Yoshiharu Ohno^1,2, Mizuho Nishio¹, Hisanobu Koyama^1,2, Takeshi Yoshikawa¹, Sumiaki Matsumoto¹, Daisuke Takenaka¹, Katsusuke Kyotani², Nobukazu Aoyama², Hideaki Kawamitsu², Makoto Obara³, Marc van Cauteren⁴, Kenya Murase⁵, and Kazuro Sugimura^1
1Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Radiology, Kobe University Hospital, Kobe, Hyogo, Japan, ³Philips Electronics Japan, Tokyo, Japan, ⁴Philips Healthcare Asia Pacific, Tokyo, Japan, ⁵Department of Medical Engineering, Division of Allied Health Sciences, Osaka University Graduate School of Medicine, Suita, Osaka, Japan

In the last several years, dynamic CE-perfusion MRI and time-resolved CE-MR angiography have been put forward as new techniques for quantitative and qualitative assessment of pulmonary vascular diseases. However, there have been no reports on the potential of perfusion MRI and time-resolved MR angiography for assessment of therapeutic effects on CTEPH patients. We hypothesized that dynamic CE-perfusion MRI has equal to or better potential for therapeutic assessment than others in CTEPH patients. The aim of our study was therefore to directly compare the therapeutic effect assessment capability of CE-MDCT, time-resolved CE-MR angiography and dynamic CE-perfusion MRI for CTEPH patients.

Kang Wang¹, Ma. Daniela Cornejo², Dan W. Rettmann³, James H. Holmes¹, A. Muñoz del Río^2,4, Frank R. Korosec^2,4, Jean H. Brittain¹, and Scott K. Nagle^2,4
1Global Applied Science Laboratory, GE Healthcare, Madison, WI, United States, ²Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, ³Global Applied Science Laboratory, GE Healthcare, Rochester, MN, United States, ⁴Radiology, University of Wisconsin-Madison, Madison, WI, United States

3D dynamic contrast enhanced (DCE) pulmonary perfusion imaging for simultaneous evaluation of vascular anatomy and a dynamic assessment of parenchymal microvascular enhancement has been a long sought after application and is finally becoming achievable due to recent advances in rapid imaging. However, it poses challenges for the required resolution in the spatial-temporal domain. In this work, we demonstrate the feasibility of using the DISCO (Differential Subsampling with Cartesian Ordering) technique for DCE pulmonary perfusion to achieve the necessary high spatial-temporal resolution for this application.

Jim M Wild¹, Martin H Deppe¹, Juan Parra-Robles¹, Smitha Rajaram¹, David Kiely¹, Charlie Elliot¹, and Helen Marshall^1
1University of Sheffield, Sheffield, Yorkshire, United Kingdom

Contrast enhanced (CE) lung perfusion 1H MRI provides volumetric information on pulmonary perfusion. Hyperpolarised 3He MRI provides regional information on ventilation heterogeneity and is sensitive to alveolar oxygen partial pressure. Oxygen enhanced 1H MRI is also sensitive to ventilation and perfusion if it is assumed that the signal enhancement originates from oxygen dissolved in the pulmonary blood compartment. These three complementary functional lung MRI techniques have yet to be tested side by side in-vivo. In this study the methods are compared in a patient with Chronic Thromboembolic Pulmonary Hypertension (CTEPH) whose pulmonary vascular bed shows significant heterogeneity and V/Q mismatch.

Jie Jane Cao^1,2, Yi Wang^1,3, Kathy Mcgrath¹, Nora Ngai¹, Joshua cheng¹, and Philip Marcus^4
1Research, St Francis Hospital, Roslyn, NY New York, United States, ²Cardiology, State University of New York at Stony Brook, Stony Brook, NY New York, United States, ³Bioengineer, State University of New York at Stony Brook, Stony Brook, NY New York, United States, ⁴Medicine, St Francis Hospital, Roslyn, NY New York, United States

We investigated the lung perfusion response to adenosine challenge using lung perfusion quantitation by MRI in 26 volunteers. The absolute lung perfusion was increased by about 2 folds on average during adenosine infusion. Perfusion augmentation was achieved in all lung fields. Reduced lung perfusion was associated with impaired pulmonary function test at rest and during stress. Our findings suggest that quantitative assessment of pulmonary perfusion reserve is feasible using lung perfusion quantitation by MRI.

Jan Hansmann¹, Christian Fink¹, Frank G. Zoellner², Thomas Henzler¹, Mathias Meyer¹, Miriam Reicher¹, Gerald Weisser¹, Stefan O. Schoenberg¹, and Ulrike I. Attenberger^1
1Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Mannheim, BW, Germany, ²Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Mannheim, BW, Germany

Dual Energy CT allows the generation of iodine perfusion maps. This is however not perfusion imaging in the classical sense but rather a static display of iodine based contrast agent in the lung parenchyma. Correlation of static dual energy CT (DECT) derived iodine maps with parameter maps derived from time resolved quantitative pulmonary perfusion MRI showed a high visual, although not statistically significant, correlation between the two modalities.

Yulin V Chang¹, James D Quirk¹, Francesca Pennati², Ramsey Hachem³, Andrea Aliverti², and Jason C Woods^1
1Radiology, Washington University, Saint Louis, MO, United States, ²Biomedical Engineering, Politecnico di Milano, Milan, Italy, ³Internal Medicine, Washington University, St. Louis, MO, United States

We present our preliminary results on quantification of pulmonary ventilation using proton magnetic resonance imaging (MRI) of the lung at different volumes. Images were acquired at 1.5 T field using volumetric interpolated breath-hold examination (VIBE). The image-intensity differences were computed after image registration as measures of tissue-density changes, which are compared with hyperpolarized ³He images. Our results indicate proton MRI is promising at detecting significant ventilation defects in the lung.

Simon Triphan¹, Felix Breuer¹, and Peter Jakob^1,2
1Research Centre Magnetic Resonance Bavaria e.V., Würzburg, Germany, ²Experimental Physics 5, University Würzburg, Würzburg, Germany

The behaviour of lung T₂* under wash-in and wash-out of pure oxygen was measured using a 2D UTE sequence. A time-curve of T₂* was produced using golden angle radial sampling and a sliding window technique. By also calculating T₂* by navigation using the DC-signal acquired in each trajectory, T₂* effects of breathing and oxygen concentration can be separated, increasing the visibility of wash-in and -out. Producing T₂* maps for different breathing states using navigation in a single experiment also allows reconstruction of maps for identical breathing states which can be subtracted to give T₂* difference maps depending of oxygen concentration.

Stefan Weick¹, Felix A. Breuer², Martin Blaimer², Michael Flentje³, Christian Fink⁴, Lothar R. Schad⁵, and Peter M Jakob^1,2
1Department of Experimental Physics 5, University of Wuerzburg, Wuerzburg, Bavaria, Germany, ²Research Center Magnetic Resonance Bavaria e.V (MRB), ³Department of Radiation Oncology, University Hospital Wuerzburg, ⁴Department of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, ⁵Department of Computer Assisted Clinical Medicine, University Medical Center Mannheim

In this work, time resolved three dimensional (4D) human lung imaging in high spatial resolution is performed on volunteers as well as patients under free breathing conditions. To this end, the DC signal was acquired every TR and used for gating thereby allowing for the retrospective reconstruction of different respiratory phases. Additionally, a quasi random sampling strategy was employed leading to an increased stability of parallel imaging reconstruction in the case of missing data points due to gating. 4D lung imaging can be used for the assessment of respiratory mechanics and tumor displacement for an individual motion adapted radiotherapy planning.

Daniel Stäb¹, André Fischer¹, Christian Oliver Ritter¹, Dietbert Hahn¹, and Herbert Köstler^1
1Institute of Radiology, University of Würzburg, Würzburg, Germany

Pulmonary MRI is well-known to be susceptible to artifacts resulting from cardiac and respiratory motion or flow. In addition however, truncation artifacts or Gibbs ringing introduced at the boundaries between lung and surrounding body tissue are present, especially when imaging with low spatial resolution. In this work, the effects of these Gibbs artifacts on the reconstructed images as well as on quantitative lung parameters like T₁ or pulmonary perfusion are demonstrated.

Jeffrey S Nackos¹, Kevin M Johnson^1,2, Mark L Schiebler¹, Christopher J Francois¹, Sean B Fain^1,2, Maria D Cornejo², Shane A Wells¹, and Scott K Nagle^1,2
1Radiology, University of Wisconsin, Madison, Wisconsin, United States, ²Medical Physics, University of Wisconsin, Madison, Wisconsin, United States

Evaluation of the lungs using MRI has traditionally been limited by signal loss due to very short T2* and low proton density. Ultrashort echo time (UTE) SPGR imaging can be used to overcome these limitations and has shown promise in recent animal studies. We demonstrate the feasibility of using a respiratory gated 3D radial UTE method on commercially available hardware to evaluate lung structures in healthy human subjects.

Yoshiharu Ohno^1,2, Mizuho Nishio¹, Hisanobu Koyama^1,2, Masaya Takahashi³, Takeshi Yoshikawa¹, Sumiaki Matsumoto¹, Daisuke Takenaka¹, Katsusuke Kyotani², Nobukazu Aoyama², Hideaki Kawamitsu², Makoto Obara⁴, Marc van Cauteren⁵, and Kazuro Sugimura^1
1Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Radiology, Kobe University Hospital, Kobe, Hyogo, Japan, ³Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, ⁴Philips Electronics Japan, Tokyo, Japan, ⁵Philips Healthcare Asia Pacific, Tokyo, Japan

CT is most widely used for radiological assessment of disease severity in CTDs. Recently, we have tried to determine the utility of regional T2* measurement in the lung for assessment of pulmonary diseases. We hypothesized that T2* measurement in the lung at 3 T MR system has a potential role to play as a method for assessment of pulmonary functional loss and disease severity in CTD patients. The purpose of this study was to determine the capability of pulmonary MRI with ultra-short TEs (UTEs) in a 3 T system for pulmonary functional and disease severity assessments in patients with CTD.

