ISMRM 23rd Annual Meeting & Exhibition • 30 May - 05 June 2015 • Toronto, Ontario, Canada

Traditional Poster Session • Body
1451 -1484 Lung/Mediastinum
1485 -1507 Hyperpolarized Gas Imaging
1508 -1538 Hepatobilliary
1539 -1586 Renal, Pelvis & Fetal
1587 -1630 Body DWI, Technical Development & Contrast

Tuesday 2 June 2015
Exhibition Hall 10:00 - 12:00

1451.   
Quantitative T1 Mapping and Oxygen Enhanced MRI in Patients with Interstitial Lung Disease
Kerry Hart1,2, Helen Marshall1, Neil Stewart1, Martin Deppe1, Steve Bianchi3, Rob Ireland2, Moira Whyte4, David Kiely3, and Jim Wild1
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom, 2Academic Unit of Clinical Oncology, University of Sheffield, Sheffield, United Kingdom, 3Pulmonary Vascular Disease Unit, Royal Hallamshire Hospital, Sheffield, United Kingdom, 4Academic Unit of Respiratory Medicine, University of Sheffield, Sheffield, United Kingdom

In patients with interstitial lung disease the interstitium becomes thickened, resulting in less efficient gas exchange. Quantitative T1 mapping was performed under normal and hyperoxic conditions in patients with idiopathic pulmonary fibrosis (IPF), patients with systemic sclerosis (SSc) and healthy volunteers. Data showed significantly reduced baseline lung T1 values in IPF and SSc compared to healthy subjects. The magnitude of oxygen induced T1 shortening in IPF was shown to be significantly smaller than in healthy subjects. Baseline lung T1 and the magnitude of T1 shortening in response to oxygen inhalation were shown to correlate with the alveolar septal thickness measured with 129Xe MRI and the diffusing capacity of the lung for carbon monoxide (DLCO).

1452.   Robust 3D MRI of the Mouse Lung Using ZTE Imaging with Background Correction
Markus Weiger1, Mingming Wu1,2, Moritz Christoph Wurnig3, David Kenkel3, Wolfgang Jungraithmayr4, Andreas Boss3, and Klaas Paul Pruessmann1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany,3Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland, 4Division of Thoracic Surgery, University Hospital Zurich, Zurich, Switzerland

Zero echo time (ZTE) imaging enables efficient 3D MRI of tissues with rapid relaxation, such as e.g. the lung. However, signal is also detected from nearby hardware parts, e.g. the RF coil, which can lead to substantial image background. Here, a subtraction method is proposed to reduce this background to a negligible level. The technique is applied to pulmonary MRI in the mouse, providing reproducible results of high quality.

1453.   Longitudinal MRI of Progressive Pulmonary Fibrosis in a Transgenic, TGF-Alpha-Induced Mouse Model
Zackary I. Cleveland1, R. Scott Dunn2, Cynthia R. Davidson3, Jinbang Guo1,4, Jason C Woods1,4, and William D. Hardie3
1Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 2Imaging Research Center, Department of Radiology, Cincinnati Children’s Hospital Medical Center, OH, United States, 3Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, OH, United States, 44) Department of Physics, Washington University, St. Louis, MO, United States

Idiopathic pulmonary fibrosis (IPF) is a poorly understood, progressive, and fatal disease. Although, mouse models are vital to IPF research, they typically provide little temporal and spatial insight, and most models fail to exhibit the non-inflammatory, progressive fibrosis seen in clinical IPF. We report the first imaging study of a non-inflammatory, progressive, transgenic mouse model that mimics key biological and temporal aspects of human IPF. In addition to noninvasively visualizing the expected pattern of fibrotic progression, this study revealed previously unknown, dynamic tissue remodeling; demonstrating that longitudinal MRI applied to relevant, preclinical models can provide novel insights into IPF biology.

1454.   Pulmonary MRI of Infants in the Neonatal Intensive Care Unit: Initial Experience with 3D Radial UTE
Andrew D. Hahn1, Nara S. Higano2,3, Laura L. Walkup2, Xuefeng Cao2,4, Robert P. Thomen2,3, Jean A. Tkach5, Charles L. Dumoulin6,7, Kevin M. Johnson1, Scott K. Nagle1,8, Jason C. Woods2,3, and Sean B. Fain1,8
1Department of Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States, 2Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States, 3Department of Physics, Washington University in St Louis, St. Louis, Missouri, United States, 4Department of Physics, University of Cincinnati, Cincinnati, Ohio, United States, 5Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States, 6Imaging Research Center - Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States, 7Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, United States, 8Department of Radiology, University of Wisconsin - Madison, Madison, Wisconsin, United States

High isotropic resolution (<1mm) MRI of lung parenchymal structure is performed in non-sedated neonatal intensive care unit (NICU) patients using a unique, 1.5T neonatal MRI system located within the CCHMC NICU and a 3-D ultra-short echo time (UTE) pulse sequence. Reconstructed images are retrospective respiratory gated to end-expiration using self-navigation properties of the center-out radial sequence. We demonstrate the ability to generate diagnostic quality images at resolution similar to computed tomography with the presented approach, and show significant improvements over previous methodology.

1455.   A double echo ultra short echo time acquisition for respiratory motion suppressed high resolution imaging of the lung
Jean Delacoste1,2, Jerome Chaptinel1,2, Catherine Beigelman1, Davide Piccini3,4, Alain Sauty5,6, and Matthias Stuber1,2
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, 2Center for Biomedical Imaging (CIBM), Lausanne, Switzerland,3Department of Radiology, Center for Biomedical Imaging (CIBM) and University Hospital (CHUV), Lausanne, Switzerland, 4Advanced Clinical Imaging Technology, Siemens Healthcare IM BM PI, Lausanne, Switzerland, 5Adult CF multisites unit, Hospital of Morges, Morges, Switzerland, 6Service of Pneumology, Department of Medicine, University Hospital (CHUV), Lausanne, Switzerland

Lung imaging presents several challenges such as blurring due to motion and short T2*. In this work, a novel method for free breathing lung imaging using an ultra short echo time sequence is demonstrated. The method uses an automated segmentation of a superior-inferior projection for respiratory motion extraction. The respiratory signal is then used to retrospectively gate the acquired data. This method was tested in 6 volunteers and lung vessel sharpness as well as blood signal to noise ratio were measured as quantitative endpoints. Motion blurring was significantly reduced in the motion-suppressed images.

1456.   Ultra-fast steady-state free precession pulse sequence for pulmonary Fourier decomposition MRI
Grzegorz Bauman1, Orso Pusterla1, and Oliver Bieri1
1Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Basel-Stadt, Switzerland

The purpose of this work is to fuse two recently introduced concepts, namely Fourier decomposition (FD) MRI and ultra-fast steady-state free precession (ufSSFP) pulse sequence for improved lung imaging in the clinical setting. We compared to the standard implementation of the FD MRI technique with the newly adapted ufSSFP sequence in healthy volunteers at 1.5T. The ufSSFP performed beneficially over bSSFP in terms of signal intensity and banding artifacts, which can be used to either increase resolution or overall image quality for ventilation- and perfusion-weighted FD images.

1457.   19F/1H MR Molecular Imaging Following Anti-angiogenic Therapy in a Translatable Preclinical Asthma Model
Anne Schmieder1, Jochen Keupp2, Huiying Zhang1, Todd Williams1, John Stacy Allen1, Xiaoxia Yang1, Erik Storrs1, Krishna Paranandi1, Elizabeth Wagner3, and Gregory Lanza1
1Washington University Medical School, St Louis, MO, United States, 2Philips Research Europe, Hamburg, Germany, 3Johns Hopkins School of Medicine, Baltimore, MD, United States

A progressive approach to asthma therapy may be to target bronchial angiogenesis in an attempt to improve pulmonary function. We have recently used high resolution, dual 19F/1H MR molecular imaging (3T) for quantifying angiogenesis in rat asthma model. Expanding on this, we used this method to noninvasively quantify the early effect of targeted antiangiogenic therapy on pulmonary neovascularization in asthma. We observed greatly diminished 19F lung signal after treatment with novel prodrug micelles, reflective of a decrease in neovascularization. This is a clinically translatable approach for noninvasive evaluation and optimization of antiangiogenic therapy in chronic airway inflammation.

1458.   Utility of T1-PETRA sequence in the evaluation of neonatal airways
Noriko Aida1, Kumiko Nozawa1, Yuta Fujii1, Mikako Enokizono1, Masahiko Sato2, Koki Kusagiri2, Yasutake Muramoto2, Yuichi Suzuki2, Jun Shibasaki3, Katsuaki Toyoshima3, Katsutoshi Murata4, and David Grodzki5
1Radiology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan, 2Radiological technology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan,3Neonatology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan, 4Research & Collaboration, Imaging &Therapy System, Siemens Japan, Tokyo, Japan, 5Magnetic Resonace, Siemens Healthcare, Erlangen, Bavaria, Germany

Clinical efficacy of prototype T1-PETRA was evaluated in 39 neonates' airway systems by rating the tracheal and three bronchial branching ([1] right upper bronchus, [2] left upper and lower bronchi, and [3] right middle and lower bronchi). In spite of babiesf breathing and motions, 135 out of 156 branching (86%) were visualized and 81(51%) were rated suitable for radiological evaluation by the consensus of two pediatric radiologists. T1-PETRA demonstrates high potential for neonatal neck and chest imaging including the airway system without radiation exposure and could be an ideal substitute for 3D-CT of the airway.

1459.   Detection of Chronic Allograft Dysfunction using Ventilation-Weighted Fourier Decomposition Lung MRI
Andreas Voskrebenzev1,2, Lena Becker1,2, Marcel Gutberlet1,2, Christian Schönfeld1,2, Julius Renne1,2, Jan Hinrichs1,2, Till Kaireit1,2, Tobias Welte2,3, Frank Wacker1,2, Jens Gottlieb2,3, and Jens Vogel-Claussen1,2
1Institute of Diagnostic and Interventional Radiology, Medical School Hanover, Hanover, Germany, 2German Centre for Lung Research, Hanover, Germany, 3Department of Pneumology, Medical School Hanover, Hanover, Germany

Survival after lung transplantation is limited by bronchiolitis obliterans syndrome (BOS). A cross-sectional study with 66 patients after double lung transplantation and 12 healthy controls was conducted to assess if ventilation-weighted Fourier Decomposition (FD)-MRI can differentiate between BOS stages. For this purpose quartile coefficient of dispersion (QCD) was calculated for each subject. The QCD increased according to the stage of disease and the Mann-Whitney U-test showed significant differences between volunteers and BOS 0 as well as between BOS 0 and BOS 1-3 patients. In conclusion, FD lung MRI is a promising tool to detect graft dysfunction due to BOS.

1460.   Self-Gating of Respiratory Motion for Pulmonary Ultra Short Echo Time MRI of Infants in the NICU
Andrew D. Hahn1, Xuefeng Cao2,3, Nara S. Higano2,4, Jean A. Tkach5, Robert P. Thomen2,4, Scott K. Nagle1,6, Gregory Lee2, Kevin M. Johnson1, Sean B. Fain1,6, and Jason C. Woods2,4
1Department of Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States, 2Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States, 3Department of Physics, University of Cincinnati, Cincinnati, Ohio, United States, 4Department of Physics, Washington University in St Louis, St. Louis, Missouri, United States, 5Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States, 6Department of Radiology, University of Wisconsin - Madison, Madison, Wisconsin, United States

The repeated sampling of the k-space center, or dc component, in 3-D center-out radial ultra short echo time (UTE) magnetic resonance imaging (MRI) can serve as a self-navigator for retrospective respiratory gating. We utilize this important feature to retrospectively reconstruct 3-D UTE pulmonary MRI at end-expiration and end-inspiration in non-sedated neonatal intensive care unit (NICU) patients, where respiratory rates, mechanical ventilation, and positioning can preclude bellows belt and pencil navigators. Gated images at end-inspiration and end-expiration provide estimates of tidal volumes and can better resolve structural abnormalities in bronchopulmonary dysplasia than ungated images.

1461.   A 19F - 1H Linear Dual Tuned RF Birdcage Coil for Rat Lung Imaging at 3T
Gowtham Gajawada1,2, Tao Li1, Marcus J Couch1,2, Matthew S Fox3,4, and Mitchell Albert1,2
1Thunder Bay Regional Research Institute, Thunder Bay, Ontario, Canada, 2Lakehead University, Thunder Bay, Ontario, Canada, 3Robarts Research Institute, London, Ontario, Canada, 4Department of Medical Biophysics, Western University, London, Ontario, Canada

An 19F-1H linear dual tuned RF birdcage coil was designed for inert fluorinated gas MRI in the lungs of rats. In order to test the homogeneity of the coil, B1 field mapping was performed in phantoms using mineral oil for the 1H channel (0°) and sulfur hexafluoride (SF6) for the 19F channel (90°). A rat was ventilated using a custom-built ventilator with a mixture of 80% SF6 and 20% O2. 1H MR images were initially acquired for localization and then 19F free breathing lung images were acquired using a 3D gradient echo.

1462.   Lung imaging at ultra-high magnetic fields in rodents
Marta Tibiletti1, Detlef Stiller2, Volker Rasche1, and Andrea Bianchi2
1Core Facility Small Animal MRI, Ulm University, Ulm, Baden-Württemberg, Germany, 2Target Discovery Research, In-vivo imaging laboratory, Boehringer Ingelheim Pharma GmbH & Co. KG, Baden-Württemberg, Germany

In this work, we demonstrate the feasibility of pre-clinical lung imaging at ultra-high magnetic fields (11.7 T) using 3D ultra-short echo time (UTE) and zero echo-time (ZTE) imaging. The results obtained at 11.7 T resulted similar with the one acquired at 7 T in comparable conditions. T2* relaxation time of lung at these magnetic fields were also calculated with a sequence of 3D UTE. ZTE images demonstrated lower SNR than UTE images, but also to be more robust to motion artifacts.

1463.   Perfluorohexane liquid MRI of mouse lungs in a dual-tuned 1H/19F coil
Alexandr A Khrapitchev1, James R Larkin1, Stavros Melemenidis1, Konstantinos Papoutsis2, Peter Thelwall3, and Nicola R Sibson1
1CRUK and MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom, 2Department of Engineering Science, University of Oxford, Oxford, United Kingdom, 3Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle, United Kingdom

The imaging of lungs with MRI is difficult owing to low proton density. Imaging with hyperpolarized noble gases has overcome some of these limitations but at great expense and effort. We have implemented imaging of mouse lungs using 19F MRI of perfluorohexane – a cheap biocompatible liquid at room temperature. Using lungs filled with perfluorohexane, we were able to obtain high resolution 2D and 3D scans with comparable SNRs to hyperpolarized xenon imaging and high resolution. These bright and stable lung images may provide a useful background for imaging contrast agents that work through production of hypointensities on T2* weighted images.

1464.   T2' relaxometry of the human lung at 1.5 and 3 Tesla
Jascha Zapp1, Sebastian Domsch1, and Lothar R. Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany

The transverse relaxation time is currently under investigation as a promising parameter for diagnosis of lung diseases. The aim of this work is to increase the precision of relaxation time measurements using a PRESS sequence. We obtained measurements with PRESS focusing on the temporal sampling of pulmonary relaxation and compared the commonly used linear exponential model for relaxation with a Gaussian model. The latter significantly reduces the relative error in relaxation time by a factor of 3 on average in the human lung. Hence, the Gaussian relaxation time is a promising parameter for investigations of lung diseases with increased precision.

1465.   In Vivo Assessment of Non-Small Cell Lung Cancer: Detection of Early Response to Concurrent Chemoradiotherapy by Using T1 Based Dynamic Contrast Enhanced MRI
Xiuli Tao1, Han Ouyang1, Li Liu1, Feng Ye1, Ying Song1, Zihua Su2, Xiao Xu2, and Ning Wu1
1Department of Diagnostic Radiology, Cancer Hospital Chinese Academy of Medical Sciences, Beijinh, Beijing, China, 2GE Healthcare, Beijing, China

We demonstrated by using T1 perfusion on lung, de-convolution based method can extract meaningful parameters to monitor concurrent chemoradiotherapy (CCRT) response of patients with non-small cell lung cancer (NSCLC). In this paper, we demonstrated by using T1 perfusion on lung, de-convolution based method can extract meaningful parameters to monitor concurrent chemoradiotherapy (CCRT) response of patients with non-small cell lung cancer (NSCLC).

1466.   Dynamic 3D MRI of the whole lung using constrained reconstruction with learned dictionaries
Sampada Bhave1, Sajan Goud Lingala2, John Newell1, Alejandro Comellas1, and Mathews Jacob1
1University of Iowa, Iowa City, Iowa, United States, 2Electrical Engineering, University of Southern California, Los Angeles, California, United States

Since MR uses non-iodizing radiation, 3D dynamic MR imaging of respiratory mechanics is a promising alternative to CT. Spirometry measurements provides only global parameters. These are often non-specific to lung diseases and also are not sensitive to detect early lung function changes since they do not provide any spatial information. Current clinical lung protocols lack the temporal resolution and slice coverage required to image the dynamics of the entire thorax. In this work, we demonstrate a rapid imaging scheme for free breathing 3D dynamic lung MRI by using dictionary learning in combination with parallel imaging and radially sampled acquisitions.

1467.   Respiratory self-gating using 3D half-echo stack-of-stars TrueFISP (TrueSTAR)
Grzegorz Bauman1 and Oliver Bieri1
1Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Basel-Stadt, Switzerland

In this work we present a retrospective respiratory self-gating technique for 3D radial hybrid stack-of-stars half-echo balanced steady-state free precession (bSSFP) sequence. The adapted radial bSSFP sequence is based on golden angle projection reordering scheme and half-echo readout. Application of very short TR was beneficial in elimination of banding artifacts known from standard bSSFP techniques, as well as for improved visualization of pulmonary vessels and tissue. We present in vivo application of the self-gated reconstruction of lung images resulting in decreased blurring and improved delineation of pulmonary structures.

1468.   Ultrashort echo time magnetic resonance imaging of the lung using a high-relaxivity T1 blood-pool contrast agent
Joris Tchouala Nofiele1, Weiran Cheng2, Inga E Haedicke2, Tameshwar Ganesh1, Xiao-an Zhang2, and Hai-Ling Margaret Cheng1,3
1Hospital for Sick Children, Toronto, Ontario, Canada, 2Chemistry, University of Toronto, Toronto, Ontario, Canada, 3Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada

The lung is one of the most challenging organs to image due to intrinsic rapid signal decay. Here we demonstrate proof-of-concept for a new MRI approach to achieve substantial gains in signal-to-noise (SNR): contrast-enhanced ultrashort echo time (UTE) imaging following intravenous injection of a high-relaxivity blood-pool manganese porphyrin T1 contrast agent. The new agent increased relative enhancement of lung parenchyma by over 10-fold compared to Gd-DTPA, and UTE boosted SNR by a factor of 4 over conventional acquisitions. The new agent maintained steady enhancement over at least 60 minutes, thus providing a long time window for obtaining high-resolution, high-quality images.

1469.   3D Ultrashort TE (UTE) MRI repeatability within the thorax and its application to pulmonary fibrosis.
Alexander Weller1, Sharon L Giles2, Veronica A Morgan2, David Collins1, David M Higgins3, and Nandita M de-Souza1
1CRUK Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom, 2MRI Department, Royal Marsden Hospital, Sutton, Surrey, United Kingdom, 3Clinical Science, Philips Healthcare, Guildford, Surrey, United Kingdom

T2* quantification within lung parenchyma using Ultra-short time to echo (UTE) MRI has previously been shown to correlate with pulmonary fibrosis in mice and CT density in humans. Here, T2* values are reported for patients with lung carcinoma, from MRI studies performed pre and post radiotherapy. Repeatability of T2* values within tumor and surrounding lung are confirmed before demonstrating: (a) T2* values for fibrotic lung and; (b) change in T2* following radiotherapy. The results reflect the potential for UTE MRI in both early identification of pulmonary fibrosis and in differentiating fibrosis from pneumonitis on CT.

1470.   Regional Measurements of Pulmonary Strain Index using a Low Field Portable Device
Mikayel Dabaghyan1, Iga Muradyan2,3, Alan Hrovat1, James P. Butler2,3, Angelos Kyriazis2,3, Mirko I. Hrovat1, and Samuel Patz2,3
1Mirtech, Inc., Boston, MA, United States, 2Brigham & Women's Hospital, Boston, MA, United States, 3Harvard Medical School, Boston, MA, United States

A portable, low field, MR Device is being designed for use in the ICU. It was tested on healthy subjects and used to measure lung density changes during a 3.5 minute breathing protocol. A regional stress index, i.e. regional lung density vs. lung volume was measured. Gravitational differences were also observed.

1471.   Can baseline T1-DCE-MRI perfusion and permeability parameters predict concurrent chemoradiotherapy response in patients of NSCLC?
Xiuli Tao1, Han Ouyang1, Li Liu1, Feng Ye1, Ying Song1, Xiao Xu2, Zihua Su2, and Ning Wu1
1Department of Diagnostic Radiology, Cancer Hospital Chinese Academy of Medical Sciences, Beijinh, Beijing, China, 2GE Healthcare, Beijing, China

DCE-MRI has been extensively used in monitoring treatment response on many anatomies. However, this technique was not fully explored in lung cancer due to breathing motion. By using a mutual information non-rigid registration method to eliminate body motion and using modified Tofts Model and de-convolution method, clinical relevant parameters could be extracted from a breath-hold DCE-MRI to monitor treatment response on NSCLC patients.

