonance Centre, School of Physics & Astronomy,University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2School of Psychology, Institute of Neuroscience, Nottingham, Nottinghamshire, United Kingdom Variations in magnetization transfer (MT) ratio across the cortex have been detected using high resolution MT scans at 7T and are assumed to correspond to variations in myelination, and variations in MT corresponding to the stria of Gennari have been detected on MT maps. Tobias M. Lindig1,2, Sorin Breit1, Ludger Schöls1, Thomas Nägele, Uwe Klose2, Gunther Helms3 1Department of Neurology and Hertie-Institute for Clinical Brain Research, University Hospital Tuebingen, Tuebingen, Germany; 2Section of experimental MR of the CNS, Department of Diagnostic and Interventional Neuroradiology, University Hospital Tuebingen, Tuebingen, Germany; 3MR-Research in Neurology and Psychiatry, University Medical Center Goettingen, Goettingen, Germany The pedunculopontine nucleus (PPN) is a potential target for deep brain stimulation to address symptoms of gait freezing and postural instability in Parkinsons disease. Proton density-weighted (PD-w) MRI has been recommended to locate its position. Contrast and delineation of the PPN area in healthy subjects were improved by multi-echo 3D MRI at an increased resolution of 0.8 mm^3, and by using signal amplitude maps S0. These were calculated from a dual-angle FLASH protocol, thus eliminating the residual influence of T1 from the PD-w images. Usefulness for stereotactic planning was verified on two patients at 3T using a protocol of 4x4minutes. 2312. Ammons Horn Sclerosis Detected in Temporal Lobe Epilepsy with 7 T MRI Thomas R. Henry1, Marie Chupin2, Stéphane Lehéricy3, Kamil Ugurbil4, Frederick Ott5, Zhiyi Sha1, Pierre-Francois Van de Moortele5 1Neurology, University of Minnesota, Minneapolis, MN, United States; 2Universite Pierre et Marie Curie-Paris, Paris, France; 3Neuroradiology, Universite Pierre et Marie Curie-Paris, Paris, France; 4Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States; 5Radiology, University of Minnesota, Minneapolis, MN, United States Increased contrast and spatial resolution at 7 T permitted the reliable detection of internal architecture of the hippocampal formation. Submillimetric T2w images at 7 T consistently resolved the continuous white matter band, which separates deep portions of CA1-3 from CA4 and the dentate hilus. The resulting accuracy permitted intrahippocampal (subregional) volumetry. These preliminary results strongly support expectations that brain imaging at very high magnetic field may allow for a more accurate patient classification based on qualitative and quantitative information that is difficult or impossible to collect reliably at lower field. 2313. In Vivo Imaging of Human Hippocampal Subfields at 7 Tesla Caitlin Judith Hardy1, Vasthie Prudent, Songtao Liu, Graham Wiggins, Dolores Malaspina2, Oded Gonen 1Radiology, NYU School of Medicine, New York, NY, United States; 2Psychiatry, NYU School of Medicine Using a combination of 7 T field, B0-shim, high count receive-coil arrays and heavy T2* weighting we were able to depict hippocampal subfields down to 100 micron in 10/10 young adults in a clinically acceptable time of 14 minutes. Christian Wasserthal1, Karin Engel2, Jörg Stadler1, Bruce Fishl3,4, Patricia Morosan5, Andre Brechmann1 1Special-Lab Non-Invasive Brain Imaging, Leibniz-Institute for Neurobiology, Magdeburg, Germany; 2Department of Simulation and Graphics, Otto-von-Guericke University of Magdeburg, Germany; 3Department of Radiology, Harvard Medical School, Charlestown, MA, United States; 4Computer Science and AI Lab, Massachusetts Institute of Technology, Cambridge, MA, United States; 5Institute of Medicine, Research Center Jülich, Germany In the visual system the primary cortex area can robustly be identified by retinotopic mapping. In the auditory modality, a routine method to delineate the primary auditory cortex (PAC) area in individual human subjects is not available. We developed a method to anatomically identify the PAC area on the basis of myelin content in single subjects by creating an artificial contrast using conventional T1 and T2 weighted imaging at 3 Tesla. Results show a region on the medial two thirds of Heschls gyrus that is very consistent to the probability map of the PAC defined in post-mortem brains. Marcus Belke1, David H. Salat2, Enno Wehrmann1, Katja Menzler1, Ulrike Lengler3, Wolfgang H. Oertel1, Felix Rosenow1, Karsten Krakow3, Susanne Knake1 1Department of Neurology, Philipps-University Marburg, Marburg, Germany; 2Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Boston, MA, United States; 3Brain Imaging Center Frankfurt, University of Frankfurt, Frankfurt, Germany We investigated association between total intracranial volume (TIV) and the volume of several cortical, subcortical and white matter regions. After an automated parcellation of the brain, a slope was calculated, representing the proportional volume of each structure relative to the TIV. Cortical regions were particularly associated with TIV. The greatest slope of the subcortical regions was found for the brainstem. In a second test gender differences were investigated. Large differences were found between men and women when uncorrected volumes were compared. After correction for the influence of the TIV, no gender differences were found in any of the investigated regions. Enrico Arkink1, Nicole Schmitz1,2, Guus Schoonman3, Jorien van Vliet3,4, Gisela Terwindt3, Mark van Buchem1, Michel Ferrari3, Mark Kruit1 1Radiology, Leiden University Medical Center, Leiden, Netherlands; 2Psychiatry, Amsterdam Medical Center, Amsterdam, Netherlands; 3Neurology, Leiden University Medical Center, Leiden, Netherlands; 4Neurology, Medisch Centrum Haaglanden, Den Haag, Netherlands Trigeminal autonomic cephalalgias include cluster headache, paroxysmal hemicrania and SUNCT. An earlier voxel-based morphometry (VBM) study pointed at the posterior inferior hypothalamus to be involved in CH, but results were never reproduced. In the current study we used state of the art whole-brain and regional VBM, and manual segmentation of the hypothalamus, in analyzing the brains of 151 subjects with TACs (n=70), migraine patients (n=33) and controls (n=48). We found the anterior part (but not the posterior part) of the hypothalamus, including the suprachiasmatic nucleus (the biological clock), to be larger in TACs compared to migraineurs and controls. Our results seem to be specific for TACs, and question the validity and/or relevance of the earlier finding, including its role in deep brain stimulation as treatment for intractable cluster headaches. 2317. Clinically-Driven Fast and High-Resolution Mapping of T1, M0, and B1 with Whole Brain Coverage Mohammad Sabati1, Baranavasi Govindaraju1, Andrew Maudsley1 1Radiology, University of Miami, Miami, FL, United States Quantitative MR techniques, such as accurate mapping of the longitudinal relaxation time and water content, have become more important in neurological research. The current T1 mapping methods are generally lengthy and not adequate in a clinical environment. Also, further acquisitions are usually required to obtain the brain tissue water content. Several factors, including RF field inhomogeneities and low SNR impair the accuracy of these methods. In this study, we present a modified two-acquisition SPGR method for simultaneous B1, T1, and M0 mapping with a 1-mm isotropic spatial resolution that covers the entire human brain in a clinically acceptable time. 2318. Orientation Selectivity of Individual Voxels in Early Visual Areas Using 7 Tesla Geoffrey Ghose1,2, Cheryl Olman, 2,3, Kamil Ugurbil2, Essa Yacoub2 1Neuroscience, University of Minnesota, Minneapolis, MN, United States; 2CMRR, University of Minnesota, Minneapolis, MN, United States; 3Psychology, University of Minnesota, Minneapolis, MN, United States Using 1.5 mm isotropic GE imaging of BOLD activation to a continuously rotating stimulus, we find individual voxels with significant orientation selectivity in human visual areas V1, V2, and V3. 2319. Layer-Specific MRI of the Rat Retina with Intraocular Injection of Gadolinium-DTPA Eric Raymond Muir1,2, Timothy Q. Duong2 1Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States; 2Research Imaging Institute, Ophthalmology/Radiology, UT Health Science Center San Antonio, San Antonio, TX, United States The retina can be divided into seven cellular and synaptic layers. It has been shown that intraocular injection of manganese enhances contrast in the rat retina, revealing 7 layers with MRI. Gadolinium-DTPA is a T1 shortening contrast agent like manganese, but the localization of the two within in a tissue could be expected to be to differ, potentially leading to different layer-specific enhancement. In this study we used intraocular injection of gadolinium to provide unique layer enhancement in the rat retina. Gadolinium-enhanced MRI clearly resolved six retinal layers at 25x25 µm. 2320. Contrast at Ultra-High Field: Relaxation Times in the Rat Brain at 16.4 T Rolf Pohmann1 1Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany Knowledge of the relaxation times is not only necessary for sequence optimization; it may also be decisive to judge the advantages for ultra-high field MRI. Here, T1, T2 and T2* in the rat brain were measured at 16.4 T with a spatial resolution of 180 µm inplane. The relaxation times were quantified with high accuracy for 20 anatomical structures and maps were generated to display the spatial distribution of the relaxation times over the brain. Kara E. Yopak1, Lawrence R. Frank1 1Center for Scientific Computation in Imaging, UCSD, La Jolla, CA, United States The study of species with unique behavioral and morphological specializations is critical when teasing apart evolutionary trends, yet becomes difficult, as often these species are extremely rare and invasive methodologies are impractical. This paper examines the use of MRI to obtain high-resolution image data in an important but damaged brain specimen of the whale shark, Rhincodon typus, wherein digital reconstruction allowed for non-invasive quantification of its brain organization. We will discuss the effectiveness of MRI as investigative tool for non-invasive visualization and quantification of the internal anatomy of fishes. 2322. Detection of Amyloid-Beta Plaques Using Phase Imaging at 9.4 Tesla Wen-Tung Wang1, In-Young Choi1,2, Jieun Kim1, Sang-Pil Lee1 1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States; 2Neurology, Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, United States Magnetic resonance imaging is the only modality that can provide sufficient spatial resolution and image contrast to visualize Alzheimers amyloid plaques noninvasively. Previously Alzheimers amyloid plaques have been visualized in images acquired using spin-echo and gradient echo sequences at 7 T and 9.4 T. At high fields, it has been reported that the increased susceptibility-related contrast resulted in additional anatomical information, such as delineation of veins and iron-rich regions in human brain. In this study, we show that the susceptibility-induced contrast in gradient-echo phase images can improve detection of amyloid plaques. Benjamin Marty1, Céline Giraudeau1, Julien Flament1, Sidi Mohamed Ahmed Ghaly1, Franck Lethimonnier1, Fawzi Boumezbeur1, Julien Valette1, Sébastien Mériaux1 1CEA/DSV/I2BM/Neurospin, Gif-Sur-Yvette, France Amyloid plaques are a marker of Alzheimer's disease which are traditionally detected as hypointense signals on T2*-weighted images due to the presence of iron. This study proposes a comparison between the images of an ex vivo APP/PS1 mouse brain obtained using a conventional T2* gradient echo sequence and a zoom adiabatic T2 spin echo sequence. This comparison, based on the ability of both sequences to allow successful plaques detection using an automatic home-made procedure, reveals that T2 contrast allows resolving amyloid plaques with a better specificity than T2* contrast, which is disturbed by the hypointense signals coming from blood vessels. 2324. Anatomical Phenotyping of Rett Syndrome in the Mouse Jacob Ellegood1, Jason P. Lerch1, R Mark Henkelman1 1Mouse Imaging Centre, Hospital for Sick Children, Toronto, Ontario, Canada Rett Syndrome is an X-linked disorder, which primarily affects females, and is caused by mutations to the Mecp2 gene. A commonly used mouse model of RTT involves a truncation of the Mecp2 gene at codon 308. The purpose of this study was to examine the volume changes in the Mecp2308 Rett syndrome mouse model with high resolution MRI. Volume changes were found in many regions, for example, significant decreases were found in the cerebral cortex as well as increases in the cerebellar cortex and ventricles. Porzia Totaro1, Eytan Raz, Gian Marco Contessa, Francesca Tona, Giovanni Fabbrini, Alfredo Berardelli, Carlo Colosimo, Luigi Bozzao, patrizia pantano2 1Department of Neurological Sciences, Sapienza University of Rome, Rome, Italy; 2Sapienza University of Rome, Rome, Italy, Italy A transversal and longitudinal MRI study in patients with cervical dystonia using voxel-wise comparison of the local Gray Matter concentration.
2326. MRI of the Lumbar Spine at 7 Tesla in Healthy Volunteers and a Patient with Spina Bifida Astrid Ellen Grams1,2, Oliver Kraff, 12, Lale Umutlu1,2, Stefan Maderwald, 12, Philipp Dammann, 2,3, Mark E. Ladd, 12, Michael Forsting1,2, Elke Ruth Gizewski1,2 1Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, NRW, Germany; 2Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Hospital Essen, Essen, NRW, Germany; 3Department of Neurosurgery, University Hospital Essen, Essen, NRW, Germany In the present study the feasibility of imaging of the lumbar spine and its adjacent structures under healthy and under pathological conditions at 7 Tesla was investigated. A combination of a 3D-CISS and a 3D-VIBE sequence comprehended imaging of the vertebrae, the intervertebral discs, the bony neural foramina, the facet joints, the dural sac and the intraspinal portions of the spinal nerves. 2327. Voxel-Based Morphometric Analysis of Gray and White Matter in Perinatally HIV-Infected Youth Manoj Kumar Sarma1, Rajakumar Nagarajan1, Michael Albert Thomas1, Judy Hayes2, Jaime Deville3, Karin Nielsen3, David Michalik4, Whitney B. Pope1, Margaret A. Keller2 1Radiological Sciences, UCLA, Los Angeles, CA, United States; 2Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, United States; 3Pediatrics, UCLA, Los Angeles, CA, United States; 4Millers Childrens Hospital, Long Beach, CA, United States Voxel-based morphometry was used to compare both gray and white matter volume in perinatally human immunodeficiency virus (HIV)-infected youth versus healthy controls. HIV patients had reduced gray matter volume in the bilateral caudate nucleus, left parietal lobe, but an increase of gray matter volume in the frontal lobe, posterior temporal lobe, and parietal lobe. Striking white matter volume reductions were found in the temporal lobe, pons, right pre-frontal area, corpus callosum and the junction of the thalamus and mid brain. These findings suggest the sensitivity of VBM in evaluating GM and WM abnormalities in perinatally HIV-infected youth. 2328. The Effects of Voxel Size and Image Smoothing on R2* Measurements of the Human Brain Christian Denk1, Alexander Rauscher1 1UBC MRI Research Centre, University of British Columbia, Vancouver, BC, Canada Quantitative imaging of the R2* relaxation rate employing multiple echoes can be used to assess blood oxygenation and iron content in neural structures. However, R2* is not a strictly intrinsic tissue property, as it also depends on the spatial relationship between voxel geometry and background field inhomogeneities. These background field inhomogeneities cause additional signal decay. To investigate the influence of spatial resolution and smoothing on R2* values, we acquired images with high spatial resolution and applied spatial smoothing to the complex data, which simulates acquisition at lower spatial resolution, and to the magnitude data. We found that both changes in spatial resolution and spatial smoothing of magnitude of high resolution data leads to strong changes in R2*, which suggests that R2* values should be interpreted in the light of data acquisition parameters as well as data smoothing. 2329. Direct Visualization of Surgical DBS Targets Using High-Field (7T) MRI Noam Harel1, Essa Yacoub2, Kamil Ugurbil2, Aviva Abosch3 1Radiology, University of Minnesota, Minneapolis, MN, United States; 2Radiology , University of Minnesota, Minneapolis, MN, United States; 3Neurosurgery, University of Minnesota, Minneapolis, MN, United States Deep brain stimulation (DBS), a surgical treatment involving the implantation of an electrode in the brain, is used for the treatment of patients with movement disorders. The success of this surgical technique is critically dependent on precise placement of the DBS electrode into the target structure. However, current clinical imaging methods lack the sensitivity for resolving and visualizing of the DBS target. Here, using a combination of high magnetic field (7T) with susceptibility-weighted contrast resulted in a dramatically improved ability to identify and delineate anatomical architecture of deep brain structures that are FDA-approved DBS targets. 2330. Human T2* and Phase Imaging at 9.4 T Juliane Sabine Budde1, Gunamony Shajan1, Jens Hoffmann1, Frank Muehlbauer1, Kāmil Ugurbil2, Rolf Pohmann1 1Max Planck Institute for Biological Cybernetics, Tuebingen, Germany; 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, United States Ultra-high static magnetic field causes higher susceptibility effects which yield shorter T2* values and larger variations of the image phase. In this work, we acquired highly detailed T2* maps showing internal structures. Mean T2* values for GM were estimated as 28ms±6ms and 20ms±4ms for WM. Phase images were post-processed to yield images with high tissue contrast between grey and white matter throughout the brain at a resolution of 200µm x 200µm x 1mm. Signal gain at ultra-high field allows for high resolution surface phase images of 130µm x 130µm in-plane resolution. In these, differences within grey matter are visible. Anja Gwendolyn van der Kolk1, Jaco JM Zwanenburg1, Geert Jan Biessels2, Fredy Visser1,3, Peter R. Luijten1, Jeroen Hendrikse1 1Department of Radiology, University Medical Center, Utrecht, Netherlands; 2Department of Neurology, University Medical Center, Utrecht, Netherlands; 3Philips Healthcare, Best, Netherlands Seven patients with clinically and standard imaging-based proven ischemic or hemorrhagic stroke were scanned with magnetization prepared 3D FLAIR, combined time-of-flight inflow and multi-echo fast field echo (meFFE), T1 3D TFE, and DTI. 7.0 Tesla results were comparable to results of similar 1.5 Tesla sequences, but with better resolution and in 3 out of 7 patients additional information regarding underlying pathology. Furthermore, meFFE with 3 echoes was valuable in identification of microbleeds, microinfarcts and thrombus. General Brain Imaging: Technique Development Hall B Wednesday 13:30-15:30 2332. Multicontrast 3D Structural Imaging to Improve Automatic Brain Extraction and Segmentation Bradley P. Sutton1,2, Anh Tu Van3 1Bioengineering, University of Illinois, Urbana, IL, United States; 2Beckman Institute, University of Illinois, Urbana, IL, United States; 3Electrical and Computer Engineering, University of Illinois, Urbana, IL, United States Currently many structural neuroimaging studies rely only on a T1-weighted image for brain extraction. Additional image contrast like T2 may improve the performance of the automatic brain extraction procedure. In this work, a previously proposed multiparametric 3D structural imaging sequence that provides several volumes with varying contrast in a multi-echo acquisition is used to assist in automatic brain segmentation. Two 3D volumes (one T1-weighted and one T2-weighted) with 1.2 mm isotropic resolution and a low resolution 3D field map were obtained simultaneously within 6.5 minutes. Improvement in brain extraction utilizing the additional contrast was observed. 2333. PROPELLER Using Parallel Imaging with Across Blade Calibration for T1 FLAIR James H. Holmes1, Philip J. Beatty2, Howard A. Rowley3,4, Zhiqiang Li5, Ajeetkumar Gaddipati6, Xiaoli Zhao6, Reed F. Busse1, Jean H. Brittain1 1Applied Science Laboratory, GE Healthcare, Madison, WI, United States; 2Applied Science Laboratory, GE Healthcare, Menlo Park, CA; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States; 4Neurological Surgery, University of Wisconsin-Madison, Madison, WI, United States; 5GE Healthcare, Phoenix, AZ; 6GE Healthcare, Waukesha, WI, United States A novel parallel imaging technique for PROPELLER that utilizes external calibration data as well as a small amount of internal calibration data per blade is demonstrated for T1 FLAIR imaging. Short echo trains, which are optimal for T1 imaging, are maintained while the effective blade width is increased by reducing the number of internal calibration lines. Wider blades enable motion to be detected and corrected more reliably, improving robustness in uncooperative patients. The method is validated in studies of volunteers instructed to move their head during the acquisition. shiun-ying Ju1, Yu-Wei Tang1, Teng-Yi Huang1, Hsu-Hsia Peng2 1Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; 2Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua university, Hsinchu, Taiwan The MR flow quantification of the vessels can be used to evaluate the response of the vessel-related surgeries. However, for the conventional longitudinal studies of blood flow, manual slice selection in different days can cause measurement variation and thus degrade the accuracy of evaluation. In our study, in order to solve this problem, an automatic slice positioning method combined with previously implemented automatic ROI selection method were proposed to reduce the inter-scan variation. Furthermore, GPU-accelerated computation was applied to speed up the image registration. The flow variation of the human study was reported. 2335. MRI Estimation of Global Brain Oxygen Consumption Rate Varsha Jain1, Michael Langham1, Felix Wehrli1 1University of Pennsylvania, Philadelphia, PA, United States The human brain is extremely sensitive and vulnerable to even small alterations in oxygen supply, making a measure for assessing global cerebral metabolic rate of oxygen consumption (CMRO2) very important. We propose a method for estimating CMRO2 by simultaneous quantification of oxygen saturation by MR oximetry and cerebral blood flow by phase-contrast MRI in the major vessels draining (superior sagittal sinus) and feeding the brain (internal carotid and vertebral arteries), respectively. Our results demonstrate that the proposed technique is robust and reproducible, yielding temporally stable measurements at a temporal resolution 30 seconds. Jingfei Ma1, Ken-Pin Hwang2, Ashok Kumar3, Lawrence Ginsberg3 1Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX, United States; 2Applied Science Lab, GE Healthcare Technologies, Houston, TX, United States; 3Department of Diagnostic Radiology, University of Texas MD Anderson Cancer Center, Houston, TX, United States Inclusion of fat suppress (FS) pulses in a spin echo acquisition substantially reduces scan efficiency. At 3 Tesla, the incidental magnetization transfer and dielectric effects from the FS pulses also degrade the image contrast and image uniformity. In this study, we developed a spin echo two-point Dixon technique for fat-suppressed T1-weighted imaging. In comparison to the conventional spin echo with FS pulses, we demonstrated in vivo that the new technique was 40% more efficient and had much better image contrast, better FS and overall image uniformity for fat-suppressed T1-weighted imaging of head & neck at 3 Tesla. Hsiao-Wei Peng1, Chao-Chun Lin2,3, Yi-Jui Liu1,4, Chien-Kuo Chen1, Kuo-Fang Shao4, Wu-Chung Shen2,5, Hing-Chiu Chang6,7 1Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan, Taiwan; 2Department of Radiology, China Medical University Hospital, Taichung, Taiwan; 3Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; 4Master's Program in Biomedical Informatics and Biomedical Engineering, Feng Chia University, Taichun, Taiwan; 5School of Medicine, China Medical University, Taichung, Taiwan; 6Applied Science Laboratory, GE Healthcare Taiwan, Taipei, Taiwan; 7Institute of Biomedical Electronics & Bioinformatics, National Taiwan University We aimed to design a head holder for calculation the susceptibility through multiple orientation sampling (COSMOS). Different brain tissues with different susceptibility result in the changes of focal magnetic fileds. Quantitative susceptibility imaging of brain are obtained by measurement of the focal magnetic field changes.. It is a promising approach for exploring various brain pathological conditions. For clinical application, the challenging problem is to rotate the head of patient along the Y axis only and fix the head in the degree through the MR scan. Our results show great control of the rotation in three axes with the facilitation of head holder. 2338. A Study Specific Brain Template in MNI Space for an Aged Population with Aortic Stenosis Ping Wang1, Elizabeth Strambrook2, Thomas Floyd3 1Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Anesthesiology & Critical Care, University of Pennsylvania, Philadelphia, PA, United States; 3Anesthesiology & Critical Care, and Neurology, University of Pennsylvania, Philadelphia, PA, United States The MNI standard template is ideal for healthy subjects. To improve the accuracy of normalization and the further analysis (such as statistical analysis), we created a study specific template in MNI space for an aged population with mild to critical aortic stenosis. This study specific template is approximately in MNI template space, but accommodates some characteristics of this particular study population, especially incorporating the increased ventricular volume. 2339. Use of Opposed Shim Currents for Infold Reduction on a UHF MRI System with Head Gradient Christopher John Wiggins1, Marion Caillat1, Denis Le Bihan1, Franz Schmitt2, Eva Eberlein2 1CEA/NeuroSpin, Gif-Sur-Yvette cedex, France; 2Siemens AG, Healthcare Sector Imaging & IT Division, Magnetic Resonance, Erlangen, Germany The use of a head gradient set within a wholebody magnet can lead to significant artifacts. Signal arising from the shoulders is encoded in such a way that it aliases into the main image. Such artifacts are particularly pronounced at higher field, where B1 effects cause the sensitive region of volume coils to extend out into the chest and shoulder region. Previous approaches have tried to diminish the RF penetration in this area (through the use of RF shielding materials) or to disrupt the local field through using ferromagnetic material shown into a jacket that the subject wears. This study shows that with the use of both the wholebody and head gradient shim sets the signal from the shoulders could be dephased without affecting the signal from the head itself. Pankit Parikh1, Gurpreet Singh Sandhu1,2, Kristine A. Blackham1, Michael D. Coffey1, Daniel P. Hsu1, John A. Jesberger2, Kecheng Liu3, Mark A. Griswold1,4, Jeffrey L. Sunshine1,2 1Radiology, University Hospitals of Cleveland, Case Western Reserve University, Cleveland, OH, United States; 2Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States; 3Siemens Healthcare, Malvern, PA, United States; 4Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States Phased-array coils with increasing number of array elements have been developed and employed for clinical MR imaging. A phased-array head coil with 32 array elements provides quantitatively better brain images as compared to commercially available head coil with lower number of array elements. In this study, we investigate if application of this coil would improve the anatomic and pathologic analysis from the resultant brain images by qualitatively comparing MR images obtained using this coil with those obtained using a commercially available phased-array head coil with 12 array elements. 2341. Looking at Magnetization Exchange in Human White Matter Structures in Vivo Saeed Kalantari1, Cornelia Laule2, Thorarin Bjarnason3, Alex MacKay1,2 1Department of Physics and Astronomy, University of British Columbia Hospital, Vancouver, BC, Canada; 2Department of Radiology, University of British Columbia Hospital, Vancouver, BC, Canada; 3Department of Electrical and Computer Engineering, University of Calgary The objective of this study was to measure the cross relaxation exchange time between the myelin water and intra/extracellular water pools in healthy human white matter in vivo. Five different white matter structures were investigated. Bloch equations were solved analytically and cross relaxation exchange times were extracted. Due to the ambiguity in the literature on spin-lattice relaxation times in white matter, three T1 scenarios were developed. The extracted cross relaxation times were then used to estimate the exchange corrections for myelin water fraction (MWF) measurements. The choice of T1 scenario had a significant effect on cross relaxation times and consequently on MWF corrections. Andrew T. Curtis1,2, Lauren E. Villemaire2, Kyle M. Gilbert1, Ravi S. Menon1,2 1Centre for Functional and Metabolic Mapping, Robarts Research Institute, London, Ontario, Canada; 2Medical Biophysics, The University of Western Ontario, London, Ontario, Canada An agarose gel and saline solution phantom was developed to mimic properties of the human brain at 7T. This design provides many parameters matched to the behaviour seen in vivo including: grey matter/white matter contrast for sequence development, matched B1+ interference (RF wavelength) behaviour, and coil loading effects. Xia Li1,2, Ann Choe, 2,3, Yurui Gao3,4, Iwona Stepniewska3, Adam Anderson3,4 1Radiology, Vanderbilt University, Nashville, TN, United States; 2Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 3Biomedical Engineering, Vanderbilt University; 4Institute of Imaging Science,, Vanderbilt University, Nashville, TN, United States The light microscopy images have a high spatial resolution and are usually co-registered to the corresponding MR images in order to make the comparison. However, there are artifacts, such as tearing, deformation, or disappearance of tissue fragments, in the stained slices. Those artifacts make the registration among MR, blockface, and light images more difficult. In this study, two image post-processing techniques are introduced, which can provide a better initialization to the nonrigid registration algorithm. General Neuroimaging Hall B Thursday 13:30-15:30 Wei Yu1, Li Dong, 12, Lu Zhou1, Dan Hipper2, Marina Fergurson2, Guangrui Liu1, Dean Shibata2, Chun Yuan2, Zhaoqi Zhang1 1Beijing Anzhen Hospital, Capital Medical University, Beijing, China; 2University of Washington, Seattle, WA, United States We determined the inter-reader reproducibility in the assessment of carotid territory brain lesions. In a carotid study, two reviewers reviewed brain images of 134 hemispheres from 67 subjects independently. The inter-reader agreement was substantial for the lesion presence (κ = 0.67; 0.54-0.80) and the lesion size (κ = 0.75; 0.60-0.92), and there was complete agreement (κ = 1.0) for age. Some disagreements on the presence or absence of lesions may be due to their location near the boundary of the carotid territory. It is important to point out small old lesions were the primary factor that reduced reproducibility. Xiaodong Zhang1, Chao He2, Lihong Hui3, Xiaoying Wang, 1,3, Sheng Xie3, Jiangxi Xiao3, Hongyu An4, Jue Zhang1,2, Jing Fang1,2 1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; 2College of Engineering, Peking University, Beijing, China; 3Dept.of Radiology, Peking University First Hospital, Beijing, China; 4Dept. of Radiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States Cerebral oxygen extraction factor (OEF) provides critically important information to assess the brain oxygen metabolism in both normal and disease states. It has been reported that the OEF could be evaluated for healthy human volunteers using MRI. In this study, a based gradient echo sampling of the spin echo (GESSE) sequence implemented on GE 3.0T scanner to evaluate the cerebral OEF distribution of rabbits before and after carotid artery occlusion operation. Our study demonstrated a consistent and significant increase of OEF in rabbits post carotid artery occlusion, suggesting that this MR based method can be utilized to detect pathophysiological changes in cerebral oxygenation. 2346. Myelin Water Imaging of Children with Diverse Reading Ability Eugene Yip1, Pauline Low2, Burkhard Mädler, 1,3, Catherine Lebel4, Christian Beaulieu4, Linda Siegel2, Alex Mackay1 1Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada; 2Department of Education and Counselling Psychology, and Special Education, University of British Columbia, Vancouver, British Columbia, Canada; 3Philips Medical Systems; 4Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada Magnetic resonance imaging provides a mean to non-invasively investigate the neurological cause of dyslexia, a learning disability that affects ones ability to read despite adequate intelligence. Myelin water imaging, based on calculating the myelin water fraction from multi-echo T2 relaxation curves, can be used to quantitatively assess white matter. In this study, myelin water imaging and cognitive and reading assessments were performed on children with a wide range of reading ability in order to investigate the relationship between dyslexia and white matter development in the brain. Zhifeng Kou1, Robin Hanks, Scott Millis, Randall Benson, Ramtilak Gattu, E Mark Haacke1 1Radiology, Wayne State University School of Medicine, Detroit, MI, United States There is no treatment of TBI partially due to the current clinical classification system cannot effectively identify the pathoanatomical information of the brain. We propose that a synergistic use of multi-imaging techniques may capture much of the heterogeneity and complexity of brain injury in individual patients therefore result in improved accuracy and detail in prognostic models and improved efficiency of clinical trials. In this study, we report our preliminary observations regarding the synergistic use of these three MRI techniques in an improved characterization of TBI. Alexander Christian Bunck1, Wolfram Schwindt1, Jan-Robert Kröger1, Alena Jüttner1, Angela Brentrup2, Barbara Fiedler3, Gerard Crelier4, Walter Heindel1, David Maintz1, Thomas Niederstadt1 1Department of Clinical Radiology, University hospital of Muenster, Muenster, Germany; 2Department of Neurosurgery, University hospital of Muenster, Muenster, Germany; 3Department of Paediatrics, University hospital of Muenster, Muenster, Germany; 4Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland Time resolved 3D-phase contrast imaging allows to assess cerebrospinal fluid pulsation at the craniocervical junction and cervical spine. Using state-of-the-art visualization techniques it helps to identify and differentiate between pathological and physiological cerebrospinal fluid flow pattern. As such it may add valuable information for the analysis of pathologies associated with altered cerebrospinal fluid flow like in Chiari malformations and may promote a better understanding of the underlying pathophysiology of these diseases. 2349. Differentiating Haematoma with the R2' Relaxation Rate Gopal Varma1, Prakash Saha2, Matt Waltham2, Stephen Keevil1,3, Alberto Smith2, Tobias Schaeffter1 1Imaging Sciences, King's College London, London, United Kingdom; 2Academic Department of Surgery, King's College London, London, United Kingdom; 3Medical Physics, Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom Subdural haematoma (SDH) is an emergency when acute, and management is often guided by imaging. Distinguishing between the different phases of SDH may be possible by the presence and position of methaemoglobin. In this study, we create an in vitro system of SDH and examine the relationship between intra- and extracellular methaemoglobin at various concentrations, using R2, R2* and R2ā parameters. R2ā relaxation rate appears to be the most sensitive marker of methaemoglobin concentration and can readily differentiate between when it is intra- or extracellular. This parameter could therefore be used to stage the phase of SDH. Anja Gwendolyn van der Kolk1, Gert Jan de Borst2, Anne G. den Hartog2, M Eline Kooi3, Willem PThM Mali1, Jeroen Hendrikse1 1Department of Radiology, University Medical Center, Utrecht, Netherlands; 2Department of Vascular Surgery, University Medical Center, Utrecht, Netherlands; 3Department of Radiology, University Medical Center, Maastricht, Netherlands The carotid MR hyperintense (vulnerable) plaque is associated with a higher morbidity and mortality. We investigated the prevalence of this plaque and its clinical correlates on T1-weighted turbo-field echo (T1w-TFE) MRI in patients with ischemic symptoms and varying degrees of stenosis. 153 patients with TIA or ischemic infarct were retrospectively examined. 18% showed one or more hyperintense plaques. Half of all hyperintense plaques occurred in symptomatic patients with either 0-69% stenosis or occlusion; more than ⅓ of patients with 50-69% stenosis presented with this plaque. This subgroup of patients could in future possibly benefit from aggressive medicinal therapy or revascularization. Karin Shmueli1, Ruth O'Gorman2,3, David Lythgoe4, Michael Samuel5, Richard Selway6, Keyoumars Ashkan6, Jozef Jarosz2 1Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States; 2Department of Neuroradiology, King's College Hospital, London, United Kingdom; 3MR-Zentrum, University Childrens Hospital, Zurich, Switzerland; 4Centre for Neuroimaging Sciences, Institute of Psychiatry, King's College London, United Kingdom; 5Department of Neurology, King's College Hospital, London, United Kingdom; 6Department of Neurosurgery, King's College Hospital, London, United Kingdom Susceptibility-Weighted Imaging (SWI) improves the visibility of target structures (globus pallidus (GP) and subthalamic nucleus (STN)) for deep brain stimulation (DBS). However, because phase contrast is non-local and orientation dependent, SWI contains artifacts that may result in targeting errors. Susceptibility maps, which have shown promise for overcoming such artifacts, were calculated from clinical 1.5-T phase data acquired at a single orientation. 2-mm shifts in the superior borders of the red nuclei and GP in the SWI relative to the susceptibility maps were observed in several volunteers and DBS patients showing that susceptibility mapping may help reduce SWI targeting errors. 2352. Aqueduct CSF Flow Measured Objectively with PC-MRI Anders Wåhlin1, Khalid Ambarki1, Anders Garpebring1, Jan Malm2, Richard Birgander1, Anders Eklund1 1Radiation Sciences, Umeå University Hospital, Umeå, Västerbotten, Sweden; 2Clinical Neuroscience, Umeå University Hospital, Umeå, Västerbotten, Sweden Aqueductal cerebrospinal fluid flow, measured with motion sensitive phase contrast MRI, is subject to typical imperfections in flow imaging such as partial volume effects and difficulties in lumen delineation. In this study we abandoned graphically represented vessel delineations. Instead we used complex data generated by the PC-MRI in a method with the potential of objective and absolute measurement of CSF velocity and area, without restrictions by matrix resolution. We compared the complex value methodology with conventional manual segmentation for the determination of aqueduct CSF stroke volume in a group of 42 healthy elderly. Amanda Kathleen Wake1, John C. Gore1, J. Christopher Gatenby1 1Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States In this study high field MR and phase contrast (PCMR) data were used to construct a subject-specific model of flow in the vertebro-basilar system. Wall shear stress (WSS) data from the model yield insight into artery bypass graft design. Animal Models of Brain Disease Hall B Monday 14:00-16:00 2354. Decreased ADC Precedes Cellular Swelling in N-Methyl-D-Aspartate (NMDA) Treated Mouse Retina Chia-Wen Chiang1, Junjie Chen2, Sheng-Kwei Song3 1Chemistry, Washington University in St. Louis, Saint Louis, MO, United States; 2Medicine, Washington University in St. Louis, Saint Louis, MO, United States; 3Radiology, Washington University in St. Louis, Saint Louis, MO, United States Apparent diffusion coefficient (ADC) is a widely used neuronal injury marker for early detection of various brain disorders. In the current study, we investigated the timing of decreased ADC vs. the detectable tissue swelling resulting from N-methyl-D-aspartate (NMDA) induced cytotoxic edema in mouse retina in vivo. Results suggest that decreased ADC is a biomarker of cytotoxic edema providing an early measure of retinal excitotoxic injury before detectable retinal swelling. Sakthivel Sekar1, Marleen Verhoye1, Johan Van Audekerke1, Koen Tahon2, Koen Wuyts3, Claire Mackie3, Michele Giugliano2, Thomas Steckler3, Annemie Van Der Linden1 1Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium; 2Theoritical Neurobiology, University of Antwerp, Antwerp, Belgium; 3Johnson & Johnson Pharmaceuticals Research & Development, Beerse, Belgium The present study reports on the acute and sub-chronic neuronal effects of the NMDA antagonist memantine on the rat brain measured as BOLD (blood oxygenation level dependent) contrast changes in a pharmacological magnetic resonance imaging (phMRI) study. Corroborative investigations include recording the spontaneous local field potential (LFP) activity in key brain regions (through electrophysiology) and the pharmacokinetics of acute and sub-chronic memantine treatment in blood plasma and the brain. Lifeng Gao1, Mingming Huang1, Hao Lei1 1Wuhan Institute of Physics & Mathematics, The Chinese Academy of Sciences, Wuhan, Hubei, China Type-I diabetes was induced in rats by a single injection of streptozotocin (STZ). Directional diffusion-weighted imaging on the optic nerves were performed at 4 weeks and 10 weeks on a 4.7 T scanner to monitor the early pathological changes induced by diabetes. Water diffusivities parallel and perpendicular to the axonal tracts were measured by the apparent diffusion coefficients ADC// and ADC(perpendicular), respectively. Compared to the control animals, the STZ-treated animals showed a trend of reduced ADC(perpendicular) in the optic nerves at 4 weeks, and significantly decreased ADC(perpendicular) at 10 weeks, but insignificant changes in ADC// at these time points. Xuxia Wang1, Fuchun Lin1, Tingzhu Lin1, Hao Lei1 1Wuhan Institute of Physics & Mathematics, The Chinese Academy of Sciences, Wuhan, Hubei, China In this study, diffusion tensor imaging and high resolution rapid-acquisition relaxation-enhancement (RARE) imaging were used to detect the morphological and structural changes in the brain of rats subjected to early bilateral enucleation at postnatal day 4. Profound atrophy was observed in the ON and OCH of the enucleated rats, likely a manifestation of transneuronal degeneration induced by deafferentation. The optic tract of the enucleated rats did not appear to be atrophic, but exhibited water diffusion abnormalities resembling those found in Wallerian degeneration. The primary visual cortex of the enucleated rats showed no changes in water diffusivity. Joao MN Duarte1, Anita Kulak2, Kim Q. Do2, Rolf Gruetter1,3 1Center for Biomedical Imaging (CIBM), Lausanne, Vaud, Switzerland; 2Centre for Psychiatric Neuroscience, Lausanne Univ. Hosp., Lausanne, Switzerland; 3Department of Radiology, Universities of Lausane and Geneva, Lausanne, Switzerland The present study reports alterations of the neurochemical profile in the cortex of a mouse model of redox deregulation induced by genetic reduction of glutathione synthesis. The observed metabolic alterations suggest impaired mitochondrial metabolism and eventually altered neurotransmission, both possibly triggering degeneration. 2359. An Automated Method to Optimize the Contrast of Small Structures Ryan Chamberlain1, Thomas M. Wengenack2, Joseph F. Poduslo2, Clifford R. Jack3, Michael Garwood1 1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States; 2Departments of Neurology, Neuroscience, and Biochemistry/Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, United States; 3Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN, United States Many MRI applications require visualizing structures on the order of a few pixels in size. In these applications the CNR ratio of the small structures is more important than the SNR of the image. The CNR can be affected dramatically by the image resolution relative to the size of the structure, but the exact relation of resolution and CNR depends on the specific structure and pulse sequence. This work describes an automated method to determine the acquired image resolution to optimize the CNR of small structures. It is demonstrated as applied to imaging amyloid plaques in transgenic mouse models of Alzheimer's disease. 2360. MR Elastography of the Brain in a Mouse Model of Alzheimer's Disease Matthew C. Murphy1, Geoffrey L. Curran2, Kevin J. Glaser1, Phillip J. Rossman1, John Huston, III1, Joseph F. Poduslo2, Clifford R. Jack1, Joel P. Felmlee1, Richard L. Ehman1 1Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN, United States; 2Department of Neuroscience, Mayo Clinic College of Medicine, Rochester, MN, United States Magnetic resonance elastography was performed in 5 wild-type (WT) mice and 5 Alzheimers disease (AD) mice. The AD model is a double mutation in amyloid precursor protein and presenilin-1 (APP-PS1), which leads to the extracellular deposition of amyloid protein and the formation of plaques with age. The AD mice were found to have a significantly lower mean stiffness compared to age-matched WT mice with a p-value of less than 0.01. The decrease in stiffness may result from mechanical changes in the extracellular matrix following amyloid deposition. Nicolau Beckmann1, Catherine Cannet1, Christelle Gerard1, Dorothee Abramowski2, Matthias Staufenbiel2 1Global Imaging Group, Novartis Institutes for BioMedical Research, Basel, BS, Switzerland; 2Nervous System Department, Novartis Institutes for BioMedical Research, Basel, BS, Switzerland MRI detected effects of cerebral amyloid angiopathy (CAA) in several lines of Alzheimers mice differing by amyloid-ß-40 (Aß40) contents. SPIO was administered i.v. 24h before MRI. Signal attenuations became apparent in multiple foci throughout the brain cortex and in thalamic regions of APP23 mice displaying high Aß40. At sites of MRI signal loss, iron was localized in microglia cells/macrophages in/or around damaged vessels. The small number of attenuated signal foci in the brains of APP24 and APP23xPS45 mice characterized by low Aß40 was consistent with histology showing significantly less vascular amyloid compared to APP23 animals. These results agree with Aß40 predominating in CAA-related vascular amyloid. 2362. MR Biomarkers of Neurodegeneration in a Transgenic Mouse Model of Alzheimer's Disease Ryan Chamberlain1, Malgorzata Marjanska1, Gregory Preboske2, Linda Kotilinek3, Thomas M. Wengenack4, Joseph F. Poduslo4, Karen H. Ashe3, Michael Garwood1, Clifford R. Jack2 1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States; 2Department of Radiology, Mayo Clinic, Rochester, MN, United States; 3Department of Neurology, University of Minnesota, Minneapolis, MN, United States; 4Departments of Neurology, Neuroscience, and Biochemistry, Mayo Clinic, Rochester, MN, United States The histological abnormalities that characterize Alzheimers disease are commonly divided into three major classes: amyloid plaques, neurofibrillary tangles and neurodegeneration. Much work has been done to image amyloid plaques using the APP/PS1 mouse model. However, the APP/PS1 model was developed to study amyloid plaques, and neurodegenerative changes are minimal in this model. The Tg4510 mouse model recapitulates neurodegeneration mediated through over expression of mutant human tau. In this work we compare the ability of various MR techniques (volume, T1ρ, T2ρ, ADC, FA) to detect neurodegeneration in the Tg4510 mouse model compared to wild-type mice. Dong-Cheol Woo1, Sung-Ho Lee2, Do-Wan Lee1, Sang-Young Kim1, Goo-Young Kim1, Hyang-Shuk Rhim1, Chi-Bong Choi3, Hwi-Yool Kim2, Chang-Wook Lee1, Bo-Young Choe1 1The Catholic University of Korea, Seoul, Korea, Republic of; 2Konkuk university of Korea; 3Kyung-Hee University of Korea, Seoul, Korea, Republic of This study was to investigate the regional neurochemical profile of APP-PS1 in the mouse brain of early-stage Alzheimer”Æs disease (AD) using 1H HR-MAS. Compared to the wild-type mice, the memory index (MI, behavioral test result) of the APP-PS1 mice at 18 weeks was not significantly different; however, the MI of the APP-PS1 mice at 35 weeks was significantly lower. The results of 1H HR-MAS showed that the [NAA+ Acet] level of the APP-PS1 mice decreased in the hippocampus and temporal cortex, mIns and sIns level was increased in the entire brain which are frontal, occipital, parietal cortex, hippocampus and thalamus. Thomas Neuberger1, Kristina Aldridge2, Cheryl A. Hill2, Jordan A. Austin2, Timothy M. Ryan3, Christopher Percival3, Neus Martinez-Abadias3, Yingli Wang4, Ethylin Wang Jabs4, Andrew G. Webb5,6, Joan T. Richtsmeier3 1The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, United States; 2University of Missouri-School of Medicine; 3Department of Anthropology, Pennsylvania State University, University Park, PA, United States; 4Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine; 5Department of Bioengineering, Pennsylvania State University, University Park, PA, United States; 6Department of Radiology, Leiden University Medical Centre, Leiden, Netherlands Apert syndrome (AS) is one of at least nine disorders considered members of the FGFR-1,-2, and -3-related craniosynostosis syndromes. Nearly 100% of individuals diagnosed with AS have one of two neighboring mutations on Fgfr2. The cranial phenotype associated with these two mutations includes coronal suture synostosis. Brain dysmorphology associated with AS is thought to be secondary to cranial vault or base alterations, but the variation in brain phenotypes within Apert syndrome is unexplained. Here we present novel MRM and µ-CT 3D data on brain phenotypes of mice each carrying one of the two Fgfr2 mutations associated with AS. Our data suggest that the brain is primarily affected, rather than secondarily responding to skull dysmorphogenesis. Detlef Stiller1, Thomas Kaulisch1, Selina Bucher1, Julia Tillmanns1, David Kind1, Heiko G. Niessen1, Krisztina Rona-Vörös2, Kerstin E. Braunstein2, Hans-Peter Müller2, Luc Dupuis3, Albert C. Ludolph2 1In-Vivo Imaging, Dept. of Drug Discovery Support, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany; 2Dept. of Neurology, University of Ulm, Ulm, BW, Germany; 3ISERM U692, Strasbourg, France A mouse with a point mutation in the gene encoding the motorprotein dynein is characterized by abnormal reflexes and by progressive motor and behavioral abnormalities without motor neuron degeneration. Even though previous studies showed age-dependent striatal astrocytosis and dysfunction, no in-vivo characterization of the brain has been performed yet. To investigate structural and functional alterations in the mouse brain, longitudinal MRI and [18F]-Fallypride PET were performed. In mutant mice the striatum size was significantly decreased, that of the ventricles significantly increased. PET imaging revealed a significantly reduced striatal uptake of Fallypride, supporting the theory of cell loss in the structure. 2366. Gliogenesis in Live Animals Using Targeted MRI: Detecting Neural Progenitor Cells in Vivo Philip K. Liu1, Christina H. Liu1 1Radiology, Mass General Hospital/Harvard Medical School, Charlestown, MA, United States Recruitment of specific cells is associated with tissue repair. Cell typing especially at the level of the DNA or RNA, has long depended on tissue biopsy of affected organs or postmortem investigation. The ability to evaluate therapies that might overcome such perturbations by using genes or cells (gene or stem cell therapies) in a host has been significantly limited. We have developed probes for specific cell type detection using mRNA targeting antisense DNA and contrast-enhanced MRI in live animals. Examples of detecting neural progenitor cells during brain repair after cerebral ischemia using targeted MRI in vivo will be presented. Philippine Camilla Geiszler1,2, Lynn Bedford3, R John Mayer3, Dorothee P. Auer1, Clare A. Daykin2 1Division of Academic Radiology, School of Clinical Sciences, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Division of Molecular and Cellular Sciences, School of Pharmacy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 3School of Biomedical Sciences, University of Nottingham, Nottingham, Nottinghanshire, United Kingdom This NMR spectroscopy-based metabolic profiling pilot study was conducted to examine the ability to characterise early effects of neurodegeneration in ubiquitin proteasome-depleted mice. In specific brain areas, these animals develop pyknotic nuclei preceding Lewy body-like neuronal inclusions and extensive neuronal loss. Cortices and hippocampi were extracted at the pyknotic nuclei stage. Liquid-state spectra, recorded at 400MHz, showed significant metabolic alterations (N-acetylaspartate, taurine, choline) in both areas indicative of substantial neuronal cell remodelling before neuronal death. The investigation demonstrated clearly the ability of NMR-based metabolic profiling techniques to aid in the characterisation of early neurodegeneration. 2368. Assessing Lysosomal Pathology Using Magnetic Resonance Imaging Yuan Mei1, Robia G. Pautler2 1Department of Psychology, Rice University, Houston, TX, United States; 2Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX, United States There are many neurodegenerative diseases that cause lysosomal pathology including Alzheimers and Sandhoff disease. In these disorders, cellular irregularities disrupt the lysosomal membrane and cause the organelle to lose its internal acidity. Using a convertible T1 contrast agent sensitive to acidity, we hypothesize that magnetic resonance imaging (MRI) can be used to detect lysosome membrane permeabilization and loss of acidity in mouse models with lysosomal pathology. If successful, this methodology can potentially be applied in vivo and used as a tool to improve current diagnostic methods for neurological disorders such as Alzheimers disease. Alejandra Sierra1, Kimmo Lehtimäki1,2, Teemu Laitinen1, Lassi Rieppo3,4, Asla Pitkänen1,5, Olli Gröhn1 1Department of Neurobiology, A.I. Virtanen for Molecular Sciences, University of Kuopio, Kuopio, Finland; 2Cerebricon Ldt., Kuopio, Finland; 3Department of Physics, University of Kuopio, Kuopio, Finland; 4Department of Anatomy, Institute of Biomedicine, University of Kuopio, Kuopio, Finland; 5Department of Neurology, Kuopio University Hospital, Kuopio, Finland Diffusion tensor imaging (DTI) in combination with tract-based spatial statistics (TBSS) analysis provides valuable anatomical information about changes in brain areas contributing to epileptogenic process. Lateral thalamic nuclei are one of the areas highlighted in TBSS showing increased FA 6 months after status epilepticus in rats. The present work is focused to characterize the interrelationship of histopathological changes and ex vivo DTI in combination with TBSS analysis using several histological stainings and polarized light microscopy. 2370. Brain Behavior Relationship in Wild-Type Mice and a Mouse Model of Huntingtons Disease Jurgen Germann1, Jeffrey B. Carroll2, Christine Laliberte1, R. M. Henkelman1, Michael R. Hayden2, Jason P. Lerch1 1The Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada We examined brain-behavior correlations in mice using MRI and 4 behavioural tests: Rotarod, Forced-Swim, Pre-pulse-Inhibition and Open Field test. Secondly, we investigated how these relationships are altered in a Huntingtons disease (HD) mouse model. Strong correlations were found in the wild-type mice identifying functional networks related to motor function, stress and anxiety, cortical gating and memory. The correlations are an expression of learning induced structural changes and provide insight into the study of brain networks controlling behavior; their absence in the HD mice could provide some insight into disease processes as they interfere with the changes normally induced by learning. Ines Blockx1, Marleen Verhoye1, Dirk Poot2, Johan Van Audekerke1, Huu Phuc Nguyen3, Stephan Von Hörsten4, Jan Sijbers2, Annemie Van der Linden1 1Bio Imaging lab - University of Antwerp, Antwerp, Belgium; 2Vision Lab - University of Antwerp, Antwerp, Belgium; 3Department of Medical Genetics - University of Tübingen, Tübingen, Germany; 4Experimental Therapy - Friedrich-Alexander University, Erlangen, Germany Diffusion Kurtosis Imaging (DKI) quantifies the well known non-gaussianity of the diffusion process in biological tissue and is therefore an indicator of microstructural complexity. HD is a progressive late-onset neurodegenerative disorder and is characterized by the formation of huntingtin aggregates and degeneration of the corticostriatal network. In the present study, we used the microstructural sensitivity of DKI, to detect neurodegeneration in symptomatic tgHD rats at the age of 16 months. Region of interest analyses revealed significant differences of DT and DK parameters in grey (caudate putamen) and even in white matter (external capsula) structures. Olivier Clerk-Lamalice1, Pierre Gravel2, Luc Tremblay1, Roger Lecomte1, Lionel Carmant3,4, Martin Lepage1 1Centre dimagerie moléculaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada; 2Département de radiologie, Hōpital Notre-Dame du Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada; 3Centre de recherche de lhōpital Sainte-Justine, Université de Montréal, Montreal, Quebec, Canada; 4Groupe de recherche sur le systčme nerveux central, Université de Montréal, Montreal, Quebec, Canada A new animal model has been developed to study the relation between cortical dysplasia, hyperthermic seizure (HS) and temporal lobe epilepsy (TLE). In this study, volumetric MRI, T2-weighted signal intensity and PET were used to better understand the neurodevelopmental changes that occur after HS in a predisposed brain and a possible link with the development of TLE. Our results suggest a causal relationship between a T2-weighted signal change resulting from metabolism/vascularisation imbalance after HS and a consequent developmental delay of the hippocampus. Valerio Zerbi1, Diane Jansen1, Andor Veltien2, Amanda Kiliaan1, Arend Heerschap2 1Anatomy, UMC St. Radboud, Nijmegen, Netherlands; 2Radiology, UMC St. Radboud, Nijmegen, Netherlands Impaired cerebral macro- and microvascular perfusion play an important role in the development of Alzheimers disease(AD). Here, a post-processing method is evaluated to distinguish and quantify cerebral blood volume(CBV) in macro- and microvasculature with contrast-enhanced MRI in a transgenic mouse model for AD. A comparison between steady-state CBV computations is presented, and histogram analysis is used to separate between vascular compartments. Results showed a decrease in hippocampal microvascular CBV as consequence of aging and genotyping that is not visible without separation of vascular compartments for macro- and microvasculature perfusion. Megan P. Phillips1, David K. Powell2, Zhiming Zhang3, Richard Grondin3, Peter A. Hardy3 1Center for Biomedical Engineering, University of Kentucky, Lexington, KY, United States; 2MRISC, University of Kentucky; 3Anatomy and Neurobiology, University of Kentucky Parkinsons Disease (PD) is a common neurodegenerative disease characterized by loss of motor control. PD results from the loss of dopamine-producing neurons in the substantia nigra (SN). Depletion of the dopamine neurons in the SN affects white matter tracts connecting the SN to the putamen. Using diffusion tensor imaging (DTI) , the goals of our research are first to identify the white matter tracts between the SN and putamen effected by the depletion of dopamine and second, identify the effects of age on white matter, specifically, fractional anisotropy (FA) and mean diffusivity (MD). Moon-Hyun Yoon1, Hyun-Jin Kim2, Jin-Yeung Jang2, Bo-Young Choe1 1Biomedical Engineering, Medical College, The Catholic Univ. of Korea, Seoul, Metro of Seoul, Korea, Republic of; 2Lee Gil Ya Cancer and Diabetes Institute, GACHON University of medicine and Science, Seoul, Korea, Republic of We found that inflammatory process was significantly associated with the highest peak height value of MTR histogram in the striatum and the SN. A possible explanation for this could be the early phase of the influence of specific neurotransmitters on the mean MTR values. The higher peak height of the MTR histogram in the striatum and SN was significantly associated with higher Glx/Cr ratios after MPTP intoxication suggesting neuronal dysfunction. The pathological studies in PD model clearly demonstrate the presence of disseminated activated microglial-like inflammatory cells in the central nervous system. John Totenhagen1, Ivan Borbon2, Eriko Yoshimaru1, Christine Howison3, Robert P. Erickson2, Theodore P. Trouard1 1Biomedical Engineering, University of Arizona, Tucson, AZ, United States; 2Pediatrics, University of Arizona, Tucson, AZ, United States; 3Arizona Research Laboratories, University of Arizona, Tucson, AZ, United States Results are presented from a longitudinal study of T2 and MRS measurements in a mouse model of Niemann-Pick Type C (NPC) disease to examine T2 measurements and MRS as possible indicators of disease progression and response to therapy in NPC disease. Adriaan Campo1, Ove Wiborg2, Helene Benveniste3, Annemie Van Der Linden1 1Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium; 2Center for psykiatrisk forskning, Århus Universitetshospital Risskov, Risskov, Århus, Denmark; 3Medical Department, Brookhaven National Laboratory, Upton, NY, United States MR spectroscopy was used to assess neurochemical changes in the hippocampus of the CMS rat model for depression. Besides the well known anhedonic phenotype, and control animals, a third group of animals was included: so-called stress resilient animals. These animals show different symptoms when subjected to prolonged stress. We suppose that these different sings of depression are due to different modulation of the HPA axis, as assessed by glutamate levels in the hippocampus: normal stressed animals show higher glutamate concentration, while the abnormal subgroup shows similar glutamate concentration as the control animals. Dana Suciu1, Alize E. H. Scheenstra2, Jouke Dijkstra2, Melly Sylvana Oitzl3, Louise van der Weerd, 1,4 1Radiology, LUMC, Leiden, Netherlands; 2Radiology - Image processing, LUMC, Leiden, Netherlands; 3Medical Pharmacology, LACDR, Leiden, Netherlands; 4Anatomy, LUMC, Leiden, Netherlands We report a longitudinal MRI investigation on mice chronically exposed to stress hormones (hypercorticism) to investigate hippocampal morphology. The mice were implanted with a continuous corticosterone-releasing pellet (n=10) or a placebo cholesterol pellet (n=10). T2W MRI scans of the mouse brain were taken over several weeks. Volumetric analysis by manual delineation using SPSS analysis and quantitative group-wise comparison using deformation fields and a 3D Moore-Rayleigh test with Bonferroni correction were employed. Our study demonstrated that chronic hypercorticism in mice indeed leads to volume loss in the hippocampus, which is at least partially reversible after recovery. 2379. Combined Vegf and Angiopoietin-1 Gene Transfer Using Aav Vectors After Spinal Cord Injury Juan Jose Herrera1, Ponnada A. Narayana1 1Diagnostic and Interventional Imaging, The University of Texas Health Science Center at Houston, Houston, TX, United States A consequence of spinal cord injury is the disruption of spinal vasculature, and it is this disruption that contributes to the initiation of cascade of biochemical events leading to secondary damage from the ischemic and inflammatory responses Using adeno-associated viral vectors engineered to express Ang-1 and or VEGF may stimulate angiogenesis and vessel maturation after spinal injury. Our study indicates that the syngeristic effect of both agents reduces spinal vascular permeability and lesion volume determined by MRI leading to functional recovery. Johann Le Floc'h1, Beau Pontré2, Winston Tan1, Srdjan M. Vlajkovic1, Peter R. Thorne1 1Physiology, The University of Auckland, Auckland, New Zealand; 2Centre for Advanced MRI, New Zealand Inner ear inflammation is thought to be a major contributor to the development of hearing loss and balance disorders. We report the results of the in vivo characterization of cochlear tissues inflammation induced by noise exposure or injection of bacterial lipopolysaccharide in two rodent species. The anaesthetized animals were scanned using a 4.7T MRI system. The calculated signal enhancement due to the observed uptake of a contrast agent was greater on inflamed than normal cochleae. MR findings correlated well with immunohistochemistry. We suggest that increase in gadodiamide uptake occurred as a consequence of increased vascular permeability. 2381. Cerebral Metabolite Assessment in Low and High Capacity Running Rats Using 1H-MRS Steven R. Roys1,2, Anjaneyulu Murugundla3, Su Xu1, Aurora Anderson3, Jiachen Zhuo1, Mark Limsam3, J Choi3, Lauren Koch4, Steve Britton4, Krish Chandrasekaran3, Paul Yarowsky5, James Russell3, Rao P. Gullapalli1,2 1Diagnostic Radiology & Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, United States; 2Core for Translational Research in Imaging @ Maryland (C-TRIM); 3Neurology, University of Maryland School of Medicine, Baltimore, MD, United States; 4Anesthesiology, University of Michigan, Ann Arbor, MI; 5Experimental Therapeutics and Pharmacology, University of Maryland School of Medicine, Baltimore, MD, United States Very little is understood regarding CNS changes that lead to various cognitive impairments among people with impaired glucose tolerance. Even less is understood regarding the differences between high performing diabetic patients versus the low performing diabetics. The purpose of this study was to examine the neurochemical profile differences between low capacity runner rats (LCR) and high capacity runner rats (HCR) using proton magnetic resonance spectroscopy at 7.0 Tesla. Findings suggest that LCR rats have elevated taurine, myo-inositol, glutamate and choline containing compounds compared to HCR rats consistent with similar findings in diabetic patients. 2382. Effect of Lactate on FMRI Responses Under Hypoglycemia Lihong Jiang1, Basavaraju G. Sanganahalli1, Peter Herman1, Raimund Herzog1, Robert Sherwin1, Fahmeed Hyder1, Douglas Rothman1, Kevin Behar1 1Yale University, New Haven, CT, United States We investigated BOLD responses to forepaw stimulation under insulin-induced acute hypoglycemic condition, as well as effect of lactate infusion under hypoglycemia condition. All high field fMRI experiments were conducted in α-chloralose anesthetized rats. The magnitude of the BOLD response in primary somatosensory (S1FL) region decreased from euglycemic to hypoglycemic conditions. Upon lactate infusion, under hypoglycemic condition, transiently increased S1 activities, but also recruited regions beyond S1FL. These results will benefit the understanding of brain function and metabolism, as well as the role of alternative fuels under hypoglycemic condition. MRS of Animal Brain Hall B Tuesday 13:30-15:30 Yun Xiang1, Jun Shen1 1National Institute of Mental Health, Bethesda, MD, United States In the carboxylic/amide region, brain 13C signals can only have one one-bond 13C-13C homonuclear coupling. As such only doublets (with a 13C-13C coupling of ~50 Hz) and singlets exist in this region. The large one-bond 13C-13C J coupling and the lack of interference from other isotopomers provide a unique condition for simultaneous detection of metabolism of different substrates. Examples of co-infusion of [13C6]-D-glucose and [1-13C] acetate as well as co-infusion of [13C6]-D-glucose and [1,3-13C2] hydroxybutyrate are shown to demonstrate in vivo simultaneous detection of different metabolic pathways in the brain using 13C MRS of the carboxylic/amide region. 2384. Alcohol as a Substitute for Acetate in 13 C MRS Study of Brain Metabolism Yun Xiang1, Jun Shen1 1National Institute of Mental Health, Bethesda, MD, United States Acetate is a glia-specific subtract and has been used to study brain metabolism. Potential risk in intravenously infusing sodium acetate to patients is unknown in many disorders. The effect of alcohol (ethanol) consumption is well understood. Alcohol is predominantly metabolized into acetate in the liver. In the present study, steady sate 13C spectra of rat brain acquired after administration of [1-13C] ethanol were found to be highly similar to spectra obtained using [1-13C] acetate, suggesting that oral administration of [1-13C] alcohol could replace intravenous infusion of sodium [1-13C] acetate in certain studies when the direct effect of alcohol is unimportant for the subject of the study. 2385. Neurochemical Profile of the Rat Lateral Septum Investigated with 1H-MRS Nathalie Just1,2, Maria-Isabel Cordero Campana3,4, Guillaume Poirier3, Hongxia Lei1,2, Carmen Sandi3, Rolf Gruetter1,5 1LIFMET, CIBM, EPFL, Lausanne, Switzerland; 2Department of Radiology, UNIL, Lausanne, Switzerland; 3Laboratory of Behavioural Genetics, EPFL, Brain and Mind Institute, Lausanne, Switzerland; 4Department of Child and Adolescent Psychiatry, HUG, Geneve, Switzerland; 5Department of Radiology, UNIL and HUG, Lausanne and Geneva, Switzerland The rat lateral septum has been shown to be involved in the expression of anxiety-behaviors such as those involved in conflict procedures. The neurochemical profile of the lateral septum has however never been characterized using proton magnetic resonance spectroscopy in the rat. In the present work, the neurochemical profile of the rat lateral septum was measured at 9.4T using 1H-MRS demonstrating significant changes compared to similar data measured in unspecific rat brain regions. It appears essential to characterize the metabolic profile of specific brain areas with accuracy using 1H MRS. Carine Chassain1,2, Guy Bielicki1, Yildiz Zengin2, Jean-Pierre Renou1, Franck Durif, 2,3 1NMR plateform, INRA, Saint Genes Champanelle, France; 2EA 3845, University of Auvergne, Clermont-Ferrand, France; 3service Neurology, CHU Clermont-Ferrand, Clermont-Ferrand, France Parkisnon's disease, 1H MRS, Glutamte, Glutamine, GABA, nucleus accumbens 2387. NMR Investigations of Excitatory and Inhibitory Neurotransmission in Mouse Brain Anant Bahadur Patel1, Vivek Tiwari1, A.L. Susmitha1, K.S. Varadarajan1 1NMR Microimaging and Spectroscopy, Centre for Cellular and Molecular Biology, Hyderabad, Andhra Pradesh, India Knowledge of neurotransmitter metabolism is very important for understanding the pathophysiology of neurological disorders. In the present study we have investigated neuronal TCA cycle and neurotransmitter cycle flux in different brain regions of C57BL6 mouse. Mice were infused with [1,6-13C2]glucose for different time ranging from 7 to 90 min or [2-13C]acetate for ~90 min. Brain metabolite levels and 13C labeling of amino acids were measured with 1H-[13C]-NMR spectroscopy at 14T NMR spectrometer. The metabolite levels were distinct in different regions of the brain. Glutamatergic rate was higher in cortex while GABAergic was more in cerebellum and olfactory bulb. Dong-Cheol Woo1, Chi-Bong Choi2, Sung-Ho Lee3, Eunjung Bang4, Sang-Soo Kim1, Hyang-Shuk Rhim1, Sang-Young Kim1, Bo-Young Choe1 1The Catholic University of Korea, Seoul, Korea, Republic of; 2Kyung-Hee University of Korea; 3Konkuk university of Korea; 4Korea Basic Science Institute This study was to characterize the regional neurochemical profiles of canine brain using NMRS, tissue extraction, and external simulated phantom concentration quantification. The occipital, frontal, and temporal lobes, thalami, cerebellar cortices, and spinal cords of adult beagles were obtained, and NMR samples were prepared using M/C extraction method. The metabolite concentrations in canine brain tissues were measured and compared with those found in human and rat brain. In addition, the cross peaks of brain metabolites were identified using 2D-COSY. This study demonstrated the absolute quantification of canine neuronal parts using MRS, with tissue extraction used to measure metabolite concentrations. Sang-Young Kim1, Hyun-Sung Lee2, Eunjung Bang2, Hyun-Ju Kim2, Sung-Ho Lee3, Do-Wan Lee1, Dong-Cheol Woo1, Chi-Bong Choi4, Bo-Young Choe1 1Department of Biomedical Engineering, The Catholic University of Korea, Seoul, Korea, Republic of; 2Korea Basic Science Institute, Korea, Republic of; 3Department of Veterinary Surgery, Konkuk University, Seoul, Korea, Republic of; 4Department of Radiology, Kyunghee University Medical Center, Seoul, Korea, Republic of The ketamine, a NMDA receptor antagonist, impair prefrontal cortex (PFC) function in the rat and produce symptoms similar to schizophrenia. In this study, we used in vivo and in vitro 1H-NMR spectroscopy to examine the brain metabolism of rat treated with subanesthetic dose of ketamine. In vivo data for Glu/Gln abnormalities in ketamine-treated rats may support the hypotheses of glutamate dysfunction for schizophrenia. In addition lower metabolic level of NAA in rats treated with ketamine may indicate reduced neuronal viability. Therefore our findings suggest that the neurochemical alterations induced by ketamine may provide the foundation for pathophysiological models of schizophrenia. 2390. In Vitro Proton MRS of Cerebral Metabolites in a Mouse Model of Alzheimer's Disease Duncan Forster1, Steve Williams2, Mike James3, Jill Richardson3 1University of Manchester, Manchester, United Kingdom; 2University Of Manchester; 3GlaxoSmithKline An in vitro proton MRS study was carried out on mice ranging from 3 to 18 months in order to investigate cerebral metabolic differences between TASTPM Alzheimer's mice and their wild type base strain. An effect of genotype was observed for myo-inositol, with concentration being higher in TASTPM mice, myo-inositol may therefore be an Alzheimer's marker. Lower levels of succinate were observed in TASTPM mice, being an effect of both age and genotype. This may indicate impaired neuronal energy production or mitochondrial dysfunction. The results also call into question the use of creatine as a reference metabolite. Hongxia Lei1,2, Lijing Xin1, Carole Berthet3, Lorenz Hirt3, Rolf Gruetter1,4 1LIFMET, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 2Radiology, University of Lausanne, Lausanne, Switzerland; 3Neurology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; 4Radiology, University of Geneva, Geneva, Switzerland 1H MRS of permanent focal middle cerebral occlusion (pMCAO) in mice could be feasible at high magnetic field. However, one of hydrolytic metabolites of NAA, acetate (1.9ppm), was heavily overlapped by accumulated GABA (1.89ppm) after pMCAO. In this study, we demonstrated that short echo time 1H MRS of measuring acetate was feasible at ultra short echo time using LCModel analysis when comparing to the measurements with minimal GABA contributions at a moderate echo time. 2392. In Vivo 1H MR Studies of Cortical Metabolic Response During Insulin-Induced Hypoglycemia Hongxia Lei1,2, Arthur W. Magill1,2, Vladimir Mlynarik1, Rolf Gruetter1,3 1LIFMET, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 2Radiology, University of Lausanne, Lausanne, Switzerland; 3Radiology, University of Geneva, Geneva, Switzerland Understanding hypoglycemia became very essential for treating diabetes in clinical. We explored 1H MR studies, including cerebral blood flow and neurochemical profile of cortical tissue under insulin-induced hypoglycemia in rats. Jaime M. Ross1,2, Johana Öberg3, Stefan Brené4, Giuseppe Coppotelli5, Mügen Terzioglu6, Karin Pernold1, Rouslan Sitnikov3, Jan Kehr7, Alexandra Trifunovic6, Nils-Göran Larsson6,8, Barry J. Hoffer2, Lars Olson1 1Neuroscience, Karolinska Institutet, Stockholm, Sweden; 2National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States; 3Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; 4Neurobiology, Health Sciences and Society, Karolinska Institutet, Stockholm, Sweden; 5Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden; 6Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden; 7Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; 8Max Planck Institute for Biology of Ageing, Cologne, Germany The prematurely ageing mtDNA mutator mouse was used to study mitochondrial dysfunction in the brain. 1H-MRS detected a 2-fold increase in cortical and striatal lactate levels as early as 6-9 weeks and continued throughout the lives of mtDNA mutator mice (average life span 45-48 weeks). Increased brain lactate levels were confirmed postmortem by high-performance liquid chromatography (HPLC). These methods revealed that abnormally high lactate levels in the CNS are an early phenotype of premature ageing in the mtDNA mutator mouse. Our data support the hypothesis of abnormal metabolism in ageing due to mitochondrial dysfunction. 2394. Mouse Brain Structure and Metabolic Stability Follows Focused Beam Microwave Irradiation Michael D. Boska1, Erin McIntyre1, Melissa Lynn Mellon1, Howard E. Gendelman2 1Radiology, University of Nebraska Medical Center, Omaha, NE, United States; 2Pharmacology and Experimental Neurosciences, University of Nebraska Medical Center, Omaha, NE, United States Mouse brain structural and metabolic stability were determined by T1 and T2 mapping and DTI at 0.7 and 0.9 s of 4 kW FBMI and by quantitative single voxel PRESS, respectively. Measures were taken in-vivo before and repetitively, at 1.17 hour intervals, after FBMI. Analysis continued for a total duration of 16 hours at room temperature. The longer FBMI duration was best for maintaining metabolite levels in the mouse brain; whereas T1, T2, and DTI metrics were best maintained by shorter duration FBMI. Ernest Brunton Cady1, Osuke Iwata2, Alan Bainbridge1, John Wyatt2, Nikki Jayne Robertson2 1Medical Physics & Bioengineering, UCLH NHS Foundation Trust, London, United Kingdom; 2Institute for Women's Health, University College London, London, United Kingdom Phosphoethanolamine concentration ([PE]) is high in neonatal brain. [PE] reduction increases mitochondrial respiration. We aimed to elucidate PE's metabolic role following hypoxia-ischaemia (HI). Thirty-three piglets were studied by 31P MRS (27 HI; 6 controls). For severe cerebral injury [PE]/[exchangeable phosphate pool] fell below controls but later recovered: however, [PE]/[nucleotide triphosphate (NTP; mainly ATP)] was almost constant suggesting strong PE to NTP coupling. In cells stressed after HI reduced [ATP] may inhibit ethanolamine phosphokinase resulting in [PE] reduction and stimulation of ATP generation by surviving mitochondria. High neonatal [PE] may be a factor evolved to counter mammalian cerebral birth trauma. 2396. Protective Actions of L-Carnitine in Ammonia-Precipitated Hepatic Encephalopathy Jane Missler1,2, Wenlei Jiang3, Dieter Leibfritz2, Claudia Zwingmann1 1Département de médicine, Centre de Recherche, Hōpital Saint-Luc, Université de Montréal, Montréal, Quebec, Canada; 2Department of Chemistry, University of Bremen, Bremen, Germany; 3Département de médicine , Centre de Recherche, Hōpital Saint-Luc, Université de Montréal, Montréal, Quebec, Canada Hepatic Encephalopathy is associated with hyperammonemia and energetic changes in brain. In animal models and patients with mild HE, L-carnitine has been shown to be protective. In order to investigate the effect of L-carnitine on brain energy-metabolism, multinuclear NMR was used to measure metabolic pathways in brain following administration of [U-13C]glucose in ammonia-treated rats with PCA. In ammonia-precipitated encephalopathy, L-carnitine considerably delayed the time to coma, concomitantly to enhanced ammonia detoxification via astrocytic glutamine synthesis and attenuation of lactate accumulation. These results indicate to cell-specific actions of L-carnitine which might explain its therapeutic effect in ammonia-precipitated HE in cirrhotic patients. Sang-Young Kim1,2, Chi-Bong Choi3, Yun-Jung Lee4, Hyeonjin Kim4, Do-Wan Lee1,2, Dong-Cheol Woo1,2, Jeong-Ho Chae5, Bo-Young Choe1,2 1Department of Biomedical Engineering, The Catholic University of Korea, Seoul, Korea, Republic of; 2Research Institute of Biomedical Engineering, Seoul, Korea, Republic of; 3Department of Radiology, Kyunghee University Medical Center, Seoul, Korea, Republic of; 4Gachon University of Medicine and Science, Incheon, Korea, Republic of; 5Department of Psychiatry, The Catholic University of Korea, Seoul, Korea, Republic of Until recently, no data are available about the behavioral and simultaneous non-invasive measurements of neurochemial responses following antidepressant treatment in mice FST model. In this study, in vivo 1H-MRS at 9.4 T was used to examine the effects of desipramine (DMI) pretreatment on behavioral and regional neurocheimal responses of C57BL/6 mice brain. We found significant behavioral changes as well as metabolic alterations of glutamate and myo-inositol by the DMI pretreatment. Our results suggest that glutamatergic activity and glial cell dysfunction contribute to pathophysiological mechanisms underlying depression and that modulation of synaptic neurotransmitter concentrations represent invaluable targets for antidepressant drug development. 2398. Implication of Myo-Inositol Metabolic Level in an Animal Model of Depression Sang-Young Kim1,2, Chi-Bong Choi3, Hyun-Sung Lee4, Sung-Ho Lee5, Dong-Cheol Woo1,2, Bo-Young Choe1,2 1Department of Biomedical Engineering, The Catholic University of Korea, Seoul, Korea, Republic of; 2Research Institute of Biomedical Engineering, Seoul, Korea, Republic of; 3Department of Radiology, Kyunghee University Medical Center, Seoul, Korea, Republic of; 4Korea Basic Science Institute, Korea, Republic of; 5Department of Veterinary Surgery, Konkuk University, Seoul, Korea, Republic of Animal models for depression are indispensable tools in the search to identify new antidepressant drugs. The forced swimming test (FST) is the most widely used tool for assessing antidepressant activity in rodents. Few studies have been performed proton spectroscopy to assess antidepressant effects on brain metabolism of rat exposed to the FST. The in vivo proton spectra quantified by LCModel revealed that myo-inositol metabolic level in left dorsolateral prefrontal cortex of rat was significantly altered in both FST and desipramine treated group. Our findings suggest a possible role of myo-inositol within the left DLPFC of rat model for depression. 2399. Effect of Morphine Exposure on Developing Rat Hippocampus Christopher M. Traudt1, Kathleen M. Ennis1, Raghu Rao1, Ivan Tkac2 1Dept. of Pediatrics, University of Minnesota, Minneapolis, MN, United States; 2University of Minnesota, Center for Magnetic Resonance Research, Minneapolis, MN, United States In vivo 1H NMR NMR spectroscopy at 9.4T was used to investigate effects of morphine on the neurochemical profile of the developing rat hippocampus. Significant differences between pup exposed to the morphine (2 mg/kg/, twice a day, P3 P7) and their littermate controls were observed for multiple brain metabolites on postnatal day 8. These changes had resolved by P29. Biochemical changes indicated effects of morphine on inhibitory neurotransmission (GABA, Tau), glial development and myelination (Gln, myo-Ins), osmoregulation (myo-Ins, Tau) and antioxidant processes (GSH).These results indicate that morphine exposure during hippocampal development may lead to hippocampal-dependant cognitive deficits in premature infants. Janna L. Harris1, Henry Yeh2, Nancy E. Berman3, William M. Brooks1 1Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS, United States; 2Department of Biostatistics, University of Kansas Medical Center, Kansas City, KS, United States; 3Department of Anatomy & Cell Biology, University of Kansas Medical Center, Kansas City, KS, United States N-acetylaspartate (NAA), a metabolite synthesized in neuronal mitochondria and detected by proton magnetic resonance spectroscopy (MRS), might serve as a non-invasive biomarker of mitochondrial integrity after traumatic brain injury (TBI). Previous studies in human survivors of TBI have linked NAA with cognitive recovery, although the specific mechanism has not been elucidated. We have examined a time course of changes in NAA and behavioral impairment after TBI in a well-characterized animal model. We then investigated whether these NAA changes are sensitive to manipulation of mitochondrial status by cyclosporine A (CsA), an experimental neuroprotective agent that inhibits mitochondrial permeability transition after TBI. Henk M. De Feyter1, Kevin Behar1, Lester R. Drewes2, Robin A. de Graaf1, Douglas L. Rothman1 1Diagnostic Radiology, Yale University, New Haven, CT, United States; 2Biochemistry & Molecular Biology, University of Minnesota, Duluth, MN, United States Repetitive iatrogenic hypoglycemic events lead to brain adaptations resulting in failing counterregulatory response and lack of warning symptoms (hypoglycemia unawareness) normally associated with low blood glucose levels. Increased blood-brain barrier lactate transport via upregulated monocarboxylic acid transporter 1 (MCT1) has been suggested as an adaptation induced by repetitive hypoglycemia. Increased lactate uptake and oxidation could (partially) replace glucose thereby contribute to hypoglycemia unawareness and failing counterregulatory response. We used 1H-[13C] MRS combined with [3-13C]-lactate infusion during hypoglycemia to investigate the role of increased lactate transport and/or metabolism in the brain of a rat model with ketogenic diet-induced upregulation of MCT1.
2402. Acute Flupirtine Administration Reduces Glutamate/glutamine Ratio in Rat Hippocampus Renuka Sriram1, Robert J. Mather2, Serguei Liachenko1 1BioImaging CoE, Pfizer Inc, Groton, CT, United States; 2Neuroscience, Pfizer Inc, Groton, CT, United States Neurotransmitter levels of glutamate and glutamine are tightly coupled with modulation of one resulting in a corresponding opposing change in the other. Since glutamate is implicated in a variety of neurological disorders, the observation of an endogenous pool of glutamate (Glu) and glutamine (Gln) and/or its ratio can serve as a strong mechanistic biomarker and measure of efficacy. Flupirtine, a potassium channel opener, has been shown to cause decrease in Glu and a relative increase in Gln in the rat hippocampus.