Rexford D Newbould¹, Rishi Gupta², Anura Malaweera², Andrew Lewis², Kishan R Parmar², and Lea Sarov-Blat^3
1Imanova Ltd, London, United Kingdom, ²Imperial College London, London, United Kingdom, ³GlaxoSmithKline, Discovery Medicine-Heart Failure DPU

Congestive heart failure (CHF) is characterised by an elevated left ventricular end diastolic pressure leading to an increased pressure in pulmonary vasculature, causing fluid to leak into the interstitial spaces of the lung tissue. Continuous HASTE imaging of the right lung was performed in 12 healthy controls (HCs) and 12 subjects with CHF who underwent passive leg raising (PLR). PLR consisted of raising the subject’s legs to a 45° angle while lying in the scanner bore. HASTE acquisitions could map gravity-dependent lung density as well as the response to PLR, although a non-significant difference in lung density response was found between HCs and early-stage CHFs.

Yogesh K Mariappan¹, Bryan L Striemer¹, David L Levin¹, Robert Vassallo², Richard L Ehman¹, and Kiaran P McGee^1
1Radiology, Mayo Clinic, Rochester, MN, United States, ²Pulmonary and critical care medicine, Mayo Clinic, Rochester, MN, United States

Our overall goal is to develop magnetic resonance elastography (MRE) for the in vivo assessment of human lung. We have recently demonstrated that lung shear stiffness can be spatially resolved in vivo using a ¹H pulmonary MRE pulse sequence. The objective of this work was to validate this technique by measuring lung stiffness changes at four different states of respiration including residual volume (RV), total lung capacity (TLC) and two intermediate states in 5 healthy volunteers. In all volunteers shear stiffness increased from RV to TLC and correlated with volume dependent changes in lung stiffness.

Yogesh K Mariappan¹, Kevin J Glaser¹, Rolf D Hubmayr², Richard L Ehman¹, and Kiaran P McGee^1
1Radiology, Mayo Clinic, Rochester, MN, United States, ²Pulmonary and critical care medicine, Mayo Clinic, Rochester, MN, United States

We have recently demonstrated that the shear stiffness of human lung parenchyma can be spatially resolved in vivo using spin echo breath-held MR Elastography (MRE) techniques. A disadvantage of this approach is relatively long breath-hold times limiting clinical translation particularly in patients with compromised respiratory function. To address this limitation a respiratory triggered EPI-based MRE sequence has been developed and tested. In vivo data in normal volunteers has demonstrated that changes in lung stiffness throughout the respiratory cycle can be quantified without the need for breath-held acquisitions while still maintaining phase-contrast signal-to-noise ratio compared to breath-held spin echo acquisitions.

Kiaran P. McGee¹, Rolf D. Hubmayr², Yogesh K Mariappan¹, Zhonghao Bao³, David L. Levin¹, Rickey E. Carter⁴, and Richard L Ehman^1
1Radiology, Mayo Clinic & Foundation, Rochester, Mn, United States, ²Pulmonary and Critical Care Medicine, Mayo Clinic & Foundation, Rochester, Mn, United States, ³Information Technology, Mayo Clinic, Rochester, Mn, United States, ⁴Health Sciences Research, Mayo Clinic, Rochester, Mn, United States

Pulmonary surfactant is lipoprotein complex responsible for decreasing surface tension at the alveolar air-fluid interface, is a known moderator of lung elastic recoil and a major contributor to lung stiffness. While surfactant can be assayed by bronchiolar lavage its spatial distribution and effects on lung stiffness cannot be directly quantified. We present first data demonstrating that magnetic resonance elastography (MRE) can quantify both global and regional changes in lung elastic recoil caused by loss of surfactant in a flooded lung. Regional increases in MRE-based lung stiffness with inflation pressure suggest that MRE can also predict areas of active recruitment.

Andrea Bianchi¹, Gerard Raffard², Olga Ousova¹, Annaïg Ozier¹, and Yannick Crémillieux^1
1Centre de Recherche Cardio-Thoracique de Bordeaux, Université Bordeaux Segalen, Bordeaux, France, ²Centre de Résonance Magnétique des Systèmes Biologiques, Université Bordeaux Segalen, Bordeaux, France

In this study we present the MRI investigation of a realistic model of asthma in mice (ovalbumin sensitization without aluminum hydroxide), mimicking the first steps in the development of the disease in humans. The small peribronchovascular inflammation, almost three times less than in the models with alum, was visualized and quantified thanks to the improvements over the typical lung images allowed by the use of an Ultra-Short Echo Time (UTE) sequence; the inflammation was also correlated with the enhanced pause of the mice measured with a plethysmograph, an important means of quantification of airways hyperresponsiveness in mice.

Liya Wang^1,2, Xiaodong Zhong³, Xianghong Peng⁴, Jing Huang^1,2, Xiaofeng Yang⁵, and Hui Mao^1,2
1Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia, United States, ²Center for Systems Imaging, Emory University School of Medicine, Atlanta, Georgia, United States, ³MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, ⁴Emory Winship Cancer Institute, Emory University, Atlanta, Georgia, United States, ⁵Radiation Oncology, Emory University School of Medicine, Atlanta, Georgia, United States

This study investigated the feasibility of gadolinium contrast agent enhanced UTE MRI of lung in mice on a standard 3 Tesla clinical MRI system with the goal to improve the image quality of pulmonary MRI. The results demonstrated that the administering gadolinium contrast agent combining with UTE acquisitions provide the high sensitivity and image contrast in MRI of lung. The gadolinium contrast enhanced UTE MRI of lung is dose-dependent and can be optimized.

Daniel Alamidi¹, Penny L Hubbard^2,3, Deirdre M McGrath⁴, Jelena Pesic⁵, Magdalena Zurek⁵, Malin J Gustavsson⁵, Charlott Brunmark⁶, Josephine Naish^2,3, Lars E Olsson^1,5, and Geoff J Parker^2,3
1Department of Radiation Physics, The University of Gothenburg, Gothenburg, Sweden, ²Imaging Sciences and Biomedical Engineering, The University of Manchester, Manchester, United Kingdom, ³The Biomedical Imaging Institute, The University of Manchester, Manchester, United Kingdom, ⁴Radiation Medicine Program, Princess Margaret Hospital, Toronto, Canada, ⁵AstraZeneca R&D, Mölndal, Sweden, ⁶Truly Translational Sweden, Lund, Sweden

In this study MR imaging was used to study the effects of tobacco smoke on lungs. Experiments were performed on both human smokers and mice exposed to tobacco smoke. T1 changes in the lungs were found in both human smokers and tobacco smoke exposed mice. A translational link between humans and animals exposed to tobacco smoke expressed as decreased T1 has been demonstrated. Using MRI tobacco exposed animals may be a translational animal model of COPD.

Magdalena Zurek¹, Daniel Alamidi¹, Edvin Johansson¹, Frank Risse¹, and Lars E Olsson^1
1Personalised Healthcare and Biomarkers, Imaging, AstraZeneca R&D, Mölndal, Sweden

A robust method for accurate assessment of T1 in rodent lungs was implemented. The sequence (segmented 2D-IR with ultrashort echo-time (UTE) and radial k-space sampling) was validated via simulations, and sequence parameters were optimized in a phantom study. The presented technique enables the T1 of pulmonary structures to be mapped with a high spatial resolution. The protocol has the potential to assess lung properties relevant in various animal models of pulmonary disorders.

Amir Moussavi^1,2, Martin Uecker^1,3, Tilman Johannes Sumpf¹, Roland Tammer^1,2, Jens Frahm¹, and Susann Boretius^1,4
1Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut fuer biophysikalische Chemie, Goettingen, Germany, ²DFG Research Center for Molecular Biology of the Brain (CMPB), Goettingen, Germany, ³Electrical Engineering and Computer Science, University of California, Berkeley, United States, ⁴Klinik für Diagnostische Radiologie, Universitätsklinikum Schleswig-Holstein, Kiel, Germany

To avoid the necessity of cardiorespiratory gating, lung MRI of the mouse requires short acquisition times. The combination of highly under-sampled radial FLASH with a nonlinear inverse image reconstruction algorithm allowed for a temporal resolution of 100 ms per image of the mouse lung at a sufficient spatial resolution. Moreover, the lung parenchymal motion and the up and down movement of the thoracic diaphragm were clearly visible while breathing, offering the possibility to monitor breathing irregularities or fast, single-events such as rapid short-term responses to medications.

Greetje Vande Velde¹, Tom Dresselaers¹, Eric Verbeken², Katrien Lagrou³, and Uwe Himmelreich^1
1Biomedical NMR unit/ MoSAIC, KU Leuven, Leuven, Flanders, Belgium, ²Morphology and Molecular Pathology, UZ Leuven, Leuven, Flanders, Belgium,³Experimental Laboratory Medicine, UZ Leuven, Leuven, Flanders, Belgium

Cryptococcus is an encapsulated yeast that causes life-threatening disease. Cryptococcosis mostly affects the lung of a host and may spread to the brain, but this pathogenesis is still largely enigmatic. For the first time we were able to visualize onset and progression of pneumonial cryptococcosis with IntraGate MRI, long before symptomatic disease ocurred. Being able to dynamically follow-up disease progression will greatly enhance cryptococcosis research, as MRI can identify the relevant time frame for molecular and histological analysis of BBB crossing of cryptococs with very good time resolution.

