Sara Maria Sprinkhuizen¹, Jerome Ackerman¹, and Yi-Qiao Song^1,2
1MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, ²Schlumberger-Doll Research, Cambridge, MA, United States

Decay due to Diffusion in the Internal Field (DDIF) MRI measures solid trabecular bone structures. Bone marrow plays an important role in DDIF MRI: the magnetic susceptibility of marrow fat induces field gradients in the pore spaces which depend on the water-fat ratio and spatial distribution of the fat cells within the pores. In this work we assessed whether DDIF MRI technique may be used to detect bone marrow alterations and diseases. As a first step towards this goal, we simulated the effect of the spatial distribution of marrow fat cells on the DDIF MRI signal for 3 clinical cases.

Mary Kate Manhard^1,2, Robert Adam Horch^2,3, Daniel F Gochberg^2,3, Jeffry S Nyman⁴, and Mark D Does^1,2
1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, ²Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ³Radiology & Radiological Sciences, Vanderbilt University, Nashville, TN, United States, ⁴Department of Orthopaedics & Rehab, Vanderbilt University, Nashville, TN, United States

The previously proposed DAFP and AIR sequences were applied to in vivo clinical scans on three human subjects on the wrist and the lower leg. Bound and pore water concentration maps were obtained from the images on cortical bone of the radius and tibia. Each scan was repeated three times and the reproducibility was investigated as the inter-scan variability. Good repeatability was found (≈10% standard error per ROI), verifying these methods as diagnostic tools for assessing bone quality.

Lindsey Alexandra Crowe¹, Nicolas Kunz², Iris Friedli¹, Azza Gramoun¹, Kerstin Grosdemange¹, Curtis A Corum³, Rolf Gruetter², and Jean-Paul Vallée^1
1Division of Radiology, Geneva University Hospitals, Geneva, Switzerland, ²Laboratory of Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, ³Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, United States

Sweep Imaging with Fourier Transform (SWIFT) imaging at 14 T shows short T2 bone matrix structure in an antigen-induced arthritis (AIA) model in rat. This technique is compared to gradient echo where bone structures appear dark. We explore the advantages SWIFT to assess bone matrix and erosion in the first feasibility study for small rodent joints at 14 T.

Atena Akbari^1,2, Shahrokh Abbasi Rad^1,2, Mohsen Shojaee Moghaddam³, and Hamidreza Saligheh Rad^1,2
1Medical Physics and Biomedical Engineering Department, Tehran University of Medical Sciences, Tehran, Tehran, Iran, ²Quantitative MR Imaging and Spectroscopy Group, Research Center for Molecular and Cellular Imaging, Tehran, Tehran, Iran, ³Imaging Center, Payambaran Hospital, Tehran, Tehran, Iran

Larger pores in human cortical bone (>30 µm) have essential role in its mechanical competence, suggesting to quantify such proton pools as a reliable measure of cortical bone porosity and thus, cortical bone quality. Signal from such pores can be reliably captured using short echo time (STE) pulse sequence with echo-time in range of 0.5-1msec. Furthermore, it is well-known that cortical bone T1-relaxivity is a function of its geometrical characteristics, suggesting subject-dependent cortical bone free water increasing with age. In this work, we investigated relationship between STE-based cortical bone T1-values and age, studies in a group of healthy volunteers at 1.5T.

Musa Zaid¹, Drew Lansdown¹, Karupppasamy Subburaj², C. Benjamin Ma¹, Richard Souza², and Xiaojuan Li^2
1Orthopaedic Surgery, University of California San Francisco, San Francisco, California, United States, ²Radiology and Biomedical Imaging, University of California San Francisco, California, United States

Magnetic resonance imaging is an appealing approach for measuring knee kinematics. We have developed a novel combined tibial and femoral algorithm for determining MR-based knee kinematic measurements. Tibial and femoral coordinate systems were established from bone segmentations and used to establish coordinate systems to measure anterior tibial translation and internal tibial rotation. Using this novel method, knee MR images from five subjects were segmented by two independent researchers. Intra-class correlation coefficient measurements exhibited excellent inter-user and intra-user reliability of this combined registration method over a tibial only based approach.

R.A. van der Heijden^1,2, D.H.J. Poot^1,3, E.E. Bron¹, S. Klein¹, J.A.N. Verhaar⁴, S.M.A. Bierma-Zeinstra^2,4, M. van Middelkoop², G. Kotek¹, and E.H.G. Oei^1
1Radiology, Erasmus Medical Center, Rotterdam, Netherlands, ²General Practice, Erasmus Medical Center, Rotterdam, Netherlands, ³Imaging Science and Technology, Delft University of Technology, Delft, Netherlands, ⁴Orthopedics, Erasmus Medical Center, Rotterdam, Netherlands

Quantitative dynamic contrast-enhanced MRI (DCE-MRI) has the potential to advance the knowledge on the pathogenesis of bone diseases, such as PFPS, by measuring blood perfusion in bone quantitatively. However, there is no consensus regarding optimal analysis methods and pharmacokinetic model and there is no tailored method for the patellofemoral joint yet. We developed a tailored method for the patellofemoral joint. The results suggest that our tailored DCE-MRI protocol and post-processing tool successfully extract the dynamic contrast enhancement from the measurements, and thus can be used to study patellar blood perfusion.

Silvia Capuani¹, Rebuzzi Mauro², Vincenzo Vinicola³, Umberto Sabatini⁴, and Marco Bozzali^5
1Physics Department, CNR IPCF Roma "Sapienza " University, Rome, Rome, Italy, ²Physics Department, Physics Department Sapienza University, Rome, Italy,³Rehabilitation Hospital, IRCCS Santa Lucia Foundation, Rome, Italy, ⁴Radiology Department, IRCCS Santa Lucia Foundation, Rome, Italy, ⁵Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy

We have investigated water ADC changes in calcaneal cancellous bone of healthy subjects characterized by a large age range (22-69 y) and of osteopenic and osteoporotic patients at 3.0T employing DWI to quantify ADC and MRS techniques to quantify marrow fat content. ADC data from human calcanei shows the ability of diffusion measurement to obtain complementary information, compared to those provided by BMD, for investigating cancellous bone quality.

Luning Wang¹ and Qun Zhao^1
1Department of Physics and Astronomy, University of Georgia, Athens, GA, United States

Bone diseases have influenced millions of people’s lives, and MR imaging of bone is thus important and has attracted attentions of researchers and clinicians for a long time. However, bone imaging still remains a challenge for MRI, as bone, especially cortical bone, has a relatively short T2 and T2* values, which results in a fast signal decay. In this work, we aim to conduct a preliminary study to image free water stored in a sample of a swine humerus bone by using the fast spin echo (FSE) sequence and the sweep imaging using Fourier transformation (SWIFT) sequence. To get a qualitative mapping of free water distribution in the bone, MR scans were performed before and after dehydration of the sample, with fat and water saturation applied. The results demonstrate that the SWIFT sequence has an advantage on visualizing cortical bone compared with the FSE sequence, especially on visualizing bound water component in cortical bone.

Yasuhiko Terada¹, Shinya Inamura¹, Katsumi Kose¹, Ryo Miyagi², Yasunari Fujinaga², and Hiroshi Yoshioka^2
1Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan, ²Department of Radiological Sciences, University of California Irvine, Orange, CA, United States

Skeletal age can often be evaluated by assessing the maturity of 13 bones in the left hand and wrist of MR images. We have developed a portable hand scanner, which requires no shielding room, occupies only a small fraction of the space, and enables skeletal age examination in remote place. However, the available FOV size is limited and it requires several scans to image all the bones necessary for the skeletal age assessment. In this study, we limit the target bones to phalanges which can be imaged in one scan, and assess the skeletal age based on MR images of the phalanges alone.

Doron Cohn Yakubovich¹, Uzi Eliav², Michal Rivlin², Ilan Kallai¹, Gadi Pelled^1,3, Dan Gazit^1,3, Zulma Gazit^1,3, and Gil Navon^2
1Skeletal Biotech Laboratory, The Hebrew University of Jerusalem, Jerusalem, Israel, ²School of Chemistry, Tel Aviv University, Tel Aviv, Israel, ³Department of Surgery, Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, California, United States

In order to examine parathyroid hormone (PTH, a bone anabolic agent) effect on scar tissue formation at calvarial bone grafts proximity, we used MRI scanning protocol, consisted of MTC and double quantum filtering to measure collagen fiber deposition in the scar-bone suture. We hypothesize that this quantitative MRI technique for evaluating collagen deposition will confirm that PTH administration decreases collagenous scar tissue formation. Indeed, in- and ex-vivo MRI revealed changes in collagen as in comparison to the control animals, enabling differentiation between new bone formation and scar tissue. Our technique will enable physicians longitudinal, non-invasive follow up of various fibrosis related conditions.

Allegra Conti¹, Raffaele Sinibaldi¹, Silvia Capuani², Tonino Traini³, Gian Luca Romani^1,4, and Stefania Della Penna^1,4
1Department of Neuroscience and Imaging, University of Chieti, Chieti, CH, Italy, ²Department of Physics, Sapienza University of Rome, Rome, RM, Italy, ³Department of Stomatology and Biotechnologies, University of Chieti, Chieti, CH, Italy, ⁴Institute of Advanced Biomedical Technologies, University of Chieti, Chieti, CH, Italy

The use of biomaterials scaffolds for bone regeneration/augmentation represents one of the most used strategies in dentistry to support prosthetic restorations. Often implant failure can be associated to the trabecular bone quality of the jaw. Here we present a new method based on the co-registration of images of scaffold collected with the X-ray Synchtron Radiation-microCT and micro-MRI, that permit to obtain a complete and 3D characterization of scaffolds, distinguishing unambiguously different degrees of bone mineralization, multinucleate cells and blood vessels inside the bone marrow. Until now this was possible only with an histological, and so bidimensional, evaluation of the samples.

Angel Torrado-Carvajal^1,2, Juan A. Hernandez-Tamames^1,2, Joaquin L. Herraiz², Yigitcan Eryaman^2,3, Yves Rozenholc⁴, Elfar Adalsteinsson^5,6, Lawrence L. Wald^3,6, and Norberto Malpica^1,2
1Dept. of Electronics, Universidad Rey Juan Carlos, Mostoles, Madrid, Spain, ²Madrid-MIT M+Vision Consortium in RLE, MIT, Cambridge, Massachusetts, United States,³Dept. of Radiology, MGH, Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States, ⁴MAP5, CNRS UMR 8145, University Paris Descartes, Paris, Paris, France, ⁵Dept. of Electrical Engineering and Computer Science, MIT, Cambridge, Massachusetts, United States, ⁶Harvard-MIT Health Sciences and Technology, MIT, Cambridge, Massachusetts, United States

MRI-based bone segmentation is a challenging but important task for accurate construction of patient-specific models. We propose a method for complete skull segmentation based only on T1-weighted images of the human head. The skull is estimated using a multi-atlas (CT database) segmentation and label-fusion approach. CTs are elastically registered to the patient MRI image and thresholded. Then, the patient-specific skull is estimated using label-fusion algorithms. The method was tested in 12 healthy subjects; a radiologist evaluated and considered all the segmentations as accurate. The results may allow removing CT acquisitions in several protocols, thus decreasing patient ionization.

Yi-Xiang Wang¹, David KW Yeung¹, Min Deng¹, Jing Yuan¹, and James F Griffith^1
1Dept Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong

Lumbar spine bone mineral density (BMD) with quantitative CT, marrow fat fraction (FF) and marrow perfusion using MRS and DCE MRI at the L3 vertebra in 6 females underwent hysterectomy and bilateral salpingo-oophorectomy were performed. Reduced BMD, increased marrow FF, and reduced marrow perfusion occurred in synchrony. There was a sharp decrease of 12.5±7.2% for BMD (n=6), a sharp increase of 92.2±46.3% (n=6) for FF, a sharp decrease of 23.6±3.9% for maximum enhancement (n=5), and of 45.4±7.7% for enhancement slope (n=5) during the initial 3 months post surgery. These changes occurred at a slower rate during the later follow-up period.

