Alex Menys¹, Shamaila Butt², Anton Emmanuel², Natalia Zarate², David Atkinson³, Andrew Plumb³, and Stuart A Taylor^3
1Centre for Medical Imaging, UCL, London, Select, United Kingdom, ²GI Physiology Unit, UCLH, London, United Kingdom, ³Centre for Medical Imaging, UCL, London, United Kingdom

Quantified small bowel (SB) motility, assessed by analysis of dynamic MRI images, is an emerging tool for the investigation of dysmotility in a range of diseases. In this study, we report the initial findings with respect to global SB motility in a group of Chronic Intestinal pseudo-obstruction patients against healthy controls. We found a significant difference in basal small bowel motility between groups and, upon challenge with a pro-kinetic drug, increases in bowel motility in both groups. This study demonstrates the first clinical application of global SB motility analysis and encouraging results for the quantitative investigation of dysmotility in disease.

Gemma Chaddock¹, Ching Lam², Klara Garsed², Caroline Hoad¹, Carolyn Costigan¹, Susan Pritchard¹, Luca Marciani², Robin Spiller², and Penny Gowland^1
1Physics & Astronomy, The University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, ²NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals Trust, Nottingham, Nottinghamshire, United Kingdom

We have assessed the colonic response of patients with chronic constipation (CC) to a laxative, using novel MRI methods. 40 patients took part in this one day open label study where serial MRI was used to assess whole gut transit time, small bowel water content, colonic volumes and colonic motility following oral ingestion of 1 L of a macrogol based laxative. We found quantifiable differences between the colonic responses of patients with different types of CC following ingestion of the laxative. This presents the opportunity to differentiate between patients with different forms of CC, allowing for more personalised treatment.

Caroline L. Hoad¹, Valentin Hamy², Klara Garsed³, Luca Marciani³, Robin C. Spiller³, Stuart A. Taylor², David Atkinson², Penny A. Gowland¹, and Alex Menys^2
1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, ²Centre for Medical Imaging, Division of Medicine, UCL, London, United Kingdom, ³Nottingham Digestive Disease Centre, Biomedical Research Unit in GI and Liver Diseases, University Hospitals NHS Trust and University of Nottingham, Nottingham, Nottinghamshire, United Kingdom

This study describes a preliminary investigation of the use of registration techniques to assess colonic motility. Cine MRI data from 10 healthy subjects pre- and 1 hour post an oral dose of a common laxative underwent dual registration to remove breathing effects and parameterise bowel motion. Significant area changes from 3 regions of interest across the AC were converted into a motility index and compared to observer scores of bowel wall contractions. The greatest agreement between the motility index and observer scores were seen for a change in area of greater than 5% of mean area.

Eugene G. Kholmovski^1,2, Layne Norlund², Matthew Shonnard³, Hilary Riley³, and Grant W. Hennig^3
1UCAIR, Department of Radiology, University of Utah, Salt Lake City, Utah, United States, ²CARMA Center, University Of Utah, Salt Lake City, Utah, United States, ³Department of Physiology & Cell Biology, University of Nevada, Reno, Nevada, United States

The use of MRI to study gastric motor function is limited and has mostly concentrated on quantifying volumes during gastric emptying [1]. Other important determinates of gastric motor function such as the velocity, frequency, and direction of antral peristaltic contractions have been more difficult to measure due to temporal undersampling and diaphragmatic distortion issues. We have developed MR image acquisition and data analysis methods to better ascertain how propagating antral contractions affect gastric emptying in health and disease.

Jean A Tkach¹, Mantosh S Rattan¹, Charles L Dumoulin¹, and Andrew P South^2
1Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States, ²Neonatology and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States

Preterm and term neonates are at high risk of intestinal motility disorders. In older children and adults, cine MRI has proven useful in diagnosis and management of intestinal motility disorders. However, the standard technique includes breath holding and oral bowel preparation—procedures that cannot safely or practically be applied to neonates. In this study, cine MRI was obtained to assess intestinal motility in a cohort late preterm and term neonates. The qualitative and quantitative analysis of the motility data were consistent with that reported for adults, demonstrating cine MRI as a viable method to assess intestinal function in neonates.

Zi Wang¹, Hao Tang¹, Xiaoyan Meng¹, Jianjun Li¹, and Daoyu Hu^1
1Tongji Hospital,Tongji Medical College of Huazhong University of Science and Technology,Wuhan,China, Wuhan, Hubei, China

Function of small bowel motility is essential to sustain life, especially for patients suffering from small bowel diseases by whom those invasive examination such as intraluminal manometry may not be tolerated. In this study, dynamic MR series was used to evaluate the small bowel motility in healthy volunteers and patients with various kinds of organic small bowel diseases. Several types of abnormal peristalsis in patients group were differentiate from those in healthy volunteers.Clinician could make a more comprehensive view on the small bowel function in patients with organic small bowel diseases with the additional information provide by cine MR.

Richard Syms¹, Chris Wadsworth², Ian Young¹, Marc Rea², and Simon Taylor-Robinson^2
1EEE Dept., Imperial College London, London, Middlesex, United Kingdom, ²St Mary's Hospital, Imperial College London, London, Middlesex, United Kingdom

Endoscopic ultrasound (EUS) is a well-established, safe modality for real-time imaging of the duodenum and nearby ductal systems. However, all echo-ranging imaging suffers from artifacts, the most significant being reverberation between impedance discontinuities. As a result, concentric artifacts dominate the near field. These artifacts cannot be suppressed without eliminating the fundamental contrast mechanism, unless a nonlinear contrast agent is used. As a result, EUS images are hard to interpret, and repeated scans are required. Although slower, internal MRI may therefore offer advantages. The aim of this paper is to compare the performance of a new MR-imaging duodenoscope with EUS.

Iva Petkovska¹, Bobby Kalb¹, Shannon Urbina¹, Matt Covington¹, Puneet Sharma¹, Hina Arif¹, and Diego Martin^1
1Medical Imaging, The University of Arizona, Tucson, Arizona, United States

To evaluate the sensitivity and specificity of MRI for the detection of acute appendicitis in patients less than or equal to 40 years old presenting to the emergency department (ED) with right lower quadrant pain (RLQP), primarily using only single shot partial Fourier spin echo-train T2 weighted images with and without fat-suppression, and without the use of either intravenous (IV) or oral contrast agents. We demonstrate that MRI is a highly accurate test for the evaluation of patients less than or equal to 40 yo with acute RLQP and a differential diagnosis of acute appendicitis utilizing a rapidly acquired imaging protocol that is relatively insensitive to breathing-related motion and performed without use of IV or oral contrast.

Justin M Ream¹, Ankur M Doshi¹, Kai Tobias Block¹, Sungheon Kim¹, Ricardo Otazo¹, Li Feng¹, and Hersh Chandarana^1
1Radiology, NYU Langone Medical Center, New York, NY, United States

GRASP imaging enables excellent spatial and temporal resolution for dynamic contrast enhanced MRI imaging of the small bowel.

Douglas Andrew Pendse¹, Jesica Makanyanga¹, Andrew Plumb¹, David Atkinson¹, and Stuart Taylor^1
1Centre for Medical Imaging, University College London, London, London, United Kingdom

Therapeutic strategies in Crohn’s disease are dependent on both the degree of disease activity and the overall burden of disease in the gut. In this study we evaluated diffusion MRI (DWI) of the bowel in 69 adult patients with Crohns disease, using validated methods of MEGS score on MR-Enterography (MRE) and fecal Calprotectin (fC) as reference standards. Patients with abnormal DWI were shown to have significantly higher levels of fC and had higher MEGS score on conventional MRE. These data suggest that diffusion MRI is a clinically useful tool in the evaluation of Crohn’s activity.

Dian Liu¹, Jelena Curcic^1,2, Sebastian Kozerke¹, and Andreas Steingoetter^1,2
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ²Division of Gastroenterology and Hepatology, University of Zurich, Zurich, Switzerland

A combined dual-flip angle, dual repetition T1B1 mapping scheme has been previously validated for in vivo quantification of gastric secretion and mixing. Practical limitation of this approach is the need for multiple breath hold cycles and its sensitivity to motion and flow. This study evaluates the combination of the novel rapid B1 mapping technique DREAM with slice profile correction and the dual-flip angle T1 mapping scheme for robust T1 quantification of gastric content during a single breath hold with improved co-registration of T1 and B1 maps.

Kathryn Murray¹, Deanna Mudie², Susan Pritchard¹, Caroline Hoad¹, Martin Garnett³, Gordon Amidon², Penny Gowland¹, Robin Spiller⁴, Gregory Amidon², and Luca Marciani^4
1Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, Nottingham, United Kingdom, ²College of Pharmacy, University of Michigan, MI, United States, ³School of Pharmacy, University of Nottingham, Nottingham, United Kingdom, ⁴Nottingham Digestive Diseases Centre and Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, United Kingdom

Drug dissolution and absorption from solid oral dosage forms is highly dependent on the presence of liquid in the gut, but little is known about liquid volumes and distribution in vivo. This study detailes the time courses of the volume and number of liquid pockets in the upper gut of 12 healthy individuals following the ingestion of the industry standard 240 mL dose of water using MRI. These novel insights will help improve physiological relevance of modeling for prediction of bioperformance of low solubility oral solid dosage forms.

Andreas M. Loening¹, Pejman Ghanouni¹, Joseph Y. Cheng², Marcus T. Alley¹, and Shreyas S. Vasanawala^1
1Dept. of Radiology, Stanford University School of Medicine, Stanford, CA, United States, ²Electrical Engineering, Stanford University, Stanford, CA, United States

Standard MRI imaging of perianal fistulas utilizes multiple planes of T2 weighted sequences in addition to pre and post-contrast imaging. To decrease the length of time these studies require, we demonstrated that a fast protocol utilizing a single plane of T2 in combination with a high-resolution free-breathing post-contrast 3D SPGR sequence (with appropriate reformats derived during post-processing) was equivalent to a conventional protocol in the evaluation of perianal fistulas. This greatly reduces total scan time from 30-40 minutes to less than 15, and may in fact improve diagnostic accuracy.

Xi sheng Cao¹, Xiang Zheng¹, Xiang yi Liu¹, Chun miao Hu², Wei Wei², and Yun bin Chen^3
1Department of Radiology, Provincial Clinical College of Fujian Medical University, Fuzhou, Fujian, China, ²Department of Radiology, Fujian Provincial Cancer Hospital, Fuzhou, Fujian, China, ³Department of Radiology, Provincial Clinical College of Fujian Medical University,Fujian Provincial Cancer Hospital, Fuzhou, Fujian, China

This paper is to assess the reproducibility of diffusional kurtosis imaging(DKI) for rectum in volunteers under normal breathing with background body signal suppression.

Utaroh Motosugi^1,2, Diego Hernando¹, Peter Bannas^1,3, James H. Holmes⁴, Kang Wang⁴, Ann Shimakawa⁵, Yuji Iwadate⁶, Valentina Taviani⁷, and Scott B. Reeder^1,8
1Radiology, University of Wisconsin, Madison, WI, United States, ²Radiology, University of Yamanashi, Chuo-shi, Yamanashi, Japan, ³Radiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany, ⁴Global MR Applications and Workflow, GE Healthcare, Madison, WI, United States, ⁵Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States, ⁶Global MR Applications and Workflow, GE Healthcare, Hino, Tokyo, Japan, ⁷Radiology, Stanford University, Stanford, CA, United States, ⁸Medical Physics, Biomedical Engineering and Medicine, University of Wisconsin, Madison, WI, United States

Proton density fat fraction (PDFF) is a promising biomarker for early detection and treatment monitoring of fatty liver disease. In order to obtain whole-liver coverage, current chemical shift-encoded MRI requires breath-holding for ~20s. In this study, we established two new free-breathing chemical shift-encoded MRI methods to acquire PDFF maps, and compared these methods to breath-hold MRI and MR spectroscopy. We found that the free-breathing methods (respiratory-gating with bellows or navigator echoes) were both equivalent to the breath-hold sequence for liver fat quantification. These novel sequences may be helpful for pediatric patients or patients who are unable to perform breath-holding.

Carolina Arboleda Clavijo¹, Daniel Aguirre-Reyes¹, Cristián Tejos¹, Loreto Muñoz², Catalina Carvajal², Pablo Irarrazaval¹, Marcelo Andia³, and Sergio Uribe^3
1Department of Electrical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile, ²Chemistry and Bioprocesses Department, Pontificia Universidad Católica de Chile, Santiago, Chile, ³Department of Radiology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile

We present a 3D 3-point Dixon liver fat imaging sequence with real-time respiratory self-gating to quantify fat fraction in the liver. The respiratory self-gating method monitors the breathing motion by acquiring a center k-space profile and adjusts the acquisition scheme to reacquire motion-corrupted data. To prove the applicability and precision of the technique, we performed experiments in a phantom consisting of several water-fat emulsions and in 13 volunteers. The results obtained show that the proposed method yields more precise fat fraction maps of the entire liver in a single free breathing scan than the current gold-standard method.

Silke Hey¹, Elwin de Weerdt¹, Adri Duijndam¹, Ivan Dimitrov², and Liz Moore^1
1Clinical Excellence, Philips Healthcare, Best, Netherlands, ²Philips Healthcare, Texas, United States

Methods based on the Dixon technique are increasingly used to quantify the triglyceride fat content of the liver. The employed pre-defined spectral model of triglyceride fat is very sensitive to modulations in spectral peak positions and amplitudes. Temperature and local susceptibility changes are known to induce shifts of the fat spectrum with respect to the water peak. In this study, we demonstrate the impact of temperature on the accuracy of measured fat fraction values which might be of high importance for a future standardization of Dixon based fat quantification methods.

Puneet Sharma¹, Xiaodong Zhong², Jean-Philippe Galons³, Bobby Kalb³, Maria Altbach³, and Diego R Martin^3
1Medical Imaging, University of Arizona, Tucson, Arizona, United States, ²MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, ³Medical Imaging, University of Arizona, Tucson, AZ, United States

This paper describes the clinical implementation of a fast, single-voxel spectroscopy technique for quantifying hepatic lipid fraction and evaluating iron content. The single breath hold technique was performed in consecutive patients, and analyzed retrospectively in comparison to a multi-point 3D Dixon lipid quantification method. The two methods show excellent agreement for quantifying lipid fraction, and estimating iron content.

Christian Kremser¹, Benjamin Henninger¹, Stefan Rauch¹, Heinz Zoller², Wolfgang Vogel², Stephan Kannengiesser³, Xiaodong Zhong⁴, and Werner Jaschke^1
1Dept. of Radiology, Innsbruck Medical University, Innsbruck, Austria, ²Dept. of Internal Medicine, Innsbruck Medical University, Innsbruck, Austria, ³MR Applications Development, Siemens AG Healthcare, Erlangen, Germany, ⁴MR R&D Collaborations, Siemens Medical Solutions, Atlanta, GA, United States

The evaluation of hepatic fat by MR techniques is of increasing interest for clinical routine. The purpose of our study was to compare fat quantification of the liver based on 1H spectroscopy and two different imaging based water-fat separation methods. All methods included correction for T2* bias. For clinical purposes a good correlation between the different fat quantification methods was found.

Harald Kramer^1,2, Mark A Kliewer², Perry J Pickhardt², Diego Hernando², Gunag-Hong Chen², and Scott B Reeder^2,3
1Department of Radiology, Ludwig-Maximilians-University Munich, Munich, Germany, ²Department of Radiology, University of Wisconsin - Madison, Madison, Wisconsin, United States, ³Department of Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States

Accumulation of triglycerides in hepatocytes is the hallmark feature of non-alcoholic fatty liver disease and can lead to inflammation, fibrosis and cirrhosis. Since the accepted diagnostic standard (biopsy) is invasive and suffers from poor sampling variability, there is a need for a comprehensive, accurate and non-invasive quantitative biomarker. We evaluated a proton density fat-fraction chemical-shift based MRI technique, dual-energy CT and US shear-wave velocity in comparison to MR spectroscopy. PDFF-MRI shows excellent correlation with MRS whereas CT Hounsfield-Units and CT fat decomposition showed good and moderate correlation, respectively. US SW did not demonstrate any correlation with MRS.

Jurgen H. Runge¹, Bram F. Coolen¹, Edmond Balidemaj², Ulrich H. Beuers³, Aart J. Nederveen¹, and Jaap Stoker^1
1Radiology, Academic Medical Center, Amsterdam, Netherlands, ²Radiotherapy, Academic Medical Center, Amsterdam, Netherlands, ³Gastroenterology & Hepatology, Academic Medical Center, Amsterdam, Netherlands

Standard mDIXON fat-water imaging can be used to reconstruct quantitative fat fraction maps. However, a non-zero intercept of circa 4% is reported upon in recent literature. We optimized the mDIXON protocol by increasing the TR to reduce T1-weighting and by choosing more echoes with asymmetric TEs for a higher NSA. We investigated in phantoms and patients whether this optimized protocol increased accuracy in comparison to ¹H-MRS. In phantoms, the non-zero intercept was resolved, but not in patients. Differences in T1 values of phantoms and tissue may explain why the issue remained for in vivo measurements.

Ai Leng Liang¹, Catherine D. G. Hines², Li Chun Huang¹, Shian-Jiun Shih¹, Donald S. Williams², Elaine Manigbas³, Brian Henry¹, Jeffrey L. Evelhoch², and Chih-Liang Chin^1
1Translational Medicine Research Centre, MSD, Singapore, Singapore, ²Imaging, Merck & Co. Inc., West Point, Pennsylvania, United States, ³Imaging, Maccine Pte Ltd, Singapore, Singapore

We have established non-human primate (NHP) models of dyslipidemia by chronic feeding (9 mo.) two high-fat diets to male cynomolgus monkeys. Compared to normal diet fed NHPs, on average these animals (n=28) have doubled their total cholesterol, HDL- and LDL-cholesterol, but maintained triglyceride at baseline level. Additionally, their MRI-derived hepatic fat fraction (FF) increased from 2.40.6% to 7.74.5%. However, individual FFs do not correlate well with lipoprotein levels or ratios, probably due to small sample size and narrow data range. Our findings provide insights into lipid metabolism dysfunction in the dyslipidemic model and its potential utility for translational research.

Sunil K. Valaparla^1,2, Goldie R. E. Boone¹, Feng Gao¹, Timothy Q. Duong^1,2, 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

Type 2 diabetes (T2DM) has been associated with excessive fat accumulation in the liver and definitive diagnosis using non-invasive fat estimation methods is essential for early treatment. We measured the liver fat fraction in T2DM subjects using triple-echo GRE MRI and compared with current gold standard 1H-MRS. Bland–Altman plots and regression analysis between methods exhibited excellent concordance and correlation. Triple-echo GRE MRI is fast, accurate, provides excellent concordance and correlation with MRS and can be used to replace time-consuming MRS for longitudinal and large cohort studies.

Benjamin Leporq¹, Simon Auguste Lambert¹, Helene Ratiney², Gaspard D'Assignies^1,3, Maxime Ronot^1,3, Valerie Vilgrain^1,3, Olivier Beuf², and Bernard Van Beers^1,3
1Center for research on inflammation, Université PARIS 7 ; INSERM U1149, Paris, France, ²CREATIS CNRS UMR 5220; INSERM U1044; INSA Lyon; UCBL Lyon 1, Universite de Lyon, Villeurbanne, France, ³Beaujon hospital; Department of radiology, Assistance Publique Hopitaux de Paris, Clichy, France

The aim of our study was to validate a 3.0T MRI method for quantifying triglyceride fatty acid (FA) composition. A 3D spoiled gradient multiple echoes sequence was used to acquire magnitude and phase images. Native phase images were corrected for wrap, zero- and first-order phase to rebuild the real part images. A model built upon a nine component fat 1H MR spectrum was used to derive three FA composition related parameters: the number of double bonds (ndb), the chain length (CL) and the number of methylene interrupted double bond (nmidb). Linear regressions showed a strong agreement between ndb, nmidb quantified with MRI on eight vegetables oils and the theoretical values calculated using oil composition. Measurements performed in the liver, in subcutaneous and visceral adipose tissues were consistent with previously published data.

Venkatesh Mani¹, Sarayu Ramachandran¹, Sylvia Biso¹, Joy Cambe¹, and Zahi A. Fayad^1
1Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States

Here, we present an optimized acquisition and image analysis methodology for automated segmentation of abdominal subcutaneous and visceral fat using a 3D CAIPIRINHA and DIXON based acquisition.

Chao Zou¹, Qian Wan¹, Xin Liu¹, and Yiu-Cho Chung^1
1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China

PSIF is a good alternative to T2-TSE for its speed and good T2 contrast in abdominal imaging at 3T. We propose to apply fat/water decomposition to PSIF for robust fat suppression in abdominal imaging. In consideration of short TR in PSIF for higher SNR, three images with different TEs are acquired in an interleaved way and the TE increment was chosen as 0.57 ms. The phantom and volunteer shows the fat and water images are successfully derived from the PSIF images with three different TEs. T2 weighted PSIF water images are improved in diagnostic quality with robust fat suppression.

Jinnan Wang¹, Holger Eggers², Chun Yuan³, and Peter Börnert^2
1Philips Research North America, Seattle, WA, United States, ²Philips Research Europe, Hamburg, Hamburg, Germany, ³University of Washington, Seattle, WA, United States

Phase sensitive inversion recovery (PSIR) reconstruction is a commonly used technique for myocardial infarction detection. Myocardial fat, however, is a potential source of false positive detections. Direct inclusion of fat saturation in regular PSIR is not straightforward. In this work, a phase-sensitive reconstruction technique is combined with Dixon imaging to achieve phase-sensitive Dixon IR imaging. This technique can provide phase sensitive water and fat images without compromising scan efficiency. In vivo tests demonstrated its feasibility and advantages over regular PSIR in body imaging.