Taeho Kim¹, Michael Graf², Elaine Ryan³, and Paul Keall^1
1Radiation Physics Laboratory, Unviersity of Sydney, Camperdown, NSW, Australia, ²GE Healthcare, ³Unviersity of Sydney

40% of lung cancer patients receive radiotherapy as part of their treatment. Involuntary respiratory motion can compromise treatment quality by decreasing image quality and lowering tumor control (4-5% dose variation per 5 mm tumor excursion). The aim of this study is to develop a novel respiratory motion control system using audiovisual (AV) biofeedback combined with chest MRI to improve diaphragm motion reproducibility, increasing respiratory gating efficiency and reducing motion artifacts in MRI.

Katsusuke Kyotani¹, Yoshiharu Ohno^1,2, Nobukazu Aoyama¹, Hideaki Kawamitsu¹, Takeshi Yoshikawa², Satoru Takahashi², Hisanobu Koyama², Mizuho Nishio², Sumiaki Matsumoto², Saori Satou³, and Kazuro Sugimura^2
1Radiology, Kobe University Hospital, Kobe, Hyogo, Japan, ²Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ³Toshiba Medical Systems, Ohtawara, Tochigi, Japan

Multi-transmit (i.e. 2-channel 2-port) and multi-phase transmission (i.e. 2-channel 4-port) techniques may be one of the solutions for improving image quality and capability of 3T MR system not only chest MR imaging, but also other body MR imaging. We hypothesized that multi-phase transmission RF system could improve B1 inhomogeneity and image quality on basic and clinical studies as compared with single-transmit and multi-transmit RF systems. The purpose of this study was to directly and prospectively compare B1 homogeneity and image quality of chest MR imaging among three different RF systems on 3T MR system.

André Fischer¹, Christian Oliver Ritter¹, Dietbert Hahn¹, and Herbert Köstler^1
1Institute of Radiology, University of Wuerzburg, Wuerzburg, Germany

This work describes the ability of Fuzzy C-Means (FCM) clustering to accurately distinguish between pulmonary parenchyma, pulmonary vessels, the heart, and the surrounding tissue in dynamic contrast enhanced (DCE)-MRI. FCM clustering achieves this by clustering voxels with similar temporal signal courses together. A 3D DCE-MRI dataset was accordingly segmented and is presented in this work. This technique enables user independent automatic segmentation of the lung parenchyma necessary to quantify lung perfusion. Thereby, a subjective bias in data analysis as often present in manual parenchyma segmentation is lowered.

Elaine Hegarty^1,2, Alexei V Ouriadov¹, Matthew S. Fox^1,2, Eugene Wong^2,3, Ian D. Welch⁴, and Giles E. Santyr^1,3
1Imaging Research Laboratories, John P. Robarts Research Institute, London, Ontario, Canada, ²Physics and Astronomy, University of Western Ontario, London, Ontario, Canada, ³Medical Biophysics, University of Western Ontario, London, Ontario, Canada, ⁴Animal Care and Veterinary Services, University of Western Ontario, London, Ontario, Canada

Magnetic Resonance (MR) imaging of hyperpolarized noble gases (3He and 129Xe) provides anatomical and functional information about the lungs. Apparent diffusion coefficient (ADC) in the lung is anisotropic and can be described by two components; (i) a longitudinal coefficient (DL) representing diffusion along the terminal bronchiole and (ii) a transverse coefficient (DT) representing diffusion perpendicular to the terminal airway. 129Xe ADC anisotropy was mapped in the lungs of a cohort of rats receiving irradiation and compared to histology. Radiation induced lung injury (RILI) was observed in ADC maps as well as histology.

Kiarash Emami¹, Yinan Xu¹, Hooman Hamedani¹, Harrilla Profka¹, Yi Xin¹, Puttisarn Mongkolwisetwara¹, Stephen J. Kadlecek¹, Masaru Ishii², and Rahim R. Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Otolaryngology - Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States

Accelerated imaging of fractional ventilation by parallel imaging effectively reduces the total imaging time and the overall RF-induced signal decay. This in turn improves the accuracy of fractional ventilation measurements, while allowing for a more similar respiratory pattern during HP gas MRI to that of normal breathing. Given the multitude of parameters that define an accelerated imaging protocol (e.g. flip angle and acceleration factor), an objective analysis of these effects can assist in selecting an optimal set of parameters to minimize estimation error while maintaining study requirements.

Kiarash Emami¹, Yi Xin¹, Puttisarn Mongkolwisetwara¹, Harrilla Profka¹, Jennia Rajaei¹, Stephen J. Kadlecek¹, Masaru Ishii², and Rahim R. Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Otolaryngology - Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States

Introduction of controlled pre-acquisition time delay in the existing fractional ventilation imaging technique provides a tool for determining regional gas arrival time constant, with a fairly similar implication to lung RC time constants on a regional basis. Results can alternatively be utilized to select a proper pre-acquisition time delay to minimize motion-induced errors and well mixing of inspired and residual gases in standard specific ventilation imaging applications with HP gas MRI.

Maurizio Cereda¹, Yi Xin², Kiarash Emami², Stephen J. Kadlecek², Puttisarn Mongkolwisetwara², Harrilla Profka², Stephen Pickup², Clifford S. Deutschman¹, and Rahim R. Rizi^2
1Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, United States, ²Radiology, University of Pennsylvania, Philadelphia, PA, United States

Surfactant depletion causes atelectasis and predisposes subjects to ventilator associated lung injury due to harmful pulmonary airspace dilatation, as detected by increased 3He apparent diffusion coefficient (ADC). Utilizing positive end expiratory pressure and surfactant administration as alveolar recruitment techniques could protect the lungs from injury. The presented result in rats shows that the combination of these two techniques synergistically restores normal airspace size by the effect of reducing ADC value to baseline.

Puttisarn Mongkolwisetwara¹, Milton Rossman², Evguenia Arguiri², Harrilla Profka¹, Kiarash Emami¹, Yi Xin¹, Stephen J. Kadlecek¹, Melpo Christofidou-Solomidou², and Rahim R. Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Medicine, University of Pennsylvania, Philadelphia, PA, United States

Idiopathic Pulmonary Fibrosis (IPF) is a fatal lung disease. It causes scarring of the lungs and limits oxygen transport across membranes into bloodstream. The disease course of IPF is variable. In this work, hyperpolarized (HP) 3He MRI is used to acquire regional information of oxygen tension, oxygen uptake and fractional ventilation in a rat model of interstitial fibrosis secondary to bleomycin. Significant correlation between oxygen uptake and biological markers of inflammation and fibrosis in lung suggests that the oxygen-weighted HP MRI can be used as a tool for early detection of fibrosis development and evaluate disease progress in humans.

Yi Xin¹, Kiarash Emami¹, Puttisarn Mongkolwisetwara¹, Harrilla Profka¹, Garrett Greenan², Stephen J. Kadlecek¹, Stephen Pickup¹, Brian J. Bolognese³, Edward R. Long III³, Joseph P. Foley³, Patricia L. Podolin³, Masaru Ishii⁴, and Rahim R. Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²University of Pennsylvania, Philadelphia, PA, United States, ³Respiratory Therapeutic Area, GlaxoSmithKline, King of Prussia, PA, United States, ⁴Otolaryngology - Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States

Changes in pulmonary microstructure are examined in mice chronically exposed to cigarette smoke using HP 3He diffusion MRI.The smoked mice show significantly larger 3He ADC values both at high and low pulmonary pressure levels reflecting enlarged size of alveolar and small airways, as well as a higher growth rate of ADC as a function of pressure illustrating larger compliance. These results are supported by histology. We conclude that 3He ADC can serve as a useful biomarker to elucidate underlying remodeling of lung tissue resulting from smoking.

Xiaojun Xu¹, Graham Norquay¹, Helen Marshall¹, Juan Parra-Robles¹, and Jim M. Wild^1
1Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

T₂^* of hyperpolarised ¹²⁹Xe is largely affected by the magnetic susceptibility at the tissue/air interfaces within the lungs. Initial results at forced residual volume (FRV) + 1 l are reproducible, yet shorter than the only other previously reported values in the conference literature. Repeated measurements with the lungs filled up with room air to total lung capacity (TLC) instead of FRV + 1 l coincide with previous results of T₂^* values, indicating a significant dependence of the transverse relaxation constant T₂^* on lung inflation volume.

Alexei V Ouriadov¹, Adam Farag¹, Miranda Kirby^1,2, David G McCormack³, Grace Parraga^1,4, and Giles E Santyr^1,2
1Imaging Research Laboratories, Robarts Research Institute, The University of Western Ontario, London, Ontario, Canada, London, Ontario, Canada,²Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada, London, Ontario, Canada, ³Division of Respirology, Department of Medicine, The University of Western Ontario, London, Ontario, Canada, London, Ontario, Canada, ⁴Department of Medical Imaging, The University of Western Ontario, London, Ontario, Canada, London, Ontario, Canada

The availability of large volumes (up to 2 L) of highly polarized 129Xe gas provides a way to conduct multiple b value measurements of the 129Xe ADC in human subjects for the quantitative evaluation of lung tissue microstructure. In contrast with the single exponential ADC method, xenon diffusion anisotropy may be studied with a multiple b value approach, yielding transverse and longitudinal diffusion coefficients. In this pilot study, we explore the potential of 129Xe MRI for the evaluation of diffusion anisotropy changes in a small group of COPD subjects compared to healthy volunteers.

Xiaojun Xu¹, Graham Norquay¹, Steven R. Parnell¹, Martin H Deppe¹, Salma Ajraoui¹, Ralph Hashoian², Helen Marshall¹, Paul Griffiths¹, Juan Parra-Robles¹, and Jim M. Wild^1
1Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom, ²Clinical MR Solutions, United States

In this study, the SNR of hyperpolarised ¹²⁹Xe human lung MRI was compared at 1.5 T and 3 T. Experiments were performed at both B₀ fields with quadrature double Helmholtz transmit-receive chest coils of the same geometry. Differences in sensitivity between the two RF receiver systems and body coils that are due to factors not directly related to field strength were assessed and normalised by using a thermally-polarised ¹²⁹Xe phantom. There were no significant differences observed in image SNR of ¹²⁹Xe ventilation lung images obtained at the two field strengths.