Wolfgang Weber-Fahr1, Gabriele Ende1, Alexander Sartorius1, Rainer Spanagel2, Claudia Falfan-Melgoza1, Dirk Cleppien1, Wolfgang H. Sommer2 1Neuroimaging, Central Institute of Mental Health, Mannheim, NA, Germany; 2Dept. Psychopharmacology, Central Institute of Mental Health, Mannheim, NA, Germany Out of a group of 17 animals eight were made dependent by 7 weeks ethanol vapor exposure with peak levels up to 4 g/l blood alcohol concentration. We assessed metabolic profiles in two brain regions with functional importance for dependence, i.e. medial prefrontal cortex and hippocampus, using in vivo single-voxel 1H magnetic resonance spectroscopy at TE=10 ms on a 9.4T scanner. Animals were measured up to 5 times before during and after ethanol exposure. Reduced myoinositol and N-acetylaspartate levels as well as increased choline-containing compounds were found during intoxication. Raised glutamate levels were found during early withdrawal. Nathalie Just1,2, Maxime Baud3, Jean-Marie Petit3, Pierre Magistretti3,4, Rolf Gruetter1,5 1LIFMET, CIBM, EPFL, Lausanne, Switzerland; 2Department of Radiology, UNIL, Lausanne, Switzerland; 3Laboratoire de neuroénergétique et dynamique cellulaire, EPFL, Lausanne, Switzerland; 4Brain and Mind Institute, Lausanne, Switzerland; 5Department of Radiology, UNIL and HUG, Lausanne and Geneva, Switzerland The present study examined the effects of sleep fragmentation (SF) in the hippocampus and the cortex of mice using proton MR spectroscopy at 14.1T. Disruptions in brain sensory processing and cognitive performance were seen during sleep fragmentation. Moreover, there is evidence that SF negatively affects memory and learning. Here, significant decreases in GABA and Lactate concentrations were detected in the hippocampus of mice following sleep fragmentation indicating decreased synaptic function in the hippocampus. Sung-Tak Hong1, Dįvid Zsolt Balla1, Gunamony Shajan1, Changho Choi2, Rolf Pohmann1 1High-Field Magnetic Resonance Center , Max-Planck Institute for Biological Cybernetics, Tuebingen, Baden-Wuerttemberg, Germany; 2Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States Regional differences of metabolites in the rat brain were investigated by using localized in vivo 1H MR spectroscopy at 16.4T. Three regions, thalamus, striatum and hippocampus, were investigated with an ultra-short TE STEAM sequence. The results demonstrated significant variations in all metabolites except aspartate and NAA. The remarkable variation of spectra was the substantially decreased level of the Tau methylene signal at 3.25 ppm in thalamus. The significant increase of the GABA methylene signal at 1.89 ppm was also observed in thalamus. Sung-Tak Hong1, Chi-Bong Choi2, Rolf Pohmann1 1High-Field Magnetic Resonance Center , Max-Planck Institute for Biological Cybernetics, Tuebingen, Baden-Wuerttemberg, Germany; 2Department of Radiology, Kyung Hee University Medical Center, Hoekidong, Seoul, Korea, Republic of The effect of different anesthetic agents was investigated in the rat brain by using in vivo 1H NMR spectroscopy. A volume-of-interest was placed in thalamus under two different anesthesia, isoflurane and ketamine/xylazine. The significant increase of glucose was observed in a deep ketamine/xylazine anesthesia while additional metabolic variations on ascorbate, aspartate, glutathione and lactate were detected. Chi-Bong Choi1, Sung-Tak Hong2, Sang-Young Kim3, Dong-Cheol Woo3, Bo-Young Choe3, Kyung-Nam Ryu1, Eun-Hee Kang1, Sung-Vin Yim1, Do-Wan Lee3, Rolf Pohmann2 1Kyung Hee University of Korea, Seoul, Korea, Republic of; 2Max Planck Institue for Biological Cybernetics; 3The Catholic University of Korea This study was to evaluate alterations in striatum metabolites of rats between anesthetized with isoflurane and ketamine/xylazine in vivo 1H-MRS at 16.4T, and to investigate the appropriateness of anesthetic agents. The concentrations of Ala, Asc, Asp, GABA, Gly and PCr were significantly different between isoflurane and ketamine/xylazine induced groups at the striatum. We demonstrated that metabolites in specific brain region can be differentially influenced according to anesthetic agents. This study showed that the choice of anesthetic is significant in the setting of 1H-MRS. Appropriate anesthetic choice should be pursued to exclude the effect of anesthetic agents on the target area. Head & Neck Imaging: Normal to Cancer Hall B Wednesday 13:30-15:30 Nicholas G. Dowell1, Edward H. Hughes2, Paul S. Tofts1 1Brighton and Sussex Medical School, Brighton, United Kingdom; 2Sussex Eye Hospital, Brighton, United Kingdom Accurate and precise T1 mapping of the eyeball is difficult due to eye movement and image distortions. An accurate measure of T1 could provide a non-invasive determination of eye oxygenation since T1 times are subtly increased by reduced partial pressure of oxygen (pO2) of the vitreous humour in the eye. Poor oxygenation leads to retinopathy and, in patients with low pO2 at the retina, a vitrectomy may be performed, where the vitreous humour is extracted and replaced by saline. However, there is no clear evidence that an increase in pO2 is actually achieved by this procedure and MRI would provide an important validation for ophthalmologists. We have developed a technique, using a TrueFISP acquisition sequence, which provides eye images with no movement artefacts, no image distortion and good SNR. This permits the measurement of T1 (and hence pO2) from the vitreous humour of the human eye. Furthermore, we show that asking a subject to fixate on a single point can control eye movement but the need to blink limits fixation to < 5 s. Consequently, we will provide an audio/visual cue that warns the subject when they must fixate. This approach to eye imaging could dramatically improve imaging of the eye and retina. 2409. Ultrashort Echo Time Imaging of the Middle Ear Ossicle: A Pilot Study Koji Yamashita1, Takashi Yoshiura1, Akio Hiwatashi1, Hironori Kamano1, Yukihisa Takayama1, Eiki Nagao1, Hiroshi Honda1 1Radiology, Kyushu university, Fukuoka, Japan Our purpose was to assess the feasibility of ultrashort echo-time (uTE) imaging for visualization of middle ear ossicles in normal subjects. Twelve volunteers with normal hearing levels were scanned at a 3.0T clinical unit using a dual-echo uTE sequence at TE1/TE2 = 0.14 ms/1.8 ms. In all subjects, the middle ear ossicles were clearly visualized as a high signal intensity spot on short TE images bilaterally, while they were not visible in long TE images in any of the subjects. To our knowledge, this is the first report of MR visualization of middle ear ossicles. 2410. Automatic Segmentation of Laryngeal Cartilages Using Support Vector Machines R. Reeve Ingle1, Berhane H. Azage1, Joėlle K. Barral1, Kie Tae Kwon1, Edward G. Damrose2, Nancy J. Fischbein, 2,3, Dwight G. Nishimura1 1Electrical Engineering, Stanford University, Stanford, CA, United States; 2Otolaryngology, Stanford University, Stanford, CA, United States; 3Radiology, Stanford University, Stanford, CA, United States MR is critical in the staging of laryngeal cancer. However, the presence and extent of cartilage invasion is difficult to assess. In this work, automatic intensity correction is integrated in a support vector machine algorithm, which is used to segment the cartilages from high-resolution MR images of the larynx. 2411. Dynamic MRI of the Temporomandibular Joint at 3 Tesla Using a Gradient Echo Sequence Yoon-Chul Kim1, John L. Go2, Sara Banerjee2, Meng Law2, Houchun Harry Hu1, Krishna S. Nayak1,2 1Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States; 2Keck School of Medicine, University of Southern California, Los Angeles, CA, United States Dynamic MRI may be useful for assessing temporomandibular joint (TMJ) dysfunction. This application requires sub-millimeter resolution and adequate contrast between the articular disc and surrounding tissue. A gradient echo sequence was optimized by first measuring the T2* values and then calculating the parameters of flip angle, TE, and TR that maximize the CNR efficiency. The dynamics of the TMJ disc was visualized with a 3.2 second temporal resolution, 0.5 × 0.5 mm2 in-plane spatial resolution using a 6-channel Carotid coil at 3 Tesla. 2412. Chemical Shift Imaging in the Head and Neck at 3T: Initial Results David K W Yeung1, Devin K. Fong1, Queenie Chan2, Ann D. King1 1Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong; 2MR, Philips Healthcare, Wanchai, Hong Kong Proton MRS is useful to probe tissue metabolism in vivo and its application yields considerable information about tissue biochemistry. In the head and neck, the detection of choline peak using single voxel spectroscopy has been found useful in confirming malignancy and treatment response. CSI is desirable for the study of large heterogeneous lesions, but shimming a large volume in the head and neck is challenging due to large susceptibility differences. We employed an anti-susceptibility device to improve the local field homogeneity. We examined 13 patients using this technique and we showed that CSI is feasible in the head and neck. Tobias Frauenrath1, Andreas Goemmel2, Christoph Butenweg2, Mario Otten3, Thoralf Niendorf1,4 1Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin, Germany; 2Chair of Structural Statics and Dynamics, RWTH, Aachen, Germany; 3Erich-Thienhaus-Institute, Hochschule für Musik, Detmold, Germany; 4Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany Even if some spatial insight can be obtained by stereoscopy imaging from classical optical methods or ex-vivo experiments, real 3D in-vivo measurements of vocal fold geometry are still elusive. Magnetic resonance imaging (MRI) is conceptually appealing for the pursuit of 3D imaging since it affords sub-millimeter spatial resolution and versatile tissue/muscle/cartilage image contrast. However, MRI comes with the penalty that it requires relatively long scan times. Hence, imaging of moving organs requires consideration of physiological motion. For the phonating vocal folds, periodic oscillation is superimposed by breathing movements (abduction and adduction). While for the first, synchronization cannot be obtained yet, the second can be handled by a customized explicit synchronization technique. The imaging protocol consisted of segmented 3D gradient-echo imaging and segmented 3D ultra-short TE. In vivo imaging on male and female subjects was conducted using a 3.0T in modal and head register. 3D MRI data were included into segmentation to derive boundary conditions for finite-element models of vocal fold oscillation. Thereby, the segmented air volume of the larynx is transformed in splines at different positions in the anterior-posterior axis of the vocal folds. 2414. MR Elastography of the Ocular Vitreous Body Daniel V. Litwiller1, Yogesh Mariappan1, Richard L. Ehman1 1Mayo Clinic, Rochester, MN, United States The gradual liquefaction of the ocular vitreous body with age can lead to retinal detachment and loss of sight. Although retinal detachment is a simple condition to diagnose, historically, means to evaluate the mechanical properties of the vitreous body have been invasive and technically challenging. The development of a reliable, noninvasive measurement technique would improve our understanding of the underlying physiology of this condition, and aid in evaluating patients and potential treatments. The purpose of this work was to investigate the utility of MR elastography as a noninvasive means to quantify the viscoelastic properties of the vitreous body. Cheng-Chieh Cheng1, Chun-Jung Juan2, Hsiao-Wen Chung, 2,3, Yee-Min Jen2, Su-Chin Chiu1, Hing-Chiu Chang, 1,4, Hui-Chu Chiu5,6, Cheng-Hsien Hsu2,7, Guo-Shu Huang2, Cheng-Yu Chen2 1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; 2Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan; 3Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan; 4Applied Science Laboratory, GE Healthcare Taiwan, Taipei, Taiwan; 5Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan; 6EMBA in Global Chinese Management, Department of Business Administration, Tamkang University, Taipei, Taiwan; 7Division of Software Design, Notebook Unit 5, Quanta Computer Inc., Taipei, Taiwan Parotid glands are highly radiosensitive, while the utilization of parotid sparing technique decreases the irradiation, and thus may reduce radiation therapy damage. In this study, we demonstrate a graded alteration in the perfusion characteristics of parotid glands, with the respect of parotid-sparing volume provided by the intensity modulated radiotherapy (IMRT) technique. 2416. High-Resolution Imaging of the Laryngeal Cartilages: Volunteer and Cancer Patient Studies Joėlle Karine Barral1, R. Reeve Ingle1, Edward J. Damrose2, Nancy J. Fischbein2,3, Dwight G. Nishimura1 1Electrical Engineering, Stanford University, Stanford, CA, United States; 2Otolaryngology, Stanford University, Stanford, CA, United States; 3Radiology, Stanford University, Stanford, CA, United States Current staging of laryngeal cancer and choice of optimal treatment are hindered by the difficulty of accurately assessing cartilage invasion. The use of a dedicated three-channel array instead of the conventional eight-channel neuro-vascular array allows a reduction in voxel size by a factor of 20. A low-order polynomial fitting approach is used to compensate for the coil sensitivity profile. In healthy volunteers, the increased resolution makes visible the delineation of non-ossified cartilage, otherwise indistinguishable from muscle. The dedicated array is also used in cancer patients, and improvement in image quality is demonstrated. Giovanni Giulietti1,2, Federico Torelli1,3, Marco Bozzali1, Girolamo Garreffa1,2, Nicola Moscufo4, Silvana Zannino1,5, Laura Serra1, Fabio Placidi5, Fabrizio Fasano1, Gisela Hagberg1, Bruno Maraviglia1,2, Ina Djonlagic6, Julian Saboisky6, Atul Malhotra6, Maria Grazia Marciani1,5, Charles Guttmann4 1IRCCS "Santa Lucia Foundation", Rome, Italy; 2"Enrico Fermi" Center, Rome, Italy; 3Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, United States; 4Center for Neurological Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, United States; 5Department of Neuroscience, University "Tor Vergata", Rome, Italy; 6Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, United States This VBM study aims at investigating GM and WM changes which might account for clinical disabilities in patients with OSAS. Sixteen patients with OSAS (grouped in moderate and severe clinical stage) and 14 healthy controls were investigated. Neuropsychological assessment and MRI scanning were obtained from each subject. Patients reported a selective impairment of verbal memory. Subjects with severe OSAS showed a bilateral GM atrophy of the hippocampus and some volumetric reductions in the contiguous WM. These findings suggest that both regional GM atrophy and WM disconnection might, at least parially, explain cognitive deficits detectable in patients with OSAS. Chun-Jung Juan1, Hing-Chiu Chang2,3, Cheng-Yu Chen1, Hung-Wen Kao1, Chun-Jen Hsueh1, Chih-Wei Wang1, Cheng-Chieh Cheng1,3, Su-Chin Chiu1,3, Hsiao-Wen Chung1,3, Guo-Shu Huang1 1Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan; 2Applied Science Laboratory, GE Healthcare Taiwan, Taipei, Taiwan; 3Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan In this study we aimed to verify the imaging quality of fast spin-echo PROPELLER diffusion weighted imaging (FSE-PROP-DWI) and echoplanar DWI (EP-DWI) in oral cavity and to investigate the apparent diffusion coefficient (ADC) of pathological proven oral tongue squamous cell carcinoma (OTSCC). Our results show that FSE-PROP-DWI is superior to EP-DWI with less imaging distortion and is satisfactory for measurement of ADC of OTSCC. Magalie Viallon1, Karen Masterson1, Minerva Becker1 1Radiologie, Hopital Universitaire de Genčve, Geneva, Switzerland Post Gadolinium MR head and neck examinations remain challenging due to the need for a large anatomic coverage in minimum acquisition time. For cranial nerves and skull base investigation, 3D acquisitions are very useful not only to better visualize and analyze the nerves but also to provide large head and neck coverage of often extended or multi focal pathology. Until recently, 3D acquisitions implemented to image the head and neck area were based on gradient echo imaging kernel (T1 3D Vibe FS, T1 MP-RAGE. Unfortunately, fast 3D T1w gradient echo imaging is limited by the presence of air-tissue interfaces and inherent susceptibility artefacts. Nevertheless, to study the whole course of nerves and localize focal or global contrast enhancement, a fat saturated spin-echo 3D T1 sequence seems more adequate. We investigate here the utility of 3D T1 FS Space (Sampling Perfection with Application optimized Contrasts using different flip angle Evolutions) for head and neck imaging at 3T and its clinical relevance in various pathologies of this region. Jacobus FA Jansen1, Heiko Schoder1, Nancy Lee1, Hilda Stambuk1, Ya Wang1, Matthew Fury1, Snehal Patel1, David Pfister1, Jatin Shah1, Jason Koutcher1, Amita Shukla-Dave1 1MSKCC, NY, United States The study aims to correlate pretreatment multimodality (MM) imaging data obtained with 1H-MRS, DCE-MRI and 18F-FDG PET in patients with head and neck squamous cell carcinoma (HNSCC) with neck nodal metastases for more precise assessment of the tumor metabolism and perfusion. Additionally, pretreatment MM imaging data was evaluated for its efficacy in prediction of short term response to treatment. In 29 HNSCC patients, Cho/W, Ktrans, ve, kep, 18F-FDG SUV measures were correlated. It was found that pretreatment MM imaging is valuable for the precise assessment of tumor biology, and maybe a predictive marker for short term response. DTI Brain & Spine - Clinical Applications Hall B Thursday 13:30-15:30 2421. MR Visualization of Ventral Thalamic Nuclei Kei Yamada1, Kentaro Akazawa, Sachiko Yuen, Mariko Goto, Shigenori Matsushima, Akiko Takahata, Tsunehiko Nishimura 1Radiology, Kyoto Prefectural University of Medicine, Kyoto, Japan Ventrointermediate nucleus of the thalamus is located adjacent to and medial to the pyramidal tract and it can be identified on anisotropy maps of diffusion tensor imaging as well as inversion recovery sequences. Yi Xiang Wang1, X L. Zhu2, M Deng1, Y W. Siu1, C S. Leung3, Q Chan4, T M. Chan2, W S. Poon2 1Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong; 2Division of Neurosurgery, Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital; 3Jockey Club Centre for Osteoporosis Care and Control, The Chinese University of Hong Kong, Prince of Wales Hospital; 4Philips Healthcare, Hong Kong SAR, China Using Diffusion tensor tractography, the relationship of Meyer”Æs loop to temporal lobe was investigated in 16 Southern Chinese subjects. Operator A is a neurosurgeon and BrainLAB software (Feldkirchen, Germany) was used. Operator B is a radiologist and Philips FiberTrak Software (Best, The Netherlands) was used. The results demonstrated a neurosurgeon and a radiologist using different DTT tools reached similar results on Meyer”Æs loop to temporal pole (MLØCTP) distance, suggesting BrainLAB and Philips FiberTrack software are able to provide comparable results. MLØCTP distance from southern Chinese population was similar to literature data of Caucasian and Japanese population. 2423. Diffusion Tensor Imaging Correlates of Cognitive Impairment and Fatigue in Multiple Sclerosis Gunja P. Parikh1, Maxim Bester1,2, Mariana Lazar1, James S. Babb1, Hina Jaggi1, Laura Miles1, Robert Grossman1, Matilde Inglese3,4 1Radiology, New York University, New York, NY, United States; 2Neuroradiology, Eppendorf-Hamburg University, Hamburg, Germany; 3Radiology , New York University, New York, NY, United States; 4Neurology, New York University, New York, NY, United States Diffusion tensor tractography provides the possibility to reconstruct fiber bundles and to focus on regions that might play a major role in the development of clinical deficits in patients with multiple sclerosis (MS). We used tractography to determine whether tissue damage in the corpus callosum (CC) and in the anterior-thalamic tracts (AT) is associated with cognitive dysfunction and fatigue in patients with benign MS (BMS) and clinically isolated syndrome (CIS). Differences from controls were observed in the CC and AT tracts of BMS and CIS patients. A significant association was found between DTI metrics in the CC and cognitive deficits. 2424. The Effects of HIV and Aging Using Diffusion Tensor Imaging Huiling Peng1, Joseph Mettenburg2, Avi Snyder1, David Clifford1, Tammie Benzinger2, Beau Ances3 1Neurology, Washington University in St. Louis, St. Louis, MO, United States; 2Radiology, Washington University in St. Louis, St. Louis, MO, United States; 3Neurology, Washington University in St. Louis, St. Louis, MO , United States HIV can lead to chronic inflammation. We investigated the relationship between aging and HIV status and white matter integrity using DTI in four groups of participants (HIV younger (20-25 years old) (n=8), HIV- older (50-65 years old) (n=12), HIV+ younger (20-25 years old) (n=9), and HIV+ older (50-65 years old) (n=9)). Regions-of-interest corresponding to the genus, middle, and splenium were selected. HIV- older subjects had significant decreases in mean diffusivity, axial diffusivity (AD), and radial diffusivity (RD) compared to other all groups. While HIV led to a reduction in DTI measures these decreases were not significant. Daniel Jon Peterson1, Sheryl L. Rimrodt2,3, Laurie E. Cutting4 1Developmental Cognitive Neurology, The Kennedy Krieger Institute, Baltimore, MD, United States; 2Division of Developmental Medicine, Children's Hospital at Vanderbilt, Nashville, TN, United States; 3Developmental Cognitive Neurology, Kennedy Krieger Institute, Baltimore, MD, United States; 4Kennedy Center for Research and Development, Vanderbilt University, Nashville, TN, United States DTI was used to investigate differences in white matter fiber orientation between three groups: children with reading disability (RD), children with neurofibromatosis type 1 and reading disability (NF1+RD), and typically developing controls. A voxel-wise statistical test that detects differences in fiber orientation revealed bilateral differences in the anterior limb of the internal capsule. In this region, the fiber orientation of controls and RD subjects were similar, while those of the NF1+RD subjects clearly differed, with minimal overlap. 2426. Voxel-Based Morphometric Analysis of Brain Volumetry and Diffusivity in Hepatitis C Manoj Kumar Sarma1, Rajakumar Nagarajan1, Charles H. Hinkin2, Steven A. Castellon2, Jason P. Smith, Homayoon Khanlou3, Laveeza Bhatti3, Jonathan Truong4, E Singer5, Jiah Jang6, Michelle Kim6, Gabe Waterman6, Rakesh Kumar Gupta7, Michael Albert Thomas1 1Radiological Sciences, UCLA, Los Angeles, CA, United States; 2Psychiatry and Biobehavioral Sciences, UCLA School of Medicine and VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States; 3AIDS Healthcare Foundation, Los Angeles, CA, United States; 4Kaiser Permanente, Lancaster, CA, United States; 5Neurology, UCLA School of Medicine, Los Angeles, CA, United States; 6VA West Los Angeles Healthcare System, Los Angeles, CA, United States; 7Radiological Sciences, SGPGIMS, Lucknow, UP, India We investigated mean diffusivity (MD) and fractional anisotropy (FA) value changes along with white matter and gray matter volume in patients with hepatitis C compared to healthy controls using voxel based morphometry (VBM). Extensive increased MD values were observed in bilateral frontal gray and white matter, bilateral external capsule, temporal white matter, and right occipital gray matter. FA values decreased in the corpus callosum, right frontal and occipital white matter. Widespread gray matter volume reduction was seen in the frontal, parietal and temporal regions. White matter volume decreases were observed in the right frontal, corpus callosum and mid brain. 2427. DTI Detects Progressive Neurodegeneration in the Brain and Cervical Spinal Cord in ALS Govind Nair1, John D. Carew2,3, Longchuan Li1, Sharon Usher4, Xiaoping P. Hu1, Michael Benatar4,5 1Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA, United States; 2Institute for Health Studies, Carolinas HealthCare System, Charlotte, NC, United States; 3School of Public Health, Emory University, Atlanta, GA, United States; 4Department of Neurology, Emory University, Atlanta, GA, United States; 5Department of Epidemiology, Emory University, Atlanta, GA, United States Diffusion tensor imaging of the brain and spinal cord in patients with Amyotrophic Lateral Sclerosis and age-matched healthy control subjects revealed a significant decrease in fractional anisotropy, and increase in mean diffusivity and radial diffusivity along the corticospinal tract. The DTI parameters from ALS patients showed significant correlation with their average finger and foot tapping speed, a measure of upper motor neuron dysfunction. These findings suggest that DTI might represent useful imaging biomarkers of ALS disease progression. 2428. Comparison of Limbic Regions FA Using Tractography-Defined ROIs in AD and MCI Darryl H. Hwang1, Sinchai Tsao1, Manbir Singh1 1Radiology and Biomedical Engineering, University of Southern California, Los Angeles, CA, United States The limbic regions appear to be affected by mild cognitive impairment (MCI) and Alzheimer Disease (AD). We use normalized tractography to objectively isolate the fornix and cingulum in a common template space for a voxel-based analysis of FA changes among normal control, MCI, and AD populations. The results show FA change propagation from normals to MCI to AD with more changes in the right hemisphere, which is consistent with previous reports. 2429. Axial and Radial Diffusivity Measures Detect Brain Tissue Injury in Heart Failure Patients Rajesh Kumar1, Mary A. Woo2, Paul M. Macey2,3, Gregg C. Fonarow4, Michele A. Hamilton4, Ronald M. Harper1,3 1Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States; 2School of Nursing, UCLA, Los Angeles, CA, United States; 3Brain Research Institute, UCLA, Los Angeles, CA, United States; 4Cardiology, UCLA, Los Angeles, CA, United States Heart failure (HF) patients show injury in multiple brain sites, which may represent axonal or myelin injury, or both; however, the nature of the injury is unclear. We assessed axial and radial diffusivity measures in HF, which show axonal and myelin changes, respectively. Axonal injury with reduced axonal density or caliber appeared in internal capsule and cerebellar regions, and reduced myelin in temporal and frontal areas. Other brain sites, including internal capsule and dorsomedial medulla showed myelin and axonal injury. The processes contributing to tissue injury in different brain regions are unknown, but may include ischemic/hypoxic or inflammatory processes.
Hsiao Piau Ng1,2, Marek Kubicki1,3, James Malcolm1, Yogesh Rathi1,3, Paula Pelavin1, Robert W. McCarley3, Martha E. Shenton1,3 1Psychiatry Neuroimaging Lab, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; 2Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore, -, Singapore; 3Clinical Neuroscience Division, VA Boston Healthcare System, Harvard Medical School, Brockton, MA, United States The connection between bilateral Heschls gyrus (HG) in normal controls (NC) and schizophrenics (SZ) is investigated using DTI here. Whole-brain tractography was first generated using filtered two-tensor tractography method, instead of conventional streamline tractography. The relevant connection was then extracted using the white matter of bilateral HGs as the ROIs. Measures for quantifying the connection are mean FA, mode, trace, parallel and perpendicular diffusivity. Statistically significant between-group differences in trace, parallel and perpendicular diffusivity were observed. Our findings are consistent with theories which suggest that SZ group has decreased WM pathology, particularly in regions associated with auditory and language processing. Hsiao Piau Ng1,2, Marek Kubicki1,3, Doug Terry1, Paula Pelavin1, Andrew Rausch1, Martha E. Shenton1,3 1Psychiatry Neuroimaging Lab, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; 2Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore, -, Singapore; 3Clinical Neuroscience Division, VA Boston Healthcare System, Harvard Medical School, Brockton, MA, United States In this study, the connection between the bilateral STGs in normal controls (NC) and schizophrenics (SZ) is investigated using DTI measures, namely FA, mode and trace. The connection was obtained from whole-brain streamline tractography using STGs white matter as ROIs. By dividing the connection into three sub-regions (Left, Corpus Callosum and Right) and comparing the computed DTI measures of NC and SZ, we found statistically significant differences in mean FA and mode in the Right region, with NC having greater values. This study paves the way for further localization of the differences in STGs connection between NC and SZ. Jungsu S. Oh1,2, Joon Hwan Jang2, Wi Hoon Jung3, Chi-Hoon Choi4, Jung-Seok Choi5, Do-Hyung Kang5, Jun Soo Kwon2 1Brain Korea 21 Division of Human Life Science, Seoul National University, Seoul, Korea, Republic of; 2Psychiatry, Seoul National University College of Medicine, Seoul, Korea, Republic of; 3Interdisciplinary Program in Brain Science, Seoul National University, Seoul, Korea, Republic of; 4Radiology, National Medical Center, Seoul, Korea, Republic of; 5Neuropsychiatry, Seoul National University Hospital, Seoul, Korea, Republic of Delineating frontostriatal network-related white matter tracts into dorsal/ventral pathways is of particular interest in obsessive-compulsive disorder (OCD) studies. Hence we aim to investigate fractional anisotropy (FA) of dorsal/ventral projections of callosal fibers in OCD on the basis of quantitative diffusion tractography analysis using Brodmann ROI approach and tract parameterization. We found significant FA decreases in callosal fibers of OCD in both DLPFC/OFC projections, benefitting from function/region-specific tractography analysis. Thus we validated well-known abnormalities in these networks of OCD. In particular, DLPFC-specific callosal fiber integrity was first revealed by the function/region-sensitivity of the present methods (not found by previous methods). Nasim Maleki1, Jaymin Upadhyay1, Jennifer Potter2, Roger Weiss, Lino Becerra1,3, David Borsook1 1PAIN Group, McLean Hospital, Harvard Medical School, Belmont, MA, United States; 2Division of Alcohol and Drug Abuse, Dept. of Psychiatry, McLean Hospital, Harvard Medical School, Belmont, MA, United States; 3Martinos Center, Massachusetts General Hospital, Charlestown, MA, United States White matter abnormalities in a cohort of prescription opioid dependent subjects (vs. demographically matched subjects) are assessed by combining the parcellated structural and DTI data. Our results show that there are significant changes in white matter in the patient group in the form of reduced fractional anisotropy. The approach used in this study to evaluate white matter integrity has the major advantage of taking individual anatomical differences into account for DTI analysis. Eni Halilaj1, Stephen Correia2, David H. Laidlaw1, Stephen Salloway3 1Computer Science, Brown University, Providence, RI, United States; 2Department of Psychiatry and Human Behavior, Warren Alpert School of Brown University; 3Neuroscience, Brown University In this study we use quantitative tractography to explore potential associations between cognitive functions and cerebral white matter pathways. We support inferences made about relationships between working memory, processing speed, motor function, executive function, visual naming and white matter health not only though observed correlations, but also through the lack thereof, in functions expected to rely more heavily on the functional integrity of cortical regions. Quantitative tractography metrics are powerful markers of structural integrity in white matter. Using such metrics, rather than diffusivity scalars, helps us identify underlying correlations between localized white matter atrophy and categorical cognitive decline. 2435. Improved Delineation of Brain Tumour Margins Using Whole-Brain Track-Density Mapping Stephen Rose1,2, Stuart Crozier, 2,3, Pierrick Bourgeat4, Nicholas Dowson4, Olivier Salvado4, Parnesh Raniga4, Kerstin Pannek5, Alan Coulthard6, Michael Fay7, Paul Thomas8, David Macfarlane8 1UQ Centre for Clinical Research, University of Queensland, Brisbane, Queensland, Australia; 2Centre for Medical Diagnostic Technologies in Queensland, University of Queensland, Brisbane, Queensland, Australia; 3Biomedical Engineering, University of Queensland, Brisbane, Queensland; 4The Australian e-Health Research Centre, CSIRO, Brisbane, Queensland, Australia; 5Centre for Magnetic Resonance, University of Queensland, Brisbane, Queensland, Australia; 6Medical Imaging, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia; 7Radiation Oncology, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia; 8Nuclear Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia We are investigating the use of HARDI, utilising whole-brain track-density maps to improve definition of brain tumour margins. Our hypothesis is that infiltrating tumour will reduce WM connectivity enabling improved depiction of tumour boundaries. To assist in the determination of tumour extent, the 3D visitation maps are anatomically fused to 18F-FDOPA PET images. We report that infiltrating tumour delineated on 18F-FDOPA maps that is present outside of the tumour-enhancement boundary defined on CET1 images results in a reduction in WM connectivity or streamline density on corresponding whole-brain track density maps. This has significant implications for surgical and radiation treatment planning. Chun-Yi Lo1, Wan-Yuo Guo2, Kun-Hsien Chou3, Ching-Po Lin1 1Institute of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan; 2Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan; 3Institute of Biomedical Engineering, National Yang Ming University, Taipei, Taiwan A virtual reality environment for integrating neuroanatomy was developed for clarify the relationship among tumor mass and peri-tumoral microstructures for facilitating neurosurgical trajectory design and optimizing therapeutic outcome. Brain tumor and edema were segmented manually and reconstructed into 3D display. Fiber tracking was carried out via the Fiber Assignment by Continuous Tracking algorithm with fractional anisotropy threshold of 0.2 and angular limitation of 60 degree. The 3D stereo image was projected on the non-depolarizing screen by two projectors with polarizing filter. Therefore, the viewings of the user”¦s right and left eyes would be slightly different and the stereo image would be produced from the user”¦s viewpoint with 3D glasses. Bradford Moffat1, Christopher Steward1, Patricia Desmond1, Simon Salinas1, Andrew Morokoff2, Chris Kokkinos3 1Radiology, University of Melbourne, Melbourne, VIC, Australia; 2Surgery, University of Melbourne, Melbourne, VIC, Australia; 3Radiology, Royal Melbourne Hospital, Melbourne, VIC, Australia The aim of this study was to investigate whether a probabilistic tractography algorithm based on CSD (SDPROB) was superior for visualisation of the motor pathway in patients with high grade brain tumors. Track volume intersection (TVI) with independent fMRI identified eloquent cortex from SDPROB tractography was compared to traditional stream tracking algorithms based on CSD (SDST) and DTI eigenvectors (DTST). SDPROB was found to be significantly (p<0.01) superior to both SDST and DTST algorithms for mapping the motor pathway to the eloquent motor cortex. Zhixi Li1, Robert J. Young2,3, Kyung Peck4, Nicole Brennan2, Andrei I. Holodny2,3 1Columbia University College of Physicians and Surgeons, New York, United States; 2Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, United States; 3Brain Tumor Center, Memorial Sloan-Kettering Cancer Center, New York, United States; 4Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, United States The development of diffusion tensor (DT) imaging and tractography affords the ability to account for the white matter fibers and has the potential to be an important tool in neurosurgical navigation. In addition to the usual fiber tracking challenges related to small fibers that may make sharp turns and/or encounter crossing fibers, tractography in patients with brain tumors may be compromised by the tumor and/or the associated edema. In patients with brain tumors near the arcuate fasciculus, we hypothesize that tractography based on a probabilistic model will perform better than a standard deterministic model. Alberto Bizzi1, Francesca Ferrč2, GianMarco Castelli1, Maria Luisa Mandelli1, Sylvie Piacentini2, Francesca Ciaraffa1, Domenico Aquino1, Carlo Marras3, Francesco Di Meco3, Giovanni Broggi3, Carlo Lazzaro Solero3 1Neuroradiology, Fondazione Istituto Neurologico Besta, Milan, Italy; 2Neurology, Fondazione Istituto Neurologico Besta, Milan, Italy; 3Neurosurgery, Fondazione Istituto Neurologico Besta, Milan, Italy Fourteen patients with grade II glioma were evaluated longitudinally with fMRI and DTI-MR Tractography of the language network and Aachener Aphasie Test before surgery, at 3 and 12 months. Functional cortex and streamlines of the dorsal and ventral language pathways were mapped. Deficits in phonemic and semantic fluencies were prevalent in patients with glioma infiltrating the insula, temporal pole and stem and were associated with ventral pathway interruption. Left hemisphere dominance was preserved in most patients. These imaging data suggest that ipsilateral rather than contralateral mechanisms of functional reorganization of the language network are more common in grade II gliomas. 2440. Role of Diffusion Tensor Imaging in Diagnosis of Medial Temporal Lobe Epilepsy Heba Ali1, Mona Mohamed2, Yosra Abdullah, Ahmed Gaber, Yasser Abbas 1AIN SHAMS UNIVERSITY HOSPITALS, CAIRO, Egypt; 2JOHNS HOPKINS UNIVERSITY SCHOOL OF MEDICINE, BALTIMORE, MD, United States Modern MR techniques are helpful in assessment of patients presenting with seizures and EEG changes suggestive of temporal lobe epilepsy, yet having normal conventional magnetic resonance imaging (MRI) epilepsy protocol. Here, we performed diffusion tensor imaging (DTI), with quantitative assessment of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) combined with tractography for pertinent white matter tracts. Results revealed that DTI is helpful for more accurate assessment of patients with MTLE.
Maarten Vaessen1,2, Jaap Jansen3, Paul Hofman, Marielle Vlooswijk, Henriette Majoie, Mark de Krom, Albert Aldenkamp1,2, Walter Backes 1School for Mental Health and Neuroscience , Maastricht University Medical Centre, Maastricht, Limburg, Netherlands; 2Kempenhaeghe Epilepsy Institute, Heeze, Netherlands; 3Memorial Sloan-Kettering Cancer Center, New York, NY, United States Patients with chronic epilepsy commonly develop cognitive co-morbidity. Previously, it was observed that their declined cognitive performance was associated with loss of functional connectivity derived from functional MRI of memory and language tasks. In this study we aimed to identify impaired structural connections, obtained with fibre tractography, between brain regions commonly associated with language and memory function. We found that fiber connections between the left and right frontal lobe were significantly reduced in these patients and were correlated with IQ. 2442. Longitudinal Diffusion Tensor Imaging of Fornix Degeneration Following Epilepsy Surgery Min Liu1, Donald Gross2, B.Matt Wheatley3, Christian Beaulieu1 1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada; 2Neurology, University of Alberta, Edmonton, Alberta, Canada; 3Neurosurgery, University of Alberta, Edmonton, Alberta, Canada Diffusion tensor imaging (DTI) may be a sensitive method of following the unique phases of Wallerian degeneration of injured white matter fibers in human brain. Longitudinal DTI tractography of the fimbria-fornix was performed at several time points on three patients with temporal lobe epilepsy before and after their anterior temporal resections (several times within the first week and 2-4 months post-surgery). The diffusion parameters of the ipsilateral fornices showed unique dynamic changes, notably a reduction of parallel diffusivity acutely, while perpendicular diffusion curiously showed a smaller reduction within the first week followed by the expected increase at chronic times. 2443. FACT, Probability Maps and Gibbs Tracking for Preoperative Fiber Tracking in Epilepsy Surgery Irina Mader1, Constantin Anastasopoulos1, Valerij G. Kiselev2, Andreas Schulze-Bonhage3, Marco Reisert2 1Clinic for Neuroradiology, University Hospital Freiburg, Freiburg, Germany; 2MR Physics, Department of Radiology, University Hospital Freiburg, Freiburg, Germany; 3Section for Pre-surgical Epilepsy Diagnostics, Clinic for Neurosurgery, University Hospital Freiburg, Freiburg, Germany Problem: The protection of functional fiber bundles is essential in epilepsy surgery. The aim was to compare FACT, probability maps and Gibbs tracking in their relevance for the neurosurgeon. Methods: Ten patients received pre-operative fiber tracking (5 corticospinal tract, 5 optic radiation). Results: Probability maps and GIBBS tracking were successful for all fiber structures on the healthy and the pathologic side, whereas FACT was only successful in 5 cases on the pathological side and 6 on the healthy side. Conclusion: Probability maps and Gibbs tracking are superior to FACT. A higher specificity of Gibbs cannot be shown at the moment.
2444. Probability Maps Compared to FACT Algorithm in Human Gliomas Irina Mader1, Thao Nguyen Thanh1, Susanne Schnell2, Thomas Reithmeier3, Valerij G. Kiselev2 1Clinic for Neuroradiology, University Hospital Freiburg, Freiburg, Germany; 2MR Physics, Department of Radiology, University Hospital Freiburg, Freiburg, Germany; 3Clinic for Stereotactic and Functional Neurosurgery, University Hospital Freiburg, Freiburg, Germany Problem: The importance of FACT algorithm for surgical planning has been substantiated in the past. No clinical experience is available for probability maps. This work aimed to compare FACT and probability maps in human gliomas. Methods: 10 patients with human gliomas (4 WHO°II, 6 WHO°III) received both fiber tracking methods of the motor fibers arising from fMRI derived seed points. Results: Probability maps were successful in all cases. FACT failed in three cases with moderate to severe motor impairment. Conclusion: Probability maps seem to be superior to FACT, especially in cases with strong fiber deviations and present oedema. N. Jon Shah1,2, Irene Neuner1,2, Joachim Bernhard Maria Kaffanke1, Yuliya Kupriyanova1, Karl-Joseph Langen1, Hans Herzog1 1Institute of Neurosciences and Medicine 4, Medical Imaging Physics, Forschungszentrum Jülich GmbH, 52425 Juelich, Germany; 2Faculty of Medicine, Department of Neurology, RWTH Aachen University, 52074 Aachen, Germany PET imaging is well established for the diagnosis of brain tumours. Its metabolic specificity delivers valuable information about the malignancy and the extent of tumour tissue. Tumour growth forces the brain to reorganize itself to compensate for the lost areas. It has been shown that DTI is a valuable tool to demonstrate the plasticity of the brain and it therefore offers information about the reorganization caused by tumour growth as well as surgical intervention. The acquisition of trimodal PET, MP-RAGE and DTI data on an MR-PET hybrid scanner, capable of simultaneous MR and PET, to investigate plasticity and reorganisation in human brain tumours is demonstrated. Stephen Edward Jones1, Andreas Alexopolous, Erik Beall, Joanna Fong, Jorge Gonzalez-Martinez, Mark Lowe, Blessy Mathew, Dileep Nair, Imad Najm, Michael Phillips, Kenneth Sakaie 1Neuroradiology, Cleveland Clinic, Cleveland, OH, United States We present a comparison of in-vivo connectivity scores: one derived from electrophysiology (EP) signals in human brains monitored with parenchymal electrodes (for epilepsy workup); and the other from imaging connectivity methods such as HARDI and resting state fMRI. Assuming EP represent a gold standard of connectivity, this provides a validation of various connectivity scores derived from MRI. Nadia CF Scantlebury1, William Gaetz2, Elysa Widjaja, James Rutka3, Eric Bouffet4, Conrad Rockel1, Don Mabbott1 1Program in Neuroscience and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Biomagnetic Imaging Laboratory, Children's Hospital of Philadelphia, Philadelphia, PA; 3Neurosurgery, The Hospital for Sick Children; 4Haemotology/Oncology, The Hospital for Sick Children We used combined magnetoencephalography (MEG) and Diffusion Tensor Imaging (DTI) tractography methods to delineate the cortico-spinal tracts (CSTs) of an 11-year old female who presented with an arteriovenous malformation (AVM). Concurrent MEG-DTI techniques revealed a case of cerebral plasticity, whereby motor function of the patient remained intact despite the contra-lateral displacement of her CST by the AVM. These data support the use of the functional activation as a seed for launching neural tracts during pre-surgical evaluation in children. Moreover, these findings demonstrate that using a concurrent MEG-DTI approach to delineate CSTs is invaluable when evaluating plasticity in the developing brain.
2448. Role of FMRI and DTI in Assessing the Efficacy of Visual Neurorehabilitation. Preliminary Data Matteo Bendini1, Ingrid Inches1, Marissa Barabas2, Massimo Prior3, Monica Ronzon1, Stefano Curtolo1, Davide Canonico4, Carlo Alberto Marzi2, Francesco Di Paola1 1Neuroradiology Department, Ca' Foncello Hospital Treviso, Italy, Treviso, Italy; 2Department of Neurological and Vision Sciences, University of Verona, Italy; 3Faculty of Psychology, University of Padua, Italy; 4Department of Physics, Ca' Foncello Hospital Treviso, Italy Aim: Establish if f-MRI and DTI are valid (objective) tools to evaluate postchiasmatic damage. Materials and methods: 7 patients with HVFDs underwent to a neuro-psycological evaluation. A f-MRI and DTI sequences were applied to study the visual activation and the optic radiation. Two patients underwent to a visual rehabilitation treatment. Results: In all patients did not show an activation in the visual cortex ipsilateral to the injury. The contralateral visual area showed a normal pathway of activation. In the two patients treated, higher activation in the contralateral visual areas was observed. Conclusions: F-MRI and DTI are valid tools to study HVFDs. Joshua Paul Nickerson1, Michael B. Salmela2, Chris John Koski3, Trevor Andrews2, Christopher G. Filippi4 1Radiology, Fletcher Allen Healthcare/The University of Vermont, Burlington, VT, United States; 2School of Medicine, University of Vermont, Burlington, VT, United States; 3Political Science, James Madison University, Harrisonburg, VA, United States; 4Neuroradiology, Fletcher Allen Healthcare/The University of Vermont, Burlington, VT, United States MRDTI normative data from the optic nerves in 70 normal children was compared to diffusion parameters in children with lesions both intrinsic and extrinsic to the visual pathway. Significant decrease in FA and increase in ADC was present in intrinsic lesions, while extrinsic lesions where only mass effect on the nerves was present did not affect diffusivity or anisotropy. This may improve presurgical planning for visual pathway lesions. Antoine Feydy1, Pavel Lindberg1, Francois Rannou2, Jean-Luc Drape1, Marc A. Maier3 1Radiology B, Hopital Cochin, Paris, France; 2Rehabilitation, Hopital Cochin, Paris, France; 3LNRS, Universite Paris Descartes, Paris, France We used DTI to test if the severity of spinal canal stenosis is related to the degree of spinal white matter integrity in patients with cervical spondylosis. Patients and controls were studied with DTI of cervical spinal cord. The patients had lower FA than controls and increased spinal canal stenosis. The mean degree of spinal canal stenosis correlated with mean FA, i.e., patients with least cervical canal space had lowest FA values of the whole cervical spinal cord. The results show that DTI can quantify spinal cord white matter degeneration related to spinal canal stenosis in patients with cervical spondylosis. Advanced Imaging of Spine & Spinal Cord Hall B Monday 14:00-16:00 2451. Diffusion Tensor Imaging of the Normal and Injured Pediatric Spinal Cord at 1.5 T Feroze B. Mohamed1, Louis N. Hunter2, Nadia Barakat1, Chia-Shang Liu1, Haris Sair3, Amer Samdani2, Randal Betz2, Scott H. Faro1, John Gaughan1, Mary J. Mulcahey2 1Temple University, Philadelphia, PA, United States; 2Shriners Hospital for Children; 3Massachusetts General Hospital To measure and establish normative DTI parameters of healthy spinal cord tissue in children with idiopathic scoliosis as a means for comparison with children with spinal cord injury (SCI). 5 subjects with idiopathic scoliosis and 5 subjects with SCI were imaged twice using DTI. The SCI subjects showed reduced FA values and increased D values compared with control subjects. Test-retest reproducibility showed excellent inter class correlation (ICC) in all the control group DTI index values (>0.9) while the SCI group showed moderate ICC (>0.7). There were statistically significant correlations between the DTI indices and several ISNCSCI clinical impairment scores. Rafael Luis O'Halloran1, Samantha J. Holdsworth1, Stefan Skare1, Roland Bammer1 1Department of Radiology, Stanford University, Stanford, CA, United States A simple method for reducing the phase field of view in twice-refocused DTI EPI is presented and compared with full of view imaging in DTI of the upper spine. The 180-degree refocusing slice select pulses are played out on the phase encoding axis instead of the slice-encoding axis. This allows the phase field of view to be reduced to the width of the perpendicular refocusing slab without introducing wrap. Results show that the reduced field of view method produces diffusion weighted images of the cervical and thoracic spine that are less distorted than those of standard full field of view EPI for the same scan time. 2453. Spinal Cord Diffusion Tensor Imaging (DTI) and 1H-MR Spectroscopy (MRS) at 1.5T and 3T. Virginie Callot1, Yann Le Fur1, Jean-Philippe Ranjeva1, Guillaume Duhamel1, Patrick J. Cozzone1 1Centre de Résonance Magnétique Biologique et Médicale (CRMBM), CNRS, UMR 6612, Faculté de Médecine, Marseille, France Diffusion Tensor Imaging (DTI) and single-voxel 1H-MR spectroscopy (MRS) of the spinal cord (SC) are challenged by several difficulties, including strong magnetic field inhomogeneities, respiratory and cardiac movements, and small size of the spinal cord. Whereas several studies have shown promising results, there is scant literature comparing 1.5T and 3T MRI and MRS. In this abstract, we investigate the efficiency of the available manufacturer MRS and DTI sequences, in terms of image/spectra quality and metrics, at both 1.5T and 3T, for different spinal cord locations (thoracic and cervical levels) and for different imaging plane orientations (sagittal and axial). 2454. Diffusion Tensor MR Imaging of the Healthy Human Cervical, Thoracic and Lumbar Spinal Cord Rachael Lee Bosma1, Christopher Alan Kidd1, Patrick W. Stroman1,2 1Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada; 2Departments of Diagnostic Radiology and Physics, Queen's University, Kingston, Ontario, Canada A greater understanding of diffusion indices within the healthy spinal cord is necessary for comparison with clinical populations. Here we measured fractional anisotropy and apparent diffusion coefficient values for cervical (C2-C7), thoracic (T3-T8) and lumbar (T10-L1) regions of the cord. FA vs. ADC values were plotted and three clusters were determined using a k-means partition to characterize each region of the spinal cord. DTI indices in the healthy cord were observed to be relatively consistent across regions, indicating that changes in these indices as a result of trauma at any level can be characterized relative to these observed indices. 2455. Diffusion Tensor MR Characteristics of Cervical Spondylosis Benjamin M. Ellingson1,2, Jean-Louis Benae2, Shekar N. Kurpad2, Brian D. Schmit3, Mehmet Kocak1, Marjorie C. Wang2 1Dept. of Radiology, Medical College of Wisconsin, Milwaukee, WI, United States; 2Dept. of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States; 3Dept. of Biomedical Engineering, Marquette University, Milwaukee, WI, United States The objective of the current study was to characterize the diffusion tensor MRI (DTI) properties of the cervical spinal cord in patients diagnosed with cervical spondylosis. Axial DTI was performed throughout the region of highest cord compression in 17 patients with cervical spondylosis using a clinical 1.5T MRI system. Results showed spatially localized regions of high FA and low MD at the site of compression. Longitudinal ADC was significantly lower than historic controls, whereas transverse ADC was significantly higher than historic controls in regions adjacent to the site of compression. Results from this study suggest that FA and MD can be used to localize regions of the spinal cord under the largest degree of compression. 2456. Pitfalls of Spinal DTI in Cervical Spondylotic Myelopathy Enedino Hernandez Torres1,2, Alex L. MacKay2,3, Erin MacMillan4, Teodoro Cordova Fraga1, Alonso Ramirez Manzanares5, Armin Curt6, David Li2, Burkhard Mädler7, M Dvorak8 1Division de Ciencias e Ingenierias, Universidad de Guanajuato, Leon, Guanajuato, Mexico; 2Radiology, University of British Columbia, Canada, Vancouver, Brithish Columbia, Canada; 3Physics & Astronomy, University of British Columbia, Canada, Vancouver, Brithish Columbia, Canada; 4Clinical Research, University of Bern; 5Facultad de Matematicas, Universidad de Guanajuato, Guanajuato, Mexico; 6Spinal Cord Injury Center, University of Zurich; 7Philips Healthcare, Vancouver, Brithish Columbia; 8International Collaboration on Repair Discoveries Diffusion measures have proved to be useful in cervical spondylotic myelopathy (CSM). This study compared two methods of analysis for spinal DTI in CSM subjects and normals. The first approach defined the spine area on the basis of a fractional anisotropy threshold of 0.3; the second employed a threshold based upon eigenvector orientation within 45 degrees of the direction of the spine. The two approaches yielded markedly different diffusion measures in controls, in stenotic regions and in non-stenotic regions. Further examination revealed that the eigenvector orientation approach included signal from CSF and hence gave artifactual results. 2457. Optimization of Reduced Field of View (RFoV) Quantitative Diffusion MRI in Thoracic Spine David Michael Thomasson1, Leor Zach2, Laura Elizabeth Danielian3, Peter Guion2, Yuxi Pang4, Dimitrios Alexopoulos1, Nicholas John Patronas1 1Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD, United States; 2Radiation Oncology Branch, National Cancer Institute, Bethesda, MD, United States; 3EMG Section, National Institute of Neurological Disorders and Stroke, Bethesda, MD, United States; 4BU - MR, Philips Healthcare, Cleveland, OH, United States Reduced Field of View rFoV diffusion weighted imaging techniques improve quantitative ADC and FA data for sagittal acquired thoracic spine imaging at 3Tesla relative to 1.5T. While lower field has less distortions limiting the necessity of such techniques, the reduced SNR at 1.5T makes them less desirable using clinically acceptable scan times. Here we optimize the rFoV technique in thoracic spine to obtain the best possible data in a clinical population. Junqian Xu1, Eric C. Klawiter1, Joshua S. Shimony2, Abraham Z. Snyder, 12, Robert T. Naismith1, Agus Priatna3, Tammie Benzinger2, Anne Cross1, Sheng-Kwei Song2 1Neurology, Washington University in St. Louis, St. Louis, MO, United States; 2Radiology, Washington University in St. Louis, St. Louis, MO, United States; 3Siemens Medical Solution, United States We describe a reproducible in vivo human cervical spinal cord diffusion tensor imaging (DTI) protocol at 3T. The data acquisition and analysis procedures are described with examples from healthy (n = 17) and pathological human spinal (n = 2) cords. The described comprehensive approach (1) accounts for the natural curvature of the human spinal cord by covering C1-6 with separate tiltable slices/groups, (2) minimizes distortion and signal drop-out by localized shimming, (3) improves the robustness by motion-correction and motion-based outlier rejection, (4) corrects negative eigenvalues by non-negative non-linear DTI calculation, and (5) employs objective geometry based region-of-interest selection for tract identification. 2459. Stimulus Site and Modality Dependence of Functional Activity Within the Human Spinal Cord Yazhuo Kong1, Michael Lee2, Catherine Warnaby1, Vishwani Wanigasekera1, Mark Jenkinson1, Irene Tracey1, Jonathan Brooks1 1FMRIB centre, Department of Clinical Neurology, University of Oxford, Oxford, Oxfordshire, United Kingdom; 2Division of Anaesthesia, University of Cambridge, Cambridge, United Kingdom Chronic pain is thought to arise due to maladaptive changes occurring at the level of the spinal cord. To investigate such changes in humans, a non-invasive neuroimaging technique is desirable. We have investigated the functional response in the spinal cord of 18 healthy subjects to noxious stimulation using punctate and thermal stimulation of the left and right arms. Group analysis, revealed distinct regions of activity within the spinal cord that were dependent on both the side of stimulation and the type of stimulus used. These results present the first non-invasive evidence for a lateralised and stimulus-specific spinal cord response. 2460. Quantitative Magnetization Transfer Imaging of Human Cervical Spinal Cord at 3T Richard D. Dortch1,2, E B. Welch2,3, John C. Gore1,2, Seth A. Smith1,2 1Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; 2Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 3MR Clinical Science, Philips Healthcare, Cleveland, OH, United States The goal of this study was to determine the feasibility of performing quantitative magnetization transfer (qMT) at high resolution in the spinal cord on clinical 3T systems. While MT imaging has been used to assess brain tissue microstructure, similar studies in the spinal cord have been limited due to high resolution demands and motion. Presumably, spinal cord qMT studies would benefit from the increased SNR at 3T; however, such studies are limited by SAR constraints. To address these issues, we developed a high resolution qMT imaging protocol of the cervical spinal cord at 3T and acquired data in healthy subjects. Patrick Anton Bruno Freund1,2, Catherine Dalton3, Claudia Angela Michela Wheeler-Kingshott3, Janice Glensman1, David Bradbury1, Alan James Thompson2, Nikolaus Weiskopf1 1Wellcome Trust Centre for Neuroimaging, UCL Institue of Neurology, London, United Kingdom; 2Brain Repair and Rehabilitation, UCL Institue of Neurology, London, United Kingdom; 3Neuroinflammation, UCL Institue of Neurology, London, United Kingdom We have developed and validated a method for fast, simultaneous and high-quality imaging of the brain and cervical spinal cord (< 14 mins., 1 mm isotropic resolution) with the potential to detect, besides volumetric changes at cortical level, also changes at cervical level. It is based on a 3D MDEFT scan using an 8-channel receive head coil. Measures of cross sectional cord area, obtained with the MDEFT-based method, are in good agreement with the established standard based on 3D MPRAGE scans with dedicated spine coils, as determined in a group of healthy controls and subjects with traumatic cervical spinal cord injury. John D. Carew1,2, Govind Nair3, Sharon Usher4, Xiaoping P. Hu3, Michael Benatar4 1Carolinas HealthCare System, Charlotte, NC, United States; 2Biostatistics and Bioinformatics, Emory University, Atlanta, GA; 3Biomedical Engineering, Emory University; 4Neurology, Emory University We studied MRS in the cervical spinal cord of amyotrophic lateral sclerosis (ALS) patients, healthy controls, and people with a mutation in the SOD1 gene. Single voxel PRESS/CHESS MRS was used to measure NAA, choline, creatine, and myo-inositol. We found metabolic changes in both ALS and people positive for the SOD1 mutation. Among ALS patients, metabolite ratios correlate with clinical measures of disease severity. The findings in the SOD1 positive sample suggests that metabolic changes occur prior to the onset of clinical symptoms. Johanna Oberg1, Matthias Erschbamer2, Rouslan Sitnikov1, Eric Westman3, Christian Spenger1, Lars Olson2 1CLINTEC, Karolinska Institutet, STOCKHOLM, Sweden; 2Neuroscience, Karolinska Institutet, Sweden; 3NEUROTEC, Karolinska Institutet, Sweden A variety of tests of sensorimotor function are used to characterize outcome after experimental spinal cord injury (SCI). These tests, however, do not provide information about chemical and metabolic processes in the injured CNS. Here, proton magnetic resonance spectroscopy (MRS) was used to monitor chemical changes in CNS (brain and spinal cord) in vivo following SCI. Significant differences were found between control rats and injured rats. Multivariate data analysis was applied. Our findings suggest that MRS is a helpful tool to monitor metabolic changes in vivo in the brain and the spinal cord itself after spinal cord injury.
Virginie Callot1, Guillaume Duhamel1, Mohamed Tachrount1, Yann Le Fur1, Patrick J. Cozzone1 1Centre de Résonance Magnétique Biologique et Médicale (CRMBM), CNRS, UMR 6612, Faculté de Médecine, Marseille, France Non invasive investigations of the mouse spinal cord pathologies are currently based on anatomic and diffusion MRI. In this work, we investigated whether high-field MR Spectroscopy would be able to provide complementing biochemical information useful to describe the lesion and the repair processes. This preliminary study demonstrates the feasibility of longitudinal follow-ups with localized 1H-MRS in injured mouse spinal cord. 2465. In Vivo MR High Resolution T1rho Mapping of the Spine at 3T Using a Reduced-FOV Approach Ajit Shankaranarayanan1, Emine U. Saritas2, Dwight G. Nishimura3, Weitian Chen1, Eric Han1 1Global Applied Science Lab, GE Healthcare, Menlo Park, CA, United States; 2Dept of Electrical Engineering, Stanford University, Palo Alto, CA, United States; 3Dept of Electrical Engineering, Stanford University, Palo Alto, CA, United States It has been suggested that MR T1ń relaxation time may potentially be valuable to assess proteoglycan (PG) loss in the early stages of disc degeneration, a known cause for back pain. Previous T1ń mapping techniques have shown this to be true. However, clinical applicability of these techniques in spine is somewhat limited by either long scan time, lower resolution or insufficient coverage. This work aims to overcome these limitations by applying reduced-FOV technique, previously shown for diffusion imaging to T1ń imaging. In vivo experiments have been performed on 3T to show the usefulness of such a targeted approach in terms of higher resolution and shorter scan times while providing good coverage in spine. 2466. Ultrashort TE Imaging After Percutaneous Vertebroplasty Akio Hiwatashi1, Takashi Yoshiura1, Koji Yamashita1, Hironori Kamano1, Hiroshi Honda1 1Clinical Radiology, Kyushu University, Fukuoka, Japan uTE is feasible to evaluate cement distribution after percutaneous vertebroplasty Wei-Che Lin1,2, Hsiu-Ling Chen1, Yu-Fan Cheng1, Chun-Chung Lui1 1Department of Diagnostic Radiology, Chang Gung Memorial Hospital - Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan, Taiwan; 2Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan, Taiwan Decrease bone marrow perfusion as reflected by lower peak enhancement ratio (PER) value in dynamic contrast-enhanced MRI (DCE-MRI) can independently predict the presence of intraosseous cleft in patients with osteoporotic vertebral compression fractures.DCE-MRI can help distinguish the more frail patients after VCF suitable for more tailored anti-osteoporotic therapy and can also identify delicate osteoporotic patients for advance treatment before an injury can occur. Wenshu Qian1, Henry Mak1, Queenie Chan2, Koon Ho Chan3, Mina Kim1 1Diagnostic Radiology, The University of Hong Kong, Hong Kong, China; 2Philips Healthcare, Hong Kong, China; 3Medicine, The University of Hong Kong, Hong Kong, China Neuromyelitis optica (NMO) is an inflammatory and demyelinating disease which consists of optic neuritis and myelitis. Since it usually involves acute and severe attacks, early diagnosis is of vital importance for proper treatment. However, current diagnostic imaging techniques are not sensitive to degenerative changes in early stage of NMO. In this study, we aimed to investigate the normal appearing cervical spinal cord damage in patients with NMO using diffusion tensor imaging (DTI). Our results show DTI-derived metrics can sensitively assess the microstructural abnormalities, suggesting DTI may have great potential as a useful diagnostic tool in detecting early stage of NMO. Breast MR Hall B Tuesday 13:30-15:30 Dennis WJ Klomp1, Alexander Raaijmakers2, Mies Korteweg1, Bart van de Bank1, Cecilia Possanzini3, Vincent Boer1, Fredy Visser3, Nico van de Berg2, Peter Luijten1 1Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands; 3Philips Health Care MRI of the human breast at higher B0 fields, like 7T, can improve SNR, but may be restricted by non uniform excitation and restricted RF power deposition (SAR). Here we propose the use of a RF coil setup with focused field in the female breast to gain from the maximum sensitivity that can be obtained at 7T, illustrated by high resolution MRI and MRS in healthy subjects and patients. Ileana Hancu1, Laura Sacolick2, Seung-Kyun Lee1, W Thomas Dixon1, Randy Giaquinto1, Graeme McKinnon3, Vijayanand Alagappan4 1GE Global Research Center, Niskayuna, NY, United States; 2GE Global Research Center, Munich, Germany; 3GE Healthcare, Waukesha, WI, United States; 4GE Healthcare, Aurora, OH, United States The main cause of the shading and improper fat suppression artifacts in breast imaging at 3T was identified as a bimodal distribution of the excitation field. A correction approach, based on the permanent placement of a passive loop tuned to 150MHz over the (always weaker) right side of a standard 8 channel breast receive array, was shown to mitigate the problem, result in more uniform B1transmit, better fat suppression and higher SNR, all with lower specific absorption rate. Ke Nie1, Jeon-Hor Chen1,2, Daniel Chang1, Chieh-Chih Hsu2, Orhan Nalcioglu1, Min-Ying Lydia Su1 1Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, Irvine, CA, United States; 2Department of Radiology, China Medical University, Taichung, Taiwan Breast parenchymal pattern is a well-known risk factor. The commonly used term ”®breast density”Æ only measures the amount of breast tissue, not the relative distribution between the fat and fibroglandular tissue. In this study, we developed quantitative parameters to characterize different parenchymal distribution patterns (intermingled vs. central types) based on the segmented dense tissue on 3D MRI. In a dataset of 230 cases, the area under the ROC curve could reach to 0.94 using combined parameters. These features can be further used to investigate the relationship between parenchymal pattern and the cancer risk. 2472. Evaluation of Neoadjuvant Chemotherapy Response of Breast Cancer at 3.0T Jeon-Hor Chen1,2, s Bahri1, P Carpenter3, H-J Yu1, R Mehta4, O Nalcioglu1, M-Y Lydia Su1 1Center for Functional Onco-Imaging, UC Irvine, Irvine, CA, United States; 2China Medical University Hospital, Taichung, Taiwan; 3Department of Pathology, UC Irvine, Irvine, CA, United States; 4Department of Medicine, UC Irvine, Irvine, CA, United States The results analyzed from 3.0 T were consistent with our previous findings using 1.5T with a lower spatial resolution, suggesting that the limitation of MRI in diagnosis of post-NAC cancer cannot be improved with a higher SNR or a higher spatial resolution. Our current protocol at 3.0 T still could not detect residual tumor presenting as scattered cells or small foci, which often occurs in non-mass-like lesions. These types of invasive cancer cells do not need angiogenesis to survive, and if so, they will not show contrast enhancements. 2473. Reduction of Breast Density Following Tamoxifen Treatment Evaluated by 3-D MRI Jeon-Hor Chen1,2, Yeun-Chung Chang3, Daniel Chang1, Yi-Ting Wang3, Ke Nie1, Ruey-Feng Chang3, orhang Nalcioglu1, Chiun-Sheng Huang3, M-Y Lydia Su1 1Center for Functional Onco-Imaging, UC Irvine, Irvine, CA, United States; 2China Medical University Hospital, Taiwan; 3National Taiwan University, Taiwan We have demonstrated that the breast density analyzed based on a 3D MR method can be used to investigate the changes associated with tamoxifen treatment. We found a significant reduction in fibroglandular tissue volume and percent breast density after treatment, and the density reduction was positively correlated with the baseline density and treatment duration. Jeon-Hor Chen1,2, Ke Nie1, S Bahri1, Rita S. Mehta3, Chieh-Chih Hsu2, Fei-Ting Hsu2, Han-Ni Shih2, Muqing Lin1, orhang Nalcioglu1, M-Y Lydia Su1 1Center for Functional Onco-Imaging, UC Irvine, Irvine, CA, United States; 2China Medical University Hospital, Taichung, Taiwan; 3Department of Medicine, UC Irvine, Irvine, CA, United States We have demonstrated the feasibility of investigating the reduction of density following chemotherapy using a quantitative analysis method based on MRI. Patients receiving chemotherapy showed reduction of breast density, and that the effects were more pronounced in younger women than older (post-menopausal) women. The results suggest that the reduction of breast density after chemotherapy was possibly mediated through impaired ovarian function. The reduction could be clearly noted after 1 to 2 cycles of AC regimen. Although the density continued to decrease after 4 cycles of AC and the following Taxane regimen, the subsequent effect was smaller. 2475. Pushing Old Boundaries in Breast MRI: Non-Fatsaturated Dynamic Imaging at Very Short TE Christian Geppert1, Rolf Janka2, Berthold Kiefer1, Michael Uder2, Evelyn Wenkel2 1MR Oncology, Siemens Heatlthcare, Erlangen, Germany; 2Radiologisches Institut, Universitätsklinikum Erlangen, Erlangen, Germany In non-fatsuppressed dynamic breast imaging, it is a well accepted recommendation to acquire data at or close to echo times that fulfil the in-phase condition for fat and water, such as 4.7ms at 1.5T, in order to avoid partial volume effects that lead to signal cancellation at fat/water interfaces. Thus it is usually suggested of using either in-phase TE or TE less than 1.2ms resulting in a phase difference of below 90°. In a comparable parameter setting this would result in a decrease of 50% of the total acquisition time. With current gradient systems and fast imaging sequences this has now become possible without compromising the matrix size or the bandwidth. In this work we have set up an interleaved protocol approach to achieve a direct comparison of a minimum TE acquisition with a clinical standard protocol. Endre Grųvik1, Kjell-Inge Gjesdal2, Kathinka Kurz Dęhli3, Atle Bjųrnerud4 1University of Oslo, Oslo, Norway; 2Sunnmųre MR-klinikk, Aalesund, Norway; 3Stavanger University Hospital, Stavanger, Norway; 4Rikshospitalet University Hospital, Oslo, Norway This work presents a method for improving diagnostic accuracy in DCE MR-mammography by normalization of kinetic parameters following AIF deconvolution. The permeability related kinetic parameter Ktrans and the Ktrans-ratio between cancer tissue and breast parenchyma were investigated and compared based on their ability to differentiate between malignant and benign lesions. The result showed that employing a normalization approach may improve the diagnostically performance of the pharmacokinetic model by diminishing the prospective errors in the extracted AIF. Hendrik Laue1, Anja Hennemuth1, Volker Diehl1,2, Markus Thorsten Harz1, Horst Karl Hahn1, Heinz-Otto Peitgen1 1Fraunhofer MEVIS, Bremen, Germany; 2Institute of Magnetic Resonance Imaging, Central Hospital St.-Juergen-Strasse, Bremen, Germany The consensus on diagnosis of breast cancer with DCE-MRI is the use of sequences with high spatial and low temporal resolution, because of the in inhomogeneous distribution of pharmacokinetic properties in the tumor and the requirement to detect small lesions. The diagnostic in breast MRI today is therefore based on simple curve shapes rather than pharmacokinetic modeling. In this work, some pharmacokinetic modeling of contrast arrival time (CAT) and variation of low temporal resolution are carried out to identify pitfalls in the application and to identify techniques beneficial for the diagnostic performance of breast MRI. 2478. Preliminary Results Using a Split Dynamic Time Series for DCE MR-Mammography Kjell-Inge Gjesdal1, Endre Grųvik2, Atle Bjųrnerud3, Kathinka Kurz Dęhli4 1Sunnmųre MR-klinikk, Aalesund, Norway; 2University of Oslo, Oslo, Norway; 3Rikshospitalet University Hospital, Oslo, Norway; 4Stavanger University Hospital, Stavanger, Norway This work presents the preliminary results of an ongoing MR-mammography study. In this study two dynamic sequences are run in an interleaved fashion during contrast enhancement. By using this approach both high temporal and high spatial resolution images can be produced and analyzed for the evaluation of breast cancer using one single dose of a Gd-based contrast agent. A comprehensive list of biomarkers is presented along with their statistical values. Michael A. Jacobs1, Riham H. El Khouli2, Katarzyna J. Macura1, Sarah Mezban1, Ihab Kamel1, David A. Bluemke2 1The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2Department of Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD, United States By using a combined DWI/ADC and DCE approach to investigate histological characteristics of breast cancer a better understanding of breast cancer aggressiveness can be realized. Functional imaging such as DWI and DCE-MR is feasible and thus, combined DWI/ADC mapping, and DCE-MR provides radiological biomarkers of molecular environment and could provide targets for image-guided biopsy of highly aggressive tumor regions. Daria Badikhi1, Myra Shapiro-Feinberg2, Erez Eyal3, Edna Furman-Haran4, Dov Grobgeld1, Hadassa Degani1 1Biological Regulation, Weizmann Institute of Science, Rehovot, Israel; 2Radiology, Meir Medical Center, Kfar Sabah, Israel; 3Biological Regulation, Weizmann Institute of Science, Israel; 4Biological Services, Weizmann Institute of Science, Rehovot Principal component analysis (PCA) of clinical breast DCE MRI datasets, recorded at two different temporal resolutions (80 s and 120 s), was tested and evaluated for its diagnostic ability. We found that PCA can differentiate with high accuracy between benign and malignant lesions at both temporal resolutions, however, discriminative ability between invasive ductal and lobular carcinoma can be reached only at the higher temporal resolution. Overall, PCA was found to be a useful, standardized, fast, and objective tool for computer aided diagnosis of breast lesions Line R. Jensen1, Benjamin Garzon1, Mariann G. Heldahl1, Tone F. Bathen1, Pål E. Goa1, Steinar Lundgren1,2, Ingrid S. Gribbestad1 1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway; 2Department of Oncology, St. Olavs University Hospital, Trondheim, Norway The purpose of this study was to use MRI for early evaluation of treatment effects in breast cancer patients undergoing neoadjuvant chemotherapy, and to identify MRI parameters at 3T that correlate to treatment response. In addition, the reproducibility of diffusion weighted MRI was assessed. The ADC values from two baseline examinations showed good reproducibility, with ICC of 0.84. The best predictors of pathologic treatment response were the change in the longest diameter measured on MRI, followed by mean and skewness of ADC, and Ktrans entropy. Marco Borri1, Maria Schmidt1, Erica Scurr1, Toni Wallace1, Steven Allen1, Nandita deSouza1, Martin O. Leach1 1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, United Kingdom Spatial resolution of 3D fat-suppressed DCE pulse sequences depends on many parameters, and parity of protocols across breast screening centres is highly desirable. The objective of this work was to propose methods for quality assurance in breast screening programmes. We compared the image quality achieved with two different k-space sampling patterns, Radial and Linear, on a breast screening sequence. Resolution was evaluated with Test Objects and on Clinical Data, and, considering all three directions, was superior for Linear. The Image Analysis methodologies used were found to be robust and reproducible, and are therefore candidates to become quality assurance tools. Endre Grųvik1, Kjell-Inge Gjesdal2, Kathinka Kurz Dęhli3, Atle Bjųrnerud4 1University of Oslo, Oslo, Norway; 2Sunnmųre MR-klinikk, Aalesund, Norway; 3Stavanger University Hospital, Stavanger, Norway; 4Rikshospitalet University Hospital, Oslo, Norway This study investigates the influence of spatial heterogeneity on the diagnostic accuracy of DCE-MRI in breast tumor characterization. This is done by comparing the lesions VOI 50th-percentile versus VOI 95th-percentile values for a defined set of pharmacokinetic parameters, based on their ability for differentiating between malignant and benign lesions. Our results suggest that a significant improvement in diagnostic accuracy can be obtained by identifying the 5% region indicating the highest malignancy in the defined tumor VOI. 2484. Preliminary Results of a Physical Phantom for Quantitative Assessment of Breast MRI Melanie Freed1,2, Jacco A. de Zwart3, Jennifer T. Loud4, Riham H. El Khouli5, Mark H. Greene4, Brandon D. Gallas1, Kyle J. Myers1, Jeff H. Duyn3, David A. Bluemke5, Aldo Badano1 1CDRH/OSEL/DIAM, FDA, Silver Spring, MD, United States; 2Department of Bioengineering, University of Maryland, College Park, MD, United States; 3NINDS/LFMI/Advanced MRI Section, National Institutes of Health, Bethesda, MD, United States; 4NCI/Clinical Genetics Branch, National Institutes of Health, Rockville, MD, United States; 5Department of Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD, United States We are developing a physical, tissue-mimicking phantom to be used for task-based, quantitative assessment of breast MRI protocols. Here we present initial results of the phantom characterization and comparison to human data. Measured T1 and T2 relaxation values of the adipose- and glandular-mimicking phantom components agree with human values from the literature. The structure of human and phantom images is compared using the covariance kernel and found to match within patient variation. 2485. DSC MR-Mammography: Tumor Characterization Using Quantitative R2* Analysis Endre Grųvik1, Kathinka Kurz Dęhli2, Atle Bjųrnerud3, Kjell-Inge Gjesdal4 1University of Oslo, Oslo, Norway; 2Stavanger University Hospital, Stavanger, Norway; 3Rikshospitalet University Hospital, Oslo, Norway; 4Sunnmųre MR-klinikk, Aalesund, Norway This work presents the transverse relaxation rate, R2*, as a quantitative biomarker for distinguishing between malignant and benign breast lesions. R2* was estimated on a pixel-by-pixel basis by assuming a mono-exponential dependence of a double-echo intensity scheme, yielding from a high temporal resolution sequence. The study suggested that the peak change in the transverse relaxation rate is a sensitive biomarker for tumor malignancy in DSC MR-mammography. Ke Nie1, Jeon-Hor Chen1,2, Orhan Nalcioglu1, Min-Ying Lydia Su1 1Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, Irvine, CA, United States; 2Department of Radiology, China Medical University, Taichung, Taiwan Mathematical modeling provides a unique means to simulate different cancer growth patterns. However, the current published models included only functional information, few of them considered the effect of environmental structure. In this study, we simulated the breast tumor growth in the duct by coupling tumor growth and duct wall deformation. By varying the key parameters, we could identify key mechanisms for DCIS to progress to invasive cancer. The simulation result is further correlated with the lesion phenotype shown on MRI. Understanding these biological growth patterns of DCIS may be further used to refine diagnostic criteria. Bo Elizabeth Peng1, Sean Foxley2, Jeremy Palgen1, Robin Holmes2, Elizabeth Hipp2, Gillian Newstead2, Gregory S. Karczmar2, Devkumar Mustafi1,2 1Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, United States; 2Radiology, The University of Chicago, Chicago, IL, United States We tested several MRI methods for the identification and characterization of small calcium crystals for probing microcalcifications in breast cancer. High-resolution MR images were acquired of small Ca-crystals imbedded in air bubble-free agarose phantoms in clinical and research magnets. Two types of Ca-crystals that are commonly associated with benign and malignant breast lesions, are clearly detectable and distinguishable by MRI, but not distinguishable on x-ray mammograms. The present results lend support to the feasibility of clinical visualization and analysis of microcalcifications by MRI. Detection of microcalcifications by MRI would increase sensitivity and specificity for breast cancer detection. Richard Baheza1, Brian Welch2, John Gore3, Thomas Yankeelov3 1Biomedical Engineering, Vanderbilt, Nashville, TN, United States; 2Philips Healthcare; 3Institute of Imag Science and Dep of Radiology Sciences, Vanderbilt, Nashville, TN, United States The possibility of detecting calcium deposits in breast has been investigated by simulation and experimentally. Susceptibility weighted imaging is used to simulate and measure signature due to magnetic susceptibility difference between calcium and water in tissue. Simulated and experimental data with different levels of signal to noise ratio (SNR) and resolution are analyzed by two methods. Crosscorrelation between simulated phase and data, and the relative magnetic susceptibility difference map, computed directly from data. Both methods are compared to locate 1mm object induced signature. Results suggest SNRā„20 and voxel size ā¤ 0.25 mm (isotropic) are needed for both methods to work. 2489. Detection of Breast Micro-Calcifications with MRI at 3T: Riham Hossam El Din El Khouli1, David Thomasson1, Katarzyna Macura2, Sarah Mezban2, wei Liu3, Michael Jacobs2, Richard Edden4, Peter Barker2, David Bluemke1 1Radiology and Imaging Sciences, NIH/Clinical Center, Bethesda, MD, United States; 2Radiology and Radiological Sciences, Johns Hopkins University School of Medicine; 3NIH/NCI; 4Cardiff University Micro-calcifications (< 1 mm) are a fundamental marker of breast cancer by x-ray mammography, especially for the early diagnosis of ductal carcinoma in situ (DCIS). However with MRI, micro-calcifications are rarely detected using standard pulse sequences. The purpose of this study was to optimize MRI approaches for detecting micro-calcifications in the breast in comparison to mammography and conventional MRI. We achieved high spatial resolution and good visualization of micro-calcifications using a proton density weighted ultra-short TE MRI sequence with radial reconstruction. Ultra-short TE MRI has potential for detection of mammographically visualized micro-calcifications. Shannon Agner1, Mark Rosen2, Sarah Englander2, Diana Sobers1, Kathleen Thomas2, John Tomaszewski3, Michael Feldman3, Shridar Ganesan1, Mitchell Schnall2, Anant Madabhushi1 1Biomedical Engineering, Rutgers University, Piscataway, NJ, United States; 2Radiology, University of Pennsylvania, Philadelphia, PA, United States; 3Pathology, University of Pennsylvania, Philadelphia, PA, United States Previous studies based on visual inspection of breast tumors suggest that molecular subtypes of breast cancer are associated with distinct imaging phenotypes on DCE-MRI. In this study, we develop a computer-aided diagnosis tool that utilizes textural kinetics, an attribute that captures time related changes in internal lesion texture, to distinguish between 20 triple negative (estrogen receptor (ER) negative/ progesterone receptor (PR) negative/ human epidermal growth factor (HER2) receptor negative) and 21 ER positive tumors. Our CAD system was found to outperform classifiers that were driven by morphology, signal intensity kinetics, peak contrast texture, and pharmacokinetic parameters. Marcel Gutberlet1, Anne Roth1, Dietbert Hahn1, Herbert Köstler1 1Institut fuer Roentgendiagnostik, University of Wuerzburg, Wuerzburg, Bavaria, Germany A novel method is presented allowing improving 3D-MRI. Virtual coil deconvolution imaging for effective density weighted imaging (VIDED) combines the virtual coil concept with density weighted imaging. DW imaging allows improving the spatial response function at an optimal signal-to-noise ratio but at the expense of incoherent aliasing. In VIDED imaging this aliasing is suppressed by virtual coil deconvolution imaging which is a method allowing parallel imaging even for single receiver coils. VIDED imaging was applied in slice direction of 3D-MRI improving the slice profile, increasing the SNR up to 17% and the FOV in slice direction approximately by 25%. Che A. Azlan1,2, Trevor S. Ahearn1, Pierluigi Di Giovanni1, Scott I.K. Semple3, Fiona J. Gilbert1, Thomas W. Redpath1 1Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, Scotland, United Kingdom; 2Department of Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia; 3Department of Medical Physics, University of Edinburgh, Edinburgh, Scotland, United Kingdom The objective of this study was to evaluate the effectiveness of Hoffmann's method of saturation-recovery snapshot FLASH (SRSF) to minimise the effect of radiofrequency (RF) pulse angle inhomogeneity in breast dynamic contrast-enhanced (DCE)-MRI at 3T. We employed computer simulation and experiment on gel phantom for this purpose. The simulation shows that Hoffmanns SRSF produces a robust saturation in the presence of expected RF inhomogeneity. The enhancement ratio data acquired broadly matches the simulation. Implementing this method may be a solution to minimise the effects of RF pulse angle inhomogeneity in DCE-MRI of the breast at 3T. 2493. Patient-Specific Calibration for Breast MRI: Breast-Coil Insertable Reference Phantom Marieke Heisen1, Bo Peng2, Abbie Marie Wood3, Devkumar Mustafi2,3, Johannes Buurman4, Gillian M. Newstead3, Gregory S. Karczmar3 1Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands; 2Biochemistry & Molecular Biology, The University of Chicago, Chicago, IL, United States; 3Radiology, The University of Chicago, Chicago, IL, United States; 4Healthcare Informatics, Philips Healthcare, Best, Netherlands A unique calibration phantom was designed for routine use in breast MRI. It was used to correct the variable flip angles in a precontrast T1-measurement, and to inspect T1 sensitivity in the clinically employed T1-weighted dynamic contrast-enhanced protocol. The flip angle correction altered the T1 estimates in breast tissue significantly. The clinical protocol demonstrated an increase in signal intensity for decreasing T1 (as expected) until a certain level, after which signal attenuation occurred. The quality of the breast images acquired with the phantom in place was found to be normal by an experienced mammographer. 2494. MR Imaging Features of Invasive Lobular Carcinoma: A Comparison with Invasive Ductal Carcinoma Sung Hun Kim1, Jae Young Byun1, Eun Suk Cha1, Hyun Sook Kim1, Jae Jeong Choi1 1Radiology, College of Medicine, the Catholic University of Korea, Seocho gu, Seoul, Korea, Republic of Invasive lobular carcinoma (ILC) is the second most common breast cancer after invasive ductal carcinoma (IDC). The incidence of ILC has continuously increased probably due to hormone replacement therapy. There were little studies to compare the imaging findings of ILC and IDC according to BI-RADS. The purposes of our study were to characterize the mammographic and MR imaing features of ILC and to compare these imaging features with those of IDC. Furthermore, the multiplicity and MRI diagnostic accuracy to detect the multiplicity apart from the index mass were determined. 2495. BOLD Imaging of Compressed Breast Hemodynamics Stefan Alexandru Carp1, Azma Mareyam1, Lawrence Wald1, David Alan Boas1 1Radiology, Massachusetts General Hospital, Charlestown, MA, United States External compression induced hemodynamic changes in the breast have recently been investigated as potential biomarkers of breast cancer. Using fast diffuse NIR spectroscopy our group has demonstrated the non-invasive estimation of breast tissue blood flow and oxygen consumption. Consequently, we have designed an integrated MRI-optical breast compression platform for simultaneous acquisition of MR and optical images. MR scans provide structural prior information for optical reconstructions, as well as hemodynamic (BOLD) images for cross-validation against optically measured deoxy-hemoglobin. We describe the MRI breast compression platform and present initial results demonstrating contrast between the BOLD signal evolution in fibro-glandular vs. adipose tissue. Gary Lee1, Patrick Goodwill1, Kevin Phuong2, Ben Inglis3, Brian Hargreaves4, Steven Conolly1,2 1Berkeley/UCSF Bioengineering Joint Graduate Group, Berkeley, CA, United States; 2Bioengineering, University of California - Berkeley, Berkeley, CA, United States; 3Henry J Wheeler, Jr. Brain Imaging Center, Berkeley, CA, United States; 4Radiology, Stanford University, Palo Alto, CA, United States DCE breast MRI is emerging as the second most common diagnostic imaging modality for breast cancer, which has ~200,000 new cases and ~40,000 deaths annually. However, breast MRI still lacks adequate specificity. Magnetic susceptibility mismatches near the breast/air interface contribute to field inhomogeneities which make frequency selective fat suppression techniques more difficult. We have developed tissue susceptibility matched pyrolytic graphite foam that is lightweight, safe for patients, and compatible with embedded RF coils. PG foams may improve frequency selective fat suppression for breast MRI and provide more robust motion suppression, which may lead to improved specificity in breast cancer diagnosis. 2497. Cactus Spines as Fiducials for MRI and Pathology Correlation of Ex-Vivo Human Lymph Nodes Mies A. Korteweg1, Jaco J.M. Zwanenburg1, Cristian Koolstra, Paul J. van Diest2, Arjen J. Witkamp3, Willem P.Th.M. Mali1, Peter R. Luijten1, Wouter B. Veldhuis1 1Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Pathology, University Medical Center Utrecht, Utrecht, Netherlands; 3Surgery, University Medical Center Utrecht, Netherlands We describe the properties and suitability of cactus spines used as fiducial markers in ex-vivo human lymph nodes for the correlation of MRI to histopathology. In 42 nodes cactus spines were inserted before scanning at 7T. Afterwards the nodes were pathologically examined. Geometric distortions, susceptibility- or pathologic examination artifacts and identification on MRI were scored. Cactus spines were readily identified both on MRI and at histopathology. No interference was noted for either analysis. It was concluded that cactus spines are suitable fiducials which aid in the accurate correlation of intranodal imaging features to histopathology. Matt Smith1, Krishna Kurpad2, Catherine Moran1, Xu Zhai1, Walter Block1,3, Sean Fain1,3 1Medical Physics, University of Wisconsin, Madison, WI, United States; 2Radiology, University of Wisconsin, Madison, WI, United States; 3Biomedical Engineering, University of Wisconsin, Madison, WI, United States Regardless of the sampling technique, the volume of interest is degraded by excited signal energy outside the FOV. With 3D non-Cartesian acquisitions, the effect is incoherent streaking with noise-like appearance. Commercial receive only breast coils require slice/slab excitation from the body coil, exciting tissue outside the FOV. A local transmit/receive breast coil based on a solenoid design is compared with a commercial receive-only coil to demonstrate that local excitation minimizes the unwanted signal energy contaminating the FOV for non-Cartesian breast MR. Measurements of contrast are higher and more consistent using a 3DPR SSFP sequence with a local transmit/receive breast coil. 2499. Adaptive 3D Radial MRI Based on Multidimensional Golden Means for Supine Breast Imaging Peter Siegler1, Rachel W.-C. Chan2, Elizabeth A. Ramsay1, Donald B. Plewes1 1Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; 2Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada Dynamic contrast-enhanced breast MRI shows a high sensitivity for breast cancer but is commonly done in prone position which complicates its use for image-aided strategies. Recently, supine unilateral breast MRI with compensation for respiratory motion was successfully implemented. However, standard Cartesian sampling has no isotropic spatial resolution, which is desirable for image-aided applications. Here, 3D projection reconstruction based on multidimensional golden means was tested for use in supine breast MRI. The technique allowed post-processed compensation for respiratory motion, which is intrinsic in a supine position of the patient, without the need to choose any motion-compensation settings prior to the scan. 2500. Towards a Microspectroscopy Catheter for Early-Stage Breast Cancer Detection Debra Strick Rivera1, Jack W. Judy2, W Gilbert Clarke2, Dixie J. Mills3, Allen C. Chu2, Mark S. Cohen2 1Neurophysics, Max Planck Institute, Leipzig, Saxony, Germany; 2University of California, Los Angeles; 3Dr. Susan Love Research Foundation Early-detection of breast cancer is unreliable, and of increased importance due to encouraging results of intraductal application of chemotherapy. We present a prototype radio-frequency transceiver for intraductal microspectroscopy, including soak-tests and heating studies. We demonstrate that the microcoil prototype is capable of resolving fat and water spectra in a sample with 5000-fold fewer spins than a state of the art matrix coil. 2501. Breast Perfusion Imaging Using Arterial Spin Labeling Misung Han1,2, Brian A. Hargreaves1, Bruce L. Daniel1, David C. Alsop3,4, Philip M. Robson, 4,5, Eric Han6, Pauline W. Worters1, Ajit Shankaranarayanan6 1Radiology, Stanford University, Stanford, CA, United States; 2Electrial Engineering, Stanford University, Stanford, CA, United States; 3Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 4Radiology, Harvard Medical School, Boston, MA, United States; 5Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School , Boston, MA, United States; 6Applied Science Lab, GE Healthcare, Menlo Park, CA, United States Malignant breast tumors induce high level angiogenesis, resulting in increased vascularity and perfusion. For breast MRI, dynamic contrast-enhanced MRI is most widely used to detect and characterize tumors; on the other hand, arterial spin labeling (ASL) technique is very challenging due to low baseline flow in breasts. Here, we show our experience in 2D breast ASL using FAIR labeling and background suppression in both volunteers and patients. With our technique, higher perfusion signal was depicted in tumor. 2502. Improved Fat Suppression with High Resolution Balanced Steady State Imaging in the Breast Dorothee Barbara Engel1, Catherine Judith Moran2, Fred Kelcz3, Stephan O. Schoenberg1, Walter Block2 1Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Mannheim, Germany; 2Department of Medical Physics, University of Wisconsin, Madison, WI, United States; 3Department of Radiology, University of Wisconsin, Madison, WI, United States While the Dynamic Contrast Enhanced (DCE) acquisition remains the centerpiece of breast MRI, both signal intensity and the depiction of lesion morphology in T2-weighted images can help to distinguish malignant versus benign lesions. With TRs on the order of seconds, T2-weighted acquisitions are generally inefficient and most often acquired with high in-plane resolution but low through plane resolution. A radial bSSFP acquisition termed 3DPR-SSFP has been shown to provide improved depiction of lesion morphology in comparison to conventional T2-weighed acquisitions. We evaluate the performance of two methods for improving fat suppression of 3DPR-SSFP while retaining the advantage of clear depiction of fine morphological details in the breast. Karl-Heinz Herrmann1, Pascal A. Baltzer, Ines Krumbein, Christian Geppert2, Werner A. Kaiser, Jürgen R. Reichenbach1 1Medical Physics Group, Department of Diagnostic and Interventional Radiology, University Hospital Jena, Jena, Thüringen, Germany; 2MR Oncology, Siemens Healthcare, Erlangen In MR Mammography pathologic vascularisation is utilized for the diagnosis of tumors. Many standard dynamic MRM protocols contain a delay of 35s, during which the contrast agent is applied, between the native scan and the following multiple post-CA scans. This injection delay can be efficiently used to acquire additional dynamic data sets with both high temporal (5.7s) and spatial resolution (0.9x0.9x1.5mm) using a 3D gradient echo view sharing sequence with stochastic trajectories (TWIST). This allows to resolve the arterial phase of the contrast agents first pass and helps to detect anomalous arterial supply vessels to suspect lesions. Lung & Mediastinum MRI Hall B Wednesday 13:30-15:30 Magdalena Zurek1, Laura Carrero-Gonzalez2,3, Selina Bucher2, Thomas Kaulisch2, Detlef Stiller2, Yannick Crémillieux1 1Université de Lyon, Laboratoire CREATIS-LRMN, Lyon, France; 2Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany; 3Universidad Complutense de Madrid, Madrid, Spain A radial ultra short-echo time (UTE) sequence has been shown to be appropriate in pulmonary imaging due to its robustness against motion and its improved image resolution. In this study, we evaluated the accuracy of edema detection using two protocols based on conventional-Cartesian and UTE radial imaging approaches. Despite degraded image quality in case of Cartesian images due to the motion, similar inflammation extent was found for both approaches. The UTE technique, applied under free-breathing conditions, will certainly prove to be quite useful in routine MR investigations applied on models of lung diseases associated with inflammation or mucous hypersecretion. 2505. Ultrashort Echo Time (UTE) MR Lung Imaging with Respiratory Motion Compensation Jiangsheng Yu1, Yiqun Xue1, Hamidreza Saligheh Rad1, Hee Kwon Song1 1Laboratory for Structural NMR Imaging, Department of Radiology,, University of Pennsylvania, Philadelphia, PA, United States Ultra-short echo time (UTE) MRI has been successfully applied to lung imaging, but so far the issue of respiratory motion during imaging the lung parenchyma has not yet been addressed. In this work, a respiratory motion-compensated UTE lung MRI technique is presented. This technique applies the golden-angle view increment strategy in conjunction with respiratory self-gating to reconstruct images at different respiratory phases to reduce respiratory motion artifacts. The in-vivo results demonstrate that lung image quality is significantly enhanced with improved visualization and delineation of lung vasculature, as well as improved SNR, as compared to conventional gradient echo images. 2506. Comparison of Lung T2* Measurements at 1.5T and 3.0T with Ultrashort Echo Time (UTE) Sequence Jiangsheng Yu1, Yiqun Xue1, Hee Kwon Song1 1University of Pennsylvania, Philadelphia, PA, United States Accurate assessments of lung T2* may be important as it has the potential to detect structural and functional changes caused by lung diseases such as emphysema, chronic bronchitis and fibrosis. While measurements have been carried out in both animals and humans at 1.5T, studies on human lung at 3T have not yet been reported. In this work, we compare T2* values in normal human lungs at 1.5T and 3.0T using an ultrashort echo time (UTE) pulse sequence. Results show the average lung T2* of 0.72 (±0.17) ms at 3.0T is considerably shorter than 2.2 (±0.43) ms at 1.5T. 2507. Time-Resolved Lung Perfusion- And Ventilation-Weighted MRI by Wavelet Analysis Grzegorz Bauman1,2, Julien Dinkel3, Michael Puderbach3, Lothar Rudi Schad2 1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 2Computer Assisted Clinical Medicine, University of Heidelberg, Mannheim, Germany; 3Department of Radiology, German Cancer Research Center, Heidelberg, Germany Non-contrast based assessment of the pulmonary function using MRI remains challenging. We propose a novel post-processing method based on the Wavelet analysis to retrieve information about pulmonary perfusion and ventilation. The method utilizes rapid acquisition of time-resolved MR-data using a 2D Steady-State Free Precession sequence implemented on a 1.5 T whole-body MR-scanner. Wavelet transform allows for a robust analysis of non-stationary physiological signals (respiratory/cardiac cycles). The aim of this study was to show feasibility of the proposed approach. 2508. Improved Visualization of Pulmonary Parenchyma Using SSFP Sequence for Dynamic MR-Studies Grzegorz Bauman1,2, Michael Deimling3, Michael Puderbach4, Lothar Rudi Schad2 1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 2Computer Assisted Clinical Medicine, University of Heidelberg, Mannheim, Germany; 3Siemens Healthcare, Erlangen, Germany; 4Department of Radiology, German Cancer Research Center, Heidelberg, Germany In lung MRI, due to the fast signal dephasing, respiratory motion and cardiac pulsation, very fast imaging sequences using short repetition times or the application of triggering techniques are required. The aim of this work was to numerically simulate and optimize the Steady-State Free Precession (SSFP) imaging scheme for dynamic studies on a 1.5 T whole-body MR-scanner. Fast imaging with the SSFP sequence using a combination of the central k-space sampling, parallel imaging, high bandwidth and minimal inter-echo sampling allowed to improve the visualization of the pulmonary tissue sufficiently for functional lung MRI. 2509. High Resolution T2 Weighted Lung Imaging with a Radial Turbo Spin-Echo Sequence Michael Völker1, Philipp Ehses1, Martin Blaimer2, Felix Breuer2, Peter Michael Jakob1,2 1Department of Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany; 2Research Center for Magnetic Resonance Bavaria (MRB), Würzburg, Germany A segmented radial Turbo Spin-Echo (rTSE) sequence was investigated towards its feasibility for high resolution lung imaging under free breathing conditions. No triggering techniques were involved to define the limits of the sequence itself. Unlike ultrafast singleshot techniques such as HASTE resolution is not intrinsically limited by the T2 signal decay while motion, especially of the beating heart, poses only a small problem in comparison with conventional Cartesian TSE. In addition, arbitrary T2 contrasts may be generated by postprocessing a single dataset allowing for the calculation of quantitative T2 maps. 2510. Proton MRI of Human Lung Using 2D Radial Acquisition at 1.5 T and 3.0 T Jascha Zapp1, Simon Konstandin1, Lothar R. Schad1 1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany MRI of the lung is challenging because of low proton density, respiratory and cardiac motion and susceptibility effects at air-tissue interfaces. A healthy volunteer was examined using a 2D radial gradient echo technique (resolution: 0.8mm x 0.8mm x 5.0mm) with conventional (full) RF pulses (TE=0.77ms) and half RF pulses (TE=0.02ms) at 1.5T and 3.0T. Average SNR in lung parenchyma resulted in an increase of 56% at 3.0T compared to 1.5T with TE=0.02ms. The result shows that SNR in proton MRI of human lung at 3.0T is superior to 1.5T when using a 2D radial sequence with ultrashort echo time. 2511. Feasibility of Using Linear Combination SSFP for Lung MRI at 3 T Atiyah Yahya1,2, Keith Wachowicz1,2, B. Gino Fallone1,2 1Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta, Canada; 2Department of Oncology, University of Alberta, Edmonton, Alberta, Canada MRI of the lungs is challenging because of the low proton density and because of the large number of air-tissue interfaces which create susceptibility gradients. Lung MRI has shown to be feasible at 3 T using the HASTE sequence with parallel imaging. In this work we examine the feasibility of applying Linear Combination SSFP (LCSSFP) for lung MRI at 3 T. Experiments were conducted on a normal volunteer and lung images were acquired with both HASTE and LCSSFP. The images acquired with LCSSFP were clearer and did not suffer from blurring compared to the HASTE images. Anna Louise Babin1,2, Catherine Cannet1, Christelle Gerard1, Clive P. Page3, Nicolau Beckmann1 1Global Imaging Group, Novartis Institutes for BioMedical Research, Basel, BS, Switzerland; 2Sackler Institute of Pulmonary Pharmacology, Kings College, London, SE1 1UL, United Kingdom; 3Sackler Institute of Pulmonary Pharmacology, King's College, London, SE1 1UL, United Kingdom Micro-CT has been shown to be useful in characterizing anatomical changes related to lung fibrosis models in rats. However, radiation doses are an issue both in the clinics and in experimental studies, and repetitive measurements are limited. In the present work, we show that proton MRI can be used to follow longitudinally in spontaneously breathing rats the development of structural changes related to lung fibrosis induced by bleomycin administration, and thus MRI represents a non-X ray based imaging alternative to study experimental fibrosis. Selina Bucher1, Michael Neumaier1, Sascha Koehler2, Birgit Jung3, Detlef Stiller1 1In-Vivo Imaging Unit, Dept. of Drug Discovery Support, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany; 2Method Development, Bruker BioSpin MRI GmbH, Ettlingen, Germany; 3Dept. of Respiratory Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, BW, Germany Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation and mucus production. Because an excess of mucus triggers infections, an efficient mucociliary clearance (MCC) is important. To detect therapy-induced changes in MCC, non-invasive imaging techniques are needed. We used 2D radial MRI and micron-sized iron-oxide particles to evaluate MCC in the rat lung, where four different iron-oxide particles yielded an attenuated MR signal. Clearance of 4.5 µm-sized particles occurred within one day, whereas smaller and larger particles were not cleared. Our results indicate a great potential for MRI with micron-sized iron-oxide particles to visualize and quantify MCC in patients. 2514. Fast and Robust T1 Mapping of the Human Lung at Different Sites Jakob Kreutner1, Ruobing Yang2, Simon Triphan1,3, Martin Blaimer3, Felix Breuer3, Peter Michael Jakob1,3 1Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany; 2University of British Columbia, Vancouver, Canada; 3Research Center Magnetic Resonance Bavaria, Würzburg, Germany Characterization of pathologic lung tissue necessitates a robust method for diagnosis. T1 relaxation times provide information about oxygen transfer in the lung. To demonstrate the robustness of the IR Snapshot FLASH sequence we repeatedly quantified T1 at different sites using a lung phantom made of several Gd-DTPA doped bottles. The results show an excellent reproducibility of the relaxation times. Penny Louise Hubbard1,2, Geoff J. M. Parker1,2, Dave Singh3, Jųrgen Vestbo3, Simon S. Young4, Eva Bondesson5, Lars E. Olsson6, Josephine H. Naish1,2 1Imaging Sciences and Biomedical Engineering, University of Manchester, Manchester, United Kingdom; 2The University of Manchester Biomedical Imaging Institute, Manchester, United Kingdom; 3Airway Pharmacology Group, School of Translational Medicine,, University Hospital of South Manchester Foundation Trust, Manchester, United Kingdom; 4AstraZeneca R & D, Charnwood, United Kingdom; 5AstraZeneca R & D, Lund, Sweden; 6AstraZeneca R & D, Mölndal, Sweden We present a regional characterisation of the ventilation-perfusion ratio using a novel two-compartment physiological model analysis of oxygen-enhanced MRI data. A preliminary analysis of subjects with chronic obstructive pulmonary disease and age-matched healthy subjects shows how changes in T1 can be related directly to physiological parameters indicative of lung function. This novel MR method is minimally-invasive and repeatable, and reveals enhanced sensitivity to the early onset of disease than more traditional global lung function measures. 2516. Physiological Modelling of Oxygen-Enhanced MRI in the Lung Josephine Helen Naish1,2, Geoff J M Parker1,2 1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University of Manchester, Manchester, United Kingdom; 2Biomedical Imaging Institute, University of Manchester, Manchester, United Kingdom We present a two-compartment model of pulmonary oxygen-enhanced MRI (OE-MRI) based on known gas exchange processes in the lung. The model relates the rate of change of oxygen partial pressure to physiological parameters describing ventilation, perfusion and blood oxygen solubility and allows quantitative V/Q maps to be extracted from OE-MRI data. Simon Triphan1, Philipp Ehses2, Martin Blaimer1, Jakob Kreutner2, Felix Breuer1, Peter Jakob, 12 1Research Center Magnetic Resonance Bavaria e.V., Würzburg, Bayern, Germany; 2Experimentelle Physik 5, Universität Würzburg, Würzburg, Bayern, Germany The quantification of T1 in the human lung at 1.5T using an Inversion Recovery Snapshot FLASH experiment was improved by employing an asymmetric radial readout scheme: By measuring k-space with golden angle radial projections with maximal echo asymmetry, echo times could be significantly reduced yielding improved signal from lung tissue. The acquisition scheme was combined with a KWIC-filter technique to reconstruct images at subsequent points in time along signal recovery, thereby achieving a higher temporal resolution compared to a cartesian measurement. The improved SNR and higher temporal resolution was used to calculate T1 maps at an increased spatial resolution.
