Lung/Mediastinum

Tuesday 2 June 2015

Kerry Hart^1,2, Helen Marshall¹, Neil Stewart¹, Martin Deppe¹, Steve Bianchi³, Rob Ireland², Moira Whyte⁴, David Kiely³, and Jim Wild^1
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).

Markus Weiger¹, Mingming Wu^1,2, Moritz Christoph Wurnig³, David Kenkel³, Wolfgang Jungraithmayr⁴, Andreas Boss³, and Klaas Paul Pruessmann^1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ²Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe, Germany,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.

Zackary I. Cleveland¹, R. Scott Dunn², Cynthia R. Davidson³, Jinbang Guo^1,4, Jason C Woods^1,4, and William D. Hardie^3
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.

Andrew D. Hahn¹, Nara S. Higano^2,3, Laura L. Walkup², Xuefeng Cao^2,4, Robert P. Thomen^2,3, Jean A. Tkach⁵, Charles L. Dumoulin^6,7, Kevin M. Johnson¹, Scott K. Nagle^1,8, Jason C. Woods^2,3, and Sean B. Fain^1,8
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.

Jean Delacoste^1,2, Jerome Chaptinel^1,2, Catherine Beigelman¹, Davide Piccini^3,4, Alain Sauty^5,6, and Matthias Stuber^1,2
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.

Grzegorz Bauman¹, Orso Pusterla¹, and Oliver Bieri^1
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.

Anne Schmieder¹, Jochen Keupp², Huiying Zhang¹, Todd Williams¹, John Stacy Allen¹, Xiaoxia Yang¹, Erik Storrs¹, Krishna Paranandi¹, Elizabeth Wagner³, and Gregory Lanza^1
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.

Noriko Aida¹, Kumiko Nozawa¹, Yuta Fujii¹, Mikako Enokizono¹, Masahiko Sato², Koki Kusagiri², Yasutake Muramoto², Yuichi Suzuki², Jun Shibasaki³, Katsuaki Toyoshima³, Katsutoshi Murata⁴, and David Grodzki^5
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.

Andreas Voskrebenzev^1,2, Lena Becker^1,2, Marcel Gutberlet^1,2, Christian Schönfeld^1,2, Julius Renne^1,2, Jan Hinrichs^1,2, Till Kaireit^1,2, Tobias Welte^2,3, Frank Wacker^1,2, Jens Gottlieb^2,3, and Jens Vogel-Claussen^1,2
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.

Andrew D. Hahn¹, Xuefeng Cao^2,3, Nara S. Higano^2,4, Jean A. Tkach⁵, Robert P. Thomen^2,4, Scott K. Nagle^1,6, Gregory Lee², Kevin M. Johnson¹, Sean B. Fain^1,6, and Jason C. Woods^2,4
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.

Gowtham Gajawada^1,2, Tao Li¹, Marcus J Couch^1,2, Matthew S Fox^3,4, and Mitchell Albert^1,2
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.

Marta Tibiletti¹, Detlef Stiller², Volker Rasche¹, and Andrea Bianchi^2
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.

Alexandr A Khrapitchev¹, James R Larkin¹, Stavros Melemenidis¹, Konstantinos Papoutsis², Peter Thelwall³, and Nicola R Sibson^1
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.

Jascha Zapp¹, Sebastian Domsch¹, and Lothar R. Schad^1
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.

Xiuli Tao¹, Han Ouyang¹, Li Liu¹, Feng Ye¹, Ying Song¹, Zihua Su², Xiao Xu², and Ning Wu^1
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).

Sampada Bhave¹, Sajan Goud Lingala², John Newell¹, Alejandro Comellas¹, and Mathews Jacob^1
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.

Grzegorz Bauman¹ and Oliver Bieri^1
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.

Joris Tchouala Nofiele¹, Weiran Cheng², Inga E Haedicke², Tameshwar Ganesh¹, Xiao-an Zhang², and Hai-Ling Margaret Cheng^1,3
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.

Alexander Weller¹, Sharon L Giles², Veronica A Morgan², David Collins¹, David M Higgins³, and Nandita M de-Souza^1
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.