1472.   Imaging chronic rejection in mouse lung allografts with 1H MRI
Jinbang Guo1,2, Xingan Wang3, Anne K. Perl4, Zackary I. Cleveland1, Randy Giaquinto5, Andrew E. Gelman3, and Jason C. Woods1,2
1Center for Pulmonary Imaging Research, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 2Department of Physics, Washington University in St. Louis, St. Louis, MO, United States, 3Department of Surgery, Washington University in St. Louis, St. Louis, MO, United States, 4Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 5Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States

Lung transplantation is a life-saving treatment to many end-stage lung diseases, but chronic rejection remains the major barrier to the long-term survival of lung transplant recipients and is not well understood. In this study, we used triple transgenic mice (Scgb1a1/DT-A) as donors in a mouse model of orthotopic, left-lung lung transplantation to induce chronic rejection similar to that in human lung allografts. Ventilation-gated 1H MRI at 7T was performed with a 2-D short-TE GRE sequence to quantitatively monitor the rejection and relate individual outcomes with histological examination to understand the timecourse of chronic rejection.

1473.   Volumetric Non-Contrast Pulmonary Perfusion using pseudo-Continuous Arterial Spin Labeling
Joshua S. Greer1,2, Xinzeng Wang2, Ivan Pedrosa2,3, and Ananth J. Madhuranthakam2,3
1Bioengineering, UT Dallas, Dallas, TX, United States, 2Radiology, UT Southwestern, Dallas, TX, United States, 3Advanced Imaging Research Center, UT Southwestern, Dallas, TX, United States

Pulsed arterial spin labeling (PASL) techniques, such as 2D FAIRER, have been developed and evaluated in normal volunteers to study pulmonary perfusion at 1.5 T. However, PASL approaches are fundamentally limited to 2D acquisitions due to their reliance on the blood flow from outside the imaging volume, and cannot be extended to volumetric acquisitions. In this work, we present a non-contrast volumetric pulmonary perfusion using pseudo-continuous ASL labeling of the inferior vena cava in combination with a segmented 3D turbo spin echo acquisition at 3 T.

1474.   Free breathing 3D lung imaging using self-gating with an efficient sampling scheme
Cord Bastian Meyer1, Stefan Weick2, Michael Völker3, Frederick Mantel2, Felix Breuer1,3, and Peter Michael Jakob1,3
1Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany, 2Department of Radiation Oncology, University Hospital Würzburg, Würzburg, Bavaria, Germany,3Research Center Magnetic Resonance Bavaria e. V. (MRB), Würzburg, Bavaria, Germany

Examinations of the human lung under free breathing offer an increased patient comfort over those with breath holds. This increase in comfort generally comes at the cost of an increased scan time. To minimize this extra time we propose an efficient cartesian sampling scheme that employs oversampling of the k-space center. In conjunction with parallel imaging methods, artifact free volumetric images can be obtained in less than a minute.

1475.   Multi-stage three-dimensional UTE lung imaging by image-based self-gating
Marta Tibiletti1, Jan Paul2, Andrea Bianchi3, Stefan Wundrak2, Wolfgang Rottbauer2, Detlef Stiller3, and Volker Rasche1,2
1Core Facility Small Animal MRI, Ulm University, Ulm, Baden-Württemberg, Germany, 2Internal Medicine II, University Hospital Ulm, Ulm, Baden-Württemberg, Germany, 3Target Discovery Research, In-vivo imaging laboratory, Boehringer Ingelheim Pharma GmbH & Co. KG, Baden-Württemberg, Germany

In this work we combine image-based self-gating (img-SG) with ultra-short TE (UTE) 3D acquisition for lung imaging to allow effective respiratory gating during free breathing. The proposed method is also compared with k-space center self-gating (DC-SG). Successful retrospective extraction of respiratory signal from low definition, high temporal resolution images was obtained. While DC-SG signals requires to be strongly band-pass filtered which results in a sinusoidal shaped signal, img-SG permits direct visualization of the respiratory movement and therefore provides better outcome.

1476.   Breath-hold UTE Lung Imaging using a Stack-of-Spirals Acquisition
John P. Mugler, III1, Samuel W. Fielden2, Craig H. Meyer2, Talissa A. Altes1, G. Wilson Miller1, Alto Stemmer3, Josef Pfeuffer3, and Berthold Kiefer3
1Radiology & Medical Imaging, University of Virginia, Charlottesville, VA, United States, 2Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, 3Siemens Healthcare, Erlangen, Germany

The purpose of this work was to implement a breath-hold UTE acquisition based on an optimized 3D stack-of-spirals acquisition, and to perform a proof-of-concept evaluation of the method for detection of small lung nodules in three subjects with COPD, who had confirmed pulmonary nodules on CT. All nodules detected with CT (ranging from approximately 3-mm to 1-cm) were apparent on MRI. Our results suggest that the breath-hold UTE method may have potential for MR-based detection of pulmonary nodules.

1477.   Pulmonary imaging of acute lung injury in mice with ZTE
Iga Muradyan1, Raja-Elie Abdulnour2,3, Angelos Kyriazis1, Samuel Patz1, and Bruce Levy2,3
1Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States, 2Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States, 3Center for Experimental Therapeutics and Reperfusion Injury, Department of Anesthesiology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States

Zero echo time (ZTE) was used to evaluate the feasibility of performing high-resolution MRI of lung during acute inflammation, with important translational implications to evaluation of human acute lung inflammation and its resolution. Despite the presence of radial imaging artifacts, we were able to track relative signal changes in control mice compared to 24- and 72-hr post injury groups. Increased lung density at 24 hrs compared to 0 and 72 hrs is observed, which correlates with the time course of acid-induced acute lung injury, with peak airway and left lung interstitial neutrophils 24 hrs after intra-tracheal acid.

1478.   Static Lung Volumes Assessed on MRI with Spirometry Control in Comparison to Body-Plethysmography
Yanping Sun1, Christian M Lo Cascio1, Firas S Ahmed2, Meghaq A Parikh1, Yongqiang Tan2, Binsheng Zhao2, Robert C Basner1, Paul Enright3, Martin R Prince4, and R Graham Barr1
1Medicine, Columbia University Medical Center, New York, NY, United States, 2Radiology, Columbia University Medical Center, New York, NY, United States, 3Medicine, University of Arizona, Tucson, AZ, United States, 4Radiology, Cornell University Medical Center, New York, NY, United States

Lung volumes such as total lung capacity (TLC), functional residual capacity (FRC) and residual volume (RV) are used to quantify restriction, hyperinflation and gas trapping. Absolute static lung volumes are often measured using a body-plethysmograph; however, measurements are indirect, derived based upon Boyle’s Law, and can be imprecise. We tested the reproducibility of lung volumes measured directly on MRI with concomitant spirometry control and compared to body-plethysmograph measurements. TLC and RV measured by MRI met ATS/ERS criteria for reproducibility, as did TLC and FRC by plethysmography . TLC on MRI and plethysmography were highly correlated (r=0.98; P<0.001).

1479.   Ultra-short echo time MRI Measurements of Emphysema using Principal Component Analysis
Khadija Sheikh1,2, Dante Capaldi1,2, Sarah Svenningsen1,2, David G McCormack3, and Grace Parraga1,2
1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada, 2Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada, 3Division of Respirology, Department of Medicine, The University of Western Ontario, London, Ontario, Canada

Pulmonary emphysema is defined as a “progressive condition of the lung characterized by abnormal and permanent enlargement of the airspaces distal to the terminal bronchioles, accompanied by the destruction of their walls, and without obvious fibrosis”. Pulmonary emphysema has been quantified using mean signal intensity and T2* measurements enabled by ultra-short echo time (UTE) 1H MRI. We evaluated the 1H UTE frequency-signal intensity pairs to assess emphysema using principal component analysis and showed in a small group of ex-smokers with emphysema that PCA can be used to derive a UTE MRI score that is related to RA950 and FEV1/FVC.

1480.   Pulmonary Nodule/Mass Assessment by Computed Diffusion-Weighted Imaging with High b-Value: How to Improve the Detection and Differentiation Capability with Acquired Diffusion-Weighted Imaging
Hisanobu Koyama1, Yoshiharu Ohno1, Shinichiro Seki1, Takeshi Yoshikawa1, Sumiaki Matsumoto1, Katsusuke Kyotani2, Masao Yui3, Hitoshi Yamagata3, and Kazuro Sugimura1
1Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, 2Kobe University Hospital, Kobe, Hyogo, Japan, 3Toshiba Medical Systems Corporation, Otawara, Tochigi, Japan

Computed diffusion-weighted imaging (cDWI) is the newly proposed method, and this technique has been applied recently. The application of MRI to lung cancer analysis has been a relatively recent development, and assessment by means of cDWI is also expected. The purpose of this study was therefore to directly and prospectively compare capabilities for pulmonary nodule/mass detection and differentiation of malignant from benign lesions among cDWI and really acquired DWI.

1481.   How volume affects the pulmonary MRI signal: Investigations with 3D ultra-fast balanced Steady-State Free Precession
Orso Pusterla1, Oliver Bieri1, Gregor Sommer2, and Grzegorz Bauman1
1Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland, 2Clinic of Radiology and Nuclear Medicine, Department of Radiology, University of Basel Hospital, Basel, Switzerland

3D ultra-fast balanced Steady-State Free Procession imaging - originally suggested for improved morphological chest imaging and visualization of the lung parenchyma and vasculature - was used for exploring the functional dependence between the pulmonary MRI signal and the lung's volume in healthy volunteers. It is demonstrated that the signal intensity in healthy volunteers can be empirically described by a non-linear function that scales inversely proportional with the lung volume. The suggested experimental protocol may be beneficial for patients with respiratory diseases, where a distorted signal intensity dependence on the lung volume may reflect pathological changes of the lung parenchyma.

1482.   First clinical lung MRI using an Active Breathing Coordinator
Evangelia Kaza1, David J Collins1, Richard Symonds-Tayler1, Fiona McDonald2, Helen A McNair3, Erica Scurr2, Dow-Mu Koh2, and Martin O Leach1
1CR-UK Cancer Imaging Centre, Institute of Cancer Research London and Royal Marsden Hospital, London, United Kingdom, 2The Royal Marsden NHS Foundation Trust, London, United Kingdom, 3Department of Radiotherapy, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton, United Kingdom

An MR compatible Active Breathing Coordinator (ABC) system was applied for the first time for MRI of lung cancer patients using the same lung volumes and positioning as for radiotherapy planning. The morphological and functional MR images acquired under ABC control were compared with analogous CT images using radiotherapy treatment planning software. There was very good MR-CT intermodality tumour and organ position reproducibility, thus demonstrating the clinical potential of MR-ABC. Continuous MRI with simultaneous acquisition of ABC respiratory volume curves can additionally inform tumour motion tracking and Fourier Decomposition Analysis (FDA).

1483.   Clinical Feasibility of 3D Ultra-Fast Balanced Steady-State Free Precession MRI of the Lung in Patients with Severely Limited Breath-holding Capability
Gregor Sommer1, Mark Wiese2, Nicolin Hainc1, Jens Bremerich1, Oliver Bieri3, and Grzegorz Bauman3
1Clinic of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, Switzerland, 2Clinic of Thoracic Surgery, University of Basel Hospital, Basel, Switzerland, 3Clinic of Radiology and Nuclear Medicine - Radiological Physics, University of Basel Hospital, Basel, Switzerland

In this work, the clinical feasibility of 3D ultra-fast bSSFP imaging (ufSSFP) was tested in four patients with advanced pulmonary disease and severely limited breath-holding capability. In this small case series, ufSSFP MRI provided good image quality in all patients and was able to depict all relevant pathology in comparable manner to CT. In none of the datasets, diagnosis was impaired by artifacts from breathing motion. Banding artifacts, as usually seen in conventional bSSFP, were not present in any of the ufSSFP datasets. The sensitivity of this method to depict morphologic changes in particular pulmonary diseases remains to be investigated.

1484.   Proton Perfusion Maps from Time Series of the Pulmonary Vasculature
Samuel Patz1,2, Iga Muradyan1,2, Ritu R. Gill1,2, Ravi T. Seethamraju3, Aaron B. Waxman1,2, and James P. Butler1,2
1Brigham and Women's Hospital, Boston, MA, United States, 2Harvard Medical School, Boston, MA, United States, 3Siemens Medical Systems, Boston, MA, United States

Pulmonary perfusion maps were computed from a time series data set in three ways: the Fourier component, the mean, and the standard deviation. Both the mean and standard deviation images produce higher quality perfusion maps than the Fourier component method. This is explained by the high contrast between blood vessels and pulmonary parenchyma (mean) and the high harmonic content of the blood waveform (standard deviation).

Tuesday 2 June 2015
Exhibition Hall 10:00 - 12:00

1485.   Integrated Spectroscopic Imaging (CSI) and Chemical Shift Saturation Recovery (CSSR) of Hyperpolarized 129Xe in the Human Lungs
Neil James Stewart1 and Jim Michael Wild1
1Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

A method for assessment of regional changes in lung microstructure and gas-exchange with hyperpolarized 129Xe was implemented using an interleaved combination of spectroscopic imaging (CSI) and chemical shift saturation recovery (CSSR). 129Xe CSSR uptake curves demonstrated a strong anterior-posterior gradient in MR signal from dissolved and gaseous129Xe in the lung. The method was validated by measuring the anterior-posterior gradient in ventilation-perfusion ratio using the ratio of signal intensities from 129Xe in the gas phase and dissolved in erythrocytes. The proposed method may be applicable to quantify regional variations in gas-exchange dynamics in interstitial pulmonary disorders.

1486.   Hyperpolarized 129Xe Dissolved-Phase MR Spectroscopy in Mice Changes with Lung Cancer Progression
Rohan S Virgincar1, Simone Degan2,3, Matthew S Freeman4, Mu He5, and Bastiaan Driehuys3
1Biomedical Engineering, Duke University, Durham, North Carolina, United States, 2Center for Molecular and Biomolecular Imaging, Duke University, Durham, North Carolina, United States, 3Radiology, Duke University Medical Center, Durham, North Carolina, United States, 4Medical Physics Graduate Program, Duke University, Durham, North Carolina, United States, 5Electrical and Computer Engineering, Duke University, Durham, North Carolina, United States

This study exploits the solubility of 129Xe in tissues and associated chemical shifts to study pathological changes in the tissue microenvironment accompanying lung tumor formation in mice. We acquired hyperpolarized 129Xe spectra from both the FID and after a spin echo. Spin echo spectra showed two unique peaks, belonging to aqueous media and fat. The fat peak was dramatically reduced and slightly broadened with increasing tumor burden, estimated from histology. This may be a signature of white adipose tissue browning, a hallmark of cancer-associated cachexia. 129Xe MRI could thus provide a novel ionizing radiation-free tool to study cachexia.

1487.   Optimized Gridding Reconstruction for 3D Radial MRI of Hyperpolarized 129Xe
Scott H. Robertson1, Rohan S. Virgincar2, Mu He3, S. Sivaram Kaushik2, Matthew S. Freeman1, and Bastiaan Driehuys4
1Medical Physics Graduate Program, Duke University, Durham, NC, United States, 2Department of Biomedical Engineering, Duke University, Durham, NC, United States, 3Department of Electrical and Computer Engineering, Duke University, Durham, NC, United States, 4Radiology, Duke University Medical Center, Durham, NC, United States

Hyperpolarized 129Xe MRI faces well-known challenges associated with a limited, transient, and non-recoverable signal. These problems are well addressed by 3D radial acquisition, which is insensitive to magnetization dynamics, robust to undersampling, exhibits minimal gradient-induced diffusion attenuation, and achieves ultrashort TE and short TR. However, non-Cartesian reconstruction of radially acquired HP gas MRI requires careful tuning of key parameters such as the oversampling ratio, density compensation, kernel function, kernel sharpness, and kernel extent. This work explains and optimizes these aspects of non-Cartesian reconstruction for as they pertain specifically to radially acquired HP gas MRI.

1488.   Gas Uptake Measures on Hyperpolarized Xenon-129 MRI are Inversely Proportional to Lung Inflation Level
Kun Qing1, Nicholas J. Tustison1, Tallisa A. Altes1, Kai Ruppert1,2, Jaime F. Mata1, G. Wilson Miller1, Steven Guan1, Iulian C. Ruset3,4, F. William Hersman3,4, and John P. Mugler, III1
1University of Virginia, Charlottesville, VA, United States, 2Cincinnati Children's Hospital, OH, United States, 3Xemed LLC, NH, United States, 4University of New Hampshire, NH, United States

Gas uptake measures from hyperpolarized xenon-129 MRI show high sensitivity to alterations of lung function in disease. Previous studies have shown a strong dependency of these measures on lung inflation. The purpose of this study was to investigate the quantitative relationship between gas uptake measures and lung inflation level. Through experiments in 12 healthy and 5 COPD subjects, we found strong inverse relationships between gas uptake (tissue-to-gas, RBC-to-gas and total dissolved-phase-to-gas ratios) and lung inflation level. These findings could be used to obtain normalized lung function parameters that are independent of the lung inflation level at which they were measured.

1489.   In vivo dynamic measurement of pulmonary blood oxygenation and cardiac output using hyperpolarised 129Xe
Graham Norquay1, Neil Stewart1, and Jim Wild1
1University of Sheffield, Sheffield, South Yorkshire, United Kingdom

In this study, hyperpolarised (HP) 129Xe MR was used to evaluate changes in pulmonary oxygenation during breath-hold apnoea. The relationship between blood oxygenation and the129Xe-red blood cell (RBC) chemical shift was first established in vitro for in vivo chemical shift-oxygenation calibration. The 129Xe-RBC NMR signal and chemical shift (blood oxygenation) were observed to modulate with the same frequency over a breath-hold period of ~ 45 s, suggesting the possibility of using HP 129Xe MR to monitor, simultaneously, in real-time, cardiac output (from the 129Xe-RBC signal) and blood oxygenation changes (from the 129Xe-RBC chemical shift) during breath-hold apn0ea

1490.   Optimal glass forming solvent and photo-induced radicals yield 129Xe hyperpolarization via sublimation-DNP to biomedical imaging standards
Andrea Capozzi1, Christophe Roussel2, Arnaud Comment1, and Jean-Noel Hyacinthe3
1Institute of Physics of Biological Systems, EPFL, Lausanne, Vaud, Switzerland, 2Section of Chemistry and Chemical Engineering, Institute of Chemical Sciences and Engineering, EPFL, Lausanne, Vaud, Switzerland, 3University of Applied Sciences and Arts Western Switzerland, Geneva, Switzerland

Despite unique biomedical applications from ventilation to perfusion and molecular imaging, hyperpolarized (HP) 129Xe MRI suffers from the somehow limited availability of HP 129Xe. Sublimation-DNP consists in producing HP 129Xe using a generic dissolution-DNP polarizer able to produce various HP tracers. It can contribute to a wider access to HP 129Xe and spread of its unique applications. A limited polarization level was precluding the potentially higher HP gas output. In the present work we show how the combination of an optimal glass-forming solvent with photo-induced radicals leads to improved 129Xe polarization, and bring the technique to the advanced biomedical imaging standards.

1491.   129Xe Dynamic Spectroscopy and Modelling: A Repeatability and Method Comparison Study
Neil James Stewart1, Helen Marshall1, and Jim Michael Wild1
1Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

The intra-subject variability (repeatability) of quantitative parameters derived from the 129Xe chemical shift saturation recovery (CSSR) and red-blood-cell-to-tissue signal ratio (RBC-T/P) methods was evaluated to assess their sensitivity in identifying early-stage interstitial lung disease (ILD). Five healthy volunteers were scanned on three separate occasions using two implementations of the 129Xe CSSR sequence existing in literature. Intra-subject standard deviations and repeatability coefficients of CSSR-derived septal thickness and RBC-T/P ratio values were considerably less than previously-measured differences between normals and ILD patients. However, derived surface-area-to-volume ratio and capillary transit time parameters were substantially variable and cannot be considered as robust quantitative markers.

1492.   Mapping 129Xenon ADC of Radiation-Induced Lung Injury at Low Magnetic Field Strength Using a Sectoral Approach
Krzysztof Wawrzyn1,2, Alexei Ouriadov1, Elaine Hegarty1, Susannah Hickling3, and Giles Santyr1,4
1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada, 2Department of Medical Biophysics, Western University, London, Ontario, Canada, 3Department of Medical Physics, McGill University, Montreal, Quebec, Canada, 4The Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada

Early diagnosis of radiation-induced lung injury following radiotherapy is critical for prevention of permanent lung damage. MRI of the apparent diffusion coefficient (ADC) of hyperpolarized xenon-129 gas shows promise for early measurement of RILI. A UTE sequence based on a pseudo non-Cartesian k-space trajectory (i.e. Sectoral) is implemented at low field (0.07 T) for efficient use of the non-renewable magnetization of xenon-129. A pilot study demonstrated Sectoral ADC mapping on healthy and 2-weeks post irradiated rats. A significant correlation between ADC and mean linear intercept from histology was observed and a separation between the cohorts was observed with FWHM ADC.

1493.   Effect of RF Pulse Repetition Time on Gas Transfer for Dissolved Hyperpolarized 129Xe MRI
Brandon Zanette1,2, Matthew S Fox3, Ozkan Doganay3,4, Elaine Hegarty2,3, and Giles E Santyr1,2
1Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada, 2Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Ontario, Canada, 3Robarts Research Institute, London, Ontario, Canada, 4Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada

The non-renewable magnetization of hyperpolarized 129Xe gas typically allows for image acquisition to be as quick as possible. However, when imaging the dissolved phase (tissue, blood) of hyperpolarized 129Xe, signal strength is sensitive to the repetition time (TR) between RF pulses. This is due to gas transfer into the dissolved compartments and poses a problem similar to allowing for sufficient T1 recovery in conventional proton MRI. In this work we examine the effect of TR on dissolved phase 129Xe imaging and consider a simple, empirical method for determining the optimum TR which balances signal replenishment and time delay.