Yogesh K. Mariappan1, Arunark Kolipaka1, Richard L. Ehman1, Kiaran P. McGee1 1Department of Radiology, Mayo Clinic, Rochester, MN, United States Previous lung magnetic resonance elastography (MRE) animal experiments have indicated that it is feasible to quantitate the shear modulus of lungs with 1H MRI with the driver in direct contact with the lungs. Here, we tested the applicability of this technique in an in situ porcine model with a noninvasive mechanical driver placed on the chest wall. Further, the feasibility of this technique to measure the change in stiffness of the lung parenchyma as a function of transpulmonary pressure was also evaluated. It was found that lung stiffness can be quantified with this setup and that shear stiffness increases with increasing transpulmonary pressure. Yogesh K. Mariappan1, Kevin J. Glaser1, Armando Manduca1, Richard L. Ehman1, Kiaran P. McGee1 1Department of Radiology, Mayo Clinic, Rochester, MN, United States Application of Magnetic Resonance Elastography within the lung is challenging because of the inherently low 1H MR signal. The additional motion-sensitizing gradients inserted into the conventional MR sequence necessary for MRE results in longer echo times, further degrading the signal from lung parenchyma. We hypothesized that with appropriate manipulations, the crusher gradients of a spin echo sequence can be used for motion detection, while maintaining a short echo time. We tested this hypothesis in healthy human volunteers and found that it is feasible to detect motion within the lungs with the imaging gradients while maintaining sufficient lung tissue signal. Alexandra Rose Morgan1,2, Geoff J.M. Parker1,2, Marietta L.J. Scott3, Tim F. Cootes1,2, Josephine H. Naish1,2 1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, The University of Manchester, Manchester, United Kingdom; 2The Biomedical Imaging Institute, The University of Manchester, Manchester, United Kingdom; 3AstraZeneca, Alderley Park, Macclesfield, United Kingdom Current diagnosis methods in chronic obstructive pulmonary disease (COPD) are not capable of examining regional pathological changes in mechanical properties. We have developed a method for investigating relative regional pulmonary compliance using proton magnetic resonance imaging (MRI). A 2D half-Fourier acquired single-shot turbo spin-echo (HASTE) sequence was optimised for lung imaging. A mesh-based group-wise affine image registration was applied to images ordered according to respiratory cycle position. Information from the registration allowed relative regional compliance measures to be extracted and mapped over the lung. Maps show differences between healthy volunteers and COPD patients and can indicate likely regions of disease. 2521. Quantification of Bleomycin Induced Lung Injury by Means of 1H Magnetic Resonance Elastography Kiaran P. McGee1, Richard L. Ehman1, Rolf D. Hubmayr2, David L. Levin1, Mary Breen3, Debora Rasmussen2, Yogesh K. Mariappan1 1Radiology, Mayo Clinic and Foundation, Rochester, MN, United States; 2Pulmonology & Critical Care, Mayo Clinic and Foundation, Rochester, MN, United States; 3College of Arts and Sciences, Boston College, Boston, MA, United States Interstitial lung disease (ILD) induced end stage fibrosis is a multi phase process that includes presence of an exudate followed by either edema clearance or organization of the space filling material and fibrosis. We have applied magnetic resonance elastography (MRE) to determine if this method can differentiate between normal and those processes associated with ILD. MRE estimates of shear modulus increased following lung injury when compared to an air-filled lung suggesting that lung injury-induced restructuring of lung parenchyma results in changes to the intrinsic mechanical properties of the lung and that these changes can be quantitated with MRE. Junichi Tokuda1, Hatsuho Mamata1, Ritu R. Gill1, Samuel Patz1, Nobuhiko Hata1, Robert E. Lenkinski2, David J. Sugarbaker3, Hiroto Hatabu1 1Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States; 2Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 3Department of Surgery, Brigham and Women's Hospital, Boston, MA, United States We demonstrate perfusion analysis of solitary pulmonary nodule based on free-breath DCE MRI. In DCE MRI studies, the kinetics of signal variation at lesions following the administration of the contrast agent is analyzed from time-intensity curve. Thus, it is crucial to measure the signal intensity at the corresponding regions in each frame in the time-series of images for accurate signal intensity curve analysis. However, the respiratory motion of the subjects during scans causes misalignment of anatomical regions among the frames resulting inaccuracy of time-intensity curve. In this paper, we compare perfusion analyses based on motion-compensated MRI data and manual measurement. Keiko Matsumoto1, Yoshiharu Ohno1, Hisanobu Koyama1, Munenobu Nogami1, Daisuke Takenaka1, Yumiko Onishi1, Nobulazu Aoyama2, Hideaki Kawamitsu2, Tsutomu Araki3, Kazuro Sugimura1 1Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; 2Division of Radiology, Kobe University Hospital, Kobe, Hyogo, Japan; 3Department of Radiology, University of Yamanashi, Japan Academic and social interest to radiation induced cancer development on CT examination is increasing in the world. Since 1997, several investigators have suggested that pulmonary MR imaging on 1.5T MR system has potential for nodule detection as substitution to CT. To the best of our knowledge, no one directly compare the capability of non-contrast-enhanced (non-CE) pulmonary MRI for pulmonary nodule detection between 1.5T and 3.0T MR systems. The purpose of this study was to prospectively and directly compare the capability of non-CE pulmonary MR imaging on 3.0T MR system for nodule detection than that on 1.5T MR system. 2524. Blood Supply and Vascularization of Lung Cancer, Studies by MRI and Optical Imaging Gregory Jacques Ramniceanu1, Erez Eyal2, Inbal Biton3, Nava Nevo2, Raanan Margalit4, Raya Eilam-Altstadter3, Hadassa Degani1 1Biological regulation, Weizmann Institute of Science, Rehovot, Israel; 2biological regulation, Weizmann Institute of Science, Rehovot, Israel; 3Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel; 4Immunology, Weizmann Institute of Science, Rehovot, Israel The lung vasculature is composed of two systems, the bronchial and the pulmonary circulations. It is still unknown which of these two circulations, or both, contribute to the feeding of lung tumors during their progression .To answer this basic we characterize the perfusion parameters and the role of angiogenesis and interstitial fluid pressure in the lung tumors using MRI and optical imaging methods. Specifically we focus on imaging interstitial fluid pressure using a slow infusion protocol of the contrast agent. 2525. DC Gated High Resolution 3D MRI of the Human Lung Under Free Breathing Stefan Weick1, Philipp Ehses2, Martin Blaimer2, F. A. Breuer2, P. M. Jakob1,2 1Department of Experimental Physics 5, University of Wuerzburg, Wuerzburg, Bavaria, Germany; 2Research Center for Magnetic Resonance Bavaria (MRB) In this work, 3D Flash examinations of the human lung were performed during free respiration using the DC signal for self-gating. Short echo times (TE) are required to provide sufficiently SNR because of the short T2* of the lung tissue. It is shown that the DC signal can be acquired after the actual imaging module still providing enough quality for respiratory gating and simultaneously providing very short echo times. The maxima and minima of the DC signal were used to define threshold values for data rejection and high resolution images were reconstructed retrospectively. Keiko Matsumoto1, Yoshiharu Ohno1, Hisanobu Koyama1, Yumiko Onishi1, Daisuke Takenaka1, Munenobu Nogami1, Nobukazu Aoyama2, Hideaki Kawamitsu2, Tsutomu Araki3, Kazuro Sugimura1 1Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; 2Division of Radiology, Kobe University Hospital, Kobe, Japan; 3Department of Radiology, University of Yamanashi, Japan MDCT has become the first imaging examination in suspected APTE patients. As well as technical advances of CT, technical advances of magnetic resonance (MR) imaging make it possible to obtain time-resolved MR angiography or perfusion MR imaging (perfusion MRI) in APTE patients. We hypothesized that quantitatively assessed pulmonary perfusion parameters from contrast-enhanced perfusion MRI have potential for disease extent assessment and have predictive capability of patient outcome in APTE patients. The aim of our study was therefore to directly compare the capability for disease severity assessment and patient outcome prediction of MDCT and MR techniques in APTE patients. 2527. Exploration of Gas Flow During High Frequency Oscillated Ventilation by 19F-Gas-MRI Janet Friedrich1, Julien Rivoire1, Alexander Wiegbert Scholz2, Maxim Terekhov1, Rainer Köbrich2, Lars Krenkel3, Claus Wagner3, Laura Maria Schreiber1 1Section of Medical Physics, Department of Diagnostic and Interventional Radiology, Johannes Gutenberg University Medical Center, Mainz, Germany; 2Department of Anesthesiology, Johannes Gutenberg University Medical Center, Mainz, Germany; 3German Aerospace Center, Göttingen, Germany To detect convective gas flow inside the large airways during high frequency oscillated ventilation (HFOV) the fluorinated contrast gas Heptafluoropropane was used for 19F-MRI. In a first study the comparison between constant flow measurements and Computational Fluid Dynamics (CFD) simulations provided a good agreement. In a following experiment oscillated flow was applied to a lung phantom consisting of ventilation bag and long pipe. The pressure wave inside the pipe was explored point-by-point and corresponding velocities were determined. With these experiments it could be shown for the first time that flow measurement during HFOV using fluorinated contrast gas is feasible. Hyperpolarized Gas Imaging Hall B Thursday 13:30-15:30 Matthew S. Fox1,2, Alexei Ouriadov1, William Dominguez-Viqueira1,3, Marcus Couch1,2, Giles E. Santyr1,3 1Imaging, Robarts Research Institute, London, Ontario, Canada; 2Physics and Astronomy Dept, University of Western Ontario, London, Ontario, Canada; 3Medical Biophysics, University of Western Ontario, London, Ontario, Canada Magnetic Resonance (MR) imaging using hyperpolarized noble gases (HNG) 3He and 129Xe provides a non-invasive approach for probing both lung function and structure. Measurement of ventilated lung volumes are useful for characterizing chronic obstructive pulmonary disease, quantifying the diffusing capacity of xenon and may be useful in measuring lung mechanics such as compliance. The objective of this work was to perform 3D MR imaging in rats under similar ventilation conditions and compare measured ventilated volumes obtained from the two gases in an effort to show that 129Xe is just as accurate as 3He which has already been validated by microCT. Talissa A. Altes1, John P. Mugler1, Isabel M. Dregely2, Stephen Ketel3, Iulian C. Ruset2,3, Eduard E. de Lange1, F William Hersman2,3, Kai Ruppert1 1Radiology, University of Virginia, Charlottesville, VA, United States; 2Physics, University of New Hampshire, Durham, NH; 3Xemed, LCC, Durham, NH The purpose of this study was to assess the feasibility and currently achievable quality of hyperpolarized xenon-129 ventilation (spin density) MRI in normal subjects (n=7) and patients with asthma (n=5), chronic obstructive pulmonary disease (COPD) (n=4), cystic fibrosis (CF) (n=1), and sickle cell disease (SCD) (n=1). As seen previously with helium, the normal subjects had homogeneous ventilation with few if any ventilation defects. Focal ventilation defects were found in all patients with obstructive lung diseases. Qualitatively the hyperpolarized xenon-129 ventilation images are similar although not identical to previously acquired hyperpolarized helium-3 ventilation images in different patients with similar disease states. Jim M. Wild1, Salma Ajraoui1, Martin H. Deppe1, Steven R. Parnell1, Helen Marshall1, James Swinscoe2, Matthew Hatton2, Juan Parra-Robles1, Rob H. Ireland1 1Academic Radiology, University of Sheffield, Sheffield, Yorkshire, United Kingdom; 2Weston Park Hopital, Sheffield, United Kingdom Combined 1H MRI of lung anatomy with hyperpolarised gas MRI of lung function has previously required acquisition of separate breath-hold exams, with separate MRI pulse sequences and dedicated RF coils, resulting in images that were not spatially registered or temporally synchronised. Here 1H anatomical and 3He ventilation MRI from human lungs were acquired in the same breath-hold using decoupled RF hardware and optimised dual acquisition MRI pulse sequences. The resulting 3He and 1H images acquired in the same breath (from volunteers and patients with lung disease), showed superior registration to those acquired in repeat breath-hold manoeuvres. Miranda Kirby1,2, Lindsay Mathew1,2, Andrew Wheatley1, David G. McCormack3, Grace Parraga1,4 1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; 2Medical Biophysics, The University of Western Ontario; 3Division of Respirology, Department of Medicine, The University of Western Ontario; 4Graduate Program in Biomedical Engineering, The University of Western Ontario Here we evaluate the associations between hyperpolarized Helium-3 Magnetic Resonance Imaging (3He MRI) longitudinal changes measured in Chronic Obstructive Pulmonary Disease (COPD) ex-smokers, with SNR and inter-observer variability. Spin density images for 15 subjects were segmented to obtain ventilation defect volume (VDV) measurements at baseline and 26 months. Inter-observer reproducibility was determined for two observers; ICC= .93, COV= 26% and r2= .78 (p<.0001). There was no significant relationship between image SNR and inter-observer variability (r=-.06, p=.75). Therefore, measurement variability is not affected by SNR and increases in VDV at follow-up may reflect COPD airway functional changes, suggestive of disease progression. Yanping Sun1, Linxi Shi1,2, Guoen Jin1, Sanaz Zhalehdoust Sani3, Justin L. Lui3, Stephen J. Krinzman4, John Mark Madison4, Kenneth R. Lutchen3, Mitchell S. Albert1 1Radiology, University of Massachusetts, Worcester, MA, United States; 2Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States; 3Biomedical Engineering, Boston University, Boston, MA, United States; 4Pulmonary, University of Massachusetts, Worcester, MA, United States We used hyperpolarized 3He MR to image subjects with asthma at two scanning sessions 45 days apart; during each session, baseline and post-methacholine scans were collected. We found that post-methacholine, defect number increased by an average of 172%. The percentage of defects that remained in the same location between imaging sessions was 75% ± 40 between baseline scans, but 96% ± 4 between post-methacholine scans. Thus, methacholine provocations in asthmatics increased defect number, but defects tended to remain in the same location from one provocation to another. Our results suggest that asthma dysfunction has an important localized component. 2533. Using Hyperpolarized 3He MRI to Evaluate Therapeutics in Cystic Fibrosis Patients Yanping Sun1, Brian O'Sullivan2, Ronn P. Walvick1,3, Austin L. Reno1, Linxi Shi1,4, Dawn Baker2, Joey Mansour1, Mitchell S. Albert1 1Radiology, University of Massachusetts, Worcester, MA, United States; 2Pediatrics, University of Massachusetts, Worcester, MA, United States; 3Biomedical Engineering, Worcester Polytechnic Institute , Worcester, MA, United States; 4Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States Cystic fibrosis (CF) is a genetic disease impairing chloride permeability in epithelial cells; CF causes thick, viscous mucus, leading to lung congestion, frequent infections, and over time, debilitating lung damage. In this study, we used HP 3He static ventilation MRI scans to assess improvement of lung ventilation in three CF patients following treatment with intravenous antibiotics, daily administration of hypertonic saline, and administration of rhDNase. In one of the subjects, there was a 25% increase in ventilation measured by HP 3He MRI following treatment, which corresponded with spirometry. The other two subjects showed no changes in 3He ventilation. Jaime Mata1, Talissa Altes1, Steve Springmeyer2, Jonathon Truwit1, Eduard de Lange1, Peter Sylvester1, John Mugler III1 1University of Virginia, Charlottesville, VA, United States; 2Spiration Inc, Redmond, WA, United States The purpose was to determine whether hyperpolarized helium-3 (HHe) ventilation and diffusion MR imaging can detect changes in lung function and microstructure resulting from bronchial valve placement. One subject was imaged with HHe, pre and 6-month post IBV placement. Physiological changes of the lung were observed and quantified. In conclusion, HHe MR imaging appears to provide a safe, non-invasive method for measuring functional and structural changes in the lungs after IBV placement.
James D. Quirk1, Barbara A. Lutey2, Jason C. Woods1,3, Alexander L. Sukstanskii1, Mark S. Conradi, 1,3, Mario Castro2, David S. Gierada1, Dmitriy A. Yablonskiy1,3 1Radiology, Washington University School of Medicine, St. Louis, MO, United States; 2Internal Medicine, Washington University School of Medicine, St. Louis, MO, United States; 3Physics, Washington University, St. Louis, MO, United States In vivo lung morphometry with hyperpolarized helium-3 MRI is a sensitive method for detecting early emphysema and provides a unique insight into changes in the acinar microstructure. We utilized this technique to measure acinar geometrical parameters in 30 smokers and 5 healthy volunteers. Our results support the view that early emphysema progresses through dilation of alveolar ducts with retraction of alveolar walls. We also detected significant disease heterogeneity across the lung and suggest that these patterns can provide important insights into disease phenotypes and are valuable for monitoring disease progression and regression. Helen Marshall1, Salma Ajraoui1, James M. Wild1 1Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom The study of ventilation dynamics with hyperpolarised 3He requires a fast imaging sequence to capture the flow of contrast into the lungs. Radial acquisition, among other sequences, has previously been demonstrated for this purpose. However, images from a standard radial acquisition are constrained to a fixed resolution determined at the acquisition stage. Here golden angle radial sampling was used to image the inhalation of hyperpolarised 3He and compared to a standard, sequential radial acquisition. Golden angle radial imaging enabled reconstruction of the dynamic dataset at any chosen spatio-temporal resolution, providing improved visualisation of the initial stages of inhalation. 2537. On the Relationship Between 3He ADC and Lung Morphometrical Parameters Alexander L. Sukstanskii1, James D. Quirk1, Jason C. Woods1,2, David S. Gierada1, Barbara A. Lutey3, Mark S. Conradi2, Dmitriy A. Yablonskiy1,2 1Radiology, Washington University, St. Louis, Misssouri, United States; 2Physics, Washington University, St. Louis, MO, United States; 3Internal Medicine, Washington University, St. Louis, MO, United States The apparent diffusion coefficient (ADC) of hyperpolarized 3He gas in lungs increases in emphysema and can serve as a biomarker of the disease progression. It is not clear, however, how ADC relates to lung microstructure. In the present communication, using 3He-based in vivo lung morphometry technique, we demonstrate that ADC and a standard histological parameter mean chord length (Lm) reflect lung microstructure parameters in different ways. As a result, a there is no unique relationship between ADC and Lm. At the same time, 3He-based lung morphometry allows quantification of the lung microstructure in terms of Lm, surface-to-volume ratio and other standard histological parameters. 2538. Modelling Non-Gaussian 3He Diffusion Signal Behaviour Using a Fractional Dynamics Approach Juan Parra-Robles1, Salma Ajraoui1, Jim M. Wild1 1University of Sheffield, Sheffield, United Kingdom Diffusion of 3He gas in the lung has been shown to deviate from Gaussian behaviour. Cylinder model and diffusional kurtosis have been previously used to quantify non-Gaussian signals. In this work the diffusion stretched-exponential model is used as a new approach to model the non-Gaussian behaviour. The results obtained demonstrate that the anomalous diffusion stretched-exponential model fits well the behaviour of the 3He lung MR signal. This model can potentially provide valuable information about lung microstructure at different length scales. Juan Parra-Robles1, Salma Ajraoui1, Martin H. Deppe1, Steven R. Parnell1, Jim M. Wild1 1Unit of Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom In this work, the limits of validity of physical basis of a model of 3He MR lung diffusion are investigated experimentally in simple geometric models. The experimental results have highlighted limitations of the cylinder model. Breakdown of the Gaussian phase approximation was experimentally demonstrated for gradient strengths commonly used in lung ADC experiments, as the localized diffusion regime is approached. The physical assumptions of the cylinder model are only valid if the localized diffusion regime and its neighboring intermediate regimes are avoided. 2540. Exact Results for Diffusion Weighted MR on Branched Structures Niels Buhl1,2, Sune Jespersen2 1Physics and Astronomy, University of Aarhus, Aarhus, Denmark; 2CFIN, University of Aarhus, Aarhus, Denmark Diffusion-weighted MRI (DWI) employing long diffusion times can provide information on connectivity and topology in branching systems. We present an exact result for the diffusion propagator on a large class of metric networks (graphs), and subsequently derive an analytical expression for the signal attenuation in a PGSE diffusion experiment. We apply these results to a simple acinar model and demonstrate the sensitivity of DWI to an increasing number of collateral pathways. Chengbo Wang1, Talissa A. Altes1, John P. Mugler, III1,2, Eduard E. de Lange1, Kai Ruppert1, William F. Hersman3,4, Isabel M. Dregely3, Iulian Ruset, 3,4, Stephen Ketel4, Sylvia Verbanck5 1Radiology, University of Virginia, Charlottesville, VA, United States; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 3Physics, University of New Hampshire, Durham, NH, United States; 4Xemed LLC, Durham, NH, United States; 5Respiratory Division, University Hospital UZ Brussel, Brussels, Belgium Long-time-scale 3He and 129Xe diffusion was measured in human lungs and was found to strongly depend on the diffusion times. The computer simulation agreed well with experimental measurements using only the intra-acinar structure, suggesting that long-time-scale ADC was dominated by intra-acinar structure in the lung. The importance of the intra-acinar structure and collateral channels may vary with varying parameters such as tag wavelength. Intra- and interacinar collateral channels can lead to considerable relative ADC increases, suggesting that noble gas diffusion may be sensitive to mild degree of collateral channels which may occur in early smoking related lung disease. 2542. Imaging Morphometric Changes in the Human Pulmonary Acinus in Vivo Via 3He Diffusion MRI Adam J. Hajari1,2, James D. Quirk2, Dmitriy A. Yablonskiy, 12, Alex L. Sukstanskii2, Mark S. Conradi1,2, Jason C. Woods, 12 1Physics, Washington University, St. Louis, MO, United States; 2Radiology, Washington University, St. Louis, MO, United States 3He diffusion MRI is used to study in-vivo morphological changes at the alveolar level in human lungs. We employ a 6 b-value diffusion pulse sequence for imaging at three different levels of inspiration. An established mathematical model relating signal attenuation from the diffusion gradients to alveolar geometry is fit voxel-by-voxel to the diffusion images to determine average alveolar depth and alveolar duct radii at each of the three lung volumes. On average a 50% increase in lung volume led to a 9% increase in average alveolar duct radius and a 22% decrease in average alveolar depth. Chengbo Wang1, John P. Mugler, III1,2, Eduard E. de Lange1, Kai Ruppert1, William F. Hersman3,4, Isabel M. Dregely3, Iulian Ruset, 3,4, Stephen Ketel4, Talissa A. Altes1 1Radiology, University of Virginia, Charlottesville, VA, United States; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 3Physics, University of New Hampshire, Durham, NH, United States; 4Xemed LLC, Durham, NH, United States Regional ADC maps of hyperpolarized 129Xe in human lungs measured over both short and long time scales and with identical spatial registration during a single breath hold were acquired in 5 human subjects. Measured 129Xe ADC values were about 10% of the corresponding previously reported 3He ADC values for both time scales, similar to the expected difference of 16% due to the differences in diffusivity of the gases. The current SNR of 129Xe MRI is sufficient for diffusion MRI, and 129Xe diffusion MRI has been performed in healthy subjects and subjects with lung disease. Chengbo Wang1, Talissa A. Altes1, John P. Mugler, III1,2, Eduard E. de Lange1, Robert M. Strieter3, Yun M. Shim3,4 1Radiology, University of Virginia, Charlottesville, VA, United States; 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 3Medicine, University of Virginia, Charlottesville, VA, United States; 4Pulmonary and Critical Care, University of Virginia, Charlottesville, VA, United States Short-time-scale (STS) and long-time-scale (LTS) helium-3 ADC values were measured in the lungs of smokers and found to be moderately correlated with %predFEV1, but poorly correlated with exercise stress testing, possibly because non-respiratory factors may significantly affect exercise capacity. STS helium-3 ADC values did not correlate with %DLCO while LTS ADC values were moderately correlated with %DLCO. These results support an association between lung microstructural alterations caused by cigarette smoking and functional changes in FEV1 and %DLCO, and suggest that LTS ADC is more sensitive than STS ADC in detecting early pulmonary injury. Suryanarayanan Sivaram Kaushik1, Zackary I. Cleveland1, Gary P. Cofer1, Gregory Metz2, Denise Beaver2, John Nouls1, Monica Kraft3, Jan Wolber4, H Page McAdams2, Bastiaan Driehuys1 1Center for In-Vivo Microscopy, Duke University Medical Center, Durham, NC, United States; 2Radiology, Duke University Medical Center, Durham, NC, United States; 3Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, NC, United States; 4GE Healthcare, Amersham, United Kingdom Apparent diffusion coefficient (ADC) MRI using hyperpolarized 3He has been established as a radiation free alternative to Computerized Tomography in evaluating pulmonary microstructure, but its use is limited in biomedical research applications due to its high cost and low availability. Recently, the success of HP 129Xe in showing sensitivity to alveolar microstructure changes in animals suggests that 129Xe, which is cheaper and more readily available, is also suitable for ADC measurements. Here, we discuss 129Xe ADC imaging results from healthy volunteers and COPD patients with early stage emphysema and show that 129Xe ADC imaging can successfully discriminate the two groups. Masaru Ishii1,2, Kiarash Emami2, John M. Woodburn2, Stephen J. Kadlecek2, Elaine Chia2, Jianliang Zhu3, Stephen Pickup2, Yi Xin2, Rahim R. Rizi2 1Department of Otolaryngology, Johns Hopkins University, Baltimore, MD, United States; 2Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 3Department of Surgery, University of Pennsylvania, Philadelphia, PA, United States The sensitivity of two HP 3He MRI-based measurements, gas diffusivity and ventilation, to elastase-induced changes in a murine model of emphysema is studied in this work. The motivation is primarily the increasing interest in assessments of pulmonary disease models and assessments of therapeutic interventions in transgenic murine disease models, which require that functional and structural lung imaging techniques be translated to a smaller scale. We present a predictive model for calculating the probability that a section of lung originated from a diseased animal. Matthew S. Fox1,2, Alexei Ouriadov1, William Dominguez-Viqueira1,3, Marcus Couch1,2, Giles E. Santyr1,3 1Imaging, Robarts Research Institute, London, Ontario, Canada; 2Physics and Astronomy Dept, University of Western Ontario, London, Ontario, Canada; 3Medical Biophysics, University of Western Ontario, London, Ontario, Canada Hyperpolarized 129Xe is a novel gaseous contrast agent which also dissolves in the lung parenchyma and blood compartments, offering an interesting palette of potential biomarkers of pulmonary disease. 129Xe signals from the dissolved compartments have different chemical shifts and can be selectively saturated and allowed to recovery as a function of delay time as in the chemically selective saturation recovery (CSSR) technique. We collected CSSR data and 3D volumes from rat lungs in-vivo and explore both the Butler and Mansson model for estimations of surface to volume ratio, diffusing capacity and tissue transit time. 2548. Anisotropic Nature of 3He Gas Diffusion in Mice Lungs Emir Osmanagic1, Alexander L. Sukstanskii2, Mark S. Conradi3, James D. Quirk2, Dmitriy A. Yablonskiy2 1Electrical and Systems Engineering, Washington University, St. Louis, Misssouri, United States; 2Radiology, Washington University, St. Louis, Misssouri, United States; 3Physics, Washington University, St. Louis, MO, United States Diffusion-attenuated MR signal of 3He gas in lungs demonstrate non-mono-exponential dependence on b-value. It was previously suggested that such behavior is a result of microscopically anisotropic but macroscopically isotropic nature of lung microstructure: diffusion in each airway is anisotropic, while distribution of airway axes directions is isotropic. Hypothetically such non-mono-exponential dependence would also be present in a system of multiple spherical compartments (mimicking alveoli) with a variety of sizes. Herein, we used experiments with three consecutive bipolar gradient pulses with orthogonal and parallel gradient orientations to discriminate between such two systems. Our result confirmed microscopically anisotropic hypothesis. Emir Osmanagic1,2, Alexander L. Sukstanskii3, James D. Quirk3, Jason C. Woods3,4, Mark S. Conradi4, Dmitriy A. Yablonskiy3,5 1Electrical and Systems Engineering, Washington University, St. Louis, Misssouri, United States; 2Radiology, Washington University, St. Louis, MO, United States; 3Radiology, Washington University, St. Louis, Misssouri, United States; 4Physics, Washington University, St. Louis, MO, United States; 5Physics, Washington University, St. Louis, Misssouri, United States Lung morphometry technique with hyperpolarized 3He allows quantification of lung geometrical parameters such as mean chord length Lm, surface-to-volume ratio S/V and density of alveoli. It was demonstrated that in humans, it provides results similar to direct morphological measurements. Two important modifications, however, are required to adopt this technique for studying lung microstructure in small animals reduction in diffusion time and modification of theoretical relationship between diffusion MR signal and lung microstructural parameters. Herein we provided such modifications and demonstrated that measurements obtained with lung morphometry with hyperpolarized 3He MRI in mice are in agreement with literature data. Jelena Pesic1, Frank Risse1, Simon Young2, Jim Britt2, Ignacio Rodriguez3, Lars E. Olsson1 1DECS Imaging and Antibodies, AstraZeneca R&D, Mölndal, Sweden; 2Bioscience, AstraZeneca R&D, Charnwood, United Kingdom; 3Instituto de Estudios Biofuncionales, Universidad Complutense, Madrid, Spain HP 3He ADC imaging was used to assess the effect of a glucocorticoid budesonide on inflammation in ovalbumin challenged rats. Four groups of animals were investigated: controls, vehicle treated, low and high dose budesonide treated. The ADC was significantly smaller in the vehicle group, indicating reduced airspace in the alveoli, possibly due to plasma leakage into the alveoli. Treatment with budesonide decreased inflammation as shown by significantly reduced eosinophil counts and higher ADC values than in the vehicle group. 2551. Hyperpolarized Xenon-129 Dissolved-Phase Signal Dependence on Flip Angle and TR Kai Ruppert1, Jaime F. Mata1, Isabel M. Dregely2, Talissa A. Altes1, G Wilson Miller1, Stephen Ketel3, Jeff Ketel3, Iulian C. Ruset, 2,3, F William Hersman2,3, John P. Mugler, III1 1Radiology, University of Virginia, Charlottesville, VA, United States; 2Physics, University of New Hampshire, Durham, NH, United States; 3Xemed, LLC, Durham, NH, United States Due to the large chemical shift difference between hyperpolarized Xe129 (HXe129) dissolved in lung tissue and in the alveolar air spaces it is feasible to image both compartments simultaneously, appearing side-by-side in the image, by using a suitable imaging bandwidth. The weighting of the dissolved-phase contrast can be shifted from exchange-site dominant to blood-pool dominant through an adjustment of the TR/FA combination of the acquisition. Thereby it is feasible to monitor and quantify the HXe129 gas transport processes throughout the pulmonary and cardiovascular system up to the aortic arch. 2552. Hyperpolarized Xenon-129 Dissolved-Phase Signal Dependence on the Echo Time Kai Ruppert1, Jaime F. Mata1, Isabel M. Dregely2, Talissa A. Altes1, G Wilson Miller1, Stephen Ketel3, Jeff Ketel3, Iulian C. Ruset3, F William Hersman2, John P. Mugler, III1 1Radiology, University of Virginia, Charlottesville, VA, United States; 2Physics, University of New Hampshire, Durham, NH, United States; 3Xemed, LLC, Durham, NH, United States Due to the large chemical shift difference between hyperpolarized Xe129 (HXe129) dissolved in lung tissue and in the alveolar air spaces it is feasible to image both compartments simultaneously, appearing side-by-side in the image, by using a suitable imaging bandwidth. By varying the TE of the image acquisition it appears to be feasible to extract additional information about the regional distribution of the dissolved-phase sub-compartments, which might be strongly affected by pulmonary interstitial or vascular diseases. Prelimary results in alive and post mortem rabbits are presented. 2553. Signal Dynamics During Dissolved-Phase Hyperpolarized 129Xe Radial MR Imaging of Human Lungs Zackary I. Cleveland1,2, Gary P. Cofer1,2, Gregory Metz3, Denise Beaver3, John Nouls1,2, Sivaram Kaushik1,2, Monica Kraft3, Jan Wolber4, Kevin T. Kelly5, H Page McAdams2, Bastiaan Driehuys1,2 1Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States; 2Radiology, Duke University Medical Center, Durham, NC, United States; 3Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, NC, United States; 4GE Healthcare, Amersham, United Kingdom; 5Radiation Oncology, Duke University Medical Center, Durham, NC, United States It is now possible to directly image HP 129Xe dissolved in pulmonary gas exchange tissues of humans. Dissolved image intensity is dominated by relaxation, RF attenuation, and diffusive replenishment of dissolved 129Xe magnetization, which are influenced by pulmonary structure and physiology. Here, we develop a closed-form mathematical model of dissolved 129Xe magnetization dynamics during 3D radial imaging. Model predictions agree well with observations and can be used in image optimization. Because radial images acquire k-zero in each view, the model also allows dynamic information to be extracted from raw image data and may provide insights into global lung physiology. Isabel Dregely1, Kai Ruppert2, Jaime F. Mata2, Talissa A. Altes2, Jeff Ketel3, Iulian C. Ruset3, Steve Ketel3, G. Wilson Miller2, John P. Mugler III2, F. W. Hersman1,3 1Physics, University of New Hampshire, Durham, NH, United States; 2Radiology, University of Virginia, Charlottesville, VA, United States; 3Xemed LLC, Durham, NH, United States The purpose of this work is to investigate the ability of 3D multiple exchange time xenon polarization transfer contrast (MXTC) MRI to detect changes in lung microstructure following the instillation of elastase into a rabbit lung. 3D MXTC is an extension of the XTC technique, which allows the calculation of the regional septal wall thickness and the tissue-to-alveolar-volume ratio. We observed an increase in the global mean of tissue thickness and relative tissue volume and identified regions of abnormal lung microstructure in the rabbit lung post-elastase instillation most likely due to an initial severe inflammatory response. Isabel Dregely1, Iulian C. Ruset2, Jeff Ketel2, Steve Ketel2, Jaime F. Mata3, Talissa A. Altes3, G. Wilson Miller3, John P. Mugler III3, F. W. Hersman1,2, Kai Ruppert3 1Physics, University of New Hampshire, Durham, NH, United States; 2Xemed LLC, Durham, NH, United States; 3Radiology, University of Virginia, Charlottesville, VA, United States We investigated the response of rabbit lungs to different lung ventilation volumes using 3D multiple-exchange time xenon polarization transfer contrast (MXTC) MRI. From the subsequently fitted exchange time constant of the xenon exchange between alveolar air spaces and the surrounding septal walls, the tissue thickness can be calculated. The long exchange time limit allows calculation of the tissue-to-alveolar volume ratio. We observed increased tissue-to-alveolar volume ratio in posterior partitions and decreased septal wall thickness in anterior partitions at low lung volumes. At high ventilation volumes these differences disappear. 2556. Theoretical Model for XTC (Xenon Transfer Contrast) Experiments with Hyperpolarized 129Xe Mirko I. Hrovat1, Iga Muradian2, Eric Frederick3, James P. Butler4, Hiroto Hatabu2, Samuel Patz2 1Mirtech, Inc., Brockton, MA, United States; 2Radiology, Brigham and Women's Hospital, Boston, MA, United States; 3Dept. of Physics, University of Masachusetts at Lowell, Lowell, MA, United States; 4Harvard School of Public Health, Boston, MA, United States A theoretical model is presented to understand the XTC experiment with hyperpolarized 129Xe for arbitrary flip angle. The model is flexible in that different dissolved state diffusion models may be incorporated. The model also illustrates fundamental differences between CSSR and XTC experiments. It is clear that no single exchange time value dominates the time evolution of the XTC signal. It is demonstrated that the XTC90 experiment (employing 90° flips instead of 180°) should generate results similar to CSSR experiments. 2557. Lung Inflation State Dominates Over Intrapulmonary PO2 Regarding T2* of 3He in Human Lungs Martin H. Deppe1, Salma Ajraoui1, Helen Marshall1, Jim M. Wild1 1Academic Radiology, University of Sheffield, Sheffield, Yorkshire, United Kingdom This work investigates the influence of O2 on the T2* of hyperpolarized 3He in human lungs. To separate the effect of O2 from the known lung inflation dependence, T2* maps were obtained at expiration and full inspiration, both at baseline breathing air and after 4 min of pure O2. It is found that the effect of lung inflation dominates over any potential O2 effect, which is proposed to be due to a combination of motional narrowing and the fact that 3He is distributed over the whole alveolus, while 1H spins are confined to the interfaces, where susceptibility gradients are strongest. 2558. Motion-Corrected PO2 Mapping in Human Lungs Using Hyperpolarized Xe-129 MRI G. Wilson Miller1, John P. Mugler III1, Talissa A. Altes1, Isabel Dregely2, Iulian Ruset3, Steve Ketel3, Jeff Ketel3, William F. Hersman2,3, Kai Ruppert1 1Radiology, University of Virginia, Charlottesville, VA, United States; 2Physics, University of New Hampshire, Durham, NH; 3Xemed LLC, Durham, NH Lung pO2 mapping using hyperpolarized Xe-129 was performed in 6 healthy volunteers and 4 disease patients. An image registration algorithm was used to correct for subject motion during the breath hold acquisition. John C. Nouls1, Manuel Fanarjian2, Bastiaan Driehuys1,3 1Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States; 2Biomedical Engineering, Duke University, Durham, NC, United States; 3Radiology, Duke University Medical Center We present a constant-volume small-animal ventilator that offers precise control of gas delivery, permits high-resolution hyperpolarized gas imaging, and captures the exhaled mixture containing 3He or 129Xe for recycling. The captured gas is compressed by a piston and stored in a cylinder to be sent for re-purification. The same ventilator can ventilate different small animals, simply by changing flow constrictors. The ventilator is inexpensive to duplicate and only uses off-the shelf components. By recapturing exhaled gas, it alleviates some of the costs associated with HP gas imaging. 2560. Hyperpolarized Noble Gas MR Imaging SNR Comparison Between 73.5 MT and 3 T in Rat Lung William Dominguez-Viqueira1,2, Matthew S. Fox, 1,3, Giles E. Santyr2,4 1Imaging Laboratories, Robarts Research Institute, London, Ontario, Canada; 2Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 3Department of Physics and Astronomy, University of Western Ontario, London, Ontario, Canada; 4Department of Medical Imaging, University of Western Ontario, London, Ontario, Canada The maximum SNR in Hyperpolarized Noble Gas (HNG) MR imaging of rodent lung is expected to be at high fields (>3T). However, SNR improvements of up to 300% have been demonstrated in rat lung at 73.5mT using Litz-wire coils. In this work the SNR for HNG MRI of rat lung was investigated theoretically and in vivo, using multi-turn Litz-wire coils at 73.5mT and compared to images obtained at 3T using 129Xe and 3He. The use of Litz-wire coils significantly reduces the advantage (from factor ten to a factor of two) of using high fields for HNG imaging of rat lungs. 2561. Quantitative Assessment of Alveolar Recruitment with Hyperpolarized Gas MRI Kiarash Emami1, Masaru Ishii2, Stephen J. Kadlecek1, Jianliang Zhu3, Stephen Pickup1, Yi Xin1, Puttisarn Mongkolwisetwara1, Harrilla Profka1, Rahim R. Rizi1 1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Otolaryngology, Johns Hopkins University, Baltimore, MD, United States; 3Department of Surgery, University of Pennsylvania, Philadelphia, PA, United States This study evaluates the preliminary use of HP gas diffusion MRI to assess alveolar recruitment dynamics in a healthy rat model. After a period of ventilation at zero positive end-expiratory pressure (PEEP), recruitment was studied at elevated PEEP and constant tidal volume. After recruitment, it was found that regional ADC values initially diminished and consistently recovered with the removal of elevated PEEP. It is therefore proposed that before recruitment, accumulated alveolar collapse causes the over-extension of active alveoli (high ADC); after recruitment, the fixed tidal volume is shared by the greater number of recruited alveoli (corresponding to decreased ADC). 2562. Alveolar Gas Diffusion MRI as a Function of Pulmonary Pressure Kiarash Emami1, Stephen J. Kadlecek1, Yi Xin1, Puttisarn Mongkolwisetwara1, Harrilla Profka1, Stephen Pickup1, Jianliang Zhu2, Masaru Ishii3, Rahim R. Rizi1 1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Surgery, University of Pennsylvania, Philadelphia, PA, United States; 3Department of Otolaryngology, Johns Hopkins University, Baltimore, MD, United States In this work, we evaluate the use of HP gas ADC measurements to assess the positive end-expiratory pressure (PEEP) dependence of alveolar recruitment in a healthy rat model. By maintaining a constant tidal volume, ADC can be decoupled from volume dependence and thus considered a measurement of average alveolar size. In general, it was found that higher ADC values correspond with large PEEP. Additionally, at any given PEEP, the end-inhale ADC value is larger than the end-exhale ADC value, supporting the theory that in low-recruitment conditions (large numbers of collapsed alveoli), active alveoli are over-inflated (yielding high ADC). 2563. Quantitative Assessment of Idiopathic Pulmonary Fibrosis with Hyperpolarized Gas MRI Michael J. Stephen1, Kiarash Emami2, John M. Woodburn2, Elaine Chia2, Stephen J. Kadlecek2, Jianliang Zhu3, Masaru Ishii4, Milton Rossman1, Benjamin Pullinger2, Stephen Pickup2, Rahim R. Rizi2 1Department of Pulmonary and Critical Care, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 3Department of Surgery, VA Medical Center, Philadelphia, PA, United States; 4Department of Otolaryngology, Johns Hopkins University, Baltimore, MD, United States This study demonstrates the first attempt to use hyperpolarized gas MR images of lung ventilation and apparent diffusion (ADC) in an animal model of interstitial lung disease. The efficacy of hyperpolarized 3He MRI metrics in assessing idiopathic pulmonary fibrosis (IPF) was evaluated in a bleomycin rat model. Results showed that fractional ventilation 3 weeks after bleomycin administration was significantly lower than in the control animals, and ADC measurements followed similar trends. Hyperpolarized gas MRI is a promising diagnostic for IPF and an improvement over current diagnostics in its regional sensitivity and benignancy. Angelos Kyriazis1,2, Ignacio Rodriguez1,2, Jose-Manuel Perez-Sanchez3, Lars E. Olsson4, Jesus Ruiz-Cabello1,2 1Universidad Complutense de Madrid, Instituto de Estudios Biofuncionales, Madrid, Spain; 2CIBER de Enfermedades Respiratorias, Spain; 3Orsay and Kremlin-Bicetre, U2R2M, Paris, France; 4DECS Imaging, AstraZeneca R&D, Mölndal, Sweden A method to estimate regional lung volume over time based on spin-density 3He images is presented. Combining this with the tracheal pressure, regional volume over pressure is appraised. The static ROI are the left and the right lobe of the lung. Physiological parameters were calculated for the two ROI and for the whole lung. The method is proven reproducible because the measurements of the ROI of the same animal as well as the measurements of different animals agreed satisfactorily. The method may differentiate not only healthy from diseased animals but also healthy from diseased areas of the lung. 2565. In Vivo Comparison of 2D and 3D T2* in the Rat Lung Using Hyperpolarized Helium-3 MRI at 1.5 T Kyle Hill1,2, José-Manuel Pérez-Sįnchez2, Roberta Santarelli2, Mathieu Sarracanie2, Pascal Hagot2, Marlies Friese2, Xavier Maītre2, Luc Darrasse2 1University of Oxford, Oxford, Oxfordshire, United Kingdom; 2Imagerie par Résonance Magnétique Médicale et Multimodalité (UMR 8081), Univ Paris-Sud, CNRS, Paris, Le Kremlin-Bicźtre, France The T¬2* of hyperpolarized helium-3 in the lungs has shown promise in characterizing lung microstructure due to its sensitivity to local gradients caused by gas-tissue interfaces, whose abundance per unit volume changes with lung inflation and pathological modification. Despite the lungs three-dimensional structure, most measurements of helium-3 T¬2* have been performed using projection imaging which neglects the complex microstructures effects. This work uses five rats in vivo to compare the T2* in a projection image with 3D imaging and shows that 3D is necessary to detect statistically different local phenomena that may not be apparent in projection imaging. Marlies Elly Joy Friese1, Kimble R. Dunster, 12, Gary J. Cowin1, Deming Wang1, Graham Galloway1, John Fraser3,4, Andreas Schibler, 4,5 1Centre for Magnetic Resonance, The University of Queensland, Brisbane, Queensland, Australia; 2Medical Engineering Research Facility,, Queensland University of Technology, Brisbane, Queensland, Australia; 3Paediatric Intensive Care Unit,, Mater Childrens Hospital, Brisbane, Queensland, Australia; 4Critical Care Research Group, The Prince Charles Hospital, Brisbane, Queensland, Australia; 5Paediatric Intensive Care Unit, Mater Childrens Hospital, Brisbane, Queensland, Australia Gravity-dependent ventilation distribution was investigated in using both hyperpolarised helium-3 magnetic resonance imaging (HP3He MRI) and electrical impedance tomography (EIT). Time averaged EIT data and HP3HeMRI images of apnoea showed ventilation distribution in rats to be gravity dependent, whereas regional filling characteristics are dependent on anatomy. HP3He MRI and EIT data agree where they can be compared. HP3He MRI provides data on real geometry which EIT cannot as EIT tomograms are reconstructed to a circular image. Dynamic imaging of the breathing cycle with HP3He is still needed to make a full comparison of the two methods. 2567. Respiratory Impedance in a Mouse Model of Asthma Using Hyperpolarized 3He MR Imaging Suryanarayanan Sivaram Kaushik1, John Nouls1, Erin Potts2, Zackary Cleveland1, W Michael Foster2, Bastiaan Driehuys1 1Center for In-Vivo Microscopy, Duke University Medical Center, Durham, NC, United States; 2Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, NC, United States The broncho-constriction and inflammation associated with asthma contributes to increased airway impedance. This impedance is typically measured using global respiratory mechanics techniques such as FlexiVent. However, the time course of broncho-constriction can also be directly visualized using hyperpolarized (HP) 3He MRI. This imaging-based technique provides a time-dependent method for quantifying central airway impedance and may be useful to assess the regional contributions to globally measured impedance. Here, we discuss the method we used in obtaining the upper airway impedance during a Methacholine (Mch) challenge, in a mouse model of asthma. 2568. Relaxation of Hyperpolarized 129Xe in a Flexible Gas Reservoir Harald E. Möller1,2, Zackary I. Cleveland2, Laurence W. Hedlund2, Bastiaan Driehuys2 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States In experiments involving repeated deliveries of hyperpolarized (HP) gas, the delivered magnetization is not constant due to unavoidable relaxation during HP gas storage. Moreover, the spin-lattice relaxation time, T1R, inside flexible plastic bags, which often serve as HP gas reservoirs, is not constant. The change of T1R of HP 129Xe in a deflating bag can be quantitatively described by a model based on simple spherical geometry and the kinetic theory of gases to account for relaxation mechanisms in the bulk gas and on the container walls. Results might be used for optimizing signal utilization and improving the point-spread function. 2569. Hyperpolarized 3He Image Feature Analysis in Asthmatics Nicholas James Tustison1, Talissa A. Altes2, Gang Song1, Eduard E. de Lange2, John P. Mugler III2, James C. Gee1 1Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Radiology, University of Virginia, Charlottesville, VA, United States We analyze features extracted from hyperpolarized helium-3 ventilation images in asthmatic and normal populations and quantify their discriminatory abilities in characterizing clinical diagnosis relative to spirometric features. 2570. Retrospective Bias Correction of Hyperpolarized 3He MRI of the Lung Nicholas James Tustison1, Talissa A. Altes2, G. Wilson Miller2, Eduard E. de Lange2, John P. Mugler III2, James C. Gee1 1Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Radiology, University of Virginia, Charlottesville, VA, United States We present an open source bias correction algorithm based on the popular N3 algorithm and demonstrate its superior performance for nonuniform intensity correction in hyperpolarized helium-3 lung images. Lindsay Mathew1,2, Usaf Aladl1, Aaron Fenster1,2, Grace Parraga1,2 1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; 2Medical Biophysics, The University of Western Ontario, London, Ontario, Canada Hyperpolarized 3He MRI has shown promise as a treatment planning tool for lung cancer. Current barriers to the application of this technology include a lack of accurate image registration techniques. Registration of longitudinally acquired 3He MRI scans and 3He MRI to CT will allow for both detection of regional changes in lung function, and determination of ventilation defect pathology. In this study accuracy and variability of 3He MRI registration techniques were evaluated from a dataset consisting of subjects scanned longitudinally at our center. The Fiducial Localization Error and Fiducial Registration Error were evaluated as metrics of registration accuracy and precision. Jionghan Dai1, Eric Peterson2, James H. Holmes3, Sean B. Fain1,4 1Medical Physics, University of Wisconsin - Madison, Madison, WI, United States; 2Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States; 3Applied Science Lab, GE Healthcare, Madison, WI, United States; 4Radiology, University of Wisconsin - Madison, Madison, WI, United States This work seeks to provide a quantitative regional measure of gas retention in the lung. A 3D multi-echo projection acquisition is used, accompanied with an iterative HYPR reconstruction to provide a time resolved 3D image series. Post exhalation images are used to generate quantitative maps of gas retention. To summarize, this work presents potential new methods to characterize the gas retention under forced exhalation using hyperpolarized noble gas MRI. 2573. B1 Self-Calibration for Artifact Removal in Radial Hyperpolarised 3He Lung Imaging Helen Marshall1, Salma Ajraoui1, Martin Deppe1, James M. Wild1 1Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom In hyperpolarised 3He lung MRI the transverse signal decays with each RF excitation, imposing a k-space filter on the acquired data. For radially acquired data this filter causes streaking, angular shading and loss of spatial resolution in the images. Radial acquisition samples the centre of k-space with every projection, so tracking the signal decay. The inverse of this decay function was used to retrospectively compensate the data leading to improved image quality. The average flip angle per slice was calculated from the radial data and found to correspond well with conventional flip angle maps providing a means of B1 self-calibration. Kun Qing1, Grady Wilson Miller2, John Philip Mugler, 12 1Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 2Department of Radiology, University of Virginia, Charlottesville, VA, United States A low-flip-angle, phase-based method for calibrating the transmitter voltage for hyperpolarized gas MRI has been presented in previous studies. This work introduces two optimized versions of the phase-based method, and evaluates their performance in the presence of B0 and B1 inhomogeneities compared to that for an amplitude-based method. Results show that the accuracy of all three methods is affected by significant B1 inhomogeneity; for significant B0 inhomogeneity, the amplitude-based method is robust while the phase-based methods are very sensitive, particularly at relatively low flip angles. Julien Rivoire1, Maxin Terekhov1, Laura Maria Schreiber1 1Department of Diagnostic and Interventional Radiology, Section of Medical Physics, Johannes Gutenberg University Medical Center, Mainz, Germany To employ the scanners software computational capabilities and to simulate the complete measurement process without using expensive hyperpolarized gas, we developed the dedicated 1H MRI acquisition protocol using variable flip angle pulse sequence to simulate hyperpolarized magnetization decay. The protocol was used to study the effect of different space sampling ordering on images acquired with parallel acquisition techniques. Via the calculation of point-spread-function, the effects of the trajectories were quantitatively compared. 2576. Hyperpolarized Steady-State Free Precession with Variable Flip Angles (BSSFP-VFA) Martin H. Deppe1, Jim M. Wild1 1Academic Radiology, University of Sheffield, Sheffield, Yorkshire, United Kingdom In imaging of hyperpolarized nuclei, balanced Steady-State Free Precession (bSSFP) sequences present a high SNR alternative to the most commonly used Spoiled Gradient Echo (SPGR) sequences. Because hyperpolarized nuclei are not at thermal equilibrium, the longitudinal magnetization does not recover during an imaging experiment, but decays to a negligible value with T1. This work presents analytical expressions for variable flip angle schedules that maintain constant transverse magnetization, optimizing the effective k-space filter imposed by decay of hyperpolarization, and hence reducing image blurring. The validity of the obtained expression is demonstrated in phantom experiments. Mineyuki Hattori1, Takashi Hiraga2, Morio Murayama3, Norio Ohtake3 1Photonics, AIST, Tsukuba, Ibaraki, Japan; 2Photonics, AIST, Ikeda, Osaka, Japan; 3Toyoko Kagaku Co., Ltd., Kawasaki, Kanagawa, Japan A compact flow-through-type apparatus for the high-efficiency continuous production of hyperpolarized 129Xe using line-narrowed diode lasers and an optimized cell for obtaining a higher rubidium vapor concentration at a higher temperature (~220 oC) was developed. 2578. McConnell-Bloch Modeling of HyperCEST with Xenon Biosensors Richard Matthew Ramirez1, Todd K. Stevens1, Monica A. Smith2, David E. Wemmer1, Alexander Pines1 1Department of Chemistry, University of California, Berkeley, Berkeley, CA, United States; 2Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA, United States The McConnell-Bloch equations were modified to account for the use of hyperpolarized xenon, and then applied to fit experimental data obtained from hyperCEST experiments in which Xe exchanges into and out of a supramolecular host. A variety of physical parameters were tested and rate constants for the reversible exchange were determined, which are important in determining the amount of contrast generated from these agents. 2579. Metastability Exchange Optical Pumping of 3He at 1.5T for a In-Situ Polariser guilhem Collier1, Anna Nikiel1, Tadeusz Palasz1, Bartek Glowacz1, Mateusz Suchanek2, Zbigniew Olejniczak3, Tomasz Dohnalik1 1M. Smoluchowski Institute of Physics, Jagiellonian University, Krakow, Malopolska, Poland; 2Department of Physics, Agricultural University, Krakow, Poland; 3Institute of Nuclear Physics, Polish Academy of Sciences, Krakow The feasibility of building an in situ high field polariser of 3He using the Metastability Exchange Optical Pumping (MEOP) technique is studying here. The first results obtained with different closed cells of 3He show the possibility to produce hyperpolarised gas up to 30% at 267 mbar and 67% at 32 mbar with a volume nagnetization production never obtained yet. 2580. Pressure Dependent Signal Enhancement in Hyper-CEST Wolfgang Kilian1, Lorenz Mitschang1, Christian Freund2, Andreas Schlundt2 1Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany; 2Leibnizinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany The so called hyper-CEST method promises tremendous potential on molecule-specific MR imaging using hyperpolarized 129Xe caged in functionalized cryptophane cages. Here we present a model which allows for an optimization of the hyper-CEST sensitivity in biosensor applications, by variation of the xenon concentration in the solution. To evaluate the model we have performed hyper-CEST measurements on samples with 5 μM and 0.5 μM biosensor concentrations and varied the dissolved xenon concentration. This comparison shows that 50 nM biosensor concentrations should be detectable within a volume of 1 ml with high sensitivity. Hepato-Biliary & Liver Hall B Monday 14:00-16:00 Benjamin Leporq1, Hélčne Ratiney1, Sophie Cavassila1, Frank Pilleul2, Olivier Beuf1 1Université de Lyon, Creatis-LRMN, CNRS UMR 5220, Inserm U630, INSA-Lyon, Université Lyon 1, Villeurbanne, France; 2Université de Lyon, Creatis-LRMN, CNRS UMR 5220, Inserm U630, INSA-Lyon, Université Lyon 1, Hospices Civils de Lyon, Lyon, France In the past decade, the incidence increase of obesity, diabetes and lipid metabolism disorders involved an epidemic increase of Non-Alcoholic Fatty Liver Diseases (NAFLD) in the occidental population. Because NAFLD can evolve into Non-Alcoholic Steato-Hepatitis (NASH) and may lead to liver fibrosis up to cirrhosis, a clinical follow-up of NAFLD would be very valuable. This work investigated fat content quantification error using different models based on multiple gradient echo imaging and presents some computer simulations, phantom study and examples of in-vivo application. Multiple gradient echo acquisitions with two different flip angles associated with a model correcting for T1 saturation and T2* decay appears to be a simple but effective non-invasive method available on all clinical systems to monitor patients with chronic liver diseases. 2582. Improvements in Hepatic Stiffness Assessment with 3-D/3-Axis MR Elastography Meng Yin1, Kevin J. Glaser1, Jun Chen1, Jayant A. Talwalkar2, Armando Manduca1, Richard L. Ehman1 1Department of Radiology, Mayo Clinic, Rochester, MN, United States; 2Division of Gastroenterology, Mayo Clinic, Rochester, MN, United States One advantage of liver MR elastography (MRE) over biopsy or ultrasound-based transient elastography is its ability to reduce sampling errors by measuring liver stiffness over a large portion of the liver. While existing 2-D or localized approaches yield valid results in a substantial part of the volume, a full 3-D/3-axis wave analysis is required for valid measurements of stiffness throughout the entire liver. This investigation compares a 2-D and a 3-D approach for liver MRE and demonstrates that 3-D MRE analysis improves the homogeneity of hepatic stiffness estimates. Anand Arvind Joshi1, H Harry Hu2, Michael Goran3, Richard Leahy2, Arthur Toga1, Krishna Nayak2 1Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, United States; 2Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles; 3Keck School of Medicine, University of Southern California, Los Angeles, CA Obesity continues to be a worldwide epidemic. Accurate quantification of subcutaneous and visceral adipose tissue depot volumes and the degree fat infiltration in the liver, the pancreas, skeletal muscle, and the kidneys, are important endpoints in determining the efficacy of therapeutic and interventional measures against obesity. For example, in longitudinal studies, measures are taken at multiple time points in each subject to determine the effects of diet, exercise, lifestyle modifications, and surgery, on fat quantity and distribution. In this work, we present an automated atlas-based tool for performing 3D volume registration and segmentation of abdominal adipose tissue depots and organs. David John Lomas1, Richard T. Black1, Andrew J. Patterson1, Kieren G. Hollingsworth1, Susan Davies2, Graeme J. Alexander3, Mike E. Allison3, Neville V. Jamieson4, Alex E. Gimson3, Raaj K. Praseedom4, Chris J. Watson4 1Radiology, University of Cambridge & Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; 2Pathology, University of Cambridge & Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; 3Hepatology, University of Cambridge & Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom; 4Surgery, University of Cambridge & Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom The results of rapid MRI based measurement of donor graft steatosis immediately prior to orthotopic liver transplantation in 49 patients were correlated with surgical and histopathology estimates, first week graft performance and 3 and 12 month outcomes. MR measurements correlated significantly with the other steatosis estimates but did not correlate with early serum performance markers. Both MRI and pathology estimates indicated significantly increased graft steatosis in those grafts failing at 3 months but not at 12 months. Such MRI based measurements may be a valuable tool for further investigating the impact of graft steatosis on transplant outcomes. 2585. Effect of Intravenous Gadolinium on Estimation of Liver Stiffness with MR Elastography Sudhakar Kundapur Venkatesh1, Lynette Li San Teo1, Bertrand Wei Leng Ang1, Richard L. Ehman2 1Diagnostic Imaging, National University Health System, Singapore, Singapore; 2Radiology, Mayo Clinic, Rochester, MN, United States MR Elastography is currently the most accurate non-invasive technique for assessment of liver fibrosis. In this study, we investigated whether administration of gadolinium for routine MRI studies affects the stiffness values estimated. Our study results show that intravenous gadolinium does not affect stiffness values estimation and diagnostic performance of MRE for detection of liver fibrosis. Sudhakar Kundapur Venkatesh1, Lynette Li San Teo1, Bertrand Wei Leng Ang1, Seng Gee Lim2, Aileen Wee3 1Diagnostic Imaging, National University Health System, Singapore, Singapore; 2Gastroenterology and Hepatology, National University Health System, Singapore, Singapore; 3Pathology, National University Health System, Singapore, Singapore Liver biopsy is the gold standard for diagnosis of liver fibrosis, however has related risks and costs. A non-invasive marker of liver fibrosis is therefore desirable. Currently MRE and DWI are most promising tests for detection of liver fibrosis without the use of gadolinium based contrast agents. We performed a study to compare the performance of DWI and MRE for detection of liver fibrosis. Our study shows that MRE is more accurate than DWI for detection of all grades of fibrosis and in particular clinically significant fibrosis. 2587. 7T Human Liver Imaging Using Microstrip Surface Coil Yong Pang1, Bing Wu2, Chunsheng Wang2, Daniel Vigneron2,3, Xiaoliang Zhang2,3 1Radiology and Biomedical imaging, University of California San Francisco, San Francisco, CA , United States; 2Radiology and Biomedical imaging, University of California San Francisco, San Francisco, CA, United States; 3 UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco & Berkeley, CA, United States MRI can provide clinically-valuable images for hepatic diseases and has become the most accurate noninvasive method in evaluating liver lesions. With the development of high and ultrahigh field MRI, liver images may be acquired within breath-hold period using very short TE, essentially reducing scanning time and motion artifacts. However, B1 variation can cause significant problems at high field. In this work, T1 weighted human liver images are acquired using a fast gradient echo sequence and a λ/2 microstrip surface coil on GE whole body 7T scanner. Preliminary data demonstrates the feasibility of human liver imaging at 7 Tesla. 2588. Assessment of Chemical Exchange Saturation Transfer Effects in Liver Tissue at 7T Kejia Cai1, Mohammad Haris1, Anup Singh1, Santosh Gaddam1, Dania Daye1, Kalli Grasley1, Gerald Zsido II1, Hari Hariharan1, Ravinder Reddy1 1CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States The objective of the present study was to determine the chemical exchange saturation transfer (CEST) effects of water signal in normal and pathological liver samples on 7T MR clinical scanner, ex-vivo. In all liver tissue samples, the z-spectra showed a dip around ~2.75ppm downfield to the bulk water resonance, suggestive of exchangeable proton at this frequency. The pathological tissues showed significantly higher CEST contrast compared to normal. We are hypothesizing that the formation of liver fibrosis in various disease conditions may be expressing metabolites with exchanging groups resonating at the observed CEST frequency. Jeroen Cornelis Siero1, Marielle E. Philippens2, Arjan Willem Simonetti3, Johannes Marinus Hoogduin1, Peter R. Luijten4 1Brain Division, University Medical Center Utrecht, Utrecht, Netherlands; 2Radiotherapy, University Medical Center Utrecht; 3Philips Healthcare, Best, Netherlands; 4Radiology, University Medical Center Utrecht, Utrecht, Netherlands The potential of cost function guided shimming was shown at 3T for finding optimal shim fields that minimize B0 inhomogeneities on a user-defined region of interest while confining the B0 inhomogeneities outside this ROI. Experiments and simulations using the hybrid shimming approach show the possibility to control frequency selective fat suppression in abdomen and pelvic imaging while maintaining good B0 homogeneity in the region of interest. 2590. Reduction in Dielectric Shading in Liver on Clinical 3T Parallel Transmission MR System Trevor Andrews1, Jimmy S. Ghostine2, Jay V. Gonyea2, George M. Ebert2, Steven P. Braff3, Christopher G. Filippi3 1Philps Healthcare, Cleveland, OH, United States; 2Radiology, Fletcher Allen Health Care-UVM, Burlington, VT, United States; 3Radiology, Fletcher Allen Health Care-University of Vermont School of Medicine, Burlington, VT, United States Dielectric shading artifacts impair image quality for body applications at 3T and hamper clinical acceptance of 3T body imaging. Parallel radiofrequency (RF) excitation, an application of parallel imaging to transmission, at 3T, reduces dielectric shading by adjustment of RF transmission signals enabling RF shimming There is the added benefit of more uniform specific absorption ratio (SAR), and shorter acquisition times. Our purpose was to quantitatively validate a novel acquisition method for reducing dielectric shading using parallel transmission techniques in clinical 3T abdominal MRI. In most cases, shading artifact was nearly eliminated, and with B1 shimming this was significantly lower.
2591. Continuously Moving Table MR Imaging at 3T: A Comparison to 1.5T Ute Ariane Ludwig1, Maxim Zaitsev1, Sandra Huff1 1Department of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany Since the introduction of continuously moving table (CMT) imaging, metastases screening can easily performed in the whole body on clinical routine scanners. In this abstract, we want to demonstrate the feasibility of CMT techniques at higher field strengths. Clinical relevant imaging sequences have been adapted for imaging at 3T and evaluated on volunteers. Signal-to-noise ratio and contrast-to noise ratio have been compared to 1.5T. Future studies will combine CMT protocols for metastases screening with other MR modalities like perfusion imaging or spectroscopy, which benefit from the signal increase at higher field strengths. 2592. Flip Angle Optimization with Hepatobiliary Contrast Agents at 3T Sharon Lisa D'Souza1, Alex P. Frydrychowicz1, Karl K. Vigen1, Scott K. Nagle1, Scott B. Reeder2 1Radiology, University of Wisconsin, Madison, WI, United States; 2Radiology, Medical Physics, Biomedical Engineering, and Medicine, University of Wisconsin, Madison, WI, United States Gadolinium based contrast agents Gd-EOB-DTPA and Gd-BOPTA have hepatobiliary excretion and tremendous utility for liver lesion characterization and biliary imaging with T1 weighted imaging. Unfortunately, most T1 weighted sequences are not optimized for maximizing CNR in delayed phase hepatobiliary imaging. The purpose of this study was to perform flip angle optimization at 3.0T for delayed hepatobiliary phase imaging as part of a cross-over study comparing Gd-EOB-DTPA and Gd-BOPTA. Data show that imaging at 40-45° FA with 0.05mmol/kg Gd-EOB-DTPA at 20 minutes and 20-25° FA with 0.1mmol/kg Gd-BOPTA provides optimal CNR behavior to visualize the liver and bile ducts. Jose Ulloa1, Simone Stahl2, Carsten Liess1, Jonathan Bright3, Angela McDermott2, Neil Woodhouse1, Jane Halliday1, Arvind Parmar1, Guy Healing2, Gerry Kenna2, Andrew Holmes1, Hervé Barjat1, John Waterton1, Paul Hockings1 1Translational Sciences, Astrazeneca, Macclesfield, Cheshire, United Kingdom; 2Safety Assessment, Astrazeneca, Macclesfield, Cheshire, United Kingdom; 3Discovery Statistics, Astrazeneca, Macclesfield, Cheshire, United Kingdom Cholestasis is an important mechanism that can result in drug induced liver injury, a recurrent cause of attrition of new drug candidates. In rats, transporters Oatp1 and Mrp2 mediate liver uptake and clearance of gadoxetate, a hepatobiliary contrast agent used to characterise focal liver lesions. Estradiol-17β D-glucuronide (E217G) induces acute but transient cholestasis in rats through impairment of Mrp2 and Bsep function. The aim of this work was to assess whether characterisation of the kinetics of gadoxetate excretion can detect transient cholestasis induced by E217G. Results suggest this method can be used to investigate inhibition of transporters mediating biliary excretion. 2594. 3D-Liver Perfusion MR Imaging with MS-325 Blood Pool Contrast Agent to Evaluate Liver Fibrosis Benjamin Leporq1, Olivier Beuf1, Denis Grenier1, Frank Pilleul2 1Université de Lyon, Creatis-LRMN, CNRS UMR 5220, Inserm U630, INSA-Lyon, Université Lyon 1, Villeurbanne, France; 2Université de Lyon, Creatis-LRMN, CNRS UMR 5220, Inserm U630, INSA-Lyon, Université Lyon 1, Hospices Civils de Lyon, Lyon, France Liver fibrosis is an important cause of mortality and morbidity in patients with chronic liver. A non invasive technique to perform an early detection and a clinical follow-up of liver fibrosis is still needed. The objectives of this study was to evaluate estimated-perfusion parameters based on 1.5T-MR dynamic acquisition with the MS-325 paramagnetic blood pool agent for liver fibrosis diagnosis in comparison with histological findings. Dynamic 3D MRI was performed with a continuous free-breathing acquisition followed by a rigid-images registration. A 5-parameters dual input one compartment model was used to estimate quantitative perfusion parameters. Sixteen patients with chronic liver diseases were prospectively enrolled. Hepatic Perfusion Index and portal blood flow were found relevant parameters to discriminate between F2, F3 and F4 METAVIR stages (p<0.03). Mean transit time and total blood flow between F2, F3 and F4 stages were significantly different (p<0.05). Arterial blood flow allowed only to separate F2, F3, F4 with F0 and F1 stages (p<0.03). High molecular weight of MS-325 complex appears well suited to evaluate liver fibrosis. Matthew J. Kuhn1, Howard A. Rowley2, Cesare Colosimo3, Michael V. knopp4, Kenneth R. Maravilla5, Zoran Rumboldt6 1Radiology, University of Illinois at Peoria, Peoria, IL, United States; 2Radiology, University of Wisconsin, Madison, WI, United States; 3Radiology, University of the Sacred Heart, Rome, Italy; 4Radiology, Ohio State University, Columbus, OH, United States; 5Radiology and Surgery, University of Washington, Seattle, WA, United States; 6Radiology, Medical University of South Carolina, Charleston, SC, United States Safety results from 5 prospective, randomized, intraindividual crossover comparison studies of gadobenate dimeglumine with other gadolinium agents for magnetic resonance imaging (MRI) of the central nervous system (CNS) are reviewed. The overall rate of adverse events in these studies was 6.0%. The type and rate of adverse events was similar after gadobenate dimeglumine and the comparator agents with no significant differences noted between agents in any study. 2596. The Hepatic Uptake of Gd-EOB-DTPA Is Strongly Correlated with the Uptake of Gd-BOPTA Olof Dahlqvist Leinhard1,2, Nils Dahlström1,2, Per Sandström3, Johan Kihlberg4, Torkel Brismar5, Örjan Smedby1,2, Peter Lundberg, 2,6 1Faculty of Health Sciences/IMH, Linköping University, Linköping, Sweden; 2Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; 3Dep. of Surgery, Linköping University Hospital; 4Radiology, Linköping University Hospital; 5Karolinska University Hospital, Stockholm, Sweden; 6Radiation Physics, Linköping University Hospital In this study quantitative measurements of the hepatic uptake of the liver-specific contrast agents Gd-EOB-DTPA and Gd-BOPTA were analyzed using a simple pharmacokinetic model in a group of 10 healthy subjects. A significant correlation was found in a pairwise comparison of the uptake of the two contrast agents. Andrew Brian Gill1, Lorenzo Mannelli1, Peter Beddy1, Richard T. Black1, Ilse Joubert1, Andrew N. Priest1, Martin J. Graves1, David J. Lomas1 1Dept of Radiology, University of Cambridge & Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom This study reports hepatic perfusion measurements made with DCE-MRI at 3T, performed so as to allow analysis using a dual-input kinetic model which separates perfusion components from the hepatic artery and portal vein. DCE data acquisition had a single-heartbeat time resolution and employed a dual saturation-recovery sequence to sample high [Gd] in the blood near-simultaneously with low [Gd] in the liver parenchyma. Mean results for total perfusion (69 ± 24 ml/min/100ml) and arterial fraction (16 ± 7 %) from 7 healthy volunteers were in line with those reported by other groups collecting data at 1.5T. Hiroyoshi Isoda1, Kotaro Shimada, Tomohisa Okada, Shigeki Arizono, Toshiya Shibata, Kaori Togashi 1Diagnostic Imaging and Nuclear Medicine, Kyoto University, Kyoto, Japan To study whether shortening of acquisition time for selective hepatic artery visualization is feasible without image quality deterioration by adopting two-dimensional (2D) parallel imaging (PI) and short tau inversion recovery (STIR) methods. Shortening of the acquisition time for selective hepatic artery visualization was feasible without deterioration of the image quality by combination of 2D-PI and STIR methods. It will facilitate using non-contrast-enhanced MRA in clinical practice. Bo Xu1,2, Pascal Spincemaille2, Beatriu Reig2, Fei Sun3, Martin R. Prince2, Yi Wang, 2,3 1Department of Biomedical Engineering, Cornell University , Ithaca, NY, United States; 2Department of Radiology, Weill Cornell Medical College, New York, NY, United States; 3Department of Biomedical Engineering, Cornell University, Ithaca, NY, United States In this work, high temporal resolution 4D dynamic contrast enhanced liver MR imaging is achieved using a stack of spirals trajectory and sliding window reconstruction in healthy volunteers. This allows the detection and characterization of liver lesions in the arterial and later phases without the need for accurate contrast bolus timing. Additionally, a retrospective selection of the optimal arterial phase is possible and the determination of hepatic artery anatomical variants can be done with increased diagnostic confidence. Kengo Yoshimitsu1, Tomoyuki Okuaki2, Shutaro Saiki2, Marc van Cauteren2 1Radiology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan; 2Philips Medical Systems, Tokyo, Japan Newly developed mFFE can provide consistent fat fraction regardless of T2* or T1 alteration of the liver tissue as compared to conventional dFFE, and therefore is particularly useful in evaluation of steatosis in chronic hepatitis C or non-alcoholic steatohepatitis patients, in whom considerable amount of iron may also acculmulate in the liver. Maria Filomena Santarelli1,2, Nicola Martini2, Vincenzo Positano, 12, Alessia Pepe2, Daniele De Marchi2, Luigi Landini, 1,3, Massimo Lombardi2 1Institute of Clinical Physiology, National Research Council (CNR), Pisa, Italy; 2Tuscany Foundation "G. Monasterio", Pisa, Italy; 3Information Engineering, EIT, University of Pisa, Pisa, Italy A method is suggested, based on a SWI approach, that increases the contrast between tissues of different susceptivity, in liver T2* multi-echo gradient-echo images. 2602. Assessment of Liver Iron Overload by Combining Fast T1-Mapping and T2*-Mapping Christian Kremser1, Benjamin Henninger1, Stefan Rauch1, Heinz Zoller2, Wolfgang Vogel2, Werner Jaschke1, Michael Schocke1 1Dept. of Radiology, Innsbruck Medical University, Innsbruck, Tyrol, Austria; 2Department of Internal Medicine II, Innsbruck Medical University, Innsbruck, Tyrol, Austria The assessment of liver iron overload by means of magnetic resonance imaging is usually based on the quantification of T2* values. It was the purpose of this study to investigate if a combination of T2* values and T1 values, obtained with a fast T1 mapping technique, could be beneficial for diagnosis. 2603. Whole Liver T1,T2, and T2* Relaxation Mapping Using Echo Planar Imaging Caroline L. Hoad1, Alexander G. Gardener1, Ji-Young Lim1, Carolyn Costigan2, Robin C. Spiller3, Penny A. Gowland1, Luca Marciani3, Guru P. Aithal3, Susan T. Francis1 1School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Brain and Body Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 3Nottingham Digestive Diseases Centre, NIHR Biomedical Research Unit, University Hospitals NHS Trust, Nottingham, Nottinghamshire, United Kingdom T1, T2 and T2* relaxation maps of the whole liver of chronic liver disease patients were generated using respiratory triggered IR-SE-EPI, SE-EPI and GE-EPI datasets respectively. These maps were used to generate voxel-by-voxel histograms of the liver tissue, the central peak data of the histogram being predominately from bulk tissue (excluding vessels). This method of analysis provided a robust result, with minimal variation in the peak data when the shape of the mask was altered. A significant spread in measured peak relaxation times is found in patients with chronic liver disease. 2604. Measuring T2 in the Liver. a Comparison Between 1H Spectroscopy and SE-EPI Caroline L. Hoad1, Mary Stephenson1, Ji-Young Lim1, Alexander G. Gardener1, Carolyn Costigan2, Robin C. Spiller3, Penny A. Gowland1, Luca Marciani3, Guru P. Aithal3, Susan T. Francis1 1School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Brain and Body Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 3Nottingham Digestive Diseases Centre, NIHR Biomedical Research Unit, University Hospitals NHS Trust, Nottingham, Nottinghamshire, United Kingdom Relaxation time T2 was measured in liver water tissue of 18 chronic liver disease patients using multiple TE MRS and SE-EPI T2 mapping. There was good agreement between T2 measured using MRS and the mean T2 measured across the liver maps (including blood vessels), however peak (mode) T2 data from the EPI maps (bulk tissue only) consistently measured a shorter T2 compared to the MRS data, suggesting the MRS data tissue T2 contained some components from blood. There was considerable variation in T2 of the liver of patients with chronic liver disease possibly reflecting differences in iron content and liver fibrosis. Patrick Hawkins1, Numan C. Balci2, Sharon C. Forrest3, Frank Burton4, Samer Alkaade4, Thomas Perkins5, William H. Perman1 1Radiology, Saint Louis University School of Medicine, St. Louis, MO, United States; 2Radiology, Saint Louis University, St. Louis, MO, United States; 3Department of Radiology, Saint Louis University Hospital, St. Louis, MO, United States; 4Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, United States; 5Philips Healthcare, Cleveland, OH, United States Currently, secretin stimulation is utilized in MRCP Cambridge classification of chronic pancreatitis. Our study intends to correlate pre- and post-secretin pancreas perfusion with a more precise classification of chronic pancreatitis. Fast 3D dynamic contrast-enhanced MR perfusion scans were performed on 12 subjects with suspected chronic pancreatitis using a 3D T1 weighted turbo field echo pulse sequence. Comparison of the perfusion values between Cambridge type 3 and type 1 subjects, with normal exocrine function demonstrate a significant difference in regional and average arterial to tissue wash-in and wash-out rates. Conclusion: Contrast-enhanced MRI shows promise as a staging technique for chronic pancreatitis. Yongming Dai1, Daoying Gen2, Jiani Hu3, E.M. Haacke3 1Siemens Ltd China, Healthcare, Magnetic Resonance Imaging, Shanghai, China; 2Fudan University affiliated Huashan Hospital, Shanghai, China; 3Wayne State University, United States In this study, susceptibility weighted imaging has been extended from human brain to abdomen for iron deposition research of hepatic diseases. From the inital result, susceptibility weighted imaging could correlate the degree of hepatic iron overloaded of patients with their clinical examination results well. It seems that susceptibility weighted imaging will be a promising method alternative to conventional T2, T2star methods for iron deposition research. Dania Daye1, Kejia Cai2, Mohammad Haris2, Anup Singh2, Santosh Gaddam2, Rebecca Wells3,4, Emma Furth, Ravinder Reddy2 1Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 3Department of Medicine, University of Pennsylvania, Philadelphia, PA; 4Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States It has been previously shown that T1ρ weighted MR imaging has significant potential to provide for a non-invasive assessment of liver disease, specifically in fibrosis. In T1ρ weighted imaging, nuclear spins are locked with a radiofrequency locking field, yielding a longitudinal relaxation time (T1ρ) in the rotating frame. By varying the strength of the locking field (B1), it is possible to make the T1ρ relaxation time changes sensitive to different contrast mechanisms in tissues. Here, we show that that T1 ρ dispersion technique has significant potential to differentiate between different liver pathologies as well al further characterize certain pathologies, such as fibrosis. azza abdelrahim ahmed1, Taigang He2, Dudley Pennell2, David Firmin2 1CMR, imperial college london, London, Kensignton and Chelsea, United Kingdom; 2Imperial college london Attempts were made in measuring ultra-short T2*(<1ms) for accurate assessment of iron in the liver of patients with thalassemia major. A new sequence was developed by minimizing duration of RF pulse and shortening the ramp times and duration of field gradients. The sequence tested in phantom involved an initial echo time was reduced to 0.8ms and echo spacing to 0.6ms. For liver imaging, an echo spacing of 1.9ms was used. The developed sequence was later compared with conventional one. Results show a feasibility of measuring ultra-short T2* values in phantoms and in liver of patients using the improved sequence. 2609. Clinical Application for Cirrhosis with Susceptibility Weighted Imaging Yongming Dai1, Daoying Gen2, Wei Cheng3, E.M. Haacke4 1Siemens Ltd China, Healthcare, Magnetic Resonance Imaging, Shanghai, China; 2Fudan University affiliated Huashan Hospital; 3The Third Military Medical University affiliated SouthWest hospital; 4Wayne State University, United States In this study we extended clinical application for hepatic disease (Cirrhosis)with susceptibility weighted imaging (SWI). The results showed promising future for SWI application in human abdomen. Bahman Kasmai1, Paul Napier Malcolm1, Andoni Paul Toms1, Andrew Brian Gill2 1Radiology, Norfolk & Norwich University Hospitals NHS Trust, Norwich, Norfolk, United Kingdom; 2Radiology, Papworth Hospital NHS Foundation Trust, Cambridge, Cambridgeshire The aim of this work was to develop a software tool for validation, evaluation and integrity checks of in-house and commercial MRI iron overload systems. A windows-based software application, called SOFGEN, written in C# and based on Microsoft .NET framework generates a sets of fully Dicom compliant images from a set of user supplied parameters and decay model, for testing of Dicom compliant MRI T2(*) assessment software. The SOFGEN generated phantoms were successfully used to evaluate a number of in-house developed T2(*) assessment software and is available free via email request to authors. Catherine D. G. Hines1, Mary J. Lindstrom2, Scott B. Reeder1,3 1Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; 2Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI, United States; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States Blood flow and fasting status are recognized sources of variability in MRE measurements, and their impact on the repeatability of MRE is evaluated. MRE stiffness values and flow through the superior mesenteric vein were measured in twelve healthy volunteers in fasted and fed states, and the sequences were repeated five weeks later. No significant differences between fasted/fed state stiffness values and no correlation between values and measured flow are seen. Overall, volunteers scanned in a known fasted or fed state provide very repeatable MRE stiffness values, where the standard deviation of one MRE exam is 8.5% or 9.0% for fasted and fed states, respectively. 2612. Three-Dimensional MRCP with Reduced RF Power Deposition John P. Mugler, III1, Wilhelm Horger2, Berthold Kiefer2 1Radiology, University of Virginia, Charlottesville, VA, United States; 2Siemens Healthcare, Erlangen, Germany This work explored two approaches for reducing the RF power deposition of MRCP imaging based on a turbo-spin-echo pulse sequence. An adiabatic T2 preparation applied just before the excitation RF pulse, or a very long first echo spacing, combined with partial-Fourier acquisition permitted power deposition to be reduced by 25%-40% compared to that for a standard MRCP pulse sequence, while providing image quality comparable to that for the standard method. These methods will be valuable for addressing power-deposition limitations of MRCP at 3T, and will permit more consistent MRCP image quality to be achieved. 2613. T2-Weighted Body Imaging with PROPELLER Using Parallel Imaging with Across Blade Calibration James H. Holmes1, Philip J. Beatty2, Scott B. Reeder3,4, Zhiqiang Li5, Reed F. Busse1, Ajeetkumar Gaddipati6, Jean H. Brittain1 1Applied Science Laboratory, GE Healthcare, Madison, WI, United States; 2Applied Science Laboratory, GE Healthcare, Menlo Park, CA; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States; 4Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 5GE Healthcare, Phoenix, AZ; 6GE Healthcare, Waukesha, WI, United States This work demonstrates the application of a shared calibration scheme for autocalibrated parallel imaging to enable greater blade acceleration for abdominal PROPELLER. The shared calibration method uses external calibration data as well as a small amount of internal calibration data per blade. The technique is shown to improve robustness to motion for free-breathing T2-weighted abdominal body imaging. Results were found to compare favorably to respiratory-gated Cartesian exams suggesting that the PROPELLER approach may allow robust imaging in individuals where respiratory gating is not effective. Tomohiro Nakayama1, Takashi Yoshiura1, Yukihisa Takayama1, Eiki Nagao1, Tsuyoshi Tajima1, Akihiro Nishie1, Yoshiki Asayama1, Kousei Ishigami1, Daisuke Kakihara1, Daisuke Okamoto1, Hiroshi Honda1, Tomoyuki Okuaki2 1Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; 2Philips Electronics Japan Motion-sensitized driven-equilibrium (MSDE) preparation was added to a balanced SSFP MRCP sequence in order to suppress disturbing high signal intensities from flowing blood in vessels. We performed a volunteer study to determine optimal VENC value for the evaluation of biliary systems. We found the optimum VENC values to be 3 or 5cm/s with best suppression of relative vessel signals to bile ducts. At a lower VENC value (1cm/s), signal of bile duct was reduced likely due to minimal biliary flow. Higher VENC values (> 7cm/s) resulted in failure of vessel signal suppression. Gregory James Wilson1,2, George R. Oliveira2, Jeffrey Harold Maki, 2,3 1MR Clinical Science, Philips Healthcare, Cleveland, OH, United States; 2Radiology, University of Washington, Seattle, WA, United States; 3Radiology, Puget Sound VA HCS, Seattle, WA, United States Black-blood (BB) T2-weighted (T2w) imaging can provide increased liver lesion conspicuity over standard bright-blood T2w imaging. The sequence evaluated here uses respiratory navigator-triggering and a motion-sensitized driven equilibrium (MSDE) pre-pulse with a multi-slice turbo spin echo (TSE) readout. This sequence provides BB T2w images with high TSE image quality and without EPI distortions. In this study, various motion-sensitizing gradient directions and strengths were evaluated. 2616. Single Breath-Hold High Spatial Resolution Abdominal Imaging and T2* Mapping at 7.0 T Matthias Alexander Dieringer1,2, Fabian Hezel1, Wolfgang Renz, 1,3, Philipp Boyé, 12, Bernd Ittermann, 1,4, Frank Seifert, 1,4, Tomasz Lindel, 1,4, Thoralf Niendorf1,2 1Berlin Ultrahigh Field Facility, Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany; 2Experimental and Clinical Research Center (ECRC), Charité Campus Buch, Humboldt-University, Berlin, Germany; 3Siemens Healthcare, Erlangen, Germany; 4Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany Abdominal imaging examinations constitute a growing fraction of clinical MRI exams. Since ultrahigh field magnetic resonance imaging becomes more widespread, a range of applications established in the clinical scenario at 1.5 T and 3.0 T is emerging at 7.0 T. An eight channel transceiver surface coil array together with a 2D fast gradient echo sequence delivered high details of abdominal sub-millimeter anatomic structures, such as the gallbladder wall and subtle liver vessels without the application of contrast agent, and enabled T2*-Mapping of the liver at 7.0 T.