Guilhem Collier¹, Tadeusz Palasz¹, Bartosz Glowacz¹, Anna Wojna¹, Zbigniew Olejniczak², Mateusz Suchanek³, and Tomasz Dohnalik^1
1Jagiellonian University, Krakow, Malopolska, Poland, ²Polish Academy of Sciences, Krakow, Malopolska, Poland, ³Agricultural University of Cracow, Krakow, Malopolska, Poland

Imaging of air spaces in the lungs with magnetic resonance became possible thanks to the use of hyperpolarized noble gases such as helium-3. MEOP process has been studied by our group for several years in non-standard conditions (magnetic field > 0.5T and pressures > 10mbar) in order to increase its efficiency. Following the promising results obtained during these systematic studies (the production rate being improved by an order of magnitude compared to the best results obtained in standard conditions), a prototype of high field polarizer working inside a medical scanner at 1.5T was designed and successfully used for human lung MRI.

Eric Frederick^1,2, Iga Muradian³, Natalia Lisitza³, Mike Dabaghyan², Mirko Hrovat⁴, and Samuel Patz^3
1Brigham and Women's Hospital, Melrose, MA, United States, ²Mirtech Inc., ³Brigham and Women's Hospital, ⁴Mirtech, United States

We determined the optimal parameters for SB-XTC using both Monte Carlo simulations as well as the analytic solution. These results were directly compared with our experimental data and we observed an offset that is comparable to what is expected from physiological variations. Unlike previous reports, we considered the effect of the phase encoding pulses and determined that uncertainty in the measured values can be reduced by 82.3% if the in-plane resolution is halved.

Hooman Hamedani¹, Masaru Ishii², Kiarash Emami¹, Stephen J. Kadlecek¹, Yi Xin¹, Puttisarn Mongkolwisetwara¹, Nicholas N. Kuzma¹, Biao Han¹, Harrison McAdams³, G. Wilson Miller⁴, Milton Rossman⁵, and Rahim R. Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Otolaryngology - Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States, ³Biological Basis of Behavior Program, University of Pennsylvania, Philadelphia, PA, United States, ⁴Radiology, University of Virginia, Charlottesville, VA, United States, ⁵Medicine, University of Pennsylvania, Philadelphia, PA, United States

Four healthy non-smokers and four asymptomatic smokers underwent three repetitions of hyperpolarized 3He MRI imaging in a two-week period to obtain a measure of intraclass test-retest repeatability for an oxygen-weighted 3He MRI scheme to measure the regional alveolar partial pressure of oxygen. 12 slices were imaged during a 12-second breath-hold with a reasonable spatial resolution. Inter and intraclass repeatability was measured for both global and regional distributions of partial pressure of oxygen in subjects. A mixed-effect model with random effects was regressed to 3x3x3 cm3 voxels of all human subjects to estimate a correlation coefficient for each group.

Juan Parra-Robles¹, Martin H Deppe¹, Xiaojun Xu¹, Helen Marshall¹, and Jim M Wild^1
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom

In this work, the effect of diffusion time on 3He ADC is investigated through experiments with healthy human volunteers. The results of this work show that the short-range ADC of 3He gas in human lungs decreases with increasing diffusion time, while its degree of non-monoexponentiality remained constant in the range 1.4-2.5 ms. The results demonstrate that the cylinder model produces inaccurate estimates of the airway dimensions as a consequence of incompletely accounting for the diffusion-time dependence in the model equations.

Hooman Hamedani¹, Kiarash Emami¹, Stephen J. Kadlecek¹, Yi Xin¹, Puttisarn Mongkolwisetwara¹, Biao Han¹, Harrison McAdams², Masaru Ishii³, G. Wilson Miller⁴, Milton Rossman⁵, and Rahim R. Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Biological Basis of Behavior Program, University of Pennsylvania, Philadelphia, PA, United States, ³Otolaryngology - Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States, ⁴Radiology, University of Virginia, Charlottesville, VA, United States, ⁵Medicine, University of Pennsylvania, Philadelphia, PA, United States

Ten healthy non-smokers and twenty asymptomatic smokers participated in a hyperpolarized 3He ADC and pAO2 MRI imaging. 12 slices with thickness of 13mm were acquired for each subject during 12-second breath-hold with a reasonable spatial resolution. Before each MRI session, a pulmonary function test was performed. Imaged ADC and pAO2 distributions of whole-lung were regressed on PFT results and ANNOVA test was performed to study the power of discriminatory of MRI metrics in distinguishing the smokers from nonsmokers.

Stephen J. Kadlecek¹, Yinan Xu¹, Kiarash Emami¹, Yi Xin¹, Puttisarn Mongkolwisetwara¹, Hooman Hamedani¹, Harrison McAdams², Masaru Ishii³, and Rahim R. Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Biological Basis of Behavior Program, University of Pennsylvania, Philadelphia, PA, United States, ³Otolaryngology - Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States

An improved method to image PAO2 maps in human lungs is proposed using parallel accelerated HP 3He MRI. Using computational models and phantoms it is shown that when used effectively, accelerated undersampled imaging can lead to a more accurate measure of oxygen tension in the lungs. Technique feasibility and advantage is demonstrated in a healthy human subject. The improvement in PAO2 accuracy is linked to the more efficient use of the finite polarization of HP gas and by increased weighting of the O2-induced contrast versus RF-induced signal decay. Potential confounding factors, e.g., image artifacts or blurring due to accelerated reconstruction, are not observed in this study.

Chengbo Wang¹, John P Mugler, III^1,2, Eduard E de Lange¹, and Talissa A Altes^1
1Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States, ²Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States

Short-time-scale(STS) and long-time-scale(LTS) helium-3 diffusion were measured in 21 controls, 28 secondhand-smokers and 19 smokers. The STS and LTS ADC values of smokers were significantly elevated compared to controls and secondhand-smokers (P < 0.001 both). One-Way ANOVA analysis indicated that the mean STS ADC values from secondhand-smokers was significantly elevated compared with that of controls (increase for 10.2%, P=0.007) while not for the LTS ADC (increase 13.2%, P=0.238).

Kiarash Emami¹, Hooman Hamedani¹, Biao Han¹, Yinan Xu¹, Stephen J. Kadlecek¹, Masaru Ishii², and Rahim R. Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Otolaryngology - Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States

The feasibility of performing multi-breath fractional ventilation hyperpolarized gas MRI in human subjects are demonstrated. This methodology is the first to report a quantitative measure of respiratory gas distribution and replacement in human lungs. The detailed mechanisms of gas transport in lungs with heterogeneous ventilation defects require further investigation to explain the reflections on fractional ventilation values before proper interpretation can be made. Nevertheless fractional ventilation can now be evaluated as a quantitative regional marker to investigate heterogeneous obstructive lung diseases.

Peter Komlosi¹, Talissa A. Altes¹, Karen E. Mooney², G. Wilson Miller¹, Jaime F. Mata¹, Eduard E. de Lange¹, William A. Tobias², Gordon D. Cates Jr.², and John Mugler III^1
1Department of Radiology, University of Virginia, Charlottesville, VA, United States, ²Department of Physics, University of Virginia, Charlottesville, VA, United States

The goal of the present study was to evaluate the field-strength dependence of He3 ADC values at 0.4T and 1.5T. We found that for each of three orthogonal diffusion-sensitization directions, ADC values for the healthy human lung based on 2 b-value measurements were typically a few percent smaller at 0.43T than at 1.5T, and that these differences were statistically significant.

Hirohiko Imai¹, Hironobu Matsumoto¹, Yurika Miyakoshi¹, Daichi Takemori¹, Shinya Nakasone¹, Susumu Yamamoto¹, Hideaki Fujiwara¹, and Atsuomi Kimura^1
1Department of Medical Physics and Engineering, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan

We investigated the feasibility of quantitative assessment of pulmonary functions with hyperpolarized (HP) ¹²⁹Xe MRI in spontaneously breathing mice. Pulmonary ventilation and gas exchange were regionally evaluated in a mouse model of chronic obstructive pulmonary disease (COPD) induced by multiple administration of cigarette smoke solution (CSS) combined with lipopolysaccharide (LPS). Significant dysfunctions of ventilation and gas exchange in CSS+LPS-treated mice were observed. Thus, it was shown that this methodology is sensitive to differences in these pulmonary functions between the newly developed COPD models and controls.

Helen Marshall¹, Xiaojun Xu¹, Graham Norquay¹, Steve R Parnell¹, Juan Parra-Robles¹, and Jim M Wild^1
1Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

Dynamic radial ³He imaging allows rapid imaging of gas flow and can give information about lung motion and gas trapping. ¹²⁹Xe and ³He dynamic radial imaging of an inhalation and exhalation manoeuvre were compared in a healthy volunteer. Comparable lung movement and gas filling was seen, despite the lower signal to noise ratio of the ¹²⁹Xe images. Region of interest signal time-courses showed a faster rate of signal increase during inhalation for ³He than¹²⁹Xe, which may be due to the greater density of ¹²⁹Xe. The rate of signal decay during exhalation was similar for both gases.