1494.   Regional Mapping of Gas Uptake by Lung Tissue and Blood in Subjects with COPD using Hyperpolarized Xenon-129 MRI
Kun Qing1, Talissa A. Altes1, Y. Michael Shim1, Nicholas J. Tustison1, Kai Ruppert1,2, Chengbo Wang1,3, Jaime F. Mata1, G. Wilson Miller1, Steven Guan1, Iulian C. Ruset4,5, F. William Hersman4,5, and John P. Mugler, III1
1University of Virginia, Charlottesville, VA, United States, 2Cincinnati Children's Hospital, OH, United States, 3The University of Nottingham Ningbo China, Zhejiang, China, 4Xemed LLC, NH, United States, 5University of New Hampshire, NH, United States

Hyperpolarized xenon-129 MRI is a useful tool to characterize lung function in COPD. In this study, we measured gas uptake of inhaled xenon-129 in 19 COPD subjects and 21 healthy controls, and correlated the results with xenon-129 ventilation, diffusion-weighted imaging, pulmonary function tests and exercise tolerance test. We found significant decrease of gas uptake and different patterns of functional alternations in COPD subjects as compared to healthy controls. The decrease of gas uptake appeared to be mostly correlated with emphysematous tissue destruction or enlargement of distal airways detected by xenon-129 diffusion weighted imaging, and not airflow obstruction.

1495.   Investigation of an animal model of pulmonary fibrosis - ex vivo lung MRI using a perfluorocarbon compound as a contrast agent for hyperpolarized 129Xe
Clementine Lesbats1, Anthony Habgood2, David ML Lilburn3, Joseph S Six4, Gisli Jenkins2, Galina E Pavlovskaya1, and Thomas Meersmann1
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 2School of Medicine, University of Nottingham, Nottingham, United Kingdom, 3Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, United Kingdom, 4Carestream Health Inc., White City, Oregon, United States

Gas phase hyperpolarized 129Xe imaging has been performed to compare the ventilation in control and fibrotic ex vivo lungs. The excised lungs’ blood was replaced by a perfluorocarbon fluid (PFC). Hyperpolarized 129Xe dissolved in PFC, resonating at a different chemical shift than the tissue and the gas phases, is used as a contrast agent to study the diffusion kinetics from the alveolar space, through the tissue, to the vasculature in fibrotic and control lungs. The selective destruction of the PFC signal preserves the tissue and gas phase signal, which can then provide insight into the tissue-blood diffusion properties.

1496.   T2* and Frequency Shift Maps of Healthy and CF Subjects
Steven Guan1, Kun Qing1, Tally Altes1, John Mugler III1, Iulian Ruset2,3, Deborah Froh1, Grady Miller1, James Brookeman1, and Jaime Mata1
1University of Virginia, Charlottesville, VA, United States, 2University of New Hampshire, NH, United States, 3Xemed LLC, NH, United States

Here, we present our preliminary data for comparing healthy and cystic fibrosis (CF) subjects using a robust dissolved phase fitting method for post processing Xe-129 3D Single-Breath Chemical Shift Imaging (3D SB-CSI) data. In addition to the Tissue/RBC maps, we are now able to generate peak position and T2* maps for the tissue and RBC components. Global averages for the peak positions and T2* are similar to those reported in literature. CF subjects had a lower RBC peak position than healthy subjects. Having regional analysis of these parameters presents new avenues for probing and understanding lung physiology and disease progression.

1497.   Hyperpolarized 129Xe Imaging of the Lung using Spiral IDEAL
Ozkan Doganay1,2, Trevor Wade2, Elaine Hegarty2, Krzysztof Wawrzyn2, Rolf F. Schulte3, Charles McKenzie1,2, and Giles Santyr2,4
1Western University, London, Ontario, Canada, 2Robarts Research Institute, London, Ontario, Canada, 3GE Global Research, Munich, Germany, 4Peter Gilgan Centre for Research and Learning, Toronto, Ontario, Canada

We implemented a spiral IDEAL (Iterative Decomposition of water and fat with Echo Asymmetry and Least-square estimation) approach for Hyperpolarized 129Xe Imaging of the Lung. The expected spatial resolution and SNR with respect to the readout time, Treadout, were calculated from the point spread function (PSF) and optimized for in vitro and in vivo imaging based on measured T2* values. This study shows that IDEAL-spiral approach is feasible for Hp 129Xe imaging of the rodent lung, providing an increase in normalized SNR of a factor of approximately four for the dissolved phase of Hp 129Xe in rat lungs.

1498.   Validation of 129Xe diffusion MRI as a measure of airspace enlargement in human lungs
Robert Paul Thomen1,2, James D Quirk3, David Roach1, Tiffany Egan-Rojas1, Kai Ruppert1, Iulian Ruset4, Talissa Altes5, Dmitriy Yablonskiy3, and Jason C Woods1,2
1Center for Pulmonary Imaging, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, 2Physics, Washington University in St Louis, St Louis, MO, United States,3School of Medicine, Washington University in St Louis, St Louis, MO, United States, 4XeMed, LLC, Durham, NH, United States, 5Radiology, University of Virginia Hospital Medical Center, VA, United States

3He diffusion MRI has been shown to be highly sensitive to the micro-geometry of acinar ducts and alveoli. 129Xe diffusion MRI has similar merit, despite greater technical challenges, but its utility in probing pulmonary microstructure requires validation by comparison to the gold standard of histology. Here we present the first direct comparisons of 129Xe diffusion MRI to quantitative histology in human lungs, in order to validate the imaging technique as a biomarker for airspace enlargement in COPD and take steps toward regulatory advancement. Our results show good correlation between 129Xe ADC and mean linear intercept.

1499.   Evaluation of Radiation-induced Lung Injury by Hyperpolarized Xenon
Zhiying Zhang1, Haidong Li1, Xianping Sun1, Xiuchao Zhao1, Chaohui Ye1, and Xin Zhou1
1National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei, China

Our study shows that hyperpolarized 129Xe MRI can noninvasively detect the RILI. By using the CSSR sequence and the model of xenon exchange to detect the exchange time in blood and tissue, 129Xe MRI appears to be able to quantitatively evaluate and monitor the changes of lung functions, which is in agreement with the pathological results.

1500.   Multi nuclear 3D multiple breath washout imaging with 3He and 129Xe using a dual tuned coil
Felix C Horn1, Madhwesha Rao1, Neil J Stewart1, Helen Marshall1, Juan Parra-Robles1, and Jim M Wild1
1Academic Radiology, University of Sheffield, Sheffield, United Kingdom

A recently introduced method describes 3D multiple breath washout imaging using hyperpolarized gas MRI. This preliminary study presents a methodology for multiple breath washout imaging with 129-Xe and 3-He using steady-state (bSSFP) imaging and a dual-tuned radiofrequency coil. Comparable functional information was derived from MBW-I datasets from both nuclei, with similar ventilation heterogeneity exhibited by each, despite the intrinsically different physical properties of the two nuclei. In future work, it may be possible to identify sensitivity differences in MBW-I with 3-He and 129-Xe to different physiological processes symptomatic of lung disease.

1501.   Comparing Pulmonary MRI using Inert Fluorinated Gases and Hyperpolarized 3He: Is 19F MRI Good Enough?
Marcus J. Couch1,2, Iain K. Ball2, Tao Li2, Matthew S. Fox3,4, Birubi Biman5,6, and Mitchell S. Albert1,2
1Lakehead University, Thunder Bay, Ontario, Canada, 2Thunder Bay Regional Research Institute, Thunder Bay, Ontario, Canada, 3Robarts Research Institute, London, Ontario, Canada,4Department of Medical Biophysics, Western University, London, Ontario, Canada, 5Thunder Bay Regional Health Sciences Centre, Thunder Bay, Ontario, Canada, 6Northern Ontario School of Medicine, Thunder Bay, Ontario, Canada

19F MRI of the lungs is a new pulmonary imaging modality that uses inhaled inert fluorinated gases as a signal source to acquire images of the lungs. The purpose of this study was to perform a direct comparison between inert fluorinated gas and hyperpolarized 3He MR lung imaging in the same subjects. This preliminary study demonstrates the potential of using inert fluorinated gas MRI to visualize the distribution of ventilation in human lungs, and this technique may yield meaningful functional information that is similar to hyperpolarized3He MRI.

1502.   Feasibility of hyperpolarized helium-3 MRI-guided bronchoscopic assessment of emergent ventilation defect regions in asthma
David G. Mummy1, Robert P. Thomen2, Stanley J. Kruger3, Alfonso Rodriguez3, Robert V. Cadman3, Nizar N. Jarjour4, Loren C. Denlinger4, Ronald L. Sorkness4,5, Mark L. Schiebler6, Jason C. Woods7, and Sean B. Fain3,6
1Biomedical Engineering, University of Wisconsin - Madison, Madison, WI, United States, 2Physics, Washington University in St. Louis, St. Louis, MO, United States, 3Medical Physics, University of Wisconsin - Madison, Madison, WI, United States, 4Allergy, Pulmonary & Critical Care Medicine, Department of Medicine, University of Wisconsin - Madison, Madison, WI, United States, 5Pharmacy, University of Wisconsin - Madison, Madison, WI, United States, 6Radiology, University of Wisconsin - Madison, Madison, WI, United States, 7Pediatrics, University of Cincinnati, Cincinnati, OH, United States

The progression of ventilation defects in asthma is poorly understood. Targeted longitudinal bronchoscopic sampling of lung segments exhibiting ventilation defects is of interest in characterizing physiological changes associated with defect development. Sampling that targets regions with emergent defects may detect acute local inflammatory response and changes in lung parenchyma. In this study, longitudinal hyperpolarized helium-3 MRI was used in conjunction with CT to identify regions of emergent defect in five asthma subjects. Anatomic levels of emergent defect were determined by lung segment. The results can facilitate targeted bronchoscopic sampling of ventilation defects in longitudinal studies of severe asthma.

1503.   Rapid Tracheal Flow Measurements during Forced Inhalation and Exhalation
Kai Ruppert1,2, Bora Sul3, Kun Qing2, Vineet Rakesh3, Craig H Meyer2, John P Mugler III2, Anders Wallqvist3, Michael J Morris4, Talissa A Altes2, and Jaques Reifman3
1Cincinnati Children's Hospital, Cincinnati, OH, United States, 2University of Virginia, Charlottesville, VA, United States, 3Department of Defense Biotechnology High Performance Computing Software Applications Institute, United States Army Medical Research and Materiel Command, Fort Detrick, MD, United States, 4Department of Medicine, San Antonio Military Medical Center, Fort Sam Houston, TX, United States

Attempts are underway to study airflow in the lungs using computational fluid dynamics in order to characterize disease-specific patterns. Flow-sensitive hyperpolarized-gas MRI offers a unique opportunity for experimental validation of such models in vivo. However, so far, such studies have only been performed in the slow-flow regime, which is believed to be less sensitive to pathological changes. Using interleaved-spiral acquisitions with a field-of-view only covering the trachea, we were able in this feasibility study to measure cross-sectional flow with a true temporal resolution of 150 ms and a spatial in-plane resolution of 0.8 mm during forced inspiration and expiration.

1504.   Ventilation-Perfusion Analysis with Co-registered Hyperpolarized Gas and CE 1H Perfusion MRI
Paul J.C. Hughes1, Bilal A. Tahir1,2, Felix C. Horn1, Helen Marshall1, Rob H. Ireland1,2, and James M. Wild1
1Academic Unit of Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom, 2Academic Unit of Clinical Oncology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

Multi-nuclear lung MRI can provide high spatial resolution ventilation- and perfusion-weighted images, but these are normally acquired in different RF coils with the patient moved between acquisitions such that the ventilation and perfusion images are not spatially registered. This work proposes a semi-automated image processing workflow, including registration, masking and normalisation, for quantitative assessment of V/Q, and demonstrates its utility on images acquired from patients with moderate-to-severe asthma.

1505.   Approaching the theoretical limit for 129Xe hyperpolarisation with continuous-flow spin-exchange optical pumping
Graham Norquay1, Neil Stewart1, and Jim Wild1
1University of Sheffield, Sheffield, South Yorkshire, United Kingdom

We demonstrate here experimental 129Xe polarisations of 80 %, approaching the theoretical limit of 86% predicted by our previous models, and which has been made possible by incorporation of a 50 W volume holographic grating laser diode array to a mid-pressure (2 bars) continuous-flow spin-exchange optical pumping 129Xe polariser.

1506.   Anatomical Distribution of Fractional Ventilation and Oxygen Uptake Imaged by Multibreath Wash-in Helium-3 MRI in Human Subjects
Hooman Hamedani1, Stephen Kadlecek1, Yi Xin1, Hoora Shaghaghi1, Sarmad Siddiqui1, Milton Rossman2, and Rahim R. Rizi1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, 2Medicine, University of Pennsylvania, Philadelphia, PA, United States

The suite of imaged fractional ventilation and oxygen tension may provide a useful diagnostic tool for the detection and monitoring of subclinical smoking-related alterations in lung function. Both fractional ventilation and oxygen uptake gravity gradients successfully differentiated between healthy non-smoker, asymptomatic smoker, and COPD subjects. The results in asymptomatic smokers also indicate that cigarette smoke induces changes in the lung that are not being captured by the clinical tests.

1507.   A Volume Saddle Coil for Hyperpolarized 129Xe Lung Imaging
Wolfgang Loew1, Robert Thomen2, Ron Pratt1, Zackary Cleveland2, Charles Dumoulin1, Jason Woods2, and Randy O Giaquinto1
1Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States, 2Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States

We present a design for a simply constructed, mechanically robust, and low cost MRI coil design that is suitable for routine hyperpolarized 129Xe lung imaging in both adults and pediatric subjects. To facilitate the clinical implementation of this coil design an electromagnetic model was created to evaluate B1+ homogeneity and SAR values.

Tuesday 2 June 2015
Exhibition Hall 10:00 - 12:00

1508.   Postprandial Hepatic Glycogen Levels following a Low v High Glycaemic Index Breakfast: A 13C MRS Study
S Bawden1,2, MC Stephenson3, K Hunter4, M Taylor5, L Marciani1, PG Morris2, IA Macdonald6, GP Aithal1, and PA Gowland2
1NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom, 2Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 3Agency for Science, Technology and Research, Singapore, 4Unilever Discover, Bedfordshire, United Kingdom, 5Faculty of Human Nutrition, University of Nottingham, United Kingdom, 6School of Life Sciences, University of Nottingham, United Kingdom

Natural abundance 13C MRS measurements of liver glycogen levels were acquired from 8 healthy males using a multinuclear surface coil with proton decoupling in a randomized cross over study comparing the postprandial effects of a calorie and macronutrient matched high v low glycaemic index test breakfast. The results from this study showed an immediate increase from fasted levels following both meals which began to decline from 180 minutes for the low GI meal but continued to increase for 300 minutes for the high GI meal

1509.   2D localized COSY for the quantification of omega-3 PUFA content in oil phantoms and in vivo in rat liver
Sharon Janssens1, Marina D.B. Sabbadini1, Klaas Nicolay1, and Jeanine J. Prompers1
1Biomedical NMR, Eindhoven University of Technology, Eindhoven, Noord-Brabant, Netherlands

Fatty liver disease is associated with marked changes in liver lipid composition, i.e. increases in saturated fatty acids and decreases in omega-3 polyunsaturated fatty acids (PUFA). Currently available methods to determine liver lipid composition require a biopsy. The aim of this study was to develop a 2D MRS method for in vivo detection of omega-3 PUFA based on localized correlation spectroscopy (L-COSY). We demonstrate the specific and quantitative detection of omega-3 PUFA with 2D L-COSY in oil phantoms and the feasibility to perform L-COSY in vivo in liver. However, in rat liver omega-3 PUFA content was below the detection limit.

1510.   A 7 Day Low v High Glycaemic Index Diet Reduces Liver Fat Content
S Bawden1,2, M Stephenson3, K Hunter4, M Taylor5, PG Morris2, L Marciani1, IA Macdonald6, GP Aithal1, and PA Gowland2
1NIHR Nottingham Digestive Diseases Biomedical Research Unit, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom, 2Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, 3Agency for Science, Technology and Research, Singapore, 4Unilever Discover, Bedfordshire, United Kingdom, 5Faculty of Human Nutrition, University of Nottingham, United Kingdom, 6School of Life Sciences, University of Nottingham, United Kingdom

Localized 1H MRS measurements of hepatic fat fractions were acquired from 8 healthy males in a randomized crossover study. Subjects attended test days before and after a 7 day high v low glycaemic index diet. During the test visit, subjects were scanned at baseline following an overnight fast and again 360 minutes after a test meal. Results showed that liver lipid levels were increased following the high compared to low glycaemic index diet which was sustained throughout the test day. These results may be relevant to the prevention and treatment of NAFLD.

1511.   The role of IVIM and Chemical Shift imaging in detecting early hepatic complications of Diabetes Mellitus Type 2
Sonia Isabel Goncalves1,2, Filipe Caseiro Alves2,3, and Miguel Castelo Branco1,2
1Institute for Biomedical Imaging and Life Sciences, Coimbra, Coimbra, Portugal, 2Faculty of Medicine, University of Coimbra, Coimbra, Coimbra, Portugal, 3Radiology, University Hospital Coimbra, Coimbra, Coimbra, Portugal

Diabetes Mellitus Type 2 (DM 2) has a high prevalence and appears as an important cause of morbidity and death in many countries of the western world. It has a multi-systemic scope and its chronic complications include retinopathy, neuropathy, cardiovascular disease and non-alcoholic fatty liver disease (NAFLD) . If the link between vision, neurological, cardiac complications and DM 2 has been clearly established, the association between DM 2 and NAFLD has been more recently recognized. In this work, multi-echo gradient-echo intra-voxel incoherent-motion imaging are applied to non-invasively identify staging biomarkers of NAFLD in the context of liver complications associated with Type II Diabetes Mellitus.

1512.   Oral Lipid Challenge: The Effects of Saturated Fat on Hepatic Gluconeogenesis, ATP Production, and Fat Accumulation in Healthy Humans
Paul Begovatz1, Sabine Kahl1,2, Peter Nowotny1, Bettina Nowotny1,2, and Michael Roden1,2
1Leibniz Center for Diabetes Research at Heinrich Heine University, Institute for Clinical Diabetology, German Diabetes Center, Düsseldorf, Germany, 2University Hospital, Department of Endocrinology and Diabetology, Düsseldorf, Germany

Healthy male volunteers (n=14, Age 25.6±5.3 yr, BMI of 22.5±1.1 kg/m2) ingested a 1.2±0.1 g/(kg body weight) bolus of palm oil or placebo during a 20-hr fast. 13C-MRS liver glycogen measurements revealed decreased rates of net glycogen breakdown, and increased gluconeogenesis during oil intervention compared to placebo. Palm oil intervention also led to increased rates of lipid oxidation (indirect calorimetry), and increased hepatic ATP production (31P-MRS, 3D ISIS), and liver fat (single voxel 1H-MRS). This provides evidence that a single oral bolus of saturated fat leads to increased gluconeogenesis through free fatty acid oxidation and ATP production in healthy subjects.

1513.   High SNR improves the repeatability of proton density fat fraction measurements in the liver
Utaroh Motosugi1,2, Diego Hernando1, Peter Bannas1,3, and Scott B. Reeder1,4
1Radiology, University of Wisconsin, Madison, wisconsin, United States, 2Radiology, University of Yamanashi, Yamanashi, Japan, 3Radiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany, 4Medical Physics, University of Wisconsin, Madison, wisconsin, United States

Quantitative chemical shift-encoded MRI (CSE-MRI) to quantify proton density fat fraction (PDFF) is an established and accurate imaging-based method to quantify liver fat. CSE-MRI is accurate and reproducible across different field strength and vendors. The precision of PDFF determined using test/retest measurements is approximately 3„Ÿ5 percent points. However, threshold values of ~5% are commonly used to identify clinically significant fatty liver disease, requiring improved precision. In this study, we demonstrate that high SNR acquisition obtained through a decrease in spatial resolution provides significantly improved repeatability (precision) for PDFF measurements in the liver.

1514.   Evaluation of novel multi echo MRS and MRI sequences for iron and fat overload quantification at 3T in one breath-hold
Anita Kiani1, Elise Bannier1, Giulio Gambarota2,3, Hervé Saint-Jalmes2,3, and Yves Gandon1
1Radiology, University Hospital of Rennes, Rennes, France, 2INSERM, UMR 1099, Rennes, France, 3Université de Rennes 1, LTSI, Rennes, France

 
The aim of the study was to assess and compare multiecho MRS and 3D VIBE multiecho MRI sequences at 3T for the quantification of liver iron and fat overload.

1515.   Effect of gadolinum on hepatic fat quantification using multi-echo reconstruction technique with T2* correction and estimation
MINGMEI GE1, JING ZHANG2, ZIHENG ZHANG2, and XINHUAI WU1
1The Military General Hospital of Beijing PLA, Beijing, Beijing, China, 2GE Healthcare China, Beijing, China

The purpose of this study is to determine whether IDEAL IQ fat quantification in liver is affected by administration of gadolinum. The results demonstrated that IDEAL IQ fat quantification remains stable after gadolinum administration. Therefore, the fat fraction measurement could be performed after the CM administration as the backup for the occasionally failed pre-contrast acquisition, and more importantly it could be purposely designed so to optimize the MR imaging protocols of abdomen and substantially improve the efficiency of the clinical exam.