Mikayel Dabaghyan¹, Iga Muradyan^2,3, Alan Hrovat¹, James P. Butler^2,3, Angelos Kyriazis^2,3, Mirko I. Hrovat¹, and Samuel Patz^2,3
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.

Xiuli Tao¹, Han Ouyang¹, Li Liu¹, Feng Ye¹, Ying Song¹, Xiao Xu², Zihua Su², and Ning Wu^1
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.

Jinbang Guo^1,2, Xingan Wang³, Anne K. Perl⁴, Zackary I. Cleveland¹, Randy Giaquinto⁵, Andrew E. Gelman³, and Jason C. Woods^1,2
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.

Joshua S. Greer^1,2, Xinzeng Wang², Ivan Pedrosa^2,3, and Ananth J. Madhuranthakam^2,3
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.

Cord Bastian Meyer¹, Stefan Weick², Michael Völker³, Frederick Mantel², Felix Breuer^1,3, and Peter Michael Jakob^1,3
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.

Marta Tibiletti¹, Jan Paul², Andrea Bianchi³, Stefan Wundrak², Wolfgang Rottbauer², Detlef Stiller³, and Volker Rasche^1,2
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.

John P. Mugler, III¹, Samuel W. Fielden², Craig H. Meyer², Talissa A. Altes¹, G. Wilson Miller¹, Alto Stemmer³, Josef Pfeuffer³, and Berthold Kiefer^3
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.

Iga Muradyan¹, Raja-Elie Abdulnour^2,3, Angelos Kyriazis¹, Samuel Patz¹, and Bruce Levy^2,3
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.

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 Barr^1
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).

Khadija Sheikh^1,2, Dante Capaldi^1,2, Sarah Svenningsen^1,2, David G McCormack³, and Grace Parraga^1,2
1Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada, ²Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada, 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.

Hisanobu Koyama¹, Yoshiharu Ohno¹, Shinichiro Seki¹, Takeshi Yoshikawa¹, Sumiaki Matsumoto¹, Katsusuke Kyotani², Masao Yui³, Hitoshi Yamagata³, and Kazuro Sugimura^1
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.

Orso Pusterla¹, Oliver Bieri¹, Gregor Sommer², and Grzegorz Bauman^1
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.

Evangelia Kaza¹, David J Collins¹, Richard Symonds-Tayler¹, Fiona McDonald², Helen A McNair³, Erica Scurr², Dow-Mu Koh², and Martin O Leach^1
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).

Gregor Sommer¹, Mark Wiese², Nicolin Hainc¹, Jens Bremerich¹, Oliver Bieri³, and Grzegorz Bauman^3
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.

Samuel Patz^1,2, Iga Muradyan^1,2, Ritu R. Gill^1,2, Ravi T. Seethamraju³, Aaron B. Waxman^1,2, and James P. Butler^1,2
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).

Hyperpolarized Gas Imaging

Tuesday 2 June 2015

Neil James Stewart¹ and Jim Michael Wild^1
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.

Rohan S Virgincar¹, Simone Degan^2,3, Matthew S Freeman⁴, Mu He⁵, and Bastiaan Driehuys^3
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.

Scott H. Robertson¹, Rohan S. Virgincar², Mu He³, S. Sivaram Kaushik², Matthew S. Freeman¹, and Bastiaan Driehuys^4
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.

Kun Qing¹, Nicholas J. Tustison¹, Tallisa A. Altes¹, Kai Ruppert^1,2, Jaime F. Mata¹, G. Wilson Miller¹, Steven Guan¹, Iulian C. Ruset^3,4, F. William Hersman^3,4, and John P. Mugler, III^1
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.

Graham Norquay¹, Neil Stewart¹, and Jim Wild^1
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

Andrea Capozzi¹, Christophe Roussel², Arnaud Comment¹, and Jean-Noel Hyacinthe^3
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.

Neil James Stewart¹, Helen Marshall¹, and Jim Michael Wild^1
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.

Krzysztof Wawrzyn^1,2, Alexei Ouriadov¹, Elaine Hegarty¹, Susannah Hickling³, and Giles Santyr^1,4
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.