Jong Bum Son¹, Ken-Pin Hwang^1,2, John Madewell³, Ersin Bayram², John Hazle¹, and Jingfei Ma^1
1Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States, ²Global MR Applications and Workflow, GE Healthcare, Houston, TX, United States, ³Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States

Fast spin echo triple-echo Dixon (FTED) acquires one in-phase (IP) and two out-of-phase (OP) images in a single acquisition without interleave. A potential drawback is that echo separation between the three readout gradients is fixed so that the minimum echo spacing of FTED as well as some scan parameters is not flexible. In this work, we propose an extended FTED pulse sequence in which the echo separation between the three readout gradients is mostly determined by the scan parameters. The proposed approach is capable of producing uniformly separated water and fat images with minimum echo spacing and adjustable scan parameters.

Sudhanya Chatterjee¹, Kevin M Johnson², Walter F Block^2,3, and Alan B McMillan^1
1Radiology, University of Wisconsin, Madison, Wisconsin, United States, ²Medical Physics, University of Wisconsin, Madison, Wisconsin, United States, ³Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, United States

Quantitative PET imaging in PET/MR systems requires reliable methods for MR-based attenuation correction. While robust MR methods have been described to reliably distinguish fat and water within soft tissue, current MR methods provide limited sensitivity to lung tissue and bone, both of which exhibit substantially different photon absorption. Ultra short echo time imaging, which otherwise due to a very low SNR is a limiting factor for imaging techniques, has been used in this work to provide a motion-robust MR-based attenuation correction (MRAC) technique to segment MR images into water and fat components of soft tissue, bone, and lung.

Kevin J Sinclair¹, Lanette J Friesen-Waldner¹, Colin M McCurdy¹, Curtis N Wiens², Trevor P Wade^1,3, Barbra de Vrijer⁴, Timothy RH Regnault^4,5, and Charles A McKenzie^1,3
1Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada, ²Department of Radiology, University of Wisconsin, Madison, Wisconsin, United States, ³Robarts Research Institute, University of Western Ontario, London, Ontario, Canada, ⁴Department of Obstetrics and Gynaecology, University of Western Ontario, London, Ontario, Canada, ⁵Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada

The metabolic syndrome is a cluster of morbidities that lead to an increased risk of developing cardiovascular disease. Studies suggest that the propensity to develop the metabolic syndrome can be programmed during fetal development. In this study, adipose tissue distributions in guinea pig fetuses were monitored using water-fat MRI. The fetuses were subjected to 3 different in utero conditions: over-nourishment, under-nourishment, and appropriate nourishment of the fetus. T1- and T2-weighted, as well as IDEAL water-fat images were acquired. Increased total adipose tissue was seen in the over-nourished case, while under-nourished fetuses had decreased total adipose tissue compared to normal.

Terence Jones¹, Narendra Reddy², Sarah Wayte³, Oludolapo Adesanya⁴, Thomas Barber⁵, and Charles Hutchinson^1
1Medical School, University of Warwick, Coventry, West Midlands, United Kingdom, ²Metabolic Health, University Hospitals Coventry & Warwickshire, Coventry, CV2 2DX, United Kingdom, ³Medical Physics, University Hospitals Coventry & Warwickshire, Coventry, CV2 2DX, United Kingdom, ⁴Radiology, University Hospitals Coventry & Warwickshire, Coventry, West Midlands, United Kingdom, ⁵Health Sciences, University of Warwick, Coventry, West Midlands, United Kingdom

Ongoing interest in brown adipose tissue (BAT) has led to research in MRI as a potential tool for identifying and quantifying BAT, which is a necessary precursor to clinical trials evaluating pharmacological agents to stimulate BAT. We conducted a study in which areas of potential BAT were identified visually on Dixon MRI and compared with metabolically BAT on PET-CT using colocalization. Visual identification of BAT underestimates BAT volume, particularly when large levels of BAT are present. Conversely the degree of colocalization increases with increasing BAT volumes. This technique may be useful is evaluating future methods of prospective BAT identification.

Colin M McCurdy¹, Bryan T Addeman¹, Curtis N Wiens², Lanette J Friesen-Waldner^1,3, Trevor P Wade^1,3, Jacqueline K Harris¹, Abraam S Soliman⁴, Kevin J Sinclair¹, and Charles A McKenzie^1,4
1Medical Biophysics, The University of Western Ontario, London, Ontario, Canada, ²Radiology, The University of Wisconsin, Madison, Wisconsin, United States, ³Robarts Research Institute, London, Ontario, Canada, ⁴Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada

Excess Intra-Abdominal Adipose Tissue (IAAT) is predictive of the onset of type-2 diabetes and cardiovascular disease. Evaluating adipose tissue volume in mouse models of disease would allow non-invasive investigation of diet or treatment induced changes in fat distribution. Here we demonstrate the adaptation of an automated method for quantification of human adipose tissue for use in mouse MRI. This method was validated by comparison to manual segmentations of normal and obese mice. Bland-Altman analysis showed differences between manual and automated analysis of (6.7 ± 4.7) mm^3 for subcutaneous adipose tissue and (5.2 ± 3.6) mm^3 for IAAT.

Henry H. Ong^1,2, Corey D. Webb³, Marnie L. Gruen³, Alyssa H. Hasty³, John C. Gore^1,2, and E. Brian Welch^1,2
1Vanderbilt University Institute of Imaging Sciences, Nashville, TN, United States, ²Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States,³Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, United States

In obesity, fat-water MRI (FWMRI) methods provide valuable information on adipose tissue (AT) distribution. AT is known to undergo complex metabolic and endocrine changes in association with chronic inflammation. We investigated the potential for quantitative FWMRI to be sensitive to AT inflammatory changes in an established diet-induced obesity mouse model. We examined T₂^* estimates from the fat-water separation algorithm and observed an increasing shift toward higher T₂^* values in perirenal AT with increasing obesity as compared with normal weight mice. Quantitative FWMRI T₂^* measurement shows potential for longitudinal non-invasive assessment of AT dysfunction in obesity.

Alexey Dimov^1,2, Pascal Spincemaille³, Carlo Salustri³, Tian Liu⁴, Bo Xu^1,2, and Yi Wang^1,2
1Biomedical Engineering, Cornell University, Ithaca, NY, United States, ²Radiology, Weill Cornell Medical College, New York, NY, United States, ³Radiology, Weill Cornell Medical College, NY, United States, ⁴MedimageMetric LLC, NY, United States

The quantification of iron content is traditionally performed by R2* mapping, which is sensitive to imaging parameters and affected by large field inhomogeneity such as near the liver-lung interface. In this abstract, we propose the use of a breath-hold 3D spiral multi-echo flow compensated sequence combined with an adaptive fat-water separation method to obtain liver iron content based on magnetic susceptibility.

Diego Hernando¹, Shane A. Wells², Karl K. Vigen¹, and Scott B. Reeder^1,3
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, ²Radiology, University of Virginia, Charlottesville, VA, United States, ³Medicine, University of Wisconsin-Madison, Madison, WI, United States

Previous studies have shown that R2* increases in normal liver after contrast administration. In this work, we investigated the relationship between patients’ clinical data, including body mass index (BMI) and blood analysis results, and R2* measurement, performed before and after administration of gadoxetic acid. A lack of increase of R2* after contrast administration was correlated with elevated values of both total bilirubin and MELD scores, which are measures of liver function and severity of chronic liver disease.

Xiaodong Chen^1,2, Hui Zhang³, Xihai Zhao³, Huailing Zhang⁴, Biling Liang⁵, and Hua Guo^3
1Sun Yat-Sen Memorial Hospital, Guangzhou, Guangdong, China, ²Guangdong Medical College, Guangdong, China, ³Biomedical Engineering&Center for Biomedical Imaging research,School of Medicine,Tsinghua University, Beijing, China, ⁴School of Information Engineering, Guangdong Medical College, Guangdong, China, ⁵Sun Yat-Sen Memorial Hospital, Guangdong, China

Cardiac failure is the main causes of death in patients with thalassemia major 1,2. But its diagnosis is often hysteretic in clinical practice, which probably in consequence of the unpredictability of cardiac iron deposition as well as the lag of appearance of symptoms, Thus, it is vital to monitor the cardiac iron level even in asymptomatic patients. Hepatic iron concentration has been widely used as the indicator of this disease. However, it lacks extensive investigation about the relationship between hepatic iron overload and myocardium iron overload, especially when the liver has severe deposition.

Anna Osiak¹, Krzysztof Jasinski¹, Pawel T. Jochym², Edyta Maslak³, and Tomasz Skorka^1
1Department of Magnetic Resonance Imaging, Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland, ²Department of Materials Research by Computers, Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland, ³Department of Endothelium Experimental Pharmacology, Jagiellonian Center for Experimental Therapeutics (JCET), Kraków, Poland

The objective was to assess cardiac-induced liver deformation in murine model of non-alcoholic fatty liver disease (NAFLD) using MR Tagging. Control and NAFLD mice were examined and liver tissue displacements Disp, E1 and E2 principal strains were computed within 7 regions and normalized to maximum heart declination. In NAFLD the tissue compression increased, maximum Disp and E1 were preserved, but the deformation were propagated deeper in the organ compared to controls, what may reflect increased fat deposition at non-fibrotic stage of pathology. Good consistency of the results suggests the routine may be helpful for evaluation of fat deposition degree.

Jun Chen¹, Kevin Glaser¹, Meng Yin¹, Jayant Talwalkar¹, Phillip Rossman¹, Sudhakar Venkatesh¹, and Richard Ehman^1
1Mayo Clinic, Rochester, MN, United States

Hepatic MR Elastography (MRE) is an accurate noninvasive method for detecting liver fibrosis. Conventional drivers for hepatic MRE are usually rigid, but human bodies are soft and contoured. Therefore, the mechanical coupling between rigid drivers and human body is often not optimal, resulting in potential issues such as wave interferences in the liver. Previous developed hepatic flexible driver was optimized in this study for higher efficiency. Patients with a large range of liver fibrosis stage underwent MRE with both the flexible and rigid drivers. The mean difference was 0.11kPa, indicating that both drivers are equivalent for measuring liver stiffness.

Mikael F. Forsgren^1,2, Bengt Norén^3,4, Johan Kihlberg^2,3, Olof Dahlqvist Leinhard^2,3, Stergios Kechagias⁵, and Peter Lundberg^3,6
1Wolfram MathCore AB, Linköping, Sweden, and Center for Medical Image Science and Visualization(CMIV), Linköping University, Linköping, Sweden, ²Dept. of Medical and Health Sciences, Linköping University, Dept. of Radiation Physics, UHL County Council of Östergötland, Linköping, Sweden, ³Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden, ⁴Dept. of Medical and Health Sciences, Linköping University, Linköping, Sweden, ⁵Dept. of Medical and Health Sciences, Linköping University, Dept. of Gastroenterology and Hepatology, UHL County Council of Östergötland, Linköping, Sweden, ⁶Dept. of Medical and Health Sciences, Linköping University, Depts. of Radiation Physics and Radiology, UHL County Council of Östergötland, Linköping, Sweden

Fibrosis may be reversible in humans, thus there is a great need for the introduction of noninvasive methods in order to monitor fibrosis development. MRE seems to be very promising towards this end. However, we need to verify that different techniques provide comparable results for a wide spread clinic introduction. We have compared 2D and 3D MRE techniques using two different transducer technologies. We examined 7 patients in a single day with a very short time delay (10 min). Our results show that it is possible to obtain comparable estimate of stiffness/elasticity in the liver using different techniques.

Alexander D Cohen¹, Mark D Hohenwalter², and Kathleen M Schmainda^1,2
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, ²Radiology, Medical College of Wisconsin, Milwaukee, WI, United States

Magnetic Resonance Elastography (MRE) has gained prominence for its ability to stage liver fibrosis. MRE measures the propagation of acoustic shear waves, generated by a passive driver, through liver tissue. MRE gives estimates of liver stiffness, which have directly correlated with fibrosis grade in preliminary studies. MRE repeatability was assessed in a cohort of normal volunteers and cirrhotic patients imaged twice in one scanning session. Repeatability was excellent for both the volunteers and cirrhotic patients, and indicate changes must be larger than ~10% to be significant for longitudinal studies and ~10-30% to be significant for between group studies.

Karen Buch¹, Baojun Li², Hei Shun Yu², Brian Tischler³, Naznin Daginawala³, and Stephan Anderson^4
1Radiology, Boston University Medical Center, Boston, MA, United States, ²Boston University Medical Center, Boston, United States, ³Boston University Medical Center, MA, United States, ⁴Radiology, Boston University Medical Center, Boston, United States

The purpose of this study was to evaluate the accuracy of texture analysis applied to T2-weighted images to assess hepatic fibrosis using a linear discriminant analysis. A total of 27 patients with varying grades of biopsy-proven hepatic fibrosis were analyzed with a sensitivity of up to 90% and specificity of 88% for GLCM entropy versus energy texture parameters. The development of accurate, non-invasive methods for the assessment and staging of liver fibrosis is crucial given a growing global impact of chronic liver disease and fibrosis. The application of texture analysis tools using T2-weighted images, possibly as part of a multi-parametric approach, affords the possibility of developing an accurate, noninvasive assessment of hepatic fibrosis.

Benjamin LEPORQ¹, Frank Pilleul^2,3, Jerome Dumortier⁴, Olivier Guillaud⁴, Thibaud Lefort⁵, Pierre-Jean Valette⁵, and Olivier Beuf^2
1Center for research on inflammation, Université PARIS 7 ; INSERM U1149, Paris, France, ²CREATIS CNRS UMR 5220; INSERM U1044; INSA Lyon; UCBL Lyon 1, Universite de Lyon, Villeurbanne, France, ³Centre de lutte contre le cancer, Centre Léon Berard, Lyon, France, ⁴CHU Edouard Herriot; Department of hepatology, Hospices Civils de Lyon, Lyon, France, ⁵CHU Edouard Herriot; Department of gastro-intestinal imaging, Hospices Civils de Lyon, Lyon, France

Our objective was to evaluate T2-corrected IVIM and perfusion imaging using a MR-DCE technique for the distinction between non-advanced and advanced fibrosis in patients with chronic liver diseases. The link between perfusion-related diffusion given by IVIM and quantitative perfusion parameters given by MR-DCE imaging was investigated. Results indicated that the combination of IVIM and MR-DCE imaging do not bring additional information for fibrosis assessment in a large spectra of etiologies. Indeed, perfusion parameters given by MR-DCE imaging alone are relevant to evaluate fibrosis severity. Strong correlation between portal perfusion and perfusion related diffusion coefficient illustrated that IVIM reflects the hemodynamic changes occurring in fibrous damage. Pure molecular diffusion coefficient was affected by the deposition of extracellular matrix components and by fat vesicle suggesting that fat overload can constitute a confounding factor in fibrosis assessment with IVIM. Nevertheless, if fat overload is addressed, IVIM could be a useful injection-free method to distinguish between non-advanced and advanced fibrosis.

Christian T. Farrar¹, Bryan C. Fuchs², Helen Day¹, Nicholas Rotile¹, Danielle DePeralta², Arun Subramaniam³, Kenneth K. Tanabe², and Peter Caravan^1
1Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States, ²Surgical Oncology Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States, ³Sanofi-Aventis, Bridgewater, NJ, United States

There is a critical unmet medical need for non-invasive methods for quantifying liver fibrosis to facilitate early diagnosis, monitor disease progression, and assess response to therapies. Here we demonstrate the use of the collagen-targeted contrast agent EP-3533 to monitor progression of liver fibrosis in a bile duct ligation rat model of liver fibrosis and to assess response to rapamycin therapy.

Hei Shun Yu¹, Baojun Li², Karen Buch², Naznin Daginawala², Brian Tischler², and Stephan Anderson^2
1Boston University Medical Center, Boston, MA, United States, ²Boston University Medical Center, MA, United States

The purpose of this study was to diagnose and stage hepatic fibrosis by performing a texture analysis on post-gadolinium T1 weighted images of the liver parenchyma in the portal venous and equilibrium phases. A MATLAB-based texture analysis program was employed to extract 42 texture features for thirty patients. These texture parameters were analyzed using a linear discriminant analysis to calculate sensitivities and specificities. Findings of this study demosntrate specificities of 72% and 82% discriminating lower from higher grades of hepatic fibrosis on equilibrium and venous phases. The ability to non-invasively assess and quantify the severity of hepatic fibrosis is of diagnostic clinical importance and could potentially minimize invasive biopsy techniques to assess severity of fibrosis.

Yukihisa Takayama¹, Akihiro Nishie², Yoshiki Asayama², Yasuhiro Ushijima², Nobuhiro Fujita², Koichiro Morita², Takashi Yoshiura², Tomoyuki Okuaki³, Makoto Obara³, and Hiroshi Honda^2
1Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ²Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ³Philips Electronics Japan, Tokyo, Japan

We investigated the clinical utility of T1 mapping for the assessment of liver function in patients with chronic liver diseases (CLD) by comparing T1 mapping with patients�f blood serum parameters. T1 value of the liver parenchyma showed significant correlations with serum albumin level, serum total and direct bilirubin levels, and ICG-R15 (the retention rate of indocyanine green 15 min after administration). Especially, T1 values of the liver parenchyma were prolonged with increasing ICG-R15 which indicates a worsening of liver function. T1 relaxation may server as a new biochemical marker of liver function.

Anup Singh¹, Damodar Reddy¹, Mohammad Haris^1,2, Kejia Cai^1,3, Rebecca Wells⁴, Emma E. Furth⁵, K. Rajender Reddy⁴, Hari Hariharan¹, and Ravinder Reddy^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Research Branch, Sidra Medical and Research Center, Doha, Qatar, ³Radiology, University of Illinois at Chicago, Chicago, IL, United States, ⁴Department of Medicine, University of Pennsylvania, Philadelpha, PA, United States, ⁵Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelpha, PA, United States

Objective of current study was to evaluate T1ñ changes in fibrotic human liver. In the current study, T1ñ mapping and analysis of healthy (n=10) and fibrotic (n=10) livers of human subjects on 1.5T clinical scanner were carried out. T1ñ values were significantly higher in fibrotic livers compared to healthy livers. In addition, T1ñ maps of some of the fibrotic liver were more heterogeneous compared to healthy liver. Histogram analysis of T1ñ values was also performed. Results from this preliminary study show the potential of staging liver fibrosis based upon increased T1ñ values in combination with width of histogram and mode values.

Niklas Verloh¹, Claudia Fellner¹, Michael Haimerl¹, Mona Schlabeck¹, Miriam Rabea Kukach², Marcel D. Nickel², Christian Stroszczynski¹, and Philipp Wiggermann^1
1Department of Radiology, University Hospital Regensburg, Regensburg, Germany, ²MR Applications Development, Siemens AG, Healthcare Sector, Erlangen, Germany

The purpose of the study was to assess the ability of volumetric T1 mapping of Gd-EOB-DTPA-enhanced MRI to detect liver cirrhosis. Mean T1 relaxation time of the whole liver parenchyma was used to calculate the reduction rate between plain and enhanced T1 relaxation time. Patients with and without liver cirrhosis were analyzed regarding their reduction rate. The reduction rate of the whole liver was significantly (p ≤ 0.001) lower in patients with liver cirrhosis (35% ± 8%) compared to patients with normal liver function (58% ± 6%). The evaluation of changes in T1 mapping of liver parenchyma in Gd-EOB-DTPA-enhanced images may serve as a useful new, non-invasive technique to quantify liver cirrhosis

Kristina Imeen Ringe¹, Marcel Gutberlet¹, Frank Wacker¹, and Hans-Jürgen Raatschen^1
1Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany

In our prospective study we sought to assess the value of T1-mapping of the liver on gadoxetate-disodium enhanced MRI in patients with PSC. In 40 patients T1-mapping of the whole liver was performed using a 3D GRE-sequence with different flip angles before and after contrast injection. T1 relaxation times in all liver segments were assessed and correlated with liver function tests. T1 relaxation times after contrast injection significantly decreased and correlated with bilirubin, cholinesterase and GOT. Our findings may be useful for dynamic evaluation and follow-up of patients with PSC, as well as for guidance of biopsies.

Mitchell Anthony Cooper^1,2, Pascal Spincemaille², Bo Xu^1,2, Thanh D Nguyen², Martin R. Prince², Michael Elad³, and Yi Wang^1,2
1Biomedical Engineering, Cornell University, Ithaca, New York, United States, ²Radiology, Weill Cornell Medical College, New York, New York, United States, ³Computer Science, Technion - Israel Institute of Technology, Haifa, Israel

High temporal & spatial resolution 4D imaging with large volume coverage is needed to accurately capture organ perfusion. Typically, parallel-imaging reconstruction is done to achieve high frame rate and large volume coverage and results in a loss of signal to noise ratio compared to Nyquist sampling. Furthermore, residual under-sampling artifacts are temporally varying and complicate the quantitative analysis of contrast enhancement curves needed for pharmacokinetic modeling. Here, we propose a method, Patch based Reconstruction Of Undersampled Data or PROUD, that will both improve noise characteristics as well as minimize temporally-varying residual artifacts.

Patrick Zylka¹, Timm Denecke², Dominik Geisel², and Lutz Lüdemann^1
1Klinik und Poliklinik für Strahlentherapie, Universitätsklinikum Essen, Essen, NRW, Germany, ²Klinik für Radiologie, Charité Universitätsmedizin Berlin, Berlin, NRW, Germany

We investigate the possibility to establish a mathematical model which is able to describe liver parameters noninvasive and space-resolved by magnetic resonance imaging (DCE-MRI). We use Gd-EOB-DTPA as contrast agent which is metabolized by healthy hepatocytes whereas the metabolism of damaged cells is strongly suppressed. Determing the rate of metabolism we can compare liver regions to quantify the degree of function loss. After converting voxel signal to relaxation rate (which is proportional to the contrast agent concentration), the data of a chosen liver area is handed to a computer program. The algorithm is based on a two-compartment-model and returns the parameters "overall flow", “mean transit time”, "hepatic input / extraction rate" as well as the compartment volumes.