Marcus John Couch¹, Brian O'Sullivan², John Roche^1,3, Ronn Walvick^3,4, Shaokuan Zheng³, Dawn Baker², Mac Johnson⁵, Martyn Botfield⁵, and Mitchell Albert^1,6
1Thunder Bay Regional Research Institute, Thunder Bay, Ontario, Canada, ²Department of Pediatrics, University of Massachusetts Medical School, MA, United States, ³Department of Radiology, University of Massachusetts Medical School, MA, United States, ⁴Center for Biomedical Imaging, New York University Langone Medical Center, NY, United States, ⁵Vertex Pharmaceuticals Incorporated, MA, United States, ⁶Department of Chemistry, Lakehead University, Thunder Bay, Ontario, Canada

Hyperpolarized gas MRI provides high-resolution regional information on lung function, offering promise as a valuable outcome measure for cystic fibrosis (CF) and other pulmonary diseases. Using advanced quantitative analyses, we examined repeatability of ³He MR images of five CF patients over several weeks. A pulmonologist read the images, and ventilation volume was determined using an advanced semiautomatic segmentation algorithm. Total ventilation volume was statistically consistent over time. A pixel-by-pixel analysis, however, did show statistical differences. Our results indicate that investigators will need to evaluate the level of sensitivity to use when applying this technology to disease staging and therapy evaluation.

Chengbo Wang¹, John P Mugler, III¹, Eduard E de Lange¹, and Talissa A Altes^1
1Radiology and Medical Imaging, University of Virginia, Charlottesville, Virginia, United States

Global ADC values and regional ADC maps of hyperpolarized helium-3 in human lungs were measured at the long-time-scale in 19 healthy subjects and 19 smokers. For smokers, global ADC increased 107% (P<0.01) while mean of regional ADC maps increased 93% (P<0.01) compared with those of the controls. And global ADC strongly correlated with mean of regional ADC maps (r=0.96,P<0.001), suggesting global ADC may be a useful substitute for mean of regional ADC maps to investigate lung disease to save expensive 3He.

Kun Qing¹, Talissa A. Altes², Nicholas J. Tustison², Jaime F. Mata², G. Wilson Miller², Eduard E. de Lange², William A. Tobias³, Gordon D. Cates³, James R. Brookeman², and John P. Mugler^2
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ²Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States, ³Physics, University of Virginia, Charlottesville, VA, United States

The purpose of this work was to directly and quantitatively evaluate the reconstruction fidelity of undersampled compressed-sensing (CS) reconstructed 3D image sets by acquiring both the fully-sampled and undersampled acquisitions for a given nucleus (He-3 or H-1) in the same breath hold. Undersampled, CS-reconstructed H-1 3D images showed high similarity to their fully-sampled counterparts. While somewhat lower similarity indices were found for undersampled, CS-reconstructed He-3 3D image sets, this can be attributed to factors unrelated to the actual performance of the undersampled acquisition with CS reconstruction, including diaphragm movement, the non-equilibrium hyperpolarized magnetization, and B1 inhomogeneity.

Sarah Svenningsen^1,2, Andrew Wheatley¹, Miranda Kirby^1,2, Adam Farag¹, Alexei Ouriadov¹, Giles Santyr^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, ³Department of Medicine, The University of Western Ontario, London, Ontario, Canada

The high cost and limited availability of helium-3 (3He) gas has restricted clinical translation of this structure-function pulmonary imaging method, necessitating a transition to xenon-129 (129Xe) gas for pulmonary imaging which provides distinct differences that must be explored. We compared 3He and 129Xe ADC anatomical differences from the anterior-to-posterior slices in five subjects with asthma. For 3He and 129Xe, the relationship between anatomical location and ADC was statistically significant. Although 129Xe atoms are heavier, have slower diffusion coefficients in air with the potential for less homogeneous mixing, anatomical ADC gradients are similar to 3He MRI which bodes well for translation.

Shimon Aronhime¹, Claudia Calcagno¹, Hadrien Arezki Dyvorne¹, Philip Robson¹, Henry Rusinek², Maria Isabel Fiel³, Douglas Dieterich³, and Bachir Taouli^1
1Radiology, Mount Sinai School of Medicine, New York, New York, United States, ²Radiology, New York University, New York, New York, United States,³Department of Medicine/Liver Disease, Mount Sinai School of Medicine, New York, New York, United States

Perfusion changes observed in liver fibrosis and cirrhosis can be quantified with perfusion-weighted MRI and a pharmacokinetic model. In this preliminary study, we have assessed the reproducibility of liver perfusion metrics using techniques aimed at optimizing the conversion of signal intensity to gadolinium concentration during 3D T1 perfusion—weighted MRI of the liver. All conversion techniques proved to have acceptable to poor reproducibility with no significant difference in reproducibility between the different conversion techniques. These early results indicate that reproducibility of liver perfusion parameters is not affected by the method of gadolinium concentration calculation.

Mahdi S Rahimi¹, Kang Wang², James H Holmes², Jean H Brittain², Scott B Reeder^1,3, and Frank R Korosec^3,4
1Biomedical Engineering, University of Wisconsin, Madison, WI, United States, ²Global Applied Science Laboratory, GE Healthcare, Madison, WI, United States, ³Radiology, University of Wisconsin, Madison, WI, United States, ⁴Medical Physics, University of Wisconsin, Madison, WI, United States

Dynamic Contrast Enhanced (DCE) liver perfusion imaging is a powerful tool for detection and assessment of liver lesions, including hepatocellular carcinoma (HCC). In this work, The IVD-HYCR method is improved by using fluoro-triggering and enabling continuous scanning during the passage of the contrast agent with retrospective identification of multiple breath-hold start times and durations, increasing the method’s ability to accurately and consistently acquire high frame-rate images with optimal contrast timing. Continuous scanning during multiple breath-holds and use of data sharing enables acquisition of high spatial and temporal resolution images and numerous time frames, permitting more complete assessment of contrast dynamics.

MUKTA Dilipkumar AGRAWAL¹, Pascal Spincemaille¹, Kevin W Mennitt¹, Bo Xu², Yi Wang^1,2, and Martin R Prince^1,3
1Radiology, Weill Cornell Medical Center, New York, NY, United States, ²Departments of Biomedical Engineering, Cornell University, New York, NY, United States, ³Radiology, Columbia University, New York, NY, United States

Purpose: To assess 3 second temporal resolution for arterial phase bolus timing on dynamic liver MRI. Methods: : 100 consecutive patients undergoing fluoro-triggered dynamic gadoxetate enhanced liver MRI with standard LAVA Cartesian k-space acquisition, were compared to 61 consecutive patients imaged using a spiral k-space trajectory LAVA reconstructed at 3second temporal resolution with sliding window reconstruction. Results: Spiral LAVA had superior bolus timing, hepatic artery branch order visualization and overall image quality scoring, compared to standard LAVA (p< 0.001). Conclusion: Dynamic liver MRI bolus timing improves using 3second temporal resolution.

Aaron Burns¹, Ersin Bayram², William Simpson¹, and Bachir Taouli^1
1Mount Sinai School of Medicine, New York, NY, United States, ²GE Healthcare, Waukesha, WI, United States

In this study, we have assessed the image quality and liver lesion conspicuity of a quadruple arterial phase acquisition on the liver obtained in a single breath-hold at 3T using a LAVA FLEX sequence with 32 channel torso coil enabling high parallel imaging capabilities. 42 patients were assessed. Image quality was considered to be good to excellent, and none of the patients had non diagnostic quality study. Artifacts were mostly related to parallel imaging ghosting. Hypervascular lesion conspicuity was best during the 2nd arterial phase.

Hersh Chandarana¹, Li Feng¹, Tobias Kai Block¹, Joseph P Stepancic¹, Daniel K Sodickson¹, and Ricardo Otazo^1
1Radiology, NYU Langone Medical Center, New York, NY, United States

Studies have shown the utility of perfusion weighted MR imaging (PWI) in diagnosis of liver fibrosis, characterization of liver lesions, and for monitoring treatment response. However, for PWI to gain acceptance in clinical practice, acquisition schemes need to be robust to respiratory-motion, and should be able to acquire simultaneous high spatial and temporal resolution data with whole-liver coverage. As one approach for accelerated imaging is use of compressed-sensing (CS) reconstruction techniques, we propose the feasibility of performing free-breathing high spatial and temporal resolution imaging of the whole-liver with radial golden-angle sampling with combined compressed sensing and parallel imaging reconstruction.

Krishna Juluru¹, Jonathan P Dyke¹, Pascal Spincemaille¹, Andrew H Talal², and Rhonda Yantiss^3
1Radiology, Weill Cornell Medical College, New York, NY, United States, ²Medicine, Weill Cornell Medical College, New York, NY, United States, ³Pathology, Weill Cornell Medical College, New York, NY, United States

The purpose of this study was to prospectively assess the feasibility of dynamic whole liver imaging using a spiral acquisition technique for the purpose of evaluation of liver fibrosis. The spiral technique allows whole liver imaging with high temporal resolution, while maintaining spatial resolution, and permitting sliding window reconstruction. Enhancement curves demonstrate differences in perfusion between subjects who are normal and who have biopsy-proven liver fibrosis.

Gregory J Wilson^1,2, Anne-Sophie Glantenay³, Holger Eggers⁴, Gwenael Herigault³, Thomas G Perkins¹, John Penatzer¹, and Jeffrey H Maki^2
1Philips Healthcare, Cleveland, OH, United States, ²Radiology, University of Washington, Seattle, WA, United States, ³Philips Healthcare, Best, Netherlands,⁴Philips Research, Hamburg, Germany

Calculated in-phase and opposed-phase images can be produced from dual-echo Dixon imaging with flexible echo times. Potentially, this sequence could replace the standard in-phase and opposed-phase multi-slice FFE scan in a liver exam, shortening exam times. For adequate resolution, however, the 3D dual-echo Dixon scan must be acquired with partial Fourier during a breathhold. Partial Fourier acquisitions complicate Dixon reconstruction as phase information is compromised. This study evaluates a new partial Fourier reconstruction method that is compatible with analytical Dixon water-fat separation.