Brandon Zanette^1,2, Matthew S Fox³, Ozkan Doganay^3,4, Elaine Hegarty^2,3, and Giles E Santyr^1,2
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.

Kun Qing¹, Talissa A. Altes¹, Y. Michael Shim¹, Nicholas J. Tustison¹, Kai Ruppert^1,2, Chengbo Wang^1,3, Jaime F. Mata¹, G. Wilson Miller¹, Steven Guan¹, Iulian C. Ruset^4,5, F. William Hersman^4,5, and John P. Mugler, III^1
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.

Clementine Lesbats¹, Anthony Habgood², David ML Lilburn³, Joseph S Six⁴, Gisli Jenkins², Galina E Pavlovskaya¹, and Thomas Meersmann^1
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.

Steven Guan¹, Kun Qing¹, Tally Altes¹, John Mugler III¹, Iulian Ruset^2,3, Deborah Froh¹, Grady Miller¹, James Brookeman¹, and Jaime Mata^1
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.

Ozkan Doganay^1,2, Trevor Wade², Elaine Hegarty², Krzysztof Wawrzyn², Rolf F. Schulte³, Charles McKenzie^1,2, and Giles Santyr^2,4
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.

Robert Paul Thomen^1,2, James D Quirk³, David Roach¹, Tiffany Egan-Rojas¹, Kai Ruppert¹, Iulian Ruset⁴, Talissa Altes⁵, Dmitriy Yablonskiy³, and Jason C Woods^1,2
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.

Zhiying Zhang¹, Haidong Li¹, Xianping Sun¹, Xiuchao Zhao¹, Chaohui Ye¹, and Xin Zhou^1
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.

Felix C Horn¹, Madhwesha Rao¹, Neil J Stewart¹, Helen Marshall¹, Juan Parra-Robles¹, and Jim M Wild^1
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.

Marcus J. Couch^1,2, Iain K. Ball², Tao Li², Matthew S. Fox^3,4, Birubi Biman^5,6, and Mitchell S. Albert^1,2
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.

David G. Mummy¹, Robert P. Thomen², Stanley J. Kruger³, Alfonso Rodriguez³, Robert V. Cadman³, Nizar N. Jarjour⁴, Loren C. Denlinger⁴, Ronald L. Sorkness^4,5, Mark L. Schiebler⁶, Jason C. Woods⁷, and Sean B. Fain^3,6
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.

Kai Ruppert^1,2, Bora Sul³, Kun Qing², Vineet Rakesh³, Craig H Meyer², John P Mugler III², Anders Wallqvist³, Michael J Morris⁴, Talissa A Altes², and Jaques Reifman^3
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.

Paul J.C. Hughes¹, Bilal A. Tahir^1,2, Felix C. Horn¹, Helen Marshall¹, Rob H. Ireland^1,2, and James M. Wild^1
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.

Graham Norquay¹, Neil Stewart¹, and Jim Wild^1
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.

Hooman Hamedani¹, Stephen Kadlecek¹, Yi Xin¹, Hoora Shaghaghi¹, Sarmad Siddiqui¹, Milton Rossman², and Rahim R. Rizi^1
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.

Wolfgang Loew¹, Robert Thomen², Ron Pratt¹, Zackary Cleveland², Charles Dumoulin¹, Jason Woods², and Randy O Giaquinto^1
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.

Hepatobilliary

Tuesday 2 June 2015

S Bawden^1,2, MC Stephenson³, K Hunter⁴, M Taylor⁵, L Marciani¹, PG Morris², IA Macdonald⁶, GP Aithal¹, and PA Gowland^2
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

Sharon Janssens¹, Marina D.B. Sabbadini¹, Klaas Nicolay¹, and Jeanine J. Prompers^1
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.

S Bawden^1,2, M Stephenson³, K Hunter⁴, M Taylor⁵, PG Morris², L Marciani¹, IA Macdonald⁶, GP Aithal¹, and PA Gowland^2
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.

Sonia Isabel Goncalves^1,2, Filipe Caseiro Alves^2,3, and Miguel Castelo Branco^1,2
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.

Paul Begovatz¹, Sabine Kahl^1,2, Peter Nowotny¹, Bettina Nowotny^1,2, and Michael Roden^1,2
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.