Eric Y Chang¹, Graeme M Bydder², Sheronda Statum², Chantal Pauli^3,4, Merissa Olmer⁴, Darryl D'Lima⁴, and Christine B Chung^1
1Department of Radiology, VA San Diego Healthcare System, San Diego, CA, United States, ²Department of Radiology, University of California, San Diego Medical Center, San Diego, CA, United States, ³Department of Pathology, University Hospital Zürich, Zürich, Switzerland, ⁴Scripps Healthcare, San Diego, CA, United States

Crimps is a feature of collagenous tissues that has biomechanical significance. Utilizing ultra-high field strength MRI (11.7T), human crimp morphology is visible for the first time. Additionally, we provide the first description of macroscopic crimps (macrocrimps) on MRI with histologic correlation, which are visible in unloaded tendon on 3T MRI. Macrocrimps change tendon signal intensity and can potentially alter T2 measurements of tendons between loaded and unloaded states.

Diego A Garcia¹, Higor Grando¹, Kenyu Iwasaki¹, Reni Biswas¹, Sheronda Statum¹, Eric Y Chang¹, Graeme M Bydder¹, and Christine B Chung^1
1Radiology, VA San Diego Healthcare System - UCSD, San Diego, California, United States

The plantar plate has been identified as a major stabilizer structure of the metatarsophalangeal joint. The purpose of the study is to provide high-resolution and quantitative MR evaluation of the first MTP joint. Imaging of the first MTP joints were performed on 3T and 11.7T MR system of five cadaveric forefeet, and each specimen were subsequently correlated with gross and histologic anatomy. Through high-resolution MR imaging we demonstrate that the first plantar plate is a dynamic capsuloligamentous complex. Quantitative MR of important structures of the first MTP joint may allow for earlier diagnosis, stage of injury, and therapeutic monitoring.

Vladimir Juras^1,2, Vladimir Mlynarik¹, Pavol Szomolanyi^1,2, Marek Chmelik¹, and Siegfried Trattnig^1
1High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, ²Department of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia

The results of this study provide a guide how to perform the bi-exponential T2* fitting in Achilles tendon. Besides the usual conditions used in bi-exponential fitting (such as SNR and R2 threshold), other conditions such as limits for the ratio of T2*s and T2*l obtained by fitting should also be considered for calculating reasonable T2* values. The results of this study can be extended also to other tissues (menisci, ligaments, nerves) and is method independent (works with radial 2D and 3D-UTE, AWSOS, SPRITE).

Eric Y Chang^1,2, Paul M DiCamillo², Sheronda Statum², Christine B Chung^1,2, Nikolaus M Szeverenyi², and Graeme M Bydder^2
1Department of Radiology, VA San Diego Healthcare System, San Diego, CA, United States, ²Department of Radiology, University of California, San Diego Medical Center, San Diego, CA, United States

This study was performed to visualize the entheses of the foot at 3T and 11.7T utilizing 2D and 3D images. The contrast and quality of the MR images obtained have never been shown before. These include the Achilles tendon, tibialis posterior tendon at the level of the medial malleolus and at the navicular insertion, central slip of the extensor tendon of the toes, collateral ligaments, and plantar plate. We also demonstrate collagen fiber structure which has not previously been described, including perpendicular fibers at functional entheses.

Chao-Ying Wang¹, Ping-Huei Tsai^2,3, Shih-Wei Chiang^1,4, Yi-Chih Hsu¹, Herng-Sheng Lee⁵, Yue-Cune Chang⁶, Ming-Chung Chou⁷, Ming-Huang Lin⁸, Chien-Yuan Lin⁸, Hsiao-Wen Chung⁴, and Guo-Shu Huang^1
1Department of Radiology, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan, ²Imaging Research Center, Taipei Medical University, Taipei, Taiwan, ³Department of Medical imaging, Taipei Medical University, Taipei, Taiwan, ⁴Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, ⁵Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ⁶Department of Mathematics, Tamkang University, Taipei, Taiwan, ⁷Department of Medical Imaging and Radiological Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan, ⁸Institute of Biomedical Sciences, Academic Sinica, Taipei, Taiwan

In this study we use MR T2* value to compare local changes in signal intensity over time in Hoffa¡¦s fat pad in anterior cruciate ligament transection (ACLX) rats. We have applied these techniques to investigate at different time points including week 0, 4, 13, 18 in three groups (control, ACLX-shame and ACLX) after surgery. After MR imaging at week 18, we scarified the rat and undergone histological analysis. We conclude that in our study of Hoffa¡¦s fat pad, MR T2* measurement can be an useful biomarker to provide early physiological information in knee instability disease.

Ping-Huei Tsai^1,2, Hsiao-Wen Chung³, Teng-Yi Huang⁴, Wing P Chan⁵, Cheng-Yu Chen^2,6, and Fong Y Tsai^1
1Imaging Research Center, Taipei Medical University, Taipei, Taiwan, ²Department of Medical Imaging, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan, ³Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, ⁴Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, ⁵Department of Radiology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan, ⁶Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan

Meniscus plays a critical role to maintain mechanical function of knee and is related to initiation of osteoarthritis. Although several papers have demonstrated the feasibility of using UTE sequence to target the short T2 component and derive the corresponding T2* map, it is not easy to assess the in vivo human meniscus T2* value with high resolution due to a relatively long scan time. The purpose of this study is using dual echo radial imaging sequence conjugated with undersampled projection reconstruction for accelerated meniscus T2* measurements. The present finding indicated that the use of the proposed method is able to obtain a reliable T2* value of the in vivo human meniscus.

Beate Blutsch¹, David Stelzeneder², Silke Aldrian¹, Christian Albrecht¹, Patrick Platzer¹, Stefan Hajdu¹, and Siegfried Trattnig^3
1Department of Trauma Surgery, Medical University of Vienna, Vienna, Austria, Austria, ²Department of Orthopaedics, Medical University of Vienna, Vienna, Austria, Austria, ³Department of Radiology, Centre of Excellence “High Field MR”, Medical University of Vienna, Vienna, Austria, Austria

Meniscal tears are commun injuries of the knee joint. The preservation of the meniscus is getting more and more important because of the rising number of osteoarthritis after (partial) meniscectomy. In our study patients with a meniscal tear that was treated operatively with meniscus refixation were examined with a 7T MRI, a clinical examination and an interview six and twelve months postoperatively. The Meniscal Repair Assessment Score (MERAS), a new MRI scoring tool for evaluation of the sutured meniscus was created, indicating good radiological outcome. Meniscal refixation offers satisfying clinical and imaging results.

Michael Carl¹, Jiang Du², Nikolaus M Szeverenyi², Sheronda Statum², Christine B Chung², and Graeme M Bydder^2
1Global MR Applications & Workflow, General Electric, San Diego, CA, United States, ²University of California, San Diego, CA, United States

The root ligaments of the meniscus have an essential role in maintaining the mechanical integrity of the knee. It is possible to demonstrate tendons and ligaments as high signal structures using 3D UTE subtraction images in which short T2 tissues are highlighted. In order assess whether this was feasible and whether contrast administration would be detectable over time we studied a volunteer before and after injection of gadolinium. The root ligaments can be readily demonstrated and can be identified by their cross section appearance, internal structure and location.

Huan-Chu Lo¹, Sheng-Tsai Hung¹, Duen-Pang Kuo¹, and Hung-Maan Lee^1
1Armed Forces Taoyuan General Hospital, Taoyuan, Taiwan, Taiwan

Partial-thickness rotator cuff tear is usually depicted by a focal hyperintensity within a tear shown on fat-suppression T2 weighted magnetic resonance imaging (FS-T2WI). However, the hyperintensity is not always easily detected by FS-T2WI. To investigate the diagnostic performance of diffusion-weighted magnetic resonance imaging (DWI) for assessment of partial-thickness rotator cuff tears by means of lesion to muscle signal intensity ratios (L/M SIR ) as an alternative method.

Vladimir Juras^1,2, Pavol Szomolanyi^1,2, Benedikt Hager¹, Marek Chmelik¹, Stefan Zbyn¹, Jan Vosshenrich¹, and Siegfried Trattnig^1
1High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, ²Department of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia

This study showed that sodium MRI is sensitive enough to visualize macromolecular alterations which are present after ciprofloxacin treatment. Interestingly, gagCEST does not demonstrate this ability, although the p-value for BULK was only slightly above 0.05. T2* reflects mostly the water and collagen interplay, therefore, no change was observed. In conclusion, sodium MRI was proven to be a potential marker for Achilles tendinopathy after ciprofloxacin treatment.

Pavol Szomolanyi¹, Andreas Teuschl^2,3, Martin Brix^1,4, Joachim Friske¹, Vladimir Juras¹, Xeni Deligianni⁵, Oliver Bieri⁵, Thomas Nau⁶, Heinz Redl^3,6, and Siegfried Trattnig^1
1Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, High Field MR Centre, Vienna, Vienna, Austria, ²City of Vienna Competence Team Tissue Engineering Bioreactors, University of Applied Sciences Technikum Wien, Vienna, Austria, ³The Austrian Cluster for Tissue Regeneration, Vienna, Austria,⁴Department of Orthopaedics, Medical University of Vienna, Vienna, Austria, ⁵Department of Radiology, University of Basel Hospital, Division of Radiological Physics, Basel, Switzerland, ⁶Ludwig Boltzmann Institute for clinical and experimental Traumatology, Vienna, Austria

Most promising materials for ACL reconstruction are based on silk fibroin as scaffold material. Surprisingly, there is still a lack of knowledge on the integration of silk fibroin scaffolds into bone. Thus, the goal of this study was to evaluate the integration of silk fibroin into the bone by using MRI UTE sequence. MR analysis demonstrated that after 6 months the silk scaffolds were surrounded by soft tissue that further developed to the tight osteointegration. Our study show that UTE is the technique of choice for MR imaging of the very short T2* tissues.

Taiki Nozaki^1,2, Junko Ochi², Chiharu Osakabe², Atsushi Tasaki³, Yasuhito Kaneko¹, and Hiroshi Yoshioka^1
1Radiological Sciences, University of California, Irvine, Orange, California, United States, ²Radiology, St.Luke's International Hospital, Chuo-ku, Tokyo, Japan, ³Orthopedic Surgery, St.Luke's International Hospital, Tokyo, Japan

In preoperative assessment of rotator cuff tear, it is very important to evaluate the degree of fatty degeneration of the rotator cuff muscles for deciding the indication of operation, and predicting the clinical functional outcome. However, in clinical practice qualitative method is widely used for evaluation of fatty degeneration. The objective of this study is to prospectively quantify fatty degeneration of the supraspinatus muscle by using 2-point Dixon technique at 3.0-T MRI, and to evaluate the correlation with severity of rotator cuff tears.

Monica Tafur¹, Kenyu Iwasaki¹, Sheronda Statum¹, Christine B. Chung^2,3, Nikolaus M. Szeverenyi¹, and Graeme M. Bydder^1
1Radiology, University of California, San Diego, San Diego, California, United States, ²Radiology, VA San Diego Healthcare System, San Diego, California, United States,³Radiology, Univerisity of California, San Diego, San Diego, California, United States

In this study, we have obtained high resolution, high field (11.7 Tesla) Magnetic Resonance (MR) images of the pulleys of the flexor tendons of cadaveric toe specimens. Although the anatomy of the pulley system has been described in one previous article, there have been no previous MRI descriptions of the pulley system of the toes published in the imaging literature. Understanding of toe pulley anatomy is likely to be of benefit in diagnosing tenosynovitis and recognizing the effects of trauma. Detailed anatomy of the pulley system of the flexor tendons allows similarities and differences between the pulley system in the foot and that in the hand to be identified. The A5 pulley, which has previously been described only in the 2nd to 5th fingers, was also present in the lesser toes. The MR visualization of the pulleys included features not seen or reported in descriptions of the finger pulleys such as the internal structure and magic angle effects. Validation was performed by direct inspection of anatomic specimens.