1516.   Feasibility of MR Elastography of the Liver in Obese Patients at Risk for NAFLD
Curtis N Wiens1, Alan B McMillan1, Nathan S Artz1,2, Rashmi Agni3, Nikolaus Szeverenyi4, William Haufe4, Catherine Hooker4, Meng Yin5, Guilherme M Campos6, Claude Sirlin4, and Scott B Reeder1,7
1Department of Radiology, University of Wisconsin, Madison, Wisconsin, United States, 2Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, United States, 3Department of Pathology, University of Wisconsin, Madison, Wisconsin, United States, 4Department of Radiology, University of California, San Diego, California, United States, 5Department of Radiology, Mayo Clinic, Rochester, Minnesota, United States, 6Department of Surgery, University of Wisconsin, Madison, Wisconsin, United States, 7Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, United States

This study demonstrated feasibility of hepatic MR elastography (MRE) in obese patients. 54 patients (BMI: 45±6 kg/m2) undergoing bariatric surgery were recruited for a hepatic MR examination including MRE and fat quantification. Hepatic stiffness measurements from MRE were compared to fibrosis stage obtained from intraoperative liver biopsies. The tech-nical success rate of MRE in this population was 81%. MRE quality was adversely affected by greater subcutaneous adi-pose tissue thickness, smaller voxel size, and greater hepatic fat fraction.

1517.   Dual echo, PDFF and mDIXON compared to 1H-MRS for fat fraction estimation: only PDFF can accurately measure low fat fractions.
Jurgen Henk Runge1, Ulrich H Beuers2, Aart J Nederveen1, and Jaap Stoker1
1Radiology, Academic Medical Center, Amsterdam, Noord-Holland, Netherlands, 2Gastroenterology & Hepatology, Academic Medical Center, Amsterdam, Noord-Holland, Netherlands

Accurate and reproducible liver fat fraction (FF) estimation is important. 1H-MRS is the MR reference standard but has certain drawbacks, some of which are resolved by imaging-based FF estimation. The standard mDIXON acquisition allows high-resolution water (W) and (F) image reconstruction, but its FA and short TR, induce T1-weighting, causing over-estimation of low FF. We compared dual echo, mDIXON and proton density fat fraction (PDFF) with 1H-MRS in fatty liver disease patients. mDIXON had non-zero lower limit, i.e. over-estimation of low FF: standard mDIXON images should not be used for FF mapping. PDFF compared best to 1H-MRS and is preferable.

1518.   Effect of Gd-EOB-DTPA on T1-weighted dual echo In-phase and opposed-phase MR images for focal liver lesion detection
Jin Wang1, Lin Luo2, Yunhong Shu3, Hong Shan1, and Bingjun He1
1The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China, 2The University of Hong Kong-Shenzhen Hospital, Guangdong, China, 3Mayo Clinic, Minnesota, United States

The T1-weighted, dual gradient-echo in-phase /opposed-phase imaging sequence has become a routine part of every hepatic MR imaging protocol. It is a helpful tool to detect focal liver lesions. This sequence is conventionally performed before contrast injection. Gd-EOB-DTPA is a FDA approved liver-specific gadolinium compound. When Gd-EOB-DTPA is used, hepatic-phase imaging can be acquired ~20 minutes after the injection. To streamline the overall protocol, it is desirable to move the dual echo sequence from pre-contrast to post-contrast. The aim of this study is to compare dual-echo data pre and post contrast and evaluate its effect in detecting focal liver lesions

1519.   Effect of conventional gadolinium contrast agents on IDEAL based hepatic fat-fraction measurements
Florine SW van der Wolf - de Lijster1, Andrew J Patterson1, Martin J Graves1, and David J Lomas1
1Department of Radiology, Addenbrooke's Hospital and University of Cambridge, Cambridge, United Kingdom

22 patients were imaged using a chemical-shift encoded water-fat MRI sequence (IDEAL-IQ) on 1.5T with a low flip angle (8 degrees), before and after administration of a conventional gadolinium-based contrast agent. Hepatic fat fraction (HFF) was measured by drawing 5 ROI’s per liver on pre-gadolinium images, which were copied to matching locations of the post-gadolinium images. Results: HFF values were not significantly influenced by administration of gadolinium. This allows for examination time reduction by performing the HFF acquisition in the interval between dynamic and delayed phase imaging post-gadolinium.

1520.   Intravoxel incoherent motion diffusion-weighted imaging and texture heterogeneity for staging of hepatic fibrosis in children
WEIMIN AN1, JING ZHANG2, and HUI XIE1
1department of radiology, 302 military hospital of china, Beijing, Beijing, China, 2GE Healthcare China, Beijing, China

Diffusion weighted imaging (DWI) has been used to assess liver fibrosis by mean apparent diffusion coefficient values in liver parenchyma. However, fibrotic distribution in the liver is progressive and uneven, and the ADC value can be influenced by true molecular diffusion in a solid tissue and microcirculation in vessels , which limit the general utility of conventional DWI. With the advent of intravoxel incoherent motion (IVIM) mode, perfusion-related diffusivity and pure molecular diffusivity could be generalized simultaneously. We therefore assessed performance of IVIM DWI parameters and corresponding coefficients of variation (CVs) for liver fibrotic staging and texture heterogeneity analysis in children.

1521.   Inter-observer Agreement of Liver Biopsy and Liver MR Elastography
Jun Chen1, Meng Yin1, Jayant Talwalkar1, Kevin Glaser1, Thomas Smyrk1, and Richard Ehman1
1Mayo Clinic, Rochester, MN, United States

Although invasive, liver biopsy has been regarded as the reference method for liver fibrosis diagnosis. Liver MR Elastography is a noninvasive method for liver fibrosis diagnosis. In this study, we compared the inter-observer agreement of two biopsy interpretations with that of two liver MRE interpretations. We found that liver MRE had greater inter-observer agreement than liver biopsy, MRE_ICC = 9544, Biopsy_ICC = 0.8858.

1522.   Evaluation of Liver Stiffness in Constrictive Pericarditis
Bogdan Dzyubak1, Eric R. Fenstad2, Jae K. Oh1, Eric E. Williamson1, James Glockner1, Phillip M. Young1, Richard L. Ehman1, Philip A. Araoz1, and Sudhakar K. Venkatesh1
1Radiology, Mayo Clinic, Rochester, Minnesota, United States, 2Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, United States

Constrictive pericarditis (CP) can cause liver failure via chronic passive venous congestion. Liver biopsy in CP is avoided due to increased risk of hemorrhage. There is a need for non-invasive method for assessment of liver with CP. In this prospective study of 16 patients, hepatic stiffnesses were measured with liver MRE performed in the same session as cardiac MRI. A significant correlation of liver stiffness with right atrial pressure was shown. Furthermore, patients with CP had a significantly (p<0.05) elevated hepatic stiffness compared to those without. Additional investigation into the diagnostic value of liver stiffness in CP is warranted.

1523.   Revisiting the potential of alternating repetition time balanced steady state free precession imaging in the abdomen at 3T
Oliver J. Gurney-Champion1,2, Remy Klaassen3,4, Jaap Stoker1, Arjan Bel2, Hanneke W.M. van Laarhoven3, Aart J. Nederveen1, and Sonia I. Goncalves5
1Radiology, Academic Medical Center, Amsterdam, Netherlands, 2Radiation Oncology, Academic Medical Center, Amsterdam, Netherlands, 3Department of Medical Oncology, Academic Medical Center, Amsterdam, Netherlands, 4Laboratory for Experimental Oncology and Radiobiology, Academic Medical Center, Amsterdam, Netherlands, 5Institute for Biomedical Imaging and Life Sciences, University of Coimbra, Coimbra, Portugal

In this work we optimize ATR-bSSFP with respect to contrast and fat saturation for abdominal imaging. To do so we used simulations and validated them with phantom measurements. After validation, we use the simulations to determine optimal settings with respect to contrast between abdominal organs. We then confirm the optimal contrast settings in vivo in two healthy volunteers and a patient with pancreatic cancer.

1524.   Comparison of Navigated DISCO Dynamic Imaging with Rotated Slab Excitation to Current Standard for Post- Contrast Imaging in Pediatric MR Enterography
Dean Kolnick1, Kang Wang2, Andrew Phelps1, Pauline Worters2, John Mackenzie1, and Jesse Courtier1
1Department of radiology and biomedical imaging, UCSF, San Francisco, California, United States, 2GE Healthcare, CA, United States

In this study we examine the use of a 4D Dynamic imaging (4DDi) with rotated slab execution (ROSE) MRI sequence versus the current standard in order to overcome the limitations of Pediatric MR Enterography.

1525.   Comparison of CAIPIRINHA-VIBE, Radial-VIBE, and conventional VIBE for free-breathing dynamic contrast-enhanced MRI (DCE-MRI): a preliminary study
Nieun Seo1, Seong Joon Park1, Bohyun Kim1, Chang Kyung Lee1, Jisuk Park1, In Seong Kim2, and Berthold Kiefer3
1Asan Medical Center, Ulsan University College of Medicine, Seoul, Korea, 2Siemens Healthcare, Seoul, Korea, 3Siemens Healthcare, Erlangen, Germany

Dynamic contrast-enhanced (DCE)-MRI has emerged as an important method for evaluating tumor blood flow and treatment response to antivascular agents. However, it is difficult to acquire good DCE-MRI of abdomen or thorax due to the respiratory motion. To overcome the respiratory motion artifact, we evaluated the feasibility of free-breathing dynamic contrast-enhanced MRI (DCE-MRI) of the abdomen and thorax at 3.0 T using CAIPIRINHA-VIBE and radial VIBE with KWIC reconstruction. Our results showed that they can overcome respiratory motion while providing high spatial and temporal resolution.

1526.   
Simultaneous Acquisition Sequence for High Accuracy Whole Liver Perfusion Quantification(SAHA)
Jia Ning1, Bida Zhang2, Honsum Li1, Dan Zhu1, Feng Huang2, Shuo Chen1, Peter Koken3, Jouke Smink4, and Huijun Chen1
1Center for Biomedical Imaging Research, Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, 2Philips Research China, Beijing, China, 3Innovative Technologies, Research Laboratories, Philips Technologie GmbH, Hamburg, Germany, 4Philips Healthcare, MR Clinical Science, Best, Netherlands

Dynamic contrasted enhanced (DCE) MR imaging combined with pharmacokinetic modeling, which can quantify the perfusion and permeability of capillary in liver, is an important technique in diagnosis for malignancy detection, fibrosis stage estimation and hepatic function evaluation [1]. DCE-MRI of liver requires high temporal resolution for accurate arterial input function (AIF) and portal venous input function (VIF). On the other hand, high spatial resolution is also important small lesion detection. However, it is hard to achieve both high temporal resolution and spatial resolution at the same time with enough SNR and coverage for whole liver imaging. In this study, considering the AIF&VIF are fast changing while the intensity of hepatic parenchyma is slowly evolved, we propose a new DCE acquisition method to acquire two 2D acquisitions for high temporal resolution AIF and VIF, and a 3D acquisition for high spatial resolution whole liver imaging, simultaneously. In this interleaved acquisition scheme, the proposed sequence can improve the accuracy of pharmacokinetic analysis.

1527.   Distinguishing early and progressed HCC using texture analysis using gadoxetic acid-enhanced hepatobiliary phase image
Morisaka Hiroyuki1, Utaro Motosugi1,2, Shintaro Ichikawa1, Katsuhiro Sano1, Tomoaki Ichikawa1, Masayuki Nakano3, and Hiroshi Onishi1
1Department of Radiology, University of Yamanashi, Chuo, Yamanashi, Japan, 2Department of Radiology, University of Wisconsin, Madison, WI, United States, 3Department of Pathology, Shonan Fujisawa Tokushukai Hospital, Kanagawa, Japan

A texture may carry substantial information about the structure of physical objects in medical images, while radiologists usually assess texture only qualitatively as image interpretation. It is important to distinguish early and progressed HCC, since therapeutic strategies are completely different. Theoretically early HCC can remain a little uptake ability of gadoxetic acid, which implies texture analysis of gadoxetic-acid enhanced hepatocyte phase image can be useful for the differentiation between early and progressed HCCs. In this study, we found texture analysis may have additional role for this purpose.

1528.   Hypoenhancing liver lesion on both portovenous and delayed phase gadobutrol and gadofosveset-enhanced MRI as a sign of malignancy in the diagnosis of colorectal liver metastases (CRLM)
Helen Cheung1, Paul Karanicolas2, Chirag Patel1, Natalie Coburn2, Masoom A Haider1, Calvin Law2, and Laurent Milot1
1Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 2Surgery, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

Accurate diagnosis of colorectal liver metastases (CRLM) is a common and important clinical problem. Classically, CRLM appear hypoenhancing on portovenous and delayed phases with dynamic contrast enhanced MRI using extracellular contrast agents (eg. gadobutrol). These CRLM tend to be easy to diagnose because benign lesions rarely demonstrate this sign. However, some CRLM will not follow this pattern and can be difficult to diagnose. We hypothesize that more lesions will demonstrate this sign with intravascular contrast agents (eg. gadofosveset) leading to improved diagnosis. With gadofosveset, 26% more lesions demonstrated this sign than with gadobutrol, resulting in improved sensitivity (65% to 90%).

1529.   Prospect of hypovascular hepatocellular nodules showing hyper-intensity only in the hepatobiliary phase of Gd-EOB-DPTA enhanced magnetic resonance imaging in cirrhosis or chronic hepatitis
Atsushi Higaki1, Tsutomu Tamada1, Akira Yamamoto1, Yasufumi Noda1, Kazuya Yasokawa1, and Katsuyoshi Ito1
1Radiology, Kawasaki Medical School, Kurashiki city, Okayama, Japan

The aim of this study was to evaluate the outcomes of small hypovascular nodules detected on only hepatobiliary phase of Gd-EOB-DTPA enhanced MR imaging as hyper-intensity. In this study, none of the nodules showed hypervascularization during follow-up periods, and most of these nodules did not show the increase in size. Therefore, our results suggested that small hypovascular hepatocellular nodules showing hyper-intensity only in the hepatobiliary phase of Gd-EOB-DPTA enhanced MR imaging without increase in size in patients with chronic liver disease might be observable lesions with clinical benignity.

1530.   Phospholipidosis affects Hepatobiliary Function as assessed by Gadoxetate DCE-MRI
Stephen Lenhard1, Debra Paul2, Mally Lev3, Lindsey Webster4, Christopher Goulbourne5, Richard Peterson5, Richard Miller6, and Beat Jucker1
1Pre-clinical and Translational Imaging, GlaxoSmithKline, King of Prussia, Pennsylvania, United States, 2LAS, GlaxoSmithKline, King of Prussia, Pennsylvania, United States, 3DMPK, GlaxoSmithKline, King of Prussia, Pennsylvania, United States, 4DMPK, GlaxoSmithKline, Research Triangle Park, North Carolina, United States, 5Safety Assesment, GlaxoSmithKline, Research Triangle Park, North Carolina, United States, 6LAS, GlaxoSmithKline, Research Triangle Park, North Carolina, 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) we performed hepatobiliary Dynamic Contrast Enhanced MRI (DCE-MRI) to determine if Gadoxetate kinetic changes could be detected with a known inducer of hepatic PLD (Amiodarone). Amiodarone induced a significant decrease in Gadoxetate washout rate which returned to baseline levels after the 2 week washout of Amiodarone. Gadoxetate DCE MRI of liver function may be a useful technique to assess hepatic functional consequences of PLD for compounds found to induce PLD.

1531.   Efficient fat suppression by slice-selection gradient reversal in stimulated echo diffusion weighted liver imaging
Hui Zhang1, Ed X. Wu2,3, and Hua Guo1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, 2Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China, 3Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China

Since Single-shot echo planar imaging (EPI) is sensitive to chemical-shift artifacts and there are higher inhomogeneity at 3T, fat suppression become especially challenging for traditional methods on the liver at 3T. Therefore it is very difficult to do the study about the diffusion time effect on liver diffusion measurements. To solve this, another much more efficient method, slice-selection gradient reversal (SSGR), was incorporated into stimulated echo (STE) diffusion weighted imaging sequence. In vivo results show that SSGR are combined with STE successfully and can suppress the fat signal much more efficiently than traditional methods.

1532.   Correlation of histological and IVIM-derived measures of vascularity in hypo- and hypervascularized pancreatic lesions
Miriam Klauss1, Philipp Mayer1, Klaus Maier-Hein2, Frank Bergmann3, Thilo Hackert4, Lars Grenacher1, and Bram Stieltjes5
1Diagnostic and Interventional Radiology, University hospital Heidelberg, Heidelberg, Baden-Württemberg, Germany, 2DKFZ, Heidelberg, Baden-Württemberg, Germany, 3Pathology, University of Heidelberg, Baden-Württemberg, Germany, 4Surgery, University hospital Heidelberg, Baden-Württemberg, Germany, 5Radiology, University hospital Basel, Basel, Switzerland

This study evaluated the correlation between IVIM-derived parameters and histologically determined vascular density (MVD) in hypo- and hypervascular solid pancreatic carcinomas. 42 patients underwent DWI-MRI with eight b-values. IVIM-parameters were extracted from VOIs, MVD was determined histologically and Pearson-correlation-coefficients were calculated between the parameters. f and MVD showed excellent correlation (r=0.85), D and D* did not correlate. This is the first study showing a histological correlation between the IVIM-derived perfusion fraction f and the microvessel density in hypo- and hypervascular solid pancreatic tumors. Therefore, IVIM DWI imaging may serve as noninvasive marker of tumor vascularity in pancreatic cancer.

1533.   Navigated 3D MRCP with Compressed Sensing
Scott A Reid1, Kevin F King2, Florine van der Wolf-de Lijster3, Martin J Graves3, Lloyd Estkowski2, and David J Lomas3
1GE Healthcare, Chalfont St Giles, United Kingdom, 2GE Healthcare, Waukesha, Wisconsin, United States, 3Radiology, Addenbrooke's Hospital & University of Cambridge, Cambridge, Cambridgeshire, United Kingdom

3D MRCP scans can be as long as 4-5 minutes long, during which time physiological motion artefact may result in reduced image quality. Here we developed a Navigated 3D MRCP sequence with compressed sensing to allow a reduced acquisition time. The results from 7 volunteers shows that the MRCP with CS produced good quality images similar to the standard sequence, however, with the CS the acquisition time was reduced by around 50%. Therefore we conclude that the use of CS with MRCP has the potential to reduce motion related artefacts and improve workflow efficiency

1534.   Use of enhanced T2 star-weighted angiography (ESWAN) to distinguish severity of liver cirrhosis
CHUNMEI MA1, Ailian Liu1, YE LI1, LIHUA CHEN1, and HEQING WANG1
1The first affiliated hospital of Dalian medical university, Dalian, Liaoning, China

Chronic liver disease causes iron deposition such as liver cirrhosis.Because iron is paramagnetic, when iron deposition increases, the uniformity of the local magnetic field changes to various degrees depending on the content of the iron deposition. Thus, iron deposition can result in an increase in susceptibility effects, thereby affecting the T2∗relaxation time and R2* value.Resently, a novel MRI sequence, enhanced susceptibility weighted angiography (ESWAN), has been widely used in clinical practice .The aim of this study was to investigate the interrelation between hepatic Iron deposition and liver function in patients with liver cirrhosis by means of enhanced T2 star-weighted angiography (ESWAN).

1535.   T1lower case Greek rho relaxation of the liver; Comparison of the continuous wave and stretched type adiabatic hyperbolic scant (HS) pulses for the assessment of liver function
Yukihisa Takayama1, Akihiro Nishie2, Yoshiki Asayama2, Kousei Ishigami2, Yasuhiro Ushijima2, Daisuke Okamoto2, Nobuhiro Fujita2, Koichiro Morita2, Tomoyuki Okuaki3, and Hiroshi Honda2
1Department of Radiology Informatics and Network, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Fukuoka, Japan, 2Department of Clinical Radiology, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Japan, 3Philips Healthcare APAC, Tokyo, Japan

Image quality and diagnostic capability to assess liver function of T1ρ map were compared among three different methods: continuous wave pulse(CW), stretched type adiabatic heperbolic scant 8(HS8) pulse with pulse duration of 5ms(adiabatic-HS8-5) and adiabatic-HS8 pulse with pulse duration of 10ms(adiabatic-HS8-10). There was no significant difference in image quality scores between adiabatic-HS8-5 and adiabatic-HS8-10, but both showed significantly higher scores comparing with CW-T1ρ(p<0.05). Regarding the assessment of liver function, CW showed the highest correlation coefficient between T1ρ relaxation and ICG-R15 among three methods. Two adiabatic-HS8-5 pulses allowed generating homogeneous T1ρ maps, but CW was more advantageous to assess liver function.

1536.   The Prevalence and Natural history of Pancreatic cysts in Autosomal Dominant Polycystic Kidney Disease
Jin Ah Kim1, Jon D. Blumenfeld2,3, Silvina P. Dutruel1, Nanda Deepa Thimmappa Deepa Thimmappa1, Warren O. Bobb2, Stephanie Donahue2, Ashley E. Giambre4, and Martin R. Prince1
1Radiology, Weill Cornell Medical College, New York, New York, United States, 2The Rogosin Institute, New York, United States, 3Medicine, Weill Cornell Medical College, New York, United States, 4Healthcare Policy and Research, Weill Cornell Medical College, New York, United States

There has been only few studies on pancreatic cysts in ADPKD. This study is to determine the prevalence and the natural history of pancreatic cysts in ADPKD using MRI and age, gender, race and renal function matched controls.

1537.   Aortic Pulse Wave Velocity Measured using4D-Flow MRI in Patients with Portal Hypertension
Matthew R. Smith1, Alejandro Roldan-Alzate1, Oliver Wieben1,2, Scott B. Reeder1,2, and Christopher J. Francois1
1Radiology, University of Wisconsin, Madison, WI, United States, 2Medical Physics, University of Wisconsin, Madison, WI, United States

Diffuse liver disease, such as non-alcoholic fatty liver disease (NAFLD), causes a generalizedpro-inflammatory response that leads to increased risk of cardiovascular disease. Aortic pulse wave velocity (PWV) is a biomarker of vascular stiffeningthat can indicate increased cardiovascular risk.We therefore hypothesized that aortic PWV would be elevated in the setting of cirrhosis and portal hypertension. 4D flow MRI was performed at 3T in 11 patients with portal hypertension and 13 healthy controls. Aortic PWV was calculated using the time-to-foot (TTF) method and demonstrated statistically significant differences between the two groups.