Hsin-You Ou¹, Susanne Bonekamp¹, David Bonekamp¹, Celia P. Corona-Villalobos¹, Vivek G. Halappa¹, Li Pan², Bernhard Geiger³, and Ihab Kamel^1
1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland, United States, ²Center for Applied Medical Imaging Siemens Corporate Research, Baltimore, Maryland, United States, ³Siemens Corporate Research, Princeton, NJ, United States

Fibrosis and cirrhosis are the consequences of chronic liver disease which are currently assessed by liver biopsy which is limited by its invasiveness, sampling error, and observer variability. Since fibrosis and cirrhosis lead to alterations in blood flow to the liver the evaluation of hemodynamic changes in the liver has been suggested as a noninvasive measure. This study found that the arterial enhancement fraction of the liver on tri-phasic MRI correlated with the degree of liver fibrosis and cirrhosis in 59 patients with chronic liver disease who underwent MRI and liver biopsy within 12 months.

Chansik An¹, Mi-Suk Park¹, Woo-Suk Chung¹, Yeo-Eun Kim¹, Hyung-Jin Rhee¹, and Myeong-Jin Kim^1
1Diagnostic radiology, Yonsei University Health System, Seoul, Korea

Arterial enhancement of a hepatic nodule on dynamic magnetic resonance imaging is one of the major diagnostic criteria for hepatocellular carcinoma. In general, arterial enhancement has been accepted as showing "hyperintensity compared to the surrounding liver parenchyma on arterial phase¡±. In this study, however, we showed that arterial enhancement should be determined by comparing pre-contrast and arterial phase images rather than assessing arterial phase alone, and that subtraction imaging can play a critical role in determining arterial enhancement because it can more accurately demonstrate arterial enhancement than visual comparison of the two phases.

Kang Wang¹, Eric M. Bultman², James H. Holmes¹, Jean H. Brittain¹, and Scott B. Reeder^2,3
1Global Applied Science Laboratory, GE Healthcare, Madison, WI, United States, ²Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, ³Radiology, University of Wisconsin-Madison, Madison, WI, United States

Dynamic contrast-enhanced (DCE) liver MRI is a powerful tool for the diagnosis and characterization of hepatocellular carcinoma (HCC). In this work, a previously developed technique called IVD HYCR is applied to DCE liver imaging to achieve volumetric liver coverage with 2.0 mm isotropic spatial resolution and 4.0 sec temporal resolution. Results from both healthy volunteers and patient volunteers with HCC are presented.

Sharon Elizabeth Clarke¹, Manojkumar Saranathan¹, Dan Rettmann², Brian Hargreaves¹, and Shreyas Vasanawala^1
1Radiology, Stanford University, Stanford, CA, United States, ²GE Healthcare, Global Applied Science Laboratory, Rochester, MN, United States

This study demonstrates that a new method of high temporal-spatial resolution dynamic contrast enhanced liver imaging improves detection of small hepatocellular carcinomas in patients undergoing surveillance for this disease.

Henry Tam¹, Toni Wallace¹, Erica Scurr¹, David J Collins², Ian Chau³, David Cunningham³, Martin O Leach⁴, and Dow-Mu Koh^1
1Radiology, Royal Marsden Hospital, Sutton, Surrey, United Kingdom, ²CRUK and EPSRC, Sutton, Surrey, United Kingdom, ³Oncology, Royal Marsden Hospital, Sutton, Surrey, United Kingdom, ⁴Institute of Cancer Research, Sutton, Surrey, United Kingdom

We describe the prevalence and associated imaging findings in patients with colorectal hepatic metastases treated with chemotherapy who demonstrated reticular T1 hypointensity on the hepatocellular phase of Gd-EOB-DTPA enhanced MR imaging. This sign is only observed in patients treated with oxaliplatin based chemotherapy, and is associated with sinusoidal congestion or dilatation at histology. Reticular T1 hypointensity on the hepatocellular phase Gd-EOB-DTPA enhanced imaging appears to be a useful non-invasive sign for sinusoidal congestion resulting from oxaliplatin treatment toxicity in the liver.

Naoki Kanata¹, Takeshi Yoshikawa¹, Yoshiharu Ohno¹, Tomonori Kanda¹, Koji Uchida², Hisanobu Koyama¹, Kazuhiro Kitajima¹, Satoru Takahashi¹, and Kazuro Sugimura^1
1Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Radiology, Shimane University Faculty of Medicine, Izumo, Shimane, Japan

Dynamic CT and CTHA are more suitable modalities than EOB-enhanced MRI for evaluation of arterial blood supply in HCC. This should be taken into account for diagnosis and management of HCC.

Kristina Imeen Ringe¹, Elmar Merkle², Jan Hinrichs¹, Frank Wacker¹, and Bernhard Meyer^1
1Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Niedersachsen, Germany, ²Department of Radiology, Duke University Medical Center, United States

The purpose of this study was to analyze the hepatobiliary excretion of Gd-EOB-DTPA into different segments of the hepatobiliary system in 111 patients with primary sclerosing cholangitis (PSC) and to work out a possible correlation with severity of disease. The results of our study show, that hepatobiliary excretion in patients with PSC is significantly delayed compared to patients with normal liver function, and further dependent on bilirubin level, necessitating eventual adjustments of the MR imaging protocol.

Na-Young Shin¹, Myeong-Jin Kim¹, Joon Seok Lim¹, Mi-Suk Park¹, Yong-Eun Chung¹, Jin-Young Choi¹, Ki Whang Kim¹, and Young-Nyun Park^1
1Yonsei University Severance Hospital, Seoul, Korea

To assess whether hepatobiliary phase images of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) is a diagnostic finding of sinusoidal obstruction syndrome (SOS) in patients with hepatic metastases who have undergone chemotherapy, we retrospectively analysed EOB-MRI of 42 patients who had undergone chemotherapy before hepatic resection of colorectal hepatic metastases using a 5-point scale. Reticular hypointensity on hepatobiliary phase images of EOB-MRI is highly specific for the diagnosis of SOS in patients with treated colorectal hepatic metastases with good interobserver agreement.

MUKTA Dilipkumar AGRAWAL¹, Kevin W Mennitt¹, Honglei Zhang¹, Benjamin Samstein², Jean C Emond², Tomoaki Kato², and Martin R Prince^1,3
1Radiology, Weill Cornell Medical Center, New York, NY, United States, ²Liver transplantation surgery, Columbia University, New York, NY, United States,³Radiology, Columbia University, New York, NY, United States

PURPOSE: To assess low dose morphine for improved visualization of intrahepatic bile ducts on T1 magnetic resonance cholangiography (MRC), in potential liver donors. MATERIALS AND METHODS: 60 consecutive potential liver donors were assessed without (n=30) or with (n=30) intravenous morphine for Intra hepatic biliary branch order visualization, CBD diameter and overall image quality. RESULTS: At 45 and 60 minutes post morphine, mean intra hepatic bile duct branch order visualization, CBD diameter and over all image quality scores were greater compared to without morphine (p< 0.05). CONCLUSION: Intravenous low dose morphine distends and improves visualization of bile ducts on T1 MRC.

Kiyarash Mohajer^1,2, Jessica Robbins¹, Agnes Loeffler³, Richard Bruce¹, and Scott Reeder^1
1Radiology, University of Wisconsin, Madison, WI, United States, ²Radiology, UCLA, Los Angeles, CA, United States, ³Pathology, University of Wisconsin, Madison, WI

differentiation of hepatic adenoma (HA) and focal nodular hyperplasia (FNH) is important because HA’s are often resected due to risk of hemorrhage and risk of malignant degeneration, while FNH’s require no intervention. Characterization of HA vs. FNH with extracellular gadolinium-based contrast-agents is challenging because imaging characteristics during dynamic contrast imaging can be similar. The recent FDA approval of a new hepatobiliary agent (gadoxetic acid) offers new opportunities to characterize HA and FNH. However, there are very few reported cases with pathological-imaging correlation. In this work, we report the imaging characteristics of 6 histologically proven HA and 34 FNH lesions.

Anja Fischer^1,2, Oliver Kraff^1,2, Stephan Orzada^1,2, Lena C. Schäfer^1,2, Mark E. Ladd^1,2, Lale Umutlu^1,2, and Thomas C. Lauenstein^1
1Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen, Germany, ²Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany

MR imaging of the liver was investigated at 7 Tesla using Gadoxetic acid for depiction of the intra- and extrahepatic biliary tract. A custom-built eight-channel RF transmit/receive body coil and RF shimming were used. In 10 healthy volunteers, dynamic T1-weighted 3D VIBE and 3D FLASH inversion recovery sequences were acquired in the hepatobiliary phase. For comparison, all volunteers underwent a conventional T2-weighted MRCP at 3T. Initial results demonstrate feasibility, showing both benefits and limitations of this technique.

Tsutomu Tamada¹, Atsushi Higaki¹, Tomohiro Sato¹, Akihiko Kanki¹, Hiroki Higashi¹, Akira Yamamoto¹, and Katsuyoshi Ito^1
1Radiology, Kawasaki Medical School, Kurashiki City, Okayama, Japan

The �gperipheral washout sign�h in the late phase of dynamic contrast-enhanced MR imaging (DCE-MRI) using purely extracellular Gd chelates has been considered as a specific sign of malignant hepatic tumors such as hepatic metastases. We compared the frequency of the presence of �gperipheral low intensity sign�h between the hepatic hemangiomas and the hepatic metastases on the hepatobiliary phase of DCE-MRI obtained with Gd-EOB-DTPA. As the results, radiologists should recognize that peripheral low intensity sign is not specific for malignant tumors such as liver metastases, and can be seen even in hepatic hemangiomas on hepatobiliary phase of Gd-EOB-DTPA enhanced MR imaging.