Sarah L Pownder¹, Parina Shah¹, Michael Schaer², Richard Ma³, Xiang-Hua Deng², Matthew F Koff¹, Scott A Rodeo^2,4, and Hollis G Potter^1
1MRI, Hospital for Special Surgery, New York, NY, United States, ²Laboratory for Soft Tissue Research, Hospital for Special Surgery, NY, United States, ³Missouri Orthopaedic Institute, University of Missouri, Columbia, MO, United States, ⁴Sports Medicine and Shoulder Service, Hospital for Special Surgery, NY, United States

Preclinical orthopaedic studies of anterior cruciate ligament reconstruction (ACLR) may allow free cage movement of animals post-operatively. The associated joint loading due to ambulation is a confounding variable that may affect graft healing. Loads which disrupt tendon collagen fibers and alter UTE T2* values have not been established. We developed a low-load rabbit ACLR model by combining unique tunnel position and pretensioning . Similar tendon T2* values were found between mobilized and immobilized rabbits following ACLR. These data demonstrate conditions in which strain is insufficient to alter T2* values, obviating the need for immobilization in this model.

Elmar Laistler^1,2, Andre Kuehne^1,2, Sigrun Goluch^1,2, Barbara Dymerska², Jürgen Sieg^1,2, and Ewald Moser^1,2
1Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria, ²MR Center of Excellence, Medical University of Vienna, Vienna, Austria

A highly sensitive dedicated RF coil for finger micro-imaging at 7 T is presented, suited to investigate tendons and other anatomical structures in the human finger in vivo.

Jihyun Lee¹ and Yang Xia^1
1Physics and Center for Biomedical Research, Oakland University, Rochester, Michigan, United States

This study aims to quantify the loading-modified topographical and zonal T1 in articular cartilage in early experimental canine OA using µMRI at the 17.6µm resolution and when the tissue was soaked with the Gd contrast agent. Both OA and mechanical compression were found to be able to alter the T1 relaxation time of articular cartilage at each sub-tissue zone and topographically, which provide a better understanding of the MRI properties of cartilage during joint loading. This result could help to design effective protocols in clinical MRI to better detect and manage the articular diseases.

Eveliina Lammentausta¹, Arttu Peuna¹, Pavol Szomolanyi², Stefan Zbyn², Siegfried Trattnig², and Miika T Nieminen^1,3
1Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Oulu, Finland, ²Vienna Medical University, Vienna, Austria, ³Department of Radiology, University of Oulu, Oulu, Finland

We present a tool for three-dimensional MR image co-registration based on demon algorithm. According to preliminary results, it is possible to reliably co-register images obtained from the same subject at different imaging sessions acquired using different scanners at different field strengths and even multinuclear studies.

Feliks Kogan¹, Jarrett Rosenberg¹, Emily J McWalter¹, Daniel Park², Stephen Matzat¹, Kevin Prekins², Catherine Tran¹, Merideth Taylor², Bragi Sveinsson¹, Rex Newbould², Uche Monu¹, Haonan Wang², Neal K Bangerter², and Garry E Gold^1
1Radiology, Stanford University, Stanford, CA, United States, ²Electrical & Computer Engineering, Brigham Young University, Provo, UT, United States

In this study, we assessed the repeatability and reproducibility of quantitative MRI measurements of cartilage morphometry and tissue parameters intra-site and between sites and manufacturers. Quantitative measurements of tissue morphometry, T2, and sodium concentration were repeatable within a given site as determined by a high concordance correlation coefficient. Between sites with different manufacturers, correlation was high for morphologic imaging. Sodium concentration measurements showed a correctable bias while use of different acquisition sequences on different platforms for T2 measurements showed errors that are not easily correctable.

Emily J McWalter¹, Bragi Sveinsson¹, Edwin H Oei^1,2, William H Robinson¹, Mark C Genovese¹, Garry E Gold¹, and Brian A Hargreaves^1
1Stanford University, Stanford, CA, United States, ²Erasmus MC, Netherlands

Synovitis is frequently observed osteoarthritis and is characterized by synovial thickening and joint effusion. Contrast enhanced T1-weighted imaging is the current gold standard for detecting synovitis; however, introducing contrast enhanced images at the end of a knee protocol increases time, cost and risk to patients. We propose double echo in the steady state (DESS) imaging for synovitis detection without the need for administration of an intravenous contrast agent and demonstrate that with a linear combination of the DESS echoes, improved contrast between the synovial membrane and fluid can be achieved.

Stephanie Hou¹, Lorenzo Nardo¹, Ursula Heilmeier¹, Sonia Lee¹, John Lynch¹, Chuck McCulloch¹, Gabby Joseph¹, and Thomas Link^1
1UCSF, San Francisco, CA, United States

This longitudinal study identified morphological MRI findings correlated with development of new pain over a period of 4 years in the knees of subjects at risk for osteoarthritis. The following findings were significantly associated with pain: baseline medial tibial cartilage pathology, baseline medial meniscus body pathology, incident effusion, and progressive patella cartilage pathology. Trends suggested an association of the following findings with pain: baseline medial tibia bone marrow edema pattern, medial femoral condyle bone marrow edema pattern at 4 years, and anterior medial meniscus pathology at 4 years. These associations may help radiologists to better guide clinical treatment.

Giulia Di Pietro^1,2, Eleonora Piccirilli³, Monica Celi³, Umberto Tarantino³, and Silvia Capuani^2,4
1IIT@Sapienza, Physics Department, “Sapienza” University, Rome, Rome, Italy, ²Physics Department, “Sapienza” University, Rome, Rome, Italy, ³Department of Orthopaedics and Traumatology, University of Rome “Tor Vergata”, Rome, Rome, Italy, ⁴CNR IPCF UOS Roma, Physics Department, “Sapienza” University, Rome, Italy

In this in vitro study performed at 9.4T, the internal magnetic field gradient (IMFG) was used to discriminate between femoral neck samples extracted from osteoporotic (OP) and osteoarthritic (OA) patients. IMFG values were lower in OP compared to OA suggesting a higher trabecular density in OA specimens. IMFG values were lower in the metaphysis compared to subchondral section in both OP and OA samples. These results are in agreement with the packing of subchondral bone occurring in OA. In subchondral section of OP specimens the higher IMFG values are due to the marrow fat content increase

Ning Zhang¹, Jeremy F Magland¹, Chamith S Rajapakse¹, Hee Kwon Song¹, and Felix W Wehrli^1
1University of Pennsylvania, Philadelphia, PA, United States

Subject motion degrades image quality. Intra-scan subject motion can further mask detectability of treatment effects in time-series studies. Here we present a registration-based technique designed to retrospectively correct for rigid-body intra-scan subject motion. Results from in-vivo micro-MR images of the distal radius show significant improvements in both image quality and serial reproducibility on image-derived trabecular bone micro-structure and biomechanics compared to the navigator-based and autofocusing techniques.

Habib Al saleh¹, Richard Kijowski², and Walter F Block^1,3
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

For a single row, phased array knee coil, the azimuthal coil arrangement reduces sensitivity in the transverse plane and hence the PILS effect reduces the number of radial lines required to fully sample an axial slice. However, accelerating volumetric scans is limited as the coil arrangement provides no variation in sensitivity in the S/I dimension . We compare the impact of a multiple row arrangement against a single coil design in 3D radial joint imaging through the following 2 studies: 1) varying the undersampling factor for a given resolution while maintaining the same stochastic noise level and 2) a comparison of image quality with challenging 0.33 mm isotropic resolution scan in 8 minutes. Preliminary results demonstrate significantly higher image through use of a multiple row coil with S/I sensitivity.

Martin Brix^1,2, David Stelzeneder¹, Stephan Domayer³, Stefan Nehrer⁴, Thomas Luksch⁴, Götz Welsch⁵, Martina Schinhan¹, Catharina Chiari¹, Sebastian Apprich¹, Reinhard Windhager¹, and Siegfried Trattnig^2
1Department of Orthopaedics, Medical University of Vienna, Vienna, Austria, ²High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria, ³Sonderkrankenanstalt Zicksee, Austria, ⁴Danube University Krems, Krems, Austria, ⁵Department for Trauma Surgery, University Hospital Erlangen, Erlangen, Germany

The aim of our study was to assess the repair tissue structure after a matrix associated autologous chondrocyte transplantation technique using biochemical MRI. Fourteen knees of 14 patients were assessed in that cross-sectional study at a mean follow up of 2.0 ± 0.9 years. The results demonstrated a zonal variation not only in T2-maps, but also in dGEMRIC images. This suggests a gradual increase in proteoglycan content of repair tissue from the superficial to the deep layer.

Susanna Ahola¹, Ville-Veikko Telkki¹, Eveliina Lammentausta², Jessica M. Rosenholm³, Elli-Noora Salo², Gamzegul M. Behrouz¹, Roberto Blanco Sequeiros^2,4, and Miika T. Nieminen^2,4
1Department of Physics, University of Oulu, Oulu, Oulu, Finland, ²Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland, ³Centre of Functional Materials, Laboratory of Physical Chemistry, Åbo Akademi University, Turku, Finland, ⁴Department of Radiology, University of Oulu, Oulu, Finland

Feasibility of new manganese oxide nanoparticles (MnOx) as contrast agent for articular cartilage was investigated in vitro. The diffusion of MnOx into articular cartilage was followed by measuring T1 maps for 24 hours at repeated intervals after immersing osteochondral samples into the MnOx and, subsequently, after immersing the sample in saline solution for another 24 hours. For comparison, the post-contrast part of the study was repeated with Gd-DTPA solution. MnOx diffused rapidly into cartilage and appears to permanently bind in high concentration to a region near the calcified zone. Thus MnOx is a potential biomarker for highlighting the cartilage-bone interface.

Mustapha Bouhrara¹, David A Reiter¹, Hasan Celik¹, Jean-Marie Bonny², Vanessa Lukas¹, Kenneth W Fishbein¹, and Richard G Spencer^1
1NIA, NIH, Baltimore, Maryland, United States, ²QuaPa, INRA, Saint Genès Champanelle, France

The noise distribution of magnitude MR data obtained through quadrature detection exhibits a Rician, rather than Gaussian, probability distribution. Previous work has assessed the importance of thisin fitting monoexponential decay curves. Recently, there has been a renewed interest in tissue compartmentation studies through use of multiexponential analysis. Accordingly, we extend the analysis of the effect of Rician noise to the much more complex problem of biexponential decay through use of Monte Carlo simulations, and phantom and cartilage explant studies. We find that explicit incorporation of the Rician statistical characteristics of the signal leads to markedly improved results.

Stefan Zbyn¹, Stephan E. R. Domayer², Martin O. Brix^1,2, Sebastian Apprich^1,2, Jochen G. Hofstaetter², Sonja M. Walzer², Vladimir Mlynarik¹, Vladimir Juras¹, Reinhard Windhager², and Siegfried Trattnig^1
1High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University Vienna, Vienna, Austria, ²Department of Orthopedics, Medical University Vienna, Vienna, Austria

To our best knowledge, this is the first report on employing sodium (23Na) MRI for the evaluation of native cartilage and cartilage repair tissue in the ankle joint. Data from cadaver ankle samples demonstrate that 23Na MRI is sensitive to changes in the GAG content of thin tibial and talar cartilage in the ankle. Observed 23Na concentrations in the volunteers are in agreement with previous findings, and demonstrate feasibility of the quantification of 23Na concentration in cartilage of the ankle joint at 7T. 23Na MRI may be useful for the noninvasive evaluation of the repair tissue in the ankle joint.