1538.   Accelated non-contrast-enhanced MR portography with undersampled k-space using compressed sensing reconstruction
Hiroyoshi Isoda1, Koji Fujimoto1, Shigeki Arizono:1, Akihiro Furuta1, Takayuki Yamamoto1, Yasutaka Fushimi1, Aki Kido1, Kaori Togashi1, and Naotaka Sakashita2
1Kyoto University Graduate School of Medicine, Kyoto, Kyoto, Japan, 2Toshiba Medical Systems Corporation MRI Systems Division, Otawara, Tochigi, Japan

Shortening of the acquisition time is feasible using compressed sensing (CS) which is a method of image reconstruction from undersampled data. The aim of this study was to compare and evaluate images of non-contrast-enhanced MR portography with two different methods, fully sampled k–space data and undersampled k-space using CS. Shortening the acquisition time for portal vein visualization was feasible without deterioration of the image quality by CS method at undersampling a factor of 3.7. It will facilitate using non-contrast-enhanced MR porography with CS method in clinical practice.

Tuesday 2 June 2015
Exhibition Hall 10:00 - 12:00

1539.   Preliminary application of diffusion kurtosis imaging in the diagnosis of prostate cancer
Jing Guo-dong1, Wang Li2, Wang Jian2, and LU Jian-ping2
1Chang Hai Hospital, Shang Hai, Shang Hai, China, 2Chang Hai Hospital, Shang Hai, China

Prostate cancer is the second most frequently diagnosed cancer and the sixth leading cause of cancer death in men.And MRI is a useful tool in detection and management of prostate cancer.It can be argued that among various functional MR imaging techniques available, diffusion-weighted (DW) imaging currently shows the greatest potential to become accepted and applied as a useful clinical diagnostic approach for prostate cancer.

1540.   High-Resolution Computed DWI with High b-Value: A Preliminary Study for Improving Prostate Cancer Detection at 3T MR System
Yoshiko Ueno1, Satoru Takahashi2, Yoshiharu Ohno2,3, Katsusuke Kyotani4, Masao Yui5, Yoshimori kassai5, Kazuhiro Kitajima6, and Kazuro Sugimura1
1Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, 2Department of Radiology, Kobe University Graduate School of Medicine, Hyogo, Japan, 3Advanced Biomedical Imaging Research, Kobe University Graduate School of Medicine, Hyogo, Japan, 4Division of Radiology, Kobe University Hospital, Hyogo, Japan, 5MRI Systems Development Department, Toshiba Medical Systems Corp, Tochigi, Japan, 6Department of Radiology, Hyogo College of Medicine, Hyogo, Japan

Computed diffusion weighted imaging (cDWI) is proposed as a new technique that produces any b-value images from acquired DWI (aDWI) with at least two different b-values. Recently, high-resolution DWI of the prostate had potential for improving the sensitivity to small or sparse prostatic cancer (PCa). Thus, our aim was to determine the influence of voxel size to cDWI with high b value, and directly compare image quality and capability for PCa detection with aDWI with high b-value as obtained conventional and reduced voxel sizes at 3T MR system.

1541.   Multi-b-value diffusion weighted imaging acquired on a 3T MR scanner: comparison of the apparent diffusion coefficient in prostate cancer detection and the contribution of b-value images in ADC map interpretation.
Thomas de Perrot1, Bénédicte M A Delattre1, Lindsey A Crowe1, Iris Friedli1, Marc Pusztaszeri2, Jean-Christophe Tille2, Christophe Iselin3, and Jean-Paul Vallée1
1Division of Radiology, Geneva University Hospital, Geneva, Switzerland, 2Division of Clinical Pathology, Geneva University Hospital, Geneva, Switzerland, 3Division of Urologic Surgery, Geneva University Hospital, Geneva, Switzerland

We examined the influence of b-value on ADC map performance for prostate cancer in a retrospective study. We have demonstrated that the flow-sensitive ADC map was superior to the flow-insensitive ADC map for prostate cancer detection and that multi-b ADC maps in comparison with a 2-b ADC map did not improve detection. In addition, b-value images provide complementary information and improve over the ADC map alone in cancer detection. This study provides a statistical demonstration of the commonly accepted practice to look for enhanced signal in cancer on the high b-values images in the area of reduced ADC.

1542.   Characterisation of Placental Diffusion in Twin Pregnancies using Diffusion-Weighted Magnetic Resonance Imaging
Soha Said Ramadan1, Pablo Caro Dominguez1,2, Jorge H. Davila1,2, Melissa Valdez Quintana1,2, Julie Hurteau-Miller1,2, David Grynspan2,3, Felipe Moretti2,4, and Elka Miller1,2
1Department of Radiology, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada, 2Department of Diagnostic Imaging, University of Ottawa, Ottawa, Ontario, Canada,3Department of Pathology, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada, 4Department of Obstetrics, Gynecology and Newborn Care, The Ottawa Hospital, Ottawa, Ontario, Canada

INTRODUCTION: Most fetal DWI studies investigate singletons or rare twin-related diseases. This retrospective study investigates twin placental diffusion. METHODS: Two ADC-quantification methods were evaluated. Diffusion was compared within twins with double-disc placentas and between twins and normal singletons. RESULTS: ADC-quantification methods were significantly different. No significant diffusion difference was found within double-disc placental pairs or between twins and singletons with GA≤24 weeks. Comparison for GA>24 weeks could not be performed due to data paucity. DISCUSSION: Quantification discrepancy suggests non-uniform placental diffusion. Results suggest no twin-placental diffusion difference within twins or compared to singletons with GA≤24 weeks. Pathological correlation is required.

1543.   
A novel non-invasive MRI tool for quantification of placental oxygen transport in vivo
Reut Avni1, Joel Garbow2, and Michal Neeman1
1Biological Regulation, Weizmann Institute of Science, Rehovot, Israel, 2Biomedical MR laboratory, Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri, United States

Oxygen transport, one of several key functions performed by the placenta, depends primarily on placental oxygen pressure gradient and the oxygen affinity of fetal and maternal blood. We describe a novel, non-invasive MRI method for deriving MRI-based oxygen-hemoglobin dissociation curves. Pregnant ICR mice were analyzed using a gradual respiration challenge from hyperoxia to hypoxia. Apparent P50 (AP50) values, characteristic of oxygen affinity, derived from the curves, demonstrate a clear difference between adult and fetal tissues, as well as changes throughout gestation. This approach to probe and quantify oxygen transfer across the placenta may be useful for evaluation of fetal health.

1544.   Intravoxel Incoherent Motion Diffusion-weighted MR Imaging of the Placenta: Evaluation of Perfusion Changes in the Supine and Left Lateral Decubitus Positions
Skorn Ponrartana1, Sherin U Devaskar2, Jonathan M Chia3, Vidya Rajagopalan4, Hollie A Lai1, David Miller5, and Vicente Gilsanz1
1Radiology, Children's Hospital Los Angeles, Los Angeles, CA, United States, 2Pediatrics, University of California, Los Angeles, Los Angeles, CA, United States, 3Philips Healthcare, Cleveland, Ohio, United States, 4Radiology, Children's Hospital Los Angeles, CA, United States, 5Obstetrics and Gynecology, University of Southern California, CA, United States

This work evaluates the feasibility of intravoxel incoherent motion diffusion weighted imaging for evaluating changes in perfusion of placenta during known physiologic changes in arterial flow to the uterus in the supine and left lateral decubitus positions. Perfusion fraction maps of placenta in the two positions were compared. Mean perfusion fraction of the placenta was significantly higher in the left lateral decubitus position compared with the supine position. Intravoxel incoherent motion diffusion weighted imaging may be useful to study placental perfusion in clinical settings where there is concern of appropriate fetal growth.

1545.   An anthropomorphic MR phantom of the gravid abdomen including the uterus, placenta, fetus and fetal brain.
Pablo Garcia-Polo1, Borjan Gagoski2, Bastien Guerin3, Eric Gale3, Elfar Adalsteinsson4,5, P. Ellen Grant2, and Lawrence L. Wald3,5
1Martinos Center, MGH, M+Visión Advanced Fellowship, Charlestown, MA, United States, 2Fetal-Neonatal Neuroimaging & Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States, 3Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, United States, 4Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States, 5Harvard-MIT Health Sciences and Technology, Cambridge, Massachusetts, United States

Despite the importance of fetal brain development and the potential for fetal interventions, MRI is limited in its ability to assess fetal brain structure and physiology. The tremendous developments in accelerated parallel imaging, motion mitigated fast structural imaging as well as diffusion, perfusion and spectroscopy suggest that MRI is well placed to aid fetal healthcare, if these methods could be transferred and optimized for the specific issues of fetal imaging. A realistic anthropomorphic phantom of the gravid abdomen provides an important optimization platform to develop this technology for this sensitive patient population. We demonstrate a 5 compartment phantom with a “floating fetus” to aid coil and sequence development.

1546.   Comparison of US and MR measurement of fetal biometrics at 28-32 weeks with a real-time MR sequence
Nicholas Hilliard1, Rebecca Baker1, Andrew Patterson1, Martin Graves1, Christoph Lees2, Pat Set1, and David J Lomas1
1Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Cambridge, Cambridgeshire, United Kingdom, 2Department of Maternofetal Medicine, Imperial College Healthcare NHS Trust, London, United Kingdom

This study makes comparison between MRI and US measurements of standard fetal biometrics (abdominal circumference [AC], biparietal diameter [BPD], head circumference [HC] and femur length [FL]), in the fetus of 28-32 weeks gestational age. A real-time SSFSE sequence was developed to allow the MR operator to acquire images in the optimal plane for accurate measurement. Results show that BPD and HC measurements with MR were consistent. The length of time for acquisition was acceptable. Further development of the real-time SSFSE technique may be useful in comprehensive biometric assessment, and in situations where accurate measurements are important.

1547.   High resolution NMR parameter mapping of a CS23 chemically fixed human embryo at 9.4 T
Katsumi Kose1, Yosuke Otake1, Akiyoshi Nagata1, Tomoyuki Haishi2, and Shigehito Yamada3
1Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan, 2MRTechnology Inc., Tsukuba, Ibaraki, Japan, 3Kyoto University, Kyoto, Japan

T1, T2, proton density, and diffusion tensor of a Carnegie Stage 23 chemically fixed human embryo were measured to optimize the pulse sequences used for construction of the 3D anatomical database of the human embryo collection (Kyoto Collection). The results clarified that the correlation of the T1 and T2 is high, T1 and T2 of the liver were short comparing with other organs, and the volume of the liquid protons was about 30 % of the embryo specimen.

1548.   Comparison of uterine artery pulsatility and resistivity indices using magnetic resonance imaging and Doppler ultrasound
Rebecca Hawkes1, Andrew Patterson2, Andrew Priest2, Martin J Graves2, Nicholas Hilliard2, Patricia Set1, and David Lomas1
1Radiology, Addenbrooke's Hospital, Cambridge, Cambridgeshire, United Kingdom, 2Radiology, Addenbrooke's Hospital, Cambridge, Cambridge, United Kingdom

There is limited research regarding placental blood flow using MRI. The aim of this study was to evaluate whether uterine arteries could be identified on MRI, if a RI and PI could be measured and whether these were comparable with Doppler ultrasound. Using magnitude and phase MR images, likely uterine arteries were identified. Results demonstrated that uterine arteries can be identified on MR with a relatively small bias but with only moderate correlation for the PI/RI. MR phase contrast techniques allow for absolute flow quantification and the possibility of obtaining total uterine blood flow using this approach.

1549.   Study of the correlation between fetus ages and ossification center of atlanto-axial vertebrae using MRI
Hui Zhao1, Tianyi Qian2, Yong Wu1, Shuwei Liu3, Lianxiang Xiao1, and Xiangtao Lin1,3
1Shandong Medical Imaging Research Institute, Shandong University, Jinan, Shandong, China, 2MR Collaborations NE Asia, Siemens Healthcare, Beijing, China, 3China Research Center for Sectional and Imaging Anatomy, School of Medicine, Shandong University, Shandong, China

Currently, the question of when the ossification center of atlanto-axial vertebrae appears and could be detected by MR in human fetuses hasn¡¯t been fully answered yet. In order to address this question, we used the three-dimensional T2-weighted MR imaging technique to investigate the development process of ossification center in postmortem fetuses. By using a high-spatial-resolution T2-SPACE MR protocol, the changes of the ossification center of atlas and axis during fetus developing could be observed clearly. The emerging time of the ossification center of the axis dens could be a good sign for determining the fetal age.

1550.   Decidualized adenomyosis: MR imaging findings including diffusion-weighted imaging
Mayumi Takeuchi1, Kenji Matsuzaki1, and Masafumi Harada1
1Department of Radiology, University of Tokushima, Tokushima, Tokushima, Japan

We evaluated the MR imaging findings including DWI with ADC measurement of five decidualized adenomyosis (DA): 4 were during pregnancy, and 1 was under hormonal therapy. All DAs were demonstrated as heterogeneous signal intensity on T2WI containing prominent bright foci reflecting decidual reaction of endometrium within adenomyosis. On DWI the decidualized endometrial foci showed high signal intensity. The mean ADC of 4 DAs was 1.62 +/- 0.05, which was significantly higher than that of 14 malignant uterine myometrial tumors (0.85 +/- 0.15) (p=0.003). We conclude that ADC measurement may be helpful in distinguishing DA from malignant uterine tumors.

1551.   Multiparametric MRI Characterization of Funaki sub-types of Uterine Fibroids Considered for MRI-guided High-Intensity Focused Ultrasound (MR-HIFU) Therapy
Sajan Andrews1, Qing Yuan1, April Bailey1, Naira Muradyan2, Robert Staruch1,3, Rajiv Chopra1,4, and Ivan Pedrosa1,4
1Radiology, UT Southwestern Medical Center, Dallas, Texas, United States, 2iCAD Inc, Nashua, New Hampshire, United States, 3Philips Research, Briarcliff Manor, New York, United States, 4Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, Texas, United States

The purpose of this study was to correlate multiparametric magnetic resonance (MR) imaging data on symptomatic uterine fibroids being considered for MRgHIFU ablation with fibroid characterization based on the Funaki Classification scheme. We found significant differences in the pharmacokinetic and diffusion weighted imaging characteristics among the three traditionally reported fibroid types which may allow better selection of patients for MR-HIFU and other available therapeutic options.

1552.   Importance of Intravenous Contrast Administration to Improve the Diagnostic Accuracy of Preoperative MRI for Uterine Leiomyosarcoma
Gigin Lin1, Yu-Ting Huang1, Koon-Kwan Ng1, and Shu-Hang Ng1
1Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital and Institute for Radio, Chang Gung Memorial Hospital and Chang Gung University, Linkou, Taoyuan, Taiwan

This study is designed to assess the impact of gadolinium contrast administration on magnetic resonance (MR) in pre-operative diagnosis of uterine leiomyosarcoma (LMS). The central non-enhancing area (CNE) was identified as a MR characteristic for LMS, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.98, which was significantly greater than that of T1WI (AUC = 0.67, p < 0.01), T2WI (AUC = 0.65, p < 0.001) or DWI (AUC = 0.69, p < 0.001). CNE is an MR characteristic for LMS thus intravenous contrast medium administration is important for preoperative diagnosis of LMS.

1553.   Computed diffusion-weighted imaging for differentiating decidualized endometrioma from ovarian cancer
Mayumi Takeuchi1, Kenji Matsuzaki1, and Masafumi Harada1
1Department of Radiology, University of Tokushima, Tokushima, Tokushima, Japan

We evaluated DWI (b=800) with mean ADC values, and signal changes on computed DWI (cDWI) of 20 mural nodules (MNs) in 9 decidualized endometriomas (DEM) during pregnancy and 20 ovarian cancers (OC) retrospectively. MNs in DEM exhibited high to slight high intensity with significantly higher ADC (2.01 +/- 0.26), whereas all OC contained high intensity solid components with lower ADC (1.08 +/- 0.20) (p<0.001). The signal intensity of MNs in DEM decreased on cDWI with higher b values and all MNs showed low intensity on cDWI (b=1500) whereas all 20 OC still contained high intensity solid components on cDWI (b=1500).

1554.   Comprehensive Diagnostic Strategy for Cystic Masses in the Female Pelvis with Advanced MR Techniques
Mayumi Takeuchi1, Kenji Matsuzaki1, and Masafumi Harada1
1Department of Radiology, University of Tokushima, Tokushima, Tokushima, Japan

Various benign and malignant tumors and tumor-like lesions in the female pelvis may appear as cystic masses. We describe the optimized MR protocol for evaluating cystic masses and the added value of advanced MR techniques: Diffusion-weighted imaging; Fat/Water separation techniques; Susceptibility-weighted imaging; High-resolution MRI at 3T; 3D-Dynamic contrast enhanced MRI; MR Spectroscopy, in identifying the tumor origin, in distinguishing benign and malignant lesions, in estimating specific histological subtypes, and for the planning of adequate treatment.

1555.   MR Imaging Features of Ovarian Fibroma, Fibrothecoma and Thecoma
Sung Bin Park1, Jong Beum Lee2, and Hyun Jeong Park2
1Chung-Ang University Hospital, Seoul, Seoul, Korea, 2Chung-Ang University Hospital, Seoul, Korea

In summary, most ovarian fibrothecomas typically show homogenously low to intermediate signal intensity on T1-weighted images and low signal intensity on T2-weighted images, and appear predominantly solid. However, they often show atypical imaging features that mimic malignant lesions. We can determine the diagnostic clues and increase the diagnostic accuracy by detecting ipsilateral ovary on T2-weighted images with conventional MR imaging and use additional diffusion- or perfusion-weighted imaging.

1556.   AN INTERACTIVE COMPUTER-AIDED DIAGNOSIS SYSTEM FOR DETECTING METASTATIC LYMPH NODE IN FEMALE PELVIS BASED ON DIFFUSION WEIGHTED IMAGING
Tiing Yee Siow1, Yu-Chun Lin1, and Gigin Lin1
1Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, College of Medicine, Chang Gung University, Taoyuan, Taiwan

Manual depiction of lymph nodes on DWI is a time-consuming process, biased in inter- and intra-observer reproducibility exists in both detecting lymph nodes in DWI and measuring their size and apparent diffusion coefficient (ADC) values. We aim to develop an interactive system of computer-aided detection and diagnosis (CAD) for lymph node labeling on DWI. With optimal empirical parameters, the CAD showed a sensitivity of 85.0% with a positive predictive rate of 76.9%. The features render CAD a prospective tool for differentiating malignant and benign lymph node on DWI.

1557.   Faster and improved MRI of rectal tumors with a two sequence protocol based on high-resolution free-breathing post-contrast 3D SPGR imaging with comparison to standard care.
Andreas M. Loening1, Pejman Ghanouni1, Marcus T. Alley1, and Shreyas S. Vasanawala1
1Dept. of Radiology, Stanford University, Stanford, CA, United States

Conventional protocols for MRI staging of rectal tumors include multiple planes of T2-weighted imaging in addition to DWI and T1-weighted sequences, requiring 30-40 min to acquire. To decrease the time of these studies, we compared a conventional protocol to a 10-min fast protocol that utilized a single sequence of T2-weighted imaging in combination with a high-resolution free-breathing post-contrast 3D SPGR sequence. Two readers assessed imaging findings and assessed confidence scores from 20 patient cases. Despite greatly reduced acquisition time, the fast protocol demonstrated a significantly increased confidence in T and N staging, and a non-significant trend toward improved clinical staging.

1558.   Quantification of Sequence Parameter Effect on Geometric Distortions Caused by a Titanium Brachytherapy Applicator
Steven M Shea1, Abbie Diak2, Murat Surucu2, Matthew Harkenrider2, and Joseph M Yacoub1
1Radiology, Loyola University Chicago, Maywood, IL, United States, 2Radiation Oncology, Loyola University Chicago, Maywood, IL, United States

The use of MRI for cervical brachytherapy treatment planning is growing in popularity but geometric distortions from titanium applicators cause errors and uncertainty for treatment planning. Phantom experiments were performed to investigate sequence parameter variants from a standard 2D T2w turbo spin echo sequence. Quantitative measurements at the tip of the applicator showed that changes to readout bandwidth, even at the expense of increasing voxel size, can reduce artifacts while maintaining SNR and a reasonable imaging time.

1559.   Increased speed and image quality for single shot fast spin echo imaging in the pelvis via variable refocusing flip angles and full-Fourier acquisition
Andreas M. Loening1, Manojkumar Saranathan1, Daniel V. Litwiller2, Ann Shimakawa2, Lloyd Estkowski2, and Shreyas S. Vasanawala1
1Dept. of Radiology, Stanford University, Stanford, CA, United States, 2GE Healthcare Global MR Applications and Workflow, Rochester, MN/Menlo Park, CA, United States

Single shot fast spin echo (SSFSE) imaging is limited in acquisition speed by specific absorption rate (SAR), and compromised in image quality due to factors such as T2-decay over the echo train and half-Fourier k-space acquisition. We developed a variant utilizing variable refocusing flip angles (vrfSSFSE) that achieved a 2-fold reduction in TR at 3T due to reduced SAR, and due to T2-decay prolongation allowed full-Fourier k-space acquisition while retaining clinically relevant echo times. This pulse sequence was clinically tested for pelvic imaging in 25 patients, and demonstrated a doubling of imaging speed with improved image quality measures.