Utaroh Motosugi^1,2, Diego Hernando¹, Peter Bannas^1,3, and Scott B. Reeder^1,4
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.

Anita Kiani¹, Elise Bannier¹, Giulio Gambarota^2,3, Hervé Saint-Jalmes^2,3, and Yves Gandon^1
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.

MINGMEI GE¹, JING ZHANG², ZIHENG ZHANG², and XINHUAI WU^1
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.

Curtis N Wiens¹, Alan B McMillan¹, Nathan S Artz^1,2, Rashmi Agni³, Nikolaus Szeverenyi⁴, William Haufe⁴, Catherine Hooker⁴, Meng Yin⁵, Guilherme M Campos⁶, Claude Sirlin⁴, and Scott B Reeder^1,7
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.

Jurgen Henk Runge¹, Ulrich H Beuers², Aart J Nederveen¹, and Jaap Stoker^1
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.

Jin Wang¹, Lin Luo², Yunhong Shu³, Hong Shan¹, and Bingjun He^1
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

Florine SW van der Wolf - de Lijster¹, Andrew J Patterson¹, Martin J Graves¹, and David J Lomas^1
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.

WEIMIN AN¹, JING ZHANG², and HUI XIE^1
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.

Jun Chen¹, Meng Yin¹, Jayant Talwalkar¹, Kevin Glaser¹, Thomas Smyrk¹, and Richard Ehman^1
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.

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. Venkatesh^1
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.

Oliver J. Gurney-Champion^1,2, Remy Klaassen^3,4, Jaap Stoker¹, Arjan Bel², Hanneke W.M. van Laarhoven³, Aart J. Nederveen¹, and Sonia I. Goncalves^5
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.

Dean Kolnick¹, Kang Wang², Andrew Phelps¹, Pauline Worters², John Mackenzie¹, and Jesse Courtier^1
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.

Nieun Seo¹, Seong Joon Park¹, Bohyun Kim¹, Chang Kyung Lee¹, Jisuk Park¹, In Seong Kim², and Berthold Kiefer^3
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.

Jia Ning¹, Bida Zhang², Honsum Li¹, Dan Zhu¹, Feng Huang², Shuo Chen¹, Peter Koken³, Jouke Smink⁴, and Huijun Chen^1
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.

Morisaka Hiroyuki¹, Utaro Motosugi^1,2, Shintaro Ichikawa¹, Katsuhiro Sano¹, Tomoaki Ichikawa¹, Masayuki Nakano³, and Hiroshi Onishi^1
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.

Helen Cheung¹, Paul Karanicolas², Chirag Patel¹, Natalie Coburn², Masoom A Haider¹, Calvin Law², and Laurent Milot^1
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%).

Atsushi Higaki¹, Tsutomu Tamada¹, Akira Yamamoto¹, Yasufumi Noda¹, Kazuya Yasokawa¹, and Katsuyoshi Ito^1
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.

Stephen Lenhard¹, Debra Paul², Mally Lev³, Lindsey Webster⁴, Christopher Goulbourne⁵, Richard Peterson⁵, Richard Miller⁶, and Beat Jucker^1
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.

Hui Zhang¹, Ed X. Wu^2,3, and Hua Guo^1
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.

Miriam Klauss¹, Philipp Mayer¹, Klaus Maier-Hein², Frank Bergmann³, Thilo Hackert⁴, Lars Grenacher¹, and Bram Stieltjes^5
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.

Scott A Reid¹, Kevin F King², Florine van der Wolf-de Lijster³, Martin J Graves³, Lloyd Estkowski², and David J Lomas^3
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

CHUNMEI MA¹, Ailian Liu¹, YE LI¹, LIHUA CHEN¹, and HEQING WANG^1
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).

Yukihisa Takayama¹, Akihiro Nishie², Yoshiki Asayama², Kousei Ishigami², Yasuhiro Ushijima², Daisuke Okamoto², Nobuhiro Fujita², Koichiro Morita², Tomoyuki Okuaki³, and Hiroshi Honda^2
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.