Christopher Antony Wadsworth1, Shahid A. Khan1, Simon D. Taylor-Robinson1, Wladyslaw M W Gedroyc2, Munir M. Ahmad3, Richard R. A. Syms3, Ian R. Young3 1Department of Hepatology & Gastroenterology, Imperial College, London, United Kingdom; 2MRI Unit, Imperial College Healthcare NHS Trust, London, United Kingdom; 3Department of Electrical and Electronic Engineering, Imperial College, London, United Kingdom Problem: Strictures in the biliary tree are difficult to characterise as benign or malignant. A RF receiver microcoil applied directly to the biliary tree should improve MRI resolution substantially. Method: An innovative flexible catheter mounted microcoil has been developed. This was used as the receiver coil in MR imaging of a resected liver and biliary tree. Results: High resolution images were obtained. Signal to noise ratios and resolution were substantially better with the microcoil than with the standard coil. Conclusion: A prototype RF microcoil receiver can produce high quality images of ex vivo human liver tissue. These images demonstrate interpretable anatomical detail with sub-millimetre resolution and are superior to those obtained using a standard body coil. Ethan K. Brodsky1,2, Walter F. Block2,3, William Schelman4,5, Scott B. Reeder1,2 1Radiology, University of Wisconsin, Madison, WI, United States; 2Medical Physics, University of Wisconsin, Madison, WI, United States; 3Biomedical Engineering, University of Wisconsin, Madison, WI, United States; 4Carbone Cancer Center, University of Wisconsin, Madison, WI, United States; 5Medicine, University of Wisconsin, Madison, WI, United States Detection, characterization, and monitoring of hepatocellular carcinoma (HCC) is challenging due to its variable and rapid arterial enhancement. The ability to monitor changes in both morphology and perfusion is essential for evaluating the effectiveness of anti-angiogenic therapies. Multiple-phase CE-MRI has traditionally been used, but suffers from limited temporal resolution and an inability to consistently match acquisitions to the desired enhancement phase. We demonstrate the feasibility of contrast-enhanced isotropic-resolution 3DPR acquisition at 3T using a 32-channel coil with real-time monitoring that allows breath-holds to be matched to the desired enhancement phase and enables retrospective selection of the temporal window showing optimal lesion contrast. 2619. Contrast Uptake Enhancement Patterns in Neuroendocrine Liver Metastases Choon Hua Thng1, Tong San Koh2, Septian Hartono1, Puor Sherng Lee1, Keiko Miyazaki3, David Collins3, Martin O. Leach3, Val Lewington4, Dow-Mu Koh4 1National Cancer Centre Singapore, Singapore, Singapore; 2Nanyang Technological University, Singapore, Singapore; 3CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, United Kingdom; 4Royal Marsden NHS Foundation Trust, Sutton, United Kingdom Neuroendocrine liver metastases have been described as being hypervascular in nature, showing arterial enhancement and washout. However, other enhancement patterns have been observed in clinical practice (plateau and progressive enhancement). Three types of enhancement curves in neuroendocrine tumor was found: (1) Rapid increasing followed by decrease, (2) Rapid increasing followed by plateau, and (3) Progressively increasing. Type I pattern show higher intravascular volume (v1) compared to percentage of interstitial volume (v2). Type II and III pattern show higher v2 compared to v1. Type I pattern show higher blood flow (F) compared to Type II/III. Andrzej Roman Jedynak1, Frederick Kelcz1, Alex Frydrychowicz1, Scott K. Nagle1,2, Scott B. Reeder1,3 1Radiology, University of Wisconsin, Madison, WI, United States; 2Radiology, Middleton Veterans Affairs (VA) Hospital, Madison, WI, United States; 3Medical Physics, University of Wisconsin, Madison, WI, United States Primary sclerosing cholangitis (PSC) is a chronic inflammatory condition of extra- and intra-hepatic biliary ducts. In our clinical practice we routinely use the combination of high resolution gadoxetate-enhanced T1-MRC and heavily T2-weighted MRCP for the evaluation of PSC. This work set out to validate the clinical diagnostic utility of adding high-resolution 3D T1-weighted gadoxetate-enhanced hepatobiliary phase MRC to 3D T2 weighted MRCP. Preliminary results indicate that T1-MRC is an excellent adjunct to T2 MRCP that provides not only anatomical visualization of the biliary tree and associated disease but also offers useful functional/physiologic information that can be tremendously helpful in many cases. Hiroumi Kitajima1, Puneet Sharma, Christina Lurie, Khalil Salman, Gaye Ray, Bobby Kalb, Diego Martin 1Emory University, Atlanta, GA, United States Gd-EOB-DTPA demonstrates liver clearance kinetics that allow for its use as a marker for patients with chronic liver disease. Signal uptake, uptake rate, and common bile duct excretion as imaged by 3D T1-weighted GRE allow for quantitative assessment of liver fibrosis. Natalie Yang1, Sarah Jenkins1, Errol Colak1, Anish Kirpalani1 1Radiology, St Michael's Hospital, Toronto, Ontario, Canada The effect of butylscopolamine (Buscopan) on image quality for MR cholangiopancreatography (MRCP) examinations is examined in our study. The inferior common bile duct demonstrated improved visualization after the administration of butylscopolamine whilst other ductal segments demonstrated minimal benefit. The use of butylscopolamine in patients with suspected inferior common bile duct disease improves image quality and thus may improve diagnosis. feng zhang1, Huidong Gu1, Yanfeng Meng1, Bensheng Qiu1, Xiaoming Yang1 1Image-Guided Bio-Molecular Intervention Section, Department of Radiology, University of Washington School of Medicine, Seattle, WA, United States MR imaging was used to investigate the capability of Motexafin gadolinium(MGd) entering human cholangiocarcinoma cells (Mz-ChA-1) and the feasibility of intrabiliary local delivery of MGd into the common bile duct(CBD) wall. T1 weighted MR imaging of Mz-ChA-1 cells treated with MGd demonstrated a linear increase of signal intensities(SI) from 25 to 75-¦Ģg/mL MGd, and a plateau pattern of SIs from 75 to 150-¦Ģg/mL MGd. Confocal microscopy showed MGd internalized Mz-ChA-1 cells as intracytoplasm pink dots. Ex vivo experiments revealed significant higher contrast-to-noise ratio in the MGd-infused CBD walls than that in the controlled CBD walls with phosphate-buffered saline. 2624. 7T Liver MRI in Humans: Initial Results. Lale Umutlu1, Andreas K. Bitz2, Stefan Maderwald3, Stephan Orzada3, Sonja Kinner4, Oliver Kraff, Irina Brote, Susanne C. Ladd, Gerald Antoch, Mark E. Ladd3, Harald H. Quick3, Thomas C. Lauenstein 1Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen , Essen, Germany; 2Erwin L.Hahn Institute for Magnetic Resonance Imaging, Essen, Germany; 32Erwin L.Hahn Institute for Magnetic Resonance Imaging; 41Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen Aim of this study was to investigate the feasibility of 7 Tesla liver MRI, with optimization and implementation of a dedicated examination protocol. 8 healthy subjects were examined at a 7T whole-body MR system utilizing a custom-built 8-channel RF transmit/receive body coil. Delineation of liver vessels, overall image quality and presence of artifacts was assessed. T1w imaging revealed very good delineation of liver vasculature, with best imaging scores for T1w 2D FLASH imaging. T2w TSE imaging remained strongly impaired by artifacts. This pilot study of dedicated hepatic imaging at 7 Tesla demonstrates the feasibility of in vivo ultra-high-field liver imaging. Toshihiro Furuta1,2, Masayuki Yamaguchi1, Ryutaro Nakagami1,3, Akira Hirayama1,4, Masaaki Akahane2, Manabu Minami5, Kuni Ohtomo2, Hirofumi Fujii1 1Functional Imaging Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan; 2The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan; 3Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, Japan; 4GE Healthcare Japan, Hino, Tokyo, Japan; 5Tsukuba University Hospital, Tsukuba, Ibaraki, Japan Hepatic signal recovery on MR images after a single dose of superparamagnetic iron oxide (SPIO) would be well correlated with exocytic activity of Kupffer cells (KCs). In this study, we actually showed the delay of hepatic signal recovery after SPIO administration depending on the severity of KCs' injury in an animal model, in which rat KCs were injured by intravenous administration of gadolinium chloride in a dose-dependent manner. We believe that at least two-week follow up MR imaging scans after SPIO administration are useful for the evaluation of not only phagocytic but also exocytic activities of KCs. Zoran Stankovic1, Zoltan Csatari1, Peter Deibert2, Wulf Euringer1, Wolfgang Kreisel2, Susanne Eggerking2, Philipp Blanke1, Zahra Abdullah Zadeh1, Jürgen Hennig1, Mathias Langer1, Michael Markl1 1Department of Diagnostic Radiology and Medical Physics, University Hospital Freiburg, Freiburg, Baden Württemberg, Germany; 2Gastroenterology, University Hospital Freiburg, Freiburg, Baden Württemberg, Germany Time-resolved flow-sensitive 4D MRI permits qualitative and quantitative evaluation of portal venous hemodynamics of liver cirrhosis patients compared to volunteers. Our results demonstrate a persistent reduction of the peak velocities in the portal venous system between patients and different age group volunteers. Analysis showed significant correlation for peak and mean velocities between MRI and US measurements (r=0.53, p< 0.001) which served as reference standard. In liver cirrhosis patients 3D MR velocity mapping may be a standardized technique for evaluating flow characteristics modification, therapy monitoring or disease progression. Metabolism, Diabetes & Spectroscopy Hall B Tuesday 13:30-15:30 2627. Metabolic Profilings of Urine from High Fat-Fed Rats Based on 1H NMR Metabolomics Jingjing Xu1, Changqin Liu2, Shuhui Cai1, Jiyang Dong1, Zhong Chen1 1Department of Physics, Fujian Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, Fujian, China; 2The First Hospital of Xiamen Affiliated to the Xiamen University, China The biochemical variations of urine from chow- and high fat-fed rats were investigated using NMR-based metabolomics. Two groups can be discriminated clearly according to the scores plot of partial least squares discriminant analysis. The plot of variable importance in projection shows that taurine, succinate, hippurate, choline, citrate, dimethylamine, acetate, dimethylglycine, creatine, creatinine, tyrosine, glycine and lactate are contributed to the classification. In addition, the metabolic change with the development of obesity was also explored. 2628. Effects of a High-Fat Diet on Multiple Organ Systems in Mice: A MRI and MRS Study Sabrina Doblas1, Philippe Garteiser1, Joanna DeMoe1, Tim Griffin1, Luke Szweda1, Rheal Towner1 1Oklahoma Medical Research Foundation, Oklahoma City, OK, United States Magnetic resonance imaging is an in vivo imaging technique well adapted to measure and localize body fat contents and study obesity. Twenty-week old mice fed a high-fat or a normal diet were assessed on a 7 Tesla MRI system. Whole body, cardiac and knee joint images as well as cardiac 1H spectra were obtained and processed to assess the effects of a high-fat diet on adipose tissue distribution, joint damage and cardiac function. Fat mice had larger hearts, larger knee fat pads and fatter cardiac tissue than the lean animals. Kenneth Hollander1, Catherine Tempel-Brami2, Fred M. Konikoff1, Menahem Fainaru3, Alicia Leikin-Frenkel1 1Minerva Center for Lipid Metabolism in the Liver, Sackler School of Medicine, Tel Aviv University, Israel; 2Alfredo Federico Strauss Center for Computational Neuro-Imaging, Tel Aviv University, Tel Aviv, Israel; 3Department of Physiology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel The mammalian fetus is completely dependent on the fatty acids supplied by its mother inside the uterus. In the present study we analyzed the impact of fatty acids in pregnant mother's isocaloric diet on obesity and insulin resistance in adult offspring (DOAD). Body fat in pregnant mothers and offspring was measured by MRI and correlated with tissues fat and insulin resistance in adult offspring. Essential Fatty Acids prevented adult offspring obesity and insulin resistance whereas saturated fatty acids promoted it. MRI measured body fat correlated with HOMA index, tissues lipid content and SCD activity in white adipose tissue. 2630. AGAT-/- Mice: A Metabolic Puzzle of Energy Deficiency and Insulin Sensitivity Patricia Maria Nunes1, Christine I. H. C. Nabuurs1, Dirk Isbrandt2, Cees Tack3, Arend Heerschap1 1Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; 2Centre for Molecular Neurobiology, Institute for Signal Transduction, Hamburg, Germany; 3Department of General Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands Whole body creatine depletion causes several disarrangements in brain and muscle. In these conditions, AGAT-/-mice, a mouse model for deficient creatine biosynthesis, have enhanced food intake and permanent lower body weight which may reflect a higher substrate catabolism. We assessed ex vivo hepatic triglyceride concentration and the respective synthesis contributions from de novo lipogenesis (DNL) and dietary free fatty acids, by 1H / 2H-NMR. Additionally, we evaluated whole body glucose and insulin levels during a glucose tolerance test. Our results showed that AGAT-/- had lower hepatic triglycerides and the contribution from DNL, to this pool, was increased. On the contrary, dietary fatty acids contribute less to the hepatic triglyceride pool. This suggests that dietary fatty acids are preferentially recruited to high energy demanding tissues as muscle. These data matched with lower glucose and insulin concentrations during the glucose tolerance test, reflecting an insulin sensitive phenotype. Valeria Righi1,2, Yiorgos Apidianakis3, Dionyssios Mintzopoulos1,2, Loukas G. Astrakas, 1,4, Laurence G. Rahme3, A Aria Tzika1,2 1NMR Surgical Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States; 2Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, United States; 3Molecular Surgery Laboratory, Department of Surgery, Massachusetts General Hospital and Shriners Burns Institute, Harvard Medical School, Boston, MA, United States; 4Department of Medical Physics, University of Ioannina, Ioannina, Greece We demonstrate biomarker profiles with high-resolution magic angle spinning proton MR spectroscopy (HRMAS H1 MRS) of live Drosophila melanogaster flies. We show that the metabolic HRMAS MRS profiles of adipokinetic hormone receptor (akhrnull) mutant flies, which have an obesity phenotype, are different from isogenic control strain flies (akhrrev). Our approach advances the development of novel, in vivo, non-destructive research approaches in Drosophila, suggests biomarkers for investigation of biomedical paradigms, and thus may contribute to novel therapeutic development in obesity. Curtis L. Johnson1, Mina C. Mojtahedi2, Diego Hernando3,4, Dimitrios C. Karampinos1,4, Matthew P. Thorpe2, Danchin Chen1, Ellen M. Evans2,5, John G. Georgiadis1,4 1Mechanical Science and Engineering Department, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 2Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 3Electrical and Computer Engineering Department, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 4Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 5Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, IL, United States MRI was used before and after a weight loss intervention investigating the effect of diet on body composition in obese, older women to quantify changes in adiposity in the thigh. A two-point Dixon method was used to separate fat and water images in order to quantify subcutaneous, intermuscular, and intramuscular fat as well as muscle in the thigh before and after weight loss for two groups of subjects, one taking a protein supplement and the other taking a carbohydrate for control. Results showed greater loss of adipose tissue and retention of muscle for the protein group compared to the control. 2633. Magnetic Resonance Imaging of the Pancreatic Vasculature in Type 1 Diabetes Zdravka Medarova1, Zeynep Onder1, Marytheresa Ifediba1, Dale Greiner2, Guangping Dai1, Gerrardo Castillo3, Elijah Bolotin3, Anna Moore1 1Molecular Imaging Lab, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States; 2Department of Medicine, University of Massachusetts Medical School, Worcester, MA, United States; 3PharmaIN, Ltd, Seattle, WA, United States Vascular changes are commonly associated with many pathologies, including, cancer, arthritis, and diabetes. In type 1 diabetes, autoimmune lymphocytic infiltration progresses over many years, culminating in the destruction of a critical mass of insulin-producing beta-cells, and ultimately, in hyperglycemia and metabolic dysregulation. Vascular parameters, such as vascular volume, flow, and permeability are an important disease biomarker. It is important to monitor the dynamics of pancreatic microvasculature noninvasively. Here, we describe the application of the long-circulating, paramagnetic T1 contrast agent, PGC-GdDTPA-F for the noninvasive evaluation of vascular changes in a rat model of type 1 diabetes. Sandrine Duteil1,2, Sabrina Chiheb3, Claire Wary1,2, Emmanuel Cosson3, Aurélien Monnet1,2, Paul Elie Valensi3, Didier Mesengeau3, Pierre Georges Carlier1,4 1NMR Laboratory, Institute of Myology, F-75651 Paris, France; 2CEA, I²BM, MIRCen, IdM NMR Laboratory,, F-75651 Paris, France; 3Endocrinology, Jean Verdier Hospital, F- 93140 Bondy, France; 4CEA, I²BM, MIRCen, IdM NMR Laboratory, , F-75651 Paris, France Microangiopathic complications are a major concern in diabetes mellitus type II. Oxidative phosphorylation may also be impaired, with a yet imprecise relationship to microangiopathy . An integrative investigation of metabolic and vascular response to stress was carried out to determine possible alterations of perfusion and oxidative metabolism in calf muscle of 96 patients, categorized according to incidence of microangiopathy. Combining perfusion, oxygenation and energetic measurements, we could show that mitochondrial activity was altered in patients with poorly controlled glycaemia, but unrelated to reduced perfusion, which was common to all patients, while possible anomalies of oxygen diffusion might reflect diabetic microangiopathy.
Riikka J. Immonen1, Smaragda Lamprianou2, Laurent Vinet2, Paolo Meda2, Rolf Gruetter1,3 1Laboratory for functional and metabolic imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland; 2Department of Cell Physiology and Metabolism, University of Geneva, Geneva, CH-1210, Switzerland; 3Department of Radiology, University of Geneva and Lausanne, Geneva and Lausanne, CH-1210 and CH-1015, Switzerland In diabetes the gradual loss of pancreatic βcells leads to impaired regulation of blood glucose levels. βcell islets, 30-600μm in diameter, are sparsely located accross the pancreas. We utilized for the first time ultra high field of 14.1T in combination of manganese- and iron-oxide nanoparticle-enhanced MRI to assess pancreatic structures ex vivo. We were able to distinguish all the main pancreatic structures, including lobules and branching duct tree with terminal acini. The manganese with glucose stimulus, without and together with the infusion of iron oxide particles, also delineated structures which are likely to correspond to individual pancreatic islets. 2636. Could Obesity Possibly Be Harmless Lidia S. Szczepaniak1, Jaime L. Legendre2, Edward W. Szczepaniak1, Angela L. Price2, Ildiko Lingvay2 1The Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States; 2Endocrinology, UT Southwestern Medical Center, Dallas, TX, United States There is no doubt that obesity is associated with diabetes, increased cardiovascular risk factors, not to mention arthritis and cancers. Sixty to 90% of patients with diabetes are obese but not all obese individuals present metabolic and cardiovascular diseases. This leads to a notion that certain individuals tolerate obesity well and without metabolic consequences. We present clinical evidence that given enough time the so called "healthy obesity" eventually becomes harmful with full spectrum of metabolic consequences. 2637. Beneficial Effects of Diethylnorspermine in Obesity and Its Cardiac Complications MingMing Li1, Beau Pontre2, Stephen Pickup3, Hong Xu4, Anthony Philips2, Garth Cooper2, Jun Lu2,5 1School of Biological Sciences, Auckland University, Auckland, New Zealand; 2School of Biological Sciences, Auckland University, New Zealand; 3Department of Radiology, University of Pennsylvania, Philadelphia, United States; 4College of Chemistry and Chemical Engineering, Shen Zhen University, Shenzhen, Guangdong, China; 5NCIECP, Auckland University of Technology, Auckland, New Zealand We hypothesise that chemically induced Spermidine/spermine acetyl transferase (SSAT) activity, which stimulates polyamine catabolism and in turn enhances fat/glucose metabolism, would decrease fat content and improve cardiac function in obese mice. C57Bl/6 and matched leptin deficiency (ob/ob) mice were treated with a potent SSAT inducer, N1, N11-diethylnorspermine (DENS), through i.p. injection. Results showed that DNES not only can significantly reduce body fat percentages in both mice models, but also can control ob/obs body weight. Moreover, DENS can prevent the development of cardiac hypertrophy in obese mice. Therefore, SSAT is a potential target for the development of pharmacotherapy in obesity. 2638. Patient Specific T2 correction in Hepatic Fat Content Measurement in Obese Patients Annie M. Tang1, Kelvin K. Wong1, Kathleen Wyne2,3, Dikoma C. Shungu4, Willa Hsueh2,5, Stephen T. Wong1 1Center for Bioengineering and Informatics and Department of Radiology, The Methodist Hospital Research Institute, Weill Cornell Medical College, Houston, TX, United States; 2Diabetes Research Center, The Methodist Hospital Research Institute, Houston, TX, United States; 3Division of Diabetes, Obesity & Lipids, The Methodist Hospital, Weill Cornell Medical College, Houston, TX, United States; 4Department of Radiology, Weill Cornell Medical College, Cornell University, New York, NY, United States; 5Division of Diabetes, Obesity & Lipids , The Methodist Hospital, Weill Cornell Medical College, Houston, TX, United States 1H-MRS is used for quantifying liver fat content in patients with NAFLD. T2 corrections of hepatic fat/water are usually done using T2 values obtained in literature. However, these T2 values of depends a lot on the concentration of iron in the liver. In patients with NAFLD, different degree of iron concentration was observed depending on the patient sex and diabetes status. We are conducting an ongoing pilot trial to study the hepatic fat content in obese patients before and during diet/weight management. The hepatic water and fat T2 relaxation values were measured and its effects in hepatic fat content measurements were explored. 2639. Triglyceride Composition Measured by 1H MRS at Clinical Field Strengths Gavin Hamilton1, Michael S. Middleton1, Takeshi Yokoo1, Mark Bydder1, Michael E. Schroeder1, Claude B. Sirlin1 1Department of Radiology, University of California, San Diego, San Diego, CA, United States The multi-peak structure of the fat 1H MR spectrum allows the triglyceride composition in adipose tissue to be estimated non-invasively. We assess the ability of 1H MR spectroscopy to reproducibly provide information about triglyceride composition in adipose tissue in vivo at clinical field strengths. 2640. In Vivo Repeatability of Liver Fat Measurement Using 1H MR Spectroscopy Gavin Hamilton1, Michael S. Middleton1, Takeshi Yokoo1, Masoud Shiehmorteza1, Claude B. Sirlin1 1Department of Radiology, University of California, San Diego, San Diego, CA, United States We examined the repeatability of the liver fat fraction given by MR Spectroscopy. We measured the fat fraction at 3T in vivo by collecting five single average STEAM spectra at progressively longer of TEs of 10, 15, 20, 25 and 30 ms in a single breath-hold to generate T2 and T2-corrected peak areas. We repeated this measurement three times per subject and showed this method produced highly repeatable liver fat fraction and water T2 estimates. This method did not produce a repeatable estimate of fat T2. 2641. On the Evaluation of 31P MRS Human Liver Protocols. Mikael F. Forsgren1, Olof Dahlqvist Leinhard2,3, Bengt Norén4, Stergios Kechagias, Fredrik H. Nyström, Örjan Smedby2,3, Peter Lundberg, 3,4 1Linköping University; 2Faculty of Health Sciences/IMH, Linköping University, Linköping, Sweden; 3Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden; 4Radiology, Linköping University Hospital In this study the effect of proton decoupling, nuclear overhauser enhancement and repetition time was investigated in 31P liver MRS at 1.5T. An optimal protocol was determined and validate on 13 healthy volunteers. Jing Qi1, Amita Shukla-Dave1, Jason Koutcher1, Mithat Gönen2, Yuman Fong3, Lawrence H. Schwartz4, Kristen L. Zakian5 1Medical Physics, Memorial Sloan-Kettering Cancer Center; 2Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center; 3Surgery, Memorial Sloan-Kettering Cancer Center; 4Radiology, Sloan-Kettering Cancer Center; 5Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY, United States In order to evaluate reproducibility of liver metabolites measured by 1H decoupled-31P MRSI technique, 13 normal subjects were investigated twice at 2 weeks interval. Concentration of PE, PC, PME, Pi, GPE, GPC, PDE and NTP were calculated. Inter- and intra- subject variations were analyzed. Inter- and intra-subject coefficient variation ranged from 11% to 25 % for all metabolite concentration. Intra-subject reproducibility was not superior to inter-subject reproducibility, indicating that the random biological differences dont seem to exceed the differences generated by technical variation in normal volunteers. Both technical and biological factors should be considered when interpret liver 31P MRSI data. Michael Germuska1, Jian Xu2, Martin Leach1, Geoffrey Payne1 1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, London, United Kingdom; 2Siemens Healthcare U.S., New York, NY, United States In vivo 1H MR spectroscopy has proved valuable for evaluating tumours. However, acquisition of spectra in the abdomen is complicated by respiratory motion. The motion degrades the spectral quality by phase and frequency distortions and by modification of the PSF. We compared two approaches to combat motion in liver spectroscopy. The first utilises a post-processing approach to correct phase and frequency distortions, the second employs prospective gating when acquiring the data. Both techniques showed an improvement in linewidth and SNR compared to free-breathing acquisitions. The post-processing methodology showed an advantage in SNR due to the increased number of signal averages. 2644. Ω-3 Fatty Acid Detection by L-COSY in Human Bone Marrow at 3T Saadallah Ramadan1, Robert V. Mulkern2, Carolyn E. Mountford1 1Radiology, Brigham and Women's Hospital, Boston, MA, United States; 2Radiology, Childrens Hospital, Boston, MA, United States 3 is an essential fatty acid (FA) that cannot be synthesized in the body and is obtained by diet. In the human body, essential FA serve multiple functions including neuroprotective functions, mood, behavior and prevents inflammation. There are two types of £s-3 FAs: eicosapentaenoic acid (EPA) docosahexaenoic acid (DHA), both of these molecular structures end with R-HC=CH-CH2-CH3. We investigated possibility of detecting ē-3 in human bone marrow, at 3T, using localised one dimensional (1D) (PRESS) and localized two-dimensional (2D) correlation spectroscopy (L-COSY). Body Diffusion Hall B Wednesday 13:30-15:30 2645. Effect of Region of Interest Position on Liver Apparent Diffusion Coefficient. Daniel Wilson1, J. Ashley Guthrie2, Janice Ward2 1Medical Physics, Leeds Teaching Hospitals NHS Trust, Leeds, West Yorkshire, United Kingdom; 2Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, West Yorkshire, United Kingdom The liver ADC was measured in 3 different positions in the liver in 33 subjects. The mean ADC was signficantly different between the 3 different positions. This is attributed to the presence of noise in the middle of the liver and artefactual signal loss at high b-values at superior positions in the left lobe. Care must be taken when measuring ADC in the liver. 2646. Continuously Moving Table Whole-Body MRI Using Variable Field of View Robert L. Janiczek1,2, Jonathan W. Howard2, Giulio Gambarota2, John S. Thornton1, Xavier Golay1, Rexford D. Newbould2 1Institute of Neurology, University College London, London, United Kingdom; 2GSK Clinical Imaging Centre, London, United Kingdom Continuously moving table (CMT) acquisitions have been proposed whereby data are collected in a hybrid space as the patient moves through the scanner. In CMT acquisitions the table velocity and therefore scan duration is proportional to the in-plane FOV. This work investigates the use of varying the FOV as a function of patient position in order to reduce scan time. A low-resolution scout scan is used to design a k-space sampling pattern that matches the minimal FOV requirement. The use of a variable FOV CMT acquisition is shown to reduce scan time by 32% over a conventional constant FOV design. 2647. Diffusion-Weighted Imaging of the Abdomen with Readout-Segmented (RS)-EPI Samantha J. Holdsworth1, Stefan Skare1, Shreyas S. Vasanawala1, Roland Bammer1 1Radiology, Stanford University, Palo Alto, CA, United States Diffusion-weighted imaging (DWI) in the abdomen has proven useful for the various pathologies including liver lesion characterization and diagnosis of diffuse renal disease. However, image distortions arising from the use of EPI has shown to be problematic. In this work we explore the use of readout-segmented (RS)-EPI for DWI of the abdomen and show that it may be a useful method for reducing geometric distortion and blurring. Yeji Han1, Sandra Huff1, Juergen Hennig1, Ute Ludwig1 1Medical Physics, Dept. of Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany Superior disease contrast and no need for extra administration of exogenous contrast medium contribute to the advantages of diffusion-weighted imaging (DWI) over other modalities for patient screening and treatment monitoring. However, the clinical impact of whole-body DWI (wbDWI) remains limited due to the technical difficulties of multistation approach. In this study, we have developed a continuously moving table (CMT) wbDWI method based on a STIR-EPI sequence as an alternative to currently used multistation wbDWI sequence. The preliminary results successfully demonstrate that CMT wbDWI can be a promising technique to overcome the problems of multistation wbDWI approach. 2649. Characterization of Multicompartmental Renal Diffusion Using a Stretched Exponential Model Claudia Lenz1, Gregor Sommer2, Klaus Scheffler1, Leopold Winter2, Markus Klarhöfer1 1Radiological Physics, University of Basel Hospital, Basel, Switzerland; 2Department of Radiology, University of Basel Hospital, Basel, Switzerland In biologic tissues, microscopic motion of water not only includes molecular diffusion, but also microcirculation of blood in the capillary network. The intraxovel incoherent motion model has been introduced to describe these combined diffusion and microcirculation effects in diffusion weighted imaging. Analysis of the multicompartmental water diffusion is mostly performed by applying a biexponential fit function to the diffusion curve and evaluating the diffusion and perfusion components separately. However, this technique often suffers from high standard fit errors, especially for the perfusion fraction f. In 2003, Bennett et al. proposed a stretched exponential model to account for the multiexponential behavior of diffusion curves in the brain. In this work, we extended the stretched exponential model to the abdomen and present fit results from the kidneys of healthy subjects. Thomas Gaass1, Bram Stieltjes, Frederik Laun1 1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany The aim of this work was to evaluate whether diffusion weighted imaging (DWI) and inversion recovery (IR) may be applied without interference. DWI of the liver shows that the apparent diffusion coefficient (ADC) measured in a single voxel is clearly dependent on the inversion time and ADCs vary between -0.007 s/mm² and 0.009 s/mm² in a 100 ms TI interval. The counterintuitive negative diffusion is observed in the liver and in regions with incomplete fat saturation. This can be explained by the here proposed two compartment model. Thus, DWI and IR can generally not be applied without interference. 2651. Diffusion-Weighted Imaging of the Kidney: Beyond Mono- And Bi-Exponential Models Anna Caroli1, Luca Antiga1, Giuseppe Petralia2, Massimo Bellomi2, Andrea Remuzzi1,3, Paul Summers2 1Bioengineering Department, Mario Negri Institute for Pharmacological Research, Bergamo, Italy; 2Division of Radiology, European Institute of Oncology, Milan, Italy; 3University of Bergamo, Bergamo, Italy Mono-exponential models do not accurately predict diffusion-weighted signal decay in the kidney, while bi-exponential models are unable to differentiate contributions. We propose a piece-wise exponential model, separately fitting low and high b-values with two exponentials, expressive of fast and slow transport components. Ten healthy volunteers underwent DWI both pre- and post-lunch, and acquisitions were repeated within one of the two sessions. The model was stable, and accurately fit signal attenuation. Diffusion parameters showed high repeatability, but significant differences between pre- and post-meal acquisitions. These results point out the need for more complete interpretations of DWI signal in describing the complex transport in the kidney. Susan Moyher Noworolski1,2, Phyllis Tien3,4, Michelle Nystrom1, Suchandrima Banerjee5, Aliya Qayyum1 1Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States; 2The Graduate Group in Bioengineering, University of California, San Francisco and Berkeley, CA, United States; 3Medicine, University of California, San Francisco, CA, United States; 4Medicine, Veteran Affairs Medical Center, San Francisco, CA, United States; 5MR Applied Science Lab, GE Healthcare, Menlo Park, CA, United States The impact of a perfusion regime, low b-value ADC, and a tissue regime, high b-value ADC were evaluated in comparison to a conventional ADC in three groups of subjects: HIV/HCV (hepatitis C) coinfection, HIV-monoinfection, and without infection. Liver ADC was measured using b values of 0 and 150 (ADClow), 150 and 600 (ADChigh) and 0 and 600 (ADCconv) in one breathhold sequence. ADClow and ADChigh provided unique information. HIV tended to have the highest ADC levels and was significantly higher than HIV/HCV for ADClow and ADCconv. HIV status may thus be an important consideration in interpretation of liver ADC. 2653. SSFP Diffusion Prepared SSFSE Weiying Dai1, Philip M. Robson1, David C. Alsop1 1Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States SSFP diffusion weighted imaging in the body can have improved image quality relative to echoplanar imaging. Its stronger diffusion attenuation of longer T2 fluid may also be a particular benefit in cancer screening studies, but the slow acquisition speed is a major limitation. Here we propose performing a diffusion weighted SSFP sequence as a preparation for a faster SSFSE sequence. The theoretical signal is described and pulse parameters are optimized. The resulting sequence is then applied to in-vivo diffusion weighted imaging of volunteers. Excellent suppression of fluid and blood signal is demonstrated. Beena George1, Andriy Babsky1, Navin Bansal1 1Radiology, Indiana University, Indianapolis, IN, United States Diffusion weighted (DW) 1H MRI may be useful in the diagnosis of liver diseases. Fast and slow apparent diffusion coefficients (ADCfast and ADCslow, respectively) were separated in the normal rat liver by using ten b values. After mortal ischemia, ADCfast disappeared, demonstrating that this component results from microcapillary blood perfusion. ADCslow decreased after ischemia, most likely due to intracellular accumulation of water. DW 1H MRI can provide information about tissue perfusion and molecular diffusion which are both important physiological parameters. Yousef Mazaheri1, Daniel B. Rowe2, Jingbo Zhang3, Hedvig Hricak3, Jason A. Koutcher1 1Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States; 2Mathematics, Statistics, and Computer Science, Marquette University, Milwaukee, WI, United States; 3Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States A stretched exponential model is presented to describe intravoxel incoherent motion (IVIM) signal. Simulations results show that the distributed diffusion coefficient and į is a dimensionless stretching parameter have tolerable CV (<15% at 5% noise) and bias (absolute bias< 11% at 5% noise). In vivo renal data suggests that the stretched exponential model has potential to describe the pseudo-diffusion behavior at low b-values. 2656. Relaxation Time Effects in Intra Voxel Incoherent Motion Imaging Andreas Lemke1, Frederik Bernd Laun2, Dirk Simon3, Bram Stieltjes4, Lothar Rudi Schad1 1Department of Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 3Software Development for Integrated Diagnostics and Therapy, German Cancer Research Center, Heidelberg; 4Department of Radiology, German Cancer Research Center, Heidelberg, Germany The DWI signal was measured as a function of the b-value in the pancreas using three different echo times (TE=50, 70, 100 ms) from six healthy volunteers. A modified equation incorporating relaxation effects was introduced and parameters derived from this equation were compared to the original IVIM equation. The perfusion fraction f increased significantly with increasing echo time (P=0.0025) whereas the relaxation time compensated perfusion fraction f' showed no significant dependence on TE (P=0.31). The relaxation time compensation had no influence on the diffusion coefficients. Doenja Lambregts1, Monique Maas1, Vincent Cappendijk1, Jan Verwoerd2, Iris Rutten1, Geerard Beets3, Regina Beets-Tan1 1Radiology, Maastricht University Medical Center, Maastricht, Limburg, Netherlands; 2Philips Healthcare, Eindhoven, Netherlands; 3Surgery, Maastricht University Medical Center, Maastricht, Limburg, Netherlands Whole-body diffusion weighted imaging (WB-DWI) could prove to be a promising and feasible alternative to CT and PET-CT for distant metastases screening in colorectal cancer. This study aims to test the feasibility of WB-DWI for metastases screening and to compare the lesion detectability of WB-DWI to conventional staging techniques (CT and PET-CT) 2658. Liver Diffusion/perfusion Using Biexponential Analysis with 30 B-Values James Lee1, Masoud Shiehmorteza1, Michael E. Schroeder1, Katie H. Hansen1, Mark Bydder1, Claude Sirlin1 1Radiology, University of California San Diego, San Diego, CA, United States Diffusion imaging of the liver is reported as having slow and fast components ("perfusion"). We modeled both components before and after a meal to observe the effect of increasing perfusion. Bowel/Fetal & Female Pelvis/Renal & Male Pelvis Hall B Thursday 13:30-15:30 Mahamoud Omar Hussein1, Luca Marciani2, Mary Stephenson1, Caroline L. Hoad1, Eleanor F. Cox1, Elisa Placidi1, Susan Pritchard1, Henelyta Ribeiro3, Elisabetta Ciampi3, Pip Rayment3, Asish Nandi3, Nick Hedges3, Paul Sanderson3, Irmela Kruse3, Robin C. Spiller2, Penny A. Gowland1 1The Sir Peter Mansfied Magnetic Resonance Centre, School of Physics & Astronomy, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom; 2Nottingham Digestive Diseases Centre NIHR Biomedical Research Unit, The University of Nottingham, Nottingham, United Kingdom; 3Unilever Discover, Colworth Science Park, Bedford, United Kingdom MRI can monitor gastrointestinal function and visualise the water and fat components of food in the gut separately. This study describes development work aimed to combine MRI and MRS to provide a method of monitoring the gastrointestinal fate and absorption of fat in the skeletal muscle and liver. Two healthy volunteers were fed two fat emulsions of different droplet sizes and were scanned at intervals postprandially. The 2 different meals triggered a diverse duodenal response affecting gastric emptying, gallbladder contraction and small bowel secretion. MRS showed promise for monitoring changes in both liver and calf lipid/water ratios. 2660. Validation of Automated Motion Assesment in the Abdomen Andre M. Sprengers1, Aart J. Nederveen2, Rolf M. Lamerichs3, Jaap Stoker2 1Radiology, AMC , Amsterdam, Netherlands; 2Radiology, AMC, Amsterdam, Netherlands; 3Research, Philips, Eindhoven, Netherlands The assessment of small bowel motility is a difficult task because of its complex nature. SPAMM or SPatial Modulation of the Magnetization is a strong candidate for a minimally invasive, observer independent method of motion assessment. The SPAMM method uses a prepulse to impose a lineshaped pattern on the magnetization. Upon readout, this pattern is distorted as a result of tissue motion between prepulse and readout. Originally developed for cardiac imaging, the SPAMM sequence was reconfigured for nonperiodic motion. The novel SPAMM technique was validated by focussing on the heartmotion, breathing motion and small bowel motility. 2661. Ultrafast Abdominal MR Imaging in Children and Young Adults with Multitransmit MR Alisa Johnson1, Janusz Kikut1, Trevor Andrews2, Christopher G. Filippi3 1Radiology, Fletcher Allen Health Care-UVM, Burlington, VT, United States; 2MR, Philips Healthcare, Cleveland, OH, United States; 3Radiology, University of Vermont School of Medicine-Fletcher Allen Health Care, Burlington, VT, United States The purpose of this study was to compare ultrafast imaging of the abdomen using multitransmit MR with routine, fast MR imaging in children and young adults who presented with acute abdominal pain to the emergency room. 10 patients were studied. 5 were normal, and in the other 5 patients, correct diagnoses were made. Multitransmit MR imaging quality was rated the same or better in all cases. Improvements were noted in contrast, uniformity of fluid and fat signal, and less dielectric shading. Scan times were reduced, on average, by 48%. No sedation and no oral or intravenous contrast were needed. 2662. In Vivo Trans-Pyloric Mass Movement Dynamics Measured by Means of Phase-Contrast MRI Tobias Hahn1, Jelena Curcic1, Martin Buehrer1, Oliver Goetze2, Werner Schwizer2, Michael Fried2, Andreas Steingoetter, 1,3, Sebastian Kozerke1, Peter Boesiger1 1Institute for Biomedical Engineering, ETH and University Zurich, Zurich, Switzerland; 2Division of Gastroenterology and Hepatology, University Hospital of Zurich, Zurich, Switzerland; 3Institute of Radiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany This study aimed for assessing the feasibility of in vivo trans-pyloric flow measurements by means of phase-contrast MRI. Dynamic EPI sequences were studied in vitro and applied in vivo behind the pylorus. The gained velocity, frequency and backflow percentage show very good agreement with literature values and give rise for expecting great potential in fast EPI phase-contrast MRI for dynamic quantification of trans-pyloric mass movements. 2663. The Impact of Abdominal Mri of Pregnant Women on Clinical and Obstetrical Management Michal Marianne Amitai1, Miriam stern2, Marjory Hertz3, Yacov Itzchak3, yael Inbar3, Sara Apter3 1Diagnostic Imaging, Sheba Medical Center, Ramat Gan, Israel, Israel; 2Diagnostic Imaging, Sheba Medical Center,, Ramat Gan, Israel,, Israel; 3Diagnostic Imaging, Sheba Medical Center, Ramat Gan, Israel, Israel Purpose: To evaluate the impact of MRI of the abdomen and pelvis in pregnant women on clinical and obstetrical management. Methods: Thirty one consecutive MRI studies of the abdomen of 29 pregnant patients, were included in the study Correlation between the MRI pathological findings related to the stage of pregnancy and the clinical and obstetric outcome were evaluated. Results: The indications for studies included: gynecologic conditions (9), suspected Crohn disease (7), suspected appendicitis (6), cancer staging and follow up (5), postoperative complications (3) and suspected pheochromocytoma (1). Conclusions: MR imaging proved to be appropriate in the management of pregnant patients with diverse abdominal pathology and could provide an accurate diagnosis prior to delivery in all patients. 2664. The Effect of Maternal Smoking on Fetal Lung and Kidney Growth Devasuda Anblagan1, Carolyn Costigan2, Tomas Paus2, Zdenka Pausova2, Nia Wyn Jones3, George Bugg3, Nick Raine Fenning4, Penny Anne Gowland1 1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Brain and Body Centre, University of Nottingham, United Kingdom; 3Queen's Medical Centre, University of Nottingham, United Kingdom; 4Division of Human Development, School of Clinical Sciences, University of Nottingham, United Kingdom This study aims to identify the effect of maternal smoking during pregnancy on fetal lung and kidney growth. Pregnant women were scanned at 24th to 26th weeks and 34 to 36 weeks postconception. The lung and kidney MR images were analysed using semi automatic approach with Analyze software. Fetal lung and kidney volumes were reduced in the smoker group. 2665. Reliability Test for Fetal Fat Programme Devasuda Anblagan1, Carolyn Costigan2, Alain Pitiot3, Tomas Paus2, Zdenka Pausova2, Nia Wyn Jones4, George Bugg4, Ruta Deshpande4, Mona S. Moghazy A. Salmam4, Penny Anne Gowland1 1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Brain and Body Centre, University of Nottingham, United Kingdom; 3School of Psychology, University of Nottingham, United Kingdom; 4Queen's Medical Centre, University of Nottingham, United Kingdom This study aims to investigate the reliability of a MATLAB program designed to calculate the subcutaneous fat volume in the fetus. It will be employed in a study investigating macrosomia outcomes in diabetic pregnant mothers. The MR technique used to assess the foetal growth is Fat Sequences with Water Suppression where pregnant women were scanned in late pregnancy (after 30th gestation week) when fetal fat is more visible. Sylvie Girard1, Luc Tremblay2, Guillaume Sebire1, Martin Lepage2 1Pediatric, Universite de Sherbrooke, Sherbrooke, Qc, Canada; 2Radiobiology, Universite de Sherbrooke, Sherbrooke, Qc, Canada Perinatal inflammation predominantly affects preterm newborns leading to brain damage. Interleukin-1 (pro-inflammatory molecule) appears to be a key mediator linking maternal inflammation and fetal brain damage. Strategies to protect the fetal brain are currently unavailable mainly due to the lack of non-invasive tools to detect in utero inflammation and monitor the impact of an anti-inflammatory treatment. We showed that MRI is a potent technique to detect placental damage and can be used to monitor the impact of anti-inflammatory treatment in an animal model of prenatal inflammation. 2667. Assessment of Placental Morphology and Magnetic Resonance Imaging Biomarkers at 1.5 Tesla David M. Morris1,2, Caroline Wright3, Philip N. Baker4, Ian P. Crocker3, Penny A. Gowland5, Geoff J. Parker1,2, Colin P. Sibley3 1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University of Manchester, Manchester, United Kingdom; 2The University of Manchester Biomedical Imaging Insitute, University of Manchester, Manchester, United Kingdom; 3Maternal & Fetal Health Research Centre, University of Manchester, Manchester, United Kingdom; 4Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Canada; 5Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, United Kingdom Fetal growth retardation (FGR) is a serious condition affecting babies in utero that can be identified by means of a placental phenotype related to structural and functional changes in the placenta. Magnetic resonance imaging (MRI) measured the relaxation times T1 and T2 as possible biomarkers of this condition and placentas were collected for the histological verification of FGR pathology. We show for the first time that both in utero T1 and T2 demonstrate a significant negative correlation with the gestational age at 1.5 T and that relaxation times correlate with histological biomarkers of placental development. 2668. T1-Weighted Imaging of Fetal Microcolon Erika Rubesova1, James Gilmore1, Shreyas Vasanawala1, Richard A. Barth1 1Pediatric Radiology, Lucile Packard Children's Hospital at Stanford, Stanford, CA, United States T1-weighted images allow visualisation of the fetal colon. Microcolon is important to recognize since it aids to accurate diagnosis in patients referred for fetal MRI with gastrointestinal abnormalities. In our retrospective study, we reviewed the T1-weighted images in fetuses with microcolon and tried to define the optimal plane andsequence (FGRE versus 3D dual-echo SPGR) for evaluation of the microcolon. Ian J. Tagge1, Cecily V. Bishop2, Richard L. Stouffer2,3, Charles S. Springer, Jr. 1, Xin Li1 1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States; 2Division of Reproductive Sciences, ONPRC, Oregon Health & Science University; 3Department of Obstetrics and Gynecology, Oregon Health & Science University The female uterus and ovary are among the few normal tissues to undergo periodic angiogenic changes. Using a primate model (rhesus macaque), we investigate the feasibility of DCE-MRI to quantify blood volume fraction (vb) and contrast reagent (CR) transendothelial permeability. The standard model with vb (SM2) and the second generation shutter-speed model (SSM2), are used in parallel for this effort. Martin D. Pickles1, Sue Booth2, Lindsay W. Turnbull1 1Centre for MR Investigations, University of Hull, Hull, East Yorkshire, United Kingdom; 2Institue of Oncology, St James' Hospital, Leeds, West Yorkshire, United Kingdom Chemoradiotherapy in combination with brachytherapy has become the standard treatment for advanced cervical carcinomas. Although the intent of the treatment is curative a significant number of patients do not survive beyond 5 years. Consequently, biomarkers of reduced survival intervals are currently being sought. The aim of this work was to determine if any of the studied MR derived parameters were associated with longer disease free and/or overall survival. This study demonstrated that for this cohort the MR derived stage (FIGO or TNM) based on morphological assessment of the disease present provided the most significant association with survival intervals. 2671. Pelvic B1 Mapping at 3T for DCE Rexford D. Newbould1, Brandon Whitcher1 1GSK Clinical Imaging Centre, London, United Kingdom Dynamic contrast enhanced perfusion measurement (DCE) is hampered in the body at higher field strengths such as 3T by the large spread of achieved flipangles across the volume of interest. In DCE, it is common to measure the change in voxel T1 using a variable flipangle spoiled gradient echo sequence, in order to quantify contrast agent concentration. The extreme variation in achieved flip angle at 3T in the body has precluded accurate quantification. Here, B1 mapping using the saturated double angle method is performed rapidly in the same locations as the dynamic scan, in order to correctly estimate T1 values. Milou Patricia Helene Busard1, Velja Mijatovic2, Cees van Kuijk, Indra Pieters-van den Bos, Peter Hompes, Jan Hein van Waesberghe 1Radiology, VUMC, Amsterdam, Noord Holland, Netherlands; 2Gynecology, VUMC, Amsterdam, Noord Holland, Netherlands To assess the value of magnetic resonance (MR) diffusion-weighted imaging (DWI) in deep infiltrating endometriosis (DIE), DWI was added to the standard MR imaging protocol. Apparent diffusion coefficient (ADC) values were calculated using b-values of 50, 400, 800 and 1200 s/mm2. In 60 lesions, mean ADC values of DIE retrocervical (0.70 x 10-3/mm2 /s), infiltrating the colon (0.79 x 10-3/mm2/s) and bladder (0.76 x 10-3/mm2/s) were consistently low and did not significant differ between pelvic locations (p=0.63). In addition, ADC values show comparable diagnostic performance in differentiating endometrial cysts from other pelvic cysts as evaluation of T2- and T1-weighted images. David Joseph Niles1, Andrew L. Wentland1,2, Nathan S. Artz1, Thomas M. Grist1,2, Sean B. Fain1,2, Aji Djamali3, Elizabeth A. Sadowski2 1Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States; 2Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States; 3Nephrology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States Functional MR imaging techniques provide a non-invasive method for studying renal physiology. This study measured blood flow in the main renal artery using phase contrast MR, cortical and medullary perfusion using ASL and oxygenation using BOLD MR imaging sequences, in normotensive and hypotensive swine. Our results demonstrate medullary oxygenation is maintained despite a decrease in renal artery blood flow and regional tissue perfusion in the hypotensive states. This has been previously demonstrated by others with invasive probes in animals. Our functional renal MR techniques may be applied to future studies in humans to study blood flow and oxygenation simultaneously. Xuedong Yang1, Ju Cao2, Xiaoying Wang1 1Department of Radiology, Peking University First Hospital, Beijing, China; 2Nephrology Department, Peking University First Hospital, Beijing, China DW and BOLD MRI can reflect changes of water diffusion and oxygen level in TIN kidney. Both methods can be used to study the TIN patients. Combined use of the two methods may aid in differentiating ATIN, CTIN from normal kidney. Medullary R2* significantly correlates with eGFR in TIN patients. 2675. Measurements of Renal Perfusion, Oxygenation, and Total Renal Blood Flow in Swine Andrew L. Wentland1,2, Nathan S. Artz1, Arjang Djamali3, Thomas M. Grist1,2, Sean B. Fain1, Elizabeth A. Sadowski2 1Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States; 2Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States; 3Nephrology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States Given the recent link between nephrogenic systemic fibrosis and gadolinium-based contrast agents (GBCAs), it has become increasingly important to evaluate techniques that operate independently of GBCAs. In this study, measurements of perfusion, oxygenation, and total renal blood flow (TRBF) were acquired in swine with arterial spin labeling-based perfusion, BOLD MRI, and phase contrast MRI, respectively. Scans were repeated during a state of increased blood flow with acetylcholine and also a state of decreased blood flow with the anesthetic isoflurane over a two-hour period. Measurements successfully demonstrated increased perfusion, oxygenation, and TRBF with acetylcholine, and the opposite trend with isoflurane. 2676. Renal-ASL Using a Multiple-Inversion Time, Free Breathing, STAR-HASTE Technique at 3T Mark Stephen Dobbs1,2, Neil Woodhouse3, Geoff J.M Parker1,2, Josephine H. Naish1,2 1Imaging Science and Biomedical Engineering, The University of Manchester, Manchester, Greater Manchester, United Kingdom; 2The University of Manchester Biomedical Imaging Institute, Manchester, Greater Manchester, United Kingdom; 3AstraZeneca, Manchester, Greater Manchester, United Kingdom ASL has been applied extensively in the brain, but there has been increasing interest in applying ASL to the kidneys, particularly as a result of concerns over the link between contrast agents and NSF. Currently, most human renal-ASL has been performed using a single inversion time, and applying a simple model for quantification. In this abstract we aim to demonstrate the feasibility of applying the Buxton model, at 3T, using a STAR based labelling technique and a free breathing approach. Here, we demonstrate the practicality of fitting for arrival time, producing high quality parametric output. 2677. Non-Invasive Investigation of Diabetic Kidney Disease by Magnetic Resonance Imaging Peter Edward Thelwall1, Roy Taylor1, Sally M. Marshall2 1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom; 2Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom We have applied MR imaging methods to diabetic kidney disease by investigating the differences in kidney structure, blood flow and oxygenation between volunteers with Type 1 diabetes with and without diabetic nephropathy, and in non-diabetic control subjects. We hypothesised that early changes in kidney structure and function caused by diabetic nephropathy could be identified by altered renal structure, blood flow, and changes in oxygenation on water loading. Differences in renal artery flux were observed between volunteer groups. 2678. Renal Perfusion Imaging with FAIR and FIESTA at 3.0T MR Jing Wang1, Dongdong Liu2, Xuedong Yang3, Yi Dang1, Xiaoying Wang, 1,3, Jue Zhang1,2, Jing Fang1,2 1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; 2College of Engineering, Peking University, Beijing, China; 3Dept.of Radiology, Peking University First Hospital, Beijing, China Although Arterial Spin Labeling (ASL) being a non-invasive detection method has been used for many years, the respiratory and cardiac motions present major challenges when applying ASL. In this study, to measure the renal blood flow (RBF), a new abdominal ASL method was proposed by using single-shot fast imaging employing steady-state acquisition (FIESTA) combined with flow-sensitive alternation inversion recovery (FAIR) perfusion preparation on clinical 3.0T MR scanner. Results showed that the proposed technique had the ability to satisfy the renal perfusion quantification requirements, and the low renal perfusion area was also revealed clearly in a patient with an angioleiomyolipoma. 2679. DCE-MRI of the Kidney Using BLADE a Feasibility Study Florian Lietzmann1, Frank G. Zöllner1, Henrik J. Michaely2, Stefan Haneder2, Ulrike Attenberger2, Lothar Rudi Schad1 1Department of Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Mannheim, Germany Dynamic contrast enhanced MRI (DCE-MRI) provides a modern technique to assess physiological parameters like renal blood flow or glomerular filtration rate. The self-navigating BLADE-sequence with a certain robustness to motion artefacts in combination with an injection of a contrast agent offers an approach for a motion corrected DCE-examination without the need of respiratory triggering. The purpose of this study was to compare the T1-weighted BLADE sequence to the MR- gold standard TFL-sequence in clinical routine. Nathan S. Artz1, Kevin Johnson1, Yin Huang1, Elizabeth A. Sadowski2, Sean B. Fain1,2 1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Radiology, University of Wisconsin-Madison, Madison, WI, United States Quantifying arterial spin labeling (ASL) perfusion measurements using data acquired at only one delay time requires assumptions for quantification that may be invalid, especially in diseased kidneys which may demonstrate a wide variety of blood flows. The purpose of this study was to demonstrate the feasibility of efficiently acquiring data at multiple delay times using a radial balanced SSFP approach. ASL-FAIR was performed in a healthy volunteer at 1.5 T during which unique radial projections were continually acquired from 0.2 to 2 seconds following inversion. Twenty delay time images were acquired over 11 minutes. The control and tag images show reasonable image clarity and the difference images clearly demonstrate perfusion however streaking is originating from below the left kidney (right side). Future work will focus on reducing the streak artifact using motion compensation techniques and/or optimizing k-space trajectories. Matthew J. Kuhn1, Bryce K. Young1, N S. Mamillapalli2, Kalyani Vallurupalli3 1Radiology, University of Illinois at Peoria, Peoria, IL, United States; 2Radiology, Southern Illinois University, Springfield, Ilinois, United States; 3Radiology, Southern Illinois University, Springfield, IL, United States As part of an ongoing prospective multicenter study to determine the incidence of NSF in patients with stages 3 to 5 chronic kidney disease (CKD) undergoing magnetic resonance imaging (MRI) of the central nervous system with gadobenate dimeglumine, 223 patients have been enrolled at 15 sites. Patients are followed for 2 years with a regular schedule of telephone calls and visits. To date, no case of NSF has been reported, although follow-up is ongoing in most of these patients. 2682. Low-Dose Contrast-Enhanced Time-Resolved Renal MRA Hyun Jong Jeong1, James C. Carr2, Timothy J. Carroll1,2 1Biomedical Engineering, Northwestern University, Chicago, IL, United States; 2Radiology, Northwestern University, Chicago, IL, United States Dynamic imaging of the kidneys using MR offers non-invasive information about the renal anatomy and function. However, despite many improvements in renal MRA, there is a need for higher temporal resolution in time-resolved MRA, while minimizing the risks associated with gadolinium based contrast agents. In this study, low-dose renal MRA was performed using the previously developed CAMERA technique to achieve higher temporal resolution without undersampling. Francois Lazeyras1,2, Leo Buhler3, Antonio Nastasi3, Raphael Ruttimann3, Philippe Morel3, Jean-Bernard Buchs3 1Service of Radiology, University of Geneva and University Hospital of Geneva, Geneva, Switzerland; 2Center for Biomedical Imaging (CIBM), Lausanne and Geneva, Switzerland; 3Visceral and Transplantation Service, University of Geneva and University Hospital of Geneva, Geneva, Switzerland In this study, we compare 2 cold storage conditions for transplantation using 31P CSI: Oxygenated pulsatile perfusion (O2+HPP) performed immediately after kidney harvesting vs. simple cold storage (CSS). We found that ATP did not fully recovered after 8 hours of CSS, and PME/Pi time constant was similar in both conditions (~0.05 h-1). Assessment of PME and ATP kinetics are important in the context of organ evaluation before transplantation as they may be considered as markers of kidneys viability. 2684. Measuring Glomerular Protein Leakage with Dual-Agent DCE-MRI: Reproducibility in Healthy Pigs Mike Notohamiprodjo1, Michael Pedersen2, Klaus-Peter Lodemann3, Maximilian F. Reiser, Christian Glaser, Steven P. Sourbron 1Institute for Clinical Radiology, University Hospitals Munich, Munich, Bavaria, Germany; 2Skejby Sygehus Aarhus, Aarhus, Denmark; 3BRACCO S.p.a.
In this study a method is proposed to detect albumin leakage across the glomerular membrane with DCE-MRI. Four healthy piglets were examined with a dual-agent protocol with the contrast agent Gd-DTPA and the albumin-bound Gd-BOPTA. The small variability in the GFR values indicates that the measurement approach may be sufficiently precise to detect subtle variations in Gd-BOPTA relaxivity due to increased albumine leakage. This technique may help detecting such diseases in an early stage, where tubular reabsorption of albumine masks the leakage in urine samples. Further studies in a model with albumine leakage is warranted. 2685. Counting Total Number of Kidney Glomeruli Using MRI Scott Charles Beeman1, Megan Henriksen1, David Frakes1, Kevin M. Bennett1 1Bioengineering, Arizona State University, Tempe, AZ, United States We present a method for counting number of renal glomeruli using MRI. Rats were given intravenous injections of CF followed by resection of kidneys. Ex vivo Imaging revealed spots of hypointensity throughout the cortex of the kidney due to accumulation of CF in the glomerular basement membrane, consistent with individual glomeruli. Thresholding techniques applied to the image volumes yielded a glomerular count of 43,362 glomeruli. This is in agreement with and lies within 10% of a histological count of 39,514 glomeruli in the contralateral kidney, indicating an accurate glomerular count of the whole kidney. 2686. Segmentation of Kidney Cortex and Medulla on MR Images by Use of Multi-Feature K-Means Method Yin Huang1, Deborah Yagow2, Nathan Artz1, Elizabeth Sadowski3, Arjang Djamali4, Sean Fain1 1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 2Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States; 4Nephrology, University of Wisconsin-Madison, Madison, WI, United States The K-means segmentation method was implemented to automatically segment kidney cortex and medulla on MR images of 24 subjects based on two kidney feature values -- T1 and perfusion weighted information. Manual segmentation results on the same subjects were used as reference and three similarity measures were calculated to evaluate the effectiveness of K-means segmentation. The segmentation time was radically shortened by K-means compared with manual operation. However, there are about 30% of all subjects that K-means segmentation did not work well so that a semi-automated strategy can be suggested to incorporate manual segmentation when necessary. 2687. Changes in Kidney Volume in Experimental PKD Quantified by a Clinical 3T MR Scanner Sheryl Foster1, Mayuresh S. Korgaonkar2, Gopi K. Rangan3, Kristina G. Schwensen3, Anthony Peduto1 1Radiology, Westmead Hospital, University of Sydney, Australia; 2Brain Dynamics Center, Westmead Millennium Institute, Westmead, NSW, Australia; 3Centre for Transplant and Renal Research, Westmead Millennium Institute, University of Sydney, Australia The goal of this study was to assess the feasibility of using a 3T whole body clinical scanner along with a conventional available wrist coil in a longitudinal study of drug treatment in small rodents. We studied longitudinal kidney structural changes in rodents with Polycystic Kidney Disease (PKD); and also evaluated the effect of sirolimus treatment, an immunosuppressant drug currently used in clinical trials in humans with PKD, during early disease on the progression of kidney enlargement in this animal model. Colleen Bailey1,2, Mostafa Atri3, Georg A. Bjarnason1, Greg J. Stanisz1,2 1Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 2University of Toronto, Toronto, ON, Canada; 3University Health Network, Toronto, ON, Canada Patients with renal cell carcinoma were scanned with DCE-MRI (temporal resolution 3.7 s) and DCE-CT (temporal resolution 1 s). ROIs across the tumour volume were analyzed using the Kety-Tofts two-compartment model of perfusion. The volume transfer constant, Ktrans, did not correlate between the two modalities. The extravascular extracellular volume, ve, showed weak correlation. Undersampling the DCE-CT data to similar temporal resolution as the DCE-MRI data systematically underestimated Ktrans, whereas restricting the DCE-MRI data, initially acquired over five minutes, to the two minute acquisition time of the DCE-CT data resulted in a systematic underestimation of ve and an overestimation of Ktrans. 2689. Seminal Vesicle Dilatation in Autosomal Dominant Polycystic Kidney Disease Beatriu Reig1, Jon Blumenfeld2,3, Stephanie Donahue3, Wei Zhang, Martin R. Prince 1Department of Radiology, Weill Cornell Medical College, New York, NY, United States; 2Department of Medicine, Weill Cornell Medical College; 3The Rogosin Institute Seminal vesicle dilatation, a probable cause of infertility in men with autosomal dominant polycystic kidney disease (ADPKD), is characterized in this review of 47 male ADPKD patients undergoing MRI. Comparison is made to a cohort of age-matched controls. Masayuki Yamaguchi1, Natsumaro Kutsuna2,3, Ryutaro Nakagami1,4, Akira Nabetani5, Atsushi Nozaki5, Mamoru Niitsu4, Seiichiro Hasezawa2,3, Hirofumi Fujii1,3 1Functional Imaging Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan; 2Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan; 3Institute for Bioinformatics Research and Development-Japan Science and Technology Agency, Chiyoda, Tokyo, Japan; 4Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, Japan; 5GE Healthcare Japan, Hino, Tokyo, Japan Seminiferous tubules are stratified epithelia composed of germ cells and Sertoli cells. They produce sperm and normally are 200E00μm in diameter. We have succeeded in visualizing rat seminiferous tubules on in vivo MRI using a 3T scanner. In addition, the machine-learning technique allowed automatic classification of testicular regions on MRI into normal and abnormal spermatogenesis in chemotherapy-induced injury in rat testes. If these techniques are implemented in clinics in the future, they will be a helpful tool in reproductive medicine for infertile males. 2691. A Reference Region Tracer Distribution Model Analysis of Rat Penile Vascular Changes by DCE. H. Carl Le1, Nelson Bennett2, Raanan Tal2, Dov Winkleman1, John Mulhall3, Jason Koutcher1,4 1Medical Physics, MSKCC, New York, NY, United States; 2Urology, MSKCC, New York, NY, United States; 3Surgery, MSKCC, New York, NY, United States; 4Medicine, MSKCC, New York, NY, United States Sildenafil is effective in restoring penile blood flow in alleviating erectile function, a common side effect from radical prostatectomy. We have used DCE MRI to image rat corpora cavernosum post nerve injury with and without sildenafil treatment. The effect of sildenafil on the corpora cavernosal vascular volume changes are detected and can be used to monitor penile vascular health in clinic. Jian Wang1, Jian-ping Lu1, Tom W J Scheenen2 1Radiology, Changhai Hospital, Shanghai, China; 2Radiology, Radboud University Medical Centre Nijmegen, Nijmegen, Gelderland, Netherlands The quality of data acquisition and post-processing of proton MRSI with and without an endorectal coil at 1.5T and 3.0T was assessed with the use of a prostate phantom. With fixed spine and body array surface coils and an endorectal coil, 3D MRSI was performed repeatedly with 1) all coils, 2) only endorectal coil and 3) only surface coils. The choline + creatine/citrate (CC/C) ratio of each voxel was semi-automatically calculated and compared between different coil use and field strengths. Significant differences in CC/C existed between different field strengths and different locations within the phantom, when these locations had large differences in magnetic field homogeneity. Kyongtae Ty Bae1, Jung-Hwan Kim1, Alessandro Furlan1, Chan Hong Moon1, Bumwoo Park1, Tiejun Zhao2 1University of Pittsburgh, Pittsburgh, PA, United States; 2MR Research Support, Siemens Healthcare, Pittsburgh, PA, United States We have demonstrated the feasibility of 1H and 23Na imaging of in vivo human prostate using dual-tuned body surface Tx/Rx and endorectal Rx only coils. Our imaging technique was tested on normal human volunteers. Further improvement of this technique may facilitate the diagnosis of prostate cancer. Hai-Ling Margaret Cheng1,2, Syed S. Islam3, Yasir Loai3, Roula Antoon3, Marine Beaumont1, Walid A. Farhat3 1Research Institute & Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 3Division of Urology, The Hospital for Sick Children, Toronto, Ontario, Canada Cell-seeded natural tissue scaffolds hold promise for tissue-engineering large organs (e.g. the urinary bladder matrix for regenerating different tissue types). However, our understanding of cell-natural matrix interaction is limited, and its influence on MRI characterization is unknown. This study explores quantitative MRI at 1.5 T for investigating cell-matrix interaction and matrix development in a smooth muscle cell-seeded bladder model. Competing with cell presence was matrix degradation due to cell-released collagenase, noted for the first time and perhaps unique to natural matrices. Quantitative T1, T2, and diffusion measurements are consistent with collagen breakdown, with multicomponent T2 providing the best specificity. 2695. The Acellular Matrix for Bladder Tissue-Engineering: A Quantitative MRI Study Hai-Ling Margaret Cheng1,2, Yasir Loai3, Marine Beaumont1, Walid A. Farhat3 1Research Institute & Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 3Division of Urology, The Hospital for Sick Children, Toronto, Ontario, Canada Scaffolds derived from natural tissue acellular matrix (ACM) possess native biomechanical and biological properties difficult to achieve with synthetic materials. Despite their promise, ACM optimization is needed and remains in early development. This study investigates the bladder ACM, which is useful for regenerating various tissues, and effects of incorporating hyaluronic acid (HA), a natural biomaterial useful in tissue regeneration. Quantitative MRI measurements (T1, T2, diffusion) at 1.5 Tesla are consistent with HA presence and two-fold water uptake from HA incorporation, with multicomponent T2 distinguishing the two effects. These results provide baseline MRI data for studying further manipulation such as cell-seeding. Tumor Therapy Response Hall B Monday 14:00-16:00 Kim Anne Radermacher1, Sébastien Boutry2, Isabelle Mahieu2, Sophie Laurent2, Luce Vander Elst2, Caroline Bouzin3, Julie Magat1, Vincent Grégoire4, Olivier Feron3, Robert N. Muller2, Bénédicte F. Jordan1, Bernard Gallez1 1Biomedical Magnetic Resonance Unit, Catholic University of Louvain, Bruxelles, Belgium; 2NMR and Molecular Imaging Laboratory, University of Mons, Mons, Belgium; 3Unit of Pharmacology and Therapeutics, Catholic University of Louvain, Bruxelles, Belgium; 4Center for Molecular Imaging and Experimental Radiotherapy, Catholic University of Louvain, Bruxelles, Belgium The aim was to develop a molecular marker for non invasive monitoring of tumor cell death as a response to treatment. The phosphatidylserine-targeted peptide E3 was coupled to ultrasmall particles of iron oxide (USPIO). The USPIO concentration was evaluated in irradiated and untreated tumors by EPR and MRI in vivo. We also compared USPIO-E3 accumulation in three different tumor models presenting different degrees of radiosensitivity (fibrosarcoma is less radiosensitive than hepatocarcinoma which is less radiosensitive than lymphoma). The major finding of the present investigation is that USPIO-E3 allows the sensitive detection of tumor cell death after cytotoxic treatment. 2697. Evaluation of Radiotherapy Using Manganese-Enhanced MRI (MEMRI) Shigeyoshi Saito1,2, Sumitaka Hasegawa, Takako Furukawa, Tetsuya Suhara, Iwao Kanno, Ichio Aoki 1Graduate School of Medicine, Tohoku University, Sendai, Miyagi, Japan; 2National Institute of Radiological Sciences, Chiba, Japan Radiotherapy is the use of high-energy x-rays or particles to treat malignancies with the intention of destroying or inactivating cells while preserving normal tissue integrity. We found demonstrated that MEMRI ; 1) Cellular viability after radiation exposure could be evaluated usingsignal enhancementmanganese-labeling was reduced after x-ray irradiation for both in-vitro and in-vivo models. MEMRI may be used to evaluate the cellular viability of tumor after radiotherapy. Chad R. Haney1, Xiaobing Fan1, Gregory S. Karczmar1, Charles A. Pelizzari2, Marta Zamora1, Erica Markiewicz1, Helena J. Mauceri2, Ralph R. Weichselbaum2 1Radiology, University of Chicago, Chicago, IL, United States; 2Radiation & Cellular Oncology, University of Chicago, Chicago, IL, United States Ionizing radiation is a staple for treating tumors. However, failure to cure tumors is thought to be due to an intrinsic tumor cell radioresistance and its microenvironment. DCE-MRI was used to characterize the response of two tumor cell lines one radioresistant and the other radiosensitive. A genetically modified adenoviral vector was used, which causes infected cells to produce tumor necrosis factor alpha (a potent antivascular agent), only when irradiated. The radioresistant tumors showed no significant changes in the rate transfer constant and fractional volume accessible to the contrast agent. However, the radiosensitive tumors showed significant reduction in both kinetic parameters. Yuen-Li Chung1, Helen Troy1, Geoffrey S. Payne1, Marion Stubbs2, Ian R. Judson3, John R. Griffiths2, Martin O. Leach1 1CR-UK and ESPRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom; 2Cancer Research UK Cambridge Research Institute, Cambridge, United Kingdom; 3CR-UK Centre for Cancer Therapeutics, Institute of Cancer Research, Sutton, Surrey, United Kingdom Dichloroacetate (DCA) is a pyruvate dehydrogenase kinase (PDK) inhibitor and is found to be an anti-cancer agent. The aim of this work was to develop a non-invasive and robust biomarker for tumour response following PDK inhibition. In vivo and in vitro 1H- and 31P-MRS of HT29 xenografts and tumour extracts were used. DCA treatment caused tumour growth inhibition and altered phospholipid metabolism and tumour bioenergetics. The drop in total choline and phosphomonoesters may have potential as non-invasive markers for tumour response following treatment with DCA or other PDK inhibitors. Jack van Asten1,2, Tone F. Bathen3, Tessa Buckle4, Chantal Beekman4, Ingrid Gribbestad3, Fijs van Leeuwen4, Arend Heerschap1 1Radiology, Radboud University Nijmegen Medical Center, Nijmegen, Netherlands; 2Biophysical Chemistry, Radboud University Nijmegen, Nijmegen, Netherlands; 3Dept. of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway; 4Radiology and Nuclear Medicine, Division of Diagnostic Oncology, The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital Breast cancers may be resistant to docetaxel treatment. We investigated the metabolic profile of breast cancer tissue in mouse strains resistant and sensitive to treatment by docetaxel. A typical choline compound profile was found to be predictive for treatment efficiency. Tammy Louise Kalber1, Gavin D. Kenny1, Nazila Kamaly1,2, Willy Gsell3, Marzena Wylesinska-Arridge3, Leigh P. Brody1, Andrew D. Miller2, Jimmy D. Bell1 1Metabolic and Molecular Imaging Group, Imaging Sciences Department, MRC, Imperial College London, Hammersmith Hospital, London, United Kingdom; 2Imperial College Genetic Therapies Centre, Department of Chemistry, Imperial College London, London, United Kingdom; 3The Biological Imaging Centre, Imperial College London, London, United Kingdom Human colon adenocarcinoma cells, transfected to overexpress inducible nitric oxide synthase (iNOS) were used to characterize the delivery of iNOS siRNA by bimodal liposomes in vitro and in vivo. Incubation in vitro resulted in a significant decrease in nitrite by day 72. Whereas, iNOS overexpressing tumours administered with iNOS siRNA liposomes resulted in decreased T1 over 24 hours, consistent with gradual accumulation within the tumour. Tumour volume measurements showed growth restriction and regression suggestive of siRNA release resulting in gene silencing and therapeutic effect after ~ 5 days. However, DCE-MRI was not able to evaluate changes in tumour perfusion leading. Enrico C. Lallana1, Kyle A. Brong2, Khan Hekmatyar1, Neil Jerome1, Martin Wilson3, Camilo E. Fadul1, Risto A. Kauppinen4 1Dartmouth Medical School; 2Dartmouth College; 3University of Birmingham; 4Dartmouth Medical School, Hanover, NH, United States A rodent anti-VEGF-antibody, B20-4.1.1, was used to treat orthotopic 9L glioma bearing rats. During the first week of treatment kinetics of T1-weighted signal enhancement following rapid Magnevist iv-bolus slowed down greatly, reflecting reduced vascular leakiness and perfusion. At the same time, 1H MRS showed large increase both in relative lactate and 1.3ppm and 0.9ppm lipids, while water diffusion in treated gliomas was unchanged. These results indicate that 1H MRS provides endogenous imaging biomarkers for tumour cell responses during anti-angiogenic therapy, that are not obtained by contrast enhanced MRI or diffusion. 2703. In Vivo MR Detection of Inhibition of Signaling Transduction in Non-Hodgkin's Lymphoma Seung Cheol Lee1, Michal Marzec2, Xiabin Liu2, Suzanne Wehrli3, Mariusz Wasik2, Jerry David Glickson1 1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, United States; 3NMR Core Facility, Children's Hospital of Philadelphia, Philadelphia, PA, United States More and more drugs for cancer are being developed in the context of signaling transduction. Some of such drugs are already in clinical trial. A noninvasive method to early detect the effect of these drugs is demanding. NMR is a promising candidate to meet this request as it can be applied in vivo to measure metabolic perturbations in tumors following various therapies. We're investigating to see effects of the inhibitor of mammalian target of rapamycin (mTOR) which is a highly conserved serine/threonine kinase that controls cell growth and metabolism in response to nutrients, growth factors, cellular energy, and stress. 2704. Preclinical Therapeutic Sequencing Using a Dual-Tracer Multi-Animal DCE-MRI Platform James A. Bankson1, David L. Schwartz2, Douglas Webb1, Charles V. Kingsley1, Jorge Delacerda1, Marc S. Ramirez1, Garth Powis1 1Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX, United States; 2Department of Radiation Medicine, North Shore-LIJ Health System, New Hyde Park, NY, United States A dual-tracer multi-animal DCE-MRI platform has been used to compare response of a xenograft model of pancreatic cancer to combinations of radiation therapy and PX-478, a novel selective HIF-1a inhibitor currently in Phase I clinical trial. Six groups of eight animals were administered sham, single-agent, concurrent, or sequential therapies. Dual-tracer multi-animal DCE-MRI evaluation of vascular changes detected most pronounced response in group given combined therapy compared to controls as early as +3d after completion of therapy, preceding detectable differences in tumor growth by >7d. The dual-tracer multi-animal DCE-MRI platform enabled high-throughput evaluation of response to therapy. 2705. Theranostic Effect of Serial MEMRI on the HESC Induced Teratoma Jaehoon Chung1, Rajesh Dash1, Kehkooi Kee2, Joelle Barral3, Irving Weissmann4, Dwight Nishimura3, Robert Robbins5, Renee Reijo Pera2, Phillip C. Yang1 1Cardiovascular medicine, Stanford University, Stanford, CA, United States; 2Stem cell biology and regenerative medicine, Stanford University, Stanford, CA, United States; 3Electrical engineering, Stanford University, Stanford, CA, United States; 4Pathology, Stanford University, Stanford, CA, United States; 5Cardiothoracic surgery, Stanford University, Stanford, CA, United States Systemic administration of MnCl2 enabled simultaneous monitoring and selective elimination of hESC induced teratoma cells by higher intracellular accumulation of Mn2+. This is the first study to demonstrate MEMRI has a theranostic effect in both detecting and eliminating early teratoma formation. 2706. MRI Molecular Imaging Monitors Downstream Anti-Angiogenic Effects of MTOR Inhibition Robert Ross1, Jose L. Figueiredo2, Peter Waterman2, Ralph Weissleder3, Alexander R. Guimaraes4,5 1Lank Center for Genitourinary Oncology, Dana Farber Cancer Institute, Boston, MA, United States; 2Center for Systems Biology, Massachusetts General Hospital, Boston, mA, United States; 3Center for Systems Biology, Massachusetts General Hospital, Boston, MA, United States; 4Radiology, Massachusetts General Hospital/Martinos Center for Biomedical Imaging, Charlestown, MA, United States; 5Center for Systems Biology, Massachusetts General Hospital/Martinos Center for Biomedical Imaging, Boston, mA, United States Inhibitors of the mammalian target of rapamycin (mTOR) are approved in patients with metastatic renal cell cancer (RCC). Our aim was to evaluate in vivo, mTOR inhibition on the vascularity of a RCC mouse model using magnetic nanoparticle enhanced MRI and to compare these effects to the established VEGF inhibitor, sorafenib. There was excellent correlation (R^2 0.95) of MRI measures of vascular volume fraction to histologic microvessel density . VVF in all treatment arms differed from control (p<0.05) at end of therapy. This study demonstrates that MRI can monitor noninvasively, the in vivo antiangiogenic effects of chemotherapeutic agents. 2707. The Effects of SDF-CXCR4 Signaling on Tumor Growth: The Involvement of Neural Progenitor Cells Nai-Wei Yao1, Chiao-Chi V. Chen1, Chen Chang1 1Functional and Micro-magnetic Resonance Imaging Center, Institution of Biomedical Sciences, Academia Sinica, Taipei, Taiwan Neural progenitor cells (NPCs) and glioma cells share many common features, including the expression of several cellular markers (such as nestin and CD133), a robust proliferative potential, and pluripotency. The present study demonstrates that tumors exhibited rapid growth following NPCs transplantation while the migration was promoted by the signaling of the stromal cell”Vderived factor-1 (SDF-1) / CXC chemokine receptor 4 (CXCR4) axis. The finding identified a role of NPCs in tumor expansion. Kimberly R. Pechman1,2, Deborah L. Donohoe, 2,3, Devyani P. Bedekar, 2,3, Kathleen M. Schmainda, 2,4 1Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States; 2Translational Brain Tumor Program, Medical College of Wisconsin, Milwaukee, WI, United States; 3Radiology, Medical College of Wisconsin, Milwaukee, WI, United States; 4Radiology and Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States Few systematic studies have been performed to determine the optimal timing for combining anti-angiogenic therapy with chemotherapy for the treatment of brain tumors. Standard MRI measures of enhancing tumor volume are not appropriate since anti-angiogenic drugs decrease contrast enhancement. The purpose of this study was to evaluate the utility of using rCBV, derived from DSC imaging, to optimize the combination of bevacizumab and irinotecan for the treatment of brain tumors. The studies, performed in the U87 brain tumor model, demonstrate that the optimal combination, occurs when irinotecan is administered two days before or after treatment with bevacizumab. Andreas Steingoetter1,2, Jonas Svensson3, Yvonne Kosanke1, Ernst Rummeny1, Rickmer Braren1 1Institute of Radiology, Klinikum rechts der Isar der TU München, Munich, Germany; 2Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; 3Department of Medical Radiation Physics, Malmo University Hospital, Lund University, Malmo, Sweden A limitation in DCE-MRI is the difficulty of simultaneous measurement of arterial input function and CA concentration in tumor tissue. In this study, two anaesthesia protocols, resulting in a ~ 30% change in heart rate, were used to simulate systemic changes in AIF to analyze the robustness of popAIF vs RR modeling in an orthotopic HCC rat tumor model. Different anaethesisa protocols resulted in a significant systematic offset for popAIF based ktrans and ve modeling compared to RR. This study highlights the robustness and feasibility of the reference region approach. Benedicte F. Jordan1, Julie Peeterbroeck1, Oussama Karroum1, Caroline Diepart1, Julie Magat1, Vincent Gregoire2, Bernard Gallez1 1Biomedical Magnetic Resoncance Unit, Universite Catholique de Louvain, Brussels, Belgium; 2IMRE, Universite Catholique de Louvain EPR and 19F-MRI oximetry were used to monitor acute changes in tumor hemodynamics after administration of potential NO-mediated radiation co-treatments. For this purpose, S-nitrosocaptopril, a converting enzyme inhibitor with vasodilatory properties combined to a nitric oxide donor, was tested in experimental tumors. Tumor oxygenation was significantly increased 30 minutes after administration of the co-treatment. This effect was the result of an increase in tumor blood flow along with a decrease in tumor oxygen consumption by tumor cells. This oxygen effect contributed to the increase in efficacy of radiation therapy with 10Gy of X-rays, an effect that was not observed with captopril alone. 2711. In Vivo and in Vitro MR Biomarkers for Choline Kinase Inhibition in Human Colon Cancer HCT-116 Moses Darpolor1, Peter Kennealey2, H. Carl Le1, Kristen Zakian1, Ellen Ackerstaff1, Asif Rizwan1, Jin-Hong Chen2, Eliot Sambol2, Gary Schwartz3, Samuel Singer2, Jason Koutcher1,3 1Medical Physics, MSKCC, New York, NY, United States; 2Surgery, MSKCC, New York, NY, United States; 3Medicine, MSKCC, New York, NY, United States Combined irinotecan and flavopiridol therapy is in clinical trials to treat human colon malignancies. Using in vivo and in vitro MR measurements we report here several critical HCT-116 cellular markers from the treatment. We have shown that flavopiridol is effective in inhibiting choline kinase by lowering phosphocholine/choline levels in vitro, while 31P MRSI detected an in vivo transient decrease in phosophocholine level following the treatment with both drugs. Detectable cholesterol/CH3 levels were observed to increase in tandem with HCT-116 cancer cell apoptotic fraction. Warren Foltz1, Caroline Chung1, Jesper Kallehauge1, Kelly Burrell2, Patricia Lindsay1, David Jaffray1, Gelareh Zadeh2, Cynthia Ménard1 1Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada; 2Brain Tumor Research Centre, University Health Network, Toronto, Ontario, Canada ADC can monitor early tumor response to cytotoxic therapy and predict clinical outcomes. This study monitored early ADC response and tumor growth following sunitinib and/or radiotherapy in a murine intracranial model of human glioblastoma multiforme. Imaging proceeded at 3-7 day intervals following base-line MRI and image-based stratification into treatment arms. RT trial arms demonstrated considerable early ADC elevation, and persistent elevation during growth delay. Sunitinib monotherapy maintained ADC below other arms, and constrained tumor growth. Control animals displayed moderate ADC elevation and earliest exponential tumor growth. Early ADC changes may be a useful biomarker of treatment response and growth delay. Gavin David Kenny1, Tammy Louise Kalber1, Nazila Kamaly1,2, Leigh Pauline Brody1, Andrew David Miller2, Jimmy David Bell1 1Metabolic and Molecular Imaging Group, Imperial College, London, United Kingdom; 2Genetic Therapies Centre, Imperial College, London, United Kingdom Survivin is a gene upregulated in the majority of cancers, but not expressed in normal tissue and is therefore a possible target for tumour therapy. In this study siRNA targeted to Survivin was encapsulated in to liposomes and the delivery to the tumour monitored using MRI and corroborated by fluorescence microscopy. The Survivin siRNA delivered by the liposomes significantly reduced the growth rate of the tumours for at least 72 hours when compared to a control siRNA and therefore could potentially be used as a cancer therapy. 2714. Evaluation of Diffusion MR as a Biomarker for Nanoparticle Therapy Response in Lymphoma Thomas Sheung Chee Ng1,2, Daniel Procissi1, Hargun Sohi1, Andrew A. Raubitschek3, Russell E. Jacobs1 1California Institute of Technology, Pasadena, CA, United States; 2University of Southern California, Los Angeles, CA, United States; 3Beckman Institute, City of Hope, Duarte, CA, United States IT-101 is a novel nanoparticle therapy that specifically targets the tumor mass. We evaluated whether diffusion MR is sensitive to early IT-101 response in a mouse model of lymphoma. Lauren CJ Baker1, Jessica KR Boult1, Yann Jamin1, Simon Walker-Samuel1, Margaret A. Ashcroft2, Simon P. Robinson1 1CR-UK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, United Kingdom; 2University College London, London, United Kingdom The hypoxia-inducible factor pathway (HIF) is a key regulator in tumor cell adaptation to the hypoxic microenvironment. Small molecule HIF inhibitors have been identified and are currently being evaluated in vivo using non-invasive magnetic resonance (MR) methods. In this study, we show that diffusion-weighted magnetic resonance imaging (DW-MRI) can detect tumor response to the HIF pathway inhibitor NSC-134754 24h post administration in a murine orthotopic model of prostate cancer. Complimentary ex vivo histology of parameters including hypoxia, perfused vessels and necrosis further provided an insight into tumor physiology and microenvironment alterations induced by NSC-134754. 2716. Multi-Parametric Imaging of Tumor Treatment Response to VEGF Blockade Benjamin A. Hoff1, Mahaveer S. Bhojani2, Alnawaz Rehemtulla2, Brian D. Ross1, Craig J. Galban1 1Radiology, University of Michigan, Ann Arbor, MI, United States; 2Radiation Oncology, University of Michigan This study investigates permeability and diffusion-weighted imaging as surrogate biomarkers of tumor response to anti-angiogenic therapy. Vascular permeability, and plasma volume fractions and apparent diffusion coefficient (ADC) maps were acquired pre and post treatment initiation of VEGF-Trap, an anti-angiogenic agent, or vehicle in a rodent glioma model. Permeability parameters dropped significantly following treatment, whereas ADC, an indirect measure of cellularity, remained unchanged. Confirmed by histology, tumor cellularity were consistent between groups, whereas, vascular disruption was visible in treated animals resulting in a drop in cell proliferation as determined by ki-67. Warren Foltz1, Andy Wu1, Masoom Haider2,3, Peter Chung1, Andrew Bayley1, Charles Catton1, Cynthia Ménard1 1Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada; 2Medical Imaging, University Health Network, Toronto, Ontario, Canada; 3Medical Imaging, University of Toronto Apparent diffusion coefficent (ADC) increases with cytoxic interventions, and may provide an early response biomarker for prostate radiotherapy. This study evaluated prostate zonal and tumor ADC using clinically normal and high b-values in low/intermediate risk patients at baseline and at 2-week intervals throughout their 8-week radiation treatment. Central gland ADC elevated moderately but significantly throughout treatment, while uninvolved peripheral zone ADC trended towards a late reduction. Tumor ADC was elevated in all follow-up scans, to 15% at week 8. SNR analysis at each b-value identified the minimum region volume for noise-insensitive measurements, to guide protocol design for future voxel-based assessment. Martin Zweifel1, Daniel Patterson1, N J. Taylor2, J J. Stirling2, David J. Collins3, James A. d'Arcy3, Martin O. Leach3, Gordon J. Rustin1, Anwar R. Padhani2 1Medical Oncology, Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, United Kingdom; 2Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, United Kingdom; 3CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research & Royal Marsden Hospital, Sutton, Surrey, SM2 5PT, United Kingdom This is a report of the first, in man study of serial BOLD MRI after a vascular disruptive agent in a translational phase I clinical trial of OXi4503. Changes observed in R2* were used to define onset of VDA activity and results are compared to DCE-MRI changes at 4 hours. R2*showed significant VDA within the 1st few hours. Both R2*and DCE-MRI show positive dose-response relationships. If both R2*and DCE-MRI parameters are used to assess OXI4503 activity (by significant increases in R2*and decreases in Ktrans/IAUGC60), then 52% of lesions show MRI changes consistent with VDA effect. 