Victor Casula¹, Simo Saarakkala², Elli-Noora Salo², Jari Rautiainen¹, Virpi Tiitu³, Olli-Matti Aho⁴, Petri Lehenkari⁴, Jutta Ellermann⁵, Mikko J. Nissi⁵, and Miika T. Nieminen^1
1Department of Radiology, University of Oulu, Oulu, Oulu, Finland, ²Department of Diagnostic Radiology, University of Oulu, Oulu, Oulu, Finland, ³Institute of Biomedicine, Anatomy, University of Eastern Finland, Kuopio, Kuopio, Finland, ⁴Department of Anatomy and Cell Biology, University of Oulu, Oulu, Oulu, Finland, ⁵Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, United States

In this study k-means clustering algorithm was applied to multiparametric MRI data to classify normal and degenerated articular cartilage. Various MRI parameters were assessed at 9.4 T in intact and degraded human cartilage samples and enzymatically degraded bovine cartilage samples. OARSI grading was used as reference for human cartilage. High sensitivity and specificity were achieved using several combinations of two parameters. The best classification involved rotating-frame techniques. Similar results were obtained with combinations of three parameters with no improvements in terms of specificity and sensitivity.

Joshua Michael Farber¹, Saara Totterman², Jose Tamez-Pena³, Eric Brandser⁴, Edward Schreyer², and Bruce Holladay^5
1Radiology, Qmetrics Technologies., Cincinnati, Ohio, United States, ²Radiology, Qmetrics, Rochester, NY, United States, ³Bio Sciences, Tec De Monterry, Monterry, Monterry, Mexico, ⁴Radiology, Radiology Ass. of N KY, KY, United States, ⁵Orthopaedic surgey, Commonwealth Orthopaedic Centers, Edgewood, KY, United States

Allograft procedures for knee articular cartilage defect repair are becoming common, almost routine. This paper examines the appearance of successful and failed grafts to study the process of graft incorporation and to develop imaging biomarkers for successful graft incorporation.

Yihang Zhou¹, Valentina Pedoia², Julien Rivoire², Yanhua Wang¹, Dong Liang³, Xiaojuan Li², and Leslie Ying^1
1Department of Biomedical Engineering, Department of Electrical Engineering, The State University of New York at Buffalo, Buffalo, NY, United States, ²Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, United States, ³Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China

In this study, the feasibility of combining compressed sensing (CS) with parallel MRI (pMRI) in accelerating the T1ρ cartilage imaging is investigated. K-t ISD with locally-adapted thresholding, named k-t LISD, combined with JSESNE is used to reconstruct the image sequence from undersampled data in (k, t) space. The reconstruction process alternates iteratively between k-t LISD for reconstruction of the image sequence and JSENSE for sensitivity estimation. Result on in-vivo human knee experiment shows the T1ρ quantification from the accelerated acquisition using the proposed method is consistent with that from full acquisition in all cartilage compartments.

Ryan Nazareth¹, Peter Cashman², Pauline Parlier², Annie Papadaki¹, Lesley Honeyfield¹, Keshthra Satchithananda¹, Donald McRobbie¹, and Fiona Watt^3
1Imperial College Healthcare NHS Trust, London, United Kingdom, ²Imperial College London, London, United Kingdom, ³Kennedy Institute of Rheumatology, Oxford, United Kingdom

Monitoring cartilage thickness change is desirable in individuals with knee injuries who are at high risk of early osteoarthritis. The segmentation of cartilage from knee MR images is greatly complicated by the presence of metal artefacts. Here, we present a semi-automated in-house software which can accurately segment cartilage boundaries and estimate cartilage thickness, provided the metal artefact is only contained with the bone. This software offered the same level of accuracy and precision compared to manual tools used by radiographers but with a substantial reduction in time, robustness to changes in display contrast and brightness, and excellent inter-observer agreement.

Shih-Wei Chiang^1,2, Hsiao-Wen Chung¹, Chao-Ying Wang², Yi-Chih Hsu², and Guo-Shu Huang^2
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

Chronic kidney disease (CKD) is associated with a wide range of disorders of mineral and bone metabolism. Understanding the pathophysiology in mineral metabolism and bone diseases is very important, as recent evidence has suggested the concept of bone-vascular axis in CKD. Our preliminary findings suggest that CKD-related T2 changes in the medial meniscus may precede alterations in other cartilage regions.

Joachim Hermann Xaver Schrauth^1,2, Gunthard Lykowsky^1,2, Daniel Weber¹, Jakob Kreutner^1,2, Kathrin Hemberger^1,2, Lars Rackwitz³, Ulrich Nöth³, Peter Jakob^1,2, and Daniel Haddad^1
1Molecular & Cellular MRI, MRB Research Center for Magnetic Resonance Bavaria, Wuerzburg, Bavaria, Germany, ²Experimental Physics 5 (Biophysics), University Wuerzburg, Wuerzburg, Bavaria, Germany, ³König-Ludwig-Haus, Orthopädische Universitätsklinik Würzburg, Wuerzburg, Bavaria, Germany

The aim of this study was to compare Sodium, T1ρ and dGEMRIC measurements for the characterization of the goat cartilage after inducing Osteoarthritis in a control and cell based treated group. The results of all methods show expected behavior over the course of 16 weeks after the defect, though T1ρ seems to be most sensitive to early changes in the cartilage. Moreover we found a very strong correlation between the both known dGEMRIC indices and moderate correlations between Sodium & dGEMRIC(1), dGEMRIC(1) & T1ρ and dGEMRIC(2) & T1ρ.

Mohammad Haris^1,2, Anup Singh¹, Kejia Cai^1,3, J. Bruce Kneeland⁴, Fotios Tjoumakaris⁵, Hari Hariharan¹, and Ravinder Reddy^1
1CMROI, Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States, ²Research Branch, Sidra Medical and Research Center, Doha, Qatar, ³CMRR 3T Research Program, University of Illinois at Chicago, Chicago, IL, United States, ⁴Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States, ⁵Sports Medicine at Rothman institute, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, United States

The concept of viscosupplementation has gained widespread acceptance as a new treatment for the management of osteoarthritis (OA) of the knee. Here, we evaluate the chemical-exchange-saturation-transfer effect from the two popular viscosupplementations (Synvisc and Orthovisc) by exploiting the exchangeable hydroxyl groups present on these molecules at 7T human scanner. Both viscosupplementations showed a strong CEST effect at ~1 ppm. Furthermore, using the CEST technique it may possible to map the fate of the injected viscosupplementation in knee joints of OA patients over time as well as their effect on knee cartilage GAG concentration.

Afsaneh Amirabadi¹, Adrian Crawley², Carina Man¹, Tammy Rayner¹, Ruth Weiss¹, Joseph Fisher^2,3, and Andrea Doria^1,4
1The Hospital for Sick Children, Toronto, ON, Canada, ²The University Health Network, ON, Canada, ³Thornhill Research Inc., ON, Canada, ⁴University of Toronto, ON, Canada

Juvenile idiopathic arthritis is the most frequent chronic rheumatologic disease of childhood. Early diagnosis may improve therapy efficacy and decrease adverse outcomes. In the acute arthritis increased metabolic demand and the inadequate oxygen delivery through the inflamed synovium result in hypoxia. In this study 3T BOLD MRI was used to obtain functional information of the periarticular tissue reactivity in response to local hypoxia which is directly relevant to the pathogenesis of arthritis. End-tidal gas concentrations were manipulated using a model-based prospective targeting device during BOLD MRI. The results showed non statistically significant percent signal change difference between inflammatory and healthy tissue.

Uyen Hoang¹ and Usha Sinha^2
1Bio-informatics, SDSU, San Diego, CA, United States, ²Physics, SDSU, San Diego, CA, United States

Osteoarthritis causes among other changes, loss in cartilage volume which increases as the disease progresses. Cartilage loss with disease progression is small and localized to sub regions of the cartilage, making detection challenging. We report the deformation (Jacobian) maps of femoral cartilage in a longitudinal study (baseline and 12 mo.) to identify subtle and localized interval changes. Subject data from the Osteoarthritis Initiative which had segmented cartilage in longitudinal studies was used. The Jacobian maps allow visualization of small and localized changes and could potentially enable population based studies on cartilage morphometry.

Yang Xia¹ and Nian Wang^1
1Physics and Center for Biomedical Research, Oakland University, Rochester, Michigan, United States

To investigate the molecular origin that darkens the deep-region of articular cartilage when the tissue is compressed and oriented at the magic angle, T2 and T1ρ experiments were used to study native and degraded cartilage. The glycosaminoglycan (GAG) concentrations in the specimens were quantified by both sodium ICP-OES and T1-Gd methods. The GAG concentration was found to play the key role in the formation of this low-intensity layer in the deep-region of the compressed cartilage. A schematic model has been formulated to explain the structural differences in the deformation of the collagen matrix between native and degraded tissues.

Dingxin Wang^1,2, Abraham Padua Jr³, Jutta Ellermann², Xiufeng Li², Kamil Ugurbil², and Vibhas Deshpande^4
1Siemens Medical Solutions USA, Inc., Minneapolis, MN, United States, ²Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States,³Siemens Medical Solutions USA, Inc., Houston, TX, United States, ⁴Siemens Medical Solutions USA, Inc., Austin, TX, United States

Our study demonstrates the clinical application of multiband slice accelerated TSE combined with in-plane parallel imaging for high resolution knee imaging at 3T. Multiband slice acceleration improves the acquisition efficiency of TSE. A total of 4 times acceleration can be achieved using an 8-channel knee coil.

Wen Ling¹, Rob Hartman², Tao Jin¹, Nam Vo², Gwendolyn Sowa², James Kang², Michel Modo¹, and Kyongtae Ty Bae^1
1Dept. of Radiology, UPMC, Pittsburgh, PA, United States, ²Dept. of Orthopaedic Surgery, UPMC, Pittsburgh, PA, United States

The applicability of CEST on intervertebral disc is highly dependent on the knowledge of MT asymmetry. The MT asymmetry of disc and cartilage was evaluated under spin-lock condition with different pair of RF power / duration in rabbit discs and bovine cartilage.

Thomas Kaulisch¹, Laura Corradini², and Detlef Stiller^3
1Target Discovery Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Baden-Württemberg, Germany, ²CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Baden-Württemberg, Germany, ³Target Discovery Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Baden-Württemberg, Germany

The Mono-Iodoacetate (MIA) model is an attractive tool for testing novel compounds at different stages of progressive osteoarthritis (OA) development. We characterize the inflammatory component by means of MRI-based volumetry and DCE-MRI and demonstrate treatment effects when using Celecoxib.

Hatice T SANAL¹, Sertan GEZGIN¹, and Cem TAYFUN^2
1Radiology, Gulhane Military Medical Academy, ANKARA, Kecioren, Turkey, ²Radiology, Gulhane Military Medical Academy (R), ANKARA, Kecioren, Turkey

Several parameters on T2* time-intensity curves, obtained from lower extremity muscles of patients having arterial occlusive disease and healthy volunteers, have been evaluated through BOLD MR imaging. Time to peak (TTP) value longer than 40 sec suggest insufficient blood sources to the muscle with a sensitivity and specificity of % 83.3, % 92.3, respectively. Interestingly, in one volunteer with normal artrerial system but with venous insufficency, TTP was longer than expected. TTP value with a threshold of 40 sec, can exclude stenosis with a great sensitivity, unless venous insufficiency is exluded.

*Valeria Ricotti¹, *Matthew RB Evans², Christopher DJ Sinclair², Jasper M Morrow², Jordan W Butler¹, Robert L Janiczek³, Michael G Hanna², Paul M Matthews³, Tarek A Yousry², Francesco Muntoni^1,2, and John S Thornton^2
1Dubowitz Neuromuscular Centre, UCL Institute of Child Health and Great Ormond Street Hospital, London, United Kingdom, ²MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, United Kingdom, ³GlaxoSmithKline, London, United Kingdom

Assessing dystrophin restoration in the muscle of DMD patients undergoing experimental gene therapies requires an invasive muscle biopsy. MRI may provide a non-invasive alternative to evaluate response to therapy; however the natural course of DMD muscle changes needs to be established. Examination of the upper limb will allow recruitment of ambulant and non-ambulant patients in clinical trials. Eight non-ambulant DMD patients and 10 healthy controls underwent 3-point Dixon fat-fraction forearm imaging revealing significantly higher fat fraction and muscle atrophy in DMD. Additionally, duration of non-ambulation and wrist extension myometry correlated with MRI indices. MRI is a potential biomarker for evaluating DMD progression.