Jin Ah Kim¹, Jon D. Blumenfeld^2,3, Silvina P. Dutruel¹, Nanda Deepa Thimmappa Deepa Thimmappa¹, Warren O. Bobb², Stephanie Donahue², Ashley E. Giambre⁴, and Martin R. Prince^1
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.

Matthew R. Smith¹, Alejandro Roldan-Alzate¹, Oliver Wieben^1,2, Scott B. Reeder^1,2, and Christopher J. Francois^1
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.

Hiroyoshi Isoda¹, Koji Fujimoto¹, Shigeki Arizono:¹, Akihiro Furuta¹, Takayuki Yamamoto¹, Yasutaka Fushimi¹, Aki Kido¹, Kaori Togashi¹, and Naotaka Sakashita^2
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.

Renal, Pelvis & Fetal

Tuesday 2 June 2015

Jing Guo-dong¹, Wang Li², Wang Jian², and LU Jian-ping^2
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.

Yoshiko Ueno¹, Satoru Takahashi², Yoshiharu Ohno^2,3, Katsusuke Kyotani⁴, Masao Yui⁵, Yoshimori kassai⁵, Kazuhiro Kitajima⁶, and Kazuro Sugimura^1
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.

Thomas de Perrot¹, Bénédicte M A Delattre¹, Lindsey A Crowe¹, Iris Friedli¹, Marc Pusztaszeri², Jean-Christophe Tille², Christophe Iselin³, and Jean-Paul Vallée^1
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.

Soha Said Ramadan¹, Pablo Caro Dominguez^1,2, Jorge H. Davila^1,2, Melissa Valdez Quintana^1,2, Julie Hurteau-Miller^1,2, David Grynspan^2,3, Felipe Moretti^2,4, and Elka Miller^1,2
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.

Reut Avni¹, Joel Garbow², and Michal Neeman^1
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.

Skorn Ponrartana¹, Sherin U Devaskar², Jonathan M Chia³, Vidya Rajagopalan⁴, Hollie A Lai¹, David Miller⁵, and Vicente Gilsanz^1
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.

Pablo Garcia-Polo¹, Borjan Gagoski², Bastien Guerin³, Eric Gale³, Elfar Adalsteinsson^4,5, P. Ellen Grant², and Lawrence L. Wald^3,5
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.

Nicholas Hilliard¹, Rebecca Baker¹, Andrew Patterson¹, Martin Graves¹, Christoph Lees², Pat Set¹, and David J Lomas^1
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.

Katsumi Kose¹, Yosuke Otake¹, Akiyoshi Nagata¹, Tomoyuki Haishi², and Shigehito Yamada^3
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.

Rebecca Hawkes¹, Andrew Patterson², Andrew Priest², Martin J Graves², Nicholas Hilliard², Patricia Set¹, and David Lomas^1
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.

Hui Zhao¹, Tianyi Qian², Yong Wu¹, Shuwei Liu³, Lianxiang Xiao¹, and Xiangtao Lin^1,3
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.

Mayumi Takeuchi¹, Kenji Matsuzaki¹, and Masafumi Harada^1
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.

Sajan Andrews¹, Qing Yuan¹, April Bailey¹, Naira Muradyan², Robert Staruch^1,3, Rajiv Chopra^1,4, and Ivan Pedrosa^1,4
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.

Gigin Lin¹, Yu-Ting Huang¹, Koon-Kwan Ng¹, and Shu-Hang Ng^1
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.

Mayumi Takeuchi¹, Kenji Matsuzaki¹, and Masafumi Harada^1
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).

Mayumi Takeuchi¹, Kenji Matsuzaki¹, and Masafumi Harada^1
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.

Sung Bin Park¹, Jong Beum Lee², and Hyun Jeong Park^2
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.

Tiing Yee Siow¹, Yu-Chun Lin¹, and Gigin Lin^1
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.

Andreas M. Loening¹, Pejman Ghanouni¹, Marcus T. Alley¹, and Shreyas S. Vasanawala^1
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.

Steven M Shea¹, Abbie Diak², Murat Surucu², Matthew Harkenrider², and Joseph M Yacoub^1
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.

Andreas M. Loening¹, Manojkumar Saranathan¹, Daniel V. Litwiller², Ann Shimakawa², Lloyd Estkowski², and Shreyas S. Vasanawala^1
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.