Hersh Chandarana¹, Benjamin Abiri¹, Byron Gaing¹, Justin Ream¹, Andrew Rosenkrantz¹, Mary Bruno¹, Henry Rusinek¹, and Kai Tobias Block^1
1Radiology, NYU Langone Medical Center, New York, NY, United States

Perfusion weighted imaging (PWI) is not incorporated into routinely abdominal imaging due to the need for additional contrast injection and acquisition time. We have developed a novel acquisition and reconstruction method called GRASP (GRASP: Golden-angle RAdial Sparse Parallel) whereby data is acquired continuously in free-breathing and retrospectively reconstructed with flexible temporal resolution. In this study we have shown that high temporal GRASP reconstruction can be used for PWI to accurately measure kidney function (MR-GFR) as compared with the Cartesian scheme. Furthermore images reconstructed with different temporal resolution from a single acquisition can be used for morphologic evaluation.

Stephen Clark Lenhard¹, Mary Rambo², Ciara Rodgers², Mark Burgert², Lindsey Webster³, Richard Peterson³, Richard Miller³, and Beat Jucker^2
1GlaxoSmithKline, King of Prussia, PA, United States, ²GlaxoSmithKline, PA, United States, ³GlaxoSmithKline, NC, United States

Phospholipidosis (PLD) is a generalized condition in humans and animals characterized by an intracellular accumulation of phospholipids. Using a clinically available liver specific MRI contrast agent (Eovist™;Gadoxetate), hepatobiliary Dynamic Contrast Enhanced MRI (DCE-MRI) was performed to determine if Gadoxetate kinetic changes could be detected with a compound known to induce PLD. Gadoxetate DCE MRI of liver function may be a useful pre-clinical technique to assess hepatic functional consequences of PLD in vivo to support drug development decisions for compounds found to induce PLD.

Jun Isogai¹, Takashi Yamada², Hideo Hatakeyama², Tomoko Miyata³, Kenji Yodo³, Mitsue Miyazaki⁴, and Jun Kaneko^2
1Asahi General Hospital, Asahi, Chiba, Japan, ²Hasuda Hospital, Saitama, Japan, ³Toshiba Medical Systems Corp., Saitama, Japan, ⁴Toshiba Medical Research Institute USA, Inc., IL, United States

Gadlinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) is an alternative hepatobiliary contrast agent that allows combination of dynamic imaging and hepatocyte-specific imaging in a single examination. Several reports have shown that liver tumors can be reliably detected at a high rate using hepatobiliary contrast agents. However, liver hemangiomas are often difficult to distinguish from malignant tumors such as liver metastases and hepatocellular carcinoma. The purpose of this study is to evaluate the usefulness of FSBB technique with Gd-EOB-DTPA in the diagnosis of liver hemangioma.

N. Chatterjee^1,2, R. J. Lewandowski¹, E. Semaan¹, R. Salem¹, R. Ryu¹, K. Sato¹, F. Miller¹, J. C. Carr¹, T. J. Carroll^1,2, and J. D. Collins^1
1Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, ²Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States

Assessing early HCC treatment response following Y-90 RAE is often challenging using conventional CT and MR techniques due to lesion enlargement and heterogeneous peripheral contrast enhancement. Quantitative assessment of the necrotic core (EASL criteria) has shown promise for predicting response to therapy. We present early data evaluating quantitative target lesion perfusion using a radially sampled CE-MRA sequence employing echo-sharing to achieve a 64-fold temporal acceleration and an effective temporal resolution of 45msec. Preliminary results demonstrate that hyperemic effects of regional liver radiation injury raises the absolute target lesion perfusion, requiring normalization to either remote or adjacent liver parenchymal perfusion.

Lorne W Hofstetter¹, Mitchell A Cooper¹, Silvina P Dutruel¹, Mahajabin Rahman¹, Shan Hu¹, Nandadeepa Thimmappa¹, Pascal Spincemaille¹, Yi Wang¹, and Martin R Prince^1
1Radiology, Weill Cornell Medical College, New York, New York, United States

On time-resolved contrast enhanced MRI, a cirrhotic liver tends to enhance less and more slowly than the normal liver. In addition, it is well known that the ratio of arterial to portal blood supply for the liver increases in cirrhosis. In previous approaches, a separate 2D contrast enhanced exam was necessary to sample the liver enhancement curve with high temporal resolution, complicating the integration of this method into clinical practice. We hypothesize that these differences in liver perfusion between normal and cirrhotic liver can be detected using a high frame rate 3D contrast enhanced MRI of the liver obtained with the TRACER method.

Diethard Schmidt^1,2, Andreas Weihusen³, Stephan Clasen², Hans Jörg Rempp², Christina Schraml², Andreas Boss¹, Fritz Schick⁴, Claus D Claussen², and Philippe L Pereira^5
1Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Kanton Zurich, Switzerland, ²Diagnostic and Interventional Radiology, University Hospital Tubingen, Tubingen, Baden-Württemberg, Germany, ³Computing imaging, FraunhoferMevis, Bremen, Germany, ⁴Section for experimental radiology, University Hospital Tubingen, Tubingen, Baden-Württemberg, Germany, ⁵Radiology, SLK-Kliniken, Heilbronn, Baden-Württemberg, Germany

Evaluation of software-assistance and VIBE to optimize MR guided RFA of malignant livertumors

Yilin Liu¹, Zheng Chang², Brian Czito², Mustafa Bashir², Fang-Fang Yin², and Jing Cai^2
1Medical Physics, Duke University, Durham, NC, United States, ²Duke University, NC, United States

In this study, we demonstrated the feasibility of a novel retrospective T2-W 4D-MRI phase and amplitude hybrid sorting method based on HASTE/SSFSE sequence. A result-driven sorting strategy was induced in this technique. The T2-W 4D-MRI technique can be applied on liver, pancreas and many other abdominal regions to exhibit the motion of tumors or critical organs. To validate our technique, 4D-MRI acquisition and reconstruction were tested on a 4D Digital Extended Cardiac-Torso (XCAT) human phantom. 5 healthy volunteers were involved in a human study for this technique. Future evaluation on patients is desired.

Maggie M Fung¹, Lloyd Estkowski², and Ersin Bayram^3
1Global MR Applications and Workflow, GE Healthcare, Jersey City, NJ, United States, ²Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States,³Global MR Applications and Workflow, GE Healthcare, Houston, TX, United States

In body & breast imaging, pulsatility artifacts are often observed due to high aortic flow or cardiac motion. We proposed a slice-selective Motion-sensitized driven-equilibrium (MSDE) technique that enables selective suppression of unwanted flow signal in user specific planes, ideally outside of the main region of interest (ROI). In this study, we have shown the feasibility that slice selective MSDE can be applied outside the main ROI to suppress upstream flow, and the SNR at the main ROI would not be affected while achieving blood suppression effect.

Chuan Huang¹, Yoann Petibon¹, Timothy G Reese², Jinsong Ouyang¹, and Georges El Fakhri^1
1Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States, ²Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States

The respiratory motion of the liver is desired in many clinical applications including respiratory motion compensated image acquisition/reconstruction and image-guided interventions in the liver. Recent advancement in simultaneous MR-PET acquisition enables the possibility to accurately perform MR-assisted liver PET respiratory motion correction using liver motion measured by MR. So far, T1-weighted MRI and tagged MRI have been investigated in the MR-assisted liver motion correction. However, neither T1w MRI nor tagged MRI is optimal for liver respiratory motion measurement in human due to lack of contrast in T1w images in the liver and fading away of tags (T1 of liver is approximately 700ms while respiration cycle is about 5s). In this work, we propose a strategy to obtain the volumetric liver motion field using a navigated slice-by-slice balanced steady-state free precession (Nav-bSSFP) sequence.

Andreas M. Loening¹, Manojkumar Saranathan¹, Nichanan Ruangwattanapaisarn², Daniel V. Litwiller³, Ann Shimakawa³, and Shreyas S. Vasanawala^1
1Dept. of Radiology, Stanford University School of Medicine, Stanford, CA, United States, ²Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand,³GE Healthcare Global MR Applications and Workflow, Rochester, MN, Menlo Park, CA, United States

Single shot fast spin echo acquisition speed is limited by specific absorption rate (SAR). Instead of using a constant low flip angle to reduce SAR, we modulated the refocusing flip angle over the course of the echo train and achieved an at least doubling of imaging speed (2-fold reduction in TR) while preserving image quality. This enabled abdominal scans with fewer, shorter breath-holds and better registered images.

Manojkumar Saranathan¹, Andreas M Loening¹, Daniel V Litwiller², Pauline W Worters³, and Shreyas Vasanawala^1
1Department of Radiology, Stanford University, Stanford, CA, United States, ²Global MR Applications and Workflow, GE Healthcare, Rochester, MN, United States, ³Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States

Single shot T2-weighted imaging methods like SSFSE and HASTE are robust to patient motion but suffer from specific absorption rate (SAR) limitations, reducing their efficiency at 3T due to lengthened TRs. We investigated the use of a variable refocusing flip angle scheme for SSFSE, which enabled significant reduction in TR while preserving image quality. This new sequence called vrfSSFSE was optimized to reduce SAR and maximize SNR for imaging the biliary/pancreatic ducts and the female pelvis and compared to conventional SSFSE imaging.

Puneet Sharma¹, Eugene Duke², Tulshi Bhattacharyya², Stephan Kannengiesser³, Bobby Kalb², and Diego R Martin^2
1Medical Imaging, University of Arizona, Tucson, Arizona, United States, ²Medical Imaging, University of Arizona, Tucson, AZ, United States, ³Siemens Healthcare, Germany

This investigation outlines the use of continuous table movement (CTM) during the acquisition of fat-suppressed T2-weighted single-shot fast spin echo in the abdomen and pelvis. The results show that the CTM acquisition mode allows more uniform fat suppression over large z-FOV, compared to conventional multi-slice, fixed table approach. CTM also affords reduced acquisition times when scanning large anatomic coverage.

Peter Gall¹, Rakesh Kasibhatla², and Heiko Meyer^1
1Siemens AG, Healthcare Sector, Erlangen, Germany, ²Siemens Technology and Services Pvt Ltd, India

Diffusion weighted imaging is an increasingly popular method to detect and characterize dense tissues. The detection of such tissues is often performed based on high b-value images, as they show up as bright spots over a dark background. It has been shown that computed high b-value images as helpful as measured images. In particular it is helpful to interactively define the b-value for the computation. Here a new map is proposed that enables the interaction by simple windowing and can achieve an equivalent image impression to the high b-value images.

Rikiya Yamashita¹, Hiroyoshi Isoda¹, Akihiro Furuta¹, Seiya Kawahara¹, Hironori Shimizu¹, Tsuyoshi Ohno¹, Shotaro Kanao¹, Katsutoshi Murata², David A. Porter³, and Kaori Togashi^1
1Diagnostic Radiology, Kyoto University, Kyoto, Kyoto, Japan, ²Siemens Japan K.K., Tokyo, Japan, ³Siemens A, Healthcare Sector, Erlangen, Germany

The aim of this study was to evaluate the potential ability of readout-segmented echo-planar diffusion-weighted imaging for visualizing the pelvic splanchnic nerve, an important surgical landmark in pelvic nerve-preserving surgery. Eleven healthy male volunteers were examined using this novel technique at 3T, and successful visualization of the targeted nerve was achieved at the rate of 50%. Readout-segmented echo-planar diffusion-weighted imaging may be a promising technique to visualize the pelvic splanchnic nerve preoperatively in clinical settings.

Justin M Ream¹, Christopher Glielmi², Mariana Lazar¹, Naomi Campbell¹, Josef Pfeuffer³, Rainer Schneider³, and Andrew B Rosenkrantz^1
1Radiology, NYU Langone Medical Center, New York, NY, United States, ²Siemens Medical Solutions MR R&D, New York, NY, United States, ³Imaging and Therapy Divison, Siemens AG Healthcare Sector, Erlangen, Germany

While tractography of the prostate gland has previously been done only with the use of an endorectal coil, tractography using a standard pelvic phased array coil is feasible using zoomed EPI acquisition.

Wolfgang Loew¹, Pelin A. Ciris², Wei Wang², Ehud J. Schmidt², Charles Dumoulin¹, Randy O. Giaquinto¹, Clare M. Tempany-Afdhal², and Zion T.H. Tse^3
1Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States, ²Radiology, Brigham and Womens Hospital, Boston, Massachusetts, United States, ³Engineering, The University of Georgia, Athens, Georgia, United States

In this abstract a prostate coil for Magnetic Resonance Elastography (MRE) including Magnetic Resonance Imaging (MRI) and Magnetic Resonance Tracking (MRT) at 3 Tesla is presented. Details of the coil features and their benefits are described. The setup for sheer wave generation is described and tested on a phantom.

Pardeep Mittal¹, Sadhna Nandwana¹, Kelly Cox¹, Kiran K Maddu¹, Juan C Camacho¹, Nima Kokabi¹, Courtney C Moreno¹, and Bobby Kalb^2
1Radiology and Imaging Sciences, Emory Uni School of Medicine, Atlanta, Georgia, United States, ²Diagnostic Radiology, University of Arizona, Tucson, Arizona, United States

Hematospermia (HS) is often times an anxiety provoking idiopathic self limiting condition. Potential etiologies, diagnostic work up, imaging techniques and appearance of associated pathologies will be discussed. MRI plays an important role in diagnostic work up of men with persistent hematospermia due to its superior soft tissue contrast, multiplanar capabilities and ability to resolve small caliber structures e.g. ejaculatory ducts, vasa deferentia and internal architecture of prostate in both young and older patients. Participants will gain an appreciation for the wide variety of conditions encountered in HS on MRI imaging.

Milan Hajek¹, Zuzana Ryznarova^1,2, Filip Jiru¹, Viktor Vik³, Roman Zachoval³, and Monika Dezortova^1
1MR-Unit, Dept. Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic, ²Dept. Radiology, Thomayer Hospital, Prague, Czech Republic, ³Dept. Urology, Thomayer Hospital, Prague, Czech Republic

Age dependence of citrate concentration and its ratio to creatine and cholines in the prostate was studied in healthy volunteers at 1.5T and 3T MR systems using 3D CSI sequence. Coefficient of asymmetry between left and right peripheral zones was calculated. Significant increase in the citrate concentration was found between 20 and 70 years and equation parameters for age dependence of prostate metabolites were determined.

Xiaomeng Zhang^1,2, Ruth Lim^1,2, Arkadiusz Sitek^1,2, Jingsong Ouyang^1,2, Brian Pugmire^1,2, and Georges El Fakhri^1,2
1Massachusetts General Hospital, Boston, MA, United States, ²Harvard Medical School, Boston, MA, United States

We investigate an automatic method of analysis of dynamic MR Urography (MRU) for extraction of distinct physiological compartments.

Florian Lietzmann¹, Philipp Krämer¹, and Lothar R. Schad^1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany

We present an approach to measure the transversal relaxation time T2 to characterize kidney function during a water charge examination. Two healthy volunteers were included in our pilot study. Every subject had to undergo a 10h diet without any food or drink intake prior to the examinations. Data was acquired via a ROI readout in the calculated T2 maps. In conclusion, T2-BOLD-MRI is feasible and in contrast to conventional T2* BOLD-techniques the T2 measurement produce more consistent and reliable results characterizing kidney function during a waterload experiment.

Glen Morrell¹, Jeff L Zhang¹, Josh Kaggie¹, and Vivian S Lee^1
1Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, Utah, United States

We present a prospectively navigated renal BOLD sequence for free breathing full 3D BOLD imaging of the kidney. 3D renal BOLD has several advantages over 2D single slice imaging, including improved SNR, potential correction of T2* errors caused by B0 inhomogeneity, and less subjective sampling of cortex and medulla. Our sequence obtains full 3D renal BOLD data at high spatial resolution with reasonable imaging time.

Wu Jingyun¹ and Wang Xiaoying^2
1Peking University 1st Hospital, Beijing, Beijing, China, ²Peking University 1st Hospital, Beijing, Beijing, Bahamas

the present study is to investigate feasibility of noninvasive quantitative measurements of intrarenal R(2) ' .

Joshua D Kaggie¹, Vivian S Lee¹, and Glen R Morrell^1
1Utah Center for Advanced Imaging Research, Radiology, University of Utah, Salt Lake City, UT, United States

A recent study in diabetic mice suggests a correlation between renal cortical fat content and severity of renal disease. We retrospectively evaluated the fat content of kidneys in 14 human subjects with varying degrees of renal failure ranging from normal renal function to dialysis dependence, based on in- and out-of-phase T1-weighted axial images of the kidneys. Correlation between fat content measured with the in-phase/out-of-phase images and the body mass index (BMI) or estimated glomerular filtration rate (eGFR) was investigated. We find no significant correlation between renal fat content and severity of renal disease in humans with diabetic nephropathy.

Shannon Donnola¹, Lan Lu^1,2, Jane Little³, Katherine Dell⁴, Connie Piccone⁵, and Chris Flask^1,6
1Radiology, Case Western Reserve University, Cleveland, Ohio, United States, ²Urology, Case Western Reserve University, Cleveland, Ohio, United States, ³Hematology and Oncology, University Hosptials-Case Medical Center, Cleveland, Ohio, United States, ⁴Pediatrics, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, United States,⁵Pediatrics, University Hospitals-Case Medical Center, Cleveland, Ohio, United States, ⁶Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States

Chronic kidney disease (CKD) is an important complication in sickle cell disease and begins in childhood. Unfortunately, current clinical measures of kidney function are insensitive to early kidney changes, a time point when therapies could be more effective. In this initial study, we used Arterial Spin Labeling and Diffusion Tensor Imaging techniques to assess kidney changes in pediatric SCD patients in comparison to healthy control subjects. Cortical Apparent Diffusion Coefficients (ADC), medullary Fractional Anisotropy (FA), and cortical perfusion were all significantly reduced in young SCD patients. These quantitative MRI techniques could potentially compliment current clinical assessments of kidney function.

Guangyu Wu¹ and Jianrong Xu^1
1Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, »ÆÆÖÇø, ÉϺ£ÊÐ, China

This study was to evaluate the usefulness of magnetic resonance(MR) R2* mapping in assessing response of treatment in patients with pulmonary metastatic renal cell carcinoma receiving anti-angiogenic targeted therapy.

Kazuhiro Shimizu¹, Nobuyuki Kosaka¹, Yasuhiro Fujiwara¹, Tsuyoshi Matsuda², Tatsuya Yamamoto¹, Tatsuro Tsuchida¹, Katsuki Tsuchiyama³, Nobuyuki Oyama³, and Hirohiko Kimura^1
1Department of Radiology, University of Fukui, Eiheiji, Fukui, Japan, ²Global MR Applications and Workflow, GE Healthcare Japan, Hino, Tokyo, Japan, ³Department of Urology, University of Fukui, Eiheiji, Fukui, Japan

We evaluated the feasibility of pulsed continuous arterial spin labeling (pcASL) MRI with multiple post-label-delay (PLD) acquisition for measuring arterial transit time (ATT)-corrected renal blood flow (ATC-RBF) in healthy volunteers. Significant differences were seen between younger and older groups in ATC-RBF and ATT, and kidney volume-corrected ATC-RBF (ATC-cRBF) correlated significantly with effective renal plasma flow (ERPF), as measured by 99mTc-MAG3 scintigraphy. However, the only moderate correlation between ATC-cRBF and ERPF suggests that further technical development may be required for RBF quantification by pcASL MRI.

Iris Friedli¹, Lindsey A Crowe¹, Magalie Viallon¹, Sophie de Seigneux², and Jean-Paul Vallée^1
1Radiology, Geneva University Hospital, Geneva, Switzerland, ²Nephrology, Geneva University Hospital, Geneva, Switzerland

The use of diffusion-weighted imaging for renal study is challenging due to limited spatial resolution, image blurring and severe geometric distortions at tissue-air, tissue-intestine interfaces. We report on the first comparison in kidney between a ‘readout segmentation of long variable echo-trains’ (Resolve) strategy with different versions of single-shot SE-EPI. A key result is the benefit of Resolve to drastically improve both the diffusion image quality by reducing susceptibility artifacts and the measurement of the Apparent Diffusion Coefficient (ADC) of the cortex and medulla.

Florian Rousset^1,2, Clément Vachet¹, Christopher Conlin³, Marta Heilbrun³, Jeff L. Zhang³, Vivian S. Lee³, and Guido Gerig^1
1Scientific Computing and Imaging Institute, Salt Lake City, Utah, United States, ²CPE Lyon, Lyon, France, ³Utah Center for Advanced Imaging Research, Salt Lake City, Utah, United States

The glomerular filtration rate (GFR) is a crucial measurement for tailoring drug regimens and monitoring patients with liver cirrhosis via renography. Dynamic MRI presents sought contrast changes but also breathing motion, which we correct via kidney detection. We have developed a novel software offering an integrated user-friendly tool to register dynamic kidney series, select regions of interest, visualize time-varying concentration, and calculate GFR values. With 98.69% success rate in correction for motion of image frames, our tool runs on different pltaforms and provides robust registration while significantly reducing processing time and giving accurate GFR values compared to an existing software.

Sophie van Baalen¹, Alexander Leemans², Pieter Dik¹, Bennie ten Haken³, and Martijn Froeling^2
1Pediatric Urology, University Medical Centre Utrecht/ WKZ, Utrecht, Netherlands, ²Imaging science institute, University Medical Centre Utrecht, Utrecht, Netherlands,³Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, Netherlands

For imaging of kidney pathologies, the use of endogenous contrast is important, because contrast agents can further damage renal function. MRI-DTI and IVIM are promising imaging techniques for kidney imaging because they enable to measure the extent and direction of water diffusion and the perfusion fraction, respectively. In this study we used MRI-DTI and IVIM to visualize the microstructural properties of kidney tissues. With MRI-DTI and tractography, the radially orientation of the tubules and vascular network in the renal medulla is reflected by radially oriented tracts, originating in the cortex and convolving in multiple papillae. With IVIM, blood perfusion and urine diffusion fractions can be visualized for different kidney tissues.