1560.   The Capabilities and Limitations of Clinical MRI Sequences for Detecting Kidney Stones. A Retrospective Study
El-Sayed H. Ibrahim1,2, Joseph Cernigliaro2, Mellena Bridges2, Robert Pooley2, and William Haley2
1University of Michigan, Ann Arbor, MI, United States, 2Mayo Clinic, Jacksonville, FL, United States

Computed tomography is established as the method of choice for kidney stone imaging, albeit its limitation of radiation exposure. However, MRI capability for detecting kidney stones has not been fully investigated, especially due to the stones’ appearance as non-specific signal void on MRI images. In this work, we conducted a retrospective study to document the performance of currently available MRI techniques for detecting kidney stones and to determine the characteristics of successfully-detected stones. The results show that MRI is capable of detecting about one-fifth of the stones, with stone size (8-mm threshold) and background-contrast as major factors for their visibility.

1561.   Assessment of renal blood flow and oxygenation in clear cell renal cell carcinomas using MRI
Han-Mei Zhang1, Xiao Lv2, Pan-Li Zuo3, Niels Oesingmann4, and Bin Song1
1Department of radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China, 2Department of Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, China, 3Siemens Healthcare, MR Collaborations NE Asia, Beijing, China, 4Siemens HC, New York State, United States

In order to reduce the risk of contrast material induced nephropathy by contrast-enhancement computed tomography and nephrogenic systemic fibrosis with renal insufficiency by contrast-enhancement magnetic resonance imaging have been of increasing concern, this study aimed to assess the performance of two noninvasive functional MRI methods, arterial spin-labeling (ASL) and blood oxygenation level dependent (BOLD) imaging, in characterizing the blood flow and oxygenation level of clear cell RCC.The results showed blood flow measured by ASL and oxygenation level by BOLD had significant differences between entire tumor and ipsilateral/contralateral renal cortex.

1562.   Multi-parametric MRI Evaluation of Chronic Kidney Disease – BOLD & Perfusion MRI
Jon Thacker1, Huan Tan2, Lu-Ping Li2,3, Wei Li2,3, Ying Zhou3, Orly Kohn2, Stuart Sprague2,3, and Pottumarthi Prasad2,3
1Northwestern University, Chicago, Illinois, United States, 2University of Chicago, Illinois, United States, 3NorthShore University HealthSystem, Illinois, United States

A joint BOLD and ASL MRI assessment of renal oxygenation and perfusion was performed in subjects with stage-3 CKD with diabetes. This group was found to have lower renal oxygenation levels (increased R2*) and decreased perfusion compared to a group of controls. A significant correlation was observed between perfusion and eGFR, and a negative correlation between R2* and eGFR. There was significant negative correlation between R2* and perfusion. These observations are consistent with chronic hypoxia theory.

1563.   Non-invasive Assessment of the whole kidney by MOLLI T1 Mapping in chronic kidney disease patients
Iris Friedli1, Lindsey Alexandra Crowe1, Lena Berchtold2, Solange Moll3, Karine Hadaya4, Pierre-Yves Martin4, Sophie De Seigneux4, and Jean-Paul Vallée1
1Division of Radiology, Faculty of Medicine, Geneva University Hospital, University of Geneva, Geneva, Switzerland, 2Division of Internal Medicine, Faculty of Medicine, Geneva University Hospital, University of Geneva, Geneva, Switzerland, 3Division of Pathology, Faculty of Medicine, Geneva University Hospital, University of Geneva, Geneva, Switzerland,4Division of Nephrology, Faculty of Medicine, Geneva University Hospital, University of Geneva, Geneva, Switzerland

There is an important need of non-invasive biomarkers to monitor, in situ, the chronic kidney disease (CKD) evolution. In this study, we investigated a free breathing Modified Look-Locker Inversion Recovery (MOLLI) motion corrected T1 mapping sequence in CKD patients to enable the difference between healthy volunteers and CKD patients. High image quality was obtained in all the patients. A highly significant difference in the mean T1 was revealed between the cortex but not the medulla of healthy volunteers and patients. This study justifies further clinical studies on the use of MOLLI T1 mapping in kidney patients.

1564.   Multiparametric MRI Evaluation of Chronic Kidney Disease – BOLD & Diffusion MRI
Lu-Ping Li1, Wei Li1, Jon Thacker1, Huan Tan1, Ying Zhou2, Orly Kohn3, Stuart Sprague4, and Pottumarthi V. Prasad1
1Center for Advanced Imaging, NorthShore University HealthSystem, Evanston, IL, United States, 2Center for Biomedical Research & Informatics, NorthShore University HealthSystem, Evanston, IL, United States, 3Department of Nephrology, University of Chicago, Chicago, IL, United States, 4Department of Nephrology, NorthShore University HealthSystem, Evanston, IL, United States

With the increasing prevalence of chronic kidney disease (CKD), the cost of care is a tremendous economic burden to healthcare system. With the lack of markers specific to CKD and to evaluate risk of progression, management is uniform and sub-optimal. The progression of CKD is thought to involve renal hypoxia and fibrosis. Blood oxygenation level dependent (BOLD) and diffusion MRI allow for non-invasive evaluation of renal hypoxia and fibrosis respectively. Here we show preliminary data with R2* and ADC in a group of CKD patients with diabetes compared to healthy controls. CKD had higher R2* and lower ADC values.

1565.   Comprehensive Assessment of Renal BOLD MRI using Multiple Moment Analysis: Application to Subjects with CKD
Jon Thacker1, Lu-Ping Li2,3, Wei Li2,3, Stuart Sprague2,3, and Pottumarthi Prasad2,3
1Northwestern University, Chicago, Illinois, United States, 2NorthShore University HealthSystem, Illinois, United States, 3University of Chicago, Illinois, United States

The purpose of this study was to evaluate a renal blood oxygenation level-dependent (BOLD) MRI analysis technique utilizing the entire renal parenchyma based on multiple moments of the R2* distribution. Multiple moment analysis is able to detect changes in subjects between baseline and following furosemide, as well as between control and CKD groups. This method may allow for a more robust analysis of R2* maps as compared to conventional ROI analysis in addition to minimizing observer subjectivity in analyzing renal BOLD data.

1566.   Large-FOV High Temporal Resolution Free-Breathing MR Urography using a Continuous Golden-Angle Radial Acquisition Scheme with Compressed Sensing Reconstruction: Feasibility and Comparison with Standard Cartesian Acquisition
Nainesh Parikh1, Justin Ream1, Hoi Cheung Zhang1, Tobias Block2, Hersh Chandarana1, and Andrew Rosenkrantz1
1Radiology, NYU School of Medicine, New York, NY, United States, 2Radiology, Center for Advanced Imaging Innovation and Research NYU School of Medicine, New York, NY, United States

We used a novel Golden-angle Radial Sparse Parallel (GRASP) sequence to perform free-breathing contrast-enhanced MR-urography with retrospective reconstruction of dynamic large-FOV images of the kidneys, ureters, and bladder at high spatial and high temporal (between 1-4 seconds) resolution. This technique provided visualization of the entire urothelial system, including of the bladder mucosa before gadolinium excretion, with reduced motion and ghosting artifact compared with a standard DCE sequence.

1567.   High non-linear diffusion fraction correlates with histological fibrosis in allograft kidneys
General Leung1,2, Nan Jiang3, Anthony A Sheen1, Serge Jothy4, Darren A Yuen2,5, and Anish Kirpalani1,2
1Medical Imaging, St. Michael's Hospital, Toronto, Ontario, Canada, 2Keenan Research Centre, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada, 3Faculty of Medicine, University of Toronto, Toronto, Canada, 4Department of Pathology, St. Michael's Hospital, Toronto, Ontario, Canada, 5Division of Nephrology, St Michael's Hospital, Toronto, Ontario, Canada

The signal acquired in a diffusion weighted sequence has been shown to be sensitive to both perfusion and diffusion components. We sought to find the degree to which flow and microcirculation are present in transplant kidneys by measuring the non-linear fraction of the diffusion curve in 8 patients. We compared these results to histopathology of the biopsy specimen. We demonstrate an increased non-linear diffusion fraction in patients with pathologically proven fibrosis. Further investigation of the pathological specimens are warranted to verify these findings.

1568.   IVIM-DWI and Non-contrast MRI of Allograft Kidneys in 48 hours after Transplantation
Yung Chieh Chang1, Yi-Ying Wu1,2, Jyh-Wen Chai1, and Clayton Chi-Chang Chen1
1Department of Radiology, Taichung Veterans General Hospital, Taichung City, Taiwan, 2Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung City, Taiwan

Delayed graft function is a form of acute renal failure that results in post-transplantation oliguria. Recently, the pathophysiology of renal ischemia and reperfusion injury has been recognized as the consequence to the development of delayed graft function. The goal of the present study is to perform IVIM MRI and non-contrast MRA in patients after renal transplantation to evaluate the micro-structural and macrocirculation status of graft kidneys. The experimental results may be considerably useful in early diagnosis of delayed graft function and also understanding the machanism of development of the disorder.

1569.   THE RELIABILITY OF MAGNETIC RESONANCE ELASTOGRAPHY (MRE) USING MULTISLICE 2D SPIN-ECHO ECHO-PLANAR IMAGING (SE-EPI) AND 3D INVERSION RECONSTRUCTION FOR ASSESSING RENAL STIFFNESS
Gavin Low1,2, Nicola Eve Owen3, Ilse Joubert1, Andrew J Patterson1, Kevin J Glaser4, Martin J Graves1, Graeme J.M. Alexander3, and David J Lomas1
1Radiology, Addenbrooke's Hospital, Cambridge, England, United Kingdom, 2University of Alberta, Edmonton, Alberta, Canada, 3Hepatology & Gastroenterology, Addenbrooke's Hospital, Cambridge, England, United Kingdom, 4Radiology, Mayo Clinic, Minnesota, United States

The purpose of this study was to evaluate the reliability of a novel renal MRE (magnetic resonance elastography) technique using spin-echo echo-planar imaging (SE-EPI) in healthy volunteers. The study population included 16 adult volunteers. Each participant underwent two renal MRE examinations, within a 30 minute interval between examinations. Two radiologists acted as independent readers. The test-retest repeatability and the inter-rater agreement of the renal MRE technique were assessed using Bland Altman, the within subject coefficient of variation, the coefficient of repeatability, and interclass correlation coefficient analysis. Our findings showed that SE-EPI renal MRE is a reliable imaging technique.

1570.   Visualization of Lupus Nephritis using SPIO
Ting Chen1,2, Yuki Mori1,2, Zhenyu Cheng1,2, Soyoung Lee1, Kai Wang1, Barry Ripley1, Tadamitsu Kishimoto1, Chizuko Inui-Yamamoto1,2, Fuminori Sugihara1, Noriko Kitagaki1, Yoshiyuki Tago3, Shinichi Yoshida3, Kohji Ohno4, and Yoshichika Yoshioka1,2
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, 3Biotechnology Development Laboratories, Kaneka Corporation, Takasago, Hyogo, Japan, 4Institute for Chemical Research, Kyoto University, Uji, Kyoto, Japan

a new contrast agent containing anti-Sm antibody was generated for visualizing the Lupus Nephritis in-vivo,the specific distribution pattern of it in the renal corpuscle may reflect the symptoms of kidney disease in SLE model mice, and it also showed us the possibility of diagnosing the SLE by this new particle.

1571.   MRI of Perirenal Pathology
James Glockner1 and Christine Lee1
1Radiology, Mayo Clinic, Rochester, MN, United States

MRI is an ideal technique for characterization of perirenal pathology. This exhibit discusses the anatomy of the perirenal space, and then illustrates the MRI appearance of a variety of common and uncommon pathologies.

1572.   Setup for Quick 2D Glomerular Imaging in a Clinical 3 T MRI System
Jorge Chacon-Caldera1, Raffi Kalayciyan1, and Lothar R Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, BW, Germany

The glomerular area can provide valuable information when evaluating kidney diseases such as glomerulosclerosis and chronic kidney disease. Despite its relevance, the study of glomeruli with MRI has remained unexploited due to the high technical requirements and long scanning times. In this study, we present a setup for glomerular imaging of ex vivo rat kidneys in a 3 T human clinical scanner whereby glomeruli are visible. The 2D glomerular imaging was performed in 7 minutes and 40 seconds, a factor ~13 reduction in comparison to the most recent study showing glomeruli at 3 T.

1573.   Metabolic Imaging of Renal Triglyceride Content: Validation by Porcine Kidney Biopsies
Paul de Heer1, Jacqueline T Jonker2, Evelien H van Rossenberg2, Marten A Engelse2, Trea CM Streefland3, Ton J Rabelink2, Andrew G Webb1, Patrick CN Rensen3,4, Hildo J Lamb5, and Aiko PJ de Vries2
1CJ Gorter Center for High Field MRI, Radiology, Leiden University Medical Center, Leiden, Netherlands, 2Nephrology, Leiden University Medical Center, Leiden, Netherlands,3Endocrinology, Leiden University Medical Center, Leiden, Netherlands, 4Einthoven Laboratory for Experimental Vascular Medicine, Leiden, Netherlands, 5Radiology, Leiden University Medical Center, Leiden, Netherlands

Obesity is an independent risk factor for development of nephropathy. However, human studies have been limited, because of the complication risk of repeated renal biopsies. Therefore, we assessed the reproducibility of the non-invasive 1H-MRS renal triglyceride (TG) measurement, compared to TG content in kidney biopsies, in an animal model. In total fourteen left-sided porcine kidneys were obtained. The average TG level in the renal cortex was 0.25±0.16% measured by 1H-MRS and 126±75 nmol/mg protein in biopsy. The Pearson correlation coefficient is 0.81 (p < 0.0001) showing good correlation The Bland-Altman analysis shows a bias close to zero confirming good correlation.

1574.   Functional Evaluation of Transplanted Kidneys with Reduced Field of View Diffusion-weighted Imaging at 3 T
Yuan Xie1, Yanjun Li1, Dandan Zheng2, Yong Zhang3, and Guangming Lu1
1Medical Imaging, Jingling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu, China, 2GE healthcare China, Beijing, China, 3GE healthcare China, Shanghai, China

DWI in human transplantation was regarded as a promising indicator of graft dysfunction. We performed DWI using rFOV ss-EPI with multi-b values in 46 renal allografts recipients. Our results showed cortical ADCT and FP differed significantly among eGFR levels. Cortical FP presented significant differences between each two subgroups and correlated positively and significantly with eGFR. In conclusion, the present investigation demonstrates that multi-b rFOV DWI holds potential for functional evaluation of renal allografts after transplantation.

1575.   Patients with high blood pressure should avoid aspirin: reduced renal perfusion in hypertensive EP4 knockout mice
Greg O Cron1,2, Jean-François Thibodeau1,2, Gerd Melkus1,2, Anthony Carter2, Ian G Cameron1,2, Nicola Schieda1,2, Wael Shabana1,2, and Chris Kennedy1,2
1Ottawa Hospital Research Institute, Ottawa, Ontario, Canada, 2University of Ottawa, Ottawa, Ontario, Canada

Hypertension vasoconstricts kidney vessels while NSAIDs (e.g. aspirin) suppress EP-receptor compensatory vasodilation, thus making hypertension and NSAIDS a potentially dangerous combination. Direct, in-vivo evidence of this phenomenon is lacking, however. We used DCE-MRI to compare renal perfusion in hypertensive mice with and without normal EP4 recepters, with the hypothesis that EP4 knockout mice would suffer reduced renal perfusion. This hypothesis was confirmed: In mice with AngII-induced hypertension, suppression of the EP4 receptor led to a catastrophic reduction in renal perfusion. This supports the idea that NSAIDs are bad for hypertensive patients and hints that EP4-selective activation (pharmacologically) may be beneficial.

1576.   MEASUREMENT OF RENAL CORTICAL THICKNESS USING NON-CONTRAST-ENHANCED STEADY-STATE FREE PRECESSION (SSFP) MRI WITH SPATIALLY SELECTIVE IR PULSE: ASSOCIATION WITH RENAL FUNCTION
Yasufumi Noda1, Katsuyoshi Ito1, Tsutomu Tamada1, Akira Yamamoto1, Kazuya Yasokawa1, and Atsushi Higaki1
1Department of Radiology, Kawasaki Medical School, Kurashiki, Okayama, Japan

The purpose of this study is to assess whether noncontrast-enhanced SSFP MRI with a spatially selective IR pulse can improve the visibility of renal corticomedullary differentiation to measure renal cortical thickness in patients showing renal dysfunction, and to investigate the correlation between renal cortical thickness and eGFR. Mean corticomedullary contrast ratio was higher in SSFP images with optimal TI than in IP images. Additionally, positive correlation was observed between minimal renal cortical thickness and eGFR. This fact suggested that non-contrast-enhanced SSFP MRI using this technique has a potential to evaluate the renal dysfunction with higher sensitivity than conventional imaging.

1577.   Assessment of renal allograft perfusion and diffusion using renal ASL and IVIM
Tao Ren1, Hua Li Chen1, Li Pan Zuo2, Thorsten Feiweier3, Niels Oesingmann4, and Wen Shen1
1Department of Radiology, Tianjin First Center Hospital, Tianjin, Tianjin, China, 2Siemens Healthcare, MR Collaborations NE Asia, Beijing, China, 3Siemens Healthcare, Erlangen, Germany, 4Siemens HC, New York, United States

To assess the cortex perfusion and diffusion parameters derived from ASL and IVIM in allografts after kidney transplantation. 32 allograft renal divided in two groups according to the eGFR,and 16 healthy volunteers were involved, scanned using ASL¡¢IVIM sequence. ASL derived RBF and IVIM derived Dfast, Dslow and PF were compared between three groups by ANOVA with Bonferroni test. Dslow,PF and RBF has statistic difference between three groups (P <0.05).However, the differences between groups were higher in RBF than in Dslow and PF.Compared with IVIM, cortex perfusion information provided by ASL was more sensitive to evaluate the renal function.

1578.   Quantification and reproducibility of single kidney function using DCE-MRI in healthy subjects
Eli Eikefjord1,2, Erling Andersen3, Jan Ankar Monssen1, Erlend Hodneland4, Erik Hanson5, Arvid Lundervold1,4, and Jarle Rørvik1,2
1Radiology, Haukeland University Hospital, Bergen, Hordaland, Norway, 2Clinical Medicine, University of Bergen, Bergen, Hordaland, Norway, 3Clinical Engineering, Haukeland University Hospital, Bergen, Hordaland, Norway, 4Biomedicine, University of Bergen, Hordaland, Norway, 5Mathematics, University of Bergen, Hordaland, Norway

Documentation on reproducibilities in estimation of renal functional parameters using DCE-MRI is limited. Twenty healthy subjects being in a controlled physiological state were examined twice with identical 3D SPGR DCE-MRI acquisition technique, aiming at exploring intra-subject reproducibility and variability in perfusion and filtration estimates. Within-subject variation was 14-24% and estimates were reproduced with good to excellent agreement between MR1 and MR2. Mean difference in total GFR and renal blood flow between MR1 and MR2 was 3.5 ml/min and 43.7 ml/100ml/min, respectively. Variance and agreement correspond to expected levels accounting for normal physiological variation and instances of quality impaired exams.

1579.   Application and analysis of multi-echo sequences for Renal MRI using EPG
Sneha Prakash Potdar1, Manoj G Bhosale1,2, Shivaprasad Ashok Chikop1, Shaikh Imam1, Antharikashanagar Bellappa Sachin Anchan1, and Sairam Geethanath1
1Medical Imaging Research Centre, Dayananda Sagar Institutions, Bangalore, Karnataka, India, 2BioMedical Instrumentation, Government College of Engineering Pune (COEP), Pune, Maharashtra, India

This study has been performed to show relative gain in SNR and reduced blurring caused due to T2 decay in multi-echo sequences in renal MR. The magnetization of spins was based on PSS design so as to increase the amplitude of later echoes to maximum. To validate the hypothesis In-Silico and In-vivo simulation have been performed in kspace on acquired renal MR images. The results showed the significant increase in SNR in the region of interest (ROI) relevant to renal anatomy proving the effectiveness of this approach for clinical diagnosis

1580.   Low field renal contrast optimization with a portable 0.5T system
Florian Lietzmann1, Mathias Düsberg1, and Lothar R. Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Baden-Württemberg, Germany

Nowadays 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 such images. This work presents initial results of contrast optimization of a rodent kidney with a portable system at 0.5 T.

1581.   A simple method to optimize partial Fourier acquisition schemes for glomerular imaging
Jorge Chacon-Caldera1 and Lothar R Schad1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, BW, Germany

A partial Fourier acquisition strategy was purpose-built. The method was applied to the imaging of glomeruli in the kidney and compared to two commonly used PF acquisition strategies. The imaging of glomeruli is a recently introduced research area in MRI that could potentially help the early diagnose of kidney diseases. Knowledge from one full k-space acquired image was obtained and used it to find the maximum frequency harmonic required to resolve a selected spatial frequency. From the maximum frequency harmonic, a minimum range of harmonic frequencies required in k-space was selected.

1582.   Robust and Noninvasive Measurement of Renal Perfusion using Multi-Phase Pseudo-Continuous Arterial Spin Labeling
William Jeffrey Triffo1 and Youngkyoo Jung2
1Department of Radiology, Wake Forest School of Medicine, Winston Salem, NC, United States, 2Departments of Radiology and Biomedical Engineering, Wake Forest School of Medicine, Winston Salem, NC, United States

The accuracy of pseudo-continuous ASL (PCASL) methods is sensitive to phase errors related to off-resonance effects at the tagging plane. Respiratory motion is also a well-known problem in body imaging. We present the application of multi-phase PCASL (MP-PCASL) to study renal perfusion, along with a masked object registration algorithm for semi-automatic alignment after breath-hold acquisition. Example data illustrating off-resonance induced errors in the PCASL estimation of renal blood flow and the associated phase errors are provided. MP-PCASL provides a robust alternative that is insensitive to such errors.