El-Sayed H. Ibrahim^1,2, Joseph Cernigliaro², Mellena Bridges², Robert Pooley², and William Haley^2
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.

Han-Mei Zhang¹, Xiao Lv², Pan-Li Zuo³, Niels Oesingmann⁴, and Bin Song^1
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.

Jon Thacker¹, Huan Tan², Lu-Ping Li^2,3, Wei Li^2,3, Ying Zhou³, Orly Kohn², Stuart Sprague^2,3, and Pottumarthi Prasad^2,3
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.

Iris Friedli¹, Lindsey Alexandra Crowe¹, Lena Berchtold², Solange Moll³, Karine Hadaya⁴, Pierre-Yves Martin⁴, Sophie De Seigneux⁴, and Jean-Paul Vallée^1
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.

Lu-Ping Li¹, Wei Li¹, Jon Thacker¹, Huan Tan¹, Ying Zhou², Orly Kohn³, Stuart Sprague⁴, and Pottumarthi V. Prasad^1
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.

Jon Thacker¹, Lu-Ping Li^2,3, Wei Li^2,3, Stuart Sprague^2,3, and Pottumarthi Prasad^2,3
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.

Nainesh Parikh¹, Justin Ream¹, Hoi Cheung Zhang¹, Tobias Block², Hersh Chandarana¹, and Andrew Rosenkrantz^1
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.

General Leung^1,2, Nan Jiang³, Anthony A Sheen¹, Serge Jothy⁴, Darren A Yuen^2,5, and Anish Kirpalani^1,2
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.

Yung Chieh Chang¹, Yi-Ying Wu^1,2, Jyh-Wen Chai¹, and Clayton Chi-Chang Chen^1
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.

Gavin Low^1,2, Nicola Eve Owen³, Ilse Joubert¹, Andrew J Patterson¹, Kevin J Glaser⁴, Martin J Graves¹, Graeme J.M. Alexander³, and David J Lomas^1
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.

Ting Chen^1,2, Yuki Mori^1,2, Zhenyu Cheng^1,2, Soyoung Lee¹, Kai Wang¹, Barry Ripley¹, Tadamitsu Kishimoto¹, Chizuko Inui-Yamamoto^1,2, Fuminori Sugihara¹, Noriko Kitagaki¹, Yoshiyuki Tago³, Shinichi Yoshida³, Kohji Ohno⁴, and Yoshichika Yoshioka^1,2
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.

James Glockner¹ and Christine Lee^1
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.

Jorge Chacon-Caldera¹, Raffi Kalayciyan¹, and Lothar R Schad^1
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.

Paul de Heer¹, Jacqueline T Jonker², Evelien H van Rossenberg², Marten A Engelse², Trea CM Streefland³, Ton J Rabelink², Andrew G Webb¹, Patrick CN Rensen^3,4, Hildo J Lamb⁵, and Aiko PJ de Vries^2
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.

Yuan Xie¹, Yanjun Li¹, Dandan Zheng², Yong Zhang³, and Guangming Lu^1
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 ADC_T and F_P differed significantly among eGFR levels. Cortical F_P 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.

Greg O Cron^1,2, Jean-François Thibodeau^1,2, Gerd Melkus^1,2, Anthony Carter², Ian G Cameron^1,2, Nicola Schieda^1,2, Wael Shabana^1,2, and Chris Kennedy^1,2
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.

Yasufumi Noda¹, Katsuyoshi Ito¹, Tsutomu Tamada¹, Akira Yamamoto¹, Kazuya Yasokawa¹, and Atsushi Higaki^1
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.

Tao Ren¹, Hua Li Chen¹, Li Pan Zuo², Thorsten Feiweier³, Niels Oesingmann⁴, and Wen Shen^1
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.

Eli Eikefjord^1,2, Erling Andersen³, Jan Ankar Monssen¹, Erlend Hodneland⁴, Erik Hanson⁵, Arvid Lundervold^1,4, and Jarle Rørvik^1,2
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.