Sunil K. Valaparla^1,2, Erika M. Ripley², Goldie R. E. Boone², Timothy Q. Duong¹, and Geoffrey D. Clarke^1,2
1Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States, ²Radiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States

1H-MRS and two-point Dixon MRI provide reliable fat fraction, correlating well with tissue biopsies. This study compared fat fraction in human vastus lateralis (VL) using Dixon MRI and long TE 1H-MRS at 3T. Fat fraction exhibited considerable inter-individual variability for 1H-MRS FF (%) = 3.61 ± 2.25 (range: 1.34 – 7.23) and Dixon MRI FF (%) = 3.11 ± 1.17 (range: 1.77 – 5.60). Linear regression analysis showed good correlation (r = 0.8746) between FF (%) from two methods. These methods can provide insight on muscular fat interference with insulin signaling in diabetes and give a reliable basis for longitudinal clinical studies.

Patrick Hiepe¹, Martin Krämer¹, Alexander Gussew¹, and Jürgen R. Reichenbach^1
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital, Jena, Germany

The aim of the present study was to apply a radial multi-echo gradient-echo (GRE) sequence during dynamic exercising for continuous quantitation of the effective transverse relaxation time constant (T2*) enabled by the increased robustness of radial trajectories against motion artefacts. Load-induced T2*-changes were determined based on mono-exponential and multi-component signal fitting of data obtained in a human calf during plantar flexion.

Barbara Janssen¹, Nicoline Voet², Alexander Geurts², George Padberg³, Baziel van Engelen³, and Arend Heerschap^1
1Radiology, Radboud University Medical Center, Nijmegen, Gelderland, Netherlands, ²Rehabilitation, Radboud Univeristy Medical Center, Nijmegen, Gelderland, Netherlands,³Neurology, Radboud Univeristy Medical Center, Nijmegen, Gelderland, Netherlands

DUX4 expression by a genetic abnormality is believed to cause fascioscapulohumeral muscular dystrophy (FSHD), however the mechanism leading to muscle pathology remains unknown. We present MRI findings that validate a dynamic model with DUX4 initiation and propagation of a transcriptional cascade in myofibers. The majority of muscles in patients are either normal or highly fat infiltrated, indicating an abrupt transition to a diseased state, which agrees with clinical observation. As predicted by the model we identified a minor muscle fraction with intermediate fatty infiltration, which occurs as a longitudinal muscular gradient and shows fast progression of the fatty infiltration.

Amanda K. W. Buck¹, Zhaohua Ding^1,2, Christopher P. Elder¹, Theodore F. Towse^1,3, and Bruce M. Damon^1
1Vanderbilt University Institute of Imaging Science, Nashville, TN, United States, ²Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, TN, United States, ³Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, TN, United States

DT-MRI-based fiber tractography allows non-invasive estimation of three-dimensional muscle architecture; however, DT-MRI in the leg suffers from low SNR, which can introduce error in the estimation of diffusion tensor eigenvectors used for tract propogation. This study assesses the effect of anisotropic smoothing on fiber tracking measures in the medial gastrocnemius muscle in healthy subjects.

Jules L. Nelissen¹, Willeke A. Traa², Larry A. de Graaf¹, Kevin M. Moerman³, Aart J. Nederveen³, Cees W. Oomens², Klaas Nicolay¹, and Gustav J. Strijkers^1
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ²Soft Tissue Biomechanics and Engineering, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ³Department of Radiology, Amsterdam Academic Medical Center, Amsterdam, Netherlands

A novel MR compatible indentor was designed, build and tested to provide new insights in the etiology of pressure ulcer related deep tissue injury. The design allows flexible positioning of the indentor and was tested by applying 2h sustained mechanical loading to the tibialis anterior (TA) muscle of rat inside a MR scanner. T2 weighted scans, T2 maps and angiography were used to assess skeletal muscle injury and physiological changes. Hyperenhancement due to the formation of edema, resembling the structure of vasculature in the TA muscle is observed in strong T2weighted scans. T2 maps show the similar capillary bed structure.

Yeon Hwa Yoo¹, Yaena Kim¹, Young Han Lee², Mun Young Paek³, Sungjun Kim¹, Tae-Sub Chung¹, Choon-Sik Yoon¹, Ho-Taek Song², and Jin-Suck Suh^2
1Radiology, Gangnam Severance Hospital, Yonsei University College of Medicine., Seoul, Korea, ²Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea, ³Siemens Ltd. Seoul, Seoul, Korea

Fat-signal fraction has been quantified for phantom and variable tissues using variable sequences based on Dixon techniques. Recently, fat-signal fraction mapping using multi-echo Dixon techniques have been developed for further improvement of accuracy. However, there has been no consensus whether T2*-corrected multi-echo Dixon technique can more accurately measure fat-signal fraction in skeletal muscle as compared with the 2-echo and 3-echo techniques particularly when T2*-correction is added, albeit being expected so. This study is the first one that T2*-corrected multi-echo Dixon technique is superior to the sequences previously tested for the purpose.

Chenfei Ye¹, James F. Griffith², Heather T. Ma¹, David K. Yeung², Alvin F. Li², and Xu Xing^1
1Department of Electronic and Information Engineering, Harbin Institute of Technology Shenzhen Graduate School, Shenzhen, Guangdong, China, ²Department of Imaging and Interventional Radiology, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong

This study examined the BOLD effect on calf muscles in elderly subjects to investigate the oxygenation characteristics in different calf muscle groups for the elderly females. Temporary vascular occlusion was induced with air-cuff compression of the thigh and BOLD-MRI data curve was fitted to derive quantitative parameters. The BOLD signal in soleus muscle showed the lowest minimum ischemic value during ischemia and the steepest slope during hyperemia. As soleus muscle is mainly composed by slow-twitch oxidative muscle fibers, current results may be due to a higher vascular bed density and better endothelial function in such muscle.

Noura Azzabou¹, Jean-Yves Hogrel², Yoann Barnouin², and Pierre G Carlier^1
1AIM-CEA Institut de Myologie, Laboratoire RMN, Paris, France, ²AIM, Institut de Myologie, Laboratoire de physiologie et d'évaluation neuromusculaire, Paris, France

In order to study the impact of aging on the skeletal muscle, we suggested several NMR based parameters that are water T2 values and heterogeneity indices related to water T2 changes. We evaluated this parameter on the quadriceps muscles of healthy young adults and older one. In addition to age, we considered the gender and physical activity factors. Results showed that water T2, and heterogeneities were higher for elderly group. Furthermore, a regular physical activity maintained lower muscle T2 values and heterogeneity indices. These findings may be related to the progressive atrophy and rarefaction of type II fibers with age.

Theodore F Towse^1,2, Christopher P Elder^1,3, Emily C Bush^4,5, Benjamin T Childs⁴, Samuel W Klockenkemper⁴, Shea A Sabin⁴, Jared T Bullock⁴, and Bruce M Damon^6,7
1Physical Medicine and Rehabilitation, Vanderbilt University, Nashville, TN, United States, ²Vanderbilt Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ³Radiology and Radiological Sciences, TN, United States, ⁴Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States,⁵Vanderbilt University Biomedical Engineering, TN, United States, ⁶Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, ⁷Molecular Physiology and Biophysics, Vanderbilt University, TN, United States

Post-isometric contraction proton density and T2*-weighted signal transients acquired at 3T have been used to characterize muscle microvascular function in both the normal and pathologic states. At 7T, muscle BOLD contrast is expected to be more influenced by extravascular BOLD mechanisms than is observed at 3T, where muscle BOLD contrast is dominated by intravascular mechanisms. Our preliminary studies suggest BOLD based functional imaging of muscle is feasible at 7T and may afford greater insight into microvascular dysfunction by offering greater specificity to microvascular-scale structures and a higher contrast-to-noise ratio than are achieved at lower field strengths.

Suzanne Scott¹, Luke Connolly¹, Sarah Jackman¹, Jonathan Fulford², Karen Knapp³, Jude Meakin³, Rosey Davies¹, and Peter Krustrup^1
1Sports and Health Science, University of Exeter, Exeter, United Kingdom, ²Exeter NIHR Clinical Research Facility, University of Exeter, Exeter, United Kingdom, ³CEMPS, University of Exeter, Exeter, United Kingdom

Adherence to exercise interventions aimed at improving cardiac health in sedentary women may be affected by lack of time to exercise. This study evaluated the efficacy and acceptability of short-bout football training (twice weekly for 13.5 min. over 16 weeks) in sedentary pre-menopausal women using 31P spectroscopy to assess metabolic adaptations in muscle. Results indicated a significant increase in time-to-failure on a ramp muscle test and a significantly higher end-exercise PCr value in participants after exposure to the training intervention. Evidence that shorter training regimes improve cardiac health may reduce barriers to exercise and increase compliance in target populations.

M. Kate Curtis¹, Lowri E. Cochlin², Mark A. Cole³, David P. O'Neill¹, Michael S. Dodd^1,4, Damian J. Tyler^1,4, Kieran Clarke¹, and Peter A. Robbins^1
1Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom, ²Department of Physiology, Anatomy and Genetics, PulseTeq Ltd, Oxford, United Kingdom, ³Department of Life Sciences, University of Nottingham Medical School, Nottingham, United Kingdom, ⁴Oxford Centre for Clinical Magnetic Resonance Research, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom

Physical work or exercise capacity has been widely reported as being impaired by iron deficiency in both human and animal studies. The aim of this project was to develop a technique that allows for the simultaneous assessment of force production, fatigue resistance and metabolic function of murine gastrocnemius muscle during exercise. To address this, a method of in vivo gastrocnemius muscle stimulation was successfully established, which allows the simultaneous measurement of energetics, by 31P MRS, and induced force production in a murine model of altered iron status.

Sara Maria Sprinkhuizen¹, Miriam Bredella², Martin Torriani², Anne Klibanski³, Pouneh K. Fazeli³, Scott Daley², Ela Jane Cross³, Jerome Ackerman¹, and Yi-Qiao Song^1,4
1MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, United States, ²MGH Musculoskeletal Imaging, MA, United States, ³MGH Neuroendocrine Unit, MA, United States, ⁴Schlumberger-Doll Research, Cambridge, MA, United States

Bone quality is currently measured with dual energy x-ray absorptiometry (DXA), which assesses the bone mineral density (BMD). However, BMD is just one of several factors contributing to bone quality. The microstructural geometry of bone is another, very important, factor in determining bone strength and can be measured using Decay due to Diffusion in the Internal Field (DDIF) MRI. The current work was aimed at understanding the relation between DDIF MRI and clinical BMD values. The DDIF technique was applied in the lumbar spine of healthy controls and patients with anorexia nervosa and compared to BMD values obtained using DXA.

Anna M. WANG^1,2, Iris Y. Zhou^1,2, Adrian Tsang^1,2, Ivy W. Han^1,2, and Ed X. Wu^1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, Hong Kong, ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, Hong Kong

This study explored the capability of proteoglycan (PG) T2 value as a marker of the intervertebral disc degeneration (IVDD). PG T2 and water T2 value, as well as PG/water ratio were measured on 4 different disc levels of lumbar spine. The PG T2 value showed a slightly increasing trend from the upper disc level to the lower disc level. The significant difference of PG T2 value was found between disc L3-4 and disc L4-5 while the water T2 and PG/water ratio showed no statistical significant change between disc levels. Our result suggests the increased PG T2 value could be the reflection of disc degeneration taken place. Demonstrated by this preliminary study, the PG T2 measurement on clinical scanner is highly feasible and the PG T2 value might be a potential marker for the early detection of disc degeneration.