2719. Comparison of Diffusion and DCE-MRI as Markers for Response to Therapy in HCC Patients Edward Andrew Ashton1, Renuka Iyer2 1R&D, VirtualScopics, Inc., Rochester, NY, United States; 2Oncology, Roswell Park Cancer Center, Buffalo, NY, United States This study assessed ADC measurement as a marker for response in oncology trials. An evaluation of variability in ADC in liver tissue was carried out using twelve volunteers. Results showed that ADC can be measured in liver with CoV < 10%. Subsequently, ADC changes from baseline were measured in HCC patients after therapy with an anti-angiogenic agent and/or chemoembolization. Ktrans measurements were also obtained for these patients using DCE- MRI, which is known to be a good marker for changes associated with these therapies. Results show that changes in Ktrans are highly correlated with changes ADC. Philip Stephen Murphy1, Caleb Roberts2, Brandon Whitcher3, Frank Stornanti4, Jennifer Gauvin5, Thomas Yau6, Pei-Jer Chen7, Martin Curtis5, Ben Suttle5, Thangam Arumugham5, Jeffrey Hodge5, Mohammed Dar5, Ronnie Poon6, Geoff JM Parker2 1Oncology Clinical R&D, GlaxoSmithKline, Uxbridge, Middlesex, United Kingdom; 2Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University of Manchester, Manchester, United Kingdom; 3Clinical Imaging Centre, GlaxoSmithKline, London, United Kingdom; 4Perceptive Informatics, Billerica, United States; 5Oncology Research, GlaxoSmithKline, Research Triangle Park, United States; 6Queen Mary Hospital, Hong Kong, China; 7National Taiwan University Hospital, Taipei, Taiwan When performing dynamic contrast enhanced MRI (DCE-MRI) in the dose-ranging setting, correlating the readout to individual pharmacokinetic (PK) parameters is more informative than relating to dose alone. In a study of the VEGF receptor inhibitor pazopanib in hepatocellular carcinoma (HCC), relationships between image-based measures of vascular function, PK parameters, and clinical activity were observed. 2721. Comparison of Tracer Kinetic Models with DCE-MRI to Evaluate a Phase 1 Anti-Angiogenic Trial Choon Hua Thng1, Tong San Koh2, Septian Hartono1, Bee Choo Tai3, Puor Sherng Lee1, Helmut Rumpel4, Ai Bee Ong5, Norita Sukri5, Chiung-Ing Wong5, Ross Soo5, Albert Su Chong Low4, Rod Humerickhouse6, Boon Cher Goh5 1National Cancer Centre Singapore, Singapore, Singapore; 2Nanyang Technological University, Singapore, Singapore; 3National University of Singapore, Singapore; 4Singapore General Hospital, Singapore; 5National University Hospital, Singapore; 6Abbott Laboratories, United States Dynamic contrast enhanced MRI (DCE-MRI) with tracer kinetic modeling has been proposed as a biomarker of angiogenesis imaging. Three tracer kinetic models were studied as methods of angiogenesis assessment: conventional compartmental (model developed by Brix et al. (1), adiabatic approach to tissue homogeneity model developed by St. Lawrence and Lee (2), and distributed parameter model developed by Koh et al. (3) All models enable derivation of tissue microcirculatory parameters such as blood flow and capillary permeability-surface area product. We aim to examine the association between the above parameters with drug exposure and patient outcome in a Phase I anti-angiogenic trial. Tumor Perfusion & Permeability Hall B Tuesday 13:30-15:30 Jacob Fluckiger1, Matthias Schabel, Ed DiBella 1Bioengineering, University of Utah, Salt Lake City, UT, United States The authors present a method for determining the accuracy of locally estimated arterial input functions in DCE-MRI. Preliminary results from clinical data are presented. Gene Young Cho1, Eric E. Sigmund1, Sungheon Kim1, Jens H. Jensen1, Daniel K. Sodickson1 1Center for Biomedical Imaging, Radiology, NYU School of Medicine, New York, United States Diffusion-weighted imaging (DWI) can be sensitized to both tissue structure and microvascular flow in tumors. Capillary networks can present intravoxel-incoherent motion (IVIM), creating a pseudodiffusion coefficient that tracks microvascular flow. A versatile flow phantom was constructed for IVIM validation in a full body 3T scanner. This system allows technique optimization for ongoing IVIM-based studies of in vivo tumor pathologies. Biexponential analysis of DWI showed an increase in pseudodiffusivity with increasing flow and a decrease with increased impedance, simulating relevant microvascular processes. Spatial mapping of the IVIM coefficients showed strong contrast between pseudodiffusion and background diffusion. Future applications are discussed. Jin Zhang1, Sungheon Kim2 1Department of Finance and Risk Engineering, Polytechnic Institute of New York University, New York, NY, United States; 2Center for Biomedical Imaging, Radiology, NYU School of Medicine, New York, NY, United States Extracting physiologically relevant parameters from DCE-MRI data is still a challenging problem since the effect of contrast agent is indirectly measured in proton MRI. The purpose of the current study was to use a numerical simulation method to generate DCE-MRI data with water exchange effect and to investigate its effects on the pharmacokinetic model parameters. Realistic MRI data were simulated using the BTEX model and a three-site two-exchange model. Two conventional pharmacokinetic models were fitted to the simulated data. The preliminary results demonstrate the significance of the water exchange effect in estimating pharmacokinetic model parameters. Jerome Cote1, Luc Tremblay1, Fernand Jr Gobeil2, David Fortin3, Martin Lepage1 1Nuclear medecine and radiobiology, Université de Sherbrooke, Sherbrooke, QC, Canada; 2Pharmacology, Université de Sherbrooke, Sherbrooke, QC, Canada; 3Surgery, Université de Sherbrooke, Sherbrooke, QC, Canada Dynamic contrast-enhanced magnetic resonance imaging with intravenous Gd-DTPA or Gadomer was used to monitor the selective increase of blood-brain barrier permeability (BBB) at the tumor of glioma-bearing rats, induced by either the natural kinin B1 receptor (B1R) agonist LDBK, or NG29, a synthetic high-affinity agonist. Post-contrast images revealed that only NG29 modulates topographic uptake profiles of both contrast agents within rat glioma and brain tissue surrounding the tumor, as observed by increase of both contrast agents distribution volume and mean Gd concentration in the implanted hemisphere. Our results confirm the use of B1R agonists to permeabilize the BBB around tumors. 2726. Towards Robust and Automated Identification of Vascular Input Function in DCE-MRI Kim Mouridsen1, Dominique Jennings1, Elisa Gelasca1, Elizabeth Gerstner1, Tracy Batchelor2, Gregory Sorensen1 1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States; 2Stephen E. & Catherine Pappas Center for Neuro-Oncology, Massachusetts General Hospital, Boston, MA, United States Dynamic contrast enhanced MRI (DCE-MRI) holds potential for characterizing key physiological markers of tumor vascularity such as blood brain-barrier-permeability. Reproducibility of pharmacokinetic parameters in multicenter settings is contingent on reliable characterization of the vascular input function (VIF). This is compromised by signal attenuating T2* effects at high concentrations and insensitivity of typical T1-weighted sequences at peak bolus passage, as well as non-reproducible manual identification of VIFs. We demonstrate that a completely automatic VIF identification procedure combined with T2* based estimation of peak concentration yields VIF reproducibility comparable to expert manual selection in two pre-treatment baseline scans of 10 glioblastoma patients. Ramesh Paudyal1, Hassan Bagher-Ebadian1,2, Swayamprava Panda1, Joseph D. Fenstemacher3, James R. Ewing1,2 1Neurology, Henry Ford Hospital, Detroit, MI, United States; 2Physics, Oakland University, Rochester, MI, United States; 3Anestheisology, Henry Ford Hospital, Detroit, MI, United States Contrast-enhanced (CE-MRI) utilizes T1 and T2* contrast mechanism and paramagnetic labeled contrast agents (CAs) to characterize the resultant kinetic parameters of cerebral tissue. In this study, the dynamic maps of the ratio of T2* and T1, i.e.Ć2 (the ratio of the relaxivities of T2* and T1), are employed to track the movement of the macromolecular CAs in tumors interstitium. The velocity wave fronts show the redistribution of CAs after extravasation in interstitium which allows monitoring the delivery of the chemotherapeutic agent in tissue Anita Banerji1,2, Josephine H. Naish1,2, Yvon Watson1,2, Giovanni A. Buonaccorsi1,2, Geoff J. Parker1,2 1Imaging Sciences and Biomedical Engineering, School of Cancer and Imaging Sciences, The University of Manchester, Manchester, United Kingdom; 2Biomedical Imaging Institute, Manchester, United Kingdom Healthy liver tissue has highly leaky sinusoids, a dual blood supply and can be characterised using the one-compartment dual-input Materne model, whereas the two-compartment single-input extended Kety model is often used to describe tumours that contain capillaries and have an arterial supply. We use the Akaike model selection criterion applied to dynamic contrast-enhanced MR data of liver tumours. We demonstrate that the extended Kety model is preferred within the tumour with a trend towards the Materne model within non-tumour liver tissue. This has implications for the identification of tumours in the liver and for partial volume errors. 2729. A Semi-Automated Method for Obtaining the Arterial Input Function in Dynamic Breast Data Xia Li1,2, E. Brian Welch3, A. Bapsi Chakravarthy4, Ingrid Mayer5, Mark Kelley6, Ingrid Meszoely7, Julie Means-Powell6, John C. Gore, 28, Thomas E. Yankeelov1,2 1Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; 2Institute of Imaging Science, Nashville, TN, United States; 3Philips Healthcare, Nashville, TN, United States; 4Radiation Oncology, Vanderbilt University; 5Medical Oncology, Vanderbilt University; 6Surgical Oncology, Vanderbilt University; 7Radiology, Vanderbilt University; 8Radiology and Radiological Sciences , Vanderbilt University, Nashville, TN, United States Quantitative analysis of dynamic contrast enhanced MRI (DCE-MRI) data requires the accurate determination of the time rate of change of the concentration of contrast agent, Cp, in the blood pool; what is typically referred to as the arterial input function, or AIF. While there have been several methods suggested for capturing AIF kinetics, many are difficult to apply in the particular case of breast cancer. Here, we propose a simple and effective approach to obtain the AIF from breast DCE-MRI data. The method is based on tracking an initial seed point placed within the axillary artery. 2730. Tissue Estimated Vascular Input Functions Improve DCE-MRI Model Fitting Michael Germuska1, Sophie Riches1, David Collins1, Geoffrey Payne1, Nandita deSouza1, Martin Leach1, Matthew Orton1 1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, London, United Kingdom Dynamic contrast enhanced MRI requires an estimate or measurement of the arterial input function (AIF) to model pharmacokinetic behaviour. To reduce the variability in a measured AIF, a population AIF is often used. Alternatively it is possible to obtain an AIF from local tissue. Pharmacokinetic models driven by AIFs extracted from the prostate tissue were compared to a population AIF for 12 prostate cancer patients. Tissue estimated AIFs were found to out performed the population AIF in terms of fitting residuals and variability in KTrans estimates. The results show tissue estimated AIFs can be used to improve DCE-MRI model fitting. 2731. Identification of Hypoxic Regions In Vivo in the Prostate Radka Stoyanova1, Ellen Ackerstaff2, HyungJoon Cho2, Jason A. Koutcher2, Alan Pollack1 1Radiation Oncology, University of Miami, Miami, FL, United States; 2Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, United States We present an application of Pattern Recognition techniques to identify the characteristic temporal pattern of hypoxia in Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI). The approach is confirmed in DCE-MRI data from an animal model, acquired concurrently with several complementary imaging modalities including pimonidazole staining. The technique is also applied to DCE-MRI data from the tumor of a prostate cancer patient where a similar temporal pattern is uncovered in parts of the tumor. Our results suggest that by applying this approach we can potentially deconvolve the hypoxic temporal pattern in in vivo data from patients with prostate cancer. 2732. Assessment of Tumor Hypoxia with DCE-MRI: A Preclinical Study on Human Melanoma Tumor Lines Tormod André Mjelde Egeland1, Jon-Vidar Gaustad1, Berit S. Mathiesen1, Einar Kåre Rofstad1 1Department of Radiation Biology, The Norwegian Radium Hospital, Oslo, Norway Purpose: To study the potential usefulness of DCE-MRI for assessing the extent of tumor hypoxia. Methods: Gd-DTPA-based DCE-MRI was performed on human melanoma xenografts from 8 different tumor lines grown orthotopically in mice. ve and Ktrans from Tofts model were obtained on a voxel-by-voxel-basis, and compared with the radiobiologically hypoxic fraction (HFrad). Results: A strong linear correlation between ve and HFrad (p<0.002 for all quartiles) and a non-linear relationship between Ktrans and HFrad was found. Conclusions: This study suggests that it may be possible to obtain information on tumor oxygenation in patients from DCE-MRI studies. Pierluigi Di Giovanni1, Trevor Sean Ahearn1, Scott I K Semple2, Che A. Azlan1,3, Fiona J. Gilbert1, Thomas W. Redpath1 1Radiology, University of Aberdeen, Aberdeen, Scotland, United Kingdom; 2Medical Physics, University of Edinburgh, Edinburgh, Scotland, United Kingdom; 3Biomedical Imaging, University of Malaya, Kuala Lumpur, Malaysia Among the physiological features found in tumors is the increased interstitial fluid pressure (IFP). Dynamic contrast enhanced MRI (DCE-MRI) can be used to generate a parametric map of the volume transfer constant going from the intravascular space into the lesion interstitial space (Ktransin) and in opposite direction (Ktransout). We have studied the spatial distribution of the ratio Ktransout/Ktransin in breast cancers. Our parametric maps reveal that those tumors having a central non-enhancing region show a very similar pattern in the imbalance between the two transfer constants. We argue that what we observe is linked to the spatial distribution of IFP. Xia Li1, E. Brian Welch2, A. Bapsi Chakravarthy3, Lei Xu4, Mary Loveless5, Ingrid Mayer6, Mark Kelley7, Ingrid Meszoely8, Julie Means-Powell7, John C. Gore9, Thomas E. Yankeelov1 1Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; 2Philips Healthcare, Nashville, TN, United States; 3Radiation Oncology, Vanderbilt University; 4Biostatistics, Vanderbilt University; 5Biomedical Engineering, Vanderbilt University; 6Medical Oncology, Vanderbilt University; 7Surgical Oncology, Vanderbilt University; 8Radiology, Vanderbilt University; 9Radiology and Radiological Sciences , Vanderbilt University, Nashville, TN, United States The accurate determination of the arterial input function, or AIF, plays an important role to quantitative analysis of dynamic contrast enhanced MRI (DCE-MRI) data. We have proposed (in a separate abstract) a simple and efficient method to obtain the AIF, through tracking an initial seed point placed within the axillary artery. Using this method, we obtain the AIF for each individual patient (AIFind) and the population averaged AIF (AIFpop). We apply the AIFs to two DCE-MRI pharmacokinetic models to compare the physiological parameters. Caleb Roberts1,2, Josephine H. Naish1,2, Claire L. Mitchell3, Yvonne Watson1,2, Sue Cheung1,2, Gio A. Buonaccorsi1,2, Gordon C. Jayson3, John C. Waterton, 2,4, Jean Tessier4, Geoff J. Parker1,2 1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, The University of Manchester, Manchester, United Kingdom; 2The University of Manchester Biomedical Imaging Institute, The University of Manchester, Manchester, United Kingdom; 3Cancer Research UK Dept Medical Oncology, Christie Hospital and University of Manchester, Manchester, United Kingdom; 4AstraZeneca, Alderley Park, Macclesfield, Cheshire, United Kingdom While there is a good understanding of microvascular function and structure described by tracer kinetic model-based analyses of dynamic contrast-enhanced (DCE)-MRI data, the interpretation of apparent water diffusion coefficient (ADC) is less clear. Besides ADC, the parameter that is most sensitive to the water distribution and geometry is T1. In this study, we acquire DCE-MRI and diffusion weighted images from a group of ovarian tumors and find significant relationships between ADC, T1, and ve that offer insight into the physiological meaning of these parameters in ovarian tumors. 2736. A Method to Estimate Sample Sizes for DCE-MRI-Based Studies of Heterogeneous Tumors Chris James Rose1,2, James P. O'Connor1,2, Caleb Roberts1,2, Gio A. Buonaccorsi1,2, Yvon Watson1,2, Sue Cheung1,2, Gordon Jayson3, Geoff J. Parker1,2 1Imaging Science and Biomedical Engineering, The University of Manchester, Manchester, United Kingdom; 2The University of Manchester Biomedical Imaging Institute, Manchester, United Kingdom; 3Cancer Research UK and University of Manchester Department of Medical Oncology, The Christie Hospital, Manchester, United Kingdom DCE-MRI is of great utility for studying tumor microvasculature, particularly in early phase clinical trials. Most analysis methods assume homogeneous tumors, which is often incorrect and a problem when planning trials, because the magnitude of effect observed using DCE-MRI will be attenuated, for example, by contributions from necrotic tissue. By simulating maps of Ktransusing a model of tumor heterogeneity, we present a method to estimate the distribution of required sample size. We illustrate the methods application using data from a trial of bevacizumab in CRC metastases and show that by considering heterogeneity, more powerful studies can be planned. 2737. Simultaneous Vessel Size and Blood Volume Measurement in a Human Tumor Outside the Brain Stefanie Remmele1, Janine Ring2, Julien Sénégas1, Walter Heindel2, Wolfgang E. Berdel3, Christoph Bremer4, Thorsten Persigehl2 1Philips Research Europe, Hamburg, Germany; 2Department of Radiology, University of Muenster, Muenster, Germany; 3Department of Oncology, University of Muenster, Muenster, Germany; 4Department of Radiology, Franziskus Hospital, Muenster, Germany This work presents results from the first simultaneous steady-state blood volume and vessel size measurement in a human tumor outside the brain (phleomorphic sarcoma in the pubic bone). Images were free of artifacts, sequence timing allowed for appropriate coverage of the signal decays pre and post injection and the dR2*/dR2 values of the tumor were sufficiently high to generate robust physiologic maps, which appeared to be independent from contrast agent washout. Ian Tagge1, Ryan A. Priest2, Tomasz M. Beer3,4, Mark G. Garzotto5,6, William J. Woodward1, Wei Huang1, Charles S. Springer, Jr. 1,4, Xin Li1 1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States; 2Radiology, Oregon Health & Science University, Portland, OR, United States; 3Hematology/Oncology, Oregon Health & Science University, Portland, OR, United States; 4Knight Cancer Institute, Oregon Health & Science University, Portland, OR, United States; 5Urology, Oregon Health & Science University, Portland, OR, United States; 6Portland VA Medical Center, Portland, OR, United States Dynamic-contrast-enhanced magnetic resonance imaging (DCE-MRI) has shown promise in diagnostic medicine, particularly as applied to breast cancer screening. Pharmacokinetic parameter determination relies on arterial input function (AIF) validity. However, reliable AIFs are not easily obtained and often cannot be. Thus, it is often necessary to rely on an averaged, population AIF. The latter is also desired for data post processing simplification. Here, the standard model (SM) and first generation shutter-speed model (SSM) are used to assess the impact of a generic AIF on the pharmacokinetic parameter Ktrans (volume contrast reagent (CR) transfer constant) estimation in human prostate studies. Dustin K. Ragan1, Stephen Yenzen Lai2, James A. Bankson1 1Department of Imaging Physics, M. D. Anderson Cancer Center, Houston, TX, United States; 2Department of Head and Neck Surgery, M. D. Anderson Cancer Center, Houston, TX, United States Measurement of pharmacokinetic parameters in small animal models of cancer is a frequently-used tool in preclinical investigations of novel interventions. One source of uncertainty from these measurements arises from the challenges of quantifying the concentration time course of a contrast agent in blood. We have proposed performing this measurement in the heart, which allows reduced-artifact high temporal resolution sampling. A pilot study was performed in a thyroid tumor model comparing the inter-subject variation produced by cardiac sampling with conventional sampling in a local blood vessel, and found a large reduction in variation with the proposed approach. Perfusion Permeability Methodology Hall B Wednesday 13:30-15:30 Katherine L. Wright1, Nicole Seiberlich2, Stephen R. Yutzy1, Raymond F. Muzic1,2, Mark A. Griswold1,2, Vikas Gulani2 1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; 2Department of Radiology, Case Western Reserve University/University Hospitals, Cleveland, OH, United States In this work, Time resolved angiography WIth Stochastic Trajectories (TWIST) accelerated with parallel imaging, partial Fourier acquisition and view sharing, was used to obtain simultaneous angiography and dynamic contrast enhanced (DCE) perfusion measurements in muscle with a single contrast dose. Parameter optimization was performed to select combinations of undersampling schemes that provided the best temporal resolution while still limiting artifact power and error in perfusion measurements. The results were used to obtain MRA and perfusion exams on volunteer lower extremities during rest and exercise, demonstrating the ability of the technique to measure physiological perfusion changes. 2741. W. CBF But Not QOEF Is Affected by HIV Using QBOLD Withdrawn by Author Chia-Ming Shih1,2, Chien-Yuan Lin2, Chih-Yuan Chen2, Ta-Wei Chou2, Sui-Shan Lin2, Cheng-Hung Chou2, Yen-Yu Shih2, Jyh- Horng Chen1, Chen Chang2 1Institute of Biomedical Electronics and Bioinformatics, National Taiwan Unversity, Taipei, Taiwan; 2Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan Two different contrast agents with different approaches were needed for assessing the vascular permeability and structure including vessel size and vessel density. In the present study, First-Pass Function/Structure MR Imaging (First Pass F/S MRI) technique was proposed to simultaneously evaluate vascular function and structure. The proposed technique can reduce scan time and assess the correlation between functional and structural changes in brain tumor. Septian Hartono1,2, Choon Hua Thng1, Tong San Koh2, Puor Sherng Lee1, Fang Keang Lim1, Theng Boon Lee1, Helmut Rumpel3, Quan Sing Ng1 1National Cancer Centre Singapore, Singapore, Singapore; 2Nanyang Technological University, Singapore, Singapore; 3Singapore General Hospital, Singapore Hollow Fiber Bioreactors (HFBs), typically used for cell culture, mimicks well the human capillary system and thus is ideal to be used to validate the microcirculatory parameters obtained by tracer kinetic modeling. The aim of this study is to validate the permeability-surface area product (PS) obtained by tracer kinetic models with DCE-MRI in a HFB. Linear relationship was found between PS derived from the tracer kinetic models and pore size area of the HFBs. 2744. Measurement of Intracellular Water Preexchange Lifetime in Perfused Brains on Beads System Qingqing Ye1, William M. Spees2, Jim E. Huettner3, Joseph J. Ackerman1,2, Jeffrey J. Neil2,4 1Department of Chemistry, Washington University in St. Louis, St. Louis, MO, United States; 2Department of Radiology, Washington University in St. Louis, St. Louis, MO, United States; 3Department of Cell Biology and Physiology, Washington University in St. Louis, St. Louis, MO, United States; 4Department of Neurology, Washington University in St. Louis, St. Louis, MO, United States Preexchange lifetimes of intracellular water (τ in) are of fundamental significance to many experimental and theoretical studies, especially for modeling water behavior in tissue. Many methodologies have been developed to obtain this value for various cell types. Herein, we employed the method of perfusion of microbead-adherent cells, which allowed τ in measurement by highly effective suppression of the extracellular water MR signal and thus selective and direct observation of the intracellular water MR signals. Histologic evaluation confirmed that neurons and astrocytes grown on microbeads maintain key morphologic features. We found that τ ins for neurons and astrocytes are similar. 2745. Quantitative Dynamic 19F MRI Oximetry in a Phantom Simulating Hypoxia Steven H. Baete1,2, Yves De Deene1,2 1Laboratory for Quantitative Nuclear Magnetic Resonance in Medicine and Biology, ECNURAD, Ghent University, Ghent, Belgium; 2MEDISIP-IBBT, Ghent University, Ghent, Belgium Tumor hypoxia is well known to reduce cancer treatment efficacy. Fluor-19 MRI oximetry can be used to map oxygen concentrations in hypoxic tissue. In this study a reproducible phantom which mimics oxygen consuming tissue is used for quantitative dynamic fluor-19 MRI oximetry. The phantom consists of a hemodialysis filter of which the outer compartment is filled with a gelatin matrix containing viable yeast cells and perfluorocarbon vesicles which simulate the absorption of perfluorocarbons from intravenous emulsions in tissue. The phantom can be used for hypoxia simulations and for validating computational biophysical models of hypoxia, as measured with fluor-19 MRI oximetry. Karolien Jaspers1,2, Tim Leiner1,2, Petra Dijkstra3, Marlies Oostendorp1,2, Jolanda MCG van Golde4, Mark J. Post1,5, Walter H. Backes1,2 1Cardiovascular Research Insitute Maastricht, Maastricht, Netherlands; 2Radiology, Maastricht University Medical Centre, Maastricht, Netherlands; 3Central Animal Facilities, Maastricht University, Maastricht, Netherlands; 4Internal Medicine, Maastricht University Medical Centre, Maastricht, Netherlands; 5Physiology, Maastricht University, Maastricht, Netherlands Adequate introduction of therapeutic neovascularization in patients with peripheral arterial disease requires functional monitoring of vascular responses. The potential of the medium-sized contrast agent Gadomer for detecting (patho-) physiological perfusion differences with DCE-MRI was tested in a rabbit hind limb ischemia model. The lower extravasation rate of Gadomer requires a pharmacokinetic model that includes the blood plasma fraction vp rather than a model that accounts for reflux. Gadomer proved equally successful as Gd-DTPA in detecting flow differences between red (soleus) and white (tibialis) muscle, and between ischemic and normal soleus muscle tissue, while facilitating better image quality. Alexander Yowei Sheu1, Dingxin Wang1, Johnathan Chung2, Robert K. Ryu2, Reed A. Omary1,3, Debiao Li1, Andrew C. Larson1,3 1Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States; 2Department of Radiology, Northwestern University, Chicago, IL, United States; 3Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, United States Quantitative DCE-MRI can be used to measure pharmacokinetic parameters (Ktrans, ve, and vp) that indicate tumor angiogenesis and perfusion. The purpose of this study was to develop an innovative hybrid reference tissue calibrated dual-bolus 3D quantitative DCE-MRI method. Tissue contrast enhancement was quantified using 3D GRE DCE-MRI during first-bolus, AIF was monitored using 2D SR GRE DCE-MRI during second-bolus, and reference tissue (back muscle) was used to provide the final calibration. Our results support the use of quantitative DCE-MRI to differentiate hypervascular tumor tissue from the necrotic core, providing valuable diagnostic information about the stage and segmentation of a tumor. 2748. Phase Contrast Velocity Imaging Using Compressed Sensing Daniel J. Holland1, Dmitry M. Malioutov2, Andrew Blake2, Lynn F. Gladden1, Andrew J. Sederman1 1Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom; 2Microsoft Research Cambridge, Cambridge, United Kingdom This work describes a method for accelerating the acquisition of phase-encoded velocity images using compressed sensing. Results are shown for both experimental and simulated measurements of liquid and gas flow through a model porous material. Using this approach, acceleration factors for Cartesian data of between 2 and 5 are achieved with minimal reconstruction error. By combining this reconstruction algorithm with a variable density spiral acquisition, a full order of magnitude decrease in imaging time is achieved. This approach is applicable to MR angiography and perfusion studies in clinical MRI and to other phase imaging techniques. 2749. Intravoxel Incoherent Motion (IVIM) Imaging at Different Field Strengths What Is Feasible ? Anna Rydhög1, Matthias J. P. van Osch2, Markus Nilsson1, Jimmy Lätt3, Freddy Ståhlberg1,4, Ronnie Wirestam1, Linda Knutsson1 1Department of Medical Radiation Physics, Lund University, Lund, Sweden; 2Department of Radiology, LUMC, Leiden, Netherlands; 3Department of Image and function, University Hospital Lund, Lund, Sweden; 4Department of Diagnostic Radiology, Lund University, Lund, Sweden Intravoxel Incoherent Motion (IVIM) is a non-invasive method which has the potential to quantify perfusion parameters such as CBV and CBF from signal-versus-b data. Simulations was performed usinga synthetic voxel consisting of four different compartments (tissue, CSF, arterial and venous blood ) for comparison of the expected signal curves at three field strength (1.5, 3 and 7 T). Confirmation of the simulated results was obtained from in vivo measurements on a volunteer. We conclude that for higher field strengths the relative contribution from venous blood decreases suggesting that IVIM at 7 T would primarily reflect arterial blood volume. 2750. The Detection of Tumor Sub-Regions Based on T1 and ADC Clustering Caleb Roberts1,2, Chris Rose1,2, Josephine H. Naish1,2, Yvonne Watson1,2, Sue Cheung1,2, Gio A. Buonaccorsi1,2, Gordon C. Jayson3, John C. Waterton, 2,4, Jean Tessier4, Geoff J. Parker1,2 1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, The University of Manchester, Manchester, United Kingdom; 2The University of Manchester Biomedical Imaging Institute, The University of Manchester, Manchester, United Kingdom; 3Cancer Research UK Dept Medical Oncology, Christie Hospital and University of Manchester, Manchester, United Kingdom; 4AstraZeneca, Alderley Park, Macclesfield, Cheshire, United Kingdom Tracer kinetic model-based analyses of dynamic contrast-enhanced (DCE)-MRI data typically report summary statistics that treat tumors as being homogeneous. However, since anti-angiogenic therapies often preferentially affect certain parts of heterogeneous tumors there is interest in the development of methods to provide insight into regional changes. We present a method that uses k-means clustering of T1 and the apparent water diffusion coefficient (ADC) measured in a group of ovarian tumors to sub-divide tumors into distinct regions and demonstrate that differences in tracer kinetic parameters exist between these regions and the overall tumor median statistic. Olivier Maciej Girard1, Paul O. Scheibe2, David R. Vera1, Robert F. Mattrey1 1Department of Radiology , University of California, San Diego, CA, United States; 2Ixzar, Inc., Arroyo Grande, CA, United States Dynamic Contrast Enhanced (DCE) MRI is a promising tool to investigate microvascular tissue properties. Although it has been applied in various clinical studies its accuracy still remains subject to debate since numerous errors may bias the pharmacokinetic (PK) parameter estimates. Here we propose to study the propagation of measurement noise and flip angle (FA) uncertainty up to the PK parameter estimates using a MonteCarlo simulation. Our results show that in the high FA regime, a high FA uncertainty leads to a much lower bias in the PK parameter estimates while keeping the standard error due to noise close to its minimum. Lucy Elizabeth Kershaw1, Hai-Ling Margaret Cheng1,2 1The Research Institute and Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Department of Medical Biophysics, The University of Toronto, Toronto, Ontario, Canada This simulation study investigated parameter accuracy for the AATH model, which allows separate measurements of flow and permeability. The influence of three key factors was assessed: temporal resolution, signal to noise ratio and error in the AIF peak height measurement. Results showed that a high temporal resolution is the most critical factor in ensuring parameter accuracy but this requirement can be relaxed if larger biases can be permitted and Tc need not be accurately measured. An error of 10 % in the measurement of the AIF peak height resulted in an error of at most 10 % in each parameter. 2753. A General Dual-Bolus Approach for High Resolution Quantitative DCE-MRI Lucy Elizabeth Kershaw1, Marine Beaumont1, Hai-Ling Margaret Cheng1,2 1The Research Institute and Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Department of Medical Biophysics, The University of Toronto, Toronto, Ontario, Canada This study presents a dual-bolus technique to measure the arterial input function (AIF) for DCE-MRI. A low-dose prebolus was used to estimate the AIF for a tissue uptake curve measured from a second high-dose injection. AIFs were measured in the rabbit aorta using a high temporal resolution TRICKS acquisition. The scaled prebolus AIF was shown to match the main bolus AIF closely. Measurement of the AIF in a separate acquisition allows the tissue of interest to be imaged at high spatial resolution in a DCE-MRI experiment. 2754. Scope and Interpretation of the Modified Tofts Model Steven Sourbron1 1Ludwig-Maximilian-University Munich, Munich, Bavaria, Germany We present a theoretical analysis which shows that the modified Tofts model only applies to tissues that are weakly vascularized and permeability-limited. In other regimes, a model of exactly the same form applies, but the parameter typically interpreted as plasma volume has a mixed interpretation. Hence, if a modified Tofts model is found to describe the data well, none of the physical parameters are measureable without further assumptions on the state of the tissue. These ambiguities can only be resolved by sampling the data fast and precise enough, so that the complete two-compartment exchange model can be fitted. Hai-Ling Margaret Cheng1,2 1Research Institute & Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada; 2Medical Biophysics, University of Toronto, Toronto, Ontario, Canada Non-model DCE-MRI parameters such as the initial area under the uptake curve (IAUC) do not require arterial input function (AIF) measurement or model-fitting, and can hence be more robust than pharmacokinetic modeling. However, the IAUC is intractably correlated with biological parameters such as the transfer constant Ktrans and interstitial space ve. Herein, a modified IAUC (mIAUC) method is presented. The mIAUC parameters are strongly correlated with true Ktrans and ve, and are outperformed by pharmacokinetic parameters only when a rapidly sampled AIF is used. The proposed mIAUC method retains advantages of non-model DCE-MRI while providing stronger correlation with underlying physiology. Cancer: Cells Biopsies & Biofluids Hall B Thursday 13:30-15:30 Maria Falck Miniotis1, Thomas R. Eykyn1, Paul Workman2, Martin O. Leach1, Mounia Beloueche-Babari1 1CRUK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research & The Royal Marsden Hospital, Sutton, Surrey, United Kingdom; 2CRUK Centre for Cancer Therapeutics, The Institute of Cancer Research & The Royal Marsden Hospital, Sutton, Surrey, United Kingdom Deregulated RAS-BRAF-MEK1/2-ERK1/2 signalling is frequently observed in cancer and considerable effort is focused towards developing MEK1/2-targeted therapy. We previously reported that MEK1/2 inhibition causes a reduction in 1H MRS-detectable lactate in human cancer cells. Here we analyse the time-course of the response and investigate the mechanism behind this effect by assessing glucose uptake and lactate dehydrogenase (LDH) activity. We demonstrate that MEK1/2 inhibition leads to decreased lactate production through down-regulation of both glucose uptake and LDH activity. These results show lactate as a potential non-invasive MRS biomarker of response to MEK1/2-targeted therapeutics. 2757. Metabolic Consequences of Perifosine Treatment Judy S. Hwang1, Sabrina M. Ronen1 1Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States Perifosine is a novel anticancer alkylphospholipid that is in clinical trials for treatment of cancer. This study investigates the changes in choline metabolism of MCF-7 human breast cancer cells modulated by perifosine treatment. Cells were incubated with 13C labeled choline and 1H, 13C, and 31P MR spectra of cell extracts were recorded. The overall inhibition of phosphatidylcholine synthesis via the Kennedy pathway was observed upon treatment. The accumulation of perifosine was also detected in the cell membrane. The observed changes in choline metabolism upon perifosine treatment could reflect its mechanism of action or its effect on PI3K signaling. Nada M.S. Al-Saffar1, Laura L. Jackson1, Swee Sharp2, Loreta Rodrigues3, John R. Griffiths3, Paul Workman2, Martin O. Leach1 1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom; 2CR-UK Centre for Cancer Therapeutics, Institute of Cancer Research, Sutton, Surrey, United Kingdom; 3CR-UK Cambridge Research Institute, Cambridge, United Kingdom 17-AAG is a novel anticancer drug that inhibits heat shock protein 90 (HSP90) leading to combinatorial degradation of many oncogenic client proteins including NEU/HER2 and its downstream proteins, which have key roles in cell growth and survival. NEU/HER2 is overexpressed in 25% of human breast cancers. In this study, we have used 1H and 31P-MRS to establish biomarkers for HSP90 inhibition in cells isolated from a NEU/HER2-driven mammary carcinoma Oncomouse®. We report a 2-fold increase in choline-containing metabolites which was associated with a decrease in NEU/HER2 expression. Hence these MRS changes could serve as biomarkers for HSP90 inhibition in cells/tumors driven by NEU/HER2. Hitoshi Kubo1, Masafumi Harada1, Takamasa Abe2, Hiroshi Maezawa3, Hiromu Nishitani4 1Department of Medical Imaging, University of Tokushima, Tokushima, Japan; 2SBD/MR Division, Oxford Instruments KK., Tokyo, Japan; 3Department of Radiation Physics, Engineering and Biology, University of Tokushima, Tokushima, Japan; 4Department of Radiology, University of Tokushima, Tokushima, Japan The early metabolic response of pyruvate and lactate induced by 5-fluorouracil (5FU) on mouse mammary cancer cells under normal and fasting conditions was evaluated by NMR measurement using hyperpolarized 1-13C-pyruvate and absorption spectroscopy. This study measured four combinations of nutritional status and treatment with 5FU. The rate constant of pyruvate-lactate metabolism was changed by the nutritional conditions without and with 5FU treatment. The results suggested that this technique allows the detection of the early metabolic response induced by an anticancer agent. Siver Andreas Moestue1, Vickie Yi Zhang2, Else Marie Huuse1, Beathe Sitter1, Gunhild Mari Męlandsmo3, Olav Engebråten3, Ingrid Susann Gribbestad1 1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway; 2Department of Radiology and Biomedical Imaging, UCSF, San Francisco, United States; 3Department of Tumor Biology, Institute for Cancer Research, Oslo, Norway An estrogen-dependent luminal-like breast cancer xenograft model was used to study choline metabolites after endocrine therapy using HR MAS MRS. The data suggested that choline metabolite concentrations do not change following endocrine therapy wheras taurine and lactate do change. 2761. Myc Regulates a Transcriptional Program That Stimulates Glutaminolysis David R. Wise1, Anthony Mancuso, Ralph Deberardinis2, Sayed Nabil, Xiao-Yong Zhang3, Harla K. Pfeiffer3, Ilana Nissim4, Evgueni Daikhind4, Marc Yudkoff4, Steven B. McMahon3, Craig B. Thompson 1Cancer Biology, University of Pennsylvania, Philadelphia, PA, United States; 2University of Texas South Western Medical Center; 3Thomas Jefferson Medical College; 4Children's Hospital of Philadelphia High levels of both glucose and glutamine consumption are required for rapid proliferation of most cancer cells. In this work, the role of myc in regulating the transcriptional control of glutaminolysis was examined. Two different models were used: immortalized mouse embryo fibroblasts (MEF) with inducible myc activity and human glioma cells with naturally high myc levels that were knocked down with short-hairpin RNA. Elevated myc activity was associated with increased glutamine transport, glutaminase activity and lactate dehydrogenase activity as demonstrated by PCR. It was also associated with increased overall glutimolytic flux as evidenced by 13C NMR. 2762. MR Determind Metabolites May Serve as Prognostic Factors in Breast Cancer Tone Frost Bathen1, Beathe Sitter1, Guro F. Giskeųdegård1, Lutgarde Buydens2, Geert Postma2, Hans Fjųsne3, Steinar Lundgren1,4, Ingrid S. Gribbestad1 1Dept. of Circulation and Medical Imaging, NTNU, Trondheim, Norway; 2Dept. of Analytical Chemistry, Radboud University Nijmegen, Nijmegen, Netherlands; 3Dept. of Surgery, St. Olavs University Hospital, Trondheim, Norway; 4Dept. of Oncology, St.Olavs University Hospital, Trondheim, Norway The purpose of the current study was to define new prognostic factors for breast cancer based on HR MAS MRS. Proton MR spin echo spectra were acquired from excised breast cancer tissue. 5-years follow-up data were available for all included patients. The spectra were analysed with PCA. Using ROC and Kaplan-Meyer survival analysis of score values, two groups with significant different cumulative survival were defined. Higher levels of glycerophosphocholine, betaine and creatine, and lower levels of lactate and glycine were associated to good prognosis. A combination of MR determined metabolites may serve as an additional prognostic factor in breast cancer. 2763. 31P NMR of Phospholipid Metabolites in Prostate Cancer and Benign Prostatic Hyperplasia Richard A. Komoroski1, John C. Holder2, Alex A. Pappas2, Alex E. Finkbeiner2, Sadhna Verma1 1University of Cincinnati, Cincinnati, OH, United States; 2University of Arkansas for Medical Sciences, Little Rock, AR, United States Although 31P NMR is an excellent method for probing the phospholipid (PL) metabolites in prostate cancer, it has been little used recently. We report an in vitro 31P NMR comparison of prostate cancer and benign prostatic hyperplasia (BPH), focusing on the levels of major PL metabolites. Unlike phosphocholine (pc) and glycerophosphocholine (gpc), phosphoethanolamine (pe) and glycerophosphoethanolamine (gpe) (and their ratio) were significantly different between cancer and BPH. The levels of pe and gpe relative to those of pc and gpc are consistent with the former being major contributors to the total choline resonance observed by 1H MRS in vivo. Dominik Zietkowski1, Robert L. Davidson1, Thomas R. Eykyn1, Sonali S. De Silva1, Nandita M. deSouza1, Geoffrey S. Payne1 1CR-UK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research, Sutton, Surrey, United Kingdom An optimised diffusion-weighted stimulated echo sequence with bipolar gradients attenuated low molecular weight metabolites in cervical cancer tissue samples giving improved visibility and characterisation of mobile lipid resonances (MLR). Linear discriminant analysis (LDA) of MLR peaks almost completely separated cervical biopsies containing cancer from those that did not, reflecting underlying differences in MLR composition. Generated Receiver Operating Characteristic (ROC) curves and calculated area under the curve (0.962) validated high sensitivity and specificity of the technique. 2765. Choline Metabolite Ratios from NMR as Markers of Human Breast Cancer Mary C. Mahoney1, Jing Huei Lee2, Wen Jang Chu2, John M. Pearce2, Kim M. Cecil3, Stephen M. Strakowski2, Richard A. Komoroski2 1Radiology, University of Cincinnati, Cincinnati, OH, United States; 2Center for Imaging Research, University of Cincinnati, Cincinnati, OH, United States; 3Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States In vivo 1H MRS of breast cancer lesions can detect a signal assigned to total choline (tCho), which arises from a variety of choline-containing metabolites. The contribution of each metabolite to the increased tCho peak in vivo is not known. Here we report in vitro 1H NMR spectroscopy results on fine-needle aspirate (FNA) biopsies of lesions from breast cancer patients, several of whom were also studied by in vivo MRS. Phosphocholine was usually the major metabolite, whereas the contribution of glycerophosphocholine varied substantially, and that of Cho was always minor. Egidio Iorio1, Marina Bagnoli2, Alessandro Ricci1, Maria Elena Pisanu1, Kristine Glunde3, Giancarlo Castellano2, Elisa Venturini4, Zaver M Bhujwalla3, Delia Mezzanzanica2, Silvana Canevari2, Franca Podo1 1Istituto Superiore di Sanitą, Roma, Italy; 2Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy; 3Johns Hopkins University School of Medicine, Baltimore, MD, United States; 4Cogentech-Consortium for Genomic Technologies, Milano, Italy Altered phosphatidylcholine (PC) metabolism in epithelial ovarian cancer (EOC) can provide choline-based imaging approaches as powerful tools to improve diagnosis and identify new therapeutic targets. Measurements are reported on protein expression and enzyme activation of choline kinase (ChoK) and PC-specific phospholipase C (PC-plc) in EOC cell lines compared with non tumoral counterparts. The role of Chok and PC-plc in the intracellular accumulation of PCho in EOC cells was investigated by RNA silencing and pharmacological inhibition respectively. Analyses are also reported on ChoKį mRNA expression and on ChoK and PC-plc protein expression in a set of surgical specimens from EOC patients. Noriko Mori1, Flonne Wides2, Tomoyo Takagi2, Kristine Glunde2, Zaver M. Bhujwalla2 1JHU ICMIC Program, The Russell H. Morgan Department of Radiology and Radiological Science, , The Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2JHU ICMIC Program, The Russell H. Morgan Department of Radiology and Radiological Science,, The Johns Hopkins University School of Medicine, Baltimore, MD, United States Elevated lipogenesis is a characteristic feature of cancer. Fatty acid synthase overexpression has been found in many human cancers. Both tumor cells in culture and solid tumor models are essential tools to study cancer biology. To understand the differences in lipid components between tumor cells in culture and solid tumors, we compared fatty acid and phosphatidylcholine levels with 1H MRS of lipid-soluble cell or tumor extracts derived from prostate and breast cancer cell lines. Significantly different patterns of fatty acid levels between cells in culture and in tumors, demonstrate the importance of the tumor microenvironment in lipid metabolism. 2768. Metabolic Profile of Lipid Extracts Obtained by Astrocytic Brain Tumors Frauke Nehen1, Wieland Willker1, Laura Columbano2, Rudolf Fahlbusch2, Dieter Leibfritz1 1Institute of Organic Chemistry, University of Bremen, Bremen, Germany; 2International Neuroscience Institute Hannover, Hannover, Germany Lipophilic tissue extracts of astrocytic brain tumors were analyzed by 1H-NMR spectroscopy. Tumor core, tumor margin and reference tissue differ significantly with respect to their content of galactosyl cerebrosides and one unknown metabolite. Lipid separation with solid phase extraction of eight lipid extracts, enrichment by combining fractions in which the unknown metabolite was observed and analysis by various 2D-NMR methods revealed that the unknown metabolite is an isoprene derivative. 2769. Peak Alignment of MR Spectra Guro Fannelųb Giskeųdegård1, Tom Bloemberg2, Lutgarde Buydens2, Geert Postma2, Ingrid Susanne Gribbestad1, Tone Frost Bathen1 1Dept. of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 2Dept. of Analytical Chemistry, Radboud University Nijmegen, Nijmegen, Netherlands Correction of misaligned peaks is an important part of multivariate preprocessing of MR spectra. In this study, three different peak alignment algorithms were tested on HR MAS MRS data from breast cancer tissue. The datasets were used to predict the prognostic factor ER status, which is shown to be related to metabolic profile. Correlation optimized warping (COW) and peak alignment by genetic algorithm (PAGA) resulted in greatly improved PLS-DA classification of ER status compared to unaligned data. Parametric time warping (PTW) did not improve the classification error, indicating that PTW may not be as suitable for metabolomic MR data. Christopher S. Ward1, Sabrina M. Ronen1 1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States CTP:choline-phosphate cytidylyltransferase (CCT) is the enzyme responsible for catalyzing the addition of CTP to phosphocholine to form CDP-choline, which is generally accepted to be the rate-limiting reaction in the formation of phosphatidylcholine. This study introduces a dynamic 31P MR-based means to measure the kinetics of the cytidylyltransferase-catalyzed reaction. The results suggest the potential of this technique to quantitatively assess modulations in CCT activity. 2771. Metabolic Changes Associated with HPV Infection in Cancer Cells Observed with 1H MRS Dominik Zietkowski1, Geoffrey S. Payne1, Nandita M. deSouza1 1CR-UK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research, Sutton, Surrey, United Kingdom This study investigates the metabolic effects of HPV infection and tests whether 1H MRS can detect these in a model consisting of isogenic HPV-16 E6 transfected derivatives of A2780 ovarian cell line (E6 is the key cancer-causing HPV protein). It was possible to observe in the HPV-E6 transfects higher cholines, lower lactate, glycine, lipids and their (poly-) unsaturation. These changes seem to be related to changes in E6 transfects proliferation. Similar changes may also apply to HPV infection in cervix and documenting these may provide insights to understand the metabolic field effect observed around cervical tumor and into viral oncogenesis. 2772. Detection of Apoptotic Cell Death in Vitro Using Quantitative Magnetization Transfer Colleen Bailey1,2, Kimberly L. Desmond1,2, Gregory J. Czarnota1,2, Greg J. Stanisz1,2 1Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 2University of Toronto, Toronto, ON, Canada Acute myeloid leukemia cells were treated with cisplatin to induce apoptosis and spun into a cell sample for imaging. Magnetization transfer scans were performed at 427 and 243 Hz peak power, for sixteen offset frequencies logarithmically spaced from 0.12 to 200 kHz. The magnetization transfer ratio at 2320 Hz showed a statistically significant increase from 24.8% in control cells to 28.0% thirty-six hours after cisplatin treatment and 30.3% forty-eight hours after cisplatin treatment, preceding T1 changes. Quantitative fitting showed an increase macromolecular/free water proton exchange and a decrease in T2B, which characterizes the width of the macromolecular lineshape. Animal Models of Cancer Hall B Monday 14:00-16:00 2773. Hyperpolarized 13C Biomarkers of Androgen Independent Prostate Cancer Paniz Vafaei1, Robert Bok1, Lynn DeLosSantos, Vicki Zhang, Phillip Guan, Dan Vigneron, John Kurhanewicz 1Radiology, University of California, San Francisco, San Francisco, CA, United States Androgen independence of prostate cancer is an important clinical status to identify, but no well-defined biomarkers for this state exist. In this study we used fast 13C-MRSI after injection of hyperpolarized [1-13C] pyruvate and pathological and biochemical analysis of the tumor to determine hyperpolarized (HP) biomarkers of androgen dependent and androgen independent prostate cancer. Androgen independent phenotype had a significantly higher HP lactate/noise, Total Hyperpolarized Carbon, HP lactate/pyruvate, and LDH activity relative to the androgen dependent phenotype. 2774. Multi-Parametric Characterization of an Experimental Model of Cancer Cachexia Marie-France Penet1, Sridhar Nimmagadda1, Mayur Gadiya1, Balaji Krishnamachary1, Martin G. Pomper1, Zaver M. Bhujwalla1 1JHU ICMIC Program, Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States Cachexia is a life-threatening syndrome of progressive weight loss that occurs with a high frequency in several cancers. A better in vivo characterization of cachectic tumors is important to identify new targets and improve treatment to arrest or reverse this condition. Here we have characterized differences in vascular properties, quantified by 1H magnetic resonance imaging of the intravascular agent albumin-GdDTPA, between cachectic and non-cachectic tumors. We also performed 18F-deoxyglucose PET imaging to study the glycolytic activity of those tumors. We found significantly less permeable vasculature and increased glycolytic activity in the cachectic tumors compared to the non-cachectic ones. Boris Odintsov1, Vadim Aleksandrovich Atsarkin2, Viktor Demidov3, Andrey Kaul4, Mariya Popova4, Carolina Soto5, Edward Roy6 1Biomedical Imaging Center, University of Illinois , Urbana-Champaign, IL, United States; 2IRE RAN, Moscow, Russian Federation; 3IRE RAN, Russian Federation; 4Moscow University, Russian Federation; 5UIUC, IL, United States; 6University of Illinois, Urbana-Champaign, IL, United States New nanomaterials recently synthesized in our group are lanthanum manganite doped with silver ions. The unique feature of the doped manganites is the possibility to control their Curie temperature in the range of tumor hyperthermia interest (41-43oC). At its Curie temperature, a ferromagnetic particle loses its magnetic properties; this metal-insulator phase transition is tunable and reversible. New ferromagnetic particles adopt the superparamagnetic behavior and are comparable to iron oxide as an MRI contrast agents. The goal of this presentation is to introduce newly synthesized nanomaterials and create a new platform for highly controllable hyperthermia cancer therapy and imaging. 2776. High Resolution MRI of Tumors in the Smo/Smo Mouse Medulloblastoma Model Donghoon Lee1, Stacey Hansen2, Richard Ellenbogen1, Miqin Zhang1, James Olson2 1University of Washington, Seattle, WA, United States; 2Fred Hutchinson Cancer Research Center, Seattle, WA, United States This work describes MRI methods for diagnosis and staging of tumors in the Smo/Smo genetically engineered mouse model of medulloblastoma. High resolution MRI was performed to attain T2 weighted imaging to screen tumors, T1 weighted imaging to examine the blood brain barrier integrity, and diffusion weighted imaging to improve tumor delineation. Sub-millimeter sized tumors in mice as young as 2 months were imaged even though animals were asymptomatic by other criteria. MRI findings were well correlated with histopathology. Thus, high resolution MR imaging is an excellent way to detect and stage tumors in mouse medulloblastoma models. 2777. Fast, High-Resolution, 3-Dimensional Imaging of the Mouse Prostate with BSSFP Christiane L. Mallett1,2, Paula J. Foster1,2 1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada; 2Medical Biophysics, The University of Western Ontario, London, Ontario, Canada Purpose: To obtain high-quality images of the mouse prostate for studies of prostate cancer. Methods: Mice were imaged with balanced steady state free precession (bSSFP), T1- and T2-weighted spin-echo sequences. Results: We obtained whole-body images at 200 micron resolution that included the prostate, popliteal and inguinal lymph nodes in ~25 mins. 2D T1- and T2-weighted SE sequences had inferior SNR per slice thickness and prostate-fat CNR relative to bSSFP. Conclusion: bSSFP gives fast, high resolution, 3D mouse prostate and body imaging with high SNR and CNR. This will be used in studies of prostate cancer and metastasis. 2778. MRI Characterisation of a Novel Transgenic Mouse Model of Neuroblastoma Yann Jamin1, Elizabeth Ruth Cullis2, Lynsey Vaughan2, Dow-Mu Koh1, Louis Chesler2, Simon P. Robinson1 1Cancer Research UK and EPSRC Cancer Imaging Center, The Institute of Cancer Research and Royal Marsden NHS Trust, Sutton, Surrey, United Kingdom; 2Section of Paediatric Oncology, The Institute of Cancer Research, Sutton, Surrey, United Kingdom This study characterises the novel transgenic murine TH-MYCN model of highrisk human neuroblastoma, the most common extracranial childhood solid tumour, with MRI, especially the anatomical presentation, the longitudinal development of the tumour in situ, and its established response to the chemotherapeutic agent cyclophosphamide in vivo. In addition, quantitative MRI parameters, and interrogation of the tumour vasculature by DCE-MRI, are also reported. We demonstrate that MRI screening would be a crucial asset in the development of novel MYCN-targeted therapeutics for neuroblastoma and would accelerate their clinical development by allowing simultaneous evaluation of preclinical MRI biomarkers of treatment response. Sungheon Kim1, Lindsey DeCarlo2, Gene Young Cho1, Jens H. Jensen1, Daniel K. Sodickson1, Linda Moy1, Silvia Formenti3, Robert J. Schneider2, Eric E. Sigmund1 1Center for Biomedical Imaging, Radiology, New York University, New York, NY, United States; 2Microbiology, New York University, New York, NY, United States; 3Radiation Oncology, New York University, New York, NY, United States Effective delivery of therapeutic drug is often impeded by physiological barriers including elevated interstitual fluid pressure (IFP). In this study, we investigated the feasibility of using Intra-Voxel-Incoherent-Motion (IVIM) diffusion weighted imaging (DWI) to measure tumor blood flow and the association of IVIM diffusion coefficients with IFP. From a study of 10 mice with 4T1 mouse mammary tumor model, strong correlations (R2 > 0.64) were observed between the elevated IFP (> 5 mmHg) and diffusion coefficients estimated using monoexponential as well as biexponential diffusion models. This result suggests a high potential of DWI parameters as surrogate markers for IFP. Prachi Pandit1,2, Samuel M. Johnston1,2, Yi Qi2, Jennifer Story3, Beth Hollister3, G A. Johnson1,2 1Biomedical Engineering, Duke University, Durham, NC, United States; 2Center for In Vivo Microscopy, Duke University, Durham, NC, United States; 3Piedmont Research Center, Morrisville, NC, United States In this work we present a longitudinal, multi-modality study to monitor the growth of liver metastases in mouse model of colon carcinoma. We have compared the relative merits of using high-field T2-weighting MRI and contrast-enhanced microCT as a preclinical cancer imaging technique in free-breathing mice. The advantages of microCT lie in the fast acquisition of high-resolution isotropic datasets. MRI, on the other hand has higher contrast resolution, and requires neither contrast injection nor radiation dose. Both techniques, ungated MRI and respiratory-gated MicroCT, perform well in the presence of motion, and are sufficiently fast and non-invasive to allow repeated scanning. 2781. Imaging of Tumor Angiogenesis in a Novel Skin Chamber Using MRI and Optical Imaging Tobias Bäuerle1, Clarissa Gillmann2, Reiner Umathum1, Margareta M. Müller3, Michal Neeman4, Wolfhard Semmler2, Michael Bock1 1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany, Germany; 2Medical Physics in Radiology, German Cancer Research Center , Heidelberg, Germany, Germany; 3Tumor- and Microenvironment, German Cancer Research Center, Heidelberg, Germany, Germany; 4Biological Regulations, The Weizmann Institute of Science, Rehovot, Israel Tumor angiogenesis in animal models is often visualized using optical imaging or MRI. In this work we present a subcutaneous skin chamber for simultaneous optical and MR imaging to study the tumor-induced growth of blood vessels in vivo. The fully MR-compatible chamber features an optical window, and can be combined with a dedicated external loop coil. Caroline Diepart1, Oussama Karroum, Julie Magat, Olivier Feron, Bénédicte Jordan, Bernard Gallez 1UCL, Brussels, Belgium As2O3 inhibits mitochondrial respiratory function in human leukemia cells. We hypothesized that As2O3 could also be an important modulator of tumor oxygenation by affecting the oxygen consumption of solid tumors. We observed an increase in tumor pO2 in two tumor models after arsenic treatment using oximetry techniques based on EPR and 19F NMR relaxometry. This effect was explained by a decrease in oxygen consumption of the tumors. Finally, the irradiation of tumors showed a regrowth delay that was significantly increased in arsenic-treated mice. As2O3 is an important modulator of pO2 by decreasing oxygen consumption and enhances the response of tumors to radiotherapy. Simon Walker-Samuel1, Matthew Orton1, Jessica K R Boult1, Simon P. Robinson1 1Cancer Research UK & EPSRC Cancer Imaging Centre, The Institute of Cancer Research, Sutton, Surrey, United Kingdom A method for improving ADC estimates using an adaptive Bayesian Markov random field analysis is described and evaluated using simulations and in vivo tumour models. Via the sharing of information between neighbouring pixels, the uncertainty and error in ADC estimates are significantly reduced by a factor of up to 80%. The approach also enables the segmentation of homogeneous tissue components and a novel measure of tissue (tumour) heterogeneity is described. Caroline Chung1, Warren Foltz1, Petra Wildgoose1, Kelly Burrell2, Patricia Lindsay1, Andrea Kassner3, David Jaffray1, Gelareh Zadeh4,5, Cynthia Menard1 1Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada; 2SickKids' Hospital, Toronto, Ontario, Canada; 3SickKids Hospital, Toronto, Onatario, Canada; 4Brain Tumour Research Centre, Toronto, Ontario, Canada; 5Toronto Western Hospital, Canada This study demonstrates feasibility of using multiparametric micro-MRI to overcome the challenges of intracranial mouse tumour models. Baseline T2w images were used to select mice with visible tumours and to stratify mice to treatment arms based on tumour size. Serial multiparametric MRI was used to measure tumour growth and vascular changes on DCE-MRI (iAUC60) with radiation (RT) and/or sunitinib (SU) anti-angiogenic treatment. Early rises in iAUC60 were noted following both RT and SU monotherapy, while the combination of RT and SU resulted in an early significant decrease in iAUC60. These early measured DCE-MRI changes show promise as useful early biomarkers for treatment response. 2785. A Multiple Coil Array Approach for Mouse Brain Tumor Imaging Lilia V. Ileva1, Marcelino Bernardo2,3, Diane Palmieri4, Patricia Steeg4, Joseph Kalen1, Peter Choyke2 1Small Animal Imaging Program, SAIC-Frederick, NCI-Frederick, Frederick, MD, United States; 2Molecular Imaging Program, NCI, NIH, Bethesda, MD, United States; 3Imaging Physics, SAIC-Frederick, NCI-Frederick, Frederick, MD, United States; 4Laboratory of Molecular Pharmacology, NCI, NIH, Bethesda, MD, United States Multiple mouse MRI is of critical importance in preclinical cancer research when longitudinal studies with multiple animals is required. This work presents a four-mouse brain imaging coil system and its application in the development of a breast cancer brain metastasis mouse model. The four-mouse SENSE array is integrated in a single platform with physiological support system. Six imaging sessions on 18 mice were performed weekly to monitor the initiation and progression of the brain metastases. The usage of the multiple mouse brain coil system significantly improved the efficiency of MRI studies involving serial imaging of multiple small animals. Maria Tunset Grinde1, Siver Andreas Moestue1, Ųystein Risa1, Olav Engebraaten2, Ingrid Susann Gribbestad1 1Department of Circulation and Medical Imaging, NTNU, Trondheim, Norway; 2Department of Tumor Biology, Cancer Research Institute, Oslo University Hospital, Oslo, Norway 13C HR MAS MR spectroscopy has been used to study two breast cancer xenograft models, representing a human luminal-like and a basal-like genetic profile. The models received a bolus injection of [1-13C]glucose and the conversion from glucose to lactate and alanine was observed 10 or 15 minutes after. The luminal-like model showed a significantly lower ratio of glucose/alanine and glucose/lactate compared to the basal-like model. This can be explained by a lower uptake of glucose and/or a higher rate of glucose metabolism towards alanine and lactate in the luminal-like compared to the basal-like model. 2787. DMSO as a Potential Contrast Agent for Brain Tumours Teresa Delgado-Goni1,2, Rui V. Simoes, 12, Milena Acosta, 12, Juana Martin-Sitjar1,2, Silvia Lope-Piedrafita, 2,3, Carles Arus1,2 1Bioquimica i Biologia Molecular, Universitat Autonoma of Barcelona, Cerdanyola del Valles, Barcelona, Spain; 2CIBER-BBN, Zaragoza, Spain; 3Servei de Ressonancia Magnetica Nuclear, Universitat Autonoma of Barcelona, Cerdanyola del Valles, Barcelona, Spain We describe here the application of Dimethyl Sulfoxide (DMSO) as a potential contrast agent for brain tumour imaging. DMSO crosses the blood-brain-barrier, but its differential wash-out kinetics produces a clear contrast enhancement in mouse brain glioblastoma compared to nearby/peritumoral brain parenchyma, measured by SV MRS and MRSI sequences. Andriy Babsky1, Shenghong Ju2, Beena George, Stacy Bennett, Mingsheng Huang, Hiremagalur N. Jayaram, Gordon McLennan, Navin Bansal 1Radiology, Indiana University, Indianapolis, IN, United States; 2Indiana University Implantation of N1S1 cells in the rat liver can be used as an intrahepatic hepatocellular carcinoma (HCC) model for pre-clinical study of transarterial therapy with the apoptotic agent benzamide riboside (BR). Water apparent diffusion coefficient (ADC) in HCC was higher than in nearby normal liver tissue. Intrahepatic infusion of BR was a semi-effective treatment of HCC in rats. BR therapy did not change the water ADC value, regardless of tumor sensitivity. A higher initial ADC level could be a promising sign for effective BR treatment, and in contrast, tumors with a lower initial ADC value are most likely to be resistant to BR-treatment. Else Marie Huuse1, Siver Andre Moestue1, Olav Engebråten2,3, Tone Frost Bathen1, Ingrid Susann Gribbestad1 1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 2Department of Tumor Biology, Institute for Cancer Research, Oslo, Norway; 3Oslo University Hospital , Oslo, Norway Molecular sub-classification of breast cancer based on gene expression pattern represents clinically distinct patient groups with different outcome. Two breast cancer xenograft models reflecting two of these groups: Basal like (ER-, poor prognosis) and luminal like (ER+, better prognosis), were characterized using DCE-MRI. Our results shows a significant higher Ktrans in basal like than in luminal like small tumors, however, this difference disappears for large tumors. Estradiol withdrawal had minor effect on growth and DCE-MRI derived parameters for the basal like tumors. The luminal like tumors ceased to grow and had a significant increase in Ktrans and ve . 2790. Comparative Analysis of Gd Vs Dy in DSC-MRI Studies of a High Grade Glioma Murine Model Rocķo Pérez-Carro1, Jesśs Pacheco-Torres1, Sebastiįn Cerdįn1, Pilar Lopez-Larrubia1 1Insituto de Investigaciones Biomedicas, CSIC/UAM, Madrid, Spain Gd(III) is the lanthanide ion more widely used as longitudinal relaxation enhancer due to its long electronic relaxation time. Stable Gd complexes are the T1 contrast agents more used for MRI studies. Other paramagnetic lanthanides as Dy(III) are also employed as contrast agents in dynamic susceptibility contrast MRI. We used both Gd and Dy containing chelates in perfusion studies to yield parametric maps (CBF, CBV and MTT) in a high grade glioma rat model. The goal is to establish an optimal method to delimit and characterize brain regions in the murine model to test the effectiveness of antiangiogenic therapies. Norbert W. Lutz1, Johanna Chiche2, Yann Le Fur1, Christophe Vilmen1, Frédéric Frassineti3, Laurent Daniel3, Jacques Pouysségur2, Patrick J. Cozzone1 1CRMBM UMR 6612 CNRS, Aix-Marseille University, Medical School, Marseille, PACA, France; 2Institute of Developmental Biology and Cancer Research CNRS UMR 6543, Centre A. Lacassagne, Nice; 3Inserm UMR 911-CRO2, Aix-Marseille University, Medical School The current use of angiogenesis inhibitors for cancer treatment requires further modifications of the hypoxic tumor microenvironment to achieve complete tumor regression. To contribute to the development of a new treatment strategy, we investigated effects of modulations of multiple mechanisms of glycolytic activity and pH regulation on intracellular and extracellular pH (pHi, pHe) by 31P NMR spectroscopy of tumor xenografts in nude mice. Three ras-transformed fibroblast variants were compared: wild-type CCL39, and mutants defective in either glycolysis or respiration. Compared to CCL39, pHi was increased in either mutant, and pHe was less heterogenous due to a reduction of low-pHe regions. Harald Kramer1, Val M. Runge2, L Gill Naul2, Alan T. Loynachan3, Maximilian F. Reiser1, Bernd J. Wintersperger1 1Department of Clinical Radiology, University Hospital Munich, Munich, Germany; 2Scott and White Memorial Hospital, TX, United States; 3University of Kentucky, KY, United States The detection of a link between the application of Gd contrast agents highlights the need for dedicated application protocols. The purpose of the study was to evaluate the efficacy of single dose gadobutrol compared to a substantially higher dose gadoterate meglumine in a tumor model at 1.5T and 3.0T. All animals were implanted Glioma cells using an implanted plastic brain cannula. After 7 days brain MR exams were performed whether with gadobutrol or gadoterate meglumine with a 24h interval. After the second MRI brains harvested for histopathologic assessment. Data were evaluated regarding SNR, CNR and lesion enhancement (LE). Heling Zhou1, Amyn A. Habib1, Ralph P. Mason1, Dawen Zhao1 1Radiology, UT Southwestern Medical Center, Dallas, TX, United States Glioma is a lethal cancer. It is imperative to non-invasively evaluate intracranial tumor microenvironment. We applied multiple MRI approaches to evaluate tumor microenvironment in orthotopic gliomas in a mouse model. An interleaved T2*-weighted and T1-weighted sequence, sensitive to both blood and tissue oxygen tension, was applied to assess tumor oxygenation. Our results showed significantly increased signal intensity in intracranial tumors with oxygen inhalation. Dynamic susceptibility contrast MRI was used to evaluate vascular perfusion and correlate with change in oxygenation. Our study suggests the integrated MRI approaches will be useful to evaluate interplay of tumor oxygenation and hemodynamics. Breast Cancer: Spectroscopy & More Hall B Tuesday 13:30-15:30 Sonia P. Li1, N J. Taylor2, J J. Stirling2, Mei-Lin W. Ah-See1, Mark J. Beresford1, David J. Collins3, James A. d'Arcy3, Andreas Makris1, Anwar R. Padhani2 1Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, United Kingdom; 2Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, United Kingdom; 3CR-UK Clinical MR Research Group, Royal Marsden Hospital, Sutton, Surrey, SM2 5PT, United Kingdom R2* has potential to provide information about tumour oxygenation but is underexplored in breast cancer. Here, primary carcinomas were imaged with multiparametric MRI before and after 2 cycles of neoadjuvant chemotherapy. Correlations between R2* and kinetic parameters were investigated. R2* as a predictor of pathological benefit was compared with DCE/DSC-MRI parameters. Significant inverse correlations between R2* and blood flow/volume in untreated cancers confirm that R2* reflects blood oxygenation; however this relationship disappears after treatment. Increases in R2* in responders suggest that cancers become more hypoxic with successful treatment. R2* was a relatively poor response predictor compared with some DCE and DSC-MRI parameters. Dennis WJ Klomp1, Bart van de Bank1, Alexander Raaijmakers2, Mies Korteweg1, Cecilia Possanzini3, Vincent Boer1, Nico van de Berg2, Maurice van de Bosch1, Peter Luijten1 1Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands; 3Philips Health Care In this work we demonstrate the ability to detect multiple phospholipid metabolites in vivo in the human female breast using focused field coils at 7T. For the first time ever, these signals are detected locally with a spatial resolution of 10 ml. The signals are detected from breast cancer tissue, which has a high concentration of choline levels and even from healthy, glandular breast tissue as well, which has low levels of total choline (i.e. < 0.5 mM). 2796. A Total Choline Quantification Method for Water- And Lipid-Suppressed Breast Spectra at 3T Chenguang Zhao1, Patrick Bolan2, Melanie Royce3, Anne Marie Wallace4, Laurel Sillerud5, Steven Eberhardt6, Robert Rosenberg6, Lesley Lomo7, Stefan Posse 1Department of Neurology, University of New Mexico, Albuquerque, NM, United States; 2Center of Magnetic Resonance Research, University of Minnesota; 3Cancer Research & Treatment Center, Univeristy of New Mexico; 4Department of Surgery, University of New Mexico; 5Biochemistry and Molecular Biology, University of New Mexico; 6Department of Radiology, University of New Mexico; 7Pathology, University of New Mexico Quantification of total Choline compounds in breast spectra is challenging due to the contamination of unsuppressed lipids. In vivo breast spectra in healthy controls were acquired using proton echo planar spectroscopic imaging. Localized spectra were fitted across the 4.0-2.0ppm range by LCModel using a basis-set with singlet resonances for tCho and lipid peaks. LCModel fitting enables identification of the tCho baseline and quantification of the peak area by spectral integration. In vivo tCho concentrations were consistent with literature values. This method is suitable for automatic tCho quantification of breast spectroscopic imaging data of low quality. 2797. Digital Breast Phantom for Evaluating Dynamic Accelerated Imaging Methods Leah Christine Henze1, Catherine J. Moran2, Matthew R. Smith2, Frederick Kelcz3, Alexey Samsonov3, Sean B. Fain2, Walter F. Block, 12 1Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; 2Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 3Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States Improving temporal resolution without compromising spatial resolution has the potential to improve differential diagnosis in breast cancer. Several accelerated imaging methods exist that may aid in this endeavor but it is difficult to quantitatively measure and compare their respective performance. To address this problem, we have created a digital breast phantom comprised of enhancing lesions surrounded by normal background breast tissue. This phantom provides realistic, simulated k-space data for both Cartesian and non Cartesian acceleration methods. We describe the creation of this phantom and demonstrate its use. Fang Liu1,2, Anat Kornecki3, Olga Shmuilovich3, Neil Gelman1,2 1Lawson Imaging, Lawson Health Research Institute, London, Ontario, Canada; 2Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 3Department of Diagnostic Imaging, St. Joseph's Health Center, London, Ontario, Canada Most previous quantitative studies using dynamic contrast enhanced MRI of the breast have analyzed either signal time evolution features or morphological features as predictors of malignancy. However, combined use of both types of features should provide stronger predictors. In this study, a time evolution feature (time to peak (TTP)) and a 3D morphological feature (spherical shape index (SSI)), both obtained from tumor regions segmented automatically with K-means clustering, were investigated as independent and combined predictors of malignancy. Results suggest that the combination provides stronger discrimination of malignant versus benign lesions than either feature alone. Jie Huang1, Lori Hoisington1, Sarah Schafer1, Xiaopeng Zong1, Kevin Berger1 1Department of Radiology, Michigan State University, East Lansing, MI, United States This study investigated using lesion fractional volume washout (WO) kinetic analysis for improving the characterization of suspicious contrast-enhancing breast lesions. The WO volume fraction was found to be significantly different between the biopsy-proven benign and malignant lesions of all the suspicious breast lesions with BI-RADS assessment of 4 or 5. It showed a potential to improve the positive predictive value of the biopsies by an improvement rate of 86.8%, and consequently would yield a 72.2% reduction rate to the total number of unnecessary biopsies. Giuseppe Petralia1, Luke Bonello1, Paul Summers1, Sara Raimondi2, Ala Malasevschi1, Roberto Di Filippi1, Dow-Mu Koh3, Marzia Locatelli4, Giuseppe Curigliano4, Massimo Bellomi1 1Radiology, Istituto Europeo di Oncologia, Milan, Lombardia, Italy; 2Epidemiology and Biostatistics, Istituto Europeo di Oncologia, Milan, Lombardia, Italy; 3Radiology, Royal Marsden Hospital, Sutton, United Kingdom; 4Medical Oncology, Istituto Europeo di Oncologia, Milan, Lombardia, Italy We performed a qualitative analysis of diffusion weighted magnetic resonance imaging (DW-MRI) of breast tumours to identify common semiotic characteristics, and a quantitative analysis in 28 patients to examine the correlation of DW-MRI with molecular prognostic factors, and to assess the interobserver variability in the calculation of ADC values. Hyper-intensity in DW images and low ADC values (mean 1.1 x 10-3mm2/sec) were common characteristics in the breast tumours studied. Interobserver variability was 20%.A marginally significant correlation between ADC value and percentage of PgR and possible higher mean ADC values for the LUMINAL A subtype warrant further study. Prostate Cancer - Clinical Hall B Wednesday 13:30-15:30 Tristan Barrett1, Andrew Gill1,2, Masako Kataoka1, Vincent J. Gnanapragasam3, Andrew Priest1,2, Ilse Joubert1, Mary McLean2,4, Martin J. Graves1, David J. Lomas1, John R. Griffiths2, David Neal3,5, Evis Sala1 1Radiology, Addenbrooke's Hospital, Cambridge, United Kingdom; 2Medical Physics, Addenbrooke's Hospital, Cambridge, United Kingdom; 3Urology, Addenbrooke's Hospital, Cambridge, United Kingdom; 4 Cambridge Research Institute, Cancer Research UK,, Cambridge, United Kingdom; 5Cambridge Research Institute, Cancer Research UK, Cambridge, United Kingdom Prostate cancer is the commonest malignancy in UK men. Androgen deprivation therapy (ADT) remains an important treatment. However, 51% eventually develop resistance, making it necessary to identify quantitative markers that demonstrate ADT response. We used dynamic-contrast-enhancement (DCE)-MRI to measure permeability parameters before and 3 months after ADT in 12 patients with biopsy-proven prostate cancer. There was a significant reduction in all parameters measured (Ktrans, kep, Ve, IAUGC-90), whereas normal tissue showed no significant change. These results suggest that DCE-MRI has potential to monitor ADT response and select to patients with AD resistance at early time-points, allowing consideration of other treatments. Michael A. Jacobs1,2, Vadappuram Chacko1, Baasil Okollie1, Tamara Lotan3, Katarzyna J. Macura1 1The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine; 3Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States By using a multiparametric approach to investigate the in-vivo and ex-viso characteristics of prostate cancer a better understanding of prostate cancer aggressiveness and tumor staging can be realized. This radiological-pathological correlation will assist in detection, localization, assessment of the tumor microenvironment. Such a comprehensive approach offers more power to evaluate prostate disease than any single measure alone. Greetje Groenendaal1, Maaike R. Moman1, Johannes G. Korporaal1, Paul J. van Diest2, Marco van Vulpen1, Marielle E.P. Philippens1, Uulke A. van der Heide1 1Radiotherapy, University Medical Center Utrecht, Utrecht, Netherlands; 2Pathology, University Medical Center Utrecht, Utrecht, Netherlands Sensitivity and specificity values of DW-MRI and DCE-MRI for prostate cancer are often based on the correspondence of imaging and pathology within relatively large volumes inside the prostate. However, for prognosis, therapy selection and focal therapy, decisions on a voxel level are required. We investigated at which spatial resolution validation of MR images with hematoxylin-eosin stained sections is meaningful. We found that the chance is small that matching tumor voxels are found on the MR images and pathology within a volume smaller than 0.4 cc. This puts limitations on the accuracy at which tumor volume and extent can be determined. 2804. Echo Planar Spectroscopic Imaging with Peak-Enhanced 2D-Capon Analysis for Prostate Studies Fred J. Frigo1, Andreas Ebel1 1GE Healthcare, Waukesha, WI, United States Two-dimensional echo planar spectroscopic imaging (EPSI) may be used for clinical evaluation of the human prostate. The results of EPSI studies are typically represented as the set of MRS absorption spectra in which the concentration of each metabolite can be determined on the basis of its frequency representation in the voxel of interest. In addition to frequency information, the damping characteristics of each metabolite can also be determined by using two-dimensional Capon analysis. This damping information may be used in conjunction with the frequency information to more easily identify metabolites during clinical diagnosis of EPSI prostate studies. 2805. 31P MR Spectroscopy for Prostate Cancer Characterization at 7Tesla Catalina Arteaga1, Uulke A. van der Heide1, Marco van Vulpen1, Peter R. Luijten2, Dennis W.J. Klomp2 1Radiotherapy, UMC Utrecht, Utrecht, Netherlands; 2Radiology, UMC Utrecht, Utrecht, Netherlands We showed the feasibility of obtaining 31P MRS in the prostate area at 7T with the use of anatomy imaging and optimized B0 shimming. Individual detection of PC, GPC, GPE and GPC was feasible, illustrating the benefit of going to higher spectral resolutions that can be obtained at higher fields like 7T. Niranjan Venugopal1,2, Axel Krieger3, Herve Momo Jeufnack4, Ken Bradshaw4, Boyd McCurdy5, Lawrence Ryner6 1Physics and Astronomy, University of Manitoba, Winnipeg, MB, Canada; 2Medical Physics, CancerCare Manitoba, Winnipeg, MB, Canada; 3Sentinelle Medical, Toronto, Ontario, Canada; 4Sentinelle Medical Inc.; 5Medical Physic, CancerCare Manitoba, Winnipeg, MB, Canada; 6National Research Council Institute for Biodiagnostics, Winnipeg, MB, Canada We present a comparison of a newly designed dual-channel, rigid endorectal coil for both imaging and spectroscopic imaging of the prostate with a standard, single-channel, inflatable endorectal coil, demonstrating a SNR improvement of up to ~500% in the near-coil area (where the prostate peripheral zone is located), and up to ~150% at depth (where the prostate central zone is located). This huge SNR improvement allows for greatly improved MR/MRSI imaging of the prostate. 2807. Short Echo Time in Vivo Prostate MRSI Niranjan Venugopal1, Boyd McCurdy2, Darrel Drachenberg3, Salem Al Mehari3, Aziz Alamri3, Gurudarshan Sandhu3, Sri Sivalingam3, Lawrence Ryner4 1Physics and Astronomy, University of Manitoba, Winnipeg, MB, Canada; 2Medical Physics, CancerCare Manitoba, Winnipeg, MB, Canada; 3Urology, University of Manitoba, Winnipeg, MB, Canada; 4National Research Council Institute for Biodiagnostics, Winnipeg, MB, Canada We present a robust method improve the quality of in vivo prostate MRSI data acquisition by utilizing an optimized conformal voxel technique coupled with a spatial-spectral excitation PRESS pulse sequence for short echo time acquisitions.The PRESS pulse sequence was modified to include the optimized conformal voxel MR spectroscopic imaging technique (CV-MRS). In vivo implementation of this optimized MRSI technique confirms the reduction in peripheral lipid contamination, and improved the quality of spectra throughout the prostate. In summary we have demonstrated the utility of short TE in vivo prostate MRSI acquisitions, which provides significant signal increase and reveal short TE metabolites to potentially improve prostate cancer detection. 2808. Clinical Prostate T1 Quantification Using a Magnetization-Prepared Spiral Technique Warren Foltz1, Masoom Haider2,3, Peter Chung1, Andrew Bayley1, Charles Catton1, Venkat Ramanan4, David Jaffray1, Graham Wright4, Cynthia Ménard1 1Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada; 2Medical Imaging, University Health Network, Toronto, Ontario, Canada; 3Medical Imaging, University of Toronto; 4Sunnybrook Research Institute, Toronto, Ontario, Canada A magnetization-prepared spiral imaging strategy with RF cycling has been adapted for time-efficient multi-slice clinical prostate T1 quantification at 1.5T. In vitro testing validated an overall robustness to RF offsets. Pilot studies in patients without prior external beam radiation demonstrated an equivalence between zonal T1, with reduced T1 in peripheral zone tumors. Intra-patient zonal T1 variabilities motivate individial measurements for dynamic studies of vascular metrics. SNR analysis identified useful region volumes for thermal-noise insensitive measurements, to guide protocol design for future voxel-based prostate T1 mapping. High RF insensitivity combined with time-efficiency suggests method potential for robust implementation on stronger magnets. 2809. Multi-Slice Parametric Mapping in Prostate DCE-MRI Ryan Alexander Priest1, Xin Li2, Ian J. Tagge2, William J. Woodward2, Tomasz M. Beer3,4, Charles S. Springer, Jr. 2,4, Mark G. Garzotto5,6 1Diagnostic Radiology, Oregon Health & Science University, Portland, OR, United States; 2Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States; 3Hematology/Oncology, Oregon Health & Science University, Portland, OR, United States; 4Knight Cancer Institute, Oregon Health & Science University, Portland, OR, United States; 5Urology, Oregon Health & Science University, Portland, OR, United States; 6Portland VA Medical Center, Portland, OR, United States Pharmacokinetic analysis of data generated using Dynamic-Contrast-Enhanced MRI (DCE-MRI) has proven to be a valuable tool in the evaluation of the vascular pathophysiology of prostate adenocarcinoma. With improved hardware, multi-slice parametric mapping has become feasible and could provide valuable insight to complement conventional T2*-weighted images. In this study multi-slice parametric mapping was performed with DCE-MRI data using both the standard model (SM) and the first generation shutter-speed model (SSM1). Parametric maps were then compared with biopsy results. 2810. Ability of Combined DTI and DCE MRI to Predict Pathologic Gleason Score Piotr Kozlowski1,2, Silvia D. Chang2, Edward C. Jones3, Ran Meng1, Nicholas Buchan4, S Larry Goldenberg, 4,5 1UBC MRI Research Centre, Vancouver, BC, Canada; 2Radiology, Univeristy of British Columbia, Vancouver, BC, Canada; 3Pathology and Laboratory Medicine, Univeristy of British Columbia, Vancouver, BC, Canada; 4Vancouver Prostate Centre, Vancouver, BC, Canada; 5Urologic Sciences, Univeristy of British Columbia, Vancouver, BC, Canada DTI and DCE MRI were carried out in 27 prostate cancer patients. Mean diffusivity, fractional anisotropy and pharmacokinetic modeling parameters calculated from MRI data were correlated with Gleason score determined by biopsy and prostatectomy specimens. Mean diffusivity and fractional anisotropy correlated significantly with Gleason score, as demonstrated by the Spearmans rank correlation test and the ordinal logistic regression modelling. These results strongly suggest that DTI MRI is capable of non-invasively grading prostate tumours. 2811. Investigation of Prostate Cancer Using Diffusion Weighted IVIM Imaging Jörg Döpfert1, Andreas Lemke1, Anja Weidner2, Lothar Rudi Schad1 1Department of Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany; 2Institute of Radiology and Nuclear Medicine, Heidelberg University, Mannheim, Germany In this work, the decrease of the apparent diffusion coefficient (ADC) in cancerous prostate tissue compared to healthy prostate tissue is investigated using the Intravoxel Incoherent Motion (IVIM) Theory. Moreover , the extracted parameters and the calculated parameter maps are analyzed with regard to the differentiation between cancerous and healthy tissue. Therefore, diffusion weighted images of the prostate of 9 patients with prostate carcinoma were acquired and evaluated, yielding a significant decrease of the ADC and the perfusion fraction in cancerous tissue compared to healthy tissue. The results suggest that the decrease of the ADC primarily comes from perfusion effects. 2812. Comparison of HASTE & EPI Diffusion Weighted Images in the Prostate Ben Babourina-Brooks1, Gary Cowin1, Deming Wang1 1Centre for Magnetic Resonance, University of Queensland, Brisbane, Queensland, Australia A comparison of two diffusion weighted imaging sequences, Echo Planar Imaging (EPI) and Half fourier Aquisition Single shot Turbo spin echo (HASTE), was conducted in the prostate. EPI, which is currently the main DWI method, is highly susceptible to artifacts, namely magnetic susceptibility and chemical shift. We propose to use a HASTE sequence, which is less affected by these artifacts, to gain more reproducible Apparent Diffusion Coefficient (ADC) values and increase ADC map quality. Advancements in this area will lead to more accurate prostate cancer localisation. Derya Yakar1, Stijn Heijmink, Jelle Barentsz, Christina Hulsbergen - Van de Kaa, Jurgen Fütterer, Tom Scheenen 1Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands Currently used techniques in localizing prostate cancer (Pca) have definite shortcomings. We studied the potential of 3D- magnetic resonance spectroscopic imaging (MRSI) with and without an endorectal coil (ERC) at 3T in improving the localization of Pca. Eighteen patients with histologically proven Pca underwent an MRSI examination with and without the use of an ERC. The areas under the receiver operating characteristic curve were improved for all of the readers with the use of an ERC. For one reader this improvement was statistically significant (p< .05). Overall the AUC for all readers was quite low, with and without the use of an ERC. Emphasis have to be made on the fact that these results concern an initial experience based on a first cohort of patients examined at 3T with 3D-MRSI in our institution. In our experience more recent data of patients examined with 3D-MRSI at 3T in our institution are far more promising due to higher signal-to-noise ratios resulting in better fitted spectra and less non ratable ROIs. 2814. Clinical Prostate T2 Quantification Using a Magnetization-Prepared Spiral Technique Warren Foltz1, Supriya Chopra1, Peter Chung1, Andrew Bayley1, Charles Catton1, David Jaffray1, Graham Wright2, Masoom Haider3,4, Cynthia Ménard1 1Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada; 2Sunnybrook Research Institute, Toronto, Ontario, Canada; 3Medical Imaging, University Health Network, Toronto, Ontario, Canada; 4Medical Imaging, University of Toronto A magnetization-prepared spiral imaging technique, termed T2prep, was adapted for robust time-efficient clinical prostate evaluation, and piloted in two prostate cancer cohorts. The patient groups presented with: (A) no prior history of external beam radiation; and (B) biochemical failure after radiotherapy. Cohorts were scanned (A) without and (B) with an endo-rectal coil in tandem with a torso phased-array, respectively. Prostate zonal and tumor T2 values supported known trends. For each cohort, an SNR analysis was performed to identify minimum region volumes for thermal-noise insensitive measurements, and to guide protocol design for future voxel-based anlaysis. 