Sneha Prakash Potdar¹, Manoj G Bhosale^1,2, Shivaprasad Ashok Chikop¹, Shaikh Imam¹, Antharikashanagar Bellappa Sachin Anchan¹, and Sairam Geethanath^1
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

Florian Lietzmann¹, Mathias Düsberg¹, and Lothar R. Schad^1
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.

Jorge Chacon-Caldera¹ and Lothar R Schad^1
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.

William Jeffrey Triffo¹ and Youngkyoo Jung^2
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.

Susie Clarke¹, James F Meaney¹, and Andrew J Fagan^1
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.

Virendra Kumar¹, Pawan Kumar¹, Khushpreet Singh², N R Jagannaathan¹, and Ajeet Kumar^2
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.

Sung Bin Park^1
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.

Veerle Kersemans¹, Philip D Allen¹, John S Beech¹, Stuart Gilchrist¹, Paul Kinchesh¹, and Sean C Smart^1
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.

Body DWI, Technical Development & Contrast

Tuesday 2 June 2015

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 Stralen^3
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.

Daniel V Litwiller¹, James F Glockner², and Ersin Bayram^3
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.

Saikat Sengupta^1,2, David S Smith^1,2, and E. Brian Welch^1,2
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.

Laura Smith¹, Marco Borri¹, Araminta EW Ledger¹, Craig Cummings¹, Maria A Schmidt¹, and Martin O Leach^1
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.

Laura Smith¹, Araminta EW Ledger¹, Marco Borri¹, Craig Cummings¹, Maria A Schmidt¹, and Martin O Leach^1
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.

Lizhi Xie¹, Bing Wu¹, Nan Hong², Yingkui Zhang¹, and Zhenyu Zhou^1
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.

Myriam Diaz Martinez¹, Henry H Ong¹, Masoud Ghamari-Langroudi², Aliya Gifford^1,3, Roger Cone², and E Brian Welch^1
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.

Seung-Man Yu¹ and Hyeon-Man Baek^2
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.

Hasan Alsaid¹, Mary V Rambo¹, Tinamarie Skedzielewski¹, Ruth R Osborn², Alicia M Davis M Davis², William Rumsey², and Beat M Jucker^1
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.

Denise Welsh-McCracken¹, Yvonne Van Gessel¹, Dierdre Scully², Jacob Hesterman², and Paul J McCracken^1
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.

Gangchea Lee¹, Minjung Kim², and Thomas Neuberger^1,3
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.

Henry H. Ong^1,2, Corey D. Webb³, Marnie L. Gruen³, Alyssa H. Hasty³, John C. Gore^1,2, and E. Brian Welch^1,2
1Vanderbilt University Institute of Imaging 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 B0 in agreement with previous reports.

Oscar Gustafsson^1,2, Mikael Montelius¹, and Maria Ljungberg^1,2
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.

Harri Merisaari^1,2, Hanne Hakkarainen³, Heidi Liljenbäck^1,4, Helena Ahtinen^1,4, Heikki Minn⁵, Matti Poutanen^4,6, Anne Roivainen^1,4, Timo Tiimatainen³, and Ivan Jambor^7
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 ADC_m, ADC_s, and ADC_k. Stretched exponential and kurtosis models showed better fit to DWI data than the mono-exponential model and presented with good repeatability.

Hadrien Dyvorne¹ and Priti Balchandani^1
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.

Gregory Lemberskiy^1,2, Dmitry S Novikov¹, Henry Rusinek¹, Els Fieremans¹, and Andrew Rosenkrantz^1
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.

Sila Kurugol¹, Moti Freiman¹, Onur Afacan¹, and Simon K Warfield^1
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.

Moritz C Wurnig¹, David Kenkel¹, Lukas Filli¹, and Andreas Boss^1
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.

Wei Liu¹, Himanshu Bhat², Elisabeth Weiland³, Dingxin Wang⁴, Thomas Beck³, Stephen F. Cauley⁵, and David A. Porter^6
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.

Maggie M Fung¹, Wu Gaohong², Lloyd Estkowski³, Dan Xu², Scott Hinks², and Ersin Bayram^4
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.

Alexander D. Cohen¹, Mark D. Hohenwalter¹, and Kathleen M. Schmainda^1,2
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.