Magdalena Sokolska¹, David Thomas², Alan Bainbridge¹, Xavier Golay², Stuart Taylor³, Shonit Punwani³, and Douglas Pendse^3
1UCH Medical Physics and Bioengineering, London, London, United Kingdom, ²UCL Institute of Neurology, London, London, United Kingdom, ³Centre for Medical Imaging, UCL, London, United Kingdom

Renal diseases are associated with abnormalities in renal perfusion. Furthermore, characterisation of focal renal lesions such as carcinomas is dependent on the assessment of renal vascularity. Traditionally renal perfusion imaging has relied on contrast agents, which are nephrotoxic. Arterial Spin Labelling (ASL) allows for the assessment renal perfusion without contrast agent injection. Furthermore ASL offers quantification of renal blood flow (RBF) which may be a useful imaging biomarker. This work aims to assess repeatability of pseudo-continuous ASL1 (pCASL) in healthy volunteers.

Justin M Ream¹, Byron Gaing¹, Thais C Mussi², and Andrew B Rosenkrantz^1
1Radiology, NYU Langone Medical Center, New York, NY, United States, ²Hospital Israelita Albert Einstein, Sao Paolo, Brazil

Chemical shift MRI has an integral role in detecting intracellular lipid in adrenal adenomas, although most published data has utilized 1.5 Tesla imaging. The purpose of this study is to compare chemical shift imaging at 1.5T and 3T imaging within the same set of adrenal lesions in order to perform a direct intra-individual comparison of 1.5T and 3T imaging in diagnosing adrenal adenomas.

Christopher C. Conlin¹, Jeff L. Zhang¹, Marta E. Heilbrun¹, Kristi Carlston¹, Daniel Kim¹, Kathryn A. Morton¹, and Vivian S. Lee^1
1Department of Radiology, University of Utah, Salt Lake City, Utah, United States

This study compares long and short inversion times (TIs) for measuring arterial input functions (AIFs) from saturation recovery images in the estimation of glomerular filtration rate (GFR) from low dose Gd-enhanced MR renography. Long TIs may result in saturated signal and therefore an inaccurate estimate of Gd concentration which is required for GFR calculation. Short TIs may suffer from low SNR. By comparing GFR estimates obtained at short and long TIs to reference measurements from 99mTc-DTPA clearance, it was found that relatively long TIs should be used to avoid accumulation of AIF error into the estimated GFR.

Adam M Winchell^1,2, Atmaram Pai Panandiker¹, Ruitian Song¹, Ralf B Loeffler¹, and Claudia M Hillenbrand^1
1Radiological Sciences, St. Jude Children’s Research Hospital, Memphis, TN, United States, ²Biomedical Engineering, University of Memphis, Memphis, TN, United States

In this study, we measured respiratory induced kidney motion in young children with abdominal neuroblastoma using both 4D-CT and real-time MRI to evaluate tracking accuracy. Real-time MRI provides a more desirable tissue contrast of the kidney and had about two times higher spatial resolution in the superior/inferior direction compared to 4D-CT which enabled superior demarcation of organ boundaries, anatomical tracking, and improved accuracy.

Katherine L. Wright¹, Yong Chen², Mark A. Griswold^1,2, Nicole Seiberlich¹, and Vikas Gulani^1,2
1Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States, ²Radiology, Case Western Reserve University, Cleveland, Ohio, United States

This work demonstrates 3D quantitative renal DCE MRI using half and quarter doses (by weight) of a gadolinium based contrast agent and no breath-holds. Data are acquired with a highly accelerated stack-of-stars acquisition, reconstructed using 3D through-time radial GRAPPA, and registered to remove respiratory motion. This exam provides 3D quantification of perfusion, filtration, and mean transit times at clinically relevant spatial resolutions using very low doses of contrast agent.

Haoran Sun¹, Huanhuan Wu¹, and Ziheng Zhang^2
1Radiology, Tianjin Medical University Hospital, Tianjin, Tianjin, China, ²MR Research China, GE Healthcare, Shanghai, Shanghai, China

Intravoxel incoherent motion (IVIM) DWI has recently shown potential to assess functional changes of renal fibrosis. From the findings through multi-b DW-MRI measurements on cisplatin induced rodent renal fibrosis models, the temporal variation of ADC values behaved as a weight of the true diffusion and pseudo-diffusion. The biomarkers resulted from mono-exponential model exhibited a dual phase temporal variation, while those from bi-exponential model remained a single tendency of variation. According to the histopathological observation that the worsening of renal fibrosis with time, the bi-exponential model might be a better choice for an accurate indication of the evolution of renal fibrosis.

Jorge Chacón-Caldera¹, Philipp Krämer¹, Sebastian Domsch¹, Stefania Geraci², Norbert Gretz², and Lothar R Schad^1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, ²Medical Research Center, Heidelberg University, Mannheim, Germany

The number of glomeruli in kidneys is associated with kidney diseases. There is interest to discover if glomerular quantification in humans is possible. Currently, glomerular imaging with MRI is achieved using in vitro samples in preclinical systems with main magnetic fields of minimum 7T. This work presents the first ever glomerular images acquired with a clinical scanner at 3T. We used two cationazed-ferritin labeled rat kidneys and a Siemens Magnetom to demonstrate that currently available clinical scanners are capable of performing glomerular imaging. The parameters were also used to assess the current standpoint towards future human kidney measurements.

Andreas Pohlmann¹, Jan Hentschel¹, Karen Arakelyan¹, Mandy Fechner², Uwe Hoff², Gordana Bubalo², Kathleen Cantow³, Sonia Waiczies¹, Duska Dragun², Bert Flemming³, Erdmann Seeliger³, and Thoralf Niendorf^1
1Berlin Ultrahigh Field Facility, Max Delbrueck Center for Moleculare Medicine, Berlin, Germany, ²Nephrology and Intensive Care Medicine, Campus Virchow-Klinikum and Center for Cardiovascular Research, Charite-Universitaetsmedizin Berlin, Berlin, Germany, ³Institute of Physiology and Center for Cardiovascular Research, Charité Medical Faculty, Berlin, Germany

Imbalance between renal tissue oxygen demand and supply is a pivotal element in the pathophysiologic cascade of ischema/reperfusion injury. Parametric mapping of renal T2*, which is known to be blood oxygenation level dependent, to monitor I/R in rats if feasible, however, comparison of absolute renal T2* is barely feasible, because absolute values depend on magnetic field strength, B0 homogeneity, etc. By applying image heterogeneity analysis by 2D Minkowski functionals to renal T2* data we investigated whether renal T2* heterogeneity analysis allows a differentiation between healthy naïve kidneys, ischemic kidneys, and kidneys during subsequent reperfusion.

Jorge Chacón-Caldera¹, Raffi Kalayciyan¹, and Lothar R Schad^1
1Computer Assisted Clinical Medicine, University of Heidelberg, Mannheim, Germany

Imaging whole kidney volumes to visualize glomeruli with MRI requires long acquisition times. Wrong parameters selection can reduce or even impede the visualization of the glomeruil. In this work we present quick measurements of effective transverse relaxation time (T2*) in the kidney cortex and cationized-ferritin labeled glomeruli at 9.4T in mouse kidneys. The contrast between them was also calculated for the whole range of measured echo times. These measurements can be easily extrapolated and/or replicated in other systems and field strengths to facilitate the glomerular imaging, reduce the scanning times and improve the accuracy and efficiency of possible glomerular quantifications.

Xiaodong Zhang¹, Yue Mi², Jing Wang³, Jingyun Wu¹, Kai Zhao¹, Jian Luo¹, Xuedong Yang¹, Xiaoying Wang^1,4, Jue Zhang⁴, and Hongyu An^5
1Department of Radiology, Peking University First Hospital, Beijing, Beijing, China, ²Department of Urology, Peking University First Hospital, Beijing, Beijing, China, ³School of physics, Peking University, Beijing, Beijing, China, ⁴Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, Beijing, China, ⁵Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States

Quantitative measurement of renal oxygenation is of central importance in understanding and treating renal diseases and oxygen extraction fraction (OEF) can provide a valid criterion for evaluation the tissue oxygen metabolism under both normal and disease states. According to the Yablonskiy and Haacke’s biophysical analytical model, the intra-renal OEF can be estimated using a multi-echo gradient and spin echo (MEGSE) sequence. In this study, we will demonstrate the ability to obtain quantitative estimates of intra-renal OEF noninvasively in normal and unilateral renal artery stenosis rabbits of the Multi-Echo Gradient and Spin Echo (MEGSE).

Andreas Pohlmann¹, Jan Hentschel¹, Karen Arakelyan¹, Stefanie Kox¹, Sonia Waiczies¹, Bert Flemming², Erdmann Seeliger², and Thoralf Niendorf^1
1Berlin Ultrahigh Field Facility, Max Delbrueck Center for Moleculare Medicine, Berlin, Germany, ²Institute of Physiology and Center for Cardiovascular Research, Charité Medical Faculty, Berlin, Germany

Acute kidney injuries (AKI) of various origins share one common feature: imbalance between local tissue oxygen delivery and demand. Changes in tissue pO2 and T2* may be closely related, however, their link could be influenced by variations in blood volume fraction. We hypothesized that monitoring of RBV could provide evidence for a significant RBV reduction during aortic occlusion, and hence for the relevance of RBV when interpreting renal T2*. To test our hypothesis we established RBV estimation with ferumoxytol at 9.4 Tesla in rats and compared the effects of renal arterio-venous occlusion with suprarenal aortic occlusion while monitoring renal T2*.

Florian Lietzmann¹, Christina Hopfgarten¹, Jorge Chacón-Caldera¹, Stefania Geraci², and Lothar R. Schad^1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, ²Medical Research Center, Heidelberg University, Mannheim, Germany

Renal imaging using MRI is crucial but not available to many institutions because until now it relied in high-end systems working at high or ultra high field strengths. As an alternative, a low-field portable MR-system which can achieve similar resolutions like a small animal system can provide images with the demanded resolution. Purpose of this work is an initial comparison of the image quality of an acquisition with the low field system to the state of the art methods. In all images a distinction between the different tissue compartments is possible. In conclusion, high resolution imaging of the kidney need not necessarily be performed on high field systems. The portable MR system reaches a sufficient resolution for the distinction of different renal compartments as well as the identification of an inner structure of the renal cortex.

Andreas Pohlmann¹, Jan Hentschel¹, Uwe Hoff², Gordana Bubalo², Mandy Fechner², Maximilian Blum³, Ye Zhu², Karen Arakelyan^1,4, Erdmann Seeliger⁴, Bert Flemming⁴, Dennis Gurgen², Wolfgang Schneider³, Michael Rothe⁵, Vijaya L Manthati⁶, John R Falck⁶, Wolf-Hagen Schunck³, Duska Dragun², and Thoralf Niendorf^1
1Berlin Ultrahigh Field Facility, Max Delbrueck Center for Moleculare Medicine, Berlin, Germany, ²Nephrology and Intensive Care Medicine, Campus Virchow-Klinikum and Center for Cardiovascular Research, Charite-Universitaetsmedizin Berlin, Berlin, Germany, ³Experimental and Clinical Research Center, Charite Medical Faculty and the Max Delbrueck Center for Molecular Medicine, Berlin, Germany, ⁴Institute of Physiology and Center for Cardiovascular Research, Charité Medical Faculty, Berlin, Germany,⁵Lipidomix GmbH, Berlin, Germany, ⁶Biochemistry Department, UT Southwestern, Dallas, TX, United States

Current therapeutic options for treating acute kidney injury (AKI) are disappointing and hence the need for establishing druggable targets. Imbalances in cytochrome P450 (CYP)-dependent eicosanoid formation may play a central role in AKI. Imbalance between renal oxygen demand and supply is considered to be the initiating step in the pathophysiologic cascade of events. In this study we investigated whether administration of an epoxyeicosatrienoic acid (EET) agonist improves renal reoxygenation during the initial 2 h reperfusion phase. Parametric mapping of renal T2* demonstrated improved renal re-oxygenation after EET treatment. EET agonists may provide novel therapeutic options for prevention of ischemic AKI.

Andreas Pohlmann¹, Adrian Schreiber², Min-Chi Ku³, Helmar Waiczies⁴, Stefanie Kox¹, Ralph Kettritz², Sonia Waiczies¹, and Thoralf Niendorf^1,5
1Berlin Ultrahigh Field Facility, Max Delbrueck Center for Moleculare Medicine, Berlin, Germany, ²Clinic for Nephrology and Intensive Care Medicine, Campus Virchow, Charité Medical Faculty, Berlin, Germany, ³Berlin Ultrahigh Field Facility, Max Delbrueck Center for Molecular Medicine, Berlin, Germany, ⁴MRI.TOOLS GmbH, Berlin, Germany, ⁵Experimental and Clinical Research Center, Charite Medical Faculty and the Max Delbrueck Center for Molecular Medicine, Berlin, Germany

Anti-neutrophil cytoplasmic antibodies (ANCA) are responsible for the development of small vessel vasculitis. Currently, diagnosis of the initial inflammation and its recurrences relies on kidney biopsies, hence, the clinical need for non-invasive methods. We have employed multi-modal fluorescently (DiI) and 19F labeled nanoparticles to identify specific inflammatory cell populations tested the hypothesis that 19F MRI after in-vivo 19F-labeling of monocytes and neutrophils allows non-invasive detection of ANCA-induced renal inflammation. Our data suggest that 19F-MRI may represent a novel non-invasive method for the assessment of renal inflammation in mouse models with the potential of translation into a clinical tool for the diagnosis of glomerulonephritis in patients.

Galen D Reed¹, Cornelius von Morze¹, Bertram L Koelsch¹, Myriam M Chaumeil¹, Alan S Verkman², Sabrina M Ronen¹, Robert A Bok¹, Jeff M Sands³, Peder E Larson¹, Jan Henrik Ardenkjaer-Larsen⁴, John Kurhanewicz¹, and Daniel B Vigneron^1
1Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California, United States, ²Nephrology, University of California San Francisco, San Francisco, California, United States, ³Department of Medicine, Renal Division, Emory University, Atlanta, Georgia, United States, ⁴Electrical Engineering, Technical University of Denmark, Lyngby, Denmark

Urea is a key osmolyte that plays a crucial role in kidney function. In this study, we present a hyperpolarized ¹³C MRI method for imaging urea within the renal tubules and collecting system at 1.2 mm isotropic resolution. This method utilizes the increased urea T₂ from ¹⁵N labeling combined with specialized 3D SSFP acquisition and the very large ¹³C urea T₂ contrast observed between the kidney and vasculature. Relaxometry experiments revealed this long-T₂ signal reports on urea that has passed through the glomerulus, thus enabling renal urea filtration as a source of image contrast.

David J Niles¹, Jeremy W Gordon¹, and Sean B Fain^1,2
1Medical Physics, University of Wisconsin, Madison, WI, United States, ²Radiology, University of Wisconsin, Madison, WI, United States

Anesthesia produces several physiologic effects in the kidney, including changes of blood flow, glomerular filtration, and sodium excretion. Because R₂* is influenced by hemodynamic parameters and oxygenation, its value may differ depending on the choice and dosage of anesthetic agent used during imaging. We measured renal R₂* in mice anesthetized with five common anesthetics and observed strong dependence of R₂* on the choice of agent. Differences in R₂* between inhaled and injected agents was not explained by differences in inspired oxygen fraction. We conclude that the effects of anesthetic agent should be considered when designing and evaluating BOLD MRI studies.

Yoshichika Yoshioka^1,2, Ting Chen¹, Yuki Mori^1,2, Zhenyu Cheng¹, Yuuto Kashiwagi¹, Masaki Fukunaga^2,3, Ikuhiro Kida^1,2, Yoshiyuki Tago⁴, Shinichi Yoshida⁴, and Kohji Ohno^5
1Immunology Frontier Research Center (IFReC), Osaka University, Suita, Osaka, Japan, ²Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT) and Osaka University, Suita, Osaka, Japan, ³1Immunology Frontier Research Center (IFReC), Osaka University, Suita, Osaka, Japan, ⁴Frontier Biochemical and Medical Research Laboratories, Kaneka Corporation, Takasago, Hyogo, Japan, ⁵Institute for Chemical Research, Kyoto University, Uji, Kyoto, Japan

The biodistribution pattern of newly synthesized magnetic nano particles was investigated in mice. The particles are taken little by Kupffer cells and peripheral macrophages and have the long half-life in mouse blood circulation. The particles showed the marked distribution pattern especially in the mouse kidney. The particles retained much in the renal cortex and in the boundaries between cortex and medulla and between outer medulla and inner medulla. The dark round spots in the renal cortex were confirmed as renal corpuscles. These distribution patterns could be used as a measure of renal functions.

Edwin Baldelomar¹, Scott Beeman², Luise Cullen-McEwen³, Jennifer R Charlton⁴, John F. Bertram³, and Kevin M. Bennett^5
1Department of Physics, University of Hawai'i at Manoa, Honolulu, Hawaii, United States, ²Radiology, Washington University School of Medicine, St Louis, Missouri, United States, ³Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia, ⁴University of Virginia Medical Center, Charlottesville, Virginia, United States, ⁵Department of Biology, University of Hawai'i at Manoa, Honolulu, Hawaii, United States

MRI has previously been shown to be a viable tool to establish nephron endowment in intact kidneys using super paramagnetic, glomerulus specific, cationic ferritin (CF). Along with nephron number, glomerular size may also be measured be with MRI. This work takes into account susceptibility of super paramagnetic CF labeling in 3D T2* gradient echo MRI to correct volume measurements from MRI to establish accurate, non-invasive, kidney morphology measurements in mice.

Katja Hueper^1,2, Song Rong³, Marcel Gutberlet^1,2, Matti Peperhove¹, Susanne Tewes¹, Amelie Barrmeyer¹, Martin Meier⁴, Sibylle von Vietinghoff³, Michael Mengel⁵, Hermann Haller³, Frank Wacker^1,2, Dagmar Hartung^1,2, and Faikah Gueler^3
1Radiology, Hannover Medical School, Hannover, Germany, ²REBIRTH Cluster of Excellence, Hannover Medical School, Hannover, Germany, ³Nephrology, Hannover Medical School, Hannover, Germany, ⁴Institute of Animal Science, Hannover Medical School, Hannover, Germany, ⁵Alberta Transplant Applied Genomics Centre, University of Alberta, Edmonton, Alberta, Canada

We investigated whether multiparametric functional MRI allows evaluation of renal allograft rejection in mice. An acute rejection was induced by allogenic kidney transplantation; animals after isogenic transplantation were used as controls. Three weeks after transplantation renal perfusion (ASL), T1-/ T2-relaxation times and ADC-values were determined using a 7T-scanner. Animals after allogenic transplantation developed an acute T-cell-mediated rejection. In these animals, renal perfusion impairment was stronger, T1- and T2-values were higher and ADC was lower compared to animals after isogenic transplantation. Functional MRI-parameters significantly correlated with the extent of T-cell-infiltrates. Thus, functional MRI may improve non-invasive diagnosis of renal allograft rejection.

Septian Hartono^1,2, Tong San Koh¹, In Chin Song³, Lin Zheng³, Wing Sum Lee³, Laurent Martarello⁴, and Choon Hua Thng^1
1National Cancer Centre Singapore, Singapore, Singapore, Singapore, ²Nanyang Technological University, Singapore, Singapore, Singapore, ³SingHealth Experimental Medicine Centre, Singapore, Singapore, ⁴Roche Translational Medicine Hub, Singapore, Singapore

We aim to determine if DCE-MRI and DWI can detect renal interstitial fibrosis in mice. Renal fibrosis is induced by unilateral ureteric obstruction (UUO) with survival surgery. Six mice were scanned before the UUO procedure dan one week after the UUO. Renal fibrosis is quantified by amount of fibrosis as measured by Sirius Red stain. There is a drop of ADC as derived from DWI and renal parenchymal mean transit time (PMTT) as derived from DCE-MRI in the cortices of the ligated kidneys. PMTT correlated significantly with % of Sirius Red, signifying potentials of using DCE-MRI as biomarker of renal fibrosis.

Oliviero L Gobbo¹, Andrew J Fagan², Colin Ryan³, Deirdre Edge⁴, Christine Shortt⁴, Marek Radomski³, Adriele Prina-Mello⁵, Farouk Markos⁴, and Yuri Volkov^5
1School of Pharmacy and Pharmaceutical Sciences and TCIN, Trinity College Dublin, Dublin, Leinster, Ireland, ²Centre for Advanced Medical Imaging (CAMI), St James’s Hospital / Trinity College Dublin, Dublin, Ireland, ³School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Dublin, Ireland, ⁴Physiology Department, University College Cork, Cork, Ireland, ⁵School of Medicine, Trinity College Dublin, Dublin, Ireland

MULTIFUN consortium's current goal is to develop and validate multifunctional SPION for the early detection and treatment of breast and pancreatic cancer while reducing side effects for patients compared to conventional treatment with anti-cancer drugs. This joint therapeutic and diagnostic property has been called “theranostic”. Our study establishes an MRI protocol for the quantification of SPIONs in ex-vivo pig organs (i.e. kidneys) which can potentially be used in preclinical cancer research and in translational medicine.

jie zhang¹, huadan xue², zhengyu jin², and ziheng zhang^3
1PUMCH, Beijing, Beijing, China, ²PUMCH, Beijing, China, ³MR Research China, GE Healthcare, Beijing, China

In the study the capability of using the ADC values depicting pseudo-perfusion and diffusion respectively resulted from a bi-exponential model to discriminate cervical squamous cell cancer and cervical adenocarcinoma, which feature similar clinical symptoms, in a multi-b diffusion weighted MR imaging measurement. A smaller ADCslow value of cervical squamous cell carcinoma and larger ADCfast and Ffast values of cervical squamous cell carcinoma respectively vs. counter-part were found. To differentiation the grades of both the cervical squamous cell carcinoma and cervical squamous cell carcinoma respectively using the ADCslow, and ADCfast and Ffast values show no significant positive results in the measurements.