2815. Early Quantititative T1 and T2 Response of the Prostate Gland During Radiotherapy Warren Foltz1, Andy Wu1, Anna Kirilova1, Peter Chung1, Andrew Bayley1, Charles Catton1, David Jaffray1, Masoom Haider2, Cynthia Ménard1 1Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada; 2Medical Imaging, University Health Network, Toronto, Ontario, Canada Magnetization-prepared spiral imaging techniques were adapted for quantitative T2 and T1 characterization of early radiation response in patients with low/intermediate risk of localized cancer throughout 8-weeks of radiotherapy. Early central gland T2 elevation preceded persistent tumor T2 elevation, and late reduction in peripheral zone T2; observations which support a known loss of contrast in diagnostic images, and a complementary role for T2 in ADC and DCE radiation response evaluation. Zonal and tumor T1 measures were insensitive to radiotherapy. However, considerable inter-patient but minor intra-patient T1 heterogeneities support a sufficiency of baseline T1 scanning for serial quantitative perfusion analysis during radiotherapy. Cancer (Miscellaneous) Hall B Thursday 13:30-15:30 Monique Maas1, Doenja Lambregts1, Ronald van Dam2, Patty Nelemans3, Guido Lammering4, Rob Jansen5, Regina Beets-Tan1, Geerard Beets2 1Radiology, Maastricht University Medical Center, Maastricht, Limburg, Netherlands; 2Surgery, Maastricht University Medical Center, Maastricht, Limburg, Netherlands; 3Epidemiology, Maastricht University Medical Center, Maastricht, Limburg, Netherlands; 4Radiotherapy, Maastricht University Medical Center, Maastricht, Limburg, Netherlands; 5Medical Oncology, Maastricht University Medical Center, Maastricht, Limburg, Netherlands When - after neoadjuvant chemoradiation for rectal cancer - imaging could accurately select the complete responders, surgery might safely be omitted and patients can undergo a wait-and-see policy. This study aims to evaluate whether MRI at 1.5T is accurate enough to select patients for wait-and-see and can safely be used as a follow-up tool. Daisuke Takenaka1, Yoshiharu Ohno1, Keiko Matsumoto1, Hisanobu Koyama1, Yumiko Onishi1, Munenobu Nogami1, Nobukazu Aoyama2, Hideaki Kawamitsu2, Kazuro Sugimura1 1Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan; 2Division of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan FDG-PET/CT can assess morphological and metabolic information at same time, and widely utilized for N-stage assessment in non-small cell lung cancer (NSCLC) patients. In the last decade, short inversion time inversion recovery (STIR) turbo spin-echo (SE) imaging has been determined at least as valuable as PET/CT in this setting. Recently, diffusion-weighted image (DWI) is suggested as new technique for differentiation of metastatic lymph nodes from non-metastatic lymph nodes. The purpose of this study was to prospectively and directly compare capability of N-stage assessment among integrated FDG-PET/CT, STIR turbo SE imaging and DWI in NSCLC patients. Tatsuro Tsuchida1, Miwa Morikawa2, Yukihiro Umeda2, Masato Sasaki3, Tomohito Kamibayashi1, Hirohiko Kimura1 1Dept. of Radiology, University of Fukui, Fukui, Japan; 2Dept. of Respiratory Medicine, University of Fukui, Fukui, Japan; 3Dept. of Thoracic Surgery, University of Fukui, Fukui, Japan The purpose of this study was to examine the utility of DWI-MRI for the assessment of early response to chemotherapy in patients with advanced lung cancer by comparing FDG-PET. Twenty-two lung cancer patients received MRI, FDG-PET, and CT examination before and after 1 cycle of chemotherapy. Progression-free survival (PSF) between responder and non-responder against chemotherapy was compared by means of % change of ADC and SUV. Both index indicated that responder demonstrated significant longer PSF and DWI-MRI will be a promising tool for the assessment of the early response to chemotherapy. Hatsuho Mamata1, Junichi Tokuda1, Ritu Gill1, Robert F. Padera2, Robert E. Lenkinski3, David J. Sugarbaker4, Hiroto Hatabu1 1Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; 2Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States; 3Radiology, Beth Israel Decones Medical Center, Harvard Medical School, Boston, MA, United States; 4Thoracic surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States Solitary pulmonary nodule (SPN) is one of the most common findings in chest imaging. It is important to avoid unnecessary intervention for benign lesions, thereby lowering the associated mortality / morbidity. In this study, we applied perfusion MRI to evaluate perfusion characteristics of SPN and feasibility of perfusion MRI as a diagnostic tool to differentiate malignant from benign SPN. Perfusion MRI parameters and TI curve has great potential to differentiate malignant vs. benign SPN, thus to avoid unnecessary surgical interventions. Rob H. Ireland1,2, Omar S. Din2, James A. Swinscoe2, Edwin JR van Beek3, Matthew QF Hatton2, Jim M. Wild1 1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom; 2Academic Unit of Clinical Oncology, University of Sheffield, Sheffield, United Kingdom; 3Department of Radiology, University of Iowa, Iowa, IA, United States This preliminary work demonstrates the feasibility of pre-treatment assessment of lung ventilation and post-treatment detection of radiation-induced lung damage using 3He-MRI for NSCLC patients. Kavindra Nath1, Elliot C. Woods1, Seung Cheol Lee1, David S. Nelson1, Dennis B. Leeper2, Rong Zhou1, Lin Li1, Jerry D. Glickson1 1Radiology (Molecular Imaging Section), University of Pennsylvania, Philadelphia, PA, United States; 2Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, United States In vivo 31P magnetic resonance spectroscopy illustrates that human melanoma xenografts can be acidified by induction of hyperglycemia combined with administration of lonidamine, an inhibitor of mitochondrial respiration. In melanoma xenograft (10-13 mm diameter), intracellular pH (pHi, measured by chemical shift of the Pi resonance) was reduced by ~0.7 unit during i.v. infusion of glucose (0.6 M) for 120 min along with administration of lonidamine (50 mg/kg). Preliminary result of this study shows that lonidamine combined with hyperglycemia acidified human melanoma xenografts by reducing pHi, a more critical parameter for thermosensitization to improve tumor response to alkylating agents. 2822. Monitoring Bone Marrow Changes During Chemoradiotherapy Using MRI Fat Quantification Mark Bydder1, Yun Liang2, Huanzhou Yu3, Ann Shimakawa3, Jean Brittain3, Graeme Bydder1, Loren Mell2 1Radiology, University of California San Diego, San Diego, CA, United States; 2Radiation Oncology, University of California San Diego, San Diego, CA, United States; 3GE Healthcare, Applied Science Lab, United States The goal of this study was to evaluate a non-invasive magnetic resonance imaging method of fat quantification as a measure of yellow bone marrow in the pelvis and spine. This is a new technology that will enable monitoring of response to therapy and assessment of the effectiveness of strategies to reduce hematology toxicity. Eiki Nagao1, Takashi Yoshiura1, Akio Hiwatashi1, Koji Yamashita1, Hironori Kamano1, Yukihisa Takayama1, Tuvshinjargal Dashjamts1, Makoto Obara2, Tomoyuki Okuaki2, Hiroshi Honda1 1Clinical radiology of Kyushu-university, Fukuoka, Japan; 2Philips Electoronics Japan Motion-sensitized driven-equilibrium (MSDE) sequence has been reported to effectively suppress signals from flowing blood in vessels that can mimic the brain metastases on post-contrast T1-weighted images. We performed an observer test to determine whether use of a 3D turbo spin-echo (TSE) sequence with MSDE increases radiologistsf diagnostic performances in detecting brain metastases comparing to a conventional 3D gradient-echo sequence (MPRAGE). A jackknife free-response receiver operating characteristic (JAFROC) analysis showed that TSE with MSDE increases radiologistsf diagnostic performances compared to MPRAGE. The reading time was also significantly shortened by use of MSDE. Jacobus FA Jansen1, Diane Carlson1, Bhuvanesh Singh1, Hilda Stambuk1, Ya Wang1, Dennis Kraus1, Richard Wong1, Snehal Patel1, Jatin Shah1, Jason Koutcher1, Amita Shukla-Dave1 1MSKCC, NY, United States Pretreatment DCE-MRI was performed on neck nodal metastases of 12 patients who underwent surgery. Surgical specimens were analyzed with immunohistochemistry (IHC) assays for Ki-67 (reflecting cellular proliferation) and HIF-1α (hypoxia inducible transcription factor). Spearman correlation was used to correlate DCE-MRI and molecular marker data. Significant correlation results were observed between DCE-MRI data (Ktrans and ve) and tumor hypoxia, and proliferation as measured by Ki67 and HIF-1į expression levels, respectively. Future studies with larger patient populations need to be carried out to confirm pretreatment DCE-MRI findings and molecular marker results in biopsy samples for better patient management. Martin D. Pickles1, Lindsay W. Turnbull1 1Centre for MR Investigations, University of Hull, Hull, East Yorkshire, United Kingdom Oncology patients undergo multiple imaging investigations to stage their disease. The aim of this study was to investigate the feasibility of a focused primary tumour (breast or prostate) examination in combination with a WB-MRI for staging of distant disease. If successful we propose the addition of this technique could allow the omission of other examinations, such as radionuclide imaging, thereby streamlining the current imaging pathway. We conclude that focused primary tumour examinations in combination with a WB-MRI for staging of distant disease is feasible. However, the technique needs to validated in a much larger cohort than the one studied. Jing Liu1, XiaoYing Wang1, XueXiang Jiang1 1Department of Radiology, Peking University First Hospital, BeiJing, China The study aimed to explore the role of Whole-body DWI in clear cell renal cell carcinoma (RCC) and obtain the imaging characteristics of metastases. Ten patients with histologically confimed clear cell RCC and possible metastatic lesions were underwent standard Whole-body DWI, chest CT and routine MR examinations before chemotherapy. The results showed that the whole body DWI was very sensitive to the metastatic lesions in clear cell RCC and DWI showed its high rate of detection in pulmonary metastases. Whole body DWI had revealed great potential in metastatic screening of clear cell RCC. Michael A. Jacobs1, Li Pan2, Katarzyna J. Macura1, Thorsten Feiweier3, Wilhelm Horger3, Christine Lorenz2, Richard L. Wahl1 1The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2Center for Applied Medical Imaging, Siemens Corporation, Corporate Research, Baltimore,, MD, United States; 3Siemens AG, Healthcare Sector, Magnetic Resonance, Germany By using Whole Body MR and PET/CT approach to investigate metastatic disease can lead a better understanding of cancer aggressiveness. Functional imaging such as DWI/ADC, DCE-MR and 11C Choline PET is feasible and thus, combined DWI/ADC mapping, and PET/CT provides radiological biomarkers of molecular environment and could provide targets imaging treatment response. B1 +/- Mapping Hall B Monday 14:00-16:00 Alexis Amadon1, Nicolas Boulant1, Martijn Anton Cloos1, Eric Giacomini1, Christopher John Wiggins1, Michel Luong2, Guillaume Ferrand2, Hans-Peter Fautz3 1Neurospin, CEA/DSV/I2BM, Gif-sur-Yvette, France; 2IRFU, CEA/DSM, Gif-sur-Yvette, France; 3Siemens Healthcare, Erlangen, Germany Efficient mitigation of the RF inhomogeneity using transmit coil arrays relies on the knowledge of the individual B1-maps. As the number of transmit channels increases, so does the acquisition time of all maps. Here we focus on a fast 2D sequence proposed by Fautz et al. which we adapt for multi-slice B1-mapping. We compare its results with that of the 3D AFI sequence on a spherical phantom surrounded by 8 transmit elements at 7T. We show comparable performance with a 12-fold increase in speed, making accurate B1-mapping of the human head feasible in 1.5 minutes for 8 transmit channels. 2829. B1 Mapping with Whole Brain Coverage in Less Than One Minute Steffen Volz1, Ulrike Nöth1, Ralf Deichmann1 1Brain Imaging Center (BIC), Goethe University Frankfurt, Frankfurt am Main, Germany There is great demand for fast B1 mapping techniques, e.g. for correction of quantitative T1 maps. However, most methods suffer from long experiment durations. The technique presented here is based on magnetization prepared FLASH imaging with specially designed preparation and excitation pulses to allow for multislice imaging, speeding up the acquisition. Systematic errors due to relaxation effects are avoided by intensity correction of individual k-space lines. The method allows for fast B1 mapping with whole brain coverage, an in-plane resolution of 4 mm, a slice thickness of 3 mm, and an accuracy of 2% within 46 s. 2830. Fast RF Flip Angle Calibration by Bloch-Siegert Shift Laura Sacolick1, Ling Sun2, Mika W. Vogel1, Ileana Hancu3 1GE Global Research, Garching b. Munchen, Germany; 2GE Healthcare, Waukesha, WI, United States; 3GE Global Research, Niskayuna, NY, United States Here we present a novel method for automated RF flip angle calibration based on the Bloch-Siegert shift. The Bloch-Siegert shift is an effect where spin resonance frequency shifts when an off-resonance RF field is applied. Two off-resonance RF pulses were added to a slice-selective spin echo sequence. The off-resonance pulses induce a phase shift in the acquired signal that is proportional to B12. The signal is spatially localized in two dimensions- by slice selection and readout filter, and the signal weighted average B1 over the slice is calculated. This calibration from a starting system transmit gain to measured average flip angle is used to calculate the transmit gain setting needed to produce the desired flip angle. This is shown here at 3 Tesla in the brain, shoulder, abdomen, breast, and wrist with a total scan time for a robust implementation of 1.6 seconds. 2831. Fast and Robust B1 Mapping at 7T by the Bloch-Siegert Method Mohammad Mehdi Khalighi1, Laura I. Sacolick2, W Thomas Dixon3, Ron D. Watkins4, Sonal Josan4, Brian K. Rutt4 1Applied Science Lab, GE Healthcare, Menlo Park, CA, United States; 2Imaging Technologies Lab, General Electric Global Research, Garching b. Munchen, Germany; 3General Electric Global Research, Niskayuna, NY, United States; 4Department of Radiology, Stanford University, Stanford, CA, United States B1+ mapping is a critical step in the design of RF pulses for parallel transmit systems. We used the Bloch-Siegert (BS) B1+ mapping method and a 2-channel parallel transmit enabled 7T scanner to produce fast, robust and accurate B1+ maps through the human brain. Both B1+ magnitude and phase are obtained from a single sequence, employing +/-4kHz off-resonance BS pulses. B1+ magnitude and phase maps acquired with a 26s BS scan are compared with those acquired with a 640s classical double angle scan, showing that the BS method is a very good candidate for efficient B1+ mapping at 7T. 2832. Practical Vector B1 Mapping at 7T Douglas Kelley1,2, Janine Lupo2 1Applied Science Laboratory, GE Healthcare, San Francisco, CA, United States; 2Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States Compensation of B1 variations in vivo requires mapping both the magnitude and the phase of each channel's RF magnetic field. Since the field distribution is strongly dependent on the specific size, shape, and positioning of the tissue, such mapping must be made for each subject. We present a practical method for acquiring these maps within 10 minutes in phantoms and human subjects at 7T. 2833. Compressive B1+ Mapping: Towards Faster Transmit Coil Sensitivity Mapping Mariya Doneva1, Kay Nehrke2, Alfred Mertins1, Peter Börnert2 1Institute for Signal Processing, University of Lübeck, Lübeck, Germany; 2Philips Research Europe, Germany The potential to accelerate the B1+ mapping measurement by means of compressed sensing (CS) was investigated. Joint sparsity constraint accounting for the common sparsity support in different TX channels, and higher dimensional undersampling space, also including the coil dimension, allow for considerable acceleration even for the low resolution data acquired in B1+ mapping. The basic feasibility of the proposed method is evaluated on simulations and in vivo data from a 3T 8-channel parallel transmit system. 2834. Simultaneuous B0 and High Dynamic Range B1 Mapping Using an Adiabatic Partial Passage Pulse Kim Shultz1, Greig Scott1, Joelle Barral1, John Pauly1 1Electrical Engineering, Stanford University, Stanford, CA, United States We present a simultaneous δ B0 and high-dynamic range B1 mapping technique using an adiabatic partial passage pulse. The double angle method, the gold standard for B1 mapping, requires 66% longer to acquire the same B1 range. The high dynamic range is useful for mapping the fields from ablation wires or surface coils, where significant B0 variation will also be present. 2835. Fast B1+ Mapping with Validation for Parallel Transmit System in 7T Joonsung Lee1, Borjan Gagoski1, Rene Gumbrecht1,2, Hans-Peter Fautz3, Lawrence L. Wald4,5, Elfar Adalsteinsson1,5 1Electrical engineering and computer science, Massachusetts Institute of Technology, Cambridge, MA, United States; 2Physics, Friedrich-Alexander-University Erlangen, Erlangen, Germany; 3Siemens Healthcare, Erlangen, Germany; 4Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Cambridge, MA, United States; 5Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, United States We present a fast B1+ mapping method for parallel transmit system and validate the performance on water phantom in 7T. The measured flip angle matches with the flip angle simulated by the Bloch equation. 2836. Image-Guided Radio-Frequency Gain Calibration for High-Field MRI Elodie Breton1, KellyAnne McGorty1, Graham C. Wiggins1, Leon Axel1, Daniel Kim1 1Research Radiology - Center for Biomedical Imaging, New York University Langone Medical Center, New York, NY, United States The purpose of this study was to develop a rapid, image-guided RF transmitter gain calibration procedure for high-field MRI and evaluate its performance through phantom and in vivo experiments at 3T and 7T. Using a single-shot TurboFLASH pulse sequence, a series of saturation-no-recovery images was acquired by varying the flip angle of the preconditioning pulse. In the resulting images, the signal null occurs in regions where the flip angle of the preconditioning pulse is 90°, and the mean signal within a region-of-interest can be plotted as a function of the nominal flip angle to quantitatively calibrate the RF transmitter gain. 2837. No Inversion Double Angle Look-Locker (NiDALL) for Flip Angle Mapping Trevor Wade1,2, Charles McKenzie1,3, Brian Rutt4 1Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada; 2Biomedical Engineering, The University of Western Ontario, London, ON, Canada; 3Medical Biophysics, The University of Western Ontario, London, ON, Canada; 4Diagnostic Radiology and Richard M Lucas Center for Imaging, Stanford University, Stanford, CA, United States The double angle Look-Locker method is an efficient 3D method of mapping transmit B1 inhomogeneity. It makes uses inversion pulses and samples the recovering magnetization using SPGR trains at two different angles. This leads to two time constants that can be combined to find the achieved flip angle. If the SPGR trains at the two angles are interleaved the inversion pulses can be omitted entirely, and the same information can still be extracted. This reduces SAR, simplifies data analysis and still yields nearly the same performance in terms of measuring the flip angle. Lin Tang1, Tamer S. Ibrahim2 1School of Electrical and Computer Engineering, University of Oklahoma; 2Departments of Bioengineering and Radiology, Univeristy of Pittsburgh, Pittsburgh, PA, United States In this work, using 3D numerical simulations and verifications with a 7T scanner equipped with a transmit array system we conduct a comprehensive study using B1 shimming for potential 7T whole-body applications. Different from previous works [2], this study includes the optimizations of the B1+ field, local/average SAR and the resulting temperature elevation in the tissue. 2839. Simulation and Comparison of B1+ Mapping Methods at 3T Christopher Thomas Sica1, Zhipeng Cao1, Sukhoon Oh1, Christopher M. Collins1 1Penn State College of Medicine, Hershey, PA, United States RF inhomogeneity greatly affects the quality of MR imaging at high field strength, and compensation methods typically require accurate B1+ maps for optimum performance. Comparison of B1+ mapping methods based on experimental results alone is limited by lack of knowledge of the true B1+ field distribution. MRI simulation allows for comparison of the true, input B1+ field distribution with a simulated map. This study simulates AFI and a flip angle series method at 3T, utilizing MRI and electromagnetic field simulations. The simulation maps correspond closely to the input B1+ and one another. Experimental maps deviate significantly from one another. B1 Mapping Hall B Tuesday 13:30-15:30 2840. 3D Phase Sensitive B1 Mapping Steven Paul Allen1, Glen R. Morrell2, Brock Peterson1, Daniel Park1, Josh Kaggie2, Ernesto Staroswiecki3, Neal K. Bangerter1 1Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT, United States; 2Department of Radiology, University of Utah, Salt Lake City, UT, United States; 3Department of Radiology, Stanford University, Stanford, CA, United States Accurate quantification of tissue sodium concentration is an important component of several potential applications of sodium MRI. Quantitative analysis of sodium concentrations requires accurate measurement of B1. However, the low SNR typical in sodium MRI makes accurate B1 mapping in a reasonable time challenging. Phase-sensitive B1 mapping techniques are particularly robust in low SNR environments. In this work, we apply phase sensitive B1 mapping to sodium MRI, and compare it to a standard dual angle B1 mapping method. The phase sensitive method is shown to perform much better than the dual angle method, allowing rapid acquisition of reliable sodium B1 maps. 2841. Image Inhomogeneity Correction in Human Brain at High Field by B1+ and B1- Maps Hidehiro Watanabe1, Nobuhiro Takaya1, Fumiyuki Mitsumori1 1Environmental Chemistry Division, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan We propose a correction method of image inhomogeneity at high field. The inhomogeneity is originated from B1- and measurable B1+. We confirmed that a ratio map of B1- to B1+ (ρ) has a similar spatial pattern throughout human various brains from experimental results. The ratio map ρ in human brain was calculated from B1+ maps and images obtained with adiabatic pulses. Then, B1- was calculated by ρ× B1+. Homogeneous intensity was achieved in the corrected images by B1+ and B1-. Water fractions in gray and white matters obtained from corrected M0 image were in good agreement with reported values. 2842. Signal to Noise Ratio Analysis of Bloch-Siegert B1+ Mapping Mohammad Mehdi Khalighi1, Laura I. Sacolick2, Brian K. Rutt3 1Applied Science Lab, GE Healthcare, Menlo Park, CA, United States; 2Imaging Technologies Lab, General Electric Global Research, Garching b. Munchen, Germany; 3Department of Radiology, Stanford University, Stanford, CA The Bloch-Siegert method (BS) has been recently introduced as a fast, robust and accurate method for B1+ mapping. To compare it with other existing methods, we derived analytical expressions for SNR in BS, Actual Flip Angle Imaging (AFI) and Double Angle (DA) B1+ maps. Both theoretical and experimental comparisons show that the BS method has a higher SNR at low flip angles than the other methods, despite the shorter scan time of the BS method, making it a promising choice for B1+ mapping for parallel transmit pulse design, especially in situations where there is highly non-uniform B1+ across the object. 2843. Sa2RAGE - A New Sequence for Rapid 3D B1+-Mapping with a Wide Sensitivity Range Florent Eggenschwiler1, Arthur Magill1,2, Rolf Gruetter1,3, José P. Marques1,2 1EPFL, Laboratory for Functional and Metabolic Imaging, Lausanne, Vaud, Switzerland; 2University of Lausanne, Department of Radiology, Lausanne, Vaud, Switzerland; 3Universities of Geneva and Lausanne, Department of Radiology, Switzerland Sa2RAGE is based on the rapid acquisition of two images with low flip angles just before and after a saturation pulse. The ratio of the signals from the images can be linked to a specific B1+. Optimization of the sequence parameters allowed the derivation of a protocol that performs 3D B1+-mapping in ~30s (matrix size 64x64x16) with limited T1 dependence. Experimental work showed the accuracy of the B1+-mapping over a 10 fold range of B1+. In-vitro and in-vivo B1+ maps were performed to demonstrate the applicability of the method on the context of parallel transmission. 2844. Smoothing and Interpolation of In-Vivo B1+ Images Andreas Petrovic1,2, Yiqiu Dong3, Stephen Keeling3, Rudolf Stollberger1 1Institute of Medical Engineering, University of Technology Graz, Graz, Austria; 2Ludwig Boltzmann Institute for Clinical Forensic Imaging, Graz, Austria, Austria; 3University of Graz MR images at high field strengths (≥1.5T) suffer from artifacts caused by the inhomogeneity of the RF excitation field B1+ in the human body. Measurements of B1+ can be used for the correction of those artifacts. However, these B1+-images suffer from perturbations themselves and have to be smoothed and interpolated. In this work a new variational approach for smoothing is compared to a standard median filter for test images, as well as real in-vivo data. Simulations show that the variational approach combined with an outlier suppression algorithm outperforms the median filter in terms of accuracy and precision. In contrast to the median filter the variational approach produces very smooth results that are physically likely. 2845. Flow, Chemical Shift, and Phase-Based B1 Mapping W Thomas Dixon1, Laura Sacolick2, Florian Wiesinger2, Mika Vogel2, Ileana Hancu1 1GE Global Research Center, Niskayuna, NY, United States; 2GE Global Research Center, Munich, Germany B1 maps help scan set up and then aid in extracting quantitative results. Maps can be made by comparing either amplitudes or phases of two different images. Phase methods, with no waiting for T1, are fast. Phase avoids T1 issues but what about phase effects from flow and the chemical shift of fat? With a Bloch-Siegert, phase-based method, steady 0.5 m/s flow shifts phase 120o but leaves calculated B1 unchanged. Similarly, oil and water indicate the same B1 regardless of the fat-water phase difference. These results portend robust, phase-based B1 maps. Ryutaro Nakagami1,2, Masayuki Yamaguchi1, Akira Hirayama1,3, Akira Nabetani3, Atsushi Nozaki3, Takumi Higaki4,5, Natsumaro Kutsuna4,5, Seiichiro Hasezawa4,5, Hirofumi Fujii1,5, Mamoru Niitsu6 1Functional Imaging Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan; 2Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, Japan; 3GE Healthcare Japan, Ltd., Hino, Tokyo, Japan; 4Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, Japan; 5Institute for Bioinformatics Research and Development, Japan Science and Technology Agency, Chiyoda, Tokyo, Japan; 6Faculty of Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, Japan There has been growing interest in MR imaging studies of small animal models of human diseases as small animal MRI systems using a combination of 3.0 Tesla whole-body scanners and highly sensitive solenoid coils, which provides high spatial resolution and high sensitivity, as they are preferable for translational research. In this study, we demonstrate the feasibility of these MRI systems for quantitative MRI research by showing B1+ homogeneity in the mouse brain. In vivo B1+ maps were obtained by a rapid B1+ field mapping technique using a SPGR sequence and a brand-new calculation method for determining the 180° null signal. 2847. Rapid RF Field Mapping Using a Slice-Selective Pre-Conditioning RF Pulse Sohae Chung1, Daniel Kim1, Elodie Breton1, Leon Axel1 1Radiology, NYU Langone Medical Center, New York, NY, United States The B1 field uniformity plays an important role in determining the image quality in MRI, since such an RF pulse excitation causes flip angle variations that confound quantitative results. In this study, we describe a novel and efficient method for rapid B1 mapping using a slice-selective pre-conditioning RF pulse followed by TurboFLASH pulse sequence. This method is insensitive to off-resonance, with less than 1.4% B1 measurement error up to 500Hz off-resonance and the total scan time is less than 2s with SR module. Therefore, this method can be used for quantitative MRI applications that require fast B1 calibration. 2848. Fast Phase-Modulated B1+ Mapping in the Low Flip-Angle Regime Astrid L.H.M.W. van Lier1, Johannes M. Hoogduin2, Dennis J.W. Klomp2, Jan J.W. Lagendijk1, Cornelis A.T. van den Berg1 1Radiotherapy, UMC Utrecht, Utrecht, Netherlands; 2Radiology, UMC Utrecht, Utrecht, Netherlands In high-field MRI, phased-arrays are used to mitigate RF issues as excitation field inhomogeneities. In order to design RF pulses that can produces a desired excitation field, the B1+ field per coil must be mapped. We show that it is possible to measure B1+ maps for phased arrays in the low flip angle regime using phase-modulation (PMLF). This technique was validated by a contemporary high-flip angle technique and electromagnetic simulations. The advantages of the PMLF technique over the high-flip angle techniques are its low SAR cost and higher speed. Stephan Orzada1,2, Stefan Maderwald1,2, Benedikt Poser1,3, Andreas K. Bitz1,2, Harald H. Quick1,2, Mark E. Ladd1,2 1Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen, NRW, Germany; 2Department for Radiology and Neuroradiology, University Hospital Essen, Essen, NRW, Germany; 3Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, Netherlands Signal dropouts in high and ultra-high field MRI pose a substantial problem. Several approaches including transmit SENSE and RF shimming have been proposed. Here we propose a new imaging scheme to tackle this challenge. Using TIAMO, two or more inhomogeneous images acquired using different RF-transmit modes are combined to one homogeneous image. The cost in time for multiple acquisitions can be partially compensated by using the different acquisitions to generate virtual receive channels in a parallel imaging reconstruction. A mathematical theory is developed, and the results of phantom studies as well as first 7T in vivo abdominal imaging are presented. 2850. Enhanced Parallel Imaging Acceleration with a B1 Accelerated Reconstruction Sequence (BARS) Gigi Galiana1, Jason P. Stockman1, Robert Todd Constable1 1Diagnostic Radiology, Yale University, New Haven, CT, United States This work presents an approach to accelerated imaging via RF and surface coil localization using a multiwindow acquisition. The sequence can be described as creating effective sensitivity profiles for each acquisition window using the in-plane RF profiles to multiply and sculpt the sensitivity profiles of multichannel receivers. Rectangular RF profiles are chosen so as to efficiently encode along the phase encode-direction, improving the ability to unwrap aliasing caused by extreme undersampling along this direction. We present both numerical studies and experimental verification of the approach. 2851. Comparison of Different Methods for B1+/flip Angle and Reception Sensitivity Mapping Valentina Hartwig1,2, Nicola Vanello3, Giulio Giovannetti1, Maria Fillomena Santarelli1, Luigi Landini3 1Institute of Clinical Physiology, CNR, Pisa, Italy, Italy; 2Department of Electrical Systems and Automation, University of Pisa, Pisa, Italy, Italy; 3Department of Information Engineering, University of Pisa, Pisa, Italy, Italy Knowledge of transmission field B1+, and reception sensitivity maps is important in high field (>=3T) human Magnetic Resonance (MR) imaging for several aspects: these include post acquisition correction of intensity inhomogeneities, that may affect the quality of images, and modelling and design of radiofrequency (RF) coils and pulses. Moreover, in recent works, it has been demonstrated that B1 maps can be used for the direct calculation of tissues electrical parameters and for estimating the local Specific Absorption Rate (SAR) in vivo. In this study a comparison among known methods for B1+/flip angle and reception sensitivity mapping is introduced. 2852. Simulataneous B1 and B0 Mapping at 7T Walter RT Witschey1, Ravinder Reddy1, Mark A. Elliott1 1Radiology, University of Pennsylvania, Philadelphia, PA, United States A modification of the actual flip angle (AFI) method for measuring B1 is presented which simultaneously acquires spatial maps of both B0 and B1, allowing for accurate calculation of the radiofrequency field in the presence of off-resonance effects. An analytical expression for the actual B1 field is derived, given the apparent flip angle and the B0 map. Application of the new method is demonstrated at 7 tesla in phantom images. B1 Insensitive RF Hall B Wednesday 13:30-15:30 2853. BIR-4 Based B1 and B0 Insensitive Velocity Selective Pulse Trains Eric C. Wong1, Jia Guo2 1Radiology and Psychiatry, UC San Diego, La Jolla, CA, United States; 2Bioengineering, UC San Diego The BIR-4 pulse was recently shown to be useful for B1 and B0 insensitive T2 preparation. We report here an extension of this concept that includes the use of symmetrical gradient pulses inserted at the zero points of the BIR-4 pulse to impart velocity selectivity. The resulting velocity selective module is time efficient, and has better B1 insensitivity than existing methods based on adiabatic double spin echoes. Application to velocity selective arterial spin labeling is demonstrated. 2854. Broadband, Shallow Tip NMR Pulse Design Providing Uniform Tipping in Inhomogeneous RF Fields Hui Liu1, Gerald Matson1,2 1CIND, Veterans Affairs Medical Center, San Francisco, CA, United States; 2Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, United States Although high-field MRI offers increased signal-to-noise (S/N), the non-uniform tipping produced by conventional RF pulses leads to spatially dependent contrast and sub-optimal S/N, thus complicating the interpretation of the MR images. The aim of this research was to develop broadband RF pulses with immunity to B1 inhomogeneity. To accomplish this, we developed an optimization routine based on optimal control theory to design RF pulses with a desired range of immunity to B1 inhomogeneity and to resonance offset. The resulting pulses were more efficient than analogous pulses in the literature. These pulses have promise for certain MRI experiments at high field. 2855. Adiabatic Pulses Revisited Through Averaging Bahman Tahayori1,2, Leigh Andrea Johnston1,2, Peter Mark Farrell1,2, Iven Michiel Yvonne Mareels1,2 1EEE Department, The University of Melbourne, Melbourne, Victoria, Australia; 2NICTA Victoria Research Laboratory, Melbourne, Australia In this paper, the Bloch equation is scaled and averaged consequently to find the magnetization behaviour in a simple way with a negligible error for adiabatic passages. The novel framework presented here may be used to optimise the modulation functions of the adiabatic passages. 2856. Hyperbolic Secant Parameter Optimization for Non-Selective Inversion at 7 T Jay Moore1,2, Marcin Jankiewicz1,3, Adam W. Anderson1,4, John C. Gore1,4 1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 2Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, United States; 3Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; 4Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States Results include 3D δB0 and B1+ field maps in the human brain at 7 T. Hyperbolic secant pulses with a range of bandwidths are evaluated for non-selective inversion uniformity in this context. Numerical optimization of hyperbolic secant waveform parameters (β and μ) is shown to result in noticeably improved inversion uniformity as compared to pulses with the same bandwidth and μ=5. 2857. B1 Insensitive Genetically Altered Refocusing Pulses for Ultrahigh Field Spin Echo Imaging Aaron Christopher Hurley1,2, Andrew Peters1, Uwe Aickelin2, Li Bai2, Penny Anne Gowland1 1SPMMRC, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Computer Science, University of Nottingham, United Kingdom Urgurbil et al. proposed the use of a Numerically Optimised Modulation (NOM) scheme to improve the adiabaticity over the whole length of a BIR4 pulse and this method provides better performance for shorter pulses. NOM resamples the AM and FM functions with reference to the adiabatic condition and is restricted to looking at on-resonance effects. Following from this work, we attempted to optimize the resampling function via a Genetic Algorithm. The evaluation function considers B1 and B0 inhomogeneities to tailor the optimization to 7T conditions, requiring the study of off-resonance behaviour. Jay Moore1,2, Marcin Jankiewicz1,3, Adam W. Anderson1,4, John C. Gore1,4 1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 2Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, United States; 3Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; 4Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States Numerical optimization of the amplitudes and phases of a series of block-shaped sub-pulses was used to generate a 1.2 kHz bandwidth, 90° excitation pulse that is highly insensitive to the variations in the RF transmission field observed in the human brain at 7 T. This pulse serves as an example of the value of RF pulse design in providing an effective and cost-free alternative to technologies such as multiple-channel transmission for the purpose of achieving flip-angle uniformity at high field. 2859. An Optimized Composite Refocusing Pulse for Ultra-High Field MRI Marcin Jankiewicz1,2, Jay Moore1,3, Adam W. Anderson1,4, John C. Gore1,4 1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 2Department of Radiology, Vanderbilt University, Nashville, TN, United States; 3Department of Physics, Vanderbilt University; 4Department of Biomedical Engineering, Vanderbilt University A design of a composite refocusing pulse suitable for use in human imaging at 7T is presented here. With the assumption that it is preceded by a slice-selective excitation, the refocusing solution is immune to inhomogeneities within a predefined space of B1+ and δB0 values for 7T human head imaging. 2860. Slice-Selective Broadband Refocusing Pulses with B1 Immunity Martin Janich1,2, Rolf F. Schulte2, Markus Schwaiger3, Steffen J. Glaser1 1Department of Chemistry, Technische Universität München, Munich, Germany; 2Imaging Technologies, GE Global Research, Munich, Germany; 3Institute for Nuclear Medicine, Technische Universität München, Munich, Germany Broadband radio-frequency pulses are of great interest for reducing chemical shift displacements, anomalous J coupling, and increasing spectral selectivity. In this study broadband refocusing pulses with immunity to B 1 variations are designed using optimal control theory. The pulse design concentrates on posing least constrains on the optimization. The refocusing pulse presented here reaches a ratio of pulse bandwidth to peak RF amplitude of 2.1 and immunity of -10 % to +20 % B 1 variations. The optimized pulse is compared to a broadband SLR pulse, and validated experimentally. 2861. B1 Insensitive MLEV-4 Pulse Sequence for T2-Prep Mitsuharu Miyoshi1, Naoyoki Takei1, Masaaki Akahane2, Yasushi Watanabe3, Tetsuji Tsukamoto1 1Japan Applied Science Laboratory, GE Healthcare Japan, Hino, Tokyo, Japan; 2Radiology, University of Tokyo, Tokyo, Japan; 3Radiological Technology, University of Tokyo Hospital, Tokyo, Japan T2-prep is important for cardiovascular applications. However, because of B1 inhomogeneity on 3T, inhomogeneous signal loss occurs. T2-prep often uses MLEV-4 type sequence. In this study, B1 insensitive MLEV-4 type preparation pulse was designed and B1 and flow sensitivity were measured. Flip angle of MLEV-4 sequence was modified to (90x,140y,-200y,-140y,200y,-90x). Because at least two of the refocus pulses became near to 180 degree between -20% and +40% of delta B1, magnetizations were refocused correctly and became insensitive to B1 inhomogeneity. This preparation pulse suppressed flow signal and can also be used as flow saturation preparation pulse. 2862. Zoomed Spin-Echo Echo Volumar Imaging of the Mouse Brain in Vivo Using Adiabatic Pulses Julien Flament1, Sidi Mohamed Ould Ahmed Ghaly1, Benjamin Marty1, Céline Giraudeau1, Sébastien Mériaux1, Gilles Bloch1, Denis Le Bihan1, Franck Lethimonnier1, Julien Valette1, Fawzi Boumezbeur1 1NeuroSpin, I²BM, Commissariat ą l'Energie Atomique, Gif-sur-Yvette, France Many developments in the field of fast preclinical imaging are based on EVI sequences. We propose here an optimized protocol designed for preclinical in vivo imaging combining a quadrature surface coil with a zoomed Spin Echo EVI sequence using two orthogonal slice-selective adiabatic pulses (designated as ZEVIA) for volume selection. Brain coverage and time resolution are improved substantially without any drawbacks in the mouse brain in vivo at 7T. Ronald J. Beyers1, Yaqin Xu1, Michael Salerno2, Stuart S. Berr3, Craig H. Meyer1, Frederick H. Epstein1,3, Brent A. French1,2 1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 2School of Medicine, University of Virginia, Charlottesville, VA, United States; 3Radiology, University of Virginia, Charlottesville, VA, United States T2w MRI of the heart allows imaging post-infarct myocardial edema -- a key indicator of area at risk and possibly salvagable tissue. For high-field, 7 Tesla imaging in mice, we compared composite and adiabatic RF pulses in T2-Prep sequences. By simulation, phantom and in vivo imaging, we developed a flexible adiabatic T2-Prep method for whole-heart imaging of myocardial edema from onset within hours through resolution past the 20 day point. MRI of Conductivity Hall B Thursday 13:30-15:30 2864. Propagating RF Phase: A New Contrast to Detect Local Changes in Conductivity Astrid L.H.M.W. van Lier1, Alexander J. Raaijmakers1, David O. Brunner2, Dennis W.J. Klomp3, K. P. Pruessmann2, Jan J.W. Lagendijk1, Cornelis A.T. van den Berg1 1Radiotherapy, UMC Utrecht, Utrecht, Netherlands; 2Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland; 3Radiology, UMC Utrecht, Utrecht, Netherlands From basic EM (electromagnetic) theory we know that the wavelength, thus the propagating phase, depends on the permitivity and conductivity. Analysis, based on simulations, showed that local changes in the conductivity, have the largest effect on the propagating phase in the physiological range. We demonstrated that it is possible to measure the effect both in phantoms and in vivo, with results comparable to results of EM simulations. This new contrast mechanism might be useful for the detection of conducting malignancies, such as breast tumours. 2865. In Vivo Quantitative Conductivity Imaging Based on B1 Phase Information Tobias Voigt1, Ulrich Katscher2, Olaf Doessel1 1Institute of Biomedical Engineering, University of Karlsruhe, Karlsruhe, Germany; 2Philips Research Europe, Hamburg, Germany In this work, in vivo conductivity values of human tissue are obtained using standard MRI. Conductivity is a new and quantitative contrast for MRI. It can be obtained in 3D within 5 min by means of phase-based reconstruction presented in this abstract. Phase-based reconstruction is motivated analytically and validated in FDTD simulations and in in vivo experiments. 2866. Estimation of the Anisotropy of Electric Conductivity Via B1 Mapping Ulrich Katscher1, Tobias Voigt2, Christian Findeklee1 1Philips Research Europe, Hamburg, Germany; 2Institute of Biomedical Engineering, University of Karlsruhe, Karlsruhe, Germany Electric conductivity might be used as diagnostic information due to its ability to reflect the grade of tissue damage. In general, the conductivity is given by a tensor including anisotropic cases of conductivity, as can be found in vivo in tissue with preferred cell direction like muscles or nerves. Measuring conductivity, characterizing the underlying cell structure, might increase diagnostic information. The recently presented Electric Properties Tomography (EPT) is able to determine tissue conductivity in vivo by post-processing B1 maps. This study demonstrates the ability of EPT to estimate also the anisotropy of the conductivity using an electrically anisotropic phantom. Parallel Imaging Hall B Monday 14:00-16:00 Sumati Krishnan1, David Moratal2, Lei-Hou Hamilton3, Senthil Ramamurthy4, Marijn Eduard Brummer4 1Emory University, Atlanta, GA, United States; 22Universitat Politčcnica de Valčncia, Valencia, Spain; 3Georgia Institute of Technology, Atlanta, GA, United States; 4Emory University, Atlanta, GA, United States A well-known reconstruction method, based on error energy reduction [1], is adapted to sparsely sampled dynamic cardiac MRI. Inherent temporally band-limited properties of known static regions in the FOV, are used to recover additional resolution from information embedded in the acquired k-t samples. The algorithm converges as the error due to residual dynamic content in the static region is minimized. Reconstructions equivalent to direct matrix-inversion [2] are achieved with significantly reduced computational costs, while convergence properties are related to the sampling patterns. The proposed iterative method has potential applications for a variety of non-Cartesian grids as well as sparse-sampling patterns. 2868. Null Space Imaging: A Novel Gradient Encoding Strategy for Highly Efficient Parallel Imaging Leo Tam1, Jason Peter Stockmann1, Robert Todd Constable, 12 1Biomedical Engineering, Yale University, New Haven, CT, United States; 2Diagnostic Radiology & Neurosurgery, Yale University, New Haven, CT, United States Null Space Imaging (NSI) defines nonlinear encoding gradients to complement the spatial localization abilities of a parallel receiver array. To complement coil sensitivities, gradients should encode where coil sensitivities poorly distinguish signal. The singular value decomposition analyzes coil sensitivities to generate a complete basis set of vectors spanning the null space of sensitivities. By interpreting the orthogonal vectors in the null space as a complementary gradient set, NSI enables highly accelerated (R=16) parallel imaging as demonstrated by simulated spin echo experiments. NSI suggest complementary gradient design is a powerful concept for parallel imaging requiring only a limited set of receivers. 2869. GPU Accelerated Iterative SENSE Reconstruction of Radial Phase Encoded Whole-Heart MRI Thomas Sangild Sųrensen1, Claudia Prieto2, David Atkinson3, Michael Schacht Hansen4, Tobias Schaeffter2 1Aarhus Univeristy, Aarhus N, Denmark; 2King's College London; 3University College London; 4National Institutes of Health Isotropic whole-heart imaging has become an important protocol in simplifying cardiac MRI. The acquisition time can however be a prohibiting factor. To reduce acquisition times a 3D scheme combining Cartesian sampling in the readout direction with radial sampling in the phase encoding plane was recently suggested. It allows high undersampling factors in the phase encoding plane when obtaining data with a 32-channel coil array and employing non-Cartesian iterative SENSE for reconstruction. Unfortunately this reconstruction is a time consuming process. We demonstrate however that the reconstruction time can be brought to a clinically acceptable level using commodity graphics hardware (GPUs). 2870. Calibrationless Parallel Imaging Reconstruction by Structured Low-Rank Matrix Completion Michael Lustig1,2, Michael Elad3, John Mark Pauly2 1Electrical Engineering and Computer Science, University of California Berkeley, Berkeley, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States; 3Computer Science, Technion IIT, Haifa, Israel A new method for parallel imaging that requires no special autocalibration lines or calibration scans is presented. Instead, the method jointly calibrates, and synthesizes missing data from the entire acquired k-space. The proposed method is based on low-rank matrix completion, which is an extension of the compressed sensing theory to matrices. It is implemented by iterative singular value thresholding. The method can be used to reconstruct undersampled data, to generate calibration data for GRAPPA-like methods, or just to improve calibration when the calibration area is too small. 2871. Context Based GRAPPA Reconstruction Using a Small Kernel Berkay Kanberoglu1, Lina J. Karam1, Josef P. Debbins2 1Electrical Engineering, Arizona State University, Tempe, AZ, United States; 2Keller Center for Imaging Innovation, Barrow Neurological Institute, Phoenix, AZ, United States For GRAPPA reconstruction, large kernel sizes can be disadvantageous in some cases due to the large number of GRAPPA coefficients. A system like this needs a large number of equations to construct an over-determined system. Small kernel sizes can be advantageous when there is a small number of equations. Proposed algorithm employs a small kernel size and a clustering method to produce more than one set of GRAPPA weights within a slice. 2872. Sinusoidal Perturbations Improve the Noise Behavior in Parallel EPI Maximilian Haeberlin1, Bertram Wilm1, Christoph Barmet1, Sebastian Kozerke1, Georgios Katsikatsos1, Klaas Paul Pruessmann1 1Department of Electrical Engineering, ETH Zurich, Zurich, Switzerland Perturbing EPI phase encoding lines in a sinusoidal fashion improves the g-factor map for SENSE reconstruction. Concurrent field monitoring ensures artifact-free reconstruction for 3-fold undersampled data. Julien Sénégas1, Martin Uecker2 1Philips Research Europe, Hamburg, Germany; 2Biomedizinische NMR Forschungs GmbH, Göttingen, Germany Recently, iterative joint estimation algorithms have been proposed to reconstruct aliasing free images and coil sensitivities in a single step from self-calibrating sampling trajectories such as Cartesian with variable density. Due to the non-linearity of the reconstruction method, their behavior with respect to noise amplification is more difficult to predict. In this work, we extend the non-linear inversion algorithm (NLINV) by incorporating the noise covariance of the coil array in the minimization function and by applying additional regularization for the coil sensitivities, both with the aim of improving the SNR of the reconstructed image. We present detailed results on the noise amplification properties of this joint reconstruction scheme and evaluate the proposed algorithm in vivo. 2874. Optimally Regularized GRAPPA/GROWL with Experimental Verifications Wei Lin1, Feng Huang1, Hu Cheng2, Yu Li1, Arne Reykowski1 1Advanced Concepts Development, Invivo Corporation, Philips Healthcare, Gainesville, FL, United States; 2Indiana University, Bloomington, IN, United States The performance of GRAPPA-based parallel imaging methods can suffer when the size of the auto-calibration signal (ACS) region becomes small. Based on an analysis of condition number for GRAPPA calibration equation, an optimal Tikhonov regularization factor is proposed to improve the quality of image reconstruction. Alternatively, an optimal amount of noise can be added to the ACS data to stabilize the system. The technique was applied to both GRAPPA and GRAPPA operator for wider radial bands (GROWL), a self-calibrated radial parallel imaging methods. Results show that minimal reconstruction errors are always obtained with the proposed automatic regularization scheme. Eric Y. Pierre1, Nicole Seiberlich2, Stephen Yutzy1, Vikas Gulani2, Felix Breuer3, Mark Griswold2 1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; 2Departments of Radiology, Case Western Reserve University, Cleveland, OH, United States; 3Research Center Magnetic Resonance Bavaria e.V., Würzburg, Germany The ABSINTHE technique has been shown to allow better GRAPPA reconstructions at high undersampling factors by sparsifying the undersampled image to reconstruct. This study seeks to further increase the effectiveness of ABSINTHE by improving the PCA approximation which generates this sparse image. After a first standard ABSINTHE estimation, iterative ABSINTHE uses fully-sampled eigenvectors to generate an even sparser representation of the undersampled data. The efficacy of this technique for simulated data and longitudinal simulations is demonstrated, and an improved image quality is shown for iterative ABSINTHE in comparison to the standard ABSINTHE and GRAPPA techniques. 2876. Tailored 3D Random Sampling Patterns for Nonlinear Parallel Imaging Florian Knoll1, Christian Clason2, Rudolf Stollberger1 1Institute of Medical Engineering, Graz University of Technology, Graz, Austria; 2Institute for Mathematics and Scientific Computing, University of Graz, Graz, Austria The idea of randomized 3D Cartesian subsampling was proposed within the framework of compressed sensing. The optimal design of these sampling patterns is an open problem, especially the determination of the correct ratio of low to high frequency sample points. The goal of this work is to show that it is possible to construct an adapted random sampling pattern by using measured k-space data as a reference, which automatically ensures an appropriate distribution of sample points for different types of scans. In this work, these sampling patterns were used in combination with regularized nonlinear inversion for parallel imaging. This allows the use of very high acceleration factors while still yielding images with excellent image quality. 2877. Fast Non-Iterative JSENSE: From Minutes to a Few Seconds Feng Huang1, Wei Lin1, Yu Li1, Arne Reykowski1 1Invivo Corporation, Gainesville, FL, United States It has been shown that joint image reconstruction and sensitivity estimation in SENSE (JSENSE) can improve image reconstruction quality when acceleration factor is high. However, existing methods for JSENSE need long reconstruction time and/or optimal termination condition, which have hindered its clinical applicability. In this work, a fast non-iterative JSENSE technique, based on pseudo full k-space, is proposed to improve the clinical applicability of JSENSE. Using the proposed method, the computation time for sensitivity maps could be reduced from minutes to a few seconds without degrading the image quality. 2878. Parallel Imaging Using a 3D Stack-Of-Rings Trajectory Holden H. Wu1,2, Michael Lustig2,3, Dwight G. Nishimura2 1Cardiovascular Medicine, Stanford University, Stanford, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States; 3Electrical Engineering and Computer Science, University of California at Berkeley, Berkeley, CA, United States We present an efficient parallel imaging strategy for the 3D stack-of-rings non-Cartesian trajectory to further enhance its flexible trade-offs between image quality and scan time. Due to its distinct geometry, parallel imaging reconstruction for the 3D stack-of-rings trajectory can be decomposed directly into a series of 2D Cartesian sub-problems, which can be solved very efficiently. Experimental results demonstrate that a 2-fold reduction in scan time can be achieved on top of the 2-fold speedup already offered by the rings (compared to Cartesian encoding). Our approach combines the acceleration from both non-Cartesian sampling and parallel imaging in an efficient and easily deployable algorithm. Philip James Beatty1, James H. Holmes2, Shaorong Chang, Ersin Bayram, Jean H. Brittain3, Scott B. Reeder4 1Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States; 2Applied Science Laboratory, GE Healthcare, Waukesha, WI, United States; 3Applied Science Laboratory, GE Healthcare, Madison, WI, United States; 4Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, WI, United States Compared to coil-by-coil reconstructions, Direct Virtual Coil (DVC) parallel imaging reconstructions improve computational efficiency for high channel count coil arrays by only synthesizing unacquired data for one virtual coil instead of synthesizing a separate dataset for each physical coil. In this study, image quality is compared between coil-by-coil and DVC parallel imaging reconstructions in the context of contrast-enhanced liver imaging. Results showed no significant difference in the image quality achieved by the two reconstruction methods. 2880. Towards a Geometry Factor for Projection Imaging with Non-Linear Gradient Fields Jason P. Stockmann1, Gigi Galiana2, Robert Todd Constable3 1Biomedical Engineering, Yale University, New Haven, CT, United States; 2Diagnostic Radiology, Yale University, New Haven, CT, United States; 3Diagnostic Radiology, Neurosurgery, and Biomedical Engineering, Yale University, New Haven, CT, United States Conventional parallel imaging performance is assessed either by computing the analytical geometry factor or, if necessary, comparing the SNRs of fully-sampled and undersampled Monte Carlo reconstructions. The empirical g-factor is unsuitable, however, for methods such as O-Space imaging in which non-linear gradients are used to obtain projections of the object. Since O-Space point spread functions are highly variable with position, the g-factor must be corrected for voxel-size in order to distinguish intra-voxel blurring from true noise amplification. This work shows the limited utility of uncorrected empirical g-factors for O-Space imaging and discusses how to compute the PSF for this class of non-linear projection imaging methods. 2881. Selection of Image Support Region and of an Improved Regularization for Non-Cartesian SENSE Yoon Chung Kim1, Jeffrey Fessler2, Douglas Noll1 1Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States; 2Electrical Engineering, University of Michigan, Ann Arbor, MI, United States Even though non-Cartesian parallel imaging has demonstrated increasing potential for an acquisition tool in MRI, there are still drawbacks such as reduced SNR and incomplete suppression of the undersampling or aliasing artifact. In suppressing such artifacts, the selection of image support, specifying a reconstruction region of interest is an important factor, due to the complex aliasing pattern associated with undersampling. Proper selection of image support can improve the conditioning of the reconstruction by constraining regions that are known to be zero. In this study, we investigate how the selection of image support region affects the performance of non-Cartesian SENSE reconstruction applied to undersampled spiral k-space data. Considering a potential effect of the sharp edges of a conventional mask on aliasing artifact, we also applied a smoothed mask through an additional regularized term to give smoothness to the mask edges. We tested our hypotheses on masking effects with the simulation and in-vivo human data and our results show that using a moderate size of mask can improve the image quality and the smoothing the mask is effective in suppressing aliasing artifact. Functional MRI result also indicates that softening function further increases the number of activated pixels and tSNR, and reduces image domain error. 2882. Variable-Density Parallel Imaging with Partially Localized Coil Sensitivities Tolga Ēukur1, Juan Santos1, John Pauly1, Dwight Nishimura1 1Department of Electrical Engineering, Stanford University, Stanford, CA, United States PILS is a very fast reconstruction method for both Cartesian and non-Cartesian sampling; however, it can suffer from residual aliasing artifacts when coupled with variable-density acquisitions. In this work, we propose an improved variable-FOV method that suppresses the aliasing artifacts, while optimally utilizing the densely sampled low-spatial-frequency data. Individual coil images are then linearly combined using data-driven sensitivity estimates. In vivo comparisons with PILS and SENSE are provided. 2883. Synthetic Target Combined with PILS (ST-PILS) for Improving SNR in Parallel Imaging Meihan Wang1, Weitian Chen2, Michael Salerno1, Peng Hu3, Christopher M. Kramer1, Craig Meyer1 1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States; 2GE; 3Beth Israel Deaconess Medical Center, The abstract introduces a novel rapid reconstruction algorithm called ST(Synthetic Target)-PILS. It improves the original Synthetic Target method by achieving a higher SNR. We also studied reconstruction speed comparing to coil-by-coil reconstruction. 2884. Iterative IIR GRAPPA: A Novel Improved Method for Parallel MRI Kaiyu Zheng1, Wendy Ni1, Jingxin Zhang2 1Monash Unversity; 2Department of Electrical and Computer Systems Engineering, Monash University, Clayton, VIC 3800, Australia GRAPPA proves to be an effective constrained parallel MRI method. However, it does not exploit the acqired data to the utmost.In our investigation to produce a superior parallel Magnetic Resonance Imaging (MRI) reconstruction technique, we propose the novel method of Infinite Impulse Response Iterative GRAPPA (IIR iGRAPPA). This method uses both acquired and reconstructed data points to iteratively interpolate downsampled k-space data, achieving excellent reconstruction quality without the need to acquire much additional data for calibration purposes. Experimental results clearly demonstrate the superiority of the proposed method over the conventional GRAPPA method. 2885. Applying Parallel Imaging for SNR Enhancement Daniel Stäb1, Christian Ritter1, Dietbert Hahn1, Herbert Köstler1 1Institute of Radiology, University of Wuerzburg, Wuerzburg, Bavaria, Germany Typically in fast MRI, the measurements are carried out using a high readout bandwidth, leading to a generally low SNR. In this work undersampling k-space, while maintaining the image acquisition time is proposed. Consequently, TR and the signal acquisition time can be raised and the SNR is increased. For image reconstruction, parallel imaging techniques are utilized. As the SNR gain is considerably influenced by the geometry factor crucial investigations are required. g-factors are minimized by homogeneously distributing the phase encoding steps over k-space. Thus, in terms of SNR, the use of additional reference scans or techniques like TGRAPPA, TSENSE and Auto-SENSE is advantageous. 2886. Noise Weighted T2*-IDEAL Reconstruction for Non-Uniformly Under-Sampled k-Space Acquisitions Curtis Nathan Wiens1, Shawn Joseph Kisch2, Catherine D. G. Hines3, Huanzhou Yu4, Angel R. Pineda5, Philip M. Robson6, Jean H. Brittain7, Scott B. Reeder, 38, Charles A. McKenzie1,2 1Department of Physics and Astronomy, University of Western Ontario, London, Ont, Canada; 2Department of Medical Biophysics, University of Western Ontario, London, Ont, Canada; 3Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; 4Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States; 5Department of Mathematics, California State University, Fullerton, CA, United States; 6Department of Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States; 7Applied Science Laboratory, GE Healthcare, Madison, WI, United States; 8Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States Using different undersampling patterns for the non-calibration and calibration echoes has been shown to improve SNR per unit time of Parallel Imaging accelerated IDEAL reconstructions by up to 40%. The different acceleration factors and k-space undersampling patterns result in different noise enhancement in the non-calibration and calibration echoes. In this work the T2*-IDEAL reconstruction is modified to include noise weighting and demonstrate that SNR improves with the modified reconstruction. For 14.2 fold accelerated phantom data, an 11.9% increase in mean SNR for all phantoms and a maximum 27% increase in SNR over a single phantom was measured. 2887. Three-Dimensionally Accelerated Radial Parallel MRI with a 32-Channel Coil System Olaf Dietrich1, Maria Suttner1, Maximilian F. Reiser1 1Josef Lissner Laboratory for Biomedical Imaging, Department of Clinical Radiology, LMU Ludwig Maximilian University of Munich, Munich, Germany Established parallel-imaging techniques include the one-dimensional or two-dimensional acceleration of the data acquisition with Cartesian or non-Cartesian trajectories. However, state-of-the-art receiver coil arrays with 32 and more coil elements that are distributed approximately uniformly in space should also enable a three-dimensional parallel-imaging acceleration, i.e. simultaneous sparse sampling in all three k-space directions. The purpose of this study was to demonstrate three-dimensional parallel-imaging acceleration with high acceleration factors up to 32 based on a three-dimensional radial gradient-echo sequence. 2888. A Rapid Self-Calibrating Radial GRAPPA Method Using Kernel Coefficient Interpolation Noel C. Codella1, Pascal Spincemaille2, Martin Prince2, Yi Wang2 1Physiology, Cornell Weill Medical College, New York, NY, United States; 2Radiology, Cornell Weill Medical College This work proposes a rapid self-calibrating radial GRAPPA method that eliminates the need to change domains, calculate sensitivity maps, generate synthetic calibration data, or perform extra gridding operations before the derivation of the GRAPPA kernels. 2889. Zoomed GRAPPA (ZOOPPA) for Functional MRI Robin Martin Heidemann1, Dimo Ivanov1, Robert Trampel1, Fabrizio Fasano2, Josef Pfeuffer3, Robert Turner1 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; 2Fondazione Santa Lucia, Rome, Italy; 3Siemens Healthcare Sector, Erlangen, Germany The increased SNR of ultra-high field MR scanners permits improved resolution of fMRI acquisitions. Unfortunately, both high field and high resolution amplify artifacts such as geometric distortions and blurring. Parallel imaging and zoomed imaging can each mitigate these effects. However, highly accelerated parallel imaging is affected by residual artifacts, while excessive zooming sacrifices spatial coverage. A robust combination of both methods is optimized here (Zoomed imaging with GRAPPA - ZOOPPA) to provide high quality single-shot EPI human brain images with reasonable coverage and an isotropic resolution of 0.65 mm. 2890. Conjugate Gradient PINOT Reconstruction with a Fast Initial Estimate Lei Hou Hamilton1, Benjamin Russell Hamilton1, David Moratal2, Senthil Ramamurthy3, Marijn Brummer3 1School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, United States; 2Universitat Politčcnica de Valčncia, Valčncia, Spain; 3Emory University, United States PINOT (Parallel Imaging and NOquist in Tandem), a fast imaging method combining SPACE-RIP and Noquist, favorably preserves edge detail at a cost of increased SNR. PINOT involves a large matrix inversion for each read-out coordinate to combine data from all frames and coils. We use iterative conjugate gradient (CG) to reduce this computational burden. An initial estimate based on the projection matrixs structure allows CG-PINOT to converge quickly. We simulate this CG-initiated PINOT (CGi-PINOT) with phantom and in vivo studies, showing it provides better reconstructed image quality with an order of magnitude less time than direct inversion PINOT. 2891. Computationally Rapid Method for Estimating SNR of Arbitrary Parallel MRI Reconstructions Curtis Nathan Wiens1, Shawn Joseph Kisch2, Jacob David Willig-Onwuachi3, Charles A. McKenzie1,2 1Department of Physics and Astronomy, University of Western Ontario, London, Ontario, Canada; 2Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 3Department of Physics, Grinnell College, Grinnell, IA, United States Existing approaches for measuring parallel MRI SNR are limited because they are not applicable to all reconstructions, require significant computation time or need repeated image acquisitions. A new SNR estimation approach is proposed that is a hybrid of the two acquisition and multiple pseudo replica methods. The difference of two pseudo-images is used to estimate the noise in the acquisition. This gives a computationally rapid method of measuring SNR from a single acquisition. SNR maps using the two pseudo-image method were compared to pseudo-replica. All tests of the proposed method were on average within ±1.75%. Philip James Beatty1, Shaorong Chang2, Ersin Bayram2, Ananth Madhuranthakam3, Huanzhou Yu1, Scott B. Reeder4, Jean H. Brittain5 1Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States; 2GE Healthcare, Waukesha, WI, United States; 3Applied Science Laboratory, GE Healthcare, Boston, MA, United States; 4Departments of Radiology and Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 5Applied Science Laboratory, GE Healthcare, Madison, WI, United States Setting the phase of the virtual coil in the Direct Virtual Coil (DVC) reconstruction technique is both critical to achieving a high quality reconstruction and challenging, especially with high channel count arrays. In this work, a region growing approach to setting the virtual coil phase is described and evaluated in the context of the DVC technique. We demonstrate that the approach is able to generate sensible virtual coil phase even in challenging situations. 2893. Random Phase Modulation of Spatial Aliasing in Temporal Domain for Dynamic MRI Yu Li1, Feng Huang1, Wei Lin1, Arne Reykowski1 1Advanced Concept Development, Invivo Diagnostic Imaging, Gainesville, FL, United States In this study, we propose a new k-t space sampling trajectory for parallel dynamic MRI. This method applies random phase modulation to the spatial aliasing of images in temporal domain. As a result, the spatial aliasing induced by k-space undersampling at every time frame has a noise pattern in temporal dimension. By applying a temporal constraint that can be known from the priori knowledge of dynamic MRI data, the noise-like aliasing can be easily removed. This work uses the fMRI and cardiac imaging applications as examples to demonstrate the feasibility of the proposed method. 2894. Rapid 3D Parallel Imaging of Non-Cartesian Data Nicholas Ryan Zwart1, James Grant Pipe1 1Keller Center for Imaging Innovation, Barrow Neurological Institute, Phoenix, AZ, United States A 3D parallel imaging reconstruction technique is presented. This technique is a coil sensitivity based method used for reconstructing undersampled arbitrary 3D k-space trajectories. Iterations enforce receive b1-field and sampled data consistency without degridding/gridding operations improving the computational speed compared to similar reconstruction methods. The 3D trajectory used is Spiral Projection Imaging. 2895. Improvement of Quantitative MRI Using Radial GRAPPA in Conjunction with IR-TrueFISP Martin Kunth1, Nicole Seiberlich2, Philipp Ehses1, Vikas Gulani2, Mark Griswold2 1Experimentelle Physik V, Universitaet Wuerzburg, Wuerzburg, Germany; 2Radiology, Case Western Reserve University, Cleveland, OH, United States While the use of IR-TrueFISP to quantify the relaxation parameters T1 and T2 and the proton density M0 has been demonstrated, these values can be difficult to quantify in species with fast relaxation because the first points along the relaxation curve are hard to assess. This abstract explores the use of the recently proposed technique through-time radial GRAPPA to reconstruct highly undersampled radial images acquired along the relaxation curve. In this way, the first few points after the inversion can be assessed and the relaxation parameters more accurately quantified. 2896. Maxwell's Equation Tailored Reverse Method of Obtaining Coil Sensitivity for Parallel MRI Jin Jin1, Feng Liu1, Yu Li1, Ewald Weber1, Stuart Crozier1 1ITEE, The University of Queensland, St Lucia, Queensland, Australia A new method is proposed to obtain noise-free RF coil sensitivity maps. This is highly desirable, considering the fact that the sensitivity encoding (SENSE) method imposes ultimate dependence of successful full FOV image reconstruction on the correct sensitivity map of each individual coil. The proposed method differs from traditional methods in that, instead of refining the measured sensitivity maps by means of numerical approximation and/or extrapolation, it is based on physics of electromagnetics, parameterization and optimization algorithms. Preliminary simulations show substantial improvement in sensitivity maps constructed by proposed method compared to traditional polynomial fitting method and consequently in reconstructed images. 2897. Sub-Sampling Parallel MRI with Unipolar Matrix Decoding Doron Kwiat1 1DK Computer College, Tel-Aviv, Israel A method is proposed of parallel array scan, where signals from coils are combined by a summing multiplexer and decoded by unipolar matrix inversion is suggested, which reduces acquisition channels to a single pre-amp and A/D. The results would be, an independent individual separated signals as if acquired through multiple acquisition channels, and yet at a total acquisition time similar to acquisition time of multiple channels, Background In a standard parallel array technology, N coils simultaneously cover N FOVs by reading N k-space lines simultaneously over N independent data sampling channels. These k-space lines are phase weighted to maximize SNR and then FT converted to N independent images with an increased SNR[1]. In current accelerated PI techniques, some of K-space lines are skipped physically, and are replaced by virtual k-space substitutes using preumed spatial sensitivities of the coils in the PE direction [2-5]. Based on the method described recently [6,7] a new scanning procedure is described here. The Method 1.Have all coils be connected through a single summing multiplexer unit (MUX) which allows, at our discretion, selecting N-1 coils to be actively connected while a single coil is deactivated electronically, to a single summing common output (SCO). Let the summed signal from these N-1 coils be sampled by the single acquisition channel (ACQ) having a single pre-amp and single A/D. 2.Scan 1/Nth of the total k-space lines while having N-1 coils actively connected to the ACQ by the MUX unit. Repeat the above scan procedure over another 1/Nth part of k-space, this time with another set of N-1 coils actively connected, and 1 coil deactivated. Keep these scan procedures N times, until all k-space lines were acquired over all N possible permutations of selections of N-1 coils out of N. 3. There are now exactly N summed acquisitions at our hands. Using an inverse of a unipolar matrix, these can be now decoded back to the original individual k-space lines Non-Cartesian Imaging Methods Hall B Tuesday 13:30-15:30 2898. 3D Dual VENC PCMRA Using Spiral Projection Imaging Nicholas Ryan Zwart1, James Grant Pipe1 1Keller Center for Imaging Innovation, Barrow Neurological Institute, Phoenix, AZ, United States This work focuses on the reduction of scan time required by the phase-contrast MRA technique. The proposed method consists of a 3D variable density spiral projection imaging trajectory (SPI) combined with a dual velocity encoding technique. SPI is a rapid imaging technique that improves acquisition time through the intrinsic efficiency of spirals and through undersampling. The dual-VENC method improves SNR by allowing low-VENC (high SNR) data to be reconstructed without phase aliasing of the velocity measurements. Pascal Spincemaille1, Beatriu Reig1, Martin R. Prince1, Yi Wang1 1Radiology, Weill Cornell Medical College, New York, NY, United States High temporal resolution dynamic contrast enhanced liver imaging is achieved using a novel k-space sampling method that samples the phase and slice encoding plane along true radial trajectories with an angularly varying field-of-view and resolution. Combined with an adapted golden ratio view order, it eliminates the need for accurate bolus timing and allows the retrospective selection of the optimal arterial enhancement for the detection and characterization of liver lesions. 2900. Magnetization-Prepared Shells with Integrated RadiaL and Spirals Yunhong Shu1, Matt A. Bernstein1 1Department of Radiology, Mayo Clinic, Rochester, MN, United States In this work, we demonstrate the initial feasibility of combining the SWIRLS trajectory with the MP-RAGE acquisition for volumetric T1-weighted brain imaging. The SWIRLS trajectory uses one continuous interleave to cover the surface of a spherical shell from pole-to-pole, which offer more flexibility for magnetization prepared (MP) design than the traditional shells trajectory. Meanwhile, it also shares the advantages of shells trajectory, including optimizing the contrast between WM and GM with reduced scan time. 2901. High-Field MRI for Non-Invasive Preclinical Imaging in Free-Breathing Mice Prachi Pandit1,2, Yi Qi2, Kevin F. King3, G A. Johnson1,2 1Biomedical Engineering, Duke University, Durham, NC, United States; 2Center for In Vivo Microscopy, Duke University, Durham, NC, United States; 3GE Healthcare, Waukesha, WI, United States The requirements for preclinical cancer imaging are high spatial resolution, good soft tissue differentiation, excellent motion immunity, and fast and non-invasive imaging to enable high-throughput, longitudinal studies. Here we describe a PROPELLER-based technique, which with its unique data acquisition and reconstruction overcomes the adverse effects of physiological motion, allows for rapid setup and acquisition and provides excellent tissue contrast. Hardware optimization as well as sequence modification enable us to obtain heavily T2-weighted images at high-fields in tumor-bearing mice with in-plane resolution of 117μm and slice thickness of 1mm. Multi-slice datasets covering the entire thorax and abdomen are acquired in ~40 minutes. 2902. ZOOM-PROPELLER-EPI: Non-Axial Imaging at Small FOV with PROPELLER-EPI Hing-Chiu Chang1,2, Chun-Jung Juan3, Yi-Jui Liu4, Chao-Chun Lin2,5, Hao Shen6, Tzu-Chao Chuang7, Hsiao-Wen Chung2 1Applied Science Laboratory, GE Healthcare Taiwan, Taipei, Taiwan; 2Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; 3Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan; 4Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan; 5Department of Radiology, China Medical University Hospital, Taichung, Taiwan; 6Applied Science Laboratory, GE Healthcare, Beijing, China; 7Electrical Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan Current implementation of PROPELLER-EPI exhibits difficulty in small FOV or non-axial acquisition due to the aliasing artifact along the phase-encoding direction of each blade. In this work, we propose a ZOOM-PROPELLER-EPI technique, which combines the reducing-FOV (rFOV) EPI to obtain sagittal images with a small FOV. We combined PROPELLER-EPI with three types of rFOV EPI technique based on inner volume excitation, both phantom and in vivo results demonstrated effectiveness of ZOOM-PROPELLER-EPI. The proposed method may find applications in non-axial high-resolution scans such as diffusion-weighted imaging of the cerebellum. Fat-Water Separation Hall B Wednesday 13:30-15:30 2903. Quantification of Fatty Acid Compositions Using MR-Imaging and Spectroscopy at 3 T Pernilla Peterson1, Håkan Brorson2, Sven Månsson1 1Medical Radiation Physics, Lund University, Malmö, Sweden; 2Plastic and Reconstructive Surgery, Lund University, Malmö, Sweden This phantom study aims at investigating the potential of multi-echo imaging and spectroscopy to quantify the fraction unsaturated fatty acids (UF) and compare the results against known values. Six oil phantoms (UFs: 8%-92%) were measured in a 3T Siemens scanner with PRESS-localized spectroscopy and multi gradient echo sequences. Two fat resonances were separated from the acquired spectra using jMRUI and from multi-echo images using a linear least-squares approach. Both methods successfully quantified UFs with slopes/intercepts 0.886/3.80% and 0.956/11.3% for imaging and spectroscopy, respectively. This experiment successfully demonstrates the ability of multi-echo imaging and spectroscopy to evaluate fatty acid compositions. 2904. Bipolar 3D-FSE-IDEAL: Fast Acquisition of Volumetric T2-Weighted Fat and Water Ananth J. Madhuranthakam1, Huanzhou Yu2, Ann Shimakawa2, Martin P. Smith3,4, Scott B. Reeder5, Neil M. Rofsky3,4, Charles A. McKenzie6, Jean H. Brittain7 1MR Applied Science Lab, GE Healthcare, Boston, MA, United States; 2MR Applied Science Lab, GE Healthcare, Menlo Park, CA, United States; 3Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 4Harvard Medical School, Boston, MA, United States; 5Radiology, Medical Physics, Biomedical Engineering and Medicine, University of Wisconsin, Madison, WI, United States; 6Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 7MR Applied Science Lab, GE Healthcare, Madison, WI, United States In this work, a bipolar acquisition with 3D-FSE-IDEAL is presented that reduces total scan time by acquiring all three images required for IDEAL processing in a single repetition. To eliminate phase errors that arise from alternating polarities of the readout gradients, a novel 2D phase correction method was implemented. High-resolution 3D T2-weighted images with uniform fat-water separation are demonstrated in breast and knee applications with less than 5-minute acquisition times. 2905. MR Water/Fat Separation Improves Optical Breast Imaging Colin Morehouse Carpenter1, Shudong Jiang2, Brian William Pogue2, Keith David Paulsen2 1Radiation Oncology, Stanford University School of Medicine, Stanford, CA, United States; 2Thayer School of Engineering at Dartmouth, Hanover, NH, United States IDEAL water/fat separation was used to improve hemoglobin quantification of MR-guided optical imaging. This technique is shown to reduce the cross-talk between oxyhemoglobin and water, caused by the spectral similarity of these tissue constituents in the near-infrared. It is demonstrated in gelatin phantoms that this approach reduces error in oxyhemoglobin by 70% on average for several cases. This finding has significant benefit for optical breast imaging, as the improved quantification provided by the MR water image can be leveraged to reduce the number of wavelengths in the optical data acquisition and thus increase temporal resolution. 2906. Flexible and Efficient Data Acquisition Technique for 3D-FSE-IDEAL Ananth J. Madhuranthakam1, Huanzhou Yu2, Ann Shimakawa2, Martin P. Smith3,4, Scott B. Reeder5, Neil M. Rofsky3,4, Charles A. McKenzie6, Jean H. Brittain7 1MR Applied Science Lab, GE Healthcare, Boston, MA, United States; 2MR Applied Science Lab, GE Healthcare, Menlo Park, CA, United States; 3Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 4Harvard Medical School, Boston, MA, United States; 5Radiology, Medical Physics, Biomedical Engineering and Medicine, University of Wisconsin, Madison, WI, United States; 6Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 7MR Applied Science Lab, GE Healthcare, Madison, WI, United States FSE-IDEAL requires at least three echoes for uniform fat-water separation. The three echoes are commonly acquired in multiple repetitions. Recently, methods have been proposed to reduce total scan time by acquiring multiple gradient echoes in a repetition. Acquisition of a fourth echo increases the flexibility for choosing the gradient echo spacing to enable higher resolution acquisitions in reasonable scan times. We test this hypothesis in phantom studies and show a new data acquisition approach to acquire high-resolution 3D T2-weighted fat-water separated images of the breasts and knee with higher SNR in reduced scan times. 2907. Single-Image Water/fat Separation Johan Berglund1, Håkan Ahlström1, Lars Johansson1, Joel Kullberg1 1Department of radiology, Uppsala university, Uppsala, Sweden A post processing method is presented, that separates water and fat from a single complex image. Initially, each voxel is assumed to be either water- or fat dominant, giving two alternative field heterogeneity phasors. Spatial smoothness of the field map is imposed by formulating an optimization problem, which is solved approximately using a multiscale belief propagation algorithm. Smoothing of the field map relaxes the initial assumption of water- or fat dominance. Water and fat signals are found analytically in each voxel. Initial results from abdomen and whole-body datasets at 1.5 T and 3.0 T were found promising. Venkata Veerendranadh Chebrolu1, Huanzhou Yu2, Angel R. Pineda3, Charles A. McKenzie4, Jean H. Brittain5, Scott B. Reeder, 1,6 1Biomedical Engineering, University of Wisconsin Madison, Madison, WI, United States; 2Applied Science Laboratory, GE Healthcare,, Menlo Park,, CA, United States; 3Department of Mathematics, California State University, Fullerton, CA, United States; 4Department of Medical Biophysics, University of Western Ontario,, London, Ontario; 5Applied Science Laboratory, GE Healthcare,, Madison, WI, United States; 6Radiology, University of Wisconsin Madison, Madison, WI, United States The noise analysis for chemical shift based decomposition of water and fat was theoretically computed for methods that account for single and dual exponential T2* correction along with spectral modeling of fat. The CramerRao bound (CRB) formulation was used to study the variance of the estimates of the water and fat images by computing the maximum effective number of signals averaged (NSA) for a range of echo combinations and fat-water ratios. These theoretical results predict that noise performance degrades with independent estimation of T2* of water and fat. 2909. Lipid Suppresion Using Spectral Editing of Fast Spin Echo Trains Andrew J. Wheaton1, James B. Murdoch1, Robert Anderson1 1Toshiba Medical Research Inst. USA, Mayfield, OH, United States The REFUSAL [REFocusing Used to Selectively Attenuate Lipids] technique incorporates a spectrally-selective editing pulse in the position of the first refocus pulse of an rf echo train. By fully refocusing water and while minimally refocusing lipid resonances, fat signal is refused from evolving in the rf echo train. The phase-modulated REFUSAL pulse is designed for B1-robustness with a sharp transition between fat and water for good δB0-insensitivity. REFUSAL produces images with uniform, T1-insensitive fat suppression over a wide range of B1. 2910. PASTA++: B1- And T1-Robust Fat Suppression at 3T Andrew J. Wheaton1, Robert Anderson1 1Toshiba Medical Research Inst. USA, Mayfield, OH, United States PASTA uses a combination of low rf excitation bandwidth and alternate excitation and refocus slice selection gradient polarities to remove fat signal via chemical shift. PASTA++ is an improved version of PASTA designed for 3T. Using 3T-tailored rf pulse choices and irregular echo spacing, PASTA++ can be included in an fast spin-echo readout with short echo spacing. PASTA++ delivers high SNR images with uniform fat suppression even in the presence of B0 inhomogeneity. Since PASTA++ does not use a prepulse, it delivers fat suppression immune to B1- and T1-variation without increasing SAR. 2911. A Joint Estimation Method for Two-Point Water/fat Imaging with Regularized Field Map Diego Hernando1, Peter Kellman2, Zhi-Pei Liang1 1Electrical and Computer Engineering, University of Illinois, Urbana, IL, United States; 2National Institutes of Health, Bethesda, MD, United States Two-point methods for water/fat imaging are attractive because of their moderate acquisition time. In this work, we adapt a previously proposed joint estimation approach for two-point acquisitions and demonstrate its performance using simulations, phantom results and in vivo data. The proposed method, based on a regularized formulation and a graph cut solution, results in good noise properties and the ability to handle large B0 field inhomogeneities. Kuan J. Lee1, Benjamin Zahneisen1, Jürgen Hennig1, Weigel Matthias1, Jochen Leupold1 1Medical Physics, University Hospital Freiburg, Freiburg, Baden-Württemberg, Germany Multiplex RARE is a new sequence in which multiple slices are simultaneously excited and refocused in a spin-echo train. The echo trains are interleaved in such a way that CPMG conditions are fulfilled at all times, and signals from slices can be separated, preventing aliasing. This work demonstrates how the sequence may be used in a novel fat-water Dixon method, which enables fast volume coverage of multiple, simultaneously excited slices. The technique is demonstrated in-vivo and compared with fTED, another fast Dixon method. 2913. Cardiac Imaging with Chemical Shift Based Water-Fat Separation at 3T Karl Kristopher Vigen1, Chris J. Francois1, Ann Shimakawa2, Huanzhou Yu2, Scott K. Nagle1, Mark L. Schiebler1, Scott B. Reeder1,3 1Radiology, University of Wisconsin-Madison, Madison, WI, United States; 2Applied Science Lab, GE Healthcare, Menlo Park, CA, United States; 3Medical Physics, University of Wisconsin-Madison, Madison, WI, United States Chemical shift based water-fat separation methods have recently been demonstrated for 1.5T cardiac imaging. Higher field strengths (most notably 3T) are increasingly used in cardiac imaging, but water-fat separation techniques can be challenging due to proportionately higher resonance frequency offsets. An interleaved multi-echo sequence using the IDEAL water-fat method has been developed for cardiac imaging at 3T and applied to the evaluation of delayed-enhancement imaging and other fat-containing pathologies. 2914. Feasibility of T2* Estimation with Chemical Shift-Based Water-Fat Separated Cardiac Imaging Karl Kristopher Vigen1, Huanzhou Yu2, Chris J. Francois1, Ann Shimakawa2, Scott B. Reeder1,3 1Radiology, University of Wisconsin-Madison, Madison, WI, United States; 2Applied Science Lab, GE Healthcare, Menlo Park, CA, United States; 3Medical Physics, University of Wisconsin-Madison, Madison, WI, United States T2* mapping has previously been investigated in cardiac imaging for iron overload assessment and detection of myocardial BOLD effects. Advanced T2* measurement techniques have been previously demonstrated with chemical shift-based fat-water separation techniques in applications such as iron- and fat-content measurement in the liver, and chemical shift-based fat-water decomposition methods have been used to separate fat and water in cardiac imaging. In this work, the feasibility of T2* mapping with chemical shift-based fat-water decomposition in cardiac imaging is demonstrated. Tania Buehler1, Nicolas Ramseier1, Juergen Machann2, Nina Schwenzer2, Chris Boesch1 1Dept. of Clinical Research, University of Bern, Bern, Switzerland; 2Dept. of Diagnostic Radiology, Eberhard-Karls-University of Tübingen, Tübingen, Germany Insulin resistance and the metabolic syndrome are cardiovascular risk factors with enormous consequences for the individual patient and the health care system. They can be linked with whole body fat (WBF), visceral adipose tissue (VAT), lean body volume (LBV), and whole body volume (WBV) imaged with MRI. In this study, a method is proposed and tested that uses point counting algorithms to determine the above mentioned body compartments in two groups of age-, weight-, height-, and BMI-matched volunteers at 1.5 and 3 Tesla. 2916. Autocalibrating Correction of Spatially Variant Eddy Currents for Three-Point Dixon Imaging Holger Eggers1, Adri Duijndam2 1Philips Research, Hamburg, Germany; 2Philips Healthcare, Best, Netherlands The use of bipolar readout gradients in three-point Dixon imaging increases scan efficiency and separation robustness, but eddy currents lead to phase variations that do not adhere to the assumed linear evolution over echo time. In first approximation, these phase variations are limited to one spatial direction and are easily removed prior to the separation. For large volumes, however, this approximation becomes inaccurate. A correction of these phase variations in all directions that requires no additional calibration data is proposed in this work and demonstrated to substantially improve the fat suppression over large volumes in three-point Dixon imaging. 2917. Three Echo Dixon Water-Fat Separation for Cardiac Black Blood Turbo Spin Echo Imaging Peter Koken1, Holger Eggers1, Tobias Schaeffter2, Peter Börnert1 1Philips Research Europe, Hamburg, Germany; 2Divison of Imaging Sciences, King's College , London, United Kingdom Turbo spin echo (TSE) sequences with black blood and fat suppression preparation pulses are widely used in cardiac MRI. In the presence of B0 inhomogeneity the common prepulse fat suppression techniques often fail. Furthermore, it was recently shown, that the amount and the distribution of fat in the heart could be of diagnostic value. We propose the combination of black blood TSE with a three echo GRASE-like readout and an iterative water fat separation reconstruction without restrictions to the inter echo time. Data were acquired ECG-triggered during breath-hold at both polarities of the readout gradient and combined with accelerated parallel imaging. The combination of TSE with the three point Dixon method could be an interesting new tool in cardiac MRI. 2918. Water Fat Separation with Undersampled TSE BLADE Based on Three Point Dixon Qiang He1,2, Dehe Weng1,3, Xiaodong Zhou1,2, Marc Beckmann1, Cheng Ni1,2 1Siemens Mindit Magnetic Resonance Co. Ltd., Shenzhen, Guangdong, China; 2Life Science and Technology School, Tongji University, Shanghai, China; 3Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China By the method of integrating the total variation regularized iterative reconstruction and water fat separation calculation, the water and fat images with robust and high quality is reconstructed from the undersampled TSE BLADE three point Dixon with less scanning time comparing with full coverage of BLADE k-space trajectory. The final fat and water images have less streaking artifacts comparing with conventional regridding reconstruction methods followed by water-fat separation. Meanwhile, inheriting the benefits of the BLADE scanning, the present method is less sensitive to the motions comparing with Cartesian sampling. 2919. CS-Dixon: Compressed Sensing for Water-Fat Dixon Reconstruction Mariya Doneva1, Peter Börnert2, Holger Eggers2, Alfred Mertins1, John Pauly3, Michael Lustig3,4 1Institute for Signal Processing, University of Lübeck, Lübeck, Germany; 2Philips Research Europe, Hamburg, Germany; 3Electrical Engineering, Stanford University, CA, United States; 4Electrical Engineering, UC Berkeley, CA, United States An integrated Compressed Sensing-Dixon algorithm is proposed, which applies a sparsity constraint on the water and fat images and jointly estimates water, fat and field map images. The method allows scan time reduction of above 3 in 3D MRI, fully compensating for the additional time necessary to acquire the chemical shift encoded data. 2920. Accelerated Robust Fat/Water Separation at 7T Sreenath Narayan1, Fangping Huang1, David Johnson2, Christoper Flask1,3, Guo-Qiang Zhang1, David Wilson1 1Case Western Reserve University, Cleveland, OH, United States; 2Ohio State University, Columbus, OH, United States; 3Unversity Hospitals, Cleveland, OH, United States VARPRO-ICM was previously introduced as a Dixon processing formulation that was able to handle the very large field inhomogeneities seen at 7T. However, long processing times have prevented this formulation from achieving practical use. In this abstract, we present image processing improvements that decrease the processing times required to solve the VARPRO-ICM formulation by a factor of about 70. Hua Ai1, Jingfei Ma1 1The University of Texas M.D. Anderson Cancer Center, Houston, TX, United States Consistent water and fat separation in images with disconnected objects is difficult for a region-growing based Dixon method. Here, we propose to monitor and record the quality index of a recently-proposed algorithm for region-growing at each step. The quality index is then used to automatically segment the disconnected objects into separate sub-images. Finally, the sub-images are consistently recombined on the basis of water and fat spectral asymmetry and slice-to-slice phase correlation. The proposed method was tested on a total of 1106 axial in vivo leg images and was shown to reduce the number of inconsistent slices from 203 to 6. 