Gaëlle Diserens¹, Mauricio Reyes², Chris Boesch¹, Peter Vermathen¹, and Waldo Enrique Valenzuela^2
1Depts Clinical Research and Radiology, University Bern, Bern, Bern, Switzerland, ²Institute for Surgical Technology and Biomechanics, Bern University, Bern, Switzerland

The aim of this study was to compare fat quantification determined by Dixon MRI, SVS and CSI in a back muscle (psoas major) in healthy subjects for small amounts of lipids only. A strong correlation was obtained for SVS and CSI results, but spectroscopy results didn't significantly correlate with Dixon results. Back muscle low fat content quantification can reliably be quantified by spectroscopy MR techniques (SVS and CSI), while noise and artefacts limit the preciseness of Dixon MRI for low fat quantification.

Yuchi Liu¹, Xunbai Mei¹, Nicola Lai^1,2, and Xin Yu^1,3
1Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States, ²Pediatrics, Case Western Reserve University, Ohio, United States, ³Radiology, Case Western Reserve University, Ohio, United States

This study investigated the metabolic response to ischemia in skeletal muscle of non-obese early stage type 2 diabetic rats. 31P spectra and BOLD images were acquired in an interleaved fashion at baseline, during 25-min ischemia, and 20-min reperfusion. The diabetic group showed less reduction in phosphocreatine (PCr) and less increase in inorganic phosphate (Pi) during ischemia. Diabetic rats also showed greater signal reduction in BOLD images during ischemia, possibly due to increased oxygen extraction. Both diabetic and control groups have similar PCr recovery kinetics during reperfusion. These data suggest that mitochondrial function may remain normal in early stage type 2 diabetes.

Jimin Ren¹, Baolian Yang², A. Dean Sherry^1,3, and Craig R. Malloy^1,4
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, ²Philips Healthcare, Ohio, United States, ³University of Texas at Dallas, Richardson, Texas, United States, ⁴VA North Texas Health Care System, Texas, United States

There has been a long-standing interest in measuring ATP synthesis rates in vivo. Conventional 31P saturation transfer requires prolonged saturation of gamaATP while inversion transfer by selective-inversion of gamaATP is less efficient, all due to rapid leaking of magnetization to other spins in the exchange network, especially phosphocreatine(PCr). Wideband inversion overcomes this problem by simultaneously inverting both PCr and ATP spins, allowing efficient transfer of magnetization to Pi. The advantage of wideband inversion is more evident at higher fields due to the increased PCr T1 value. The single 31P inversion pulse necessary for this technique is easy to implement.

Pierre G Carlier¹, Noura Azzabou¹, Paulo Loureiro de Sousa¹, Benoît Florkin², Emmanuel Deprez³, Norma B Romero⁴, Séverine Denis⁵, Valérie Decostre⁶, and Laurent Servais^7
1AIM-CEA Institut de Myologie, Laboratoire RMN, Paris, France, ²CHR La Citadelle, Service de Pédiatrie, Liège, Belgium, ³CHU de Liège, Service anatomie et cytologie pathologiques, Liège, Belgium, ⁴AIM, Institut de Myologie, Laboratoire d'histopathologie, Paris, France, ⁵Centre de référence des maladies neuromusculaires, CHR La Citadelle, Liège, Belgium, ⁶AIM, Institut de Myologie, Laboratoire de physiologie et d'évaluation neuromusculaire, Paris, France, ⁷AIM, Service Essais Cliniques et Bases de Données, Paris, France

The existence of oedematous/inflammatory/necrotic lesions is subjectively appreciated on T2-weighted images. Because it relies on identification of hyperintensities between and within muscles, the interpretation risk with T2-weighted images is to miss global, homogenous increases in T2. We demonstrate here this concern to be more than theoretical. Three patients aged 6, 7 and 12 were referred for suspicion of dermatomyositis. Standard T2w imaging was normal or subnormal. Quantitative T2 maps showed that muscle water T2s were abnormally elevated in the limb girdles and lower limbs. Quantitative T2 mapping can be required to detect unambiguously muscle lesions as here in juvenile dermatomyositis.

Ron Noah Alkalay¹, Dominik Meier², Carl-Fredrik Westin³, and David B Hackney^4
1Orthopedics, Beth Israel Deaconess Medical Center, Boston, MA, United States, ²Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States,³Radiology, Brigham and Women's Hospital, Boston, MA, United States, ⁴Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States

This study investigated the use of tensor diffusion imaging to directly interrogate the spatial orientation of collagen fibers’ in intact human disks. Four human lumbar cadaver spinal discs (L2-L3), age 48-52 years, were imaged in a 9.4 Tesla scanner. 3D (SE-EPI) diffusion tensor image data was acquired using 30 non-collinear directions. Collagen fibers orientation angle relative to the disk’s axial plane was computed at each voxel. DTI analysis showed clear demarcation between annulus and nucleus and the ability to count number of lamellae within the annulus. Analysis of fiber orientation showed fiber angle to increase as a function of region within the annulus.

Yoshiko Hayashida¹, Hodaka Oki¹, Michiko Kobayashi¹, Keita Watanabe¹, Shingo Kakeda¹, Takatoshi Aoki¹, and Yukunori Korogi^1
1Radiology, University of Occupational and Environmental Health,Japan, Kitakyushu, Fukuoka, Japan

Purpose Our purpose was to assess the fat fraction (FF) and R2* values (R2*) of the vertebrae in healthy subjects with IDEAL-IQ. Materials and Methods 75 patients underwent MRI including IDEAL-IQ and the mean FF and the mean R2* within the spine were evaluated. ANCOVA was performed to investigate gender age and BMI group differences. Results FF increased with advancing age and interaction with gender. Young females showed a low FF. The group of low BMI showed a low FF. Conclusion The quantitative analysis of the vertebrae with IDEAL-IQ can demonstrate those age gender and BMI-related changes.

Miyuki Takasu¹, Yoko Kaichi¹, Chihiro Tani¹, Shuji Date¹, Yuji Akiyama¹, Nobuhito Nango², and Kazuo Awai^1
1Diagnostic Radiology, Hiroshima University Hospital, Hiroshima, Hiroshima, Japan, ²Ratoc System Engineering, Tokyo, Japan

This study was performed to assess the relationship of 3T-MR- and MDCT-derived trabecular bone measurements with micro-CT measures as the gold-standard. L2 and L3 vertebral bodies of fresh human cadaver vertebrae were scanned. The under- and overestimation of parameters may be related to low spatial resolutions and susceptibility artifact. The MRI/MDCT-derived measurements correlated moderately with the gold-standards with the exception of Tb.Th. 3T MRI- and MDCT derived measures show significant correlations with micro-CT-derived parameters, suggesting that the two methodologies assess similar and complementary characteristics of bone.

Miyuki Takasu¹, Yoko Kaichi¹, Chihiro Tani¹, Shuji Date¹, Yuji Akiyama¹, Yoshiaki Kuroda², Akira Sakai³, and Kazuo Awai^1
1Diagnostic Radiology, Hiroshima University Hospital, Hiroshima, Hiroshima, Japan, ²Hematology, Hiroshima University Hospital, Hiroshima, Japan, ³Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan

The present study compared three fat-suppression techniques in terms of CNR and percent contrast and assessed the dependence of lesion conspicuity on BMPC% obtained from biopsy specimen. Significant negative correlations between percent contrast and CNR with BMPC% were demonstrated. We attributed this finding to increased signal intensity of background BM mainly caused by T2 prolongation by diffusely infiltrated myeloma cells, which can reduce the signal intensity contrast between focal lesion and background BM. In the low tumor load BM group, BM-focal lesion percent contrast was significantly greater for FS-T2 FSE than for the water image of IDEAL and STIR.

Delphine Perie^1,2, Maxime Huber^1,2, Guillaume Gilbert³, and Hubert Labelle^2
1Mechanical Engineering, Ecole Polytechnique de Montréal, Montreal, QC, Canada, ²Research Center, CHU Sainte Justine, Montreal, QC, Canada, ³Philips Healthcare, Montreal, QC, Canada

Scoliosis deformities progress more during skeletal growth, producing asymmetric loading. But the remaining question is why does scoliosis progress in some people but either does not progress or spontaneously corrects itself in others? We performed the first multi-parametric MRI acquisition in vivo on eight patients with adolescent idiopathic scoliosis. The results validated our hypothesis: T1rho, T2, MTR, ADC and FA within the intervertebral disc are modified in a specific way during scoliosis progression. The possibility to predict the evolution of the disc degeneration will allow a better target of the surgical or orthopaedic treatment than what is done today.

Joshua P. Jarman¹, Dennis J. Maiman², and L.Tugan Muftuler^3
1Medical college of Wisconsin, Milwaukee, WI, United States, ²Department of Neurosurgery, Medical college of Wisconsin, Milwaukee, WI, United States, ³Department of Neurosurgery and Center for Imaging Research, Medical College of Wisconsin, Milwaukee, WI, United States

The etiology of intervertebral Disc (IVD) degeneration is still not completely understood. Degenerating discs begin to lose proteoglycans, which is a water retaining molecule. With the decrease in water, the discs lose their ability to resist compression and torque. Eventually the discs begin to lose height and structural integrity. The goal of this study was to quantify various pathological changes during the course of disc degeneration using MRI biomarkers. We proposed a method to quantify disc height loss with degeneration and suggested that the decrease in IVD height would correlate with other biomarkers of degeneration.

Kaspar Josche Streitberger^1,2, Jing Guo¹, Gerd Diederichs¹, Sebastian Hirsch¹, Andreas Fehlner¹, Jürgen Braun³, and Ingolf Sack^1
1Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany, ²Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany,³Medical Informatics, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany

The noninvasive detection and quantification of the human intervertebral disk by MR elastography (MRE) could be beneficial for the diagnosis of chronic disk degeneration. This study presents the first in vivo measurement of viscoelastic constants of the human intervertebral disc by MRE. Multifrequency MRE and multifrequency wave field inversion was applied to 15 healthy volunteers one of whom was measured 7 times on 7 different days. The magnitude of the complex shear modulus measured in the nucleus pulposus (mean value 4.34 ± 1.2 kPa) shows a good reproducibility and correlates with the MRI morphology based Pfirrmann score.

Anna M. WANG^1,2, Adrian Tsang^1,2, Peng Cao^1,2, Danny Chan³, and Ed X. Wu^1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong, Hong Kong, ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, Hong Kong, ³Department of Biochemistry, The University of Hong Kong, Hong Kong

This study explored the capability of Diffusion Weighted Magnetic Resonance Spectroscopy (DW-MRS) to detect and characterize the ECM degradation during the early stage of IVDD. The apparent diffusion coefficient (ADC) of macromolecule resonances increased by approximately ten fold immediately after papain injection, and continued to increase in the following 5 days. The macromolecule T2 also had a slight increase during the ECM degradation and the macromolecule content is corrected by their corresponding T2 value. The macromolecule content, water T2 and ADC value showed a delayed change compared to the macromolecule ADCs. The macromolecule ADC is an early marker of the microstructural breakdown of PGs and collagen network in the disc NP during IVDD and hence DW-MRS is sensitive to detect disc degeneration at an early stage.

Niu Gang¹, Liu Zhe¹, Du Yong Hao¹, and Yang Jian^1,2
1Department of Radiology, the first affiliated hospital of medical college, Xi¡¯an Jiaotong University, Xi'an, Shaanxi, China, ²Department of Biomedical Engineering, School of Life Science and Technology, Xi' an Jiaotong University, Xi'an, Shaanxi, China

The aim of this study is to assess the feasibility of using intravoxel incoherent motion(IVIM) MRI in vivo to detect intervertebral disk degeneration(IVDD). 23 patients (14 men and 9 women; mean age 40 years; median age 47; age range 21~73 years) with low back pain or sciatica underwent IVIM MRI and T2 weighted images (T2WIs). It was showed that the pure diffusion ADClow of disk decrease with increased the Pfirrmann grades based on T2WI in this study, which indicated the decreased real diffusivity of free waterin IVDD. We also observed increased pseudodiffusion coefficient ADCfast values of AF with increased Pfirrmann grades,.The results demonstrated not only the significant differences in ADCfast of NP between grade I and IV, grade II and IV (ANOVA, P£¼0.05), but also the significant differences in ADCfast of AF between grade I and IV, II and IV, III and IV (ANOVA, P£¼0.05), which suggested an increasing microcapillary perfusionin IVDD. In sum, IVIM MR imaging may provide an objective and non-invasive biomarker for estimating diffusivity and microcapillary perfusion in IVDD.