1583.   Accurate quantification of blood perfusion in the kidney using pseudo-continuous arterial spin labelling: an optimisation and reproducibility study
Susie Clarke1, James F Meaney1, and Andrew J Fagan1
1National Centre for Advanced Medical Imaging (CAMI), St. James's Hospital / Trinity College Dublin, Dublin 8, Ireland

The measurement of blood perfusion in the kidney using a non-contrast approach was investigated. A protocol was optimised using pseudo-continuous arterial spin labelling coupled with a TSE readout, and the reproducibility of the resulting measurements assessed in a healthy cohort. A spatial resolution of 2.5x2.5x6mm3 was obtained with an SNR of 56±3, allowing for separation of cortex and medulla regions in the calculated perfusion maps. Mean perfusion values of 293±44 / 139±20 ml/100g/min were measured in the cortex/medulla respectively, with good intra- and inter-session reproducibility. Good breath-hold tolerance reported by the volunteers suggests that clinical implementation is feasible.

1584.   Urinary 1H NMR-based Metabolomics can Distinguish Sub-fertility Buffalo Bulls
Virendra Kumar1, Pawan Kumar1, Khushpreet Singh2, N R Jagannaathan1, and Ajeet Kumar2
1Department of NMR, All India Institute of Medical Sciences, New Delhi, Delhi, India, 2Department of Veterinary Gynaecology and Obstetrics, College of Veterinary Science, GADVASU, Ludhiana, Punjab, India

Sub-fertility in bulls is a major problem and results into huge economic loss. Identification of potential metabolic biomarkers to determine the fertility at earlier developmental stage accurately is important. In present study we used 1H NMR-based metabolomics to investigate the metabolic profile differences in urine samples to differentiate between buffalo bulls of good fertility and poor fertility. The results of the PLS-DA revealed that sub-fertile bulls be differentiated from fertile bulls based on altered urinary metabolic profiles. Further analysis will be carried out to identify potential metabolic biomarkers which could be used for fertility assessment.

1585.   Imaging Features of Leiomyoma in the Genitourinary Tract: Beyond the Uterus
Sung Bin Park1
1Chung-Ang University Hospital, Seoul, Seoul, Korea

Unusual leiomyoma may mimic malignant tumor. It is important to know unusual manifestations, growth patterns of uterine leiomyoma and locations in the genitourinary tract.

1586.   Tracking of bladder motion and gut peristalsis using MRI.
Veerle Kersemans1, Philip D Allen1, John S Beech1, Stuart Gilchrist1, Paul Kinchesh1, and Sean C Smart1
1Department of Oncology, University of Oxford, Oxford, OXON, United Kingdom

Bladder filling and gut peristalsis are significant confounds to high quality abdominal imaging. As a result, imaging in this region needs to be performed rapidly in order to reduce motion-induced resolution loss. Scans that are sufficiently long in duration to allow these motions to corrupt the images cannot have the desired resolution and may provide no more information than shorter scans. Integration of MR data into the radiotherapy planning and treatment will have to be performed within a short time period. The reported approach allows fast, high-resolution imaging which will result in more accurate examinations of the lower abdomen.

Tuesday 2 June 2015
Exhibition Hall 10:00 - 12:00

1587.   Radioembolization dosimetry using gadoxetate disodium for segmentation of the healthy liver parenchyma
Hanke J Schalkx1, Jip P Prince1, Gerrit H van de Maat2, Peter R Seevinck3, Clemens Bos3, Wouter B Veldhuis1, Maarten S van Leeuwen1, Maurice AAJ van den Bosch1, Marnix GEH Lam1, and Marijn van Stralen3
1Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Quirem Medical BV, Diepenveen, Netherlands, 3Image Sciences Institute, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands

In intra-arterial radioembolization for the treatment of non-resectable liver cancer, the amount of injected activity is limited by its effect on the healthy parenchyma. Therefore, it is essential that the healthy parenchymal volume is measured accurately. In a holmium-treated patient population, the role of gadoxetate-enhanced MRI was investigated. Automatic segmentation of the liver parenchyma without hypointense tumors and vessels was feasible. Gadoxetate-based automatic segmentation of the nontumorous hepatic parenchyma could benefit radioembolization dosimetry and dosimetry-based treatment planning.

1588.   Variable Refocusing Flip Angle Single-Shot Fast Spin Echo of the Bowel, Initial Experience
Daniel V Litwiller1, James F Glockner2, and Ersin Bayram3
1Global MR Applications and Workflow, GE Healthcare, Rochester, MN, United States, 2Department of Radiology, Mayo Clinic, Rochester, MN, United States, 3Global MR Applications and Workflow, GE Healthcare, Houston, TX, United States

Single-Shot Fast Spin Echo (SSFSE) imaging of the bowel is limited in several ways, including T2-driven image blurring, which limits effective resolution, and high SAR (especially at 3.0T), which limits repetition time and therefore acquisition speed. Here, we present initial bowel imaging results from variable refocusing flip angle SSFSE (vrfSSFSE), which demonstrates markedly improved image sharpness, resulting in improved appearance of the bowel and mesentery, features that are typically lacking in bowel imaging with conventional SSFSE using static refocusing flip angles. In addition, increased imaging speed with vrfSSFSE can be used to shorten breath-held acquisitions or to increase slice coverage.

1589.   Whole-Body Continuously Moving Table Fat Water Imaging with Dynamic Capital Greek DeltaB0 Shimming
Saikat Sengupta1,2, David S Smith1,2, and E. Brian Welch1,2
1Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, United States, 2Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, United States

Multiecho MRI with a Continuously Moving Table (CMT) enables rapid mapping and quantification of whole-body fat/water content. A limitation of CMT MRI is that the center-frequency (f0) and B0 shims are optimized at one location of the body resulting in non-optimal fields in other anatomical sections. In this work, we present a solution to this problem by dynamically shimming different locations of the body during a multiecho radial CMT fat/water scan with shim and f0 settings optimal for each individual anatomical location. We demonstrate slice optimized shimming and fat/water separation in 5 different locations of the body.

1590.   Application of mathematical modelling to a DCE-MRI phantom: predicting the shape of contrast agent uptake curves.
Laura Smith1, Marco Borri1, Araminta EW Ledger1, Craig Cummings1, Maria A Schmidt1, and Martin O Leach1
1CR-UK Cancer Imaging Centre, Sutton, Surrey, United Kingdom

In previous work we reported a novel DCE-MRI test object of simple and affordable design, which can create reproducible uptake curves. In this work we demonstrate that it is possible to derive a series of simple, smooth transfer functions which describe the evolution of the contrast agent uptake curve along the dynamic test object. Furthermore, the derived transfer functions were validated: they were able to predict the experimental curves at different locations within the test object in a series of experiments with different input functions.

1591.   Assessment of system linearity and response to input parameters in a Dynamic Contrast-Enhanced (DCE) MRI phantom
Laura Smith1, Araminta EW Ledger1, Marco Borri1, Craig Cummings1, Maria A Schmidt1, and Martin O Leach1
1CR-UK Cancer Imaging Centre, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom

There is a need to prospectively assess the effect of parameter alterations on contrast agent (CA) uptake curves in DCE-MRI protocols. This abstract investigates the behaviour of a novel and inexpensive phantom, designed to create reproducible CA uptake curves for quality assurance (QA) of DCE-MRI sequences. Here we establish the linear behaviour of the phantom and demonstrate that alteration of input parameters produces predictable variation in CA uptake curves. A tuneable reference CA uptake curve will be a valuable QA tool and can be used to investigate the effect of parameter variation on CA uptake curves in DCE-MRI protocols.

1592.   Homogeneous free whole-body Lava-flex using an adaptive center frequency technique at 3T
Lizhi Xie1, Bing Wu1, Nan Hong2, Yingkui Zhang1, and Zhenyu Zhou1
1GE Healthcare China, Beijing, Beijing, China, 2Peking University People's Hospital, Beijing, China

Whole body lava-flex provides valuable information with or without contrast enhancement and is supplemental to whole-body diffusion-weighted imaging due to its high spatial resolution. We propose a new adaptive center frequency method for WBLF protocols to achieve homogenous images at 3T scanner that requires no additional calibration and minimal operator interaction.

1593.   Brown Adipose Tissue Thermometry in the Paraventricular Specific Knock-out Mouse Model at 15.2T
Myriam Diaz Martinez1, Henry H Ong1, Masoud Ghamari-Langroudi2, Aliya Gifford1,3, Roger Cone2, and E Brian Welch1
1Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, United States, 2Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, United States, 3Physical and Chemical Biology Program, Vanderbilt University Medical Center, Nashville, TN, United States

Direct and non-invasive measurements of brown adipose tissues’ (BAT) temperature is crucial for understanding its role in thermoregulation in the mouse. We have implemented a novel fat-water MRI (FWMRI) method with explicit modeling of temperature which is dependent on the water frequency offset to estimate the interscapular BAT temperature at thermoneutral environment in the Paraventricular (PVN) specific knock-out mouse model, at ultra high field (15.2T) using the Bruker CryoProbe surface coil with 2D FLASH sequence, with multi-interleaved echo count. Our results demonstrate the potential of MRI to detect subtle changes in temperature of brown adipose tissue in mice.

1594.   Nonalcoholic Fatty liver Disease: Correlation of the liver parenchyma fatty acid with intravoxel incoherent motion MR imaging-An Experimental study in rat model
Seung-Man Yu1 and Hyeon-Man Baek2
1Dep. of Radilological Science, Gimchoen University, Gimcheon, Gyeongsangbuk-do, Korea, 2Center for MR Research, Korea basic Science Institue, Ochang/Chungbuk, Korea

This study focus on non-alcoholic fatty liver disease.

1595.   MRI/S Assessment of Cardiac Morphology/Function and Skeletal Muscle Energetics in Mitochondrial DNA Mutated Mice
Hasan Alsaid1, Mary V Rambo1, Tinamarie Skedzielewski1, Ruth R Osborn2, Alicia M Davis M Davis2, William Rumsey2, and Beat M Jucker1
1Preclinical & Translational Imaging, LAS, PTS, GlaxoSmithKline, King of Prussia, PA, United States, 2Stress Repair DPU, Respiratory TAU, GlaxoSmithKline, King of Prussia, PA, United States

In this study, we assessed cardiac morphology/function and skeletal muscle energetics in mitochondrial DNA mutated PolG mice (Polymerase gamma-deficient) that had been either exposed to cigarette smoke, forced air, or room air for 5 months. Skeletal muscle energetic compromise was observed in the PolG mice. Initial stages of heart failure appears to be present in the PolG mice compared to the wild type mice as reflected by the lef ventricular chamber dilation and the increase in the normalized lef ventricular mass to body weight. Cardiac function is still preserved in all groups. No differences in gender or smoke exposure were found between groups.

1596.   Safeguarding the Family Jewels: Using MRI to Monitor for Testicular Toxicity
Denise Welsh-McCracken1, Yvonne Van Gessel1, Dierdre Scully2, Jacob Hesterman2, and Paul J McCracken1
1Eisai, Andover, MA, United States, 2InviCRO, Boston, MA, United States

Drug induced testicular toxicity creates a potential obstacle to moving promising new therapies into clinical trials. We investigate the utility MRI for detecting and monitoring testicular toxicity in a rat pilot study. Mild toxicity was induced in mature male SD rats using 1,3 Dinitrobenzene (35mpk po). Rats were imaged on days 0, 3,5, and 15. T2-weighted image data were bias-field corrected and manually segmented to isolate the testes signal. 2D fast Fourier transform (FFT) was used to map data to the spatial frequency domain. Fourier analysis revealed decreased group average AUCs at days 3 and 5, reaching significance at day15.

1597.   High Field Magnetic Resonance Angiogram of the Mouse Eye
Gangchea Lee1, Minjung Kim2, and Thomas Neuberger1,3
1Biomedical Engineering, Pennsylvania State University, University Park, PA, United States, 2Biology, Pennsylvania State University, University Park, PA, United States, 3Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, United States

Retinal and choroidal vessels deliver the nutrition and oxygen to maintain homeostasis for proper vision. The damage on retina can cause a severe outcome of loss of sight. In this study the feasibility generating a three dimensional angiogram of the mouse eye using MRI was explored. A magnetic field of 14 tesla and a dedicated home built radiofrequency surface coil were used to create a 30 um isotropic resolution angiogram of the mouse eye. The results of this non-invasive study could be used to investigate many ocular diseases, such as diabetic retinopathy.

1598.   
B0 inhomogeneity correction of T2* from fat-water MRI: application to a diet-induced obesity mouse model at 15.2T
Henry H. Ong1,2, Corey D. Webb3, Marnie L. Gruen3, Alyssa H. Hasty3, John C. Gore1,2, and E. Brian Welch1,2
1Vanderbilt University Institute of Imaging Science, 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

Previously, we investigated the potential of T2* estimated from quantitative fat-water MRI (FWMRI) as a marker of adipose tissue inflammatory changes due to adipocyte iron overload in an established diet-induced obesity mouse model at 15.2T. Preliminary results indicated presence of large background B0 variations (50-250 Hz/mm) that could adversely affect T2* mapping. Here, we implement a recently proposed B0 variation correction of FWMRI data. Using a subset of our previous data, we show feasibility of this correction method for in vivo mouse data at 15.2T. The correction primarily affects T2* and not fat-signal-fraction or Capital Greek DeltaB0 in agreement with previous reports.

1599.   Improved IVIM model fitting with non-rigid motion correction
Oscar Gustafsson1,2, Mikael Montelius1, and Maria Ljungberg1,2
1Department of Radiation Physics, University of Gothenburg, Göteborg, Sweden, 2Department of Medical Physics and Biomedical Engineering, Sahlgrenska University Hospital, Göteborg, Sweden

The number of b-values needed for robust IVIM model fitting, when imaging the liver, can usually not be acquired during a single breath-hold. This introduces the possibility of inter-scan motion, which most likely will degrade the quality of the subsequent IVIM model fit. In this study we show that non-rigid motion correction is essential when image acquisition for IVIM in the liver is split into multiple breath-holds.

1600.   Evaluation of different mathematical models for diffusion weighted imaging of prostate cancer xenografts in mice
Harri Merisaari1,2, Hanne Hakkarainen3, Heidi Liljenbäck1,4, Helena Ahtinen1,4, Heikki Minn5, Matti Poutanen4,6, Anne Roivainen1,4, Timo Tiimatainen3, and Ivan Jambor7
1Turku PET Centre, University of Turku, Turku, Finland, 2Department of Information Technology, University of Turku, Turku, Finland, 3Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, Kuopio, Finland, 4Turku Center for Disease Modeling, University of Turku, Turku, Finland, 5Department of Oncology and Radiotherapy, Turku University Hospital, Turku, Finland, 6Department of Physiology, University of Turku, Turku, Finland, 7Department of Diagnostic Radiology, University of Turku, Turku, Finland

We have evaluated fitting quality and repeatability of four mathematical models for diffusion weighted imaging (DWI) during tumor progression (PC-3) in mouse xenograft model of prostate cancer. Tumor growth was followed by weekly DWI examinations for 4 weeks using an animal 7T MR scanner. Significant changes were observed in DWI data during the tumor growth, indicated by ADCm, ADCs, and ADCk. Stretched exponential and kurtosis models showed better fit to DWI data than the mono-exponential model and presented with good repeatability.

1601.   Improved Abdominal Diffusion Weighted Imaging at 3T using Optimized Shinnar-Le Roux Adiabatic Radiofrequency Pulses
Hadrien Dyvorne1 and Priti Balchandani1
1Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States

At 3T, radiofrequency B1 field inhomogeneity affects data quality and signal to noise ratio of abdominal diffusion weighted imaging (DWI). The purpose of this work is to develop new approaches for 3T abdominal DWI, that rely on the use of adiabatic pulses in a single- or twice-refocused acquisition. We show that adiabatic RF pulses lead to increased signal in regions suffering from B1 inhomogeneity, which in turn results in improved quality for apparent diffusion coefficient maps measured in a healthy volunteer at 3T.

1602.   
Clinical feasibility of time-dependent diffusion MRI for improved prostate cancer grading
Gregory Lemberskiy1,2, Dmitry S Novikov1, Henry Rusinek1, Els Fieremans1, and Andrew Rosenkrantz1
1Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States, 2Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine, New York, NY, United States

Synopsis: Time-dependent diffusion can be used to distinguish populations of low grade/high grade and benign tissue in prostate tissue. We found that peripheral zone experiences transient time-dependence, while tumors have a constant dependence in the same range. Adding time-dependent ADC acquisitions for such analysis is clinically feasible as it costs ~7 minutes without the use of state of the art acceleration techniques.

1603.   
A Spatially Constrained Probability Distribution Model of Incoherent Motion (SPIM) in Quantitative Diffusion Weighted MRI
Sila Kurugol1, Moti Freiman1, Onur Afacan1, and Simon K Warfield1
1Radiology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States

Quantitative diffusion-weighted MRI (DW-MRI) is well-established role in characterization of abnormalities including liver fibrosis and tumors. Diffusion of molecules leads to attenuation in the diffusion signal measured at multiple b-values. This attenuation has slow and fast components associated with diffusion and microcirculation, represented by bi-exponential model of the intravoxel incoherent motion (IVIM). Fast diffusion can occur over a large range of length and time scales. In this work, we introduce a spatially-constrained two-component probability mixture model of diffusion (SPIM) for the precise characterization of the multi-scale heterogeneous diffusion. We compare the SPIM model with the IVIM in 68 abdominal DW-MRIs.

1604.   
Proposal and Evaluation of a Parameter free segmented Multistep Algorithm to assess Diffusion Data with a combined IVIM-DKI Model
Moritz C Wurnig1, David Kenkel1, Lukas Filli1, and Andreas Boss1
1Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Zurich, Switzerland

A recently proposed parameter-free segmented-multistep-algorithm was expanded to derive the model-parameters in a combined IVIM-DKI-diffusion-model. Its goodness-of-fit was compared with the simpler IVIM-diffusion-model. Diffusion-data-sets (6 volunteers,16 b-values) were acquired using a 3T-MR-scanner. A region-of-interest-analysis (abdominal organs, skeletal muscle) was performed and parametrical maps computed. Mean D-values significantly increased in all assessed organs when using the IVIM-DKI-model (all p< 0.02) accompanied by a significantly better fitting-curve in liver, pancreas and the renal medulla (all p< 0.02). We conclude that IVIM-DKI describes diffusion more accurately and might be used for more precise tissue-characterization without organ-specific adaptions using the proposed algorithm.

1605.   Readout-Segmented EPI with Simultaneous, Multi-Slice Acceleration for the Rapid Acquisition of High-Resolution, Diffusion-Weighted Images of the Breast
Wei Liu1, Himanshu Bhat2, Elisabeth Weiland3, Dingxin Wang4, Thomas Beck3, Stephen F. Cauley5, and David A. Porter6
1Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, Guangdong, China, 2Siemens Medical Solutions USA, Inc., Charlestown, MA, United States, 3MR Application Development, Siemens Healthcare, Erlangen, Germany, 4Siemens Medical Solutions USA, Inc., Minneapolis, MN, United States, 5A.A. Martinos Center for Biomedical Imaging, Dept. of Radiology, MGH, Charlestown, MA, United States, 6Fraunhofer MEVIS, Institute for Medical Image Computing, Bremen, Germany

Clinical studies evaluating breast DWI have shown that rs-EPI provides an improved diagnostic performance compared to ss-EPI. However, one disadvantage of rs-EPI is a longer scan time, which increases with the number of readout segments. In this study, we demonstrate the application of simultaneous multi-slice accelerated rs-EPI using blipped-CAIPIRINHA to DWI of the breast, providing a substantial reduction in scan time or increase in slice coverage or resolution compared to standard rs-EPI, whilst maintaining image quality.

1606.   Realtime B0 Inhomogeneity Correction In Multi-station Diffusion Imaging
Maggie M Fung1, Wu Gaohong2, Lloyd Estkowski3, Dan Xu2, Scott Hinks2, and Ersin Bayram4
1Global MR Applications and Workflow, GE Healthcare, New York City, NY, United States, 2Global MR Applications and Workflow, GE Healthcare, Waukesha, WI, United States,3Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States, 4Global MR Applications and Workflow, GE Healthcare, Houston, TX, United States

Diffusion weighted imaging (DWI) using single shot EPI routinely suffers from distortion due to B0 inhomogeneity. The degree of distortion is proportional to the B0 inhomogeneity, which increases non-linearly as the distance from iso-center increases. This causes mis-registration between stations in whole body multi-station DWI and also limits the maximum SI coverage per station that can be achieved. In this study, we proposed a real-time method to detect & correct the B0 offset per slice and demonstrated the reduction in distortion. This real-time method does not require additional reference scan or B0 map collections.

1607.   A comparison of intravoxel incoherent motion (IVIM) fitting models in the liver
Alexander D. Cohen1, Mark D. Hohenwalter1, and Kathleen M. Schmainda1,2
1Radiology, Medical College of Wisconsin, Milwaukee, WI, United States, 2Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States

The best model for fitting the IVIM signal is still unknown. Previous studies have used several different models and achieved different results. This study compared three models: full, segmented, and Bayesian, in terms of parameter value and repeatability in normal liver parenchyma. For pseudodiffusion, all three models significantly differed with each other. The Bayesian model resulted in the highest pseudodiffusion, followed by the full model and then the segmented model. Repeatability was comparable for the full and segmented models. The Bayesian model had worse repeatability for fractional perfusion and pseudodiffusion, despite less noisy parametric maps.