Takeshi Yoshikawa¹, Nobukazu Aoyama², Yoshiharu Ohno¹, Akira Suwa³, Katsusuke Kyotani², Tomonori Kanda¹, Naoki Kanata¹, Hisanobu Koyama¹, Kazuhiro Kitajima¹, Satoru Takahashi¹, Hideaki Kawamitsu², and Kazuro Sugimura^1
1Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Division of Radiology, Kobe University Hospital, Kobe, Hyogo, Japan, ³Philips Electronics Japan, Tokyo, Japan

We optimized imaging parameters of Gd-EOB-DTPA-enhanced T2WI and DWI sequences in phantom and clinical studies for time-saving liver MRI.On post-contrast T2WI and DWI images, signal intensities and ADC values are severely affected by EOB concentration unless imaging parameters are carefully chosen. Post-contrast T2WI and DWI should be carefully applied especially to rare conditions.

Bengt Norén^1,2, Mikael Fredrik Forsgren^2,3, Olof Dahlqvist Leinhard^2,3, Nils Dahlström^1,2, Johan Kihlberg^1,2, Thobias Romu^2,4, Stergios Kechagias^5,6, Sven Almer^6,7, Örjan Smedby^1,2, and Peter Lundberg^2,3
1Depts of Medical and Health Sciences (IMH), Division of Radiological Sciences, Linköping University, Linköping, Sweden, ²Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden, ³Depts of Radiation Physics, Linköping University and Radiation Physics, UHL County Council of Ostergotland, Linköping, Sweden, ⁴Depts of Biomedical Engineering (IMT), Linköping University, Linköping, Sweden, ⁵Depts of Medical and Health Sciences (IMH), Division of Cardiovascular Medicine, Linköping University, Linköping, Sweden, ⁶Depts of Endocrinology and Gastroenterology, UHL County Council of Ostergotland, Linköping, Sweden, ⁷Depts of Clinical and Experimental Medicine (IKE), Divison of Gastroenterology and Hepatology, Linköping University, Linköping, Sweden

The purpose of this prospective study was to quantitatively measure the hepatocyte-specific uptake of Gd-EOB-DTPA using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and compare it with histopathological grading of fibrosis. The biopsy scores were grouped into no/mild fibrosis (F0-2, n=27) and advanced fibrosis (F3-4, n=11). Applying a new quantification procedure for calculation of the hepatocyte specific contrast uptake, this study can confirm that impaired hepatobiliary function severely influences the hepatocyte-specific uptake of Gd-EOB-DTPA and shows promising results for a non-invasive approach to separate mild liver fibrosis from advanced, something pure SI-based contrast ratios may fail to distinguish.

Akihiro Nishie¹, Yoshiki Asayama¹, Kousei Ishigami¹, Daisuke Kakihara¹, Tomohiro Nakayama¹, Yasuhiro Ushijima¹, Yukihisa Takayama¹, Ken Shirabe¹, Nobuhiro Fujita¹, masakazu Hirakawa¹, and Hiroshi Honda^1
1Kyushu University, Fukuoka, Fukuoka, Japan

For the first time we focused on the peritumoral decreased uptake area of Gd-EOB-DTPA (PDUAE) in HCC and investigated the significance of this “pseudolesion” by comparing variable clinical and pathological factors. As a result, PDUAE was associated with vascular invasion. When the presence of PDUAE was used as an indicator of vascular invasion, relatively high diagnostic performance was obtained. In addition, the vascular invasion of our enrolled cases was “microscopic”. In general, it remains difficult to detect “microscopic” vascular invasion on dynamic CT or MRI. Our results suggested that “microscopic” vascular invasion could be predicted with Gd-EOB-DTPA-enhanced MRI with ease.

Takeshi Yoshikawa¹, Nobukazu Aoyama², Yoshiharu Ohno¹, Akira Suwa³, Katsusuke Kyotani², Tomonori Kanda¹, Naoki Kanata¹, Hisanobu Koyama¹, Kazuhiro Kitajima¹, Satoru Takahashi¹, Hideaki Kawamitsu², and Kazuro Sugimura^1
1Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Division of Radiology, Kobe University Hospital, Kobe, Hyogo, Japan, ³Philips Electronics Japan, Tokyo, Japan

The effects of EOB on T2WI, DWI, and balanced FFE were assessed at both 1.5 T and 3T scanners to optimize imaging parameters in EOB-enhanced liver MRI. SNR in the images and ADC values were severely affected by EOB concentration. The filed-strength of scanner affected patterns of neither SNR nor ADC changes. Imaging parameters should be carefully chosen for EOB-enhanced T2WI, DWI, and balanced FFE.

Kristina Imeen Ringe¹, Hueseyin Bektas², Bastian Ringe², Patrick Opherk¹, Angela Reichelt¹, Joachim Lotz³, Frank Wacker¹, and Bernhard Meyer^1
1Department of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Niedersachsen, Germany, ²Department of General-, Visceral- and Transplantation Surgery, Hannover Medical School, Hannover, ³Department of Diagnostic Radiology, University Hospital Göttingen, Göttingen

The purpose of this prospective study was to assess the added value of the hepatocyte specific contrast agent gadoxetate disodium for characterization and staging of tumors in patients with malignant central bile duct stenosis. Intraoperative findings were used as gold standard. The results of our study show, that the application of gadoxetate disodium improves assessment of tumor extension, which is necessary to define tumor resectability. In this context images acquired in the late hepatocyte phase proved most useful for exact tumor delineation.

Mary Charlotte Stephenson¹, Richard D Johnston², Eleanor F Cox¹, Elisa Placidi¹, Guruprasad P Aithal², Ian A MacDonald³, and Peter G Morris^1
1SPMMRC, School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, ²Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, ³School of Biomedical Sciences, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom

Fructose has been linked to rises in obesity and liver disease. This study observes the effects of an isoenergetic diet containing excess fructose or glucose on hepatic and muscle lipid stores, and ³¹P metabolite levels, and compares these with a hyperenergetic diet with equivalent excess fructose or glucose. We show that 2 weeks of a high fructose isoenergetic diet does not increase lipid deposition. Increasing energy intake leads to increased levels of hepatic lipid and inorganic phosphate. However, these changes occur following hyperenergetic fructose and glucose diets, indicating that the effects are more likely the result of energy overfeeding.

Kayvan R. Keshari¹, Andrew Taylor¹, Zhen Jane Wang¹, John Kurhanewicz¹, Daniel B. Vigneron¹, and David M. Wilson^1
1Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, CA, United States

Non-alcoholic fatty liver disease (NAFLD) is recognized as the most prevalent liver abnormality in the United States. Although changes in redox have been implicated in the onset and progression of NAFLD, methods to image this disease are limited. In recent work, hyperpolarized [1-13C] dehydroascorbate (DHA), which is rapidly converted to Vitamin C in vivo, has been identified as an endogenous redox sensor for non-invasive MR imaging. In this study, we demonstrate the use of HP [1-13C] DHA to image redox changes in a standard model of NAFLD and correlate these findings with standard 1H imaging and histopathology.

Nathan S Artz¹, Catherine DG Hines², Jens-Peter Kuhn¹, Alejandro Roldan-Alzate¹, Rashmi Agni³, Steven Brunner⁴, Guang-Hong Chen⁴, and Scott B Reeder^1,4
1Department of Radiology, University of Wisconsin, Madison, WI, United States, ²Pharmaceuticals, Merck & Co., Inc, Philadelphia, PA, United States,³Department of Surgical Pathology, University of Wisconsin, Madison, WI, United States, ⁴Department of Medical Physics, University of Wisconsin, Madison, WI, United States

Quantitative MRI methods have shown great promise as non-invasive biomarkers of hepatic steatosis, with validation studies performed in phantoms, animal models, and patients. However, CT and increasingly Dual-Energy CT (DECT), is used for most advanced imaging studies of the abdomen. The purpose of this study was to compare MRI and DECT for fat quantification using tissue triglyceride (TG) concentration as the reference, in an ob/ob mouse model. Excellent correlation (r >= 0.93,p<0.001) was observed for both CT attenuation (HU) and MRI fat-fraction compared with tissue TG and each other. Other DECT measurements demonstrated good, but inferior, correlation with TG and MRI.

Xeni Deligianni¹, Klaus Scheffler^2,3, and Oliver Bieri^1
1Division of Radiological Physics - Department of Radiology and Nuclear Medicine, University of Basel Hospital, Basel, Switzerland, ²MTC Department, MPI for Biological Cybernetics, Tübingen, Germany, ³Dept. Neuroimaging and MR-Physics, University of Tübingen, Tübingen, Germany

Assessing the fat liver properties is of increased clinical interest, such as for quantifying non-alcoholic fatty liver disease. MR imaging of liver fat has been proven to be a valuable non-invasive alternative to biopsy. A 3D multi-echo gradient echo sequence with sequentially shifted echo times is proposed for whole liver fat tissue characterization within a single breath-hold. The signal time course is analyzed using a voxel-wise singular value decomposition to yield water-fat fractions and corresponding T2* relaxation times. This approach provides a robust way for fast and reliable analysis of water and fat signals.

Xiaodong Zhong¹, Puneet Sharma², Wesley D Gilson³, Vladimir Jellus⁴, Stephan Kannengiesser⁴, Brian M Dale⁵, Berthold Kiefer⁴, and Diego R Martin^2
1MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, ²Radiology Department, University of Arizona, Tucson, AZ, United States,³Corporate Research, Siemens Corporation, Baltimore, MD, United States, ⁴Siemens AG Healthcare Sector, Erlangen, Germany, ⁵MR R&D Collaborations, Siemens Healthcare, Cary, NC, United States

In this study, a single breath-hold multi-echo 3D GRE Dixon method with whole liver coverage and high slice resolution was developed and preliminary evaluation was performed in clinical patients. This 3D GRE Dixon method produced similar liver fat quantification results to those measured with 2D multi-echo GRE Dixon, and high-speed T2-corrected multiple-echo 1H-MRS (HISTO) as a reference standard, for the protocols and patients tested in this study. This single breath-hold 3D GRE Dixon method may be adopted in the routine clinical scan and have great potential for evaluating the hepatic steatosis for obesity related liver diseases.