L.Tugan Muftuler¹, Dhiraj Baruah², and Andrew Klein^2
1Department of Neurosurgery and Center for Imaging Research, Medical College of Wisconsin, Milwaukee, WI, United States, ²Department of Radiology, Medical college of Wisconsin, WI, United States

In some patients with low back pain, degenerative marrow changes are observed in the endplates around the degenerating intervertebral discs. These changes are classified based on the appearance of vertebrae in T1 and T2 weighted MRI. Type-1 changes usually involve early inflammatory changes and believed to play a role in pain generation. Type-2 changes generally involves conversion to fatty marrow. Although this classification is widely accepted, those images may not be sufficiently sensitive to early changes. Increases in T1 relaxation rate were reported in regions of inflammation in animals. Therefore, we tested the efficacy of T1 imaging in endplate degeneration.

Ephraim I Ben-Abraham¹, Jun Chen, Ph.D.¹, and Richard L Ehman, M.D.^1
1Radiology, Mayo Clinic, Rochester, MN, United States

Low back pain (LBP) is a very costly and prevalent health disorder in the U.S. Spinal instability and degenerative disc disease are two of the most common causes of LBP. It is known that the stiffness of the disc changes substantially with degeneration. MRE has been demonstrated for estimating the shear stiffness of the nucleus in the intervertebral disc in vitro. In this study, we attempt to measure spinal instability in an in vitro goat spine segment with induced disc degeneration and mechanical destabilization. Our results suggest MRE may be capable of detecting spinal instability.

Volkan Emre Arpinar¹, Dennis J Maiman¹, and L Tugan Muftuler^1,2
1Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States, ²Center for Imaging Research, Medical College of Wisconsin, WI, United States

The majority of chronic back pain is associated with degeneration of the intervertebral discs. Despite comprehensive studies, there is no consensus on the mechanisms of pathological degeneration or how it should be distinguished from the normal aging processes. One of the causes of degeneration is believed to be poor nutrient transport to the disc through the endplates. In this study, Dynamic Contrast Enhanced MRI was used to investigate the relation between disc degeneration and aberrations in nutrient transport to the discs. A compartmental model with standard kinetic parameters was implemented to study perfusion in endplates and adjacent subchondral bones.

Alexander C. Wright¹, Edward J. Vresilovic², and Dawn M. Ellliott^3
1Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Department of Orthopaedics and Rehabilitation, Penn State University, Hershey, PA, United States, ³Department of Biomedical Engineering, University of Delaware, Newark, DE, United States

The purpose of this study is to provide a theoretical model for the visibility (image contrast) of collagen lamellae in the annulus fibrosus as seen in MRI. The model is based on the assumption of a dipolar term in the T2 relaxation mechanism of water protons and that the observed anisotropic modulation of signal intensity reflects the underlying microstructure of collagen fibers.

Avneesh Chhabra^1,2, Sahar Farahani², Gaurav Thawait², John A Carrino², and Allan Belzberg^3
1Radiology, UTSW, Dallas, Texas, United States, ²Radiology, Johns Hopkins, Baltimore, Maryland, United States, ³Plastic surgery, Johns Hopkins, Baltimore, Ma, United States

MRI of lumbar spine is the current non-invasive imaging study of choice for bone and soft tissue evaluation. For suspected radiculopathy, therefore, it is reasonable to start with conventional MRI. However, MRI findings can be frequently non-contributary despite unilateral radiculopathy symptoms clinically, either due to not being able to reveal the problem or showing disc herniations at multiple levels. High resolution MR Neurography along with diffusion tensor imaging sequences can provide additional information in patients with radiculopathy. This prospective pilot study shows how more advanced pulse sequences could add new or different information compared to conventional MRI and explain the symptoms of radiculopathy.

Delphine Perie^1,2, Clemence Balosetti^1,2, Sofiane Achiche¹, and Hubert Labelle^2
1Mechanical Engineering, Ecole Polytechnique de Montréal, Montreal, QC, Canada, ²Research Center, CHU Sainte Justine, Montreal, QC, Canada

In both scoliosis and spondylolisthesis, the progression of the spine deformation leads to the degeneration of intervertebral discs characterized by a change in its structure and biochemical composition. The MRI images of 79 patients (32 with scoliosis, 32 with spondylolisthesis and 15 with herniated discs) were analysed using texture parameters extracted from the intensity histograms of the grey level, contrast, correlation, energy and homogeneity images. The results validated our hypothesis: the calculated tissue-specific texture features can effectively discriminate the pathologies and some of their severities. This method has the advantage of supporting the interesting possibility of developing robust non-invasive predictive methods for the diagnosis of the severities of spine pathologies.

Jianming Hua¹, Chengzhen Liang², Risheng Yu¹, and Minming Zhang^1
1Department of Radiology, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China, ²Department of Orthopedic Surgery, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China

To investigate a slowly progressive, reproducible rat model of disc degenerationsuitable for studying the participating mechanisms induced by needle puncture, and the relationship between MRI and histology in the long-term progression of disc degeneration.

Yi-Jui Liu¹, Cheng Teng Chieh¹, Yi-Hsiung Lee², and Wing P. Chan^3
1Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan, ²Ph.D program in Electrical and Communication Engineering, Feng China University, Taichung, Taiwan, ³Department of Radiology, Taipei Medical University - Wan Fang Hospital, Taipei, Taiwan

Because of the inhomogeneous perfusion in vertebral body and only enrolled partial volume of vertebral body using one slice image, it is reasonable to make an assumption that the bias should be present in DCE-MRI examination. However, one slice DCE-MRI was usually performed in most research for temproal resolution. In this study, this hypothesis that blood perfusion is regional dependent in vertebral body was demonstrated using three middle sagittal, middle coronal and whole axial plane in thick axial slice data. The divergences of peak enhancement, wash-in and wash-out slope among three planes were investigated in 70 healthy vertebras.

Young Han Lee¹, Jin-Suck Suh¹, and Eunju Kim^2
1Radiology, Yonsei University College of Medicine, Seoul, 120-752, Korea, ²Philips Healthcare, Korea

Magnetic resonance (MR) imaging plays an important role in the postoperative evaluation of patients. Fluid sensitive fat-suppressed MR imaging is especially important in postoperative evaluation. However, metallic artifacts are inevitable with MR imaging, and these metallic artifacts are aggravated by using fat-saturation. We thought the combination of advanced metal-artifact-reducing MR technique and fat suppression would be useful in metallic MR imaging. Considering the advantages of 3T MR imaging of the spine such as an increase in SNR with optimized diagnostic quality and improved clinical impact, implementing fat-suppressed SEMAC-corrected at 3T MR is a major goal in metallic MR imaging.

Yasuhiko Terada¹, Daiki Tamada¹, Tomomi Uchiumi¹, Keiichiro Ishi¹, Katsumi Kose¹, Taiki Nozaki², Yasuhito Kaneko², and Hiroshi Yoshioka^2
1Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan, ²Department of Radiological Sciences, University of California Irvine, Orange, CA, United States

Skeletal age of a child can be evaluated by MR images of bones in the left hand. The hand imaging for young subjects often suffers from motion artifacts. Shortening the scan time provides an effective solution. Compressed sensing (CS) is a promising technique, but an image is not highly compressive when the signal-to-noise ratio (SNR) is low, and the CS application to bone imaging using a low-field MRI remains a challenge. Here we explore the possibility of CS-based acceleration of bone imaging with the 0.3T open compact pediatric hand scanner. We further show the validity of CS-based skeletal examination.

Matthew F. Koff¹, Stephanie L. Gold¹, Brett Lurie¹, Danyal H. Nawabi¹, Geoffrey Westrich¹, and Hollis G. Potter^1
1Hospital for Special Surgery, New York, NY, United States

Wear of at the neck-stem junction in modular total hip arthroplasty is associated with adverse local tissue reaction (ALTR) and premature implant failure. This study identified MR imaging findings characteristic of a failing modular THA system and determined which are most indicative of an ALTR, as confirmed by histology following revision arthroplasty. A majority (60%) of symptomatic hips had a moderate to severe ALTR. Synovial thickness was positively correlated with histologic scoring (= 0.734, p<0.0003). Using MRI to measure synovial thickness may identify a premature failing hip and help guide surgical management in patients with ALTR.

Marco Vicari^1,2, Kaywan Izadpanah³, Andrea Serra⁴, Iulius Dragonu², Guobin Li², Maddalena Strumia^2,5, and Juergen Hennig^2
1Esaote S.p.A., Freiburg, Germany, ²Dept. of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, ³Dept. of Orthopedics and Trauma Surgery, University Medical Center Freiburg, Freiburg, Germany, ⁴Esaote S.p.A., Genoa, Italy, ⁵Deutsches Konsortium für translationale Krebsforschung (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany

An interesting clinical application of MRI near metal implants consists in checking the functionality of the acromio-clavicular joint of the shoulder after treatment by bone fixation with metal plates. The overall acquisition time is usually very long, since imaging at different abduction degrees of the shoulder is required, with a quite demanding spatial resolution to allow precise quantitative evaluations. Accelerated 3D RARE imaging for open-configuration, tilting MRI scanners at low-field well suits this clinical task, since it allows, within reasonable acquisition times, positional MRI under physiological weight-bearing with sensibly less metal-induced artifacts in comparison with high-field scanners.

Mark W. J. M. Gosselink¹, Joep van Oorschot¹, Alexandra de Rotte¹, Fredy Visser¹, Peter R Luijten¹, Mies A Korteweg², Hanneke J. J. Bluemink¹, and Dennis W. J. Klomp^1
1Radiology, UMC Utrecht, Utrecht, Utrecht, Netherlands, ²Radiology, AMC Amsterdam, Amsterdam, Noord-Holland, Netherlands

The classification of cartilage in the wrist by means of T₁MRI requires ultra-high spatial resolutions. While T₁sequences coincide with long and strong B1+ fields, we demonstrate that a SAR optimized coil can provide uncompromised T₁MRI of the wrist even at 7T. Demonstrated with strong and uniform spin locking fields, combined with 32 channel receivers, quantified 0.5 mm isotropic T₁are obtained of cartilage in the wrist.

Tom Amies¹, Kanimozhi Vendhan², Debajit Sen³, Corrine Fisher³, Yiannis Ioannou³, Paul Humphries², and Margaret Hall-craggs^2
1Radiology, University College Hospital, London, London, United Kingdom, ²Radiology, University College Hospital, London, United Kingdom, ³Rheumatology, University College Hospital, London, United Kingdom

Enthesitis related arthritis (ERA) is a form of juvenile arthritis which presents with a varying degree of apophyseal joint inflammation and/or sacroiliitis. We present a retrospective review of serial MRI scans correlating the changes in apophyseal joint inflammation and sacroiliitis. Images were reviewed independently by two expert MR readers using a global visual assessment and a numerical scoring method. We correlated these findings with the therapeutics the patients were receiving at the time of the scans. We have found that concurrent sacroiliitis and apophyseal joint synovitis in patients with ERA can respond independently of one another whilst on conventional therapy.

Wingchi Edmund Kwok^1,2, Zhigang You¹, and Christopher Ritchlin^3
1Department of Imaging Sciences, University of Rochester, Rochester, New York, United States, ²Rochester Center for Brain Imaging, University of Rochester, Rochester, New York, United States, ³Department of Medicine, University of Rochester, Rochester, New York, United States

With the use of a dedicated RF coil and a modified pulse sequence at 3T, we conducted high-resolution non-contrast-enhanced time-of-flight MR angiography of fingers on two normal subjects, and compared the results with data acquired using the highest resolution we found in finger MRA studies by other groups. Our higher-resolution images give sharper and more definitive depiction of the blood vessels, enabling better visualization of the geometry and connectivity of the blood vessels as well as the relationship between the vessels. Our technique should be useful for the diagnosis, treatment assessment and pathogenesis studies of arthritis and systemic sclerosis.