1608.   Spatially-Constrained Incoherent Motion (SCIM) Model Improves the Robustness of Fast and Slow Diffusion Parameter Estimation from DW-MRI Data in Various Multiple b-Value Acquisition Protocols
Vahid Taimouri1, Moti Freiman1, and Simon K Warfield1
1Radiology, Boston Children's Hospital, Boston, MA, United States

The Spatially-Constrained Incoherent Motion (SCIM) model aims to improve the quality of the fast and slow diffusion parameter estimates by utilizing a spatial homogeneity of the signal decay parameters as an informative prior to guide the estimation, and effectively estimates parametric maps representing the signal decay model using the Fusion Bootstrap Moves (FBM) solver. Here, we aim at evaluation of the SCIM model on improving the robustness of fast and slow diffusion parameter estimates in the ileum against acquisition protocols that utilize different choices of b-values.

1609.   Diffusion-weighted Imaging using a Statistical Model as a Functional MRI of the Kidney: Preliminary Experience
Kentaro Yamada1, Hiroshi Shinmoto1, Seigo Ito2, Hiroo Kumagai2, Tatsumi Kaji1, and Koichi Oshio3
1Radiology, National Defense Medical College, Tokorozawa, Saitama, Japan, 2Nephrology and Endocrinology, National Defense Medical College, Saitama, Japan, 3Diagnostic Radiology, Keio University School of Medicine, Tokyo, Japan

The purpose of this study was to evaluate the appropriateness of diffusion-weighted imaging (DWI) using a statistical model based on a truncated-Gaussian distribution for diffusion signal decays of the kidney and their correlation with renal function. Nineteen patients with renal diseases and 13 healthy volunteers were included. DWI was performed using five b-values (0, 500, 1000, 1500, and 2000). The statistical model yielded a statistically better fit compared to the mono-exponential model (P<0.01). Fraction of ADC<1.0 (%) showed good correlation with renal function. This model might aid in interpreting diffusion MR signals related to histological changes in the kidney.

1610.   Read-fly : Homogeneous and distortion free whole body diffusion weighted imaging at 1.5T and 3 T
Lizhi Xie1, Bing Wu1, Ning Wu2, Xiaocheng Wei1, and Zhenyu Zhou1
1GE Healthcare China, Beijing, Beijing, China, 2Chinese Academy of Medical Sciences Cancer Hospital, Beijing, China

Propose a new whole-body diffusion-weighted MR imaging protocol for achieving distortion free and homogenous whole body DW images at both 3.0T and 1.5T scanners that require no additional calibration and minimal operator interaction.

1611.   Lesion detection and workflow optimization in whole body diffusion MR imaging using trimodality PET/CT+MR in the oncology setting.
James L. Patrick1, Perry J. Pickhardt1, Hyungseok Jang1, Scott B. Perlman1, and Alan B. McMillan1
1Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States

The purpose of this study is to evaluate a rapid, whole-body MR protocol to determine the value PET/CT+MR “tri-modality” imaging provides in addition to conventional PET/CT with respect to small lesion detection. All FDG-avid visceral organ lesions and lymphadenopathy seen on PET/CT demonstrated restricted diffusion on DWI. Rapid trimodality whole body DWI MRI shows a good correlation with FDG avid lesions in the oncological setting, and DWI may help improve clinical confidence in small PET/CT equivocal lesions. Whole body DWI can be performed within the time constraints of a normal diagnostic PET/CT thereby adding additional information without affecting workflow.

1612.   Evaluation of urinary bladder cancer on synthetic FOCUS diffusion weighted imaging
Motoyuki Katayama1, Takayuki Masui1, Kimihiko Sato1, Kei Tsukamoto1, Kenichi Mizuki1, Maho Hayashi1, Tetsuya Wakayama2, and Yuji Iwadate2
1Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan, 2GE Healthcare Japan, HIno, Tokyo, Japan

We evaluated 39 patients with 52 urinary bladder cancer on synthetic DWI calculated from FOCUS DWI. Compared with conventional FOV DWI, FOCUS DWI is useful for evaluation of urinary bladder cancer with high spatial resolution and less distortion. S-DWI enables to enhance diagnostic ability of FOCUS without image degradation, and might be one of the best combinations.

1613.   Evaluation of endometrial lesion on synthetic FOCUS diffusion weighted imaging
Motoyuki Katayama1, Takayuki Masui1, Kimihiko Sato1, Kei Tsukamoto1, Kenichi Mizuki1, Maho Hayashi1, Tetsuya Wakayama2, and Yuji Iwadate2
1Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan, 2GE Healthcare Japan, Hino, Tokyo, Japan

We evaluated 21 endometrial lesion including 12 endometrial cancer on synthetic DWI calculated from FOCUS DWI. Compared with conventional FOV DWI, FOCUS DWI is more useful for evaluation of endometrial lesion with high spatial resolution and less distortion. S-DWI is able to enhance diagnostic ability of FOCUS without image degradation, and might be one of the best combinations.

1614.   Comparison of mono-exponential, bi-exponential and stretched-exponential models derived parameters in detecting renal cell carcinomas
Wenhui Wang1, Degang Ding2, Dapeng Shi3, Yan Bai3, xiaoyue ma4, and Meiyun Wang3
1Radiology, Henan Provincial People¡¯s Hospital, Zhengzhou, Henan, China, 2Urology, Henan Provincial People¡¯s Hospital, Zhengzhou, Henan, China, 3Henan Provincial People¡¯s Hospital, Zhengzhou, Henan, China, 4Radiology, Zhengzhou University People¡¯s Hospital & Henan Provincial People¡¯s Hospital, Zhengzhou, Henan, China

To evaluate the diagnostic accuracy of mono-exponential, bi-exponential and stretched-exponential models diffusion weighted imaging (DWI) in patients with renal cell carcinoma (RCC). 24 patients with RCC underwent DWI with fifteen b factors (0, 10,30, 50, 70, 100,150,200, 300,400,600, 800,1000,1500,2000 sec/mm2) on a 3.0T MR scanner. The isotropic apparent diffusion coefficient (ADC); the true diffusion coefficient (ADCslow), pseudo-diffusion coefficient (ADCfast), and fraction of perfusion (f) ; the water diffusion heterogeneity index (¦Á) and distributed diffusion coefficient (DDC) derived from the mono-exponential, bi-exponential and stretched-exponential models were calculated in the solid area of tumors and in the corresponding regions of contralateral normal renal parenchyma. Univariate receiver operating characteristic (ROC) analysis was implemented and areas under the curve (AUC) were compared among all parameters using MedCalc (MedCalc Sofware, Mariakerke, Belgium) to determine the largest Yoden index and corresponding sensitivities and specificities in the diagnosis of RCC. The mean ADC, ADCslow and ¦Á value was significantly lower in RCC than in normal renal parenchyma (P < 0.001). ADCfast value was significantly higher in RCC than in normal renal parenchyma (P < 0.001). In the ROC analysis, the AUC for ¦Á was 0.977 and significantly larger than other parameters with a sensitivity of 100% and a specificity of 75.0%. There was a strong correlation between ADC and ADCslow ( r=0.908, P£¼0.001). DWI is a noninvasive MR technique that is sensitive to water molecular diffusion in biological tissue. However, ADC value calculated by a mono-exponential model alone may not be able to accurately reflect water molecular diffusion in vivo because of the influence of the microcirculation of blood in capillaries [1]. Some recent studies have suggested that bi-exponential and stretched-exponential DWI models might provide more accurate information about the water diffusion[2-3] by separating water molecular diffusion from microcirculation and describing the heterogeneity of intravoxel diffusion rates and the distributed diffusion effect. Comparing with parameters derived from mono-exponential and bi-exponential models, the ¦Á derived from stretched-exponential model may provide the most accurate information in the diagnosis of RCC.

1615.   Abdominal diffusion imaging parameters from free-breathing multiple-averaged and finely-sampled decay curves compared to acquisition using active breathing control
Neil Peter Jerome1, Evangelia Kaza1, Matthew R Orton1, James A d'Arcy1, Bernd Kuehn2, Dow-Mu Koh3, David J Collins1, and Martin O Leach1
1Radiotherapy & Imaging, The Institute of Cancer Research, Sutton, London, United Kingdom, 2Healthcare, Siemens AG, Erlangen, Germany, 3Department of Radiology, Royal Marsden Hospital, Sutton, United Kingdom

The blurring from respiratory motion found in free-breathing abdominal diffusion imaging can be difficult to resolve without impacting patient comfort. Sufficient sampling of the diffusion curve may alleviate the need for prospective motion control; though the form of the optimal sampling scheme must reflect the question being asked. We compare diffusion parameters from two alternate free-breathing schemes (32 b-values with no averaging, and 9 b-values with 4 averages) against a 32 b-value sequence acquired under active breathing control, and show lack of significant differences, indicating intended choice of post-processing may be an important consideration in designing abdominal DWI protocols.

1616.   Caloric Intake Influence on Hepatic MR Diffusion Measurement
Feifei Qu1, Pei-Herng Hor1,2, Claudio Arena3, Debra Dees3, and Raja Muthupillar3
1Physics Department, University of Houston, Houston, TX, United States, 2Texas Center for Superconductivity, Houston, TX, United States, 3Diagnostic and Interventional Radiology, St. Luke's Medical Center, Houston, TX, United States

Studies have sought to use changes in hepatic apparent diffusion coefficient (ADC) as an imaging biomarker for the assessment of the degree of fibrosis. In this study, the effect of a high-caloric food intake on ADC was investigated. The result showed that ADC(b = 0,1000s/mm2) and ADC(b = 200,1000s/mm2) increased following a 1090kcal meal ingestion.

1617.   Intravoxel Incoherent Motion MRI of the Healthy Pancreas: Monoexponential and Biexponential Apparent Diffusion Parameters and Age Correlations
Chao Ma1, Li Liu1, Jing Li1, Li Wang1, Luguang Chen1, Yanjun Li1, Yong Zhang2, Shiyue Chen1, and Jianping Lu1
1Radiology, Changhai Hospital of Shanghai, Shanghai, Shanghai, China, 2MR Group, GE Healthcare, Shanghai, China

The age-related proportional changes may also have a significant influence on ADCs in the helthy pancreas.Ideally, multiple b values DWI with intravoxel incoherent motion (IVIM) model should be set up for the separate estimation of tissue perfusion and diffusivity. Thus, the aim of the study was to identify 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 normal pancreas and the age.

1618.   Multiparametric MR Enterography Without the Use of Antiperistaltic Agents: Performance and Interpretation
Amelia Wnorowski1, Flavius Guglielmo1, Robert Ford1, and Donald Mitchell1
1Thomas Jefferson University, Philadelphia, Pennsylvania, United States

MR enterography (MRE) performed without antiperistaltic agents can be as accurate as MRE performed with antiperistaltic agents. The purpose of this educational e-poster is to detail how to perform and interpret MRE without using antiperistaltic agents. The effect of motion artifact on diagnostic confidence can be overcome by using a multiparametric approach. This includes T2-weighted, dynamic postcontrast T1-weighted and diffusion weighted images as well as a multiphasic cine sequence for peristalsis evaluation. This educational e-poster will discuss imaging parameters and interpretation pearls for these various sequences as well as provide sample cases for review.

1619.   Small Bowel Stenosis in Crohn's Disease: Characterizing the "STENOSIS" with MR Enterography
Kai Kinder1, Kenneth Daughters2, and Chris Kuzminski2
1Santa Barbara Cottage Hospital, Santa Barbara, CA, United States, 2Santa Barbara Cottage Hospital, California, United States

Evaluation and management of Crohn’s disease is often clinically difficult, but advances in magnetic resonance enterography (MRE) have helped to overcome a number of obstacles. Specifically, MRE is able to accurately characterize a small bowel stenosis and differentiate one caused by active inflammation from one caused by chronic fibrotic changes, which is an important distinction clinically. This Educational E-Poster will provide radiologists and trainees with the information needed to confidently evaluate a small bowel stenosis on MRE, including an overview of the literature, an introduction of the mnemonic device “STENOSIS”, and sample cases to illustrate all salient features.

1620.   Quantified terminal ileal motility as a biomarker of Crohn’s Disease activity assessed using Magnetic Resonance Enterography: A prospective study
Alex Menys1, Charlotte E Tutein Nolthenius2, Carl Puylaert2, Makanyanga Jesica1, Evelien Gryspeerdt1, Gauraang Bhatnagar1, Nikos Dikaios1, David Atkinson1, Jaap Stoker2, and Stuart A. Taylor1
1UCL, London, UK, United Kingdom, 2AMC, Netherlands, Netherlands

This abstract examines the potential of gastrointestinal motility at the terminal ileum to serve as a biomarker for inflammatory activity in Crohn's disease. In this article, a prospective cohort of 95 patients is examined, collected as part of the VIGOR++ study to examine the role of MR Enterography in the evaluation of Crohn's Disease.

1621.   Highly accelerated 4D radial single breathhold acquisition of the entire gastro-intestinal tract using L1 k-t SPIRiT
Vlad Ceregan1, Jelena Curcic1,2, Andreas Steingoetter1,2, and Sebastian Kozerke1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland

Time-resoved volumetric acquisitions of the entire gastro-intestinal tract are crucial to understanding its function. To achieve sufficient temporal resolutions significant data undersampling is required. For this purpose L1 k-t SPIRiT was implemented in combination with a radial Golden angle stack of stars sampling pattern. Data acquired with an undersampling factor of 15 were obtained during a single breathhold in healthy subjects with good image quality.

1622.   Effect of Weight Loss and Regional Differences in Abdominal Adipose Tissue Hydration
Suresh Anand Sadananthan1, Navin Michael1, Eric Yin Hao Khoo2, Melvin Khee-Shing Leow1,3, Chin Meng Khoo2, Kavita Venkataraman4, Yung Seng Lee1,5, Yap Seng Chong1,6, Peter D. Gluckman1, E. Shyong Tai2, and S. Sendhil Velan7,8
1Singapore Institute for Clinical Sciences, A*STAR, Singapore, 2Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 3Department of Endocrinology, Tan Tock Seng Hospital, Singapore, 4Saw Swee Hock School of Public Health, National University of Singapore, Singapore, 5Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 6Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 7Singapore BioImaging Consortium, A*STAR, Singapore, 8Clinical Imaging Research Centre, A*STAR, Singapore

Weight loss alters the levels of liver, muscle and abdominal fat and also results in increased insulin sensitivity. Earlier studies using indirect measurements of subcutaneous adipose tissue water content have shown increase in the water content following weight loss intervention. Reduced water content is strongly associated with hypertrophic expansion of the adipose tissue. In this study, we have investigated the use of 1H MRS to noninvasively quantify the changes in adipose tissue water content with weight loss intervention. Furthermore, we have looked at the regional differences in the water content in DSAT, SSAT and VAT depots pre- and post-intervention.

1623.   Visualizing and quantifying human fat digestion with IDEAL
Dian Liu1, Helen Louise Parker2, Jelena Curcic1,2, Sebastian Kozerke1, and Andreas Steingoetter1,2
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland

This study uses chemical shift-encoded imaging by IDEAL to visualize and quantify the influence of intragastric stability of fat emulsions on the dynamics and structure of gastric luminal content and the related fat emptying into the duodenum. The different intragastric stability of the emulsions resulted in different structuring of intraluminal content and different emptying patterns, which resulted in bi-phasic and significantly faster emptying of gastric content and highly variable gastric and duodenal fat fractions for the acid unstable emulsion. No temporal effect was detected for duodenal content volume or fat fraction between the emulsions.

1624.   Quantification of Brown Adipose Tissue in DIXON Water-Fat Separation and T2* Mapping
Defeng Wang1, Ka Long Ko1, Steve CN Hui1, Lin Shi2,3, and Winnie CW Chu1
1Dept of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, 2Dept of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, 3Chow Yuk Ho Technology Centre for Innovative Medicine, The Chinese University of Hong Kong, Shatin, NT, Hong Kong

The purpose of this study was to verify the accuracy of using water-fat separation method and T2* mapping to quantify brown adipose tissue. A water-fat separation MRI sequence and T2* MR imaging technique was applied on obese teenagers and control. Fat-fraction signal and T2* mapping were generated with multiecho scanning and specially focused on interscapular-supraclavicular region. Results indicated volume of BAT was significantly less in obese subjects than that in normal controls. The proposed algorithm could accurately measure the volume of BAT in human and could be served as an alternative to detect BAT and WAT.

1625.   Fast 3T Whole Body MR Exam utilizing 2 point DIXON T1 & T2w and streamlined workflow approach
Lloyd Estkowski1, Maggie M Fung2, Ken-Pin Hwang3, and Ersin Bayram3
1Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States, 2Global MR Applications and Workflow, GE Healthcare, New York City, NY, United States,3Global MR Applications and Workflow, GE Healthcare, Houston, TX, United States

STIR T2w, T1w Fast Spin Echo (FSE) and DWI are the most commonly used sequence in whole body MR today, however, long scan time has limited its adoption. In this study, we proposed a fast whole body MR exam that provides 5 contrasts (Fat Sat & non-Fat Sat T1, Fat Sat & non-Fat Sat T2, DWI) in less time compare to conventional WBI. This was achieved by using 2-point DIXON techniques in T2w FSE and T1w LAVA. We also applied streamlined workflow strategies such as shared prescan and auto table movement to further reduce the total scan time to 23 min.

1626.   Improved retinal shape detection using high-resolution MRI compared to partial coherence interferometry
Jan-Willem M Beenakker1,2, Mihai State3, Denis P Shamonin4, Marrie van der Mooren3, Berend C Stoel4, Andrew G Webb1, Gregorius PM Luyten2, and Patricia Piers3
1Department of Radiology, C.J.Gorter Center for High Field MRI, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands, 2Department of Ophthalmology, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands, 3AMO Groningen BV, Groningen, Netherlands, 4Department of Radiology, devision of Image Processing, Leiden University Medical Center, Leiden, Zuid-Holland, Netherlands

Current techniques in ophthalmology, such as PCI (partial coherence interferometry), cannot accurately measure the retinal shape because refraction causes systematic errors for off-axis measurements. We assessed these errors by measuring the left eye of 16 volunteers using high-resolution ocular MRI, which is not influenced by refraction, and PCI. The on-axis data shows the high accuracy of ocular MRI (systematic error 0.08mm), while off-axis measurements show large systematic differences between the techniques. This shows the importance of MRI as the gold-standard for three-dimensional retinal shape characterisation.

1627.   MRI of aerated beverages: intragastric behaviour and role in hunger suppression
Kathryn Murray1, Elisa Placidi1, Ewoud Schuring2, Caroline Hoad1, Wieneke Koppenol2, Luben Arnaudov2, Wendy Blom2, Susan Pritchard1, Simeon Stoyanov2, David Mela2, Penny Gowland1, Robin Spiller3, Harry Peters2, and Luca Marciani3
1Sir Peter Mansfield Imaging Centre, Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom, 2Unilever Research and Development, Unilever, Olivier van Noortlaan 120, 3133 AT Vlaardingen, Netherlands, 3Nottingham Digestive Diseases Biomedical Research Centre, Nottingham University Hospitals, Nottingham, United Kingdom

 
Aerated drinks such as foams have been shown to increase satiety, but intragastric mechanisms have not been explored. This study investigates the intragastric behavior of two foamed beverages with different stabilities compared to a non-aerated liquid control. Total gastric volumes and foam volumes were measured using MRI and correlated to behavioral scores, demonstrating mechanism of hunger suppression.

1628.   Comparison of True Technical Costs of MRI and CT
Alex Lewis1, Andreas Loening1, and Shreyas Vasanawala1
1Department of Radiology, Stanford University, Stanford, CA, United States

Detailed analysis of the multiple variables that contribute to the cost of operating a single 3T magnet was undertaken including capital costs, consumable costs, overhead costs, staffing costs and maintenance/service expenses. The cost per minute of MRI is linear at $3.13 with a prominent increase at 10 minutes accounting for the point of contrast injection, which is the largest incremental cost for an MR exam. The cost of a 15 minute MRI with contrast is $106 versus $99 for a 5 minute CT with contrast (cost is comparable secondary to slightly higher cost of CT contrast compared to gadolinium).

1629.   MRI-compatible motion platform for studying the influence of organ motion on body MRI
Joris Nofiele1, Qing Yuan1, Quinn Torres1, Mohammad Kazem2, Ken Tatebe1, Ivan Pedrosa1,3, and Rajiv Chopra1,3
1Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States, 2Imaging Research, Sunnybrook Research Institute, Toronto, Ontatio, Canada,3Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States

Abdominal MRI is challenging due to respiratory motion. Compensation techniques cannot be easily be compared because of the difficulty in reproducing the same motion with volunteer scans. We report on a custom built MR compatible platform capable of simulating and replaying true organ motion. Operation of the platform within the bore of the scanner did not affect the scanner. Real organ motion was obtained from a scan of a volunteer.T2-mapping showed aliasing with sinusoidal motion and smearing-like artifacts with replayed kidney motion. This platform could enable investigations into motion artifacts for developing correction techniques.

1630.   Ratios of Visceral and Subcutaneous Fat Mass Are Linearly Correlated with Aging
In-Young Lee1, Yunjung Lee1, Jea Seung Kim1, Hee-Sook Jun1, and Jong-Hee Hwang1
1Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Korea

According to previous studies, a possible role of fat accumulation with aging is suspected. Thus, the specific goals of this study were 1) to assess simultaneously whole body subcutaneous and visceral fat, and liver fat on 3 different age groups of mice, and 2) to investigate an age-related association with body fat content. Amongst visceral, subcutaneous and liver fat, and relative ratios between visceral and subcutaneous fat (vfat/subfat), the vfat/subfat ratios were linearly correlated (P<0.05) with aging for a wider span (8-80 weeks) than individual fat mass.