2922. Optimized Single-Acquisition Lipid- And Water-Selective Imaging at High Field William M. Spees1, Tsang-Wei Tu1, Sheng-Kwei Song1, Joel Garbow1 1Biomedical MR Laboratory, Washington University School of Medicine, St. Louis, MO, United States Side-lobe spatial-spectral excitation and frequency-selective saturation with a binomial-series RF pulse scheme were evaluated for application at high field. Both methods yield separate water- or lipid-selective images in a single acquisition. In most circumstances, the performance of the binomial saturation approach proves to be more robust. A strategy is described for overcoming unwanted artifacts arising from magnetic susceptibility mismatch in small-animal imaging. 2923. Chemical Shift Based Water-Fat Separation with an Undersampled Acquisition Catherine J. Moran1, Ethan K. Brodsky, 12, Huanzhou Yu3, Scott B. Reeder, 12, Richard X. Kijowski2, Walter F. Block1,4 1Medical Physics, University of Wisconsin, Madison, WI, United States; 2Radiology, University of Wisconsin, Madison, WI, United States; 3Global Applied Sciences Lab, GE Healthcare, Menlo Park, CA, United States; 4Biomedical Engineering, University of Wisconsin, Madison, WI, United States The chemical shift based IDEAL decomposition method generally requires redundant sampling at multiple time points. A unique undersampled radial k-space trajectory at each echo time provides a means to accelerate data acquisition while still allowing for robust chemical species decomposition. In this work we present a dual-pass dual-half-echo radial acquisition which utilizes undersampled source images with IDEAL to achieve bSSFP images with high isotropic resolution and robust fat-water separation in the breast and knee. 2924. Influence and Compensation of Fat Signal Dephasing and Decay in Two-Point Dixon Imaging Holger Eggers1 1Philips Research, Hamburg, Germany Fat has a complex spectral composition, which causes its signal to dephase and decay noticeably even over short intervals. The influence of these effects on the extent of fat suppression reached in two-point Dixon imaging is evaluated in this work and is found to strongly depend on the choice of echo times. Moreover, it is shown how more complex spectral models of fat may be incorporated into a generalized two-point Dixon method, with which a more uniform degree of fat suppression is achieved across a range of relevant echo times. 2925. Water Fat Separation with TSE BLADE Based on Three Points Dixon Technique Dehe Weng1,2, Marc Beckmann1 1Siemens Mindit Magnetic Resonance Ltd, Shenzhen, Guangdong, China; 2Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China Three points Dixon method for water and fat separation based on TSE BLADE is proposed. New phase correction using the in-phase image blades is introduced for the reconstruction of the two out-of-phase images in order to keep the water fat chemical shift information so that the water and fat can be separated after the reconstruction. Result shows that water and fat can be separated correctly, furthermore, the method enjoys the advantage of blade, it's less vulnerable to rigid body motion and pulsation etc. 2926. Robust Field Map Estimation Using Both Global and Local Minimia Hojin Kim1,2, Kyung Sung1, Brian Andrew Hargreaves1 1Department of Radiology, Stanford University, Stanford, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States In the least-squares fat/water separation techniques, the residual or cost runction that is minimized contains exactly one or two local minimum, depending on the relative amount of fat and water, and water-fat phase difference. Separation algorithms attempt to find which minimum provides true field-map, but may converge to the incorrect local minimum. Based on this principle, this work proposes a robust field-map estimation technique by tracking two minima at each pixel through region growing process and suggesting more secure way of determining an initial seed for region growing. Catherine D. G. Hines1, Takeshi Yokoo2, Mark Bydder2, Claude B. Sirlin2, Scott B. Reeder1,3 1Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; 2Radiology, University of California-San Diego, San Diego, CA, United States; 3Radiology, University of Wisconsin-Madison, Madison, WI, United States Chemical shift based water-fat separation methods used to quantify fat in tissue are usually based on rapid 2D or 3D spoiled gradient echo methods. In order to avoid bias from differences in T1 between water and fat, a low flip angle is typically used to minimize this source bias. Reducing the flip angle reduces SNR performance, however. In this work, we present an algorithm to maximize the flip angle (to maximize SNR) while maintaining a user-defined allowable error in fat-fraction from T1 related bias. Experimental validation is also shown. Aziz Hatim Poonawalla1, Ann Shimakawa2, Huanzhou Yu2, Charles McKenzie3, Jean Brittain2, Scott Reeder1,4 1Radiology, University of Wisconsin, Madison, WI, United States; 2GE Healthcare, Waukesha, WI, United States; 3Medical Biophysics, University of Western Ontario, London, Ontario, Canada; 4Medical Physics, University of Wisconsin, Madison, WI, United States We have demonstrated the capability to acquire high-spatial resolution 3D volumetric images of the entire abdomen and pelvis, using a highly-accelerated chemical-shift-based water-fat separation technique and a 32-channel coil at 3.0T. The high-quality fat and fat-fraction images obtained by this technique provide unprecedented visualization and delineation of the adipose depot boundaries, with sufficient spatial resolution to allow 3D reformatting for optimal segmentation. This new technique will greatly facilitate rapid quantitative assessment of visceral adipose tissue volume, VAT/SCAT ratio, and total adipose volume within a single-breath-hold acquisition without the need for ionizing radiation. 2929. Preliminary Results of IDEAL Fat/water Separation at 9.4T Sébastien Bär1, Wilfried Reichardt1, Jochen Leupold1 1Dept. of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany IDEAL has emerged as a promising mehtod for rapid fat/water separation. Here we present our first results on the feasibilty of this method on ex-vivo rat images at 9.4T. Dynamic MR, Superresolution, Off-Resonance & Tissue Orientation Hall B Thursday 13:30-15:30 2930. System Dynamics Estimation for Kalman Filtering with Radial Acquisition Mahdi Salmani Rahimi1, Steve R. Kecskemeti2, Walter F. Block1,3, Orhan Unal3 1Biomedical Engineering, University of Wisconsin, Madison, WI, United States; 2Physics, University of Wisconsin, Madison, WI, United States; 3Medical Physics, University of Wisconsin, Madison, WI, United States A novel method has been proposed to use adaptive Kalman filtering and causal DCF based tornado filtering together to reconstruct undersampled MR images for dynamic and time resolved applications. Existing Kalman method uses an initialization scan or a sliding window to estimate system dynamics. In this work, we used tornado filter to infer motion maps for the Kalman process. This helps us to have a better estimation of image changes at every time frame and therefore a more accurate reconstruction. Simulations have been done on a cardiac phantom using radial projections and results were compared to existing techniques. 2931. Deterministic Comparisons of Nonlinear Acceleration Methods Using a Realistic Digital Phantom Leah Christine Henze1, Catherine J. Moran2, Matthew R. Smith2, Frederick Kelcz3, Dan Xu4, Kevin F. King4, Alexey Samsonov3, Walter F. Block, 12 1Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States; 2Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States; 3Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States; 4Global Applied Science Lab, General Electric Healthcare, Milwaukee, WI, United States Several different accelerated imaging methods exist that can improve the acquisition of dynamic data. Clinical adoption of many of these methods has been slow, partially due to the difficulty in conclusively proving the extent to which a specific method provides additional diagnostic information that would not otherwise have been available. We have created a realistic digital phantom from which k-space data for a DCE exam can be simulated and reconstructed by both Cartesian and non Cartesian acceleration methods. We use the phantom to quantitatively analyze and compare the performance of multiple accelerated imaging methods. 2932. Subtraction in View-Shared 3D Contrast-Enhanced MRA Eric Allen Borisch1, Clifton R. Haider1, Roger C. Grimm1, Stephen J. Riederer1 1Radiology, Mayo Clinic, Rochester, MN, United States 3D contrast-enhanced MR Angiography frequently uses a pre-contrast (tissue) acquisition as a subtraction reference (mask) to improve the output image quality and contrast-to-noise ratio. We discuss the appropriate application of this technique to the case of 3D time-resolved view-shared reconstructions, including at what stage in the reconstruction process the subtraction is performed and the selection of effective mask data to suppress magnetization history effects. Irene Paola Ponce1, Martin Blaimer2, Felix Breuer2, Peter Michael Jakob1,2, Mark A. Griswold3, Peter Kellman4 1Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany; 2Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Bavaria, Germany; 3Department of Radiology, University Hospitals of Cleveland and Case Western Reserve University, Cleveland, OH, United States; 4Laboratory of Cardiac Energetics, National Institutes of Health, National Heart, Lung and Blood Institute, Bethesda, MD, United States Many of Parallel MRI techniques are based on a time-interleaved acquisition scheme and allow dynamic imaging with high frame rates. In addition, in order to improve the SNR, the temporal average (also referred to as direct current, DC) is subtracted from the raw data so that only the dynamics of the object is reconstructed. In this work we demonstrate that DC subtraction may lead to temporal filtering effects in form of signal nulls in the temporal frequency spectra of the reconstructed images. We propose to correct the DC by an additional GRAPPA reconstruction prior to subtraction from the raw data. Benjamin K. Felsted1, Ross T. Whitaker1, Matthias C. Schabel2, Edward V.R. DiBella2 1School of Computing, University of Utah, Salt Lake City, UT, United States; 2Department of Radiology, University of Utah, Salt Lake City, UT, United States Introduction: We extend the model-based reconstruction method with a physically based linear-phase model that can account for gadolinium field distortions. Methods: Both constant- and linear-phase models were used in reconstructing two 4D breast DCE k-space acquisitions, retrospectively undersampled at R-factors of 1, 4, and 8. Results: Image reconstruction errors correlate spatially with dynamic image phase estimation errors. The errors of the constant-phase model grow fastest as R increases. Conclusion: The new extension can reduce most of the error from phase. The reconstructions have full spatial resolution without the blurring, ghosting, and ringing spatial artifacts typically associated with aggressive undersampling. 2935. Estimation of Superresolution Performance Gerrit Schultz1, Maxim Zaitsev1 1Diagnostic Radiology - Medical Physics, University Hospital Freiburg, Freiburg, Germany In this contribution a method for the estimation of Superresolution performance is presented. For adequately designed reconstruction methods, the modulations of the rf coil sensitivities can be used to extend the acquired gradient-encoded k-space region. This extension directly results in a resolution improvement. The k-space representation of the sensitivity maps gives a global estimate about the degree of this k-space extension. Resolution is investigated by performing a point spread function analysis. Simulated data are presented and verified with measurement results based on a standard 2D-CSI sequence. 2936. FREBAS Domain Super-Resolution Reconstruction of MR Images Satoshi Ito1, Yoshifumi Yamada1 1Research Division of Intelligence and Information Sciences, Utsunomiya University, Utsunomiya, Tochigi, Japan Super-resolution is a method of generating images beyond the limit of the resolution. Recently, a method by which to realize super-resolution by a technique that performs registration by a sub-pixel unit from several pieces of an image has been reported. Gerchberg-Papoulis (GP) method is known to realize super-resolution from a single image and signal, however, spatial resolution will not be improved well when it is based on the Fourier transform. On the other hand, GP method involving convolution integral can expand the signal band easily and the resultant image has higher resolution. In this study, we investigated the super-resolution of images using FREBAS transform that can be considered as a kind of multi-resolution image analysis based on convolution integral. Improvement of resolution on the image space with reference to the scaling parameter of FREBAS transform is examined. Nathanael Kuo1, Junghoon Lee1, Clare Tempany2, Matthias Stuber1, Jerry Prince1 1Johns Hopkins University, Baltimore, MD, United States; 2Brigham and Women's Hospital, Boston, MA, United States An MRI pulse sequence and a corresponding image processing algorithm to localize prostate brachytherapy seeds during or after therapy are presented. Inversion-Recovery with ON-resonant water suppression (IRON) is an MRI methodology that generates positive contrast in regions of magnetic field susceptibility, as created by brachytherapy seeds. Phantoms comprising of several materials found in seeds were created to assess the usability of IRON for imaging seeds. Resulting images show that seed materials are clearly visible with high contrast using IRON. A seed localization algorithm to process IRON images demonstrates the potential of this imaging technique for seed localization and dosimetry. Haitao Zhu1, Kazuyuki Demachi1 1Department of Nuclear Engineering, The University of Tokyo, Tokyo, Japan The objective of this work is to apply a post-processing method in MR-lymphography with superparamagnetic iron oxide nanoparticle (SPION) enhancement to achieve positive contrast in the image. The method analyzes the echo position shift caused by susceptibility gradient and uses this criterion to enhance region with large gradient caused by SPIONs. Both phantom and animal experiments are performed to test the method. Results show that this positive contrast method can generate enhanced signal at the region targeted by SPIONs and might provide additional information in MR-lymphography. Vicente Parot1,2, Carlos Sing-Long1,2, Carlos Lizama3, Sergio Uribe, 2,4, Cristian Tejos1,2, Pablo Irarrazaval1,2 1Department of Electrical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile; 2Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, Chile; 3Department of Mathematics and Computer Science, Universidad de Santiago de Chile, Santiago, Chile; 4Department of Radiology, Pontificia Universidad Catolica de Chile, Santiago, Chile In Magnetic Resonance Imaging (MRI) field inhomogeneities produce severe distortions, especially with long acquisition sequences, e.g. EPI. Shimming or post-processing strategies are usually applied to correct those distortions. However, those approaches require additional hardware or long processing times. We propose an alternative reconstruction method based on the Fractional Fourier Transform (FrFT) assuming spatially-varying quadratic fields. We tested our method in phantoms and in vivo acquisitions. Results demonstrate the ability of our reconstruction scheme to correct the geometric distortions that appear in standard Fourier Transform reconstructions under non homogeneous fields. Hendrik de Leeuw1, Peter R. Seevinck1, Clemens Bos2, Gerrit H. van de Maat1, Chris J.G. Bakker1 1Image Sciences Institute, Utrecht, Netherlands; 2Philips healthcare With the advent of short-TE acquisitions, such as UTE and SWIFT, center out radial acquisition schemes to fill k-space are gaining interest. Although these short TE acquisitions minimize signal dephasing, they still suffer from field inhomogeneities in terms of geometric distortion. Still geometrically accurate depiction and localization of local field disturbers can be achieved by a 3D center-out radial acquisition by using off-resonance acquisition or reconstruction (RASOR). The advantage of RASOR reconstruction is a more precise determination of shape and location of the field disturbance, while retaining the original image. Harsh K. Agarwal1, Xiaofeng Liu1, Khaled Z. Abd-Elmoniem2, Jerry L. Prince1 1Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD, United States; 2National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States Off-resonance due to magnetic field inhomogeneity causes geometric distortion in tagged images acquired using a segmented spiral k-space data acquisition. This causes erroneous alignment of horizontal and vertical tag acquisitions and inaccurate displacement estimation. A technique based on fast marching HARP refinement is proposed to estimate and correct for the distortion. Improved motion estimation is demonstrated on an in vivo data set. 2942. Multi-GPU Implementation for Iterative MR Image Reconstruction with Field Correction Yue Zhuo1, Xiao-Long Wu2, Justin P. Haldar2, Wen-mei W. Hwu2, Zhi-Pei Liang2, Bradley P. Sutton1 1Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States; 2Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States Nowadays Graphics Processing Units (GPU) leads high computation performance in science and engineering application. We propose a multi-GPU implementation for iterative MR image reconstruction with magnetic field inhomogeneity compensation. The imaging model includes the physics of field inhomogeneity map and its gradients, and thus can compensate for both geometric distortion and signal loss. The iterative reconstruction algorithm is realized on C-language based on Compute Unified Device Architecture (CUDA). Result shows the performance of multi-GPU gains significant speedup by two orders of magnitude. Therefore, the fast implementation make the clinical and cognitive science requirements are achievable for accurate MRI reconstruction. 2943. Fiber Orientation Dependance of T2* Relaxation Time in the Whole Human Brain at 3T Benjamin Bender1, Uwe Klose1 1University Hospital Tübingen, Department of Diagnostic and Interventional Neuroradiology, Tübingen, Germany Recent publications suggest a relationship between white matter fiber orientation and T2* contrast at higher field strengths. In this study the relationship between fiber orientation and B0 for normal and tilted head position was examined in the whole human brain at 3T. As previously shown by Wiggins et al. for the cingulum and corpus callosum, WM signal intensity in the whole brain changed when the head was tilted. Blood vessels following the fiber tracts could explain the relationship found between B0 and relaxation rate, while a magic angle effect cannot explain the measured relationship. 2944. Sensitivity of MRI Resonance Frequency to the Orientation of Brain Tissue Microstructure Jongho Lee1, Karin Shmueli1, Masaki Fukunaga1, Peter van Gelderen1, Hellmut Merkle1, Afonso C. Silva2, Jeff H. Duyn1 1Advanced MRI/LFMI/NINDS, National Institutes of Health, Bethesda, MD, United States; 2CMU/LFMI/NINDS, National Institutes of Health, Bethesda, MD, United States Here we demonstrate microstructural orientation affects the MRI resonance frequency. The experiment was designed to avoid macroscopic susceptibility effect to identify true microstructural effect. We suggest an origin related to anisotropic susceptibility. Relaxometry Hall B Monday 14:00-16:00 2945. Wide-Range T1 Mapping Using Two Variable Flip Angle Acquisitions Rahul Sarkar1, Alan R. Moody1,2, James Q. Zhan2, General Leung1,2 1Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 2Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada Variable flip angle (VFA) methods using two optimized flip angles have become popular for in-vivo T1 mapping within a limited range of a specific T1 of interest. The range limitation in this approach is generally due to bias against long T1s in the signal-dynamic range product used for flip angle optimization. This study presents a new strategy for flip angle pair selection that mitigates this bias to provide highly uniform accuracy and precision across the biological T1 range. In using only two flip angle acquisitions, this method represents a rapid approach to wide-range VFA T1 mapping. Naoharu Kobayashi1, Hironaka Igarashi1, Tsutomu Nakada1 1Center for Integrated Human Brain Science, Brain Research Institute, University of Niigata, Niigata, Japan We present a new method for measuring a longitudinal relaxation time, T1, for a surface coil application utilizing adiabatic saturation pulses, referred to here as time-optimized partial inversion recovery (TOPIR). The recovery delays before and after the inversion pulse were optimized to sample data points such that the total sequence time was minimized under a specified dynamic range of the recovery curve. Accuracy of the method was validated by comparing the values obtained utilizing conventional inversion recovery sequence. The method enabled a two dimensional T1 mapping of a mouse brain using a 6 point recovery curve in 2036 s. 2947. The Effect of Heart Rate in Look-Locker Cardiac T1 Mapping Glenn S. Slavin1, Ting Song1, Jeffrey A. Stainsby2 1Applied Science Laboratory, GE Healthcare, Bethesda, MD, United States; 2Applied Science Laboratory, GE Healthcare, Toronto, ON, Canada Because inversion times in cardiac Look-Locker acquisitions are a function of heart rate, T1 measurements can be incorrect. Pulse sequence modifications to account for heart rate variability and its effect on the magnetization recovery curve can significantly improve T1 accuracy. Miriam Rabea Kubach1, Kaveh Vahedipour2, Ana Maria Oros-Peusquens2, Tony Stoecker2, N. Jon Shah2,3 1Institute of Neuroscience and Medicine , Forschungszentrum Juelich, Juelich, Germany; 2Institute of Neuroscience and Medicine, Forschungszentrum Juelich, Juelich, Germany; 3Faculty of Medicine, Department of Neurology, , RWTH Aachen University, JARA,, Aachen, Germany T1 is an MRI parameter very sensitive to pathological changes. Proper T1-mapping is therefore vital for many MRI applications, but the variability of T1 values within different methods is larger than within a group of volunteers measured with the same method. The accuracy of the T1 determination is affected by a number of rectifiable parameters but also influenced by MT in ways, which are strongly method-dependent and usually not quantified. We present numerical simulations, based on an existing software package JEMRIS, which allow one to simulate MR sequences considering MT effects. We investigate changes in the T1 relaxation of the observable water component due to the presence of and exchange with a bound proton pool. A simple pulse-acquire sequence is used for simulations, which can be the elementary building block of more realistic MR imaging sequences. 2949. Fast T1/B1 Mapping Using Multiple Dual TR RF-Spoiled Steady-State Gradient-Echo Sequences Tobias Voigt1, Stefanie Remmele2, Ulrich Katscher2, Olaf Doessel1 1Institute of Biomedical Engineering, University of Karlsruhe, Karlsruhe, Germany; 2Philips Research Europe, Hamburg, Germany Efficient and accurate baseline T1 and B1 quantification is a pre-requisite for standardized and clinical Dynamic Contrast-Enhanced MRI (DCE-MRI). This study investigates a new approach called Multiple TR B1/T1 Mapping (MTM), capable of fast, simultaneous B1 and T1 mapping. In this work, MTM is analysed with respect to its T1 mapping performance in comparison with an inversion recovery reference sequence and in due consideration of the limited time allowed in a clinical set-up. In calibrated phantom measurements, MTM T1 mapping was found to be more accurate than IR-TSE, inter alia due to its intrinsic B1 correction mechanism. 2950. Fast T1 Mapping at 7T Using Look-Locker TFEPI Emma Louise Hall1, Ali M. Al-Radaideh1, Su Y. Lim2, Susan T. Francis1, Penny A. Gowland1 1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Clinical Neurology, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom Ultra high field has the benefit of increased SNR to facilitate high resolution imaging. However, the lengthened relaxation time requires long scan times to produce high resolution T1 maps due to the need to allow the system to return to equilibrium. Here we present a Look-Locker TFEPI sequence that allows the acquisition of high resolution, 1.25mm isotropic, T1 maps with large volume coverage at 7T in less than 6 minutes. 2951. Accelerated Mapping of T1 Relaxation Times Using TAPIR Klaus Möllenhoff1, N Jon Shah1,2, Eberhard D. Pracht1, Tony Stöcker1 1Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Forschungszentrum Juelich GmbH, Juelich, Germany; 2Faculty of Medicine, Department of Neurology, RWTH Aachen University, JARA, Aachen, Germany TAPIR is an extremely flexible Look-Locker sequence that allows choices to be made regarding coverage and number of time points acquired on the recovery curve. We are using AFP inversion pulses to be more accurate and a segmented EPI readout together with parallel imaging to reduce the total acquisition time. Philipp Ehses1, Vikas Gulani2, Peter Michael Jakob1, Mark A. Griswold2, Felix A. Breuer3 1Dept. of Experimental Physics 5, Universität Würzburg, Würzburg, Germany; 2Department of Radiology, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, OH, United States; 3Research Center Magnetic Resonance Bavaria (MRB),, Würzburg, Germany The IR TrueFISP sequence has been shown to be a promising approach for the simultaneous quantification of proton density, T1 and T2 maps. However, delays between individual segments are required in order to allow the magnetization to recover, resulting in relatively long scan times. Recently, a modified IR TrueFISP method has been proposed, which does not necessitate relaxation delays. This method was combined with a radial stack-of-stars acquisition with golden-ratio based profile order, in order to rapidly obtain a full set of parameter maps of the brain in three dimensions. 2953. The Influence of Finite Long Pulse Correction on DESPOT2 Hendrikus Joseph Alphons Crooijmans1, Klaus Scheffler1, Oliver Bieri1 1Division of Radiological Physics, Department of Medical Radiology, University of Basel Hospital, Basel, Switzerland The DESPOT2 theory is based on the assumption of instantaneous RF pulses. However, this is a pure theoretical assumption and it can never be met in practice, only approached with short pulse durations. Explicitly in cases where MT effect reduction is desired, long RF pulses are applied and the assumption is not met leading to deviation of calculated T2 from true T2 values. The implementation of a correction for finite pulse effects in the DESPOT2 theory makes the method independent of RF pulse duration and marginal deviations of around 1% of the true T2 are obtained for the calculated T2. Markus Kraiger1, Florian Knoll1, Christian Clason2, Rudolf Stollberger1 1Institute of Medical Engineering, Graz University of Technology, Graz, Austria; 2Institute for Mathematics and Scientific Computing, University of Graz, Graz, Austria Nonlinear parallel imaging reconstruction using an iterative regularized Gauss Newton method has shown its potential in several applications. This technique determines both the coil sensitivities and the image from undersampled multi-coil data. It enables high acceleration factors without pronounced local enhancement of noise. The numerical implementation of this sophisticated method requires data normalization steps which are usually performed individually for each slice and echo. In this study it was investigated if this type of reconstruction is applicable for quantitative imaging despite the complex reconstruction including image individual normalization. For that purpose high resolution multi-echo imaging with different acceleration factors was used for the quantification of the transverse relaxation time (T2). 2955. In-Vivo and Numerical Studies of Myelin Water Fraction in Rat Spinal Cord Kevin D. Harkins1,2, Adrienne N. Dula1,2, Mark D. Does, 1,3 1Institute of Image Science, Vanderbilt University, Nashville, TN, United States; 2Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; 3Biomedical Engineering, Vanderbilt University, Nashville, TN, United States The myelin water fraction (MWF) estimated from multi-exponential T2 analysis is an effective marker of myelin in tissue, but there is evidence that the MWF is underestimated due to the exchange of water between myelin and other tissue compartments. In this work, in-vivo experiments confirm a bias in the MWF within rat spinal cord. Numerical studies further suggest that exchange can account for the variation in MWF, and that exchange between T2 components may be limited by the apparent diffusivity of myelin water. 2956. Evaluation of a Fast T2 Mapping Method in the Brain Julien Sénégas1, Stefanie Remmele1, Wei Liu2 1Philips Research Europe, Hamburg, Germany; 2Philips Research North America, Briarcliff, NY, United States T2 measurements provide important information about the mobility and chemical environment of water in the tissue of interest. The most frequent method for accurate T2 quantification uses multi-echo spin-echo (MESE incorporating multiple refocusing pulses in each repetition time following the CPMG sequence. To cover a wide range of T2 values, the number of spin echoes and corresponding RF pulses needs to be relatively large, resulting in increased TR, long scan durations, and a high SAR. Recently, a fast T2 mapping method, reducing the total number of phase encoding steps of a MESE sequence without sacrificing spatial resolution nor the dynamic range of T2 values, was proposed and evaluated in simulations and pre-clinical experiments. In this work, the accuracy of this acceleration technique for T2 mapping in the human brain was assessed in a larger group of volunteers. 2957. T1 Corrected Fast T2 Mapping Using Partially Spoiled SSFP Oliver Bieri1, Klaus Scheffler1, Carl Ganter2 1Radiological Physics, University of Basel Hospital, Basel, Switzerland; 2Department of Diagnostic Radiology, Technical University Munich, Munich, Germany Only recently a fast method for quantitative T2 mapping was introduced based on partially RF spoiled SSFP sequences (T2-pSSFP). It has been shown that for large flip angles, estimation of T2 is independent on T1 but becomes sensitive for low to moderate excitation angles. We will show that a correction of T2-pSSFP with T1 is possible and yields accurate T2 values for flip angles down to 30°. This offers the possibility for acquisitions with higher SNR, but requires prior knowledge of T1. 2958. Free Breathing Myocardial T2 Measurements Maelene Lohezic1,2, Anne Menini2,3, Brice Fernandez1,2, Damien Mandry, 2,4, Pierre-Andre Vuissoz2,3, Jacques Felblinger2,3 1Global Applied Science Lab., GE Healthcare, Nancy, France; 2IADI, Nancy-Université, Nancy, France; 3U947, INSERM, Nancy, France; 4CHU Nancy, Nancy, France Myocardial T2 measurements usually require multiple breath hold acquisitions, leading to patient discomfort and misregistrations between images. We present a new method allowing free breathing T2 quantification that combines respiratory motion estimation, motion compensated reconstruction and T2 calculation. It has been validated on five healthy volunteers and has shown no significant difference compared to the standard breath hold technique. A morphological proton density weighted image is also obtained, allowing accurate examination of heart structures. Such technique could be used for cardiac iron overload assessment or detection of early rejection of heart transplant, even in non cooperative patients such as children. 2959. Temporal Phase Correction of Quantitative T2 Data Thorarin A. Bjarnason1, Cheryl R. McCreary1, Jeff F. Dunn1, J Ross Mitchell1 1University of Calgary, Calgary, AB, Canada Magnetic resonance images are formed typically by taking the magnitude of reconstructed complex values. The magnitude operation changes the noise distribution from Gaussian to Rician. This operation causes artifacts in T2 distributions calculated using the non-negative least squares algorithm. The artifacts caused by non-Gaussian noise distributions are becoming more relevant as scientists begin to identify tissue compartments with small intensity long T2 decays. Here we propose, and examine, a temporal phase correction method allowing T2 distributions to be created from complex quantitative T2 data. 2960. T2 Mapping Using T2prepared-SSFP: Optimizing Echo Time, Flip Angle and Parameter Fitting Shivraman Giri1, YiuCho Chung2, Saurabh Shah2, Hui Xue3, Jens Guehring3, Sven Zuehlsdorff2, Orlando P. Simonetti 1The Ohio State University, Columbus, OH, United States; 2Siemens Healthcare; 3Siemens Corporate Research In this study, we analyze the effect of flip angles and choice of T2Prep times in T2 quantification using Magnetization prepared balanced SSFP sequence. Daniel Lee Shefchik1, Andrew Scott Nencka1, Andrzej Jesmanowicz1, James S. Hyde1 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States The gradient-echo asymmetric spin-echo pulse sequence (GREASE) allows for the production of T2 and T2* maps. In order to obtain high resolution maps, while maintaining signal, the GREASE sequence was modified to accelerate the acquisition of the images three different ways. The modifications included partial k-space GREASE [2], generalized autocalibrating partially parallel acquisitions (GRAPPA) Grease [3], and partial k-space GRAPPA GREASE. The sequences are implemented and compared to the original GREASE sequence to determine the best technique to obtain quality T2 and T2* maps. Heiko Schmiedeskamp1, Matus Straka1, Roland Bammer1 1Lucas Center, Department of Radiology, Stanford University, Stanford, CA, United States There is an increased interest in combined gradient-echo and spin-echo pulse sequences for applications in PWI and fMRI, facilitated by the differences in signal decay of gradient echoes and spin echoes depending on the mean vessel size within a voxel. This abstract deals with issues of mismatched slice profiles in such pulse sequences between the 90° excitation pulse and the 180° refocusing pulse, and it introduces a scaling factor for improved T1-independent R2 and R2* quantification. 2963. Multi Echo Spiral Imaging : Optimized K-Space Trajectories for T2* Quantification. Nicolas Pannetier1,2, Mohamed Tachrount1,2, Christoph Segebarth1,2, Emmanuel Louis Barbier1,2, Laurent Lamalle3 1Inserm, U836, Grenoble, France; 2Université Joseph Fourier, Grenoble Institut des Neurosciences, UMR-S836, Grenoble, France; 3IFR n°1, INSERM, Grenoble, France Effective and theoretical k-space trajectories differ due to eddy currents or gradient hardware imperfections. In this study we propose a fast two steps approach to optimized k-space trajectories in multi-echo spiral imaging. Once optimized, images were acquired on rat brain and T2* map was estimated. Kai Zhong1, Ralf Deichmann2, Weiqiang Dou1, Oliver Speck1 1Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Saxon-Anhalt, Germany; 2Brain Imaging Center, University Frankfurt, Frankfurt, Germany Previous studies at 7 T have related T2* maps to the iron deposition in brain tissue. However, the field inhomogeneity and susceptibility distortion at 7 T are significantly higher compared to lower field. This potentially distorts the true T2* values and could lead to false estimation of the tissue iron content. In this study, T2* correction based on the susceptibility gradients was applied to 7 T and can improve the resulting T2* maps. This method therefore should help to improve the accurate determination of T2* at 7 T for clinical studies. On the other hand, stronger dephasing is encountered, so thinner slices should be chosen than at lower fields to avoid systematic errors. 2965. R2* Reference Phantoms for Longitudinal Research Studies Matthew T. Latourette1, James E. Siebert1 1Radiology, Michigan State University, East Lansing, MI, United States In longitudinal research studies that employ R2*/T2* quantitation, reference phantoms can serve to improve the sensitivity and reproducibility of R2* measurements through detection and correction of bias and reduction of the variance of pooled study data. Stable phantoms comprised of agarose and carageenan gel doped with SPIO, NiCl2, and methylisothiazolinone were developed, enabling reliable R2* measurements that are adequately insensitive to temperature variations near room temperature. The phantoms R2* dependence on B0 was evaluated at field strengths of 0.35T, 0.7T, 1.5T, 3.0T. Chemical stability has been evaluated since phantom construction in April 2009. 2966. Transverse Relaxation of Water in Ferritin Gel: Relative Contributions of Iron and Gel Nobuhiro Takaya1, Hidehiro Watanabe1, Fumiyuki Mitsumori1 1National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan Transverse relaxation of tissue water in human brain was explained with a linear combination of contributions from ferritin iron and the macromolecular mass fraction defined as 1-water fraction. This work examined whether the same scheme is applicable to relaxation of a model system composed of ferritin and agarose gel. The result of multiple regression analysis on the system showed that transverse relaxation in the system was described in the same manner as in human brain. B0 dependence of R2 demonstrated that the relaxation mechanism due to iron in gel samples is identical to that reported for a ferritin solution. Stephan William Anderson1, Jorge A. Soto1, Osamu Sakai1, Hernan Jara1 1Radiology, Boston University Medical Center, Boston, MA, United States The purpose of this work was to test a pulse sequence for spatial- and spectral-selective qMRI relaxometry in vivo for deriving qMRI parameters in brain imaging. The brain of a volunteer was imaged using both non-chemically selective mixed-TSE sequence as well as the SSE-mixed-TSE pulse sequence to derive parametric maps of PD, T1, T2 (including secular-T2), and ADC of the brain. T2 was found to be consistently longer for the SSE-mixed-TSE pulse sequence. Spectrally selective qMRI may offer insight into both normal structures as well as pathology without the confounding effects of lipids. 2968. Simultaneous T1 and T2 Mappings Using Partially Spoiled Steady State Free Precession (PSSFP) Paulo Loureiro de Sousa1,2, Alexandre Vignaud3, Laurie Cabrol1,2, Pierre G. Carlier1,2 1Institut de Myologie, Laboratoire de RMN, Paris, France; 2CEA, I2BM, Paris, France; 3Siemens Healthcare, Saint Denis, France A fast 3D T2 mapping technique based on two partially Spoiled Steady State Free Precession (pSSFP) acquisitions has recently been presented. For most human soft tissues, accurate T2 measurements can only be obtained for high flip angle (FA) leading to SAR issues especially at high field. In this work we proposed an analytical expression derived from pSSFP theory which allowed us to introduce a more flexible T2 mapping technique. By doubling data collection, T1 map can also be extracted. The method has been validated on a phantom comparing pSSFP results with standard T1 and T2 measurements. Philipp Ehses1,2, Vikas Gulani3, Stephen Yutzy3, Nicole Seiberlich3, Peter Michael Jakob1,2, Mark A. Griswold3 1Dept. of Experimental Physics 5, Universität Würzburg, Würzburg, Germany; 2Research Center Magnetic Resonance Bavaria (MRB), , Würzburg, Germany; 3Department of Radiology, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, OH, United States The IR TrueFISP sequence has been shown to be a promising approach for the simultaneous quantification of proton density, T1 and T2 maps. For accurate quantification, segmentation is usually necessary, leading to an increase in scan time. In this work, a full set of parameter maps was obtained in a single-shot by combining the IR TrueFISP sequence with a golden-ratio based radial trajectory and using extensive view-sharing. The effects of both magnetization transfer and the violated instantaneous RF assumption on parameter quantification were further analyzed by prolonging the RF pulses and TR (thereby reducing RF power and thus MT). 2970. T1 and T2 Quantification for Short T2 Tissues: Challenges and Solutions Michael Carl1, Jiang Du2, Jing-Tzyh Alan Chiang2, Eric Han1, Christine Chung2 1GE Healthcare, Waukesha, WI, United States; 2University of California, San Diego The relaxation properties T1 and T2 of MRI images are important parameters in assessment of pathology. Many musculoskeletal (MSK) tissues (cortical bone, tendon, ligaments, etc) have very short transverse relaxation times. UTE imaging of MSK tissues can pose unique challenges for the quantification of the longitudinal or transverse relaxation. We describe these challenges and offer simple solutions to help overcome them. Hernan Jara1, Stephan W. Anderson1, Osamu Sakai1, Jorge A. Soto1 1Boston University School of Medicine, Boston, MA, United States Purpose: There is great need for multi-spectral quantitative-MRI (qMRI) pulse sequences that can be readily implemented in MRI scanners of different manufacturers and field strengths. Methods: The Tandem-IR-DE-FSE sequences were implemented in GE (1.5T-SIGNA HDx) and Bruker 11.7T scanners. Results: Excellent directly-acquired and qMRI map image quality was obtained with both scanners: PD, T1, and T2 maps of the brain are of good image quality and also are give qMRI measures in good agreement with accepted values. Conclusion: The Tandem IR-DE-FSE sequence can produce multispectral qMRI maps of PD, T1, and T2 that are self co-registered, high spatial resolution, and with clinical coverage. 2972. High Resolution Multispectral QMRI Protocol: PD, T1, T2, T2*, ADC, MT Stephan William Anderson1, Jorge A. Soto1, Hernan Jara1 1Radiology, Boston University Medical Center, Boston, MA, United States The purpose of this study was to develop a high-resolution, multi-spectral, quantitative magnetic resonance imaging (qMRI) pulse sequence protocol to interrogate T1, T2, T2*, proton density (PD), diffusion coefficient, and magnetization transfer parameters at ultra-high field (11.7T) MRI. This multi-spectral qMRI pulse sequence was applied to a qMRI phantom containing water, agarose gels, sucrose solutions, and olive oil. Also, the protocol was applied to ex vivo liver imaging of a murine model of steatohepatitis as well as ex vivo murine brain imaging. This comprehensive, multi-spectral qMRI protocol was successfully implemented at 11.7T MRI 2973. Comparison of Magnetic Field Correlation in Brain at 1.5 and 3 Tesla Caixia Hu1,2, Jens H. Jensen1, Casian Monaco, Kathleen Williams, Joseph A. Helpern1,2 1Radiology, New York University School of Medicine, New York, NY, United States; 2Center for Advanced Brain Imaging, Nathan S. Kline Institute, Orangeburg, NY, United States The magnetic field correlation is theoretically predicted to scale as the square of the applied field. This was verified experimentally in brain for two subjects by scanning them at 1.5T and 3T. The magnetic field correlation was estimated by using a recently proposed MRI method based on asymmetric spin echoes. The consistency of the experimental results with the theoretical prediction constitutes an important validation for the imaging method and helps to justify its application at clinical field levels. Magnetic field correlation can be of interest for studying brain iron changes associated with neuropathologies, such as Alzheimers disease and multiple sclerosis. Ultra Short TE Hall B Tuesday 13:30-15:30 2974. Ultra-Short Echo-Time (UTE) Imaging for Early Diagnosis of Dental Demineralization Anna-Katinka Bracher1, Christian Hofmann2,3, Said Boujraf4, Axel Bornstedt1, Erich Hell5, Johannes Ulrici5, Axel Spahr2, Volker Rasche1 1Department of Internal Medicine II, University Hospital of Ulm, Ulm, Baden-Württemberg, Germany; 2Department of Operative Dentistry, Periodontology and Pedodontics, University Hospital of Ulm, Ulm, Germany; 3Department of Internal Medicine II, University Hospital of Ulm, Ulm, Baden-Württemberg, Germany; 4Department of Biophysics and Clinical MRI Methods, Faculty of Medicine and Pharmacy, University of Fez, Morocco; 5Sirona Dental Systems GmbH, Bensheim, Germany Due to the high mineral content, the concentration of free protons is extremely low causing only weak magnetization and due to the susceptibility interfaces in the mineral structures, the spin-spin relaxation rates results below 1ms for dentin and below 250µs for enamel. During caries lesion formation, some increase in liquid content resulting from the production of acid or caused by water penetrating into the lesion through the porous demineralized enamel layer is expected. The performance of ultra-short echo time (UTE) MRI for early assessment of lesion formation was investigated and compared to X-ray imaging. Robert Daniel O'Connell1, Steen Moeller1, Djaudat Idiyatullin1, Curt Corum1, Michael Garwood1 1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States A comparison is made between infinitely short RF pulses (delta), hard pulses and SWIFT using the Ernst energy equation and Bloch simulations. Simulation results are reported for each pulse sequence for on- and off-resonance systems at T1=T2. The SWIFT, delta pulse, and long T1,2 on-resonance hard-pulse sequences are described by the Ernst equations. On-resonance hard pulses have signal energy loss for short T1,2. Off-resonance hard pulses are not described by the Ernst equations. In addition to being unaffected by resonance offsets, for any flip angle the SWIFT sequence results in having a signal energy peak at shorter T1,2 than the other sequences. 2976. 3D Ultrashort Echo Time (UTE) Imaging in the Brain at 7T Peder E. Z. Larson1, Duan Xu1, Daniel B. Vigneron1 1Radiology and Biomedical Imaging, University of California - San Francisco, San Francisco, CA, United States Ultrashort echo time (UTE) imaging of the brain has the potential for direct detection of myelin, calcifications and other short-T2 components that are altered in neurodegenerative diseases and other neurological pathologies. Ultra high-field MRI at 7T offers improved SNR for detection of these components which generally have low signal intensity. In this project, we have developed a 3D radial UTE acquisition for 7T brain imaging providing full head coverage in just over 5 mins. Both dual-echo subtraction and off-resonant saturation pulses were applied yielding good contrast of connective tissues and white matter short-T2 components. 2977. Single Point Sequences with Shortest Possible TE GOSPEL David Manuel Grodzki1,2, Michael Deimling1, Björn Heismann1, Hans-Peter Fautz1, Peter Jakob2 1Magnetic Resonance, Siemens Healthcare, Erlangen, Bavaria, Germany; 2Department of Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany We present a novel single point sequence, GOSPEL (Gradient Optimised Single Point Imaging with Echo-time Leveraging). Based on a RASP / SPRITE sequence, it uses the shortest possible echo-time for each acquired k-space point. Especially for clinical scanners with limited gradient strength, the reduction of the echo-time enables an improved measurement of tissues with short T2 times. We present an image of a human hand, depicting both the bone structure and tendons. The results indicate that GOSPEL can be used for bone and tendon imaging or MR-PET attenuation correction. 2978. Imaging of Renal Stones in Vitro with UTE MRI Aya Yassin1, Ivan Pedrosa1, Michael Kearney2, Elizabeth Genega3, Neil M. Rofsky1, Robert E. Lenkinski1 1Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 2Urology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 3Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States Renal stones have short T2 values and are therefore difficult to demonstrate when using conventional MR sequences. We utilized the UTE MR sequence to characterize renal stones in vitro. Thirty-six stones from patients were scanned, and T1 and T2 values were calculated for every stone. The results were correlated with the composition. The 21/36 visualized stones showed high signal on UTE images. Having demonstrated the feasibility of the UTE sequence for imaging renal stones we anticipate employing this technique on a wider scale to patients suspected of having renal stones, especially to those in whom it is desirable to avoid ionizing radiation exposure such as children, women of child bearing age and pregnant females. 2979. MRI Signal Delay: A Potential Probing Mechanism for Cellular Imaging in the Brain Yongxain Qian1, Fernando E. Boada1 1MR Research Center, Radiology, University of Pittsburgh, Pittsburgh, PA, United States This work presents new observations of the delay of MRI signal in human brain on 3T MRI scanner with ultrashort echo time (UTE) acquisitions. The MRI signal delay was related, by our hypotheses, to those parameters such as ion concentration and T2* relaxation time, that characterize cellular micro environment inside/outside a cell as well as cell membrane. An electromagnetic (EM) interaction between RF pulse and mobile ions in tissue was employed to illuminate the delay of MRI signals. 2980. Detection of Short T2 Component in Brain by SWIFT Lauri Juhani Lehto1, Djaudat Idiyatullin2, Curtis Andrew Corum2, Michael Garwood2, Olli Heikki Gröhn1 1A. I. Virtanen Institute for Molecular Medicine, University of Kuopio, Kuopio, Eastern Finland, Finland; 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States The aim of this work was to directly detect signal from the short T2 component in the brain using the SWIFT sequence that allows almost simultaneous excitation and detection. To detect the short T2 component, the overwhelming long T2 component signal was suppressed either by using long adiabatic inversion pulses or by suppressing the short T2 component and subtracting that from a normal SWIFT image. Results show relative enhancement of white matter structures in the brain. The contrast in the latter approach is interpreted to have a contribution also from MTC and thus represents combined direct and indirect detection of the short T2 pool. Magnetization Transfer & CEST Hall B Wednesday 13:30-15:30 2981. Pulsed CEST for the Quantification of PH Kimberly Lara Desmond1, Greg J. Stanisz1,2 1Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 2Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada We present a method for the quantification of pH using a pulsed chemical exchange saturation transfer (CEST) method. Experimental data is from a phantom model consisting of 1M ammonium chloride in 10mM citric acid buffer for the modification of pH. This data is fit using a two-compartment Bloch equation model of exchange in the presence of off-resonance excitation. A linear relationship is observed between the log of the fitted exchange rate and the true pH of the phantom. 2982. Ytterbium (Yb)-Based PARACEST Agent: Feasibility of CEST Imaging on a Clinical 3.0 T Scanner Yukihisa Takayama1, Akihiro Nishie1, Takashi Yoshiura1, Tomohiro Nakayama1, Eiki Nagao1, Naoki Kato2, Satoshi Yoshise2, Shutaro Saiki2, Dirk Burdinski3, Holger Grull3, Jochen Keupp3, Hiroshi Honda1 1Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; 2Philips Electronics Japan, Tokyo, Japan; 3Philips Research Europe, Hamburg, Germany Chemical Exchange-dependent Saturation Transfer (CEST) is a novel contrast mechanism for magnetic resonance (MR) imaging, but it is not yet common in clinical practice. We investigated the feasibility of CEST imaging on a clinical MR scanner by in vitro study using a ytterbium complex of paramagnetic CEST agents. The CEST effect could be observed at specific offset frequencies. In addition, it increased and decreased depending on the degrees of concentration, pH or solution. We showed the clinical potential of CEST imaging using these agents, but further modifications, such as optimized presaturation RF pulse, imaging protocols or other techniques, remain necessary.
2983.
Magnetic Resonance Imaging of the Neurotransmitter GABA in-Vivo 1CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Biology, Wake Forest University, Winston-Salem, NC, United States; 3Department of Neurology, and Center for Functional Neuroimaging, University of Pennsylvania, Philadelphia, PA, United States Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter of the brain and plays a critical role in multiple central nervous system diseases. The objective of this study was to characterize the chemical exchange saturation transfer (CEST) effect of the -NH2 protons of GABA and to demonstrate GABA imaging in the human brain at 7T. The Z-spectrum of GABA showed a pH sensitive asymmetry around ~2.75 ppm downfield to the water resonance. CEST imaging of healthy human volunteers clearly showed the distribution of GABA CEST contrast in different regions of the brain with negligible contrast from cerebrospinal fluid 2984. CEST and Sodium Imaging of Glycosaminoglycans In-Vivo on the 3T: Preliminary Results Elena Vinogradov1, Alexander Ivanishev1, Aaron K. Grant1, Ron N. Alkalay2, David B. Hackney1, Robert E. Lenkinski1 1Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States; 2Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States Quantitative assessment of Glycosaminoglycans (GAGs) in the clinical environment can assist with characterization of disorders associated with cartilage degradation and loss. Sodium imaging and Chemical Exchange Saturation Transfer for GAG detection (gagCEST) are two of the several methods for GAG assessment. Both methods rely on the endogenous effects. However, sodium imaging suffers from low sensitivity and requires specialized hardware. GagCEST is a new method still in the validation phase. Both methods were implemented on the clinical 3T scanner for the purpose of the validation of the techniques and the correlation between GAG state in-vivo as assessed using the two methods. 2985. Detection of Glycosaminoglycans Using Positive CEST Approach Elena Vinogradov1, Robert E. Lenkinski1 1Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States Chemical Exchange Saturation Contrast utilizes selective presaturation of a small pool of exchanging protons and is manifested in the decrease of the free water signal. Recently, CEST method has been applied successfully to detect glycosaminoglycans (GAG) in cartilage. CEST contrast is negative, resulting in decreased signal from areas with high agent (GAG) concentration. An alternative scheme, positive CEST (pCEST), results in the background suppression and positive contrast when signal is increased due to the presence of the exchanging agent. Here we evaluate application of the pCEST to detect GAG in solutions and ex-vivo samples. Wenbo Wei1, Guang Jia1, Steffen Sammet1, Peter Wassenaar1, Jinyuan Zhou2, Michael Knopp1 1Department of Radiology, The Ohio State University, Columbus, OH, United States; 2Department of Radiology, Johns Hopkins University, Baltimor, MD, United States In this study, dual echo B0 mapping was used in Amide Proton Transfer (APT) imaging for correcting B0 inhomogeneity with fewer data points which will lead to approximately one third of the current scan time and thus higher resolution. CEST spectrum, MTRasym curve and MTRasym (3.5ppm) encoded color maps of the proposed APT method were compared to a conventional method. The proposed method offers a more accurate MTR asym curve shape and a better determination of the water resonance frequency which allows a better MTRasym calculation. Rachel Scheidegger1,2, Elena Vinogradov1,3, David C. Alsop1,3 1Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; 2Health Sciences and Technology, Harvard-MIT, Cambridge, MA, United States; 3Radiology, Harvard Medical School, Boston, MA, United States Off-resonance errors due to magnetic field inhomogeneity are a major challenge for amide proton transfer imaging. Two-pool Bloch equation simulations were used to optimize the timing for pulsed APT imaging with two different subtraction methods. Simulations indicate that the pulse width and interpulse delay as well as the subtraction method used are key factors in optimizing APT for insensitivity to magnetic field inhomogeneity. 2988. Rapid CEST Detection Using EPI Nevin McVicar1, Alex X. Li2, Robert Hudson3, Martyn Klassen2, Robert Bartha1,2 1Medical Biophysics, University of Western Ontario, London, ON, Canada; 2Centre of Functional and Metabolic Imaging, Robarts Research Institute, London, ON, Canada; 3Chemistry, University of Western Ontario, London, ON, Canada An Echo-planar imaging (EPI) pulse sequence was developed to detect CEST paramagnetic contrast. The EPI PARACEST sequence included a 2.5s CEST saturation pulse, followed by a ~ 26ms echo-train. Signal to noise ratio (SNR), CEST effect, and CEST efficiency for EPI CEST sequence were compared to fast spin-echo (FSE) CEST and fast low angle shot (FLASH) CEST in a phantom containing 10 mM Eu3+-DOTAM-Gly-Phe. EPI CEST, provided high temporal resolution and SNR while fully maintaining CEST effect due to the short readout times. Decreasing readout bandwidth had no significant impact on acquisition time or CEST contrast but increased image SNR. 2989. Optimized PARACEST Signal Detection by Echo-Planar Imaging Adrienne Elizabeth Campbell1,2, Alex Li1, Craig Jones3,4, Robert Bartha1 1Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London, Ontario, Canada; 2Centre for Advanced Biomedical Imaging, University College London, London , Greater London, United Kingdom; 3F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, John Hopkins University, Baltimore, MD, United States; 4Centre for Functional and Metabolic Mapping, Robarts Research Institute, University of Western Ontario, London , Ontario, Canada Paramagnetic chemical exchange saturation transfer (PARACEST) contrast agents are being developed for in-vivo MRI. In this study, an accurate in-vivo MRI simulator was developed and used to optimize a time-course Echo-Planar Imaging (EPI) scheme. An 8-shot EPI sequence was simulated for the detection of 100μM and 1mM solutions of Dy3+-DOTAM-GlyLys in vivo. A dynamic EPI scheme, which alternates between a PARACEST EPI sequence that saturates on the bound water pool and a control sequence, was optimized to minimize the SNR requirements for detection. It was determined that EPI schemes may be feasible for PARACEST detection in-vivo. 2990. Optimization of Pulsed Saturation for CEST Imaging in Standard Clinical MR Scanners Benjamin Schmitt1, Moritz Zaiss1, Peter Bachert1 1Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany If CEST imaging is employed in clinical MR systems hardware restrictions and SAR regulations exclude the possibility to generate a steady-state for saturation through CW irradiation. Pulsed saturation, which is used instead, holds disadvantages in preparation time and frequency coverage compared to CW. A narrow frequency coverage while maintaining SAR boundaries as well as short scan times are essential for clinical CEST imaging. We propose an effective pulsed saturation scheme which meets both requirements. The scheme is based on simulations and its effectiveness was verified experimentally. 2991. Detection of Chemical Exchange Saturation Transfer (CEST) Contrast Using Frequency Transfer Joshua Friedman1,2, Michael McMahon1, James Stivers2, Peter Christiaan van Zijl1 1Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 2Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States Currently, CEST compounds are detected using radiofrequency (RF) based saturation transfer followed by asymmetry analysis of the magnetization transfer spectrum. We report an approach that, instead of saturation transfer, employs a series of so-called label-transfer modules (LTMs), in which frequency labeling and consecutive transfer of labeled protons to water is achieved. No asymmetry analysis is needed and exchangeable protons at multiple frequencies can be detected simultaneously through the water proton signal, while maintaining specific frequency information of the individual solute protons. As a first example, the method is applied to a DNA sample and the theory confirmed experimentally. 2992. Chimera Averaging for Robust SSFP Magnetization Transfer Contrast Imaging (MT-Chimera) Christian Stehning1, Peter Boernert1 1Philips Research Europe, Hamburg, Germany Balanced SSFP shows a pronounced magnetization transfer (MT) contrast, which allows for quantitative MT imaging. However, very accurate shimming is needed to cope with offresonances particularly at prolonged TR. A novel approach based on offset averaging of SSFP images with a linear frequency response is investigated. It presents a robust means for MT SSFP imaging with prolonged TR. This approach may be appealing in anatomic regions where susceptibilities cannot be addressed by shimming alone. Sebastian Baier1, Stefan Kirsch1, Lothar R. Schad1 1Department of Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany This work shows a quantitative analysis of magnetization transfer contrast (MTC) enhancement due to intermolecular multiple quantum coherences (iMQC). Therefore a measurement over a wide range of offset frequencies of the MT pulses was performed for different orders of iMQCs. This data was analyzed by fitting both the standard MT 2 Pool model and a modified model including the order of coherence of the iMQCs. Moreover the tissue dependency of the contrast enhancement was investigated.
2994. Theoretical Study of a New Saturation Technique for Magnetization Transfer Experiments Moritz Wilhelm Zaiss1, Benjamin Schmitt1, Bram Stieltjes, Peter Bachert1 1Medical Physics in Radiology, DKFZ, Heidelberg, Germany The best method to evaluate magnetization transfer and chemical exchange transfer are saturation transfer experiments with constant saturation power. Our approach is a varying saturation power depending on the saturation offset. Hereby, the solution of the Bloch-McConnell equations changes fundamentally. Theoretical studies show that off-resonant pools can be isolated from the water resonance while the intensity of the transfer effect remains unchanged. Numerical simulations with pulsed saturation returned similar results. So, the application on clinical scanners with pulsed saturation promises a more robust way of measuring and evaluating z-spectra than common z-spectrum asymmetry analysis. 2995. Preliminary Investigation of the Use of Parallel RF Transmission in MTR Measurement at 3.0T Rebecca Sara Samson1, Matthew Clemence2, Xavier G. Golay3, Claudia A M Wheeler-Kingshott1 1NMR Unit, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom; 2Philips Clinical Science Group, Philips Healthcare, Guildford, United Kingdom; 3NMR Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom RF B1 transmit field non-uniformity, caused primarily by skin depth and dielectric resonance effects, is a large source of error in quantitative MR measurements made at 3.0T. We investigated the possibility that B1 errors could be reduced using dual transmission by measuring the MTR and B1 with and without dual transmission. We present preliminary data acquired on three healthy subjects indicating that it may be possible to reduce inter-subject variation in MTR histogram peak locations via the use of dual transmission at 3.0T. This could be an important consideration when designing future long-term clinical studies using quantitative MRI outcome measures.
2996. Orientation Dependence of Magnetization Transfer in Human White Matter. Dirk K. Müller1, André Pampel1, Harald E. Möller1 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany We present an investigation of the dependence of quantitative magnetization transfer (qMT) on fibre orientation. QMT parameters obtained from experiments using pulsed off-resonance irradiation were correlated to the orientation of the diffusion tensor obtained from DTI data. In particular, we observed a correlation between the fiber orientation with respect to B0 and the transverse relaxation rate of the semi-solid pool (T2b). 2997. Quantification of the Magnetization Transfer Phenomenon in the Human Head at 7T Olivier E. Mougin1, Penny A. Gowland1 1Sir Peter Mansfield Magnetic Resonance Centre, School of Physics & Astronomy,University of Nottingham, Nottingham, Nottinghamshire, United Kingdom Magnetization Transfer and related effects such as CEST are important sources of contrast in MRI. Sensitivity and increase spectral resolution make possible the measurement of MT effects at 7T in vivo. We used pulsed saturation with Turbo Field Echo readout with a range of saturation offset frequencies on the approach to steady-state, providing data that can be used to measure MT parameters at 7T in a reasonable imaging time at a resolution of 1.25mm isotropic. Ives R. Levesque1, John G. Sled2, G Bruce Pike1 1Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada; 2Mouse Imaging Centre, Hospital For Sick Children, Toronto, Ontario, Canada A method is presented for the selection of an optimal acquisition scheme for quantitative magnetization transfer imaging using pulsed off-resonance saturation. This method is based on the iterative reduction of a discrete sampling of the Z-spectrum. In vivo results demonstrate that optimized sampling improves parameter map quality and longitudinal reproducibility. The reduction method avoids clustering and repeated points, an attractive feature for the purpose of MT model validation. The optimal number of MT weightings is also investigated. Becky Ilana Haynes1, Nick G. Dowell1, Paul S. Tofts1 1Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, Brighton, United Kingdom Repeatability of MTR and ADC brain histograms of healthy volunteers in our centre showed disturbingly large differences, even though the scanner was producing high quality images. Such instrumental variation could mask small between-group differences in a cross-sectional study, and increase the number of participants needed to see an effect. Repeat scans in phantoms and healthy controls highlighted the variability and showed when the problem had been fixed. Our current normal standard deviations are at the lower end of the published range. Ongoing QA for quantitative studies should include explicit measurement of short- and long-term repeatability in controls. Hunter R. Underhill1,2, Chun Yuan1, Vasily L. Yarnykh1 1Radiology, University of Washington, Seattle, WA, United States; 2Bioengineering, University of Washington, Seattle, WA, United States In this study, we compare strategies for the time-efficient acquisition of the bound pool fraction in the in vivo human brain at 3.0 T. The bound pool fraction can be accurately estimated using only two off-resonant magnetization transfer data points by applying appropriate, field-strength specific constraints to the transfer rate constant and transverse relaxation parameters. In so doing, whole-brain, three-dimensional, high-resolution f-maps can be obtained in a clinically acceptable scan time. Simulations demonstrate that the effects of parameter constraints induce minimal error in determining f in grey matter, white matter and multiple sclerosis lesions. Julien Flament1, Benjamin Marty1, Céline Giraudeau1, Sébastien Mériaux1, Julien Valette1, Christelle Médina2, Caroline Robic2, Marc Port2, Franck Lethimonnier1, Gilles Bloch1, Denis Le Bihan1, Fawzi Boumezbeur1 1NeuroSpin, I²BM, Commissariat ą l'Energie Atomique, Gif-sur-Yvette, France; 2Guerbet, Research Division, Roissy-Charles de Gaulle, France LipoCEST are a new class of contrast agents for CEST-MRI which provide a tremendous amplification factor but suffer from a quite small chemical shift (2-28 ppm) compared to paramagnetic complexes. Consequently, their detection in vivo is hampered by endogenous Magnetization Transfer contrast. It is therefore important to separate specific LipoCEST signal from endogenous background coming from macromolecules. Thus in this study, we propose to characterize water exchange processes using a five-site model by measuring and fitting the Z-spectrum of each tissular compartment of mouse brain in order to achieve quantitative CEST imaging with LipoCEST contrast agents. 3002. Detection of Proton Chemical Exchange Between Metabolites and Water Using T1ρ MRI Feliks Kogan1, Walter Witschey1, Keijia Cai1, Mohammad Haris1, Ravinder Reddy1 1Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States Imaging of chemical exchange processes is important as it allows for quantification of specific metabolites. In this study, we developed a new method based on T1ρ MRI to create image contrast and quantify the exchange of protons between metabolites and water. We showed that this method is responsive to changes in concentration as well as pH. The sensitivity of this technique scales quadratically with static magnetic field and becomes much more valuable as high field magnets become more widely available clinically. Feliks Kogan1, Walter Witschey1, Keijia Cai1, Mohammad Haris1, Ravinder Reddy1 1Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States Recent work on imaging chemical exchange processeshas been focused on exploitingchemical exchange saturation transfer (CEST). T1ρ imaging is another imaging technique which depends on chemical exchange which can be used to image metabolites based on their proton exchange properties. In this study, we compared the sensitivities of these two techniques for measuring metabolites based on proton exchange. We observed that at 7T, T1ρ imaging has a higher sensitivity to exchanges processes compared to that of CEST. Joonas Arttu Autio1,2, Tao Jin3, S-G Kim3,4, Takayuki Obata1 1Department of Biophysics, National Institute of Radiological Sciences, Chiba, Japan; 2Department of Neurobiology, University of Kuopio, Kuopio, Finland; 3Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States; 4Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, United States Previous study has demonstrated an indirect MRI detection of hydroxyl protons of small metabolites via chemical exchange saturation transfer. We used an on-resonance spin-locking (SL) pulse to detect proton exchange for hydroxyl-, amide- and amine-phantoms, and a protein sample. Analysis of spin-lattice relaxation rate in the rotating frame dispersion over a range of SL B1 fields, resulted in robust estimates for intermediate proton exchange rates and exchangeble proton site populations. Our results suggest that SL technique with on-resonance irradiation is not sensitive to very slow exchange, but may be more suited for quantitative study in the intermediate exchange regime. 3005. A Fast, Quantitative T1ρ Imaging Method Timo Liimatainen1, Olli Gröhn2 1Department of Biotechnology and Molecular Medicine, University of Kuopio, Kuopio, Finland; 2Department of Neurobiology, University of Kuopio, Kuopio, Finland A pulse sequence based on gradient echo design was modified to include four hyperbolic secant pulses, following by a signal acquisition. This was repeated four times to obtain a T1ρ weighted signal intensity curve with incrementally increasing spin-lock time for single phase encoding step. T1ρ relaxation times were compared between developed method and spin echo readout with a T1ρ preparation pulse train in mice brains. Similar T1ρ values were obtained with both methods. The developed method allows acquisition of several incremented spin-lock times within one repetition time enabling faster quantization of T1ρ and/or decreased specific absorption rates. Silvia Mangia1, Michael Garwood1, Steen Moeller1, Dennis Sorce1, Kamil Ugurbil1, Shalom Michaeli1 1CMRR - Dept. of Radiology, University of Minnesota, Minneapolis, MN, United States In the present work we investigate the different sensitivity to exchange processes generated at 4T by a variety of preparation pulses. To this aim, we quantitatively analyzed images from the human brain acquired by preparing magnetization with an off-resonance hard pulse, to exploit the so-called magnetization-transfer effect, or by preparing magnetization with a series of adiabatic pulses with different modulation functions, to exploit adiabatic rotating frame relaxation mechanisms. Results demonstrate that the two approaches are sensitive to completely different regimes of exchange, thus providing complimentary information to characterize the tissue. 3007. Measuring T1ρ Changes Related to Acidosis and Alkalosis Hye Young Heo1, Nader Dahdaleh1, Daniel Thedens1, Bradley Bolster2, John Wemmie1, Vincent Magnotta1 1University of Iowa, Iowa City, IA, United States; 2Siemens Healthcare, Rochester, MN, United States The purpose of this study is to determine the ability of magnetic resonance (MR) imaging to assess regional pH levels. Both phantom and mouse models were used to evaluate pH sensitive changes in T1ρ imaging. A linear relationship was observed between T1ρ time and pH. In the mouse model, widespread increases in T1ρ times during CO2 inhalation were found consistent with the expected acidosis, whereas reduced T1ρ times during HCO3- injection were found to be consistent with the expected alkalosis. Gerald Matson1, Hui Liu1 1CIND, Veterans Affairs Medical Center, San Francisco, CA, United States Magnetization transfer (MT) effects in the human brain occur when there is magnetization transfer between the free and bound water pools associated with gray and white matter. These MT effects can become significant, particular when longer excite pulses are used, for example, to induce uniform tip angles in the presence of non-uniform RF fields. Therefore, we developed a simulation program written in Matlab to calculate these MT effects, and to simulate the 3D MPRAGE experiment. The simulations show that the MT effects must be taken into account when longer excite pulses are used in the 3D MPRAGE experiment. 7T MRI Thursday 13:30-15:30 Samuel James Wharton1, Richard Bowtell1 1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, United Kingdom Phase images generated using gradient echo techniques at high field show excellent contrast related to variation of magnetic susceptibility across brain tissues. Calculating susceptibility maps from phase data is made difficult by the ill-posed nature of the deconvolution problem which must be solved. Careful conditioning is therefore required. Here, we compare the performance of three conditioning strategies ((i) combination of data acquired at multiple orientations; (ii) k-space thresholding of data acquired at a single orientation; (iii) incorporation of structural information using corresponding modulus data) in the calculation of susceptibility maps from high-resolution phase images of the brain and a phantom. 3010. Basis for Contrast Enhanced T1- Weighted Imaging Using SE at High Field Niravkumar Darji1, Michel Ramm1, Oliver Speck1 1Department Biomedical Magnetic Resonance, Institute for Experimental Physics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany Aim of this study was to reduce fat signal without using fat saturation pulse. This task was achieved by modification of RF pulse in SE sequence. Different bandwidth of the refocusing pulse allows suppression of fat signal without increased SAR in high resolution SE imaging. The reduced fat signal with longer refocusing pulse duration is evident from in-vivo experiments. 3011. Adiabatic Magnetization Preparation Pulse for T2-Contrast at 7 Tesla Priti Balchandani1, Daniel Spielman1 1Radiology, Stanford University, Stanford, CA, United States T2-weighted sequences such as Fast Spin Echo are highly susceptible to the B1-inhomogeneity and are SAR-intensive at 7T. We present an alternative method to obtain T2-contrast at 7T which utilizes an adiabatic magnetization preparation (AMP) pulse. The AMP pulse is a 0° BIR-4 pulse with delays inserted between segments to introduce T2-decay. Phantom and in vivo experiments show that the AMP pulse provides more uniform SNR and T2-contrast over the excited slice. The AMP pulse is suitable for use in a volumetric fast gradient echo sequence. 3012. Comparison of Reduced FOV Techniques for High Resolution Imaging at 7T Christopher Joseph Wargo1, Marcin Jankiewicz1, John C. Gore1 1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States High-resolution MR imaging benefits from ultra-high field strength such as at 7T due to improvement in signal, but requires acquisition of a large number of voxels. This increases the scan duration, and thus field and time dependent artifacts, and reduces temporal resolution for functional studies. Reduction of the FOV enables scan times to be shortened, but introduces tradeoffs between SNR, scan efficiency, SAR, and image artifacts. In this abstract, we compare a subset of selective excitation approaches including STEAM, PRESS, OVS, and spectral spatial pulses, for reduced-FOV resolution improvement in phantoms using a human 7T system. 3013. Towards the Accurate and Precise Assessment of SNR in Vivo at 7T Josef Habib1,2, Dorothee P. Auer1, Richard W. Bowtell2 1Academic Radiology, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; 2Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom The Signal-to-Noise ratio (SNR) is a fundamental and critical data quality measure in MRI, with several investigations dedicated to devising and validating optimized measurement techniques. While the introduction of higher field strength MRI systems is expected to impact attainable SNR levels, this study shows that the prevalent technique for measuring SNR in vivo performs sub-optimally at 7 Tesla, due to artifacts presumably caused by the increased sensitivity to subject or physiological motion. Here we propose the use of an alternative measurement technique for increased robustness, after quantitatively evaluating its precision and accuracy. Ludovic de Rochefort1, Martine Guillermier1, Diane Houitte1, Marion Chaigneau1, Philippe Hantraye1, Vincent Lebon1 1MIRCen, I2BM, DSV, CEA, Fontenay-aux-Roses, France Susceptibility-induced magnetic field and chemical shift increase image distortion at high field. In a 2D FSE sequence, increasing the bandwidth to limit these artifacts implies degrading SNR by reducing the ratio of the observation time (TO) per unit time rapidly reaching SAR and gradient duty cycle limitations. We propose to replace the readout within the 180 pulses by a train of gradient echoes with a larger bandwidth and the same TO. It is shown in vivo on rat brain that susceptibility induced distortions are suppressed by this approach while preserving SNR and contrast. Phase Imaging Monday 14:00-16:00 3015. Removing Air-Tissue Artifacts in Phase Images by Modulating the Air Susceptibility José P. Marques1,2, Rolf Gruetter1,3 1Centre d'Imagerie BioMédicale, EPFL, Lausanne, Vaud, Switzerland; 2Department of Radiology, University of Lausanne, Lausanne, Vaud, Switzerland; 3Department of Radiology, Universities of Lausanne and Geneva, Switzerland In this work, the susceptibility of air was varied by changing its oxygen fraction. Such a variation of the air susceptibility allowed to exclusively map the contribution from oxygen towards the measured frequency shift maps in phantoms and volunteers. This allowed removal of a significant part of the observed frequency shift around air-water interfaces, making the frequency shift maps more specific to their rich tissue contrast. 3016. Myelin as a Primary Source of Phase Contrast Demonstrated in Vivo in the Mouse Brain Nicoleta Baxan1, Laura-Adela Harsan1, Iulius Dragonu1, Annette Merkle1, Juergen Hennig1, Dominik von Elverfeldt1 1Diagnostic Radiology, Medical Physics, University Hospital Freiburg, Freiburg, Germany While most of MRI studies are focused on the magnitude data, the phase contrast has only recently proved its ability to improve the contrast to noise in high-resolution images at high-field strength. The origin of phase contrast between white matter (WM) and gray matter (GM) has been widely discussed; several sources were suggested including paramagnetic blood deoxyhemoglobin, tissue iron concentrations, water-macromolecules exchange or tissue myelin content. In the present study we examine the contribution of tissue myelin content to the phase contrast by exploiting the frequency shift variation in a chronic model of cuprizone induced demyelination. 3017. Phase Imaging: A Novel Tool for Myelin Quantification. Gregory A. Lodygensky1, Rajika Maddage2, Alexandra Chatagner3, Petra S. Hüppi3, José Pedro Marques2, Stephane V. Sizonenko3, Rolf Gruetter2 1Pediatrics, Pediatric and Neonatal ICU, University of Geneva, Geneva 14, Switzerland; 2Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 3Pediatrics, Division of Child Growth & Development, University of Geneva, Geneva, Switzerland Phase imaging may allow fast and accurate myelin quantification at high resolution. A quantitative MRI-histology study of myelination on the developing rat brain. Markus Nikola Streicher1, Andreas Schäfer1, Bibek Dhital1, Dirk Müller1, Robin Martin Heidemann1, Andre Pampel1, Dimo Ivanov1, Robert Turner1 1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany We implemented a novel spin-echo EPI sequence that can acquire phase images of different chemically-shifted protons at the same slice positions. Chemical selection was achieved by applying different slice-select gradient amplitudes for excitation and refocusing RF pulses, and phase sensitivity was obtained using an asymmetric EPI readout. MR Thermometry was then performed on a mixture of water and dimethyl sulfoxide (DMSO), which has a proton chemical shift of -2 ppm from water. The two compounds were then imaged alternately, water for temperature sensitivity and DMSO to monitor field changes. Fat can also be selectively imaged as a reference compound. 3019. A Novel Method of Increasing the Contrast to Noise Ratio of Phase Images Using Balanced SSFP Jongho Lee1, Masaki Fukunaga1, Jeff H. Duyn1 1Advanced MRI/LFMI/NINDS, National Institutes of Health, Bethesda, MD, United States A new method of generating phase contrast is proposed. Using balanced SSFP sequence a significant contrast to noise ratio improvement was achieved. Using this method, the line of Genari in the visual cortex was shown at 3 T in a high resolution. SSFP Hall B Tuesday 13:30-15:30 Garry Liu1, Venkat Ramanan2, Graham Wright1 1University of Toronto, Toronto, ON, Canada; 2Sunnybrook Health Sciences Centre, Toronto, ON, Canada Fat signal suppression is essential for MR angiography. In this work, we present a generalized design of a 1-2-1 binomial pulse SSFP (BP-SSFP) sequence, and the trade-off between TR reduction, water SNR, and water/fat CNR. We apply our method to achieve a short scan time, provide steady-state fat suppression, maintain high SNR, and restrict banding artifacts for peripheral MR angiograms. Way Cherng Chen1, Rob H Tjissen1, Chrsitopher T Rodgers2, Jamie Near1, Karla L Miller1 1FMRIB, University of Oxford, Oxford, United Kingdom; 2OCMR, University of Oxford, Oxford, United Kingdom Steady-state free precession (SSFP) is characterized by strong signal dependence on resonance frequency often described by the SSFP frequency profile.This profile has a well known symmetric shape in a homogeneous voxel but it becomes asymmetric in an inhomogeneous voxel. The SSFP profile can be modeled as the convolution of the homogeneous profile with the frequency distribution. In this study, CSI lineshape from normal white matter tracts was convolved with the homogeneous profile obtain a predicted SSFP asymmetry profile. The predicted SSFP asymmetry profile was found to be in good agreement with the measured SSFP asymmetry profile.The ability of SSFP profile to amplify small frequency shifts makes it a promising contrast mechanism for probing tissue microstructures. 3022. Off-Resonance Banding Maps with Low Flip Angle Balanced Steady-State Free Precession Abbas Nasiraei Moghaddam1,2, J Paul Finn1, Daniel B. Ennis1 1Radiology, UCLA, Los Angeles, CA, United States; 2Bioengineering, Caltech, Pasadena, CA, United States Balanced steady-state free precession (bSSPF) is widely used for clinical exams. The off-resonance sensitivity, in particular, limits the use of bSSFP for clinical exams at field strengths greater than 1.5T. Herein we highlight the signal characteristics of the bSSFP pulse sequence for high and low flip angles in regions that are on- and off-resonance. Low flip angle bSSFP can be used to map off-resonance bands with bright image contrast. This is useful for discriminating image features that have low bSSFP signal intensity when high flip angles are employed and regions of off-resonance. 3023. Radio Frequency (B1) Field Mapping at 7T Using 3D SE/STE EPI Technique Antoine Lutti1, Chloe Hutton1, Jorg Stadler2, Oliver Josephs1, Oliver Speck3, Claus Tempelmann4, Johannes Bernarding5, Nikolaus Weiskopf1 1Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom; 2Special Lab Non-Invasive Brain Imaging, Leibniz Institute for Neurobiology, Magdeburg, Germany; 3Dept. Biomedical Magnetic Resonance, Institute for Experimental Physics , Otto-von-Guericke University, Magdeburg, Germany; 4Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany; 5Institute for Biometry and Medical Informatics, Faculty of Medicine, Otto-von-Guericke-University, Magdeburg, Germany Spatial inhomogeneities in the radio-frequency (RF) field (B1) increase with field strength affecting quantification and image contrast. Fast and robust whole-brain B1 mapping methods are therefore essential to correct for B1 inhomogeneities at ultra-high fields. Here we optimize a SE/STE 3D EPI method for rapid B1 mapping at 7T, addressing severe off resonance effects and reducing sensitivity to transverse coherence effects. We demonstrate the robustness of this B1 mapping technique and illustrate its accuracy by correcting for B1 inhomogeneities in T1 maps. 3024. Transient Balanced SSFP Imaging with Increased Signal by Variable Flip Angles Pauline W. Worters1, Brian A. Hargreaves1 1Stanford University, Stanford, CA, United States This work presents a method for calculating variable flip angles for balanced (or fully refocused) steady state free precession (bSSFP) acquisition to generate echoes at predefined amplitudes. The main advantage is to allow for transient stage imaging with minimal artifacts and with increased signal. The variable flip angle calculation was applied to provide temporally uniform echo amplitudes. A non-contrast enhanced MRA acquisition, inflow inversion recovery (IFIR) bSSFP, was used to demonstrate the method; the resulting angiograms show improved signal and small vessel depiction. 3025. Analysis of the Transient Phase of Balanced SSFP with Non-Continuous RF for Cardiac Imaging Glenn S. Slavin1 1Applied Science Laboratory, GE Healthcare, Bethesda, MD, United States An analytical expression for the transient phase of a segmented, ECG-gated, non-continuous-RF, balanced SSFP sequence is presented. The results provide a means for true quantification of T1 and T2 for Look-Locker-based cardiac acquisitions. 3026. Region-Growing Reconstruction for Large-Angle Multiple-Acquisition BSSFP Brady Quist1, Brian A. Hargreaves2, Glen R. Morrell3, Garry E. Gold2, Neal K. Bangerter1 1Department of Electrical & Computer Engineering, Brigham Young University, Provo, UT, United States; 2Department of Radiology, Stanford University, Stanford, CA, United States; 3Department of Radiology, University of Utah, Salt Lake City, UT, United States A novel method for simultaneously suppressing fat and reducing bSSFP banding artifacts in the presence of field inhomogeneity was recently presented, called large-angle multiple-acquisition (LAMA) bSSFP. LAMA bSSFP requires the acquisition of two phase-cycled SSFP acquisitions and a field map, although previous work has suggested that an intelligent region-growing algorithm could replace field-map acquisition. In this work, we present such a region-growing algorithm, and demonstrate that LAMA bSSFP can perform effectively without the acquisition of a field map. Results are presented in the lower leg of a normal volunteer. Keigo Kawaji1, Thanh D. Nguyen2, Beatriu Reig2, Pascal Spincemaille2, Priscilla A. Winchester2, Martin R. Prince2, Yi Wang1,2 1Biomedical Engineering, Cornell University, Ithaca, NY, United States; 2Radiology, Weill Cornell Medical College, New York, NY, United States T2prep Inversion Recovery (T2IR) is a magnetization preparation technique that combines two preparations: T2prep and Inversion Recovery, in order to provide both T1 and T2 contrasts. Subsequently, T2IR provides flow-insensitive global black-blood suppression suited for slow flow at the expense of SNR, being suitable for 3D volumetric black-blood imaging of vessel walls where slow blood flow is observed. In this study, we examined the performance of using a T2IR preparation in both FSE and SSFP sequences to image a large 3D coronal volume (20cm x 20cm x 5.2cm) at a submillimeter isotropic spatial resolution of 0.8mm. 3028. Dark Blood BSSFP Cardiac MRI Using HEFEWEIZEN Karan Dara1, Jamal J. Derakhshan1, Jeffrey L. Duerk1, Jeffrey L. Sunshine2, Mark A. Griswold1 1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; 2Department of Radiology, University Hospitals of Cleveland, Cleveland, OH, United States T2-weighted dark blood prepared TSE sequences are commonly used to image cardiac pathology. These methods often suffer from motion artifacts due to their long acquisition times. Here we apply a new, fast, high SNR, dark blood prepared segmented TrueFISP sequence (HEFEWEIZEN) for cardiac imaging in which some TR blocks are replaced by spatially selective saturation pulses for out-of-slice signals. This directionally suppresses bright blood flow (>65%) in the cardiac ventricles with some stationary tissue signal suppression offering a potential application to cardiac imaging. 3029. Banding Artifact Reduction in 2D CINE Balanced SSFP at 3.0 T Using Phase-Cycling and k-T BLAST Ute Kremer1, Fabian Hezel2, Gabriele A. Krombach1, Thoralf Niendorf2,3 1Department of Diagnostic Radiology, University Hospital, RWTH Aachen, Aachen, Germany; 2Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine (MDC), Berlin, Germany; 3Charité, University Medicine, Berlin, Germany This work proposes to combine phase-cycled bSSFP with k-t BLAST to overcome the scan time penalty of multiple-acquisition bSSFP while still eliminating off-resonance induced banding artifacts at 3.0 T. Acquisitions were conducted using four-fold accelerated k-t BLAST and three phase-cycles. For comparison conventional bSSFP was obtained and endocardial border sharpness (EBS) assessment was performed. In theory omitting one of the four standard phase-cycles disturbs the off-resonance profile's flatness, however for in vivo imaging it yielded excellent banding reduction and improved the mean EBS. Accelerated, phase-cycled bSSFP imaging promises to extend the capabilities of routine CINE imaging at (ultra)high fields. Rare & Turbo Spin Echo Hall B Wednesday 13:30-15:30 3030. Reduced SAR with Combined Acquisition Technique (CAT) Hybrid Imaging Sequence at 7 Tesla Morwan Choli1, Felix A. Breuer1, Daniel Neumann2, Michael Bock3, Claudia M. Hillenbrand4, Ralf B. Loeffler4, Peter M. Jakob2,5 1Research Center Magnetic Resonance Bavaria e.V (MRB) , Wuerzburg, Germany; 2Dept. of Experimental Physiks 5, University of Würzburg, Wuerzburg, Germany; 3Department of Medical Physics in Radiology, , German Cancer Research Center (dkfz), Heidelberg, Germany; 4Department of Radiological Sciences, Division of Translational Imaging Research, Memphis, TN, United States; 5Research Center Magnetic Resonance Bavaria e.V (MRB), Wuerzburg, Germany Higher field strength comes along with increase of the deposited SAR energy. Important imaging sequences like TSE with numerous refocusing pulses are only exercisable with limitations of the parameters at the expense of image quality to protect patients. In this work it is shown that it is possible to obtain high resolution in vivo images on a 7T scanner with an almost equal signal behavior in a combined acquisition technique (CAT) hybrid sequence consisting of a TSE module and an EPI module with SAR saving of 27%. Masami Yoneyama1, Masanobu Nakamura1, Takashi Tabuchi1, Atsushi Takemura2, Junko Ogura1 1Medical Satellite Yaesu Clinic, Chuo-ku, Tokyo, Japan; 2Philips Electronics Japan, Ltd., Minato-ku, Tokyo, Japan T1 weighted 3D VRFA-TSE sequence is decreasing flow artifacts by sequence-endogenous flow-void enhancement. But, T1 contrast becomes sub-optimal with the long echo train and pseudo steady-state effects. We propose a new scheme of more T1-optimized black-blood 3D TSE pulse sequence with low refocusing flip angles. Volunteer experiments were acquired in 3D low refocusing flip angle TSE (LOWRAT) using a 3.0T imager. The optimal parameter for T1-optimized black-blood imaging was low excitation flip angles, low refocusing flip angles, NPHA pseudo steady-state preparation, short ETL, best echo number for K-space center=2nd echo, and shortest TR. Contrast behavior of 3D LOWRAT T1W was similar to that of 2D SE. This optimal sequences can be used for 3D volumetric T1 weighted black-blood imaging.