Chen Lin¹, Kecheng Liu², Bruce Spottiswoode², and Kenneth Buckwalter^1
1Radiology and Imaging Science, IU School of Medicine, Indianapolis, IN, United States, ²Siemens Medical Solutions, USA Inc., PA, United States

MRI of patients with hip prostheses remains a challenge, particularly at 3T. Through phantom and volunteer studies, a set of optimized protocols for metal artifact reduction (MAR) using view angle tilting (VAT) and slice encoding metal artifact correction (SEMAC) was found to produce diagnostic information within a clinically acceptable scan time at 3T. For prostheses made of non-magnetic alloys, the degree of MAR approaches that of 1.5T.

Malcolm A West¹, Lisa Loughney², Michael PW Grocott³, Sandy Jack³, and Graham J Kemp^1
1Magnetic Resonance and Image Analysis Research Centre, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, Merseyside, United Kingdom,²Critical Care Research Area, NIHR Respiratory BRU, University Hospital Southampton, Southampton, Hampshire, United Kingdom, ³Integrative Physiology and Critical Illness Group, Faculty of Medicine, University of Southampton, Hampshire, United Kingdom

This prospective study of 12 locally advanced rectal cancer patients aims to investigate the effects of standardised neoadjuvant chemoradiotherapy (NACRT) on objectively measured mitochondrial energetics and physical fitness using 31-phosphorus magnetic resonance spectroscopy (31P MRS) and cardiopulmonary exercise testing (CPET). A significant reduction in oxygen uptake at estimated lactate threshold, oxygen uptake at Peak exercise (ml.kg-1.min-1), and a parallel decrease in post-exercise phosphocreatine (PCr) recovery rate constant (kPCr min-1 suggests that mitochondrial mechanisms are important in the loss of fitness induced by NACRT.

Jonas Bürk¹, Philippe Dovi-Akue¹, Matthias Benndorf¹, Benjamin Fritz¹, Philipp Lenz¹, and Tobias Baumann^1
1Radiology, Universitiy Hospital Freiburg, Freiburg, Baden Württemberg, Germany

In comparison to high field MR-scanners, the main disadvantages of low field MR-scanners are reduced signal-to-noise Ratio (SNR) and resolution in comparison with higher magnetic field strength. Despite these limitations, several publications which compared low field MRI to arthroscopy showed good sensitivity and specificity for the detection of cruciate ligament ruptures and meniscus lesions. Since there are no publications using low field MR-scanners of the newest generation so far, the objective of this study was to analyze the capabilities of low field MR-scanner of the newest generation in the detection of musculoskeletal knee injuries of acute trauma patients in comparison to the gold standard (arthroscopy and CT). In our study we observed very good sensitivity and specificity in the diagnosis of traumatic meniscal tears, ACL tears as well as fractures with low field MRI. Advantages of low field MRI are the reduced costs for purchasing and maintenance. It follows that high patient throughput based on economic pressure is not necessary, allowing to keep examination slots free for acute trauma patients.

Leon C. Ho^1,2, Ian A. Sigal³, Ning-Juan Jan³, Hunter Mehrens¹, Alexander Squires⁴, Zion Tse⁴, Ed X Wu², Joel S. Schuman³, Seong-Gi Kim^1,5, Tao Jin¹, and Kevin C Chan^1,3
1Neuroimaging Laboratory, Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States, ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China, ³Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States,⁴Medical Robotics Lab, College of Engineering, The University of Georgia, Athens, Georgia, United States, ⁵Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Dept. of Biological Sci, SKKU, Suwon, Korea

Sclera is a fibrous connective tissue in the outer coat of the eye which may undergo microscopic structural reorganization under different physiological environments. Ocular hypertension may apply tensile stress to sclera leading to microstructural changes. However, there are limited non-invasive technique available. In this study, we demonstrated the feasibility of using magic angle enhanced MRI in different MR contrasts to detect magnetic tissue property changes in scleral fibers of and normotensive and hypertenive eyes.

Ryusuke Nakai¹, Takashi Azuma², Keiji Shigeno¹, Mariko Wakatsuki¹, Guoxiang Liu², Osamu Takizawa³, and Hiroo Iwata^1
1Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan, ²Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka, Japan, ³Siemens Japan K.K., Tokyo, Japan

In the current study, a technique was developed for continuous time-series mandibular imaging of multiple sections with analysis of time-series data and automatic measurement of the three-dimensional positions and rotation angles of the mandibular movement. The utility of this technique was evaluated by analysis of mandibular movement in volunteers. As a result, the automatic measurement technique had very good precision. This technique gives precise information that can facilitate diagnosis of temporomandibular joint disorder and mandibular movement disturbance. Therefore, this technique should permit rapid diagnosis of symptoms and disorders by dentists.

Stefan Wundrak¹, Jan Paul¹, Johannes Ulrici², Erich Hell², and Volker Rasche^1
1Ulm University Hospital, Ulm, Germany, ²Sirona Dental Systems, Bensheim, Germany

Assessment of the masticatory motion of the temporomandibular joint (TMJ) is of interest for a variety of pathologies, e.g. the abnormal motion of the articular disc. In this contribution we use k-t radial sparse SENSE for the imaging of the TMJ dynamics to increase the achievable spatiotemporal resolution. While previous methods enabled dynamic TMJ imaging without motion blur at 15 to 50 seconds per opening-closing cycle, the proposed methods enables the imaging of the TMJ at opening-closing cycle times of 4 to 8 seconds.

Anna-Katinka Bracher¹, Volker Rasche¹, Erich Hell², Johannes Ulrici², and Axel Bornstedt^1
1Internal Medicine II, University Hospital of Ulm, Ulm, BW, Germany, ²Sirona Dental Systems, Bensheim, HE, Germany

The diagnosis of apical periodontitis and the differentiation between acute and chronic lesions with MRI requires images of identical anatomy with different contrasts (T1w and T2w). A reduction of examination time can be obtained by sharing the information of high frequency components of k-space. Using the information of an high resolution reference scan (T1w) a high resolution multi contrast image of a low-resolution T2w scan of the same anatomy can be provided.

Michael H Buonocore¹, Robert D Boutin¹, Igor Immerman², and Abhijit J Chaudhari^1
1Radiology, UC Davis, Sacramento, CA, United States, ²Orthopedic Surgery, UC Davis, Sacramento, CA, United States

This abstract describes the use of undersampled cartesian and radial k-space acquisition, combined with iterative, cost-function based image reconstruction for rapid real-time imaging of the moving wrist. The techniques provide sufficient image quality for observation and quantitative measurement of changing carpal bone angles and distances during the motion, and spatial and temporal resolution of the image set can be flexibly traded-off as part of reconstruction after the k-space data has been collected. These measurements are important for assessment of carpal bone instability, tendon dislocation, and other pathologies of wrist joint action.

Young Han Lee¹, Jin-Suck Suh¹, and InSeong Kim^2
1Radiology, Yonsei University College of Medicine, Seoul, 120-752, Korea, ²Siemens Healthcare, Korea

Classification of RCT using shoulder MR imaging is traditionally based on tear width and thickness, not arthroscopic classification. However, for surgical RCT repair, arthroscopic classification is more useful because the surgical method depends on the classification type. For example, U-shaped tears can be repaired by margin convergence whereas crescent-shaped tears can be repaired directly by a tendon-to-bone technique. We believe the ability to determine surgical classification of RCT type with preoperative MR imaging could be helpful, especially with recently introduced three-dimensional (3D) MR sequences.

Kanimozhi Vendhan¹, David Atkinson², Debajit Sen³, Corinne Fisher³, Yiannis Ioannou⁴, Paul Bassett⁵, and Margaret Hall-Craggs^6
1UCLH, London, London, United Kingdom, ²UCL, London, United Kingdom, ³UCLH, London, United Kingdom, ⁴Arthritis Research UK Centre for Adolescent Rheumatology, UCL, London, United Kingdom, ⁵Statsconsultancy Ltd, London, United Kingdom, ⁶Imaging Department, UCLH, London, United Kingdom

This was a retrospective case-control study to quantify sacroiliitis in patients with juvenile arthritis by using ADC maps. Along with conventional sequences, DWI of the sacroiliac joints (SIJs) was performed at multiple b values. A Matlab program was written to create a profile of ADC values across the SIJs and a reference sample in normal bone. This was done by manually drawing a multiple linear regions of interest, centered on the SIJ. There was a highly significant difference between the ADC area scores of the cases and controls. This novel technique for quantifying sacroiliitis could potentially be used to monitor response to therapy.

Katharine J Wilson¹, Jurgen Fripp², Kaikai Shen², Rachel K Surowiec¹, and Charles P Ho^1
1Steadman Philippon Research Institute, Vail, CO, United States, ²CSIRO Computational Informatics, The Australian eHealth Research Centre, Queensland, Australia

Chronic posterior cruciate ligament (PCL) injuries are often affected by degeneration with symptoms including thickening and elongation of the ligament. Conventional diagnosis with MRI has proven variable therefore the ability to quantify the shape of the ligament may prove valuable. The purpose of the study was to characterize the normal shape variations in an asymptomatic population of PCLs using statistical shape models (SSM) derived from MRI. We observed a significant difference in absolute volumes between age and gender groups and present the anatomical variability in a cohort of 27 asymptomatic PCLs analyzed using SSM.

Joshua Michael Farber¹, Saara Totterman², Jose Tamez-Pena³, Edward Schreyer², and Karl Baum^2
1Radiology, Qmetrics Technologies, Cincinnati, Ohio, United States, ²Radiology, Qmetrics Technologies, Rochester, NY, United States, ³Bio Sciences, Tec De Monterry, Monterry, Monterry, Mexico

OA repair techniques are becoming ubiquitous, inlcuding autograft and allograft repairs. This material explores the feasibility of using routine 3D FS DESS, 3D PD FS FSE and 2D PD FS FSE at 1.5 T to generate 3D articular cartilage (AC) thickness maps with an atlas based, voxel by voxel automated segmentation platform.

Alexey Shukelovich^1,2, Pierre-Yves Baudin¹, Noura Azzabou¹, Pierre G Carlier¹, Jean-Marc Boisserie¹, and Julien LeLouer^1
1AIM-CEA Institut de Myologie, Laboratoire RMN, Paris, France, ²The United Institute of Informatics Problems of the National Academy of Sciences of Belarus, Minsk, Belarus

In this work we present a user-friendly interactive segmentation tool that is handy and suitable for clinicians and is developed to improve, accelerate and facilitate MRI muscle segmentation process. Segmentation software is built on the top of ITK-SNAP and incorporates a new segmentation tool based on a robust semi-automatic random walker algorithm. Experimental segmentation was done on a human thigh muscle MRI dataset and compared to a manual segmentation using relative volume differences and Dice coefficients. We have achieved a sufficient acceleration in segmentation process with minor loss of segmentation quality.

Roula Bou Sader¹, William B. Morrison², Alex Dresner², Luke Maj², Yulia Gombar², and Adam Zoga^2
1Radiology, Thomas Jefferson University Hospital, Philadelphia, PA, United States, ²Thomas Jefferson University Hospital, PA, United States

We sought to optimize direct MR arthrography by determining the optimal concentration of three contrast agents. Magnevist, Gadavist and Optimark dilutions were scanned at 1.0, 1.5T, and 3.0T. On T1-SE, all contrast agents tested showed peak signal at a dilution of 2.0-2.6 mmol/L. On FSE-PD and T2, signal decreased rapidly with increasing concentrations. On 2D-GRE, there was less variation in signal intensity, with a peak at 2.0 mmol/L for each contrast agent. On STIR imaging two peaks were observed, one at the minimum concentration and another at 4.0 mmol/L. There was very little difference between contrast agents tested.