James J Brittin¹, Elizabeth A Sadowski¹, Kristin A Bradley², Emily F Dunn², and Jessica B Robbins^1
1Radiology, University of Wisconsin, Madison, Wisconsin, United States, ²Radiation Oncology, University of Wisconsin, Madison, Wisconsin, United States

BOLD MRI sequences can non-invasively measure oxygen bioavailability in different tissues throughout the body, including the uterine cervix. In our retrospective study involving 11 patients with cervical cancer, we found that treatment with chemoradiation, including high dose intracavitary brachytherapy resulted in decreased cervical tumor oxygenation (P=0.001), possibly due to reduced angiogenesis, reduced tumor volume, and/or increased fibrotic tissue formation. As tumor hypoxia has been shown to be a powerful prognostic indicator for poor outcomes in cervical cancer as well as multiple other malignancies, BOLD MRI may be useful in differentiating between tumors which will and will not be radiosensitive.

Michael Fernandez¹, Sachin Jambawalikar², and Kristin Myers^1
1Mechanical Engineering, Columbia University, New York, NY, United States, ²Radiology, Columbia University Medical Center, New York, NY, United States

The mechanical properties of cervical tissue and cervical geometry are crucial factors in the ability of the cervix to withstand mechanical loading from the fetus during the course of pregnancy. Transport of interstitial fluid inside hydrated tissue such as cervical stroma plays an important role in its mechanical response. Permeability is a mechanical property that characterizes bulk fluid transport within a hydrated tissue or material undergoing mechanical loading. The purpose of this study was to explore the coupled relationship between the diffusive properties of a hydrated material (via ADC) as measured by MRI and its corresponding hydraulic permeability measured in-vitro. These results for polyacrylamide hydrogels are a foundation for the characterization of similar relationships in human cervical tissue which can potentially be used as quantitative clinical biomarkers for cervical mechanical properties and preterm birth risk.

Martine Dujardin¹, Peter Gibbs¹, and Lindsay W Turnbull^1
1Centre for MR Investigations, University of Hull in association with Hull York Medical School, Hull, United Kingdom

Preoperative MR differentiation of borderline ovarian tumour (BOT) from cystadenoma allowing optimal surgical management is important, however challenging. This study investigates the ability of texture analysis (16 textural descriptors) applied to 3T-based high resolution T2-weighted images to distinguish between both lesion types. f14 (maximal correlation coefficient) showed a significant difference between adenoma and BOT (p=0.02; AUC=0.7).

Jie Zhang¹, Qingwei Liu¹, Shifeng Cai¹, Changzhong Li², Xichao Sun³, and Caixia Fu^4
1Radiology, Shandong Provincial Hospital, Shandong University, Jinan, Shandong, China, ²Obstetrics and Gynecology, Shandong Provincial Hospital, Shandong University, Jinan, Shandong, China, ³Pathology, Shandong Provincial Hospital, Shandong University, Jinan, Shandong, China, ⁴Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, Guangdong, China

This study was to investigate whether the choline-containing compounds (Cho) obtained from three-dimension 1H MRS with 3T system is associated with the aggressiveness of endometrial cancer (ECa). Thirty-eight patients with ECa and 19 patients with benign lesions in endometria or in submucosa (BLs-ESm) were included in this study. The ratio of sum of Cho to sum of water (Cho/water) was the statistical unit. The Cho/water can differentiate ECa from BLs-ESm and differentiate type II from type I ECa, but can¡¯t differentiate different stages ECa, as well as different grades ECa. Cho/water increased with the increase of tumor stage and size.

Michiko Kabayashi¹, Yoshiko Hayashida¹, Hodaka Oki¹, Athushi Ogasawara¹, Keita Watanabe¹, Satoru Ide¹, Shingo Kakeda¹, Takatoshi Aoki¹, and Yukunori Korogi^1
1Radiology, University of Occupational and Environmental Helth School of Medicine, Kitakyushu, Fukuoka, Japan

The purpose of our study was to evaluate the utility of Star Map for diagnose of cystic ovarian tumors. 25 patients with pathologically proven ovarian tumors were included in this study. The regions of interest (ROIs) were manually drawn as big as it could be on Star map in areas corresponding to the non-enhancing area. The areas showed high signal intensity on T1WI of ovarian tumors also evaluated. Our results suggested that StarMap could be a helpful tool for diagnosis of ovarian tumors.

Eito Kozawa¹, Masahiro Takahashi², Yusuke Watanabe², Masanori Yasuda², Keiichi Fujiwara², and Fumiko Kimura^2
1Saitama Medical University,International Medical Center, Hidaka-shi, Saitama, Japan, ²Saitama Medical University, International Medical Center, Saitama, Japan

The apparent diffusion coefficient (ADC) has been reported useful in the qualitative diagnosis of tumors and changes that occur as a result of treatment. ADC value is well accepted as a means to differentiate between malignant and benign tumor. It is difficult differentiate between ovarian polypoid endometriosis (OPE) and ovarian endometrioma with malignant tumor (OEMT) because both the tumors contained solid components. We evaluated ADC values whether we could differentiate between OPE and OEMT.

Peter Gibbs¹, Martine Dujardin¹, and Lindsay Turnbull^1
1MRI Centre, HYMS at University of Hull, Hull, East Yorkshire, United Kingdom

MRI is the preferred technique for characterising complex adnexal masses. However, the presence of solid components in both benign and malignant lesions causes diagnostic difficulties. In this work the utility of co-occurrence matrix based textural analysis in the diagnosis of ovarian malignancy is explored. Significant differences between four groups (ovarian cancer, borderline ovarian tumour, cystadenoma and cystadenofibroma) were found for 8 of 16 calculated texture parameters. Regression tree analysis yielded a robust diagnostic model, based on 3 texture parameters, with an overall accuracy of 70%.

shivaprasad ashok chikop¹, sneha Shiradon¹, Pavan Poojar¹, Arush Honnedevasthana Arun¹, Madhu Sudan Muguru Prabhuswamy¹, Sona Pungavkar², and Sairam Geethanath^1
1Medical Imaging Research Centre, Dayananda Sagar Institutions, bangalore, Karnataka, India, ²Department of Radiology, Dr.Balabhai Nanavathi Hospital, Mumbai, Maharastra, India

Computation of fetal brain and lung volume significantly aid in biomarker determination to monitor fetal development for diagnosis and/or prognosis of fetal pathologies. The algorithm does not depend on priors based on intensity and can be used to perform segmentation on T1/T2 contrast. The result shows significant correlation between automated brain, semi-automated lung segmentation with corresponding manual segmentations as quantified by number of segmentation pixels and qualitatively through segmentation results visualized as 3D volumes. Current and future work includes optimization of brain and lung volume visualization for more datasets and obtaining biomarkers to distinguish normal and abnormal fetal pathology.

Yong Pang¹, Jindai Jiang², and Xiaoliang Zhang^1,3
1Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States, ²Department of Radiology, 2nd Hospital of Guangzhou Medical University, Guangzhou, China, ³UCSF/UC Berkeley Joint Graduate Group in Bioengineering, San Francisco & Berkeley, CA, United States

Fetal MRI provides detailed fetal anatomy and is being increasingly used to evaluate fetal development. However, the image quality is degraded by the fetal motion and maternal respiratory and involuntary movements during long acquisition time. In this study, we applied the interpolated compressed sensing method to accelerate the acquisition and increase contrast to noise ratio (CNR) for multi-slice two-dimensional MR imaging. By combining with parallel imaging, the acquisition time can be further reduced. In-vivo MR of a pregnant woman has been used to investigate the feasibility of this method, showing obviously increased CNR compared with the conventional CS.

Gillian Macnaught¹, Scott Semple^1,2, Calum Gray^1,3, Mary Simpson⁴, Jane Norman⁴, Jane Walker⁵, and Fiona Denison^4
1Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, Scotland, United Kingdom, ²Centre for Cardiovascular Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom, ³Wellcome Trust Clinical Research Facility, University of Edinburgh, Edinburgh, Scotland, United Kingdom, ⁴Tommy's Centre for Maternal and Fetal Health, University of Edinburgh MRC Centre for Reproductive Health, Edinburgh, Scotland, United Kingdom, ⁵Simpson Centre for Reproductive Health, Edinburgh Royal Infirmary, Edinburgh, Scotland, United Kingdom

Placental insufficiency commonly leads to Fetal Growth Restriction (FGR) and stillbirth. The current recommendation is to deliver the baby prematurely which is not without risk. We present proton placenta spectra acquired in-utero of 4 FGR and 4 normal pregnancies, acquired on a 3T Siemens Verio MR system using the PRESS technique. Spectra were analysed using JMRUI. The ratios of glutamine and glutamate (Glx) to choline (cho) in the placentas of 4 FGR pregnancies were lower than in their gestation-matched controls. This may provide an in vivo marker of placental function in these difficult to manage cases.

Brijesh Kumar Yadav^1,2, Uday Bhaskar Krishnamurthy^1,2, Yimin Shen¹, Jaladhar Neelavalli^1,2, Gabor Szalai³, Bing Wang³, Tinnakorn Chaiworapongsa^3,4, Edgar Hernandez-Andrade^3,4, Nandor Gabor Than^3,4, Ewart Mark Haacke^1,2, and Roberto Romero^3
1Department of Radiology, Wayne State University, Detroit, Michigan, United States, ²Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States, ³Perinatology Research Branch, NICHD, NIH, DHHS., Wayne State University, Detroit, Michigan, United States, ⁴Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, United States

In this study, the longitudinal variations in the size of high perfusion and low perfusion zones of the normal murine placenta along different gestational ages are quantified using dynamic contrast enhancement magnetic resonance imaging(DCE-MRI) and an automatic segmentation method based on Tissue Similarity Mapping (TSM.

Sonia Isabel Goncalves¹, Mario Ribeiro², Filipe Caseiro-Alves³, and Miguel Castelo-Branco^1
1IBILI-Faculty of Medicine, University of Coimbra, Coimbra, Coimbra, Portugal, ²Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal, ³Faculty of Medicine, University of Coimbra, Coimbra, Portugal

Liver fat fraction (FF) quantification is an important tool that can help staging non-alcoholic fatty liver disease. The gold-standard procedure for FF quantification, is percutaneous biopsy, which is expensive and prone to post-surgical complications. Non-invasive alternatives include magnetic resonance spectroscopy and chemical shift imaging (CSI) using multi-echo gradient-echo (ME-GRE) pulse sequences. The latter method is very appealing because data acquisition is typically fast and well tolerated by patients.Models based on the analysis of magnitude and complex data have been used to separate water and fat components from ME-GRE images and several studies have been dedicated to advantages and disadvantages of each.Despite all the advances, the fact remains that clinical applications of FF quantification using CSI largely overlook these aspects. In this paper, we provide a systematic analysis of different signal models to quantify FF at 3T using ME-GRE pulse sequences with twelve echoes, with a view on optimizing the combination of echo times (TEs). We furthermore study the influence of magnetic field heterogeneities in the accuracy of the complex model for FF estimation.

Thomas Neuberger^1,2, Sooyeon Lee³, Gangchea Lee², and Shannon Kelleher^3
1Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, United States, ²Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, United States, ³Department of Nutritional Sciences, Pennsylvania State University, University Park, PA, United States

Female breasts undergo massive changes to transition from a rudimentary structure into a milk secreting organ and back to the pre-pregnant state. We studied the feasibility of imaging the phenotypic changes within mouse mammary glands using high field MRI. The results will assist in developing tools to utilize mouse models in better understanding breast development and disease in women.

Venkatesh Gopalan¹, Jadegoud Yaligar¹, Swee Shean Lee¹, Navin Michael², and S Sendhil Velan^1,2
1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore, ²Singapore Institute for Clinical Sciences, Singapore, Singapore

Hepatic fat plays a major role in metabolic diseases including obesity, diabetes, and non-alcoholic fatty liver disease (NAFLD). In vivo magnetic resonance spectroscopy (MRS) permits non-invasive longitudinal assessment of fat fraction, saturated and unsaturated lipids. Interventions including exercise and calorie restriction play a major role in anti-obesity and also for recovery from NAFLD. In the current study we have estimated the changes in intrahepatic lipid content including, fat fraction, total unsaturated lipids (TUL), fraction of unsaturated lipid (fUL) and unsaturation index (UI) in five groups of high fat diet (HFD) fed obese rat model with exercise and calorie restriction interventions. Our preliminary results suggest significant reduction and modulation of intrahepatic lipids with exercise and calorie restriction.

Suresh Anand Sadananthan^1,2, Navin Michael¹, Eric Yin Hao Khoo³, Melvin K-S Leow^1,4, ChinMeng Khoo³, Yung Seng Lee^1,5, Peter Gluckman¹, EShyong Tai³, and S. Sendhil Velan^1,6
1Singapore Institute for Clinical Sciences, A*STAR, Singapore, Singapore, ²Department of Obstetrics & Gynaecology, National University of Singapore, Singapore, Singapore,³Department of Medicine, National University of Singapore, Singapore, ⁴Department of Endocrinology, Tan Tock Seng Hospital, Singapore, ⁵Department of Pediatrics, National University of Singapore, Singapore, ⁶Clinical Imaging Research Centre, A*STAR, Singapore

In addition to study of fat distribution in abdominal adipose tissues (visceral, deep and superficial subcutaneous), there has been an increasing interest in the investigation of fatty acid composition in these depots because of their association with insulin sensitivity. Studies have shown that the fatty acid makeup of the different fat compartments vary between each other. Weight loss intervention is known to alter this composition in adipose tissues, with studies showing decreased levels of monounsaturated fatty acids after intervention. In this study, we investigated the potential for non-invasively monitoring the changes in the fatty acid composition of adipose tissue triglycerides due to weight loss intervention using MRS.

Jadegoud Yaligar¹, Diego A Miranda², Bhanu Prakash KN¹, David Lawrence Silver², and S Sendhil Velan^1
1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore, Singapore, ²Signature Research Program in Cardiovascular & Metabolic Diseases, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore

Fat deposition in the body can be regulated by silencing the fat storage-inducing transmembrane (FIT) protein in in vivo animal models. In our current study we have evaluated the abdominal fat in both FIT2 adipose-specific knockout (AF2KO) and their littermate (LL) control mouse model using MRI technique. Volumes of SAT and VAT fat fractions were significantly (p < 0.05) higher in LL control compared to AF2KO mice. Both SAT and VAT fat contents of AF2KO mice were significantly (p < 0.05) lower than LL mice, indicating a vital role of FIT2 in lipid accumulation. Silencing the FIT2 protein has reduced the fat accumulation even in high fat diet fed conditions. Modulation (either down regulation or silencing) of these proteins by drugs in obesity and type 2 diabetic conditions might be helpful in preventing the fat accumulation in the body.

Valeria Righi¹, Silvia Alboni², Luisa Schenetti², Carlo Cifani³, Nicoletta Brunello², and Adele Mucci^4
1Department for the Quality of Life Studies, University of Bologna, Rimini, RN, Italy, ²Department of Life Sciences, University of Modena and Reggio Emilia, Modena, MO, Italy,³School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino, MC, Italy, ⁴Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Modena, MO, Italy

Binge Eating (BE) episodes are characterized by uncontrollable, distressing eating of a large amount of highly palatable food (HPF). Considerable evidence suggests that BE may be caused by a unique interaction between dieting and stress. In our model BE for HPF is evoked in rats by the combination of cyclic food restrictions and stress. In order to investigate BE behavior in female rats, for the first time, we analyzed the metabolic profile obtained from biological fluids of rats exposed or not to cycles of food restriction and a stressful challenge through the High Resolution Nuclear Magnetic Resonance Spectroscopy.

Myriam Diaz Martinez^1,2, Aliya Diaz Gifford^2,3, Philip E Williams⁴, Alan D Diaz Cherrington⁴, Malcolm J Avisom⁵, and E Brian Welch^3,6
1Department of Radiology and Radiological Sciences, Vanderbilt University, School of Medicine, Nashville, TN, United States, ²Chemical and Physical Biology Program, Vanderbilt University Medical Center, Nashville, TN, United States, ³Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States,⁴Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States, ⁵Department of Pharmacology, Vanderbilt University, School of Medicine, Nashville, TN, United States, ⁶Department of Radiology and Radiological Sciences, Vanderbilt University, School of Medicine, Nasville, TN, United States

The purpose of this study was to detect organ-specific changes in fat-water signal over the course of high fat/high fructose diet consumption. The effect of the diet was evaluated exposing a canine animal model to the diet and measurements were acquired using the quantitative method of fat-water MRI (FWMRI), with interleaved multiecho pulse sequence. This technique is a promising new imaging modality for the research areas of obesity and metabolic diseases. Results indicate that liver and subcutaneous tissues fat fraction increased over the course of the study, consistent with the development of obesity comorbidities such as type 2 Diabetes Mellitus.

Loek P. Smits¹, Bram Coolen², Wouter Nijhof¹, Jurgen H. Runge², Erik S. Stroes¹, and Aart J. Nederveen^2
1Department of Vascular Medicine, AMC, Amsterdam, Netherlands, ²Department of Radiology, AMC, Amsterdam, Netherlands

Differentiation between simple steatosis and steatohepatitis (NASH) is of clinical and prognostic importance, but no non-invasive diagnostic tests currently available are capable of this. Previous studies showed the promise of iron-oxide particle enhanced MRI as a diagnostic tool to identify patients with NASH. In the present study we present a protocol for ultrasmall particles of iron-oxide (USPIO) enhanced MRI, and demonstrate that patients with NASH have a decreased hepatic uptake of USPIOs. Future studies are needed to show whether USPIO-MRI indeed is capable of differentiation NASH from simple steatosis.

Peter Bannas^1,2, Utaroh Motosugi¹, Diego Hernando¹, Mahdi S Rahimi³, James H Holmes⁴, and Scott B Reeder^1,5
1Department of Radiology, University of Wisconsin, Madison, Madison, WI, United States, ²Department of Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, ³Department of Biomedical Engineering, University of Wisconsin, Madison, Madison, WI, United States, ⁴Global MR Applications and Workflow, GE Healthcare, Madison, WI, United States, ⁵Department of Medical Physics, University of Wisconsin, Madison, Madison, WI, United States

Gadoxetic acid enhanced hepatobiliary phase MRI is useful for detection of hypointense liver metastases. However, vessels and benign cavernous hemangiomas also appear hypointense on gadoxetic acid enhanced MRI and may be difficult to distinguish from one another. We hypothesized that use of an intravascular contrast agent, gadofosveset trisodium, in addition to gadoxetic acid, may address this issue. The purpose of this work was to demonstrate the feasibility of combined use of these two contrast agents and to optimize MR parameters. We concluded that combination of the two contrast agents is feasible and worth testing in a clinical setting.

Rama Jayasundar¹, Somenath Ghatak¹, Ankur Poddar², Ariachery C Ammini³, and Ashok K Mukhopadhyaya^4
1Department of NMR, All India Institute of Medical Sciences, New Delhi, Delhi, India, ²Department of Biotechnology, All India Institute of Medical Sciences, New Delhi, Delhi, India, ³Department of Endocrinology, All India Institute of Medical Sciences, New Delhi, Delhi, India, ⁴Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi, Delhi, India

With increasing prevalence of metabolic disorders like diabetes, the importance of predictive markers is gaining attention. In this study, MRI based visceral and subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) as an index of metabolic health have been evaluated in Asian Indian population (n = 47), known to have high predisposition to type 2 diabetes. The results were also correlated with biochemical metabolic risk indices and other body composition analysis techniques like DEXA and BIA. SAT at L3 level with maximum correlations and also IMAT at midthigh could be predictive markers in identifying risk population for metabolic disorders.

Kathrin Ogris^1,2, Eva Hassler³, Andreas Petrovic¹, Bernhard Neumayer¹, Thomas Widek¹, and Eva Scheurer^1,2
1Ludwig Boltzmann Institute Clinical-Forensic Imaging, Graz, Styria, Austria, ²Department of Legal Medicine, Medical University of Graz, Styria, Austria, ³Department of Radiology, Medical University of Graz, Styria, Austria

While the detection of hemorrhage in clinical medicine is focused on organs and body cavities forensic imaging requires reliable analysis of hematomas in subcutaneous fatty tissue for the reconstruction of events. In 20 healthy volunteers autologous blood was injected into the subcutaneous tissue of the thigh and repetitive MRI scans of the artificial hematoma were performed. When analyzing the final data, by calculating the Michelson contrast and a morphological evaluation of the hematomas and the fatty tissue, we came across three major influence factors (hematoma shape, fatty tissue structure and hematoma regeneration) for the assessment of the age of bruises.

Maggie M Fung¹, Lloyd Estkowski², Dan Xu³, Suchandrima Banerjee², Pauline Worters², Gaohong Wu⁴, John Skinner⁴, and Ersin Bayram^5
1Global MR Applications and Workflow, GE Healthcare, Jersey City, NJ, United States, ²Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States,³Global MR Applications and Workflow, GE Healthcare, Waukesha, WI, United States, ⁴MR Engineering, GE Healthcare, Waukesha, WI, United States, ⁵Global MR Applications and Workflow, GE Healthcare, Houston, TX, United States

Diffusion weighted whole body imaging is conventionally acquired axially to reduce image distortion due to B0 inhomogeneity in the SI direction. However, axial DWI acquisition requires longer scan time, as compared to coronal acquisition, and direct coronal DWI requires high acceleration factor to reduce distortion. We propose an alternative method for coronal diffusion imaging using 2D spatially selective excitation (FOCUS) that can reduce distortion at lower acceleration factors. We have shown that FOCUS imaging suffers much less distortion compared to conventional rectangular FOV imaging at the same acceleration factor and can be clinically viable for whole body diffusion imaging.