Robert Marc Lebel1, Alan W. Wilman1 1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada At high field strengths, fast spin echo is a SAR constrained procedure; parameter concessions are required to enable its use. Typical modifications include elongated RF pulses and reduced refocusing angles. We present an SNR analysis investigating the effects of reduced angles (lower signal) and longer RF pulses (less readout time) and present a reliable method for rapidly selecting these parameters to optimize the SNR for a given target power level. 3033. Reduced SAR with BASE Sequence at 7 Tesla Daniel Neumann1, Morwan Choli2, Martin Blaimer2, Michael Bock3, Felix Breuer2, Peter M. Jakob4 1Experimental Physics 5, University of Würzburg, Würzburg, Germany; 2Experimental Physics 5, Research Center Magnetic Resonance Bavaria (MRB), Würzburg, Germany; 3Department of Medical Physics in Radiology, German Cancer Research Center (dkfz), Heidelberg, Germany; 4Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany The step towards higher magnetic fields on the one hand provides a stronger NMR signal while on the other hand SAR is significantly increased in comparison with standard clinical scanners. Therefore the application of sequences using many refocusing pulses such as TSE can be difficult. In this work we examine the potential of the BASE sequence to obtain high resolution images at 7T. BASE is a combination of BURST and multiple refocusing pulses. However, compared to TSE, there are a lower number of pulses and therefore SAR could be reduced by a factor of four. 3034. Whole-Brain FLAIR Using 3D TSE with Variable Flip Angle Readouts Optimized for 7 Tesla John W. Grinstead1, Oliver Speck2, Dominik Paul, Lisa Silbert3, Louis Perkins3, William Rooney3 1Siemens Healthcare, Portland, OR, United States; 2Biomedical Magnetic Resonance, Otto-von-Guericke-University, Magdeburg, Germany; 3Oregon Health and Science University Routine FLAIR uses a 2D inversion-recovery turbo spin echo pulse sequence having many high-SAR RF pulses, allowing only a few slices to be acquired at 7 Tesla. Recent work demonstrated the feasibility of using 3D IR-TSE with a T2-prepared IR and a reduced flip angle readout of 70 degrees to perform whole brain FLAIR at 7 Tesla for the first time. The present work extends this approach with a variable flip angle readout optimized for the T1 and T2 values of brain tissues at 7 Tesla to further improve the SAR, contrast, and SNR performance. 3035. Inversion of a Non-CPMG Fast Spin Echo Train. Patrick H. Le Roux1 1Applied Science Lab, GE Healthcare, Palaiseau, IDF, France The non-CPMG sequence permits to acquire MR signal in the Fast Spin Echo mode even when the CPMG (Carr Purcell Meiboom Gill) phase conditions cannot be fulfilled. It consists in a quadratic phase modulation of the refocusing pulses train, preceded by a suitable preparation period. It turns out that this sequence of RF pulses can be readily inversed permitting a perfect Driven Equilibrium scheme to be applied. Guobin Li1, Christoph Sauerbier2, Dominik Paul3, Weijun Zhang1, Qiang He1, Marc Beckmann1, Lars Lauer3 1Siemens Mindit Magnetic Resonance Ltd., Shenzhen, Guang Dong, China; 2Hochschule Furtwangen University, Germany; 3Siemens Medical Solutions, Erlangen, Germany Slab selection by the dual echo-spacing technique in SPACE with non-selective refocusing pulses needs averaging with phase cycling ans is sensitive to chemical shift artifacts during excitation. A new technique, VERSE-SPACE is presented in this abstract to provide faster acquisition speed and better slab profile than the previous technique. Guobin Li1, Dominik Paul2, Weijun Zhang1, Tallal Charles Mamisch3, Qiang He1, Marc Beckmann1, Lars Lauer2 1Siemens Mindit Magnetic Resonance Ltd., Shenzhen, Guang Dong, China; 2Siemens Medical Solutions, Erlangen, Germany; 3Department of Orthopaedic Surgery, Inselspital, University of Berne, Bern, Switzerland In Single Slab SPACE, relative short TR and long echo train have to be used to reduce the total acquisition time into clinical acceptable range at the cost of the degradation in contrast purity and SNR, especially in PDw imaging. A new Multi-Slab SPACE is presented here to further increase the sampling efficiency, and then provides more flexibility to use longer TR and shorter echo train acquisition compared to Single Slab SPACE. 3038. Fast Spin-Echo Imaging of Inner Field-Of-Views Using 2D-Selective RF Excitations Jürgen Finsterbusch1,2 1Department of Systems Neuroscience , University Medical Center Hamburg-Eppendorf, Hamburg, Germany; 2Neuroimage Nord, University Medical Centers Hamburg-Kiel-Lübeck, Hamburg-Kiel-Lübeck, Germany Fast spin-echo imaging suffers from image blurring if a large number of echoes per excitation (turbo factor) is used and, in particular at higher magnetic fields, from SAR limitations. Focussing the field-of-view to a small inner volume reduces the number of required echoes considerably and thus ameliorates blurring and RF deposition. This is demonstrated in phantoms and the human brain at 3T using blipped-planar 2D-selective RF excitations. Thereby, the unwanted side excitations were positioned in the dead corner between the slice stack and the image section in order to minimize the duration of the 2DRF excitations without saturating neighbored sections. Echo Planar Imaging: New Acquisition Approaches Hall B Thursday 13:30-15:30 Thomas Sushil John1, Dwight George Nishimura2, John Mark Pauly2 1Electrical Engineering , Stanford University, Stanford, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States A common solution to correct for ghosting in interleaved echo planar imaging (EPI) is to employ echo time shifting (ETS). Although ETS corrects for ghosting in a robust, non-iterative, and automatic manner, it does so at the expense of increasing total scan time. In this work, a simple, yet effective scheme to increase the efficiency of ETS is proposed. Using the proposed technique, shorter scan times are possible when the in-plane resolution is fixed. Alternatively, the proposed scheme can acquire higher resolution images when total scan time is fixed. 3040. Non-Uniform Density EPI Acquisition Improves the SNR of Smoothed MR Images Lars Kasper1,2, S. Johanna Vannesjö1, Maximimilian Häberlin1, Christoph Barmet1, Klaas Enno Stephan2,3, Klaas Paul Prüssmann1 1University and ETH Zurich, Institute for Biomedical Engineering, Zurich, Switzerland; 2Institute for Empirical Research in Economics, University of Zurich, Laboratory for Social and Neural Systems Research, Zurich, Switzerland; 3 Institute of Neurology, University College London, Wellcome Trust Centre for Neuroimaging, London, United Kingdom Smoothing MR-images is a common preprocessing step in areas like functional MRI to improve signal as well as noise characteristics of the images and facilitate inter-subject comparison. We present how an EPI-acquisition scheme (1.5 mm resolution) whose density is specifically tailored to match an image smoothing kernel improves the SNR of the finally smoothed images. Furthermore, this shows the opportunity to assign differing spatial properties to signal and noise contributions within an MR image. Because these non-uniform trajectories differ from common MR gradient demands, we relied on actually measured trajectories for our reconstructions, using an NMR field monitoring setup. Andrew Scott Nencka1, Daniel L. Shefchik1, Eric S. Paulson2, Andrzej Jesmanowicz1, James S. Hyde1 1Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 2Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI, United States Pulse sequences which acquire trains of echoes face an inherent limit in resolution due to intra-acquisition decay. In gradient echo sequences, often used in functional studies, T2* decay leads to an increased point spread function in the phase encoding direction due to the lower effective bandwidth in that direction during data acquisition. In this abstract, we illustrate that the desirable T2 weighting associated with gradient echo sequences may be preserved with an asymmetric spin echo, and that acquisitions on the ascending edge of the spin echo yield point spread functions which are reduced in the phase encoding direction. This effect comes from the competing T2 rephrasing and T2 decay leading up to the formation of the spin echo. Matching the effective echo time on the ascending and descending sides of the spin echo can yield varying image contrast in vivo due to true T2 decay, thereby affecting the perceived smoothness of the reconstructed image. MRI Sequence Optimisation Hall B Monday 14:00-16:00 Warren S. Warren1, Rosa Tamara Branca2 1Chemistry/CMBI, Duke University, Durham, NC, United States; 2Chemistry, Duke University, Durham, NC, United States A recent quantum computing paper analytically derived optimal pulse spacings for a multiple spin echo sequence which differ dramatically from the conventional, equal pulse spacing of a Carr-Purcell-Meiboom-Gill (CPMG) sequence. Here we show that this UDD sequence has advantages for MR of tissue, where diffusion in microstructured environments leads to fluctuating fields on a range of different timescales. Both in excised tissue and in a live mouse tumor model, optimal UDD sequences produce different contrast than do CPMG sequences, with substantial enhancements in most regions. This provides a new source of endogenous contrast and enhances sequences which are currently T2-limited. Jian Zhu1,2, Axel Bornstedt1, Vinzenz Hombach1, Alexander Oberhuber3, Genshan Ma2, Naifeng Liu2, Volker Rasche1 1Department of Internal Medicine II, University Hospital of Ulm, Ulm, Germany; 2Department of Cardiology, Zhongda Hospital, Southeast University, Nanjing, China; 3Department of Thorax and Vascular Surgery, University Hospital Ulm, Ulm Spin-echo and multi-spin echo sequences are still the gold standard for generation of a T2 weighted image contrast. A major drawback of this technique rises from the long repetition times required for achieving sufficient recovery of the longitudinal magnetization, which cause long acquisition times especially in high-resolution volumetric imaging. In this study, the use of a fast gradient echo sequence with T2 preparation is investigated for generating a T2 weighted image contrast similar to a multi-spin echo approach, but with an up to 8-fold reduction of the acquisition time. Dan Rettmann1, Manojkumar Saranathan1, James Glockner2 1Applied Science Lab, GE Healthcare, Rochester, MN, United States; 2Radiology, Mayo Clinic, Rochester, MN, United States Dynamic contrast enhanced MRI (DCEMRI) and MR angiography (MRA) are both beset by the conflicting requirements of spatial and temporal resolution. Various schemes have been proposed and evaluated for high spatio-temporal resolution MR imaging which incorporate combinations of partial Fourier imaging, sub-sampling, view sharing and parallel imaging to effect acceleration. We propose DISCO (DIfferential Subsampling with Cartesian Ordering), a flexible k-space segmentation scheme that minimizes sensitivity to eddy currents and motion for dynamic imaging while dispersing artifacts and residual ghosting and demonstrate its use in first pass contrast enhanced liver imaging. Motion Correction Hall B Tuesday 13:30-15:30 3045. Advancements in Contact-Free Respiration Monitoring Using RF Pick-Up Coils Ingmar Graesslin1, Giel Mens2, Alexander Guillaume1, Henry Stahl3, Peter Koken1, Peter Vernickel1, Paul Harvey2, Jouke Smink2, Kay Nehrke1, Peter Boernert1 1Philips Research Europe, Hamburg, Germany; 2Philips Healthcare, Best, Netherlands; 3FH Westküste, Heide, Germany Advanced methods of motion detection and motion artifact reduction help to improve diagnostic image quality. The use of conventional navigators requires additional planning and adversely influences the steady state, which can result in image artifacts. A new approach was presented that uses the detection of changes of RF coil loading induced by the respiratory motion of the patient. This paper describes the application of a real-time self-navigated respiration monitoring approach using dedicated RF monitoring pulses instead the RF excitations of the imaging sequence. RF amplifier drift is analyzed, and a compensation scheme is proposed to overcome this problem. 3046. 3D TOF Angiography Using Real Time Optical Motion Correction with a Geometric Encoded Marker Daniel Kopeinigg1,2, Murat Aksoy1, Christoph Forman3, Roland Bammer1 1Department of Radiology, Stanford University, Palo Alto, CA, United States; 2Institute of Medical Engineering, University of Technology Graz, Graz, Austria; 3Pattern Recognition Lab, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany Correction of motion artifacts is an ongoing and very important task in MRI. This motion, most often introduced by patients that suffer from a medical condition, which makes it difficult to remain motionless during MRI acquisitions, can significantly corrupt the resulting images and their diagnostic value. In this study we show first in-vivo results of our prospective optical motion correction system applied to three-dimensional time of flight (3D TOF) angiography. Results show that compared to the non-motion corrected case the real-time motion correction is able to dramatically improve image quality of 3D TOF angiograms. 3047. Motion Characterisation Using FID Navigators and Spatial Pattern of MRI Coil Arrays Tobias Kober1,2, José P. Marques1,3, Rolf Gruetter1,4, Gunnar Krueger2 1Laboratory for functional and metabolic imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; 2Advanced Clinical Imaging Technology, Siemens Suisse SA - CIBM, Lausanne, Switzerland; 3Department of Radiology, University of Lausanne, Lausanne, Switzerland; 4Departments of Radiology, Universities of Lausanne and Geneva, Switzerland In this work we investigate the potential to characterise rigid-body head motion by monitoring free induction decay (FID) changes over time in coil arrays. The technique makes use of the fact that FID signals detected by local coil elements change as a function of object distance. Assuming a sufficient coverage of the scanned object with local coil elements, the inverse problem of back-calculation of the rigid motion parameters may be solvable. In this investigation, a framework to derive these motion parameters is developed and first results are shown from phantom and human scans using a 32-channel head coil array. 3048. Iterative Motion Compensated Reconstruction Tim Nielsen1, Peter Boernert1 1Philips Research Europe, Hamburg, Germany Motion during data acquisition can seriously degrade image quality. Motion compensated reconstruction can restore image quality if the motion is measured with suitable navigator signals. We present a new scheme for motion compensated reconstruction which can be applied to segmented Cartesian acquisitions (e.g. TSE, TFE). It can be combined with parallel imaging and is fast because it works mainly in the spatial domain avoiding many Fourier-transforms between k-space and image space. The motion is detected and quantified by adding an orbital navigator echo in front of the imaging echoes. Mei-Lan Chu1, Jia-Shuo Hsu1, Hsiao-Wen Chung1 1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan Estimation of the baseline is essential in compressed-sensing-based acceleration methods for MRI acquisition, as an accurate baseline estimation helps sparsifying the residues effectively. Recent literatures suggest improved baseline estimation using adaptive regularization or motion estimation (ME) and compensation (MC). While the suitability of these methods on other dynamic images with fast-varying contrast and morphology such as dynamic contrast-enhanced (DCE) lung imaging have not been investigated. Therefore, the purpose of this study is to explore the baseline estimation performance of the block-matching and the phase-correlation ME/MC on both cine cardiac and DCE lung imaging, in comparison with the conventional approach. 3050. Simple Self-Gating for Compensation of Respiratory Motion Using a Spiral K-Space Trajectory Rafael Luis O'Halloran1, Murat Aksoy1, Tobias Kober2, Roland Bammer1 1Department of Radiology, Stanford University, Stanford, CA, United States; 2Laboratory for functional and metabolic imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland A simple method of respiratory monitoring using the phase of the DC term of k-space collected with a spiral k-space trajectory is presented and compared with the measurement from the respiratory bellows. The method presented is shown to be in excellent agreement with the measurement from the respiratory bellows and reveal even cardiac pulsatility. In this work the method is used to gate a spiral-trajectory scan of the liver. The image reconstructed with the DC phase used for gating was qualitatively similar to the one reconstructed using conventional gating. Since the image data is used for gating no additional navigators must be acquired. 3051. Methodology for Robust Motion Correction of Complex-Valued MRI Time Series Andrew Hahn1, Daniel Rowe2 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 2Mathematics, Statistics, and Computer Science, Marquette University, Milwaukee, WI In functional MRI, subject motion during the acquisition of an image series can confound results and is generally corrected for using a variety of methods. Because statistical models for performing complex-valued fMRI analysis are available which can provide some benefits beyond the standard magnitude-only technique, investigation of a signal resulting from direct neuronal current involves complex-valued analysis, and recent reports have indicated potentially valuable functionally related phase signal, performing motion correction on complex-valued time series is of interest. This work identifies the problems facing motion correction of complex-valued images and proposes a solution for properly applying the correction. 3052. Compensation for Nonrigid Motion Using B-Spline Image Registration in Simultaneous MR-PET Se Young Chun1, Sanghee Cho1, Tim G. Reese2, Bastien Guerin1, Xuping Zhu1, Jinsong Ouyang1, Ciprian Catana2, Georges El Fakhri1 1Division of Nuclear Medicine & Molecular Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States; 2Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States This abstract reports preliminary results of motion corrected MR-PET reconstruction based on B-spline nonrigid image registration and compares it with HARP based motion compensation. With a breathing phantom, we collected MR and PET data simultaneously using BrainPET prototype PET scanner operating in the bore of a 3T TIM Trio scanner. Then we estimate the motion of a phantom using HARP and proposed B-spline based image registration with a novel invertibility penalty. These estimated motions were used in motion compensated iterative PET reconstruction. This preliminary result shows significant improvement of PET images for large motions. 3053. Respiratory Motion Correction of PET Using Simultaneously Acquired Tagged MRI Timothy Gordon Reese1, Bastien Guérin2, Sanghee Cho2, Se Young Chun2, Jinsong Ouyang2, Xuping Zhu2, Ciprian Catana3, Georges El Fakhri2 1Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital , Boston , MA, United States; 2Division of Nuclear Medicine & Molecular Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States; 3Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States As the spatial resolution of PET scanners improves, the deleterious effects of patient motion become an ever increasing limitation in PET studies. We present our first results with incorporating clinically relevant motion information derived from MR into the PET reconstruction process. We describe our current methods for tracking non-rigid periodic motion over the entire FOV of the MR-PET scanner, during the PET acquisition. All PET coincidences were reconstructed in a single frame while correcting the data for motion using MRI, demonstrating feasibility on an actual MR-PET system and a significant improvement in PET image quality. 3054. DCE-MRI Non-Rigid Kidney Registration Michael Hofer1, Steven Keeling2, Gernot Reishofer3, Michael Riccabona4, Manuela Aschauer3, Rudolf Stollberger1 1Institute of Medical Engineering, Graz University of Technology, Graz, Austria; 2Institute for Mathematics and Scientific Computing, University of Graz, Graz, Austria; 3Department of Radiology, Medical University of Graz, Graz, Austria; 4Department of Pediatric Radiology, Medical University of Graz, Graz, Austria Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is a very promising method for noninvasive assessment of renal function. To remove the influence of motion artifacts like breathing, a novel registration approach is proposed which derives a template image series with the underlying signal time course. This results in an independency from signal changes due to contrast media uptake. The original dynamic time series (source images) is then registered by elastic registration to this virtual template. The algorithm successfully reduces motion artifacts. Comparisons between pre and post registration underlines the importance of image registration in DCE-MRI examinations. Kaining Shi1,2, Russell Low3, Shanglian Bao1, Jingfei Ma2 1Beijing City Key Lab of Medical Physics and Engineering, Beijing University, Beijing, China; 2Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX, United States; 3Sharp and Children's MRI Center, San Diego, CA, United States The triple echo readout in the FTED sequence presents a challenge to achieve flow-compensation along the frequency-encode direction. In this work, two flow-compensation methods were proposed. In the first method, gradient moments are nulled at every RF locations so that the CPMG condition is always maintained. In the second method, the spin echo component of the signal is nulled at the 1st and 3rd echo locations and the stimulated component is minimized at different echo locations. The effectiveness of both methods in reducing the flow-induced artifacts was examined with a numerical calculation and demonstrated in a phantom testing. 3056. On the Optimization of Parallel Imaging for Ghost Reduction: A Blood Flow Example Feng Huang1, Wei Lin1, Yu Li1, Arne Reykowski1 1Invivo Corporation, Gainesville, FL, United States A parallel imaging based technique, COnvolution and Combination OperAtion (COCOA), has been proposed recently to efficiently remove ghost artifacts due to non-rigid motion. COCOA has two steps: a convolution step for a synthetic k-space with redistributed error, and a combination step for the final reconstructed k-space with reduced error. In this work, by using blood flow artifact as an example, the optimization schemes for these two steps are introduced to improve the ability for ghost suppression. Christian Buerger1, Andrew Peter King1, Tobias Schaeffter1, Claudia Prieto1 1Division of Imaging Sciences, King's College London, London, United Kingdom A method for reconstructing multiple high-resolution respiratory phases from free-breathing 3D-MRI is presented. The proposed method combines an undersampled self-gating acquisition with a non-rigid image registration scheme. This approach uses all the acquired data to reconstruct a single high spatial resolution (HSR) phase at the most visited respiratory position and multiple respiratory resolved (RR) images at the remaining phases followed by an improving of image quality for all RR images (suffering from remained aliasing artifacts) using a registration procedure. This aligns the features of HSR with the remaining RR phases, leading to a sequence of time-resolved high resolution respiratory phases. 3058. MOtion Correction Using Coil Arrays (MOCCA) Peng Hu1, Mehdi H. Moghari1, Beth Goddu1, Lois A. Goepfert1, Thomas H. Hauser1, Warren J. Manning1, Reza Nezafat1 1Beth Israel Deaconess Medical Center, Boston, MA, United States We present a novel motion correction method using coil arrays (MOCCA). In MOCCA, the elements of a coil array are used as individual motion sensors which detect the motion-induced signal variations that are modulated by coil sensitivity maps. The inclusion of multiple coils by stacking multi-coil data into a column vector increased the accuracy of motion detection compared to existing methods based on projections. We evaluate the accuracy of MOCCA in a phantom and demonstrated the application of MOCCA on healthy volunteers for bulk motion correction in brain imaging and for respiratory and cardiac self-gating in cardiac cine imaging. 3059. Handling Motion in Sparse Reconstruction with Whiskers Jason K. Mendes1, Dennis L. Parker1 1UCAIR, University of Utah, Salt Lake CIty, UT, United States In general, the minimum number of K-Space samples required to produce good results in sparse reconstruction is approximately four times the number of sparse coefficients. Patient motion that is neither periodic nor smooth will reduce sparsity in the temporal direction and degrade the success of the sparse reconstruction. It is therefore beneficial to detect and correct as much patient motion as possible to maximize temporal sparsity and thus reduce the total number of K-Space samples required. This is accomplished using a hybrid Radial-Cartesian sampling technique called. This sequence has an inherent ability to correct bulk patient motion and is well suited to non-linear sparse reconstruction. 3060. Towards Lissajous Navigator-Based Motion Correction for MR-PET Marcus G. Ullisch1,2, Tony Stöcker1, Kaveh Vahedipour1, Eberhard D. Pracht1, Lutz Tellmann1, Hans Herzog1, Nadim Jon Shah1,3 1Institute of Neuroscience and Medicine 4, Forschungszentrum Jülich GmbH, Jülich, Germany; 2Department for Psychiatry and Psychotherapy, RWTH Aachen University, Aachen, Germany; 3Faculty of Medicine, Department of Neurology, RWTH Aachen University, Aachen, Germany With the combination of Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) into a single combined system, a novel imaging modality has become available. Previous approaches to patient motion tracking for PET data correction are difficult to use in the combined MR-PET environment. Thus, alternative methods for motion tracking have to be developed. Here, a novel approach for MR-PET motion correction utilising the Lissajous navigator is presented. 3061. 4D MAP Image Reconstruction of MRI Data Jacob Hinkle1, Ganesh Adluru2, Edward DiBella2, Sarang Joshi1 1Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, United States; 2Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, UT, United States Conventional MRI reconstruction techniques are susceptible to artifacts when imaging moving organs. In this paper, a reconstruction algorithm is developed that accommodates motion instead of altering the scanning protocol. The maximum a posteriori (MAP) algorithm uses the raw time-stamped data to reconstruct the images and estimate deformations in anatomy simultaneously. The algorithm eliminates artifacts by avoiding gating processes and increases signal-to-noise ratio (SNR) by using all of the collected data. The algorithm is tested in a simulated torso phantom and is shown to increase image quality by dramatically reducing motion artifacts. 3062. Impact of Mechanical Vibration During DWI on Diffusion Parameter Estimation in Human Kidneys Peter Vermathen1, Tobias Binser1, Chris Boesch1 1Dept. Clinical Research, University Bern, Bern, Switzerland DWI leads to patient table vibration that may affect image quality, as has been demonstrated previously in phantoms and brain. We therefore investigated the impact of mechanical vibration during abdominal DWI on diffusion parameter estimation. Diffusion scans were performed on three subjects that were once in direct contact with the MR-system, thus experiencing vibration, and once without contact to the MR-System. The results demonstrate that the impact of vibration on diffusion parameter estimation, including micro-perfusion estimation, and also on the image intensity is only small. This holds true for standard measurement parameters. 3063. On the Application of TGRAPPA in Functional MRI Hu Cheng1 1Indiana University, Bloomington, IN, United States GRAPPA has been widely used in fMRI recently to improve spatial resolution. A drawback of GRAPPA for fMRI is that head motion in the reference scans can result in significant artifact for all the images in a run and higher temporal noise level. This problem can be solved by TGRAPPA using time interleaved sampling scheme. Separate reconstruction is needed for the interleaved k-space to minimize signal variation from volume to volume caused by phase errors. Although TGRAPPA has less statistical power than GRAPPA, the ability of retrospective motion correction makes it appealing in some application. 3064. Necessity of Sensitivity Profile Correction in Retrospective Motion Correction Chaiya Luengviriya1,2, Jian Yun1, Kuan Lee3, Julian Maclaren3, Oliver Speck1 1Department of Biomedical Magnetic Resonance, Otto-von-Guericke University, Magdeburg, Germany; 2Department of Physics, Kasetsart University, Bangkok, Thailand; 3Department of Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany Image artifacts induced by subject motion during multi-channel MRI were simulated for different sensitivity map profiles and different amounts of abrupt random motion. More localized maps resulted in stronger artifacts in the images. Two procedures for retrospective motion correction, k-space signal correction and sensitivity map correction were applied during an iterative non-Cartesian SENSE reconstruction. The signal correction evidently reduced the artifacts. The sensitivity map correction further improved image quality for strong motion and highly localized maps, at the cost of a longer computation time. For small motion and less localized maps, sensitivity map correction can be avoided since no improvement was visible. 3065. Dynamic Imaging Motion Artifact Reduction Using Adaptive K-Space Polynomial Interpolation Travis B. Smith1, Krishna S. Nayak1 1Electrical Engineering, University of Southern California, Los Angeles, CA, United States Any object movement during or between MRI acquisition readouts leads to data inconsistency artifacts in the images. The manifestation of these artifacts depends on the k-space sampling trajectory. For example, in echo-planar imaging they appear as ghosting artifacts, and in spiral imaging they manifest as swirling artifacts. Dynamic imaging, which attempts to capture body or physiological motion through continuous acquisitions, is vulnerable to these artifacts. In this work, we present an adaptive polynomial interpolation algorithm to reduce these artifacts without introducing significant motion blurring. In-vivo results are presented to compare the algorithm with other motion artifact reduction techniques. 3066. Magnitude-Weighted Phase Based Edge Detection for Navigator Gated Imaging Kenichi Kanda1, Yuji Iwadate2, Yoshikazu Ikezaki1 1MR Engineering, GE Healthcare Japan, Hino, Tokyo, Japan; 2MR Applied Science Laboratory, GE Healthcare Japan, Hino, Tokyo In navigator echo technique, accurate position detection of the diaphragm is essential. The edge detection analysis based on the phase profile of navigator enables the navigator gated imaging even with the saturation effect. However, the phase profile is sometimes unstable in the lung, and wrong position can be detected accordingly. We present a hybrid algorithm utilizing both magnitude and phase information to detect the diaphragm position. Our results show that the edge detection based on the magnitude-weighted phase data can detect the diaphragm position accurately even when the data have a fuzzy magnitude edge or noisy phase in the lung. 3067. Irretrievable Signal Loss in Partial-Fourier Acquired Diffusion-Weighted Images Marcel Peter Zwiers1, Eelke Visser2, David Gordon Norris2, Nico Papinutto3, Benedikt Andreas Poser2 1Donders Institute for Brain, Cognition and Behaviour, Nijmegen, -, Netherlands; 2Donders Institute for Brain, Cognition and Behaviour, Nijmegen, Netherlands; 3Center for Mind-Brain Sciences, Trento, Italy Diffusion weighted (DW) partial-Fourier (PF) imaging is highly sensitive to cardiac activity induced signal voids that depend critically on the image reconstruction method. The current explanation is that these artefacts result from incorrect phase estimation. We found that artefacts remained present in the PF acquired images, even when using zero-padding reconstruction or true (ideal) phase information. Cardiac pulsations induce phase gradients that can shift the local low-frequency information into the unacquired part of k-space. The associated signal voids are therefore irretrievable by any PF reconstruction method. Thus, PF DW imaging should generally be avoided or used solely with cardiac gating. 3068. Robust and Fast Evaluation of Orbital Navigator Data for Rigid Body Motion Estimation Tim Nielsen1, Peter Boernert1 1Philips Research Europe, Hamburg, Germany To overcome image artifacts induced by motion the use of navigator signals has been proposed, combined with either real-time correction of the data acquisition or motion compensated reconstruction. The quality of the correction depends critically on the estimated motion derived from the navigator signal. We present a fast, robust and precise algorithm to evaluate data from an orbital navigator trajectory and its application to motion compensated reconstruction. 3069. Direct and Independent Estimation of B0 Components Based on Raw EPI Data Frederik Testud1, Iulius Dragonu1, Jürgen Hennig1, Maxim Zaitsev1 1Medical Physics, Department of Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany GE EPI is a widely used imaging technique, but is very sensitive to B0 field inhomogeneities. To correct for temporal changes of B0, real-time measuring methods are necessary, such as estimating gradient maps of B0 from raw EPI data. Here a filter scheme is presented to calculate local B0 gradients. The local gradient in the readout direction is estimated independently from the gradient in the phase encoding direction by finding the contour lines of the gradients. This method is compared with previously introduced raw data based techniques and shown to perform better or equally well. 3070. Rapid Retrospective Non-Rigid Motion Correction for Free-Breathing MRI Yoshihiro Tomoda1, Yuji Iwadate2, Tetsuji Tsukamoto2, Yoshikazu Ikezaki1 1MR Engineering, GE Healthcare Japan, Hino, Tokyo, Japan; 2MR Applied Science Laboratory, GE Healthcare Japan, Hino, Tokyo, Japan We proposed a new framework that enables not only non-rigid motion correction with 100% acceptance rate but also rapid reconstruction. As the first investigation, we implemented the 1D non-rigid motion correction, called 1D MMFK, and confirmed the effectiveness with the simple linear expansion model by numerical simulation and volunteer scan. 3071. Correction of Motion Artifacts Using a Genetic Algorithm Stephan Witoszynskyj1, Alexander Rauscher2 1Department of Radiology , Medical University of Vienna, Vienna, Austria; 2UBC MRI Research Centre, University of British Columbia, Vancouver, BC, Canada We present a genetic algorithm for correction of motion artifacts in MRI. Two types of genetic algorithms were investigated: the first used only "non-sexual" multiplication and the second allowed "cross-over" between solutions. The algorithm corrects for translations by estimating correction factors for each k-space line. Four different image metrics were studied: entropy, normalized-gradient-squared (NGS), signal in the background and local coherence in the background. The best results were obtained by using the simple algorithm and NGS and entropy as metric. Since genetic algorithms are inherently parallelizable our approach could benefit greatly from being implemented on computer clusters and GPUs. 3072. Less Can Be More: Reduction of Motion Artifacts by Ignoring Parts of the Acquired Dataset Tim Nielsen1, Jinnan Wang2,3, Peter Boernert1 1Philips Research Europe, Hamburg, Germany; 2Philips Research North America, Briarcliff Manor, NY, United States; 3University of Washington, Seattle, WA, United States High resolution MR imaging of the carotids is an interesting technique for plaque characterization but image quality can be compromised by motion artifacts. Effects of breathing and pulsation can be reduced by gated acquisition. Coping with non-periodic motion (e.g. swallowing) is still often challenging in clinical practice and is considered as a major factor that contributes to the overall 20% failure rate in clinical scans. We present a method to reduce the effects of sudden, non-periodic motion by exploiting data redundancy which is usually present in parallel imaging with multiple receive coils. The method can be applied retrospectively without any navigator information. 3073. Fast Phase Based Registration for Robust Quantitative MRI Anders Eklund1,2, Marcel Warntjes, 2,3, Mats Andersson1,2, Hans Knutsson1,2 1Division of Medical Informatics, Department of Biomedical Engineering, Linköping University, Sweden; 2Center for Medical Image Science And Visualization (CMIV), Linköping University, Sweden; 3Division of Clinical Physiology, Department of Medicine and Health, Linköping University, Sweden Quantitative magnetic resonance imaging has the major advantage that it handles absolute measurements of physical parameters. Quantitative MRI can for example be used to estimate the amount of different tissue types in the brain, but other applications are possible. When quantitative MRI is performed, a number of volumes are collected from the MR scanner. In order for the tissue quantification to work properly, the volumes have to be perfectly aligned. The problem with the volumes is that they differ significantly in intensity. We present a method for fast registration of such volumes and prove that it is more robust than the statistical parametric mapping (SPM) software. 3074. Navigator-Based Elliptical K-Space Reordering for Aortic 4D-Flow Imaging Ashley Gould Anderson III1, Sebastian Gruhlke2, Oliver Wieben1,3, Michael Markl2,4 1Medical Physics, University of Wisconsin, Madison, WI, United States; 2Medical Physics, University Hospital Freiburg, Freiburg, Germany; 3Radiology, University of Wisconsin, Madison, WI, United States; 4Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany Respiratory motion causes significant artifacts during 4D-Flow imaging in the torso due to long scan time requirements. Respiratory gating based on navigator signals or external measurements with bellows have been shown to reduce phase-related motion artifacts in long two- and three-dimensional free breathing acquisitions. Moreover, real-time adaptive k-space reordering, i.e. phase encoding based on the current position in the respiration cycle, can considerably improve navigator efficiency and thus reduce overall scan time. This work builds on proven respiratory gating and compensation methods by extending them to include reordering in the 3D slice-select direction in addition to the phase-encoding direction. 3075. Background Phase Correction Using K-Space Filters in Phase Contrast Velocity Encoded MRI Martin Uppman1, Michael Markl2, Bruce S. Spottiswoode3,4 1Lund Institute of Technology, Lund, Sweden; 2Diagnostic Radiology, Medical Physics, Albert-Ludwigs Universität, Freiburg, Germany; 3MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, South Africa; 4Department of Radiology, Stellenbosch University, South Africa This work evaluates k-space high-pass filtering as a post-processing background phase correction technique for 2D phase contrast velocity encoded MRI. Results are compared to an established technique which involves estimating the phase variation in stationary tissue and subtracting a fitted polynomial surface. Phantom and in-vivo studies show that k-space filtering with a large kernel performs equally as well as a high order polynomial surface subtraction. 3076. Intrinsic Detection of Corrupted Data Jason K. Mendes1, Dennis L. Parker1 1UCAIR, University of Utah, Salt Lake CIty, UT, United States Correlations between adjacent K-Space lines can be used to detect non-rigid body motion or motion that occurs out of plane. The cross correlation between two adjacent sets of equally spaced K-Space lines is a set of equally spaced delta functions convolved with an error function. The error function is a result of correlation errors between adjacent sets of lines. These errors are present even when there is no motion of any kind, however, as the amount of data corruption increases the error function broadens. As a result, a measure of the relative sharpness of the error function provides a measure of data corruption. 3077. SPI Motion Correction Using In-Plane Estimates Ryan Keith Robison1, Kenneth Otho Johnson1, James Grant Pipe1 1Keller Center for Imaging Innovation, Barrow Neurological Institute, Phoenix, AZ, United States Spiral Projection Imaging (SPI) allows for intrinsic estimation of rigid-body patient motion through the comparison of data between spiral planes that correspond to different time points but similar k-space locations. The in-plane estimation scheme produces 2D estimates of motion for each spiral plane. Full 3D motion estimates can be obtained for each plane by combining the 2D estimates of spatially orthogonal, sequential triplets of spiral planes. In-vivo images and quantitative estimation results are presented for simulated and in-vivo motion affected data. Mei-Lan Chu1, Jia-Shuo Hsu1, Hsiao-Wen Chung1 1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan Motion estimation (ME) and motion compensation (MC) are successfully exploited by dynamic MRI as baseline estimation for enhancing reconstruction. However, ME and MC have not been exploited as a standalone approach for direct dynamic MRI reconstruction, since the absence of full-resolution frames. A robust reconstruction technique was proposed in this work to address this issue, based solely on phase-correlation ME and MC methods without incorporating extra reconstruction routine. Cine cardiac images are tested with the proposed method, and the results indicate that the proposed method can achieve improved temporal resolution even from substantially down-sampled k-space data. Image Correction: Gradients & Frequency Hall B Wednesday 13:30-15:30 3079. Compressive Slice Encoding for Metal Artifact Correction Wenmiao Lu1, Kim Butts Pauly2, Garry Evan Gold2, John Mark Pauly3, Brian Andrew Hargreaves2 1Electrical & Electronic Engr., Nanyang Tech. University, Singapore, Singapore; 2Radiology, Stanford University, Stanford, CA, United States; 3Electrical Engr., Stanford University, Stanford, CA, United States Metal artifacts in MRI can be completely corrected by Slice Encoding for Metal Artifact Correction (SEMAC), which nonetheless incurs prolonged scan times due to the additional phase encoding along slice-select direction. Here we incorporate SEMAC with compressed sensing to vastly reduce the number of phase encoding steps required to resolve metal artifacts. The new technique, referred to as Compressive SEMAC, can greatly reduce scan times, while producing high-quality distortion correction and SNR comparable to SEMAC with full sampling. Wenmiao Lu1, Kim Butts Pauly2, Garry Evan Gold2, John Mark Pauly3, Brian Andrew Hargreaves2 1Electrical & Electronic Engr., Nanyang Tech. University, Singapore, Singapore; 2Radiology, Stanford University, Stanford, CA, United States; 3Electrical Engr., Stanford University, Stanford, CA, United States To obtain distortion-free MR images near metallic implants, SEMAC (slice encoding for metal artifact correction) resolves metal artifacts with additional z-phase encoding, and corrects metal artifacts by combining multiple SEMAC-encoded slices. However, many of the resolved voxels contain only noise rather than signals, which degrades signal-to-noise ratio (SNR) in the corrected images. Here the SEMAC reconstruction is modified to perform denoising using singular value decomposition, which exploits the redundancy in the SEMAC-encoded data received from multiple coils. We demonstrate the efficacy of the proposed technique in several important imaging scenarios where SEMAC-corrected images are liable to relatively low SNR. 3081. Imaging Near Metals with Phase Cycled SSFP Michael Nicholas Hoff1, Jordin D. Green2, Qing-San Xiang1,3 1Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada; 2Siemens Healthcare, Calgary, Alberta, Canada; 3Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada A fast bSSFP technique is devised for removing imaging artifacts near metals. 3D phase cycled TrueFISP provides comprehensive artifact reduction using powerful gradients, two dimensions of phase encoding, short TR, and thorough refocusing of magnetization. Problematic banding artifacts are eliminated using a technique which formulates expressions for each voxels modulated magnetization, and then analytically solves the system with a simple Cross-Solution (XS) to obtain the demodulated magnetization. Application to a phantom consisting of a hip prosthesis within a Lego structure confirms that 3D imaging with XS-SSFP is simple, efficient, and robust in artifact reduction. 3082. B1 Effects When Imaging Near Metal Implants at 3T Kevin M. Koch1, Kevin F. King1, Graeme C. McKinnon1 1Applied Science Laboratory, GE Healthcare, Waukesha, WI, United States Recently developed techniques have enabled low susceptibility-artifact imaging near metal implants using conventional spin-echo acquisition strategies. Previous demonstrations of these techniques have been presented at 1.5T. While the susceptibility artifact mitigation of these techniques remains sufficient at 3T, here we address the effects of reduced B1 wavelength applied at 3T. These effects introduce increased B1 artifacts near metal implants, particularly those with long axes oriented collinear with B0. Finite element simulations and phantom images are presented to demonstrate and discuss these effects. 3083. Adaptive Slice Encoding for Metal Artifact Correction Brian A. Hargreaves1, Garry E. Gold1, John M. Pauly2, Kim Butts Pauly1 1Radiology, Stanford University, Stanford, CA, United States; 2Electrical Engineering, Stanford University, Stanford, CA, United States Slice encoding for metal artifact correction (SEMAC) excites 2D slices, then uses a 3D encoding to resolve the distortion of slices due to large metal-induced susceptibility shifts. The addition of a simple, fast spectral prescan easily estimates the extent of this distortion, allowing the slab width and encoded field-of-view to be adapted to the subject. This, allows the total number of excited slices to be greatly reduced without diminishing final image quality, thus offering a substantial reduction in SEMAC scan time. 3084. Fat-Suppressed and Distortion-Corrected MRI Near Metallic Implants Brian A. Hargreaves1, Wenmiao Lu2, Kim Butts Pauly1, John M. Pauly3, Garry E. Gold1 1Radiology, Stanford University, Stanford, CA, United States; 2Electrical & Electronic Engineering, Nanyang Tech University, Singapore, Singapore; 3Electrical Engineering, Stanford University, Stanford, CA, United States Fluid-sensitive volumetric imaging of patients with metallic implants is potentially an important diagnostic tool to assess for infection, implant loosening, or other complications. Recent MR techniques use spin echoes combined with additional encoding to substantially reduce distortion and signal loss artifacts. Here we demonstrate the use of these sequences with short TI inversion recovery (STIR) to provide reliable fat suppression near metallic implants, which is particularly important in assessment of many disorders. 3085. Spiral Chemical Shift Imaging in the Presence of Metal Artifacts Atsushi M. Takahashi1 1Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States MRI in the presense of metal in the body is complicated by B0 field perturbations and by the shortening of the T2* relaxation times. With a multi-interleave, short readout, spiral k-space trajectory, chemical shift imaging method, we can image in the presence of metal. Here we describe a method which can be used in-vitro to visualize the field maps surrounding metal implants. A Koenig1,2, Frank Reintke2, Gerrit Schönwald, 2,3, Gregor Schaefers2 1University of applied Science Gelsenkirchen, Gelsenkirchen, NRW, Germany; 2MR Safety Testing Laboratory, MR:comp GmbH, Gelsenkirchen, Germany; 3University Witten/Herdecke The ASTM-Standard F2119-07 is used to evaluate artifacts of implants. According to the test method a phantom with CuSO4 is used. By replacing the solution by mineral oil it is desired to avoid standing waves in images. We tested both fluids in two sequences (SE/GRE) with 2 test devices, a Nitinol stent and an acryl reference tube. We compared a visual, a statistically and a manual analysis. We noticed non-significant results with one exception. Under certain conditions the standard CuSO4 can be exchanged with mineral oil allowing better and precise artifact analysis at higher field strengths ”Ż 3 T. 3087. Comparison of Fat Suppression Methods for Functional and Diffusion Studies Using SE EPI at 7T Dimo Ivanov1, Markus Streicher1, Andreas Schäfer1, Robert Turner1 1Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany The increased SNR of ultra-high-field MR scanners allows high resolution functional and diffusion studies to be performed. Because chemical-shift artifact suppression is essential for SE EPI images, we evaluated the performance of different fat suppression techniques. Conventional methods using additional radiofrequency (RF) and gradient pulses provide suboptimal results owing to increased B0 and B1 inhomogeneity at higher fields. They also increase RF power deposition. A recently developed method using different slice-select gradient strengths during the excitation and refocussing pulses was demonstrated to be most robust, and delivered best chemical shift selection.
3088. Dynamic Frequency Drift Correction for Binomial Water Excitation Dehe Weng1,2, Feng Xiu3, Xiaodong Zhou1,4, Qiang He1,4 1Siemens Mindit Magnetic Resonance Ltd, Shenzhen, Guangdong, China; 2Beijing MRI Center for Brain Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; 3Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen, Guangdong, China; 4Life Science and Technology School, Tongji University, Shanghai, China Binomial water excitation is useful in low field MR system (<0.5T) for fat suppression, but it is vulnerable to main magnetic field instability. Dynamic magnetic field measurement is introduced in this method. The initial phase of the RF pulses except the first RF pulse in the binomial RF train is modified afterward in order to improve the performance of fat suppression. Result shows that lipid signal was suppressed well while water signal is enhanced in volunteer images. 3089. Reconstruction and Frequency Mapping with Phase-Cycled BSSFP Francesco Santini1, Klaus Scheffler1 1Radiological Physics, University of Basel Hospital, Basel, Switzerland Balanced SSFP images are sensitive to off-resonance effects, showing signal voids in correspondence to particular frequency values. Application of phase cycling to the RF pulses changes the frequency values at which the signal voids appear, therefore a single artifact-free image can be obtained by multiple acquisition. In this work, the data acquired from four phase cycles are fitted to the classical Freeman-Hill formula describing the signal behavior of bSSFP, and an artifact-free image together with a frequency map is obtained. 3090. Pre-Processing Phase: A Quantitative Analysis of Established Methods in SWI Ferdinand Schweser1, Alexia Rodrķguez-Ruano2,3, Andreas Deistung3, Berengar Wendel Lehr3, Manuel Desco2, Jürgen Rainer Reichenbach3 1Medical Physics Group, Department of Diagnostic and Interventional Radiology , Jena University Hospital, Jena, Germany; 2Medicina y Cirugķa Experimental, Hospital General Universitario Gregorio Marańón, Madrid, Spain; 3Medical Physics Group, Department of Diagnostic and Interventional Radiology, Jena University Hospital, Jena, Germany Well-established methods for estimation of background field contributions were quantitatively analyzed based on a realistic numerical whole-body model. The results indicate that interpretability of phase data strongly depends on chosen filter-type, filter-parameter, and region of interest. 3091. Discontinuities in the Distortion Field: Correction of the Fat-Shift Artifact Lesley N. Baldwin1, K Wachowicz2, B Gino Fallone, 12 1Department of Physics, University of Alberta, Edmonton, Alberta, Canada; 2Department of Oncology, University of Alberta, Edmonton, Alberta, Canada MR images are known to suffer from geometric distortion from a variety of sources. Boundaries between fat- and water-based tissues lead to discontinuities in the distortion field and result in hyper- and hypo-intense regions which cannot be corrected using standard distortion correction procedures. We propose a number of pre-processing steps which separate the image into fat and water components and shift the fat portion of the image prior to distortion correction. The technique was successfully demonstrated on phantom images and work is underway to evolve and apply the technique to more complex in-vivo images. Andrew Hahn1, Andrew Nencka1, Daniel Rowe2 1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States; 2Mathematics, Statistics, and Computer Science, Marquette University, Milwaukee, WI Methods of correcting the effects resulting from magnetic field inhomogeneities and off-resonance that have proven to be most effective in recovering homogenous image intensity, recovering signal dropout and providing optimal image unwarping often involve inverting a matrix kernel constructed with prior knowledge of the magnetic field. Field maps estimated using echo-planar images are very convenient to acquire, but are not compatible with the mentioned group of algorithms due to their warped space coordinates. A straightforward method is presented providing a connection between echo-planar based maps and optimal correction schemes leveraging both the convenience and performance of the combination. 3093. Correcting Susceptibility Artifacts to Accurately Target Deep Brain Structures Frank Q. Ye1, Charles C. Zhu1, Ning Liu2, Janita N. Turchi3, David A. Leopold1,3 1Neurophysiology Imaging Facility, National Institute of Mental Health, NIH, Bethesda, MD, United States; 2Laboratory of Brain and Cognition, National Institute of Mental Health, NIH; 3Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Bethesda, MD, United States High resolution, high contrast MRI scans can be used in neurophysiology research on nonhuman primates to plan invasive procedures that target deep brain structures. With procedures involving chronic, plastic head implants, susceptibility artifacts may severely distort the measurement of the projected entry trajectory. Geometric distortion correction based on field mapping is found both necessary and adequate to address this issue. Amanda Ng1,2, Zhaolin Chen2,3, Jingxin Zhang1, Gary F. Egan2,4, Leigh A. Johnston2,5 1Department of Electrical and Computer Systems Engineering, Monash University, Melbourne, Australia; 2Howard Florey Institute, Florey Neuroscience Institutes, Melbourne, Australia; 3Department of Electrical and Electronic Engineering, University of Melbourne, Melbourne, Australia; 4Centre for Neuroscience, University of Melbourne, Melbourne, Australia; 5Department of Electrical and Electronic Engineering & NICTA Victorian Research Laboratory, University of Melbourne, Melbourne, Australia Phase images in MRI are subject to inhomogeneities at the cortical surface due to susceptibility artefacts induced by air/tissue interfaces and insufficient filtering at foreground/background borders. We present a computationally efficient method of removing these inhomogeneities from phase unwrapped images using spatially dependent filters and omission of background voxels from the filtering calculations. The method is shown to successfully reveal structural detail in the cortical surface that is otherwise obscured in traditional filtering methods. 3095. Correction of RF Inhomogeneities in FLASH-Based T1 Mapping Using Unified Segmentation Nikolaus Weiskopf1, Antoine Lutti1, Gunther Helms2, John Ashburner1, Chloe Hutton1 1Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, University College London, London, United Kingdom; 2MR-Research in Neurology and Psychiatry, University Medical Center, Göttingen, Germany Quantitative T1 mapping based on variable flip angle acquisitions requires precise knowledge of the local flip angle and is therefore usually combined with RF transmit mapping methods. RF transmit mapping is not readily available and requires extra scan time. We propose a method to correct for RF inhomogeneities that does not require measured RF maps. The method uses the unified segmentation and bias correction approach implemented in SPM8 to simultaneously estimate and correct for the RF inhomogeneities from the T1 maps. The model-based approach is shown to reduce the bias in T1 maps by more than 50%. Jaco J.M. Zwanenburg1, Fredy Visser, 12, Vincent O. Boer1, Wybe JM van der Kemp1, Dennis W. Klomp1, Peter R. Luijten1 1Radiology, University Medical Center Utrecht, Utrecht, Netherlands; 2Philips Healthcare, Best, Netherlands It is shown that using BIR4 pulses for excitation and magnetization prepared inversion, can considerably improve the image homogeneity and contrast of FLAIR images at 7 Tesla, in areas with inhomogeneous B1+ fields. 3097. Distance Weighted B1 Uniformity Correction for Multiple Channel Image Reconstruction Fred J. Frigo1,2, Brian W. Thomsen1,2, Joshua V. Marso1,2, Jason M. Darby1,2, Stephen A. Verdi1,2, Chad A. Rowland1,2 1GE Healthcare, Waukesha, WI, United States; 2Marquette University, Milwaukee, WI, United States Conventional multiple channel image reconstruction benefits from increased signal-to-noise ratios however hyper-intensity near coil elements can lead to difficulties in the evaluation of images. We present a novel approach for multiple-channel magnetic resonance image reconstruction with pixel intensity corrections for B1 non-uniformity. Coil sensitivity maps are generated from the actual data acquired during a scan, so this is a self-referencing technique. The coil sensitivity maps for each channel are generated based on the Euclidean distance of pixels from each individual coil image to the coil elements. Noura Azzabou1,2, Paulo Loureiro de Sousa1,2, Pierre G. Carlier1,2 1NMR Laboratory, Institute of Myology, Paris, France; 2NMR Laboratory, CEA, I2BM, MIRCen, IdM, Paris, France We introduced here a new technique for non homogeneity correction that does not rely on prior knowledge about all the tissues in the image. To estimate the non uniformity field, we assumed that it can be modelled as a finite sum of cosine functions. To compute the parameters of the model, we minimised the variance of the image in the subcutaneous fat region under the constraint that the total variation of the field is minimum. The later constraint is the main contribution of this paper. Experimental results, on phantom, healthy subjects and pathological cases showed the efficiency of our model.
3099. Phase Correction in Bipolar Multi-Echo Water-Fat Separation for Off-Isocenter Imaging Hojin Kim1,2, Kyung Sung1, Misung Han1,2, Marcus Alley1, Wenmiao Lu3, Brian Andrew Hargreaves1 1Department of Radiology, Stanford University, Stanford, CA, United States; 2Department of Electrical Engineering, Stanford University, Stanford, CA, United States; 3School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore Bipolar multi-echo sequence benefits from reducing scan time as well as motion artifacts at the cost of several sources of phase discrepancy due to the polarity reversal in the readout gradient. To address phase correction in bipolar sequences, this work proposes the use of simple reference scan with baseline projections, which corrects linear and constant phase errors. Significantly, this proposed method is applied for off-isocenter imaging, so that accurate water-fat separation in bipolar sequence is capable at any scan location. Correcting Hardware Imperfections Hall B Thursday 13:30-15:30 Novena Rangwala1,2, Xiaohong Joe Zhou1,3 1Center for Magnetic Resonance Research, University of Illinois Medical Center, Chicago, IL, United States; 2Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, United States; 3Departments of Radiology, Neurosurgery and Bioengineering, University of Illinois Medical Center, Chicago, IL, United States A new technique for phase correction of individual blades for EPI-PROPELLER sequences is proposed. Constant, linear, and oblique phase corrections are performed by synthesizing the reference scans for arbitrary blade orientations, using only two reference scans acquired in orthogonal directions. This technique was found to decrease the Nyquist ghost by at least 75%, yielding images comparable to those obtained by using time-consuming, blade-specific reference scans. Atsushi M. Takahashi1 1Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States Gradient delays in MRI system are typically anisotropic and yield artifacts that are especially noticable in ramp sampled, center-out, radial k-space trajectories. We have developed a calibration procedure and a mathematical formulation for correcting artifacts from anisotropic gradient delays. 3102. Correcting for Gradient Imperfections in Ultra-Short Echo Time Imaging Jeremy F. Magland1, Hamidreza Saligheh-Rad1, Felix W. Wehrli1 1Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, PA, United States Imperfections in readout gradients can cause scanner-specific problems in ultra-short echo time (UTE) imaging sequences. In addition to slight gradient delays, the shape of the readout gradient waveform may not be trapezoidal. Here we describe a simple technique for mapping the k-space trajectory of the initial readout ramp in a UTE pulse sequence. The method uses data from a short calibration scan in which two dimensions of spatial encoding is applied prior to readout. After correcting for B0 inhomogeneity, the method provides a very accurate measurement of the k-space trajectory during the ramp, which can be used as input to a gridding-based reconstruction algorithm. Siawoosh Mohammadi1, Michael Deppe1, Harald E. Moller2 1Department of Neurology, University of Muenster, Muenster, NRW, Germany; 2Magnetic Resonance Unit, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Sachsen, Germany The strong lobes of the diffusion gradients cause different kinds of MR artifacts, like eddy-current (EC) and vibration effects. While EC effects could significantly be reduced using a twice-refocused spin-echo (TRSE) sequence for DTI acquisition, the vibration effects become more evident when the TRSE sequence is used. We showed that the vibration-induced motion leads to an affine scaling effect in x and y-direction that could be retrospectively corrected. While the y scaling is also subject to EC effects, the x scaling seems to correct solely vibration effects and might thus be usable for comparing vibration effects of different data sets. 3104. Rapid Concomitant Field Correction for 2D Spiral Imaging Ajit Devaraj1, Payal Bhavsar1, James G. Pipe1 1Keller Center for Imaging Innovation, Barrow Neurological Institute, Phoenix, AZ, United States Concomitant fields are a source of artifact for non-axial spiral images. The resulting artifacts are similar to Bo in-homogeneity blurring, hence challenging to account for. This work presents a rapid approach based on separable de-blur kernels. The efficacy of the proposed approach is demonstrated on both simulated and phantom sagittal images. Marco Reisert1, JĆ¼rgen Hennig1, Thimo Grotz1, Benjamin Zahneisen1 1Medical Physics, University Hospital Freiburg, Freiburg, Baden-Wuerttemberg, Germany Using a 3D rosette trajectory and iterative, regularized reconstruction a 643 volume can be acquired in less than 30ms. Single shot trajectories suffer from off-resonance effects because of their long readout times. Common off-resonance correction methods approximate the phase map by a time segmentation to correct for these effects but slow down the reconstruction. We therefore have developed an off-resonance correction, which uses an approximation in space rather than in time by deforming k-space interpolation kernels leading to a speed up of a factor of 10 at comparable reconstruction quality. 3106. MR Gradient Estimation Using a Linear Time Invariant Model Nii Okai Addy1, Holden H. Wu1,2, Dwight G. Nishimura1 1Electrical Engineering, Stanford University, Stanford, CA, United States; 2Cardiovascular Medicine, Stanford University, Stanford, CA, United States MR system imperfections limit the accuracy with which gradient waveforms of fast imaging trajectories such as spirals and 3D cones, are generated on the scanner. This mainly results in a delay of achieved k-space trajectories from the theoretical case. It is possible to measure the system delays for each axis and manually adjust the timing of the gradients to improve image reconstruction. However, a range of delay values can be observed on a single axis. This work models the gradient system with a linear time invariant model for accurate estimation of a range of gradient waveforms generated on the scanner. Roki Viidik1,2, Simon Bergstrand3, Tomas Karlsson3, Göran Starck2,4 1Department of Signals and Systems, Chalmers University of Technology, Göteborg, Sweden; 2Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Göteborg, Sweden; 3Institute of Neuroscience and Physiology, Sahlgrenska University Hospital, Göteborg, Sweden; 4Department for Radiation Physics, University of Gothenburg, Göteborg, Sweden Physiological registrations simultaneously with MR scanning usually require the removal of a huge gradient switching artefact from the weak physiological signal. We investigated a concept with pickup coils for simultaneous gradient switching registration for artefact removal. Adapted combinations of three reference signals recorded at the rear of the magnet could minimize the gradient artefact in all signal recordings at different positions in front of the magnet. The presented method works with any pulse sequence and any position and geometry of electrode leads loop. 3108. Fast Field Inhomogeneity and Concomitant Gradient Field Correction in Spiral Cardiac Imaging Joseph Yitan Cheng1, Juan M. Santos1,2, John M. Pauly1 1Electrical Engineering, Stanford University, Stanford, CA, United States; 2HeartVista, Inc., Los Altos, CA, United States Off-resonance blurring from main field inhomogeneities and concomitant gradient fields degrade the quality of spiral imaging. For cardiac imaging, off-isocenter acquisitions are unavoidable resulting in significant artifacts from these effects. We present the importance of correcting both the field inhomogeneity and the concomitant gradient field using two fast and accurate algorithms. The advantages of our algorithms are demonstrated in cardiac imaging: their computation speed in a real-time study and their accuracy in a high-resolution study. Matthew Ethan MacDonald1,2, Randall Brooke Stafford, 2,3, Michel Louis Lauzon, 2,4, Richard Frayne, 2,4 1Electrical and Biomedical Engineering, University of Calgary, Calgary, Alberta, Canada; 2Seaman Family MR Research Centre, Calgary, Alberta, Canada; 3Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada; 4Radiology and Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada Real time imaging requires fast acquisition and low latency reconstruction algorithms. We propose the Gradient warp and UnderSampling Transform Operator (GUSTO) algorithm as a fast method for correction of aliasing and gradient warped images using a single matrix transformation. Proof of concept is shown with low resolution (64 x 64) phantom images. 3110. Real-Time Gradient Warp Correction with OpenGL NURBS Surfaces Randall Brooke Stafford1,2, Matthew Ethan MacDonald, 2,3, Richard Frayne, 2,4 1Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada; 2Seaman Family MR Research Centre, Foothills Medical Centre, Calgary, AB, Canada; 3Department of Electrical Engineering, University of Calgary, Calgary, AB, Canada; 4Departments of Radiology and Clinical Neurosciences, University of Calgary, Calgary, AB, Canada Gradient warp correction is computationally intensive, and therefore not always practical for real-time imaging. OpenGL (Open Graphics Language) is a graphics display library with mathematical graphics functions called non-uniform rational B-splines (NURBS) that can project a 2D texture onto a 3D surface within the fast display framework. In this study, we test collected raw data in real-time and projected the resulting uncorrected image onto the NURBS surface for display. The NURBS-corrected images were then qualitatively compared to product-sequence gradient warp corrected images. Our results support our hypothesis that NURBS surfaces have the capacity for real-time non-linear gradient warp correction. Simulation in MR Teaching & Research Hall B Monday 14:00-16:00 3111. Utility of Hand-On Scanning for Assimilating MRI Concepts (Www.learnmri.org) Michelle Castro Cerilles1, Martin R. Prince1, Mitch Cooper1, Bo Xu1, Cynthia Wisnieff1, Robert Zubkoff1, Satre Stuelke1 1Radiology, Weill Cornell Medical College, New York, NY, United States Effectiveness of learning basic MRI principles by following hands-on workbook exercises as demonstrated by 11 students/residents/fellows. The workbook exercises teach MRI concepts such as MRI safety and patient screening, optimizing resolution, SNR and CNR on a phantom, optimizing T1 and T2 weighting in the volunteer brain, creating, identifying and eliminating various artifacts, adapting scanning parameters to match varying anatomy in the volunteer knee and abdomen, and implementing various approaches to minimizing respiratory motion effects. Giuseppe Palma1,2, Marco Comerci2, Anna Prinster2,3, Mario Quarantelli2, Bruno Alfano2 1ESAOTE s.p.a., Naples, Italy; 2Biostructure and Bioimaging Institute, National Research Council, Naples, Italy; 3"S.D.N." Foundation, Naples, Italy We have built and generalized a rigorous formalism of the Extended Phase Diagram algorithm, in order to coherently include within a computational framework also non-trivial dephasing effects arising from static magnetic field inhomogeneities. Computational applications are presented providing both analytical and numerical outputs, including programs evolving the state populations according to virtually any pulse sequence provided by the user. Presented examples include tools to derive in a fully automated way the analytic signal equations (developed in Mathematica®) and to simulate MR Image formation process (developed in MATLAB®). 3113. Magnetic Resonance Parameter Mapping Using Computer Simulation Yo Taniguchi1, Suguru Yokosawa1, Yoshitaka Bito1 1Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo, Japan In MR parameter mapping, parameters are estimated from images obtained with various acquisition parameters. For the estimation, the intensity function, which defines the relationship of image intensity to acquisition and MR parameters, needs to be formulated analytically in a simple form. A method to formulate the intensity function numerically by computer simulation based on Bloch equations is proposed. Intensity functions of arbitrary pulse sequences are formulated using this method so that rapid imaging is applied for the mapping. The intensity function for RF-spoiled gradient echo was formulated numerically, and we confirmed that a T1 map was successfully estimated from images obtained in a phantom experiment. 3114. Simplified Signal Equations for Spoiled Gradient Echo MRI James Grant Pipe1, Ryan K. Robison1 1Neuroimaging Research, Barrow Neurological Institute, Phoenix, AZ, United States This work presents simplified signal equations for spoiled gradient echo (SPGR) imaging. The framework introduces an exponential time constant TA, which reflects magnetization loss from the rf pulse. This framework is then used for to consider image SNR and T1 contrast. Image Segmentation Methods Hall B Tuesday 13:30-15:30 Marios C. Yiannakas1, Daniel J. Tozer1, Klaus Schmierer1, Declan T. Chard1, Valerie M. Anderson1, David H. Miller1, Claudia A.M Wheeler-Kingshott1 1UCL - Institute of Neurology, London, United Kingdom Multiple Sclerosis lesions are known to be pathologically heterogeneous but this is not well depicted on conventional MRI. In this work a new MR analysis method is presented which utilises conventional FSE dual echo data sets with the use of advanced images algebra (ADIMA). The method is an extension to a previously described technique and involves image subtraction and normalisation in order to enhance the dynamic range in the image with a consequent enhancement of lesional heterogeneity in MS lesions. The method is shown to permit classification of T2 hyper-intense lesions into bright and dark regions in a reproducible way. Sha Zhao1, Simon J. P. Meara2, Geoff J. M. Parker1,3 1ISBE, The University of Manchester, Manchester, England, United Kingdom; 2Physics Department, Clatterbridge Centre for Oncology, Merseyside, England, United Kingdom; 3Biomedical Imaging Institute, The University of Manchester, Manchester, England, United Kingdom We propose a method for obtaining 3D proportional density maps for each major brain tissue component. Using double inversion recovery (DIR), we acquire images of grey matter, white matter, CSF and proton density. Each DIR image is divided by proton density, then an optimised correction factor is calculated for each so that the sum of these ratio images is unity for all voxels, thereby correcting for inter-tissue relaxation time, and coil sensitivity confounds. These proportional density images are potentially useful for studies of brain morphology and atrophy, as demonstrated in a cohort of healthy volunteers of different ages. 3117. Method for Constructing Rapid Prototyping from MR Data Cristobal Arrieta1,2, Sergio Uribe, 2,3, Carlos Sing-Long1,2, Jorge Ramos4, Alex Vargas5, Pablo Irarrazaval1,2, Cristian Tejos1,2 1Department of Electrical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile; 2Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, Chile; 3Department of Radiology, Pontificia Universidad Catolica de Chile, Santiago, Chile; 4Department of Mechanical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile; 5Department of Surgery, Pontificia Universidad Catolica de Chile, Santiago, Chile Rapid Prototyping (RP) allows building realistic replicas of biological structures. The building process consists of acquiring imaging data, segmenting the structures of interest, triangulating the segmentation and printing. When RPs of soft tissues are built, segmentation becomes an important issue because of the low contrast between structures. Therefore, threshold, region-growing or edge-detection based segmentation tend to fail, making this process extremely tedious as important human assistance is required. We propose the use of an implicit Active Contour technique to facilitate the segmentation process. We evaluated our method by constructing an RP of a pathological heart scanned with a standard CMR. 3118. Segmentation of the Rat Hippocampal Mossy Fiber Network from MEMRI Under Inhomogenous B1 Field Way Cherng Chen1, Kai-Hsiang Chuang1 1Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore A method of segmenting the rat hippocampal mossy fiber network from MEMRI under inhomogeneous B1 field was introduced. High-pass filtering was used to correct the intensity inhomogeneity, followed by multi-level Otsu thresholding and removal of clusters with 10 or less lpixels to obtain final segmented image. High-pass filtering corrected for intensity inhomogeneity and enhanced the edges of the network making it preferable to N3 correction. Comparison with manual segmentation on 5 data sets yielded a t-value of 0.390>0.05 and a true positive rate of 91.8%. 3119. Automatic Segmentation of MR Images for Long-Bone Cross-Sectional Image Analysis Shing Chun Benny Lam1, Hamidreza Salilgheh Rad1, Jeremy Magland1, Felix W. Wehrli1 1Radiology, University of Pennsylvania, Philadelphia, PA, United States A software program has been developed to automatically segment cortical bone region from cross-sectional MR image of long bones such as the tibial shaft and extract geometric and parametric information from the segmented region. Our results show that the parameters obtained from the automatic segmentation software are in good agreement with those obtained from manual segmentation. With these parameters, the mechanical properties of the cortical bone can be quantified and analyzed over subject groups at different stages. Matthijs Christiaan van Eede1, R Mark Henkelman1, Jason P. Lerch1 1Mouse Imaging Centre, Toronto, Ontario, Canada The use of image registration to investigate shape differences in mouse brain MRIs have become a significant area of interest. It is unknown how accurately structural changes can be detected or whether this sensitivity varies with structure shape. We present a novel method to simulate deformation fields with known structural tissue change and subsequently attempt to recover the induced changes in 21 structures. We demonstrate that image based registration algorithms can reliably detect structural shape differences down to 5% in the structures with a lower surface to volume ratio, and reliably down to 10% in all others. 3121. Rapid Semi-Automatic Segmentation of the Spinal Cord from Magnetic Resonance Images Mark Andrew Horsfield1, Stefania Sala2, Mohit Neema3, Martin Absinta2, Anshika Bakshi3, Maria Pia Sormani4, Mara Rocca2, Rohit Bakshi3, Massimo Filippi2 1Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom; 2Neuroimaging Research Unit, Ospedale San Raffaele, Milan, Italy; 3Laboratory for Neuroimaging Research, Harvard Medical School, Boston, MA, United States; 4Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy A new semi-automatic method for rapid segmentation of the spinal cord from MR images is presented, based on an active surface (AS) model of the cord surface with intrinsic smoothness constraints. The intra- and inter-observer reproducibilities of cord area measures were evaluated, and compared favorably with an existing cord segmentation method. Correlations between cord area and clinical disability scores confirmed the relevance of the new method in measuring cord atrophy. A novel form of cord visualization is shown, in which the straightened cord center-line forms one coordinate axis of a new image, allowing simple visualization of the cord structure.
3122. Semi-Automated Microbleed Identification on Susceptibility Weighted Images Samuel Barnes1,2, E. Mark Haacke1 1Wayne State University, Detroit, MI, United States; 2Loma Linda University, Loma Linda, CA, United States A method to detect microbleeds in the brain in a semi-automated fashion is presented. The goal of this technique is to reduce the processing time of quantifying microbleeds. The semi-automated method compares favorably with manual counting achieving approximately 80% sensitivity and 100% specificity while reducing processing time to under an hour.
3123.
Segmentation and Volume Estimation on a Sub-Voxel Basis Using
Quantitative MR: A Validation Study 1Department of Medical and Health Sciences, Division of Radiation Physics, Linköping, Östergötland, Sweden; 2Center for Medical Imaging Science and Visualization, Linköping, Östergötland, Sweden; 3Department of Medicine and Health, Division of Clinical Physiology, Linköping, Östergötland, Sweden Using an MR quantification sequence; specific brain-tissues typically exhibit a narrow range of R1, R2 and PD values, and thus the tissues in the brain can be identified as clusters in the three dimensional R1-R2-PD space. In partial volume voxels (voxels containing two or more tissue types) the R1-R2-PD values are a combination of the values from the contributing tissues. By using a partial volume model a segmentation method to assess fractional brain-tissue volumes of white matter (WM), grey matter (GM) and CSF for the complete brain on a sub-voxel basis was created and validated on 7 normal subjects. 3124. Brain Extraction Algorithm Using 3D Level Set and Refinement Jinyoung Hwang1, HyunWook Park1 1Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea, Republic of Skull-stripping methods have been proposed widely, but they usually provide coarse segmentation results. For example, in superior and inferior slices, their results could serve incorrect result. Thus, we present a brain extraction algorithm using 3D level set and refinement process. First, 3D level set function is applied to whole brain volume, to find coarse brain region. The refinement process is then applied to the result of 3D level set function, which improves the accuracy of the final segmentation results. We evaluated the proposed method to normal brain data acquired from BrainWeb, IBSR, 1.5T, and 3T data. Marco Battaglini1, Nicola De Stefano1, Mark Jenkinson2 1Quantitative Neuroimaging Laboratory, University of Siena, Siena, Italy; 2Clinical Neurology, FMRIB Centre, University of Oxford, Oxford, Oxon, United Kingdom IIn order to develop a fully automated segmentation tool for MS lesions we explore using novel input features with two pattern classification methods (Neural Networks and Random Forests). Results show a statistically significant improvement in DICE by using the novel multi-scale and symmetry features with both classifiers. To be useful for clinical trials we use multi-centre real clinical data, segmented by different manual raters, which makes this challenging. Nonetheless, we still achieve DICE results consistent with state-of-the-art methods, without requiring costly pruning of the Neural Networks, complicated post-processing, or having to apply any exclusion criteria to the images. Seiji Kumazawa1, Takashi Yoshiura2, Hiroshi Honda2, Fukai Toyofuku1, Yoshiharu Higashida1 1Department of Health Sciences, Kyushu University, Fukuoka, Japan; 2Department of Clinical Radiology, Kyushu University, Fukuoka, Japan To study the cortical/subcortical diffusivity in neurological diseases, brain tissue segmentation methods based on DTI data have been proposed. However, a partial volume effect might complicate the segmentation. We present a brain tissue segmentation method based on DTI data. The features of our method include the conducting of the segmentation in DTI space without any registration, and the estimation of the partial volume fractions of each tissue type within a voxel using a maximum a posteriori probability principle. The results of the digital phantom experiment and human DTI data demonstrate that our method was able to perform a reasonable segmentation for brain tissue on DTI data. 3127. Characterization of Local Field Disturbances Through Phase Derivative Mapping Hendrik de Leeuw1, Mandy Conijn1, Peter R. Seevinck1, Jeroen Hendrikse2, Gerrit H. van de Maat1, Chris J.G. Bakker1 1Image Sciences Institute, Utrecht, Netherlands; 2Radiology, University Medical Center Utrecht, Utrecht, Netherlands In MRI studies, magnitude images are often used as the only source of information. Especially in the presence of local field distortions, this might be considered suboptimal, since information on the local magnetic field is encoded in the signal phase. Studies that use signal dephasing only, do not allow discrimination between paramagnetic and diamagnetic disturbances, since signal dephasing is independent of the sign of the field. We will show, by analysis of microbleeds and calcifications in the brain, that by using the phase derivative, local field disturbances can be detected and analyzed in terms of positive or negative susceptibility deviations. 3128. Detection of Abnormal Human Brain Structure from MRI Using Symmetry Features Chi-Hsuan Tsou1, Tun Jao1,2, Jiann-Shing Jeng3, Jyh-Horng Chen, 1,4 1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan; 2Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan; 3Stroke Center and Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan; 4Interdisciplinary MRI/MRS Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan Brain magnetic resonance images (MRI) is crucial in modern medical diagnoses. However, there is usually a time delay between images acquisition and interpretation of radiologists and/or doctors who prescribe the images, which may contribute to clinical exacerbation of the patients. In this preliminary study, we use symmetry index to discriminate between normal brain structures and intracranial pathologies, and to provide a foundation for images auto-alarm system in the future. Experimental results of the proposed algorithm on 24 MR images (11 pathological, 13 healthy), show that the symmetric index can help differentiate the normal and abnormal brain structures with promising performance. 3129. Automatic Detection of the Anterior and Posterior Commissures from T1-Weighted Images Islem Rekik1,2, Linda Marrakchi-Kacem1,3, Jean-Franēois Mangin1,3, Denis Le Bihan1,3, Cyril Poupon1,3, Fabrice Poupon1,3 1NeuroSpin, CEA, Saclay, France; 2ESIEE, Noisy-le-Grand, France; 3IFR49, Paris, France Frame-based interventional MRI and multi-subject image analysis often rely on the manual selection of the Anterior Commissure (AC) and the Posterior Commissure (PC) that are used to define the standard referential of Talairach. We developed a fast and fully automatic identification of the AC and PC points from T1-weighted MR images, thus leading to an automation of the image processing step during the neurosurgery planning. 3130. Objective Assessment of T2-Based Liver Lesion Classifiers Christian Graff1, Eric W. Clarkson2, Maria I. Altbach2 1Division of Imaging and Applied Math/OSEL/CDRH, U. S. Food and Drug Administration, Silver Spring, MD, United States; 2Department of Radiology, University of Arizona, Tucson, AZ, United States Classification of lesions as benign or malignant is an important imaging task. In liver, transverse relaxation time (T2) can be used as a classifier. Recently a radial fast spin-echo technique has been developed to obtain T2 estimates within a single breath-hold during which under-sampled radial k-space lines are acquired. The degree of under-sampling in this technique motivated the development of various post-processing techniques that attempt to enforce prior information to compensate for data under-sampling. In this work we evaluate these proposed algorithms through the use of a receiver-operating-characteristic (ROC) based metric which directly measures the classification performance of each algorithm. 3131. Bladder Wall Extraction and Mapping for MR Cystography Jerome Zhengrong Liang1,2, Chaijie Duan1, Xianfeng Gu2, Mark E. Wagshul1, Hongbin Zhu1, Yi Fan1, Hongbing Lu3 1Radiology, Stony Brook University, Stony Brook, NY, United States; 2Computer Science, Stony Brook University, Stony Brook, NY, United States; 3Biomedical Engineering, Fourth Military Medical University, Xian, China MRI-based virtual cystoscopy, MR cystography, T1-weighted imaging, bladder cancer, tumor recurrence, image segmentation, conformal mapping, 3-D to 2-D flattening Mark J.R.J. Bouts1, Ivo A.C.W. Tiebosch1, René Zwartbol1, Ona Wu2, Rick M. Dijkhuizen1 1Image Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 2Athinoula A. Martinos center for biomedical imaging, Massachusetts General Hospital, Charlestown, MA, United States Voxel-wise clustering of multiparametric MRI data enables classification of heterogeneous ischemic lesions into distinct categories. Previously, we have introduced a lesion clustering approach that incorporates temporal T2 and diffusion dynamics for tissue characterization. In the current study we extend this approach in an experimental subarachnoid hemorrhage model, to evaluate lesion characteristics in a treatment and control group based on temporal changes in T2, diffusion, and perfusion parameters. Five distinct signatures with different characteristics of cerebrovascular injury were identified and signature distribution revealed a different prevalence in Interferon-β treated animals compared to controls. 3133. A Multi-Anatomy System for Computing and Centering Field of View from Localizer Images Vivek Prabhakar Vaidya1, Maggie M. Fung2, Rakesh Mullick1, Robert D. Darrow3 1GE Global Research, Bangalore, Karnataka, India; 2GE Healthcare, Waukesha, WI, United States; 3GE Global Research, Niskayuna, NY, United States A system is demonstrated for automatically deriving and centering oblique scan extents/fields of view (FOV) from localizer scans. Our method differs from prior work in the field by being marker-less and allowing for automated acquisitions oblique to the input localizer. By constraining acquisition to the precise extents of the anatomy being sought acquisition time is reduced. This acquisition time reduction is particularly valuable in cardiac and abdominal imaging: given the need for breath-held scanning. Furthermore, by prescribing an optimal field of view we can also reduce potential wrapping artifacts and improve the consistency of image representation. 3134. Automated Volume of Interest Evaluation for Sequence Development Ying Wu1,2, Hongyan Du3, Fiona Malone1, Shawn Sidharthan1, Ann Ragin4, Robert Edelman1,5 1Radiology, NorthShore University HealthSystem, Evanston, IL, United States; 2Radiology , University of Chicago; 3NorthShore University HealthSystem Research Institute, IL, United States; 4Radiology, Northwestern University; 5Radiology, University of Chicago This investigation compared the standard manual region of interest approach with a volume-of-interest analysis based on automated brain segmentation. Analysis based on automated VOI successfully detected subtle changes in tissue contrast and was consistently informative for MR sequence optimization. Results based on the standard ROI approach were ambiguous in different brain regions and individuals, and failed to document changes in image quality when scanning parameters were alternated in MR sequence optimization. These findings demonstrate the potential benefit of integrating advanced quantitative image analysis into sequence development routines to improve efficiency and accuracy. Registration & Image Analysis Hall B Wednesday 13:30-15:30 Derek Magee1, Steven Frederick Tanner2, Michael Waller3, Ai-Lyn Tan4, Dennis McGonagle4, Alan Jeavons3 1School of Computing, University of Leeds, Leeds, W-Yorkshire, United Kingdom; 2Division of Medical Physics, University of Leeds, Leeds, W-Yorkshire, United Kingdom; 3Medical Physics, St James University Hospital, Leeds, United Kingdom; 4Academic Section of Musculoskelatal Disease, Chapel Allerton Hospital, Leeds, W-Yorkshire, United Kingdom A non-rigid image registration method for co-registering high-resolution PET data and MR images of the hand is described and evaluated. Employing this protocol to register synthetic data indicated a the mean registration error of less than approximately 1.5 mm. Measurements made in images acquired from patients with osteoarthritis show that the registration errors are consistent with those made in the study using synthetic data. 3136. Automated Scan Plane Planning for Brain MRI Using 2D Scout Images Suguru Yokosawa1, Yo Taniguchi1, Yoshitaka Bito1, Hisako Nagao2, Miki Tachibana2, Mutsumi Ishida2, Atsushi Shiromaru2, Hiroyuki Itagaki2 1Central Research Laboratory, Hitachi, Ltd., Kokubunji-shi, Tokyo, Japan; 2Hitachi Medical Corporation, Kashiwa-shi, Chiba, Japan We propose a faster automated scan plane planning method for the brain using 2D multi-slice orthogonal three-plane scout images. Our algorithm based method, uses 2D scout images, which can be acquired rapidly. Furthermore, our algorithm can prescribe scan plane faster than other method that use 3D data due to the smaller 2D data size. We applied our proposed method to healthy volunteers, and compared automatically defined scan plane position with those manually defined. The results showed that our method prescribed scan planes quickly and with acceptable accuracy in clinical practice. 3137. Quantitative and Local Mouse Brain Morphometry in Longitudinal MRI Studies Alize Elske Hiltje Scheenstra1, Dana Suciu2, Michael Muskulus3, Melly S. Oitzl4, Johan H.C. Reiber1, Louise van der Weerd5, Jouke Dijkstra1 1Radiology, image processing, LUMC, Leiden, Netherlands; 2Radiology, LUMC, Leiden, Netherlands; 3Mathematical Department, Leiden University, Leiden, Netherlands; 4LACDR, Leiden University, Netherlands; 5Department of Anatomy and Embryology, LUMC, Leiden, Netherlands We present the Moore-Rayleigh (MR) test as nonparametric statistical test for longitudinal brain MRI deformation based morphometry: A group of male mice (n=10) was followed during exposure to the stress hormone hormone corticosterone for 2 weeks and a recovery period of 1 week. The results of the MR test are comparable to volumetric based morphometry, but it enriches the analysis with its ability to detect also localized shape changes, which are still significant under Bonferroni correction. 3138. Type I Errors in Whole Brain Voxel-Wise Analyses David Matthew Carpenter1, Cheuk Ying Tang1,2 1Radiology, Mount Sinai School of Medicine, New York, United States; 2Psychiatry, Mount Sinai School of Medicine, New York, NY, United States Voxel based analysis or Statistical Parametric Mapping (SPM) yields inconsistent results across studies. It is difficult to challenge the validity of SPM results in published works and review submissions because the nature of the immense datasets that underlie VBA results prohibits its presentation in journals. In this abstract we use a simple data set to explore sources of type I errors in areas that often yield positive results and present findings that can serve as a guide for critiquing these SPM presentations. 3139. Propagation-Based Morphometry in an Ex Vivo Mouse Embryo Atlas Assessment and Validation Francesca C. Norris1,2, Jon O. Cleary1,3, Marc Modat4, Anthony N. Price1, Karen McCue5, Sarah Beddow5, Peter J. Scambler5, Sebastien Ourselin4, Mark F. Lythgoe1 1Centre for Advanced Biomedical Imaging, Department of Medicine and UCL Institute of Child Health, University College London, London, United Kingdom; 2Centre for Mathematics and Physics in the Life Sciences and EXperimental Biology (CoMPLEX), University College London, London, United Kingdom; 3Department of Medical Physics and Bioengineering, University College London, London, England, United Kingdom; 4Centre for Medical Image Computing, University College London, London, United Kingdom; 5Molecular Medicine Unit, UCL Institute of Child Health, University College London, London, United Kingdom The increasing use of genetically modified mice has highlighted the need for effective phenotyping methods. Propagation-based morphometry (PBM) is an emerging technique enabling non-invasive and rapid acquisition of volumetric data using an average population atlas for morphometric analysis. Thus, PBM shows promise for combining high-throughput µMR imaging of late-gestation embryos with high-throughput analysis. We present the first study to assess and validate the accuracy of volumes generated via PBM in an ex vivo mouse embryo atlas comprising three different groups. Preliminary results show promise towards the broad applicability of this technique for phenotyping mutant mouse models. 3140. A New Approach to Mouse Brain Mapping Marianne Dorothea Keller1,2, Charles Watson3, Kay Richards4, Rachel Buckley5, Nyoman Kurniawan6, Richard Beare5, Jana Vukovic2, Deming Wang1, Steven Yang1, Peter Zhao7, Nathan Faggian4, George Paxinos7, Steven Petrou4, Gary Egan4, Perry Bartlett2, Graham Galloway1, David Reutens8 1Centre for Magnetic Resonance, University of Queensland, Brisbane, Qld, Australia; 2Queensland Brain Institute, University of Queensland, Brisbane, Qld, Australia; 3Curtin University, Perth, WA, Australia; 4Florey Neuroscience Institutes, Melbourne, Vic, Australia; 5Monash University, Melbourne, Vic, Australia; 6Centre for Magnetic Resonance, University of Queensland, Brisbane,, Qld, Australia; 7Prince of Wales Medical Research Institute, Sydney, NSW, Australia; 8Centre for Advanced Imaging, University of Queensland, Brisbane, Qld, Australia When working with mouse brain models it becomes apparent, that anatomically detailed, three dimensional atlases are not readily available. On one hand, histological atlases are two dimensional, whereas three dimensional MRI atlases might only define 40 brain structures. Our aim is to create an digital atlas using high resolution images produced by a 16.4 T MRI scanner, complemented by histological data. A higher grade of segmentation, for example 45 structures in the cerebellum and 35 in the hippocampus, will enable the researcher to compare normal mouse brain anatomy to pathological anatomical changes in models of disease.
3141. Developmental Changes in the Shape of Hippocampus in Children Aged from 6 to 9 Years Old Muqing Lin1, Lutfi Tugan Muftuler1, Ke Nie1, Kevin Head1, Claudia Buss2, Elysia Poggi Davis2, Curt A. Sandman2, Orhan Nalcioglu1, Min-Ying Lydia Su1 1Tu & Yuen Center for Functional Onco-Imaging, University of California, Irvine, Irvine, CA, United States; 2Department of Psychiatry and Human Behavior, University of California, Irvine, Irvine, CA, United States The shape analysis of hippocampus was commonly applied to evaluate the progression of atrophy pattern in elderly patients, and in this study it was applied to evaluate the changes in developmental brain in 48 children. The distance from the hippocampal surface to the central line was mapped to a 2D grid for statistical analysis. The Permutation and t-test was applied to compare two age groups (6-7 vs. 8-9 y/o), and the regression analysis with age was also performed. Significant differences were found in small areas of CA1 and subiculum; however, overall there is not a strong age dependence. KOJI SAKAI1, Susumu Mori2, Kenichi Oishi2, Andreia Faria2, Naozo Sugimoto 1Kyoto University, Kyoto, Japan; 2Johns Hopkins University The VBA is one of the most effectual assessment methods of the entire white matter of brain. However, the VBA often suffers from high false discovery rate which caused by embedded noise in voxels and imperfect registration. On the other hand, 3D whole brain WM atlas (ABA: atlas-based analysis) was proposed to achieve statistical power on the examination of the WM analysis. We also have proposed alternative way to analyse WM by sub-atlas based analysis (SBA). In this paper, we attempted to ascertain the statistical detection power and the features of VBA, ABA, and SBA. 3143. Accelerating the Image Registration of MRI Volumes by Modern GPGPU Parallel Computation Shiun-Ying Ju1, Yu-Wei Tang1, Teng-Yi Huang1 1Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan Image registration has been an important topic in the MRI applications, such as longitudinal follow-up studies, brain-normalization for group statistics and motion correction for fMRI studies. However, the automatic registration requires a lot of iteration loops and a huge amount computation for linear transformations and thus it is generally very time-consuming task. In our study, we proposed to use the parallel computing on recently advanced general-purpose computation on graphic processing units (GPGPU) to accelerate the registration calculations, especially for the popular SPM system. We got about 23-fold acceleration of the computation process on our datasets. Sebastian Kurtek1, Eric Klassen2, Anuj Srivastava1, Zhaohua Ding3,4, Sandra W. Jacobson5, Joseph L. Jacobson5, Malcolm J. Avison3,4 1Department of Statistics, Florida State University, Tallahassee, FL, United States; 2Department of Mathematics, Florida State University, Tallahassee, FL, United States; 3Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States; 4Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States; 5Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, United States Shape analysis of anatomical structures is central to medical diagnosis, especially when using MRI data. We propose a novel Riemannian framework for analyzing shapes of 3D brain substructures (e.g. putamen). This framework provides metrics that are invariant to rigid motion, scaling and most importantly parameterizations of surfaces (placements of meshes). The metric is evaluated by a gradient-based alignment of meshes for the surfaces being compared. Consequently, the distance between identical surfaces with different meshes is zero. We present results of this methodology applied to comparisons of left putamens across subjects and to classification of subjects with prenatal exposure to alcohol. Jelle Veraart1, Bjornar T. Antonsen2, Ines Blockx3, Wim Van Hecke4,5, Yi Jiang6, G. Allen Johnson6, Annemie Van Der Linden3, Trygve B. Leergaard2, Marleen Verhoye3, Jan Sijbers1 1Vision Lab, University of Antwerp, Antwerp, Belgium; 2Center for Molecular Biology and Neuroscience, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway; 3Bio Imaging Lab, University of Antwerp, Antwerp, Belgium; 4Department of Radiology, University Hospital Antwerp, Antwerp, Belgium; 5Department of Radiology, University Hospitals of the Catholic University of Leuven, Leuven, Belgium; 6Duke Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States An anatomically labeled DTI atlas of the adult Sprague Dawley brain is proposed. The atlas is constructed using a population based atlas construction approach to create a template which represents the average anatomy. Further, a bias to a single subject is minimized. During the construction, a non-rigid coregistration technique is used to avoid local misalignment inaccuracies due to intersubject differences. The delineation of brain structures was performed on high resolution ex-vivo scans and the resulting parcellation maps were non-linearly warped into the in-vivo atlas space afterwards. The atlas is perfectly suited for automated ROI analysis and more standardized VBA studies. 3146. Comprehensive Digital 3D Monkey Brain MRI Atlas Tina Jeon1, Takashi Yoshioka2, Steven Hsiao2, Stewart Hendry2, Hao Huang1 1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Mind and Brain Institute, Johns Hopkins University, Baltimore, MD, United States Due to their close relationship to the human brain, animal models of primates have been unique and irreplaceable in neurobiological studies. In these studies, atlases have played central roles as anatomical references. However, few atlases are 3D, digital, or have comprehensive gray and white matter labeling. In this abstract, we show the digital atlas with complete labeling of cortical gyri, subcortical nuclei and white matter tracts with high resolution DTI. The digital format of the atlas makes it possible to map the labeling information of the atlas to the experimental monkey brain with image registration. Lauren Jean Bains1,2, Josephine H. Naish1,2, David L. Buckley3 1Imaging Science and Biomedical Engineering, School of Cancer and Imaging Sciences, University of Manchester, Manchester, Greater Manchester, United Kingdom; 2University of Manchester Biomedical Imaging Institute, University of Manchester, Manchester, Greater Manchester, United Kingdom; 3Division of Medical Physics, University of Leeds, Leeds, United Kingdom Quantitative DCE-MRI benefits from the use of individual patient AIFs, however, accurate MRI-based AIF measurements are complicated by partial volume and inflow effects. We tested two methods of AIF correction based on cardiac output, and evaluated their effects on DCE-MRI tracer kinetic parameter estimates by comparing these estimates with DCE-CT, a modality which is unaffected by many of the artefacts that are problematic in DCE-MRI. Our results show that the use of cardiac output to correct DCE-MRI produces parameter estimates which are significantly closer to DCE-CT with reduced variance; the use of such corrections may significantly benefit DCE-MRI analyses. 3148. A Novel Method for Automatic Estimation of M0 Used by ASL CBF Quantification Ognjen Zivojnovic1, Greg Zaharchuk2, Ajit Shankaranarayan3 1Stanford University, Stanford, CA, United States; 2Department of Radiology, Stanford University, Stanford, CA, United States; 3Applied Sciences Laboratory - West, GE Healthcare, Menlo Park, CA, United States Calculating quantitative CBF values based on ASL images requires knowledge of M0. Two models exist for estimating its value, a blood based model that depends on the M0 of CSF, and a tissue based model that requires the re-imaging of the entire volume. This abstract presents a novel method for automatically estimating M0 based on the blood model in order to take advantage of its faster scan times compared to the tissue based model, as well as to remove human inconsistencies in selecting the area from which the estimate is made. Min Sun1,2, Xuedong Yang3, Dongjiao Lv4, Mingyuan Xie2, Ling Yang2, Chengbo Wang5, Xiaoying Wang, 1,3, Jue Zhang, 1,4, Jing Fang, 1,4 1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China; 2Dept. of Electronic Engineering, Chengdu University of Information Technology, Chengdu, Sichuan, China; 3Dept. of Radiology, Peking University First Hospital, Beijing, China; 4College of Engineering, Peking University, Beijing, China; 5Dept. of Radiology, University of Virginia, Charlottesville, Virigina, United States Early detection of liver nodular lesions is critical in improving patient”Æs survival rate. Previous studies have shown that for dynamic contrast-enhanced MR imaging of liver nodules, there exists correlation between nodules”Æ blood supplies and MR signal changes. In this retrospective study, haemal supplies correlation based strategy was introduced to identify the suspected hepatic nodules, including DN, RN and SHCC from dynamic contrast-enhanced MR Images, and the analysis results were in consistence with the clinical diagnosis under double-blind test. The proposed computer aided identification approach could be helpful to provide valuable information for the detection of hepatic nodules. Gregor Thörmer1, Nikita Garnov1, Jürgen Haase2, Thomas Kahn1, Michael Moche1, Harald Busse1 1Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany; 2Physics and Geosciences Department, Leipzig University, Leipzig, Germany MR-visible markers have many potential applications such as an automated mapping of coordinate systems (image/patient registration), stereotactic planning/monitoring of procedures, and the localization/tracking of devices inside the magnet. In this work, precision, accuracy and update rates of a fully automatic marker localization based on morphologic image processing have been studied experimentally as well as theoretically (simulation) as a function of the underlying pixel size. The moderate 3D errors (”Ö1 mm) observed for the fastest sequence (pixel dimension 4.7 mm) clearly demonstrate that the presented technique does not necessarily require highly resolved images of the markers (physical dimension ”Ö4 mm). 3151. Automatic MRI Acquisition Parameters Optimization Using Perceptual Criteria Javier Jacobsen1,2, Sergio Uribe, 2,3, Cristian Tejos1,2, Carlos Sing-Long1,2, Pablo Irarrazaval1,2 1Department of Electrical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Chile; 2Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, Chile; 3Department of Radiology, Pontificia Universidad Catolica de Chile, Santiago, Chile The visualization of structures in MRI highly depends on many user defined scan parameters. The selection of them is always done heuristically and requires a vast experience from the operator. We propose a methodology based on an automatic optimization to find the MRI acquisition parameters that maximize the visibility of a desired structure. The objective function of our optimization is computed from Visibility Maps (VM) that are designed to measure the visibility of structures according a perceptual criteria. The method was tested on brain MRI experiments and the optimal parameters found by our method are in excellent agreement with those found by experienced radiologists. 3152. A Stochastic Framework for Improving the Accuracy of PIESNO Cheng Guan Koay1, Evren Ozarslan1, Carlo Pierpaoli1, Peter J. Basser1 1NIH, Bethesda, MD, United States Probabilistic Identification and Estimation of Noise (PIESNO) is a recent technique capable of identifying noise-only pixels in magnitude-reconstructed MR images. The identification criterion and the estimation method used in PIESNO were chosen and constructed for expediency in terms of computational efficiency and theoretical simplicity rather than for accuracy. Although a strictly theoretical approach to determine the exact level of bias in the estimate of noise level through PIESNO seems to be intractable, it is still worthwhile to use stochastic framework for determining the level of bias. Here, we present one such framework for improving the accuracy of PIESNO. 3153. Comparison of SNR Calculation Methods for in Vivo Imaging Bing Wu1, Chunsheng Wang1, Yong Pang1, Xiaoliang Zhang1,2 1Radiology&Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States; 2UCSF/UC Berkeley Joint Group Program in Bioengineering, CA, United States Local and global SNR of in vivo MR images are often measured to evaluate the image quality. Due to the density variation of in vivo images, the motion during the acquisition and other aspects, the SNR measurement of the in vivo image, especially at high field MRI, is much more complicated. The purpose of this work is to evaluate and compare SNR calculation methods to provide the reference or guidance for in vivo image SNR measurements. 3154. Consistency Assessment for R2* Measurements Obtained with Different Techniques at 7 Tesla Xiangyu Yang1, Petra Schmalbrock1, Michael V. Knopp1 1Department of Radiology, The Ohio State University, Columbus, OH, United States At high and ultrahigh field, R2* measurement can be dependent on the technique used due to non-exponential FID distortions caused by various factors. In this study, we compared R2* measurements obtained with three different techniques in a group of four healthy volunteers at 7 Tesla to assess their consistency. Our results demonstrate that R2* values measured with a 2D imaging technique is only comparable with those from a 3D technique when appropriate correction for the background field inhomogeneity effect is applied. 3155. Analysis of Abdominal Fat Tissue Images Acquired with Continuously Moving Table MRI Stathis Hadjidemetriou1, Juergen Hennig1, Florian Klausmann1, Ute Ludwig1 1Department of Diagnostic Radiology, University Hospital Freiburg, Freiburg, Germany The risk for hypertension and diabetes is correlated closely to the amount of visceral fat. In this work, the abdominal fat is imaged with a continuously moving table whole body MRI technique. A method is presented for the repeatable, general, and reliable differentiation of lipids into subcutaneous and visceral. The data is restored for intensity uniformity. The corrected image is processed to segment the body region with the graph cuts algorithm operating on level sets. Then, the contour separating the subcutaneous and visceral fat regions is identified with a combination of the random walks algorithm and graph cuts. 3156. Fast Fat/Water Decomposition Using GPU Computation and Newton's Method David Johnson1, Sreenath Narayan2, Chris Flask, 2,3, David Wilson2,3 1Heart and Lung Research Institute, Ohio State University, Columbus, OH, United States; 2Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; 3Radiology, University Hospitals of Cleveland, Cleveland, OH, United States An improved fat/water estimation technique was developed using Iterative Decomposition of Water and Fat with Echo Asymmetry and Least-squares estimation method and Graphics Computational Units (IDEAL-GPU). The IDEAL-GPU technique produced robust fat and water images quickly and efficiently using a vectorized equation implemented on graphics cards. In addition, our implementation used binary weighted planar extrapolation for robust estimation in the face of large field variations on a high field, small animal scanner. Fast computation will become even more significant as the trend towards high resolution, whole body mouse and human scanning continues. 3157. Case-PDM Optimized Compressed Sensing Sampling for Fat-Water Separation Sreenath Narayan1, Jun Miao1, Fangping Huang1, David Johnson2, Guo-Qiang Zhang1, David Wilson1 1Case Western Reserve University, Cleveland, OH, United States; 2Ohio State University, Columbus, OH, United States Compressed Sensing for 3 point Dixon method source image reconstruction has not yet been optimized for perceptual performance. In this abstract, we determine how to densely to sample each of the source images to achieve a given global sampling ratio. 3158. Comparison of Compressed Sensing and Keyhole Methods for Fat-Water Separation Sreenath Narayan1, Jun Miao1, Fangping Huang1, David Johnson2, Guo-Qiang Zhang1, David Wilson1 1Case Western Reserve University, Cleveland, OH, United States; 2Ohio State University, Columbus, OH, United States Dixon-type methods require multiple scans with different chemical shift weights. Keyhole methods have previously been used to reduce scan time. In this abstract, we compare keyhole methods and Compressed Sensing for quantitative studies. Brain Image Analysis Hall B Thursday 13:30-15:30 Daniel J. Tozer1, Declan Chard1, Olga Ciccarelli2, Benedetta Bodini2, David H. Miller1, Alan J. Thompson2, Claudia Angela Michela Wheeler-Kingshott1 1NMR Unit, Department of Neuroinflammation, UCL Institute of Neurology, London, United Kingdom; 2Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom The definition of areas of grey matter (GM) that are associated with specific white matter tracts is important for studies investigating the spatio-temporal relationship between the two. The work proposes a method for extending a white matter tract calculated from diffusion MRI through the GM using a geometrical extension of those pixels on the tract edge, which are in or abut GM, to the nearest point on the outer GM boundary. It was found that running the extension in 3 orthogonal 2D planes included more tissue than running the process in 3D, which may be preferable in many cases. 3160. New Invariant Indexes to Quantify Water Anomalous Diffusion in Brain Silvia De Santis1,2, Silvia Capuani1,2, Andrea Gabrielli3,4, Bruno Maraviglia, 1,5 1Physics department, Sapienza University, Rome, Italy; 2INFM-CNR SOFT, Sapienza University, Rome, Italy; 3SMC - CNR/INFM, Sapienza University, Rome, Italy; 4ISC - CNR, Rome, Italy; 5Neuroimaging Laboratory, S. Lucia Foundation, Rome, Italy We propose a new procedure to detect the deviation from the mono-exponentiality of water diffusion in brain. The stretched-exponential model has been extended to three-dimensional space to obtain new scalar invariants. The potentiality of this methodology has been evaluated on young healthy subjects. Statistical analysis on selected ROIs from different cerebral tissues underlined a different contrast compared to conventional DTI one. In particular, GM and WM can be discriminated on the basis of their microstructural complexity, underlying a chance for investigating subtle changes of the water diffusive motion in tissues which are not detected by conventional MD and FA indexes. Yung-Chin Hsu1, Ching-Han Hsu2, Wen-Yih Tseng3 1National Tsing Hua University, Hsin-Chu, Taiwan; 2National Tsing Hua University, Taiwan; 3Center for Optoelectronic Biomedicine and Department of Medical Imaging Problems of image registration has been well studied in the neuroimaging field. However, the registration of the diffusion MRI data, especially to align the fiber orientations among different brains, is not readily applicable using current available packages. We generalized the conventional 3D registration to the 6D scenario by implementing LDDMM algorithm. The results demonstrate the proposed method is applicable for the registration between DSI datasets. 3162. Cortical Shape Analysis Using Spherical Wavelet Decomposition of Curvature Kim Mouridsen1,2, Rudolph Pienaar3,4 1Neuroradiology, Center for Functionally Integrative Neuroscience, Aarhus, Denmark; 2Radiology, Massachusetts General Hospital, Boston, MA, United States; 3Radiology, Childrens Hospital Boston, Boston, MA, United States; 4Radiology, Harvard Medical School, Boston, MA, United States We present a method to analyze cortical shapes based on wavelet decomposition of curvature functions. Using spherical harmonics as effective encoding, we show that groups of healthy controls and patients suffering from polymicrogyria may be identified using automated classification techniques. 3163. Is Quantitative T2 Sensitive to Tumor Cell Infiltration? Tonima Sumya Ali1, Thorarin Bjarnason1, Beichen Sun1, Xueqing Lun1, Donna Senger1,2, Peter Forsyth1,3, Jeff Dunn1,4, Joseph Ross Mitchell1,3 1University of Calgary, Calgary, Alberta, Canada; 2Tom Baker Cancer Centre; 3Southern Alberta Cancer Research Institute; 4Hotchkiss Brain Institute Quantitative analysis of multi-echo T2 relaxation has been used to examine micro compartmental structures in rat glioblastoma tumors. The infiltrative nature of malignant gliomas poses a major clinical challenge in rendering tumors incurable by conventional techniques. Recently, brain tumor initiating cells (BTIC) have been hypothesized to represent the cell of origin for these tumors. We analyzed 5 mouse brains in vivo inoculated with BTIC to characterize the changes in T2 distributions for each heterogeneous tumor. Based on the qualitative comparison between segmented geometric mean T2 map and histology staining, 4 regions were identified that corresponded to varying tumor cell densities. |