Shane A Wells¹, Diego Hernando¹, Karl K Vigen¹, and Scott B Reeder^1,2
1Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, ²Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States

Chemical-shift based water-fat separation methods with R2*-correction can accurately quantify fat-fraction and R2*, as surrogate biomarkers of hepatic steatosis and iron overload. New hepatobiliary contrast agents dramatically alter the T1 and R2* of liver and may impact quantification of fat and iron. In this work, we investigate the impact of a hepatocyte-specific contrast agent (gadoxetic acid) on fat-fraction and R2*. We demonstrate that fat-fraction is unaffected by gadoxetic acid, so long as low flip angles are used. However, gadoxetic acid increases the apparent R2* demonstrating that quantification of iron overload should always be performed prior to contrast administration.

Caroline L Hoad¹, Naaventhan Palaniyappan², Carolyn Costigan¹, Eleanor F Cox¹, Luca Marciani², Philip Kaye³, Neil Guha², Robin C Spiller², Penelope A Gowland¹, Guruprasad P Aithal², and Susan T Francis^1
1Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, ²Nottingham Digestive Diseases Centre, NIHR Biomedical Research Unit, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom, ³Department of Cellular Pathology, Nottingham University Hospitals NHS Trust, Derby Royal Hospital, Derby, United Kingdom

Reproducibility of whole liver relaxation time measurements using respiratory triggered echo-planar imaging was carried out on 8 healthy volunteers, scanned on 2 separate occasions. Modal T₁, T₂ and T₂^* parameters were obtained from fitting a Gaussian curve to the histograms of the fitted data. The coefficient of variance (CV) was 1.5 %, 3.1 % and 4.3 % for T₁, T₂ and T₂^* respectively. Inter- and Intra-observer variability was assessed using relaxation time data sets from 20 chronic liver disease patients. Inter- and intra-observer CVs were below 1% suggesting that biological variability and scanner related noise dominated the CVs of the reproducibility data.

Benjamin Leporq¹, Helene Ratiney¹, Herve Saint-Jalmes^2,3, Frank Pilleul^1,4, and Olivier Beuf^1
1CREATIS; CNRS UMR 5220; INSERM U1044; INSA-Lyon; UCBL Lyon 1, Villeurbanne, Rhône-Alpes, France, ²LTSI; Inserm U642; Université Rennes 1, Rennes, Bretagne, ³CRLCC; Centre Eugène Marquis, Rennes, Bretagne, France, ⁴Hospices civils de Lyon; CHU Edouard Herriot, Lyon, Rhône-Alpes, France

In Western countries, Non-Alcoholic Fatty Liver Disease (NAFLD) is the most common cause of chronic liver diseases. Because NAFLD can evolve into Non-Alcoholic Steato-Hepatitis and may lead to liver fibrosis up to cirrhosis, a clinical follow-up of NAFLD would be valuable. This work presents a MR magnitude-based technique for liver fat volume fraction quantification with independent fat and water T2* estimations, T1-related bias and spectral complexity of fat corrections using a two-angles multiple gradient-echo acquisition. The method described was applied in-vivo at 1.5T in a prospective study and at 3.0T on healthy subjects. It was additionally compared with 1H MRS on fat-water phantoms.

Janakan Satkunasingham¹, Ami Shah², Stephan Kannengiesser³, Andre De Oliveira³, Marcello Facciuto², and Bachir Taouli^2
1Queen’s University, Kingston, Ontario, Canada, ²Mount Sinai School of Medicine, New York, NY, United States, ³Siemens Healthcare, Erlangen, Germany

In this study involving a large number of patients (n=211), we have compared the diagnostic accuracy of 2 point Dixon and 3 point Dixon sequences to T2-corrected multiecho MR spectroscopy used as the reference standard. Hepatic iron deposition was determined using a breath-hold multi-echo T2* sequence. Results demonstrated the superiority of the 3 point Dixon over the 2 point Dixon method for quantifying hepatic fat, mainly related to the presence of concomitant iron deposition.

Michel Louis Lauzon^1,2, Farzana Sayani³, Karen Valentine³, Richard Frayne^1,2, and Houman Mahallati^1,2
1Radiology, University of Calgary, Calgary, AB, Canada, ²Seaman Family MR Research Centre, Calgary, AB, Canada, ³Medicine, University of Calgary, Calgary, AB, Canada

The current gold standard for quantification of liver iron content (LIC) in iron-overloaded states is liver biopsy, an invasive and potentially risky procedure. Safe non-invasive MR-based methods of measuring LIC are promising alternatives. Here, we quantify LIC using a multi-echo single breath-hold T2*-weighted spoiled gradient-recalled echo sequence at 3.0 T, and compare the results to biopsy. The mean MR-derived LIC estimates were similar to biopsy (to within 2.5 mg of iron per gram of dry liver weight), and MR covered a much larger liver extent than biopsy, had a stringent confidence interval, and was well tolerated by patients.

Mustafa Rifaat Bashir¹, Brian M Dale², and Elmar Max Merkle^1
1Radiology, Duke University Medical Center, Durham, NC, United States, ²Siemens Medical Solutions, Cary, NC, United States

Multi-echo gradient echo based MRI techniques have emerged as a useful clinical tool for estimating hepatic iron concentration by measuring liver R2*. Systematic and random errors can occur in the R2* solution based on the number of echoes used for the calculation. We explore the propagation of these errors, and propose and analyze a technique for reducing error by selecting an optimized number of echoes for the calculation. We compare this with standard techniques using Monte Carlo simulations and patient data.

Diego Hernando¹, Jens-Peter Kühn^1,2, and Scott B Reeder^1,3
1Department of Radiology, University of Wisconsin-Madison, Madison, WI, United States, ²Department of Diagnostic Radiology, University Greifswald, Greifswald, MV, Germany, ³Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States

R2*-MRI can be used to assess body iron deposition for diagnosis, staging and treatment monitoring of iron overload. However, the apparent R2* is often confounded by the presence of fat, noise floor and susceptibility effects (e.g., near tissue/air interfaces). Recently, a method was introduced to perform fat-corrected, complex-fitting, and susceptibility-corrected R2* mapping. In this work, we quantitatively evaluate the susceptibility correction in a cohort of 35 healthy subjects without iron overload. Uncorrected measurements showed significant deviations in R2*. These deviations were largely corrected by susceptibility-corrected R2*. This technique may be important for the assessment of iron deposition in the liver.

An Tang^1,2, Lucas Shanholtzer², Nikolaus Szeverenyi², Rohit Loomba³, Michael Peterson⁴, Tanya Wolfson⁵, Anthony C. Gamst⁵, Richard L. Ehman⁶, and Claude B Sirlin^2
1Radiology, University of Montreal, Montreal, Qc, Canada, ²Radiology, University of California, San Diego, San Diego, California, United States, ³Division of Gastroenterology, Hepatology, and Medicine, University of California, San Diego, San Diego, California, United States, ⁴Department of Pathology, University of California, San Diego, San Diego, California, United States, ⁵Biostatistics, University of California, San Diego, San Diego, California, United States, ⁶Radiology, Mayo Clinic, Rochester, Minnesota, United States

Liver stiffness was measured by magnetic resonance elastography (MRE) and compared with histology. MRE performed at 3.0 T with 1 axis and 3 axes motion sensitization at multiple frequencies showed strong correlations with fibrosis stage and a trend toward higher stiffness with increasing lobular inflammation grades in adults with NAFLD. These results confirm that MRE is useful for noninvasive assessment of fibrosis not only in a variety of chronic liver disease but also in a population of NAFLD patients.

Scott Charles Beeman¹, Joseph F Georges², Lawrence Mandarino^3,4, Jorge Rakela⁵, and Kevin M Bennett^1
1Bioengineering, Arizona State University, Tempe, Arizona, United States, ²School of Life Sciences, Arizona State University, Tempe, Arizona, United States, ³School of Life Sciences, Arizona State University, Tempe, AZ, United States, ⁴Department of Medicine, Mayo Clinic in Arizona, Scottsdale, AZ, United States, ⁵Department of Gastroenterology and Hepatology, Mayo Clinic in Arizona, Scottsdale, AZ, United States

The goal of this work was to develop an MRI-based technique for detection of changes to the ECM of the hepatic sinusoid during chronic liver disease. Using cationic ferritin (CF), an ECM-targeted nanoparticle contrast agent, we show that T₂* measurements in healthy animals decrease 50% after injection of CF while rats with chronic liver disease show no change in T₂* after CF injection. This is likely due to the structural changes to the ECM that occur during chronic liver disease. These results suggest that MRI and CF may be used to detect ECM-specific changes in chronic liver diseases.

Debra E. Horng^1,2, Diego Hernando¹, Catherine D.G. Hines³, and Scott B. Reeder^1,2
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, ²Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, ³Merck Research Laboratories, West Point, PA, United States

We compared the performance of fat-fraction quantification using chemical shift encoded MRI using single-R₂* and dual-R₂* correction methods, using MR spectroscopy (MRS) as the reference standard. From a group of 97 patients, 20 patients with fat fraction > 10% were identified, and chemical shift encoded fat-water imaging was performed. Fat-fraction was measured from the imaging data using both single-R2_* and dual-R₂* correction. Fat-fraction estimates were compared to co-registered spectroscopy measurements: single-R₂* correction demonstrated higher agreement. Single-R₂