Yeji Han¹, Chang Heun Oh¹, and HyunWook Park^1
1Department of Electrical Engineering, KAIST, Daejeon, Daejeon, Korea

Although whole-body diffusion-weighted imaging (wbDWI) is generally performed using the multistation approach, the continuously moving table (CMT) approach can be used as an alternative to generate images with more homogeneous temporal and spatial continuities. While STIR is an appropriate choice for fat and background signal suppression in 1.5T MRI systems, a more efficient fat-suppression technique is required for the CMT-wbDWI in 3T MRI. In this abstract, an adaptive gradient reversal technique is proposed for the CMT-wbDWI method, where the opposite polarities of slice selection gradients are used for 90° and 180° RF pulses with an RF pulse adaptation.

Shuo Li¹, Huadan Xue², Jian Li³, Haibo Zhang⁴, Zhaoyong Sun², and Zhengyu Jin^2
1department of radiology, Peking Union Medical College Hospital, Beijing, Beijing, China, ²department of radiology, Peking Union Medical College Hospital, Beijing, China,³department of hematology, Peking Union Medical College Hospital, Beijing, China, ⁴Peking Union Medical College Hospital, Beijing, China

Purpose: To analyses the diagnostic potential of DWIBS in the detection and discrimination of focal bone marrow lesions from multiple myeloma (MM). Methods: A prospective analysis including 25 MM patients. 12 newly diagnosed MM patients were divided in active group. 13 MM patients after therapy were divided in stationary group. The mean ADC value was evaluated in all foci lesions > 1 cm. Five regions of bone marrow were calculated. Results: The mean ADC value of active lesions (n=114) was (880.04¡À212.31)¦Ìm2/S, which is significantly lower than that of inactive lesions (n= 80) (1784.29¡À419.17)¦Ìm2/S. The mean ADC value of diffusely infiltrated marrow is (632.91¡À43.52)¦Ìm2/S, higher than those of stationary period bone marrow(286.18¡À25.17) ¦Ìm2/S and only focal myeloma bone marrow(420.25¡À31.11) ¦Ìm2/S. Coclusion: The ADC value allows differentiation between active and stationary myeloma lesions, normal bone marrow and tumors of myeloma.

Sarah A Mason¹, Matthew D Blackledge¹, David J Collins¹, Thorsten Feiweier², Yiliang Thian¹, Dow-Mu Koh¹, and Martin O Leach^1
1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, United Kingdom, ²Healthcare Sector, Siemens AG, Erlangen, Germany

We investigated how the technical differences between ss-EPI(R=2), FLASH(R=2) and FLASH(R=3) ACS acquisition methods visually manifest themselves in the context of WBDWI imaging. We analyzed: geometric distortion, SNR, overall image quality, and inter-station registration. FLASH(R=3) had the highest geometric fidelity, fewer image artifacts, and good station-station alignment. These advantages are offset by a lower SNR of ~17%: this may be partially responsible for the tendency of FLASH(R=2) ACS data to be rated higher than FLASH(R = 3) ACS data in terms of overall MIP quality. There was no situation in this study in which ss-EPI outperformed FLASH.

Moti Freiman¹, Onur Afacan¹, Robert V Mulkern¹, and Simon K Warfield^1
1Radiology, Boston Children's Hospital/Harvard Medical School, Boston, MA, United States

Diffusion-weighted MRI images acquired with multiple b-values have the potential to improve diagnostic accuracy by increasing the conspicuity of lesions and inflammatory activity with background suppression. Unfortunately, the inherently low signal-to-noise ratio (SNR) of DW-MRI reduces enthusiasm for using these images for diagnostic purposes. Moreover, lengthy acquisition times limit our ability to improve the quality of multi b-value DW-MRI images by multiple excitations acquisition and signal averaging at each b-value. To offset these limitations, we propose the Simultaneous Model Estimation and Image Reconstruction (SMEIR) for DW-MRI, which substantially improves the quality of multi b-value DW-MRI images without increasing acquisition times.

Oliver J. Gurney-Champion¹, Martijn Froeling², Remy Klaassen¹, Jaap Stoker¹, Geertjan van Tienhoven¹, Hanneke W.M. van Laarhoven¹, Arjan Bel¹, and Aart J. Nederveen^1
1Academic Medical Center, Amsterdam, Netherlands, ²University Medical Center Utrecht, Netherlands

The perfusion fraction, f, obtained from intravoxel incoherent imaging can potentially be used as biomarker to distinguish between pancreatic carcinomas and healthy tissue. Using an optimized imaging sequence, together with an in-house post-processing toolkit in eight healthy volunteers, we show a good reproducibility for f (RI=17%) and diffusion coefficient, D, (RI=13%). Averaging over all volunteers we found D=1.40±0.07x10-3 mm3/s, f=9.4±1.8 % and pseudo-diffusion coefficient D*=0.0871 mm3/s . We showed how the RI decreases for decreasing number of averages. Finally, for one patient, we could observe a difference in f between healthy and tumorous pancreas tissue.

Chao Ma¹, Yanjun Li¹, Luguang Chen¹, Yang Wang², Yong Zhang³, He Wang³, Shiyue Chen¹, and Jianping Lu^1
1Radiology, Changhai Hospital of Shanghai, Shanghai, Shanghai, China, ²Pathology, Changhai Hospital of Shanghai, Shanghai, Shanghai, China, ³MR group, GE healthcare, Shanghai, Shanghai, China

The purpose of the study was to identify prospectively potential associations between the DWI-derived IVIM parameters such as f (perfusion fraction), ADCfast (pseudo-diffusion coefficient), ADCslow (the tissue diffusivity) and these parameters with the commonly used DWI-derived ADCs of pancreatic adenocarcinoma and the tumor grade as well as other pathological features.

Motoyuki Katayama¹, Takayuki Masui¹, Kimihiko Sato¹, Kei Tsukamoto¹, Kenichi Mizuki¹, Mitsuharu Miyoshi², and Nami Matsunaga^2
1Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan, ²GE Healthcare Japan, Hino, Tokyo, Japan

We compared the performance of FOCUS DWI for evaluation of intra-pelvic tumor with that of conventional DWI. 14 patients with pelvic tumor who underwent 3.0T MRI were included in this study. Correlation coefficient of ADC with FOCUS and conventional DWI was 0.79. On qualitative analysis, conspicuity and structural visualization of tumor in FOCUS DWI was superior to that of Conventional DWI. FOCUS DWI is useful for evaluation of intra-pelvic tumor.

Eddy Solomon¹, Reut Avni², Peter Bendel³, Lucio Frydman¹, and Michal Neeman^2
1Chemical Physics, Weizmann Institute of Science, Rehovot, Israel, ²Biological Regulation, Weizmann Institute of Science, Rehovot, Israel, ³Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel

Novel diffusion-based MRI methodologies relying on SPatio-temporal ENcoding (SPEN) were developed, and used to uncover in-vivo aspects about the diffusion of fluids in mouse placenta. Macromolecular contrast agents were used to distinguish the ADC’s of maternal blood capillaries, fetal blood capillaries and trophblast giant cells. Significantly, different diffusion and perfusion properties were thus noticed, spanning nearly two orders of magnitude. This yields a new multiparametric view of the placenta whereby mainly free diffusion occurs in the maternal blood, a strongly forced perfusion is observed in the fetal microcapillaries, and moderate fluid exchanges characterizes the trophoblasts lining the maternal blood pool.

Thierry Metens¹, Kellen Fanstone-Ferraresi¹, Alessandra Farchione¹, Maria Antonietta Bali¹, Julie Absil¹, Christophe Moreno¹, and Celso Matos^1
1IRM Hôpital Erasme, Université Libre de Bruxelles, Bruxelles, Belgium

In diffusion-weighted images the normal liver signal intensity is associated with age and gender in healthy subjects and is correlated with T2* and serum ferritin. ADC values are influenced by T2*values

Christian Eberhardt¹, Moritz Wurnig¹, Andrea Vuck², Mickael Lesurtel², and Andreas Boss^1
1Department of Diagnostic and Interventional Radiology, University Hospital Zürich, Zürich, Switzerland, ²Department of Visceral and Transplant Surgery Research, University Hospital Zürich, Zürich, Switzerland

Intravoxel incoherent motion MRI (IVIM-MRI) has lately been increasingly used in clinical studies on a variety of diseases. As animal models are widely used in translational research, the objective of this study was to establish tissue diffusion and perfusion parameters of murine abdominal organs serving as reference for the discrimination of tissue pathologies in animal disease models. Here, the pseudodiffusivity (Dp), tissue diffusivity (Dt) and the perfusion fraction (fp) of the liver, renal cortex, renal medulla, spleen and small bowel were characterized by IVIM- MRI on a large cohort of C57Bl/10 mice (n=50).

Yvonne Simrén¹, Eira Stokland¹, Sverker Hansson², P-A Svensson¹, and Kerstin Lagerstrand^3
1Department of Pediatric Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden, ²Department of Pediatrics, Sahlgrenska University Hospital, Gothenburg, Sweden,³MR centre, Sahlgrenska University Hospital, Gothenburg, Sweden

Problem Free breathing renal diffusion weighted MR imaging (DWI) is sensitiv to motion artefacts. Methods Thirteen infants were scanned during free breathing without sedation. Signal to noise ratio (SNR) was compared between conventional DWI, tetrahedral DWI and diffusion tensor imaging (DTI). Results The decrease in SNR was significantly lower for DTI (0.36±0.11) than for cDWI (0.52± 0.08; p<0.05) and tDWI (0.54±0.1; p<0.05) indicating higher image quality. There was no significant difference in SNR for tDWI compared to cDWI (p=0.08). Conclusion The image quality in DTI appears to be superior to conventional and tetrahedral DWI in free breathing renal imaging.

Neil P Jerome¹, Matthew R Orton¹, James d'Arcy¹, Dow-Mu Koh², David J Collins¹, and Martin O Leach^1
1CR-UK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research, Sutton, Surrey, United Kingdom, ²Department of Radiology, Royal Marsden Hospital, Sutton, Surrey, United Kingdom

Blurring, commonly observed in abdominal DWI, arises from respiratory motion between successive acquisitions of signal averages and diffusion gradient directions. Storing coronal DWI images separately allows post-processing alignment by voxel-wise shifting, correcting for a large amount of (predominantly in-plane) respiratory motion. In a volunteer cohort (n=10), residual sum-of-squares as a proxy for uncertainty of IVIM model parameters decreased for renal ROIs following shifting, and further decreased with the exclusion of apparent outlier images. Voxel-wise shifting provides improved confidence in local DWI parameters along with sharper tissue boundaries within images and parameter maps, using a simple and computationally inexpensive method.

Jia Liu¹, Kai Zhao¹, and Xiaoying Wang^1
1Peking University First Hospital, Beijing, Beijing, China

Usage of iodinated contrast medium during radiological procedure may cause contrast induced nephropathy (CIN). Unfortunately the pathogenesis of CIN is currently unclear, and maybe characteristics of contrast medium affect the development of CIN. Our study demonstrated that it is feasible to monitor the time course effects on renal function after different iodinated contrast medium administration in rabbit models using diffusion-weighted MR imaging. Iopamidol-370 causes more deterioration on intrarenal water transport function than iodixanol-320. This may be helpful to understand the pathogenesis associated with CIN. We introduce a clinical clue to choose better contrast medium to prevent the incidence of CIN.

Yu-Chen TSAI¹ and Teng-Yi Huang^1
1Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan

This study aims to apply intravoxel incoherent motion (IVIM) method to free-breathing abdomial imaging. Previous studies acquired diffusion-weighted imaging with prospective respiratory gating multiple averages, and 10 b values. We proposed to acquire images with 91 b values and no averages, and without respiratory-gating. We used a retrospective selection algorithm based on rejecting indexes calculated from fitting residuals. The spatial variations obtained using the proposed method was comparable to that obtained using the protocol presented in the previous study. We concluded that the proposed method is a useful alternative to the respiratory-gated acquisition methods and can be a practical method for abdominal IVIM imaging.

Alexander D Cohen¹, Mark D Hohenwalter², and Kathleen M Schmainda^2
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, ²Radiology, Medical College of Wisconsin, Milwaukee, WI, United States

The intravoxel incoherent motion (IVIM) analysis technique has been used to model diffusion in the liver. Perfusion-related components can be extracted from the DWI signal through the collection of multiple b-values. Once the data is collected, there are a number of different ways to analyze that data. IVIM parameter values were compared with different ROIs and analysis techniques in order to determine which combination provided the best separation between normal and cirrhotic livers. Differences were found for different ROI sizes. Larger ROIs provided better separation between normal and cirrhotic livers, and voxelwise extraction techniques were less variable than ROI techniques.

Alexander D Cohen¹, Moira C Schieke², Mark D Hohenwalter², and Kathleen M Schmainda^2
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, ²Radiology, Medical College of Wisconsin, Milwaukee, WI, United States

The intravoxel incoherent motion (IVIM) analysis technique has been used to model diffusion in the liver. This model allows for the extraction of perfusion-related components from the DWI signal. When b<50 s/mm² are not included in the b-value distribution, the pseudodiffusion parameter has tended to be lower than when b<50 s/mm² are included. This study used simulations to examine the effect of very low b-values on the pseudodiffusion parameter. Pseudodiffusion tended to be underestimated when very low b-values were excluded from the distribution. It is recommended to include at least two very low b-values when performing IVIM studies in the liver.

Diego Hernando¹, Utaroh Motosugi^1,2, Peter Bannas^1,3, Samir D. Sharma¹, and Scott B. Reeder^1,4
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, ²Radiology, University of Yamanashi, Yamanashi, Japan, ³Radiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany, ⁴Medicine, University of Wisconsin-Madison, Madison, WI, United States

Cardiac motion-related effects are severe in liver diffusion MRI, where they introduce signal voids in diffusion-weighted images (particularly in the left liver lobe) and result in errors and high variability in ADC measurements. This variability has precluded the widespread application of quantitative liver diffusion MRI. In this work, we characterize cardiac motion effects on liver diffusion imaging, and assess simple correction techniques to reduce variability in ADC maps by taking maximum intensity over multiple signal acquisitions (ADCMIP), in which we hypothesized we could exclude signals affected by cardiac motion. The ADCMIP was less affected by cardiac-motion than conventional ADC maps.

Jin Yamamura¹, Murat Karul¹, Sarah Keller¹, Tony Manfred Schmidt¹, Axel Heinemann², Gerhard Adam¹, and Roland Fischer^3,4
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, ²Department for Forensic Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, ³Department for Biochemistry, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany,⁴Paediatric Haematology, Children's Hospital Oakland Research Institute, Oakland, CA, United States

So far, there are few DWI investigations of corpses. The most recent study using DWI (including ADC-Mapping) in post mortem brain seemed to be useful and especially promising in forensic medicine. The purpose of this study was to assess both the changes in water diffusion quantified by diffusion-weighted MR imaging in post mortem liver tissue and to examine the development of the apparent diffusion coefficient (ADC) in the liver after death in comparison to ADC values in vivo tissue.

Burkhard Mädler^1,2 and Jürgen Gieseke^2,3
1Neurosurgery, University of Freiburg, Freiburg, Germany, ²Philips Healthcare, Hamburg, Germany, ³Radiology, University of Bonn, Bonn, Germany

Several studies have utilized IVIM for various clinical applications in the abdomen. We tested performance and validity of a novel semi-continuous multi-exponential PFG-diffusion signal analysis for the detection and quantification of vascular perfusion in the liver with a patient friendly free-breathing approach. Classical chi-squared multi-exponential fitting algorithms are susceptible to fail without sufficient SNR. We show that regularized NNLS-techniques together with high number of b-value DWI-acqusition have better performance on the estimates of IVIM parameters and might encourage new attempts of clinical IVIM-based methods in general.

Jiyoung Hwang¹, Kyung Mi Jang², Seong Hyun Kim², and Mi Hee Lee^3
1Department of Radiology, Soonchunhyang University Seoul Hospital, Seoul, Seoul, Korea, ²Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Seoul, Korea, ³Radiology, Samsung Medical Center, Sungkyunkwan University, Seoul, Seoul, Korea

Purpose: To evaluate the added value of diffusion-weighted (DW) MR imaging for differentiating between malignant and benign focal splenic lesions. Methods: This study included 53 patients with 11 malignant and 42 benign splenic lesions and who underwent gadoxetic acid-enhanced and DW MR imaging. Qualitative and quantitative analyses were conducted for splenic lesions. Results: All malignant lesions showed a hypovascular progressive enhancement pattern, while hypervascular enhancement patterns were only demonstrated in benign lesions (20, 47.6%) (P<0.05). The mean ADC of malignant lesions was lower than that of benign lesions (P< .001). The addition of DW images to conventional MR images showed a significant improvement for predicting malignant splenic lesions (P < 0.001) Conclusion: The addition of DW imaging to conventional MR imaging improves differentiation of malignant from benign splenic lesions.

Suresh Anand Sadananthan^1,2, Navin Michael¹, Melvin K-S Leow^1,3, ChinMeng Khoo⁴, Eric Yin Hao Khoo⁴, Yung Seng Lee^1,5, Peter Gluckman¹, EShyong Tai⁴, and S. Sendhil Velan^1,6
1Singapore Institute for Clinical Sciences, A*STAR, Singapore, Singapore, ²Department of Obstetrics & Gynaecology, National University of Singapore, Singapore, Singapore,³Department of Endocrinology, Tan Tock Seng Hospital, Singapore, ⁴Department of Medicine, National University of Singapore, Singapore, ⁵Department of Pediatrics, National University of Singapore, Singapore, ⁶Clinical Imaging Research Centre, A*STAR, Singapore

The study of fat distribution is important to understand the pathophysiology of obesity-related disorders, diabetes mellitus and cardiovascular diseases. Several studies have suggested that the fat distribution is different across different ethnic groups. In addition to the analysis of fat distribution, the investigation of the fatty acid composition is also important because of their varying metabolic properties and association with insulin sensitivity. Differences in the fatty acid composition induced by diet or ethnicity could potentially make some groups more susceptible to metabolic disorders. In this study, we investigated the fatty acid composition in the abdominal deep subcutaneous adipose tissue of three ethnicities (Chinese, Malays and Indians) non-invasively using MRS approaches.

Peter E Thelwall¹, Fiona E Smith¹, Mark Leavitt², David Canty², Wei Hu², Kieren G Hollingsworth¹, Christian Thoma³, Michael Trenell³, Roy Taylor¹, Joseph V Rutkowski², Andrew M Blamire¹, and Anthony G Quinn^2
1Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, ²Synageva Biopharm Corp, Lexington, MA, United States, ³Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom

Cholesterol Ester Storage Disease (CESD) is caused by accumulation of cholesterol esters due to mutation in the gene encoding the enzyme Lysosomal Acid Lipase. We have demonstrated that hepatic ¹H spectroscopy can be used to detect and quantify elevated hepatic cholesterol ester content. We performed preclinical studies on a rat model of CESD to demonstrate the ability of ¹H MRS to quantify the effects of a novel enzyme replacement therapy. Furthermore, we translated our methods to human studies and demonstrated that elevated hepatic cholesterol ester content can be observed in patients with CESD.

Michael D Nelson¹, Laura Smith¹, Edward W Szczepaniak¹, Ruchi Mathur¹, Richard N Bergman¹, and Lidia S Szczepaniak^1
1Cedars-Sinai Medical Center, Los Angeles, California, United States

The risk for heart failure in obesity and diabetes is greater than can be accounted for by traditional factors of hypertension and coronary artery disease. Altered substrate metabolism may contribute to dysfunction of diabetic heart. In obesity and diabetes contribution of glucose oxidation to cardiac energetics is sub-normal with enhanced reliance on fatty acid metabolism. Most work in cardiac metabolism has been performed in rodent models. We present results from a study in which we altered cardiac metabolism by 48 hours fasting in humans. Cardiac metabolism was assessed by myocardial triglyceride content and diastolic function assessed by myocardial tissue tagging.

Åsa Carlsson^1,2, Maja Sohlin^1,2, Sofi Holmquist², Eva Forsell-Aronsson², and Maria Ljungberg^1
1Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, VGR, Sweden, ²Radiation Physics, Gothenburg University, Gothenburg, VGR, Sweden

During last years a diet with low carbohydrate and high fat content (LCHF) has become very popular in Sweden. There is, however, very little knowledge about the internal and long term effects of this kind of diet. In this study, cardiac MR spectroscopy is used to measure the myocardial lipid content in dieting and non-dieting volunteers. For both groups the myocardial lipid content was dependent on body mass index (BMI) and waist to hip ratio (WHR) alone. The group on diet showed excessive myocardial lipid content compared to the non-dieting group.

Lucas Lindeboom^1,2, Christine Nabuurs^1,3, Matthijs Hesselink³, Joachim Wildberger¹, Vera Schrauwen-Hinderling^1,2, and Patrick Schrauwen^2
1Dept. of Radiology, MUMC+, Maastricht, Netherlands, ²Dept. of Human Biology, MUMC+, Maastricht, Netherlands, ³Dept. of Human Movement Sciences, MUMC+, Maastricht, Netherlands

We demonstrate that the postprandial storage of dietary fat, after a single high fat breakfast, can be measured with 1H-MRS. Nine lean healthy subjects were included in this study and intrahepactic and intramyocellular lipids were measured 3h and 5h after a single breakfast. The addition of protein to the diet, did not change the deposition of lipids.

Nigel Paul Davies^1,2, Robert Flintham³, Reina Lim⁴, and Jeremy W Tomlinson^4
1Imaging & Medical Physics, University Hospitals Birmingham NHS Foundation Trust, Birmingham, West Midlands, United Kingdom, ²School of Cancer Sciences, University of Birmingham, Birmingham, West Midlands, United Kingdom, ³Imaging & Medical Physics, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom,⁴University of Birmingham, Birmingham, United Kingdom

Hepatitis C virus (HCV) is a RNA virus with diverse genotypes and a broad spectrum of clinical outcome. Non-invasive methods for assessing disease severity and predicting treatment response are sought. In-vivo ¹H MRS at multiple TE with correction for T2 decay has been used to investigate liver fat and total choline (tCho) levels in treatment-naïve HCV patients with early-stage liver disease compared with healthy controls. No significant differences in lipid levels were found. tCho was significantly higher in the HCV group compared with the controls. Potential changes in liver choline levels in HCV after a novel drug treatment will be investigated.