Vahid Taimouri¹, Moti Freiman¹, and Simon K Warfield^1
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.

Kentaro Yamada¹, Hiroshi Shinmoto¹, Seigo Ito², Hiroo Kumagai², Tatsumi Kaji¹, and Koichi Oshio^3
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.

Lizhi Xie¹, Bing Wu¹, Ning Wu², Xiaocheng Wei¹, and Zhenyu Zhou^1
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.

James L. Patrick¹, Perry J. Pickhardt¹, Hyungseok Jang¹, Scott B. Perlman¹, and Alan B. McMillan^1
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.

Motoyuki Katayama¹, Takayuki Masui¹, Kimihiko Sato¹, Kei Tsukamoto¹, Kenichi Mizuki¹, Maho Hayashi¹, Tetsuya Wakayama², and Yuji Iwadate^2
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.

Motoyuki Katayama¹, Takayuki Masui¹, Kimihiko Sato¹, Kei Tsukamoto¹, Kenichi Mizuki¹, Maho Hayashi¹, Tetsuya Wakayama², and Yuji Iwadate^2
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.

Wenhui Wang¹, Degang Ding², Dapeng Shi³, Yan Bai³, xiaoyue ma⁴, and Meiyun Wang^3
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.

Neil Peter Jerome¹, Evangelia Kaza¹, Matthew R Orton¹, James A d'Arcy¹, Bernd Kuehn², Dow-Mu Koh³, David J Collins¹, and Martin O Leach^1
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.

Feifei Qu¹, Pei-Herng Hor^1,2, Claudio Arena³, Debra Dees³, and Raja Muthupillar^3
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.

Chao Ma¹, Li Liu¹, Jing Li¹, Li Wang¹, Luguang Chen¹, Yanjun Li¹, Yong Zhang², Shiyue Chen¹, and Jianping Lu^1
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.

Amelia Wnorowski¹, Flavius Guglielmo¹, Robert Ford¹, and Donald Mitchell^1
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.

Kai Kinder¹, Kenneth Daughters², and Chris Kuzminski^2
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.

Alex Menys¹, Charlotte E Tutein Nolthenius², Carl Puylaert², Makanyanga Jesica¹, Evelien Gryspeerdt¹, Gauraang Bhatnagar¹, Nikos Dikaios¹, David Atkinson¹, Jaap Stoker², and Stuart A. Taylor^1
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.

Vlad Ceregan¹, Jelena Curcic^1,2, Andreas Steingoetter^1,2, and Sebastian Kozerke^1
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.

Suresh Anand Sadananthan¹, Navin Michael¹, Eric Yin Hao Khoo², Melvin Khee-Shing Leow^1,3, Chin Meng Khoo², Kavita Venkataraman⁴, Yung Seng Lee^1,5, Yap Seng Chong^1,6, Peter D. Gluckman¹, E. Shyong Tai², and S. Sendhil Velan^7,8
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.

Dian Liu¹, Helen Louise Parker², Jelena Curcic^1,2, Sebastian Kozerke¹, and Andreas Steingoetter^1,2
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ²Division of Gastroenterology and Hepatology, University 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.

Defeng Wang¹, Ka Long Ko¹, Steve CN Hui¹, Lin Shi^2,3, and Winnie CW Chu^1
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.

Lloyd Estkowski¹, Maggie M Fung², Ken-Pin Hwang³, and Ersin Bayram^3
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.

Jan-Willem M Beenakker^1,2, Mihai State³, Denis P Shamonin⁴, Marrie van der Mooren³, Berend C Stoel⁴, Andrew G Webb¹, Gregorius PM Luyten², and Patricia Piers^3
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.

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 Marciani^3
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.

Alex Lewis¹, Andreas Loening¹, and Shreyas Vasanawala^1
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).

Joris Nofiele¹, Qing Yuan¹, Quinn Torres¹, Mohammad Kazem², Ken Tatebe¹, Ivan Pedrosa^1,3, and Rajiv Chopra^1,3
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.

In-Young Lee¹, Yunjung Lee¹, Jea Seung Kim¹, Hee-Sook Jun¹, and Jong-Hee Hwang^1
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.