Jurgen H. Runge¹, Wybe J.M. van der Kemp², Dennis W.J. Klomp², Aart J. Nederveen¹, and Jaap Stoker^1
1Radiology, Academic Medical Center, Amsterdam, Netherlands, ²Radiology, University Medical Center Utrecht, Utrecht, Netherlands

Patients with diffuse hepatic disease (e.g. viral hepatitis and NASH) may present with liver fibrosis or inflammation. Preliminary studies indicate that ³¹P-MRS may play a role in the non-invasive determination of liver inflammation by mapping NADPH concentration. We compared 2D MRSI at 3T with a SNR optimized 7T set-up and implemented the adiabatic multi-echo spectroscopic imaging sequence (AMESING) of the liver at 7T for further SNR gain. SNR increased by 1.3 to 3.1 between 3T and 7T while AMESING further boosted SNR by 1.2 to 1.6, showing its potential for the quantitative mapping of metabolite concentrations throughout the liver.

Elise Bannier¹, Amandine Coum^2,3, Anne Boulic⁴, Giulio Gambarota^2,3, and Yves Gandon^4
1Unité VISAGES U746 INSERM-INRIA, IRISA UMR CNRS 6074, University of Rennes, Rennes, France, ²INSERM, UMR 1099, Rennes, France, ³Université de Rennes 1, LTSI, Rennes, France, ⁴Radiology Department, University Hospital of Rennes, Rennes, France

The purpose of the present study was to assess the ability of MR spectroscopy to quantify hepatic liver fat overload in the presence of low to moderate iron overload and compare the results with multi gradient echo MR imaging and percutaneous liver biopsy. Multi-spectral fat composition and quantification of saturated and unsaturated fatty acid ratios were also investigated. Fat fraction measurements obtained using MR spectroscopy, imaging and biopsy were well correlated. While MRI allows imaging of the whole liver, MR spectroscopy enables quantification of saturated and unsaturated fatty acid ratios

Gavin Hamilton¹, Michael S Middleton¹, Tanya Wolfson², Anthony C Gamst², Jonathan C Hooker¹, William M Haufe¹, Brandon D Ang³, Rohit Loomba³, and Claude B Sirlin^1
1Department of Radiology, UC San Diego, San Diego, California, United States, ²Computational and Applied Statistics Laboratory, SDSC, UC San Diego, San Diego, California, United States, ³Department of Medicine, UC San Diego, San Diego, California, United States

We developed a rapid multi-TR, multi-TE ¹H MRS sequence for in vivo hepatic fat quantification and characterization that acquires 32 single-average spectra in a single breath-hold. Spectra were acquired without contrast at 3 Tesla in 55 adult subjects who also were undergoing a clinical liver biopsy. T1 and T2 of liver fat and water, and liver proton density fat fraction (PDFF) were measured and compared with histologic fibrosis stage. There were significant differences in water T2 with fibrosis, with higher values being associated with advanced fibrosis.

Stefan Ruschke¹, Thomas Baum¹, Hendrik Kooijman², Marcus Settles¹, Axel Haase³, Ernst J. Rummeny¹, and Dimitrios C. Karampinos^1
1Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany, ²Philips Healthcare, Hamburg, Germany, ³Zentralinstitut für Medizintechnik, Technische Universität München, Garching, Germany

Eddy current effects can distort peak line shapes in DW-MRS, inducing asymmetric peaks and causing bias in the peak area quantification. Previous approaches require a reference signal to correct for eddy current effects. However, finding a reference signal is not always feasible in the presence of water and fat peaks. In the present work, an approach acquiring spectra with opposite diffusion gradient polarities and using an appropriate signal combination routine is proposed to correct for eddy current effects. Examples from the application of the proposed approach are shown in bone marrow and skeletal muscle, where both water and fat peaks are present.

Petros Martirosian¹, Michael Erb², Susanne Will¹, Fritz Schick¹, Sergios Gatidis³, Holger Schmidt^3,4, Nina F Schwenzer^1,3, and Christina Schraml^1,3
1Section on Experimental Radiology, University of Tübingen, Tübingen, Germany, ²Department of Biomedical Magnetic Resonance, University of Tübingen, Tübingen, Germany,³Department of Diagnostic and Interventional Radiology, University of Tübingen, Tübingen, Germany, ⁴Department of Preclinical Imaging and Radiopharmacy, University of Tübingen, Tübingen, Germany

Diffusion-weighted imaging (DWI) of abdominal organs can require considerable measurement time, especially if respiratory triggering is performed. Here we present an approach to reduce the scan time of abdominal DWI by multiband-accelerated technique utilizing simultaneous radiofrequency excitation and acquisition of multiple slices. Our results reveal that a reduction of measuring time at least by 50 % is achievable without substantial compromising image quality using respiratory triggering. Multiband-accelerated technique seems to be a promising approach to reduce acquisition time in abdominal DWI applications for clinical routine.

Lisa M Harris¹, Nina Tunariu¹, Nandita M deSouza¹, Sharon Giles¹, Veronica Morgan¹, Alison MacDonald¹, Martin O Leach¹, and Geoffrey S Payne^1
1CRUK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey, United Kingdom

Lactate is an important metabolite in the assessment of malignant tissue detectable by magnetic resonance spectroscopy. It is often difficult to clinically detect the lactate methyl resonance, as the peak at 1.3 ppm is frequently obscured by intense lipid resonances. In this study we have successfully evaluated a selective homonuclear multiple quantum coherence transfer CSI (SelMQC-CSI) sequence in a small test group of patients with abdominal lesions. It was possible to detect and measure lactate in three patients (mean ± sd = 16.5 ± 1.7 mM, not corrected for T1 or T2, CRLB < 1.4) with abdominal lesions at 1.5T.

Janet Friedrich¹, Julia Schröder¹, Sarah Kindgen², Stefan Fischer¹, Mark Schuppert¹, Karsten Gogoll², Peter Langguth², and Laura Maria Schreiber^1
1Department of Radiology, Johannes Gutenberg University Medical Center, Mainz, Germany, ²Institute of Pharmaceutical Technology and Biopharmacy, Johannes Gutenberg University, Mainz, Germany

The aim of the present work was the evaluation of different fluor containing substances in reference to their MR properties (relaxation times, signal intensity, spectra) and their potential usage in further investigations of drug dissolution processes. Perfluoro-15-crown-5-ether (PFCE), toothpaste jelly and two fluorinated alkanes were investigated. From MR side PFCE and SFA2 turned out to be the most attractive substances among the investigated compounds. However, the advantageous chemical properties assigned SFA2 as the most promising compound. Thus, a first tablet loaded with SFA2 was prepared and imaged.

Toshihiro Furuta^1,2, Masayuki Yamaguchi¹, Ryutaro Nakagami^1,3, Masaaki Akahane⁴, Manabu Minami⁵, Kuni Ohtomo⁴, and Hirofumi Fujii^1
1Division of Functional Imaging, Research Center for Innovative Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan, ²Department of Radiology, Research Hospital, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, Japan, ³Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan, ⁴Department of Radiology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan, ⁵Department of Radiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan

To investigate whether hepatic MR signal recovery in SPIO-enhanced MR imaging could be a marker for early diagnosis of irradiated areas, we investigated hepatic MR signal changes after X-irradiation to previously SPIO-accumulated rat livers and examined the relationship between hepatic MR signal and iron deposits. Sequential T₂*-weighted MR images demonstrated signal recovery delay only in irradiated liver areas within 4 days. It seems that the signal recovery delay was due to SPIO-derived iron deposition because hepatic signal intensity negatively correlated with hepatic iron deposits. Hepatic signal recovery could be a novel diagnostic marker for the delineation of irradiated areas.

Laia Chavarria^1,2, Jordi Romero-Giménez^1,2, Eva Monteagudo³, Juan Córdoba^1,2, and Silvia Lope-Piedrafita^3,4
1Liver Unit, Hospital Vall Hebron, Barcelona, Barcelona, Spain, ²Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Barcelona, Spain, ³Servei de RMN, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain, ⁴Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona, Spain

Intracranial hypertension is a severe complication of acute liver failure (ALF) secondary to brain edema. The pathogenesis of cerebral edema in ALF is not clear but it is known that energy metabolism alterations are involved where a genesis of lactate seems to have an important role. We have studied the dynamic synthesis of brain metabolites using hyperpolarized 1-13C pyruvate in a rat model of ALF. We have found that ALF rats have a significant increase in the lactate/pyruvate ratio as compared to Control rats. Also, the production rate of lactate and alanine was higher in ALF rats.

Marco Borri¹, Maria A. Schmidt², Kristiana D. Gordon^2,3, Julie Hughes², Erica D. Scurr², Dow-Mu Koh², Peter S. Mortimer^2,3, and Martin O. Leach^2
1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden, Sutton, Surrey, United Kingdom, ²CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden, Surrey, United Kingdom, ³Department of Medicine, St George's University of London, London, United Kingdom

Breast cancer-related lymphoedema remains one of the most common and distressing morbidities in breast cancer survivors treated with surgery. In this work we have extended the use of Contrast-Enhanced MR Lymphangiography to upper limbs and produced high resolution MR images of lymphatic vessels at 1.5T. We propose a new quantitative protocol, which employs an intradermal injection with lower concentration of contrast agent and prevents T2*-related signal loss, allowing correct modelling of contrast agent uptake and minimizing venous enhancement. This protocol appears suitable for quantitative studies, and enables both structural and functional evaluation of the lymphatic system within the same examination.

James D Quirk¹, Yulin V Chang¹, and Dmitriy A Yablonskiy^1
1Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, United States

Lung morphometry with hyperpolarized helium-3 MRI is a highly sensitive technique for the non-invasive measurement of alveolar microstructural parameters. Herein, we establish the reproducibility and diffusion direction dependence of this technique in five healthy subjects. The values of all lung morphometry parameters (including acinar duct radius, alveolar depth, and mean chord length) were highly reproducible over the short and long-term and did not depend upon the direction of the applied diffusion gradient. Together, this provides confidence for the use of helium-3 lung morphometry for longitudinal studies and clinical trials.

Hooman Hamedani¹, Stephen J. Kadlecek¹, Masaru Ishii², Yi Xin¹, Hoora Shaghaghi¹, Biao Han¹, Sarmad Siddiqui¹, Sarah Zarrin³, Milton Rossman¹, and Rahim R. Rizi^1
1University of Pennsylvania, Philadelphia, PA, United States, ²Johns Hopkins University, Merryland, United States, ³University of Pennsylvania, PA, United States

While hyperpolarized (HP) gas MRI has been used to estimate alveolar oxygen tension (p_AO₂) [1], it has not been systematically compared to Gold standard to assess its potential for monitoring disease progression and response to new therapies. In this work, we compare imaged p_AO₂ to data produced via pulmonary function test, six-minute walk test, and St.-George Questionnaire.

Greetje Vande Velde¹, Tom Dresselaers², Ellen De Langhe^2,3, Jennifer Poelmans², Rik Lories^2,3, and Uwe Himmelreich^2
1Imaging & Pathology, KU Leuven, Leuven, Flanders, Belgium, ²KU Leuven, Flanders, Belgium, ³UZ Leuven, Flanders, Belgium

Longitudinal MRI may enable sensitive assessment of lung fibrosis onset and progression in free-breathing mice, without radiotoxicity concerns or invasive endpoint measurements. We compared the potential of UTE and self-gated MRI with a conventional respiratory triggered pulse sequence to monitor lung fibrosis onset and progression in the bleomycin-induced pulmonary fibrosis mouse model. All three MRI protocols could sensitively visualize and quantify lung disease onset and progression in individual mice. In vivo MRI results correlated strongly with µCT and histological readouts for lung fibrosis. MRI is therefore a safe and non-invasive alternative to invasive methods for screening novel anti-fibrotic therapies.

Suryanarayanan S Kaushik^1,2, Scott H Robertson^2,3, Matthew S Freeman^2,3, Craig Rackley⁴, Zackary I Cleveland^2,5, Mu He², Rohan S Virgincar^1,2, Kevin T Kelly⁶, William M Foster⁴, Justus E Roos⁵, H Page McAdams⁵, and Bastiaan Driehuys^2,5
1Biomedical Engineering, Duke University, Durham, NC, United States, ²Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States,³Graduate Program in Medical Physics, Duke University, Durham, NC, United States, ⁴Pulmonary, Allergy and Critical Care Medicine, Duke University Medical Center, Durham, NC, United States, ⁵Radiology, Duke University Medical Center, Durham, NC, United States, ⁶Radiation Oncology, Duke University Medical Center, Durham, NC, United States

MRI of dissolved-phase hyperpolarized ¹²⁹Xe has emerged as a non-invasive probe of gas-exchange in the lung. Through dissolved-phase spectroscopy resolving the 197 ppm barrier tissue and 217 ppm red blood cells (RBC) resonances, we have shown that subjects with pulmonary fibrosis (PF) display a dramatically reduced RBC signal, indicative of diffusion limitation. Here, we show the initial results in creating separate images of ¹²⁹Xe in the barrier tissue and the RBCs, using a 3D 1-pt Dixon approach. Preliminary application of the technique to PF now reveals diffusion impairment regionally.

Suryanarayanan S Kaushik^1,2, Matthew S Freeman^2,3, Craig Rackley⁴, Jane Stiles⁴, William M Foster⁴, Justus E Roos⁵, H Page McAdams⁵, and Bastiaan Driehuys^2,5
1Biomedical Engineering, Duke University, Durham, NC, United States, ²Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States,³Graduate Program in Medical Physics, Duke University, Durham, NC, United States, ⁴Pulmonary, Allergy and Critical Care Medicine, Duke University Medical Center, Durham, NC, United States, ⁵Radiology, Duke University Medical Center, Durham, NC, United States

When inhaled, the moderate solubility of hyperpolarized (HP) ¹²⁹Xe gives rise to two distinct resonances, in the barrier tissue and plasma (197 ppm) and in the RBC (217 ppm). This “dissolved-phase” of HP ¹²⁹Xe has emerged as a non-invasive probe of pulmonary gas-transfer. While the current gold-standard to measure gas-transfer is DL_CO, it is highly variable, and requires good subject compliance. In this work, we use HP ¹²⁹Xe spectroscopy as a global biomarker of pulmonary gas-transfer, establish its baseline value in healthy subjects and show that it is dramatically reduced in subjects with pulmonary fibrosis.

Khadija Sheikh^1,2, Weijing Ma^1,2, Fumin Guo^1,3, Sarah Svenningsen^1,2, Terry M Peters^1,2, Harvey O Coxson⁴, David G McCormack⁵, Roya Etemad-Rezai⁶, and Grace Parraga^1,2
1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada, ²Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada, ³Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada, ⁴Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada, ⁵Department of Medicine, The University of Western Ontario, London, Ontario, Canada, ⁶Department of Medical Imaging, The University of Western Ontario, London, Ontario, Canada

Ultra-short echo-time ¹H MRI provides pulmonary ¹H signal intensity (SI) measurements of tissue density. The objective of this study was to evaluate three-week reproducibility of ¹H UTE MRI SI in subjects with bronchiectasis and chronic bronchitis/chronic obstructive pulmonary disease (COPD) and compare with ³He MRI measurements of apparent diffusion coefficients (ADC). This is the first evaluation of ¹H UTE SI reproducibility in bronchiectasis and COPD subjects and there were high Pearson correlation coefficients, relatively low COV and high ICC; reproducibility was high and similar to ³He ADC reproducibility in the same subjects.

Dante P Capaldi^1,2, Fumin Guo^1,3, Sarah Svenningsen^1,2, Weijing Ma^1,2, Khadija Sheikh^1,2, Roya Etemad-Rezai¹, Jonathon Leipsic⁴, Harvey O Coxson⁴, David G McCormack⁵, and Grace Parraga^1,2
1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada, ²Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada, ³Graduate Program in Biomedical Engineering, The University of Western Ontario, London, Ontario, Canada, ⁴Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada, ⁵Department of Medicine, The University of Western Ontario, London, Ontario, Canada

Free-breathing non-contrast enhanced ¹H MRI ventilation imaging using Fourier decomposition has not yet been optimized at 3T or in patients with severe chronic obstructive pulmonary disease (COPD) or bronchiectasis in whom there are both airway and parenchymal abnormalities. Our objective was to compare FDMRI with hyperpolarized 3He MRI to visualize pulmonary ventilation abnormalities in subjects with bronchiectasis and COPD. Thirty subjects were evaluated using hyperpolarized ³He MRI and FDMRI of the dynamic free tidal-breathing MRI acquired over two minutes. There was excellent spatial correlation between ventilation defects visualized using both MR methods.

Jennifer Benjamin¹, Talissa A. Altes¹, Luke Lancaster¹, Eduard E. de Lange¹, Frank Goerner¹, F. William Hersman^2,3, Iulian C. Ruset³, Jaime H. Mata¹, G. Wilson Miller¹, Patrice Rehm¹, Jason Woods⁴, and John P. Mugler, III^1
1Radiology, University of Virginia, Charlottesville, VA, United States, ²Physics, University of New Hamshire, Durham, NH, United States, ³Xemed, Durham, NH, United States, ⁴Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States

Hyperpolarized Xe-129 MR lung ventilation imaging provides high spatial and temporal resolution images as compared with the clinical standard for lung ventilation imaging, scintigraphy. In this study, Tc-99m DTPA aerosol SPECT scintigraphy was compared with Xe-129 MR lung ventilation imaging in 14 subjects with lung disease (7 asthma and 7 COPD). Ventilation defects were depicted in greater number and conspicuity, and image quality was better with MRI.

Helen Marshall¹, Steven Thomas², Juan Parra-Robles¹, Salman Siddiqui³, Richard Kay⁴, Chris E Brightling³, and Jim M Wild^1
1Academic Radiology, University of Sheffield, Sheffield, United Kingdom, ²Medical Physics, British Columbia Cancer Agency, British Columbia, Canada, ³Institute for Lung Health, University of Leicester, United Kingdom, ⁴Novartis Pharma AG, Basel, Switzerland

Ventilation (V) and perfusion (Q) matching is essential for efficient gas exchange in the lung. Here ventilation and perfusion distributions were imaged at baseline and post-bronchodilator in 5 patients with asthma using ³He ventilation and ¹H dynamic-contrast-enhanced perfusion MRI. Maps of ventilation, peak perfusion and time-to-peak perfusion were generated and VQ distribution histograms were plotted. Individual patient VQ response to bronchodilator differed but tended towards increased and more homogeneous ventilation and perfusion post-bronchodilator. Multi-nuclear MRI provided high resolution images of regional ventilation and perfusion distributions, and was sensitive to changes in V and Q following bronchodilator administration in asthmatic patients.

Robert V Cadman¹, David G Mummy², Scott K Nagle^1,3, Nizar N Jarjour⁴, Mark L Schiebler³, Ronald L Sorkness⁵, and Sean B Fain^1,3
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, ²Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States,³Radiology, University of Wisconsin-Madison, WI, United States, ⁴Department of Medicine, University of Wisconsin-Madison, Madison, WI, United States, ⁵School of Pharmacy, University of Wisconsin-Madison, Madison, WI, United States

Although ventilation defects are a significant feature of ³He MRI images of asthmatic lungs, the relationship of those defects to clinical symptoms of asthma is not well understood. Using longitudinal ³He MRI data, ventilation defects were classified into categories based on their behavior over time. This approach will be useful in characterizing the emergence, reversal, and persistence of such defects in asthmatic patients. Further studies will investigate the relationship between emergent ventilation defects and sites of new airway injury.

Felix Horn¹, Juan Parra-Robles¹, Helen Marshall¹, Christopher Taylor², Alex Horsley³, and Jim Wild^1
1Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom, ²Sheffield Children's Hospital, Sheffield, South Yorkshire, United Kingdom, ³Adult CF Centre, University of Manchester, Manchester, United Kingdom

Previously it was shown how gas washout measured with hyperpolarized helium-3 MRI can be used to obtain quantitative regional lung function in 3D (MBW-I). Multiple breath inert gas washout as clinically performed in the pulmonary function lab (MBW) is a technique thought to be sensitive to early signs of ventilation heterogeneity in obstructive lung diseases like CF. In this preliminary work MBW-I and MBW were performed in healthy controls and CF patients. MBW-I was found to be comparable to conventional MBW, an important pre-requisite for the subsequent regional interpretation of ventilation heterogeneity.

Kun Qing¹, Kai Ruppert^1,2, Tally A. Altes¹, G. Wilson Miller¹, Yun Jiang³, Jaime F. Mata¹, Yun M. Shim¹, Chengbo Wang¹, Steven Guan¹, Iulian C. Ruset^4,5, F. William Hersman^4,5, and John P. Mugler^1
1University of Virginia, Charlottesville, VA, United States, ²Cincinnati Children's Hospital, Cincinnati, OH, United States, ³Case Western Reserve University, Cleveland, OH, United States, ⁴Xemed LLC, Durham, NH, United States, ⁵University of New Hampshire, Durham, NH, United States

As a non-invasive MR imaging method, 3-D Xe129 dissolved-phase imaging is particularly suited to monitoring functional changes of the lung and evaluating treatment efficacy for CF subjects, especially those in the pediatric population. In this study, we investigated functional changes in 5 pediatric subjects with CF, as compared with young healthy subjects. All tissue-to-gas ratio maps were inhomogeneous, interestingly, for all CF subjects imaged, the average tissue-to-gas ratios were higher in the right lung than the left lung , and most showed lower tissue-to-gas ratios in the right upper lobe as compared to the other lobes in the right lung.

Steven Guan¹, Kun Qing¹, Talissa Altes¹, John Mugler III¹, Carolina Fernandes¹, Kai Ruppert¹, Iulian Ruset^2,3, F. William Hersman^2,3, Deborah Froh¹, William Teague¹, Grady Miller¹, James Brookeman¹, and Jaime Mata^1
1University of Virginia, Charlottesville, VA, United States, ²University of New Hampshire, Durham, NH, United States, ³Xemed, LLC, Durham, NH, United States

Cystic-fibrosis (CF) is the most common, fatal, gene defect in the Caucasian population. For diseases like CF that have both obstructive and restrictive characteristics, standard pulmonary function tests can only provide a limited global assessment of ventilation parameters. 3D-Single-Breath Chemical-Shift-Imaging (3DSB-CSI) is capable of non-invasively assessing regional ventilation and multiple compartment gas uptake/exchange, which permits a better understanding of the disease and treatment efficacy. The tissue/RBC ratio maps reveal that CF subjects had a higher average tissue/RBC ratio and standard deviation, 2.96±0.74, compared to that of healthy subjects, 2.39±0.53(p=0.029). There also appears to be a good correlation (R=0.71) between the tissue/RBC ratio with the predicted FEV1. This pilot clinical study has demonstrated that 3D-SB-CSI is capable of assessing regional ventilation and multiple compartment gas uptake/exchange.

Helen Marshall¹, David Hughes², Felix Horn¹, Juan Parra-Robles¹, Alex Horsley³, Laurie Smith², Leanne Armstrong¹, Ina Aldag², Chris Taylor², and Jim M Wild^1
1Academic Radiology, University of Sheffield, Sheffield, United Kingdom, ²Sheffield Children's Hospital, Sheffield, United Kingdom, ³Manchester Adult CF Centre, University of Manchester, Manchester, United Kingdom

Early detection of lung disease is vital for effective treatment of cystic fibrosis. This study investigated the relative sensitivity of ³He ventilation MRI, ¹H anatomical MRI and CT for detection of early stage lung disease in children with mild CF. 7 CF patients with normal spirometry and 5 healthy controls were studied. Abnormalities were detected in the ³He MR and CT images of 6 patients, and the ¹H MR images of 3 patients. ³He MRI and CT provide complementary information about lung structure and function, and are more sensitive to early ventilation changes than ¹H MRI in mild CF.

Scott K Nagle^1,2, Laura C Bell², Christopher J Francois¹, Robert V Cadman², Stanley J Kruger², Andrew D Hahn², and Sean B Fain^1,2
1Radiology, University of Wisconsin, Madison, WI, United States, ²Medical Physics, University of Wisconsin, Madison, WI, United States

MRI has significant potential advantages over CT for longitudinal surveillance of cystic fibrosis (CF) with respect to reduced radiation dose, ability to image regional function, and the potential for earlier detection of disease progression or treatment response. In this study, the performance of several MRI methods for the detection of cystic fibrosis (CF) lung disease were evaluated in comparison to CT reference standards. MRI included both functional (3He ventilation and dynamic contrast-enhanced perfusion) and anatomic/structural methods, including a 3D radial ultrashort echo time (UTE) approach. There were strong correlations between CT air trapping and He-3 MRI, perfusion MRI, and UTE MRI.

OZKAN DOGANAY^1,2, MATTHEW FOX³, and GILES SANTYR^1,2
1Western University, London, Ontario, Canada, ²Robarts Research Institute, London, Ontario, Canada, ³Thunder Bay Regional Research Institute, Ontario, Canada

We present a finite element approach for modeling hyperpolarized Xenon-129 gas exchange mechanism in the lungs. The gas exchange model interprets the chemically shift saturation recovery (CSSR) spectrum with respect to different gas exchange times to reveal functional information regarding pulmonary perfusion and diffusing capacity. In particularly, the simulation provides information about changes in the pulmonary tissue and capillaries due to radiation induced lung injury by taking advantage of unique chemical shifts of dissolved hyperpolarized Xenon-129 in pulmonary tissue and red blood cells. The model may also useful for investigating other forms of lung injury (eg. Ventilator-induced lung injury).

Kai Ruppert^1,2, Kun Qing², Talissa A. Altes², Jaime F. Mata², Iulian C. Ruset^3,4, F. William Hersman^3,4, and John P. Mugler III^2
1Cincinnati Children's Hospital, Cincinnati, OH, United States, ²University of Virginia, Charlottesville, VA, United States, ³Xemed LLC, Durham, NH, United States, ⁴University of New Hampshire, Durham, NH, United States

"Chemical Shift Saturation Recovery" (CSSR) is a method for monitoring the uptake of hyperpolarized xenon-129 (HXe) by lung parenchyma. The purpose of our studies was to investigate differences in relative HXe uptake by red blood cells (RBCs) versus lung tissue and plasma (TP) in healthy subjects, asthmatics and COPD patients. We found that the RBC-to-TP ratio (RTR) for 92% of the healthy subjects fell into a narrow range. Two groups of asthmatics, one with high and one with low RTRs could be identified while all COPD patients exhibited abnormally low RTRs.

Graham Norquay¹, General Leung¹, Neil J Stewart¹, Gillian M Tozer², Jan Wolber^1,3, and Jim M Wild^1
1Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom, ²Oncology, University of Sheffield, South Yorkshire, United Kingdom, ³GE Healthcare, Amersham, Buckinghamshire, United Kingdom

In this study, the ¹²⁹Xe relaxation rate in human blood was evaluated over a large range of blood oxygenations (sO2 = 0.02 to 1.00). The ¹²⁹Xe relaxation rate (R₁) in red blood cells was found to vary linearly as a function of blood oxygenation, where the mechanism believed to be responsible is Xe interactions with paramagnetic deoxyhaemoglobin. A linear fit of ¹²⁹Xe R₁ vs the concentration of deoxyhaemoglobin ([dHb]) yielded a dHb-¹²⁹Xe relaxivity of 0.035 mM^-1s^-1. This linear relationship may be utilised in future studies involving Xe transport from the lungs to distal tissues, organs and tumours.

Hooman Hamedani¹, Stephen Kadlecek¹, Masaru Ishii², Yi Xin¹, Hoora Shaghaghi¹, Biao Han¹, Sarmad Siddiqui¹, Milton Rossman¹, and Rahim R. Rizi^1
1University of Pennsylvania, Philadelphia, PA, United States, ²Johns Hopkins University, Merryland, United States

Regional analysis of lung ventilation is facilitated through multi-breath Hyperpolarized gas (HP) MRI, a technique that quantifies the Specific Ventilation (SV) in parenchyma. This work presents the first preliminary short- and long-term variability of SV-MRI, and compares the imaging variability to that of pulmonary function tests (PFT).

Rosa Tamara Branca^1,2, Le Zhang³, and Carlos Floyd^4
1Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ²Biomedical Research Imaging Center, Chapel Hill, NC, United States,³Material Science, University of North Carolina at Chapel Hill, NC, United States, ⁴Physics and Astronomy, University of North Carolina at Chapel Hill, NC, United States

The low gyromagnetic ratio of xenon, the relatively low polarizability and concentration achievable in distal organs upon HP-129Xe gas inhalation suggest that in in vivo settings the observation of radiation damping is highly unlikely. Nonetheless we report the first observation of radiation damping effects from tissue-dissolved hyperpolarized xenon and a revision of the xenon uptake model to account for the strong local xenon uptake that leads to the observation of these effects.

Moritz C Wurnig¹, Mingming Wu², Wolfgang Jungraithmayr³, Markus Weiger⁴, Klaas P Pruessmann², and Andreas Boss^1
1Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Zurich, Switzerland, ²Institute for Biomedical Engineering, University and Swiss Federal Institute of Technology Zurich, Zurich, Zurich, Switzerland, ³Division of Thoracic Surgery, University Hospital Zurich, Zurich, Zurich, Switzerland, ⁴Institute for Biomedical Engineering, University and Swiss Federal Institute of Technology Zurich, Zurich, Zurich, Zurich, Switzerland

Magnetization transfer (MT) imaging of the lung is hampered by low spin-density and fast signal decay. Here we present our initial experience with zero echo time (ZTE) imaging with a MT preparation pulse applied for pulmonary MT imaging in-vivo. Experimental MTR values of non-pulmonary tissues obtained with ZTE showed the typical characteristics known from conventional MT sequences. Lung tissue itself showed MTR values between fatty tissue and liver-tissue. We could show that measuring MT in the lung in-vivo is feasible and that MT of lung tissue remains measurable even when large off-resonance frequencies are used to avoid direct saturation effects.

Pavla Francová^1,2, Flavio Carinci^1,2, Simon Triphan^1,3, and Peter M. Jakob^1,2
1Research Center Magnetic Resonance Bavaria e. V. (MRB), Würzburg, Germany, ²Department of Experimental Physics 5, University of Würzburg, Würzburg, Germany,³Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany

Magnetization Transfer (MT) is a promising tool for the characterization of the lung parenchyma and thus lung diseases, where e.g. the collagen content is increased. Since the mechanisms of MT in the lungs are rather unknown we investigated the influence of blood in the lung parenchyma on the MT effect. For this MTC-measurements were performed on the bloodless pig lungs and healthy volunteers group in a 1.5T scanner. The major finding was that blood has a significant influence on the MT effect.

Scott H Robertson^1,2, Suryanarayanan S Kaushik^1,3, Zackary L Cleveland^1,4, Mu He¹, Matthew S Freeman^1,2, Rohan S Virgincar^1,3, and Bastiaan Driehuys^1,4
1Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States, ²Medical Physics Graduate Program, Duke University, Durham, NC, United States, ³Department of Biomedical Engineering, Duke University, Durham, NC, United States, ⁴Department of Radiology, Duke University Medical Center, Durham, NC, United States

The 3D Radial sequence has many advantages over 2D multislice GRE, namely isotropic resolution, insensitivity to diffusion, reduced signal decay effects, and the potential for very short echo times. Despite these advantages, however, 2D multislice GRE has remained the preferred sequence for hyperpolarized lung imaging. This study applies a k-space trajectory measurement technique to a 3D radial sequence, making the 3D radial image quality comparable to that of 2D multislice GRE.

Kirill V Kovtunov¹, Milton L Truong², Aaron M Coffey², Danila A Barskiy¹, Igor V Koptyug¹, Kevin W Waddell², and Eduard Y. Chekmenev^2
1International Tomography Center, Novosibirsk, Novosibirsk, Russian Federation, ²Radiology, Vanderbilt University, Nashville, TN, United States

Fast (TR<4 ms) hyperpolarized proton MRI is presented for non-toxic propane gas prepared by heterogeneous parahydrogen induced polarization using Rh/TiO₂ solid state catalyst. 3D imaging with 0.5x0.5x0.5 mm³ is demonstrated using ~1% 1H hyperpolarized propane at 4.7 T preclinical MRI system with relatively large field of view 48x48x32 mm³. Feasibility of sub-second sub-millimeter (0.9x0.9 mm²) 2D imaging of hyperpolarized propane (polarization P=0.3%) is also demonstrated at 0.0475 T preclinical MRI using frequency optimized RF coils. Hyperpolarized propane MRI can potentially be used for economical high-throughput low-field functional MRI of human lungs.

Mingming Wu^1,2, Markus Weiger¹, Moritz Christoph Wurnig³, Wolfgang Jungraithmayr⁴, Andreas Boss³, and Klaas Paul Pruessmann^1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ²Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany, ³Department of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland, ⁴Division of Thoracic Surgery, University Hospital Zurich, Zurich, Switzerland

Pulmonary proton MRI is conducted in mice using zero echo time (ZTE) imaging. Scan times of only 81 s for a 3D image with matrix size of 160 and isotropic resolution of 0.31 mm are achieved, yielding an SNR of 8. Further improvement of image quality is accomplished using respiratory-triggering and/or averaging at the expense of higher scan times. Additionally, ZTE imaging is demonstrated to enable T1 mapping in short T2 tissue such as in the lung where a T1 value of 660 ms is found.

Oliver Bieri^1
1Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland

Only recently, a Fourier decomposition (FD) method was suggested to extract perfusion and ventilation information (parenchyma density) from a time series of co-registered 2D images. Generally, FD requires dynamic sampling with high temporal resolution and nonrigid image registration, currently limiting this technique to 2D only. Here, we introduce a simple method to visualize regional parenchyma density (ventilation) directly and in 3D using high-resolution isotropic ultra-fast balanced steady state free precession (bSSFP) scans at 1.5T acquired within a single breath-hold.

Dominique M R Corteville¹, Asmund Kjorstad¹, Frank G Zöllner¹, and Lothar R Schad^1
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Baden Württemberg, Germany

Fourier Decomposition pulmonary MRI similarly to other proton techniques suffers from a low signal to noise ratio in the lung parenchyma and would benefit from being performed at higher field strength. However the bSSFP sequence used in the standard approach is not well suited for this due to its high dependency on T2*. This submission works on improving FD MRI at higher field strength by finding a replacement for the standard sequence.

Felix Tobias Kurz¹, Thomas Kampf², Sabine Heiland¹, Martin Bendszus¹, Heinz-Peter Schlemmer³, and Christian Herbert Ziener^3
1Division of Neuroradiology, University of Heidelberg, Heidelberg, Baden-Württemberg, Germany, ²Experimental Physics 5, University of Wuerzburg, Wuerzburg, Bavaria, Germany, ³Radiology, German Cancer Research Center, Heidelberg, Baden-Württemberg, Germany

Recently, it has been shown that transverse relaxation rates for Carr-Purcell-Meiboom-Gill (CPMG) sequences in MRI are dependent on interpulse delay time in lung tissue. Here, a symmetry-bound physical model to describe alveolar structure is used within a well-known weak field approximation to provide an expression for transverse relaxation rate that is dependent on interpulse delay time, diffusion, alveolar radius and volumetric ratio of pulmonal air and blood volume. Theoretical results are in good agreement with experimental data for excised rat lung tissue and may be applied to determine in-vivo lung perfusion parameters in intravoxel incoherent motion models or to quantify structural parameters in lung micropathology.

Andrew D Hahn¹, Kevin M Johnson², Grzegorz Bauman³, Robert Cadman², Talissa A Altes⁴, and Sean B Fain^2
1Department of Medical Physics, University of Wisconsin, Madison, Madison, Wisconsin, United States, ²Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, United States, ³Department of Radiology, University of Wisconsin, Madison, Wisconsin, United States, ⁴Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Virginia, United States

Hyperpolarized helium-3 gas inhalation and exhalation dynamics were recovered with high spatiotemporal resolution in a swine model utilizing a fast 3D radial UTE MRI sequence and reconstructed using k-t PCA. This technique could provide a more robust framework for investigating functional ventilation in young children who may not be able to maintain breath hold or lay still for an extended period.

Marcus J. Couch^1,2, Iain K. Ball², Tao Li², Matthew S. Fox², Birubi Biman^3,4, and Mitchell S. Albert^1,2
1Lakehead University, Thunder Bay, Ontario, Canada, ²Thunder Bay Regional Research Institute, Thunder Bay, Ontario, Canada, ³Thunder Bay Regional Health Sciences Centre, Thunder Bay, Ontario, Canada, ⁴Northern Ontario School of Medicine, Thunder Bay, Ontario, Canada

It is well-known that pulmonary ventilation exhibits a gravitational gradient due to a gradient in regional compliance. ¹⁹F MRI, using inhaled inert fluorinated gases as a signal source, is expected to exhibit strong ventilation gradients, especially since the gas density is high. The purpose of this study was to perform ¹⁹F 3D UTE imaging in healthy volunteers, and to measure anterior/posterior ventilation gradients. This preliminary study demonstrates a clear gravitational distribution gradient of inert fluorinated gases in human lungs, and there is a potential for this technique to provide functional and regional information regarding lung physiology.

Åsmund Kjørstad¹, Dominique Corteville¹, Frank G. Zöllner¹, Thomas Henzler², and Lothar R. Schad^1
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Baden-Württemberg, Germany, ²Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Baden-Württemberg, Germany

The ventilation to perfusion ratio (V/Q) is an important physiological parameter in the lung. Recent advantages in lung MRI have shown that both the ventilation and perfusion can separately be quantified using non-invasive and non-contrast enhanced methods. To further assess the accuracy of these methods we investigate the gravitational effect of the ventilation, perfusion and the combined V/Q maps in eight healthy volunteers.

Oliver Bieri^1
1Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland

Computer tomograms show vertical gradients in parenchyma density due to gravity, relating to the mechanical properties of the lung. Gravitational effects on the lung were also assessed by a few occasional MRI studies, but are generally limited by the overall poor SNR of contemporary methods. Only recently a new ultra-fast balanced SSFP imaging technique was introduced, offering exceptional SNR and CNR for in vivo lung imaging at 1.5 T. This makes the investigation of gravity-related effects in the lung tissue feasible. Here, we develop the corresponding framework for such MRI investigations, termed MR Gravimetry of the lung.

Janet Friedrich¹, Daniel Feldmann², Maxim Terekhov¹, Claus Wagner², and Laura Maria Schreiber^1
1Department of Radiology, Johannes Gutenberg University Medical Center, Mainz, Germany, ²Institute of Aerodynamics and Flow Technology, German Aerospace Center, Göttingen, Germany

The aim of the current study was to develop a method that enables us to measure axial velocity profiles during high frequency oscillated ventilation using 19F-MRI. This work includes constant flow measurements at Reynolds numbers Re = {10 254, 15744, 21 306} and direct numerical simulations (DNS) solving the discrete Navier-Stokes equations using a finite-volume method. Measurement and simulation results were in good agreement. Flow measurements during HFOV of 4 Hz were successfully performed and show as well a good agreement with theoretical data.

Matthew S Freeman^1,2, Kiarash Emami³, and Bastiaan Driehuys^1,2
1Medical Physics Graduate Program, Duke University, Durham, NC, United States, ²Center for In Vivo Microscopy, Duke University, Durham, NC, United States, ³Polarean, Inc., Durham, NC, United States

While hyperpolarized (HP) ¹²⁹Xe MRI shows great promise as a functional imaging modality, it remains limited by HP ¹²⁹Xe polarization and production rates. Despite notable recent successes, most polarizers greatly underperform compared to theoretical predictions of the standard model of spin-exchange optical pumping (SEOP). Here we characterize 6 combinations of optical cells and lasers, and show that by postulating the generation of recently discovered paramagnetic Rb fractal clusters within the SEOP environment, observed performance can be explained. Rb fractal clusters, if confirmed, would strongly impact future polarizer designs, and if mitigated, would restore full theoretically predicted performance.

Mikayel Dabaghyan¹, Iga Muradyan², Angelos Kyriazis², Alan Hrovat¹, James P Butler², Samuel Patz², and Mirko Hrovat^1
1Mirtech Inc, Brockton, MA, United States, ²Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States

Here we present initial in vivo lung density measurements at three different lung volumes using a portable low field NMR system built in our lab. The measurements are proportional to lung density. As one predicts, the signal decreases with increasing lung volume. The measurements were highly reproducible with std < 12%. The SNR in a single 40s breath-hold at TLC was measured to be over 110. We also report initial hyperpolarized Xe measurements in a phantom using the same system with high SNR observed in a single data acquisition.

Dominik Berthel¹, Michael Neumaier², Dorothee Schüler¹, Thomas Kaulisch², Titus Lanz¹, and Detlef Stiller^2
1Rapid Biomedical GmbH, Rimpar, Germany, ²Boehringer Ingelheim Pharma GmbH & Co. KG, In-Vivo Imaging Unit, Biberach, Germany

Biomedical research studies with magnetic resonance examination of small animal lungs gaining in importance. Because of physiological limits at 1H lung-MRI ultra short echo time sequences (UTE) in combination with highly sensitive MR coils promises significant improvements. To increase the SNR factor of a phased array coil well decoupling of all elements are necessary. Moreover an anatomical shape of the array coil in respect to optimize the filling factor leads to higher SNR. We present an improved four channel phased array coil for rat lung imaging at 7T with elliptical housing which verifiably increases the SNR.

Simon Triphan^1,2, Bertram Jobst^1,3, Paul Flechsig^1,3, Felix Breuer², Peter Jakob², and Jürgen Biederer^1,4
1Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Baden-Württemberg, Germany, ²Research Centre Magnetic Resonance Bavaria e.V., Würzburg, Bayern, Germany, ³Translational Lung Research Center Heidelberg, Member of the German Lung Research Center (DZL), Heidelberg, Baden-Württemberg, Germany, ⁴German Cancer Research Center (DKFZ), Heidelberg, Baden-Württemberg, Germany

T₁, the T₁-reduction induced by breathing pure oxygen, has been used for lung functional imaging. While this effect is primarily attributed to molecular oxygen (O₂) dissolved in blood, the same also occurs in tissue. T₁ thus provides a measure of lung function comprised of various aspects. The T₁ reduction in tissue alone was examined using porcine lung explants in air and oxygen atmosphere. T₁ reductions of 12%, similar to those observed in vivo were measured. T₁ in the bloodless explants was found to be significantly shorter than in vivo. Additionally, a measurement of a preserved explant yielded even smaller T₁ and T₁.

Abdel Wahad Bidar¹, Marie Ramnegård², Rebecka Svärd², Janeli Sarv³, Sofia Tapani³, Josefin Forsberg⁴, Amir Smailagic², Thomas G. Hansson², and Johan Jirholt^2
1R&D Personalised Healthcare & Biomarkers - Imaging, AstraZeneca, Mölndal, Sweden, ²RIA Innovative medicine, AstraZeneca, Mölndal, Sweden, ³Discovery Sciences statistics, AstraZeneca, Mölndal, Sweden, ⁴DSM laboratory animal, AstraZeneca, Mölndal, Sweden

The C57BL/6J mouse strain can serve as a convenient model for investigations of immune-based therapeutics that can enhance thymic function. In this study we demonstrate for the first time in vivo by means of MRI the natural growth and involution pattern of the thymus in a group of C57BL/6J male and female mice. Male thymus involution started before mice reached 5 weeks of age and persisted up to 8 weeks. Female thymus volume reached its maximum when mice reached 6-7 weeks old and was followed by a rapid involution rate up to an age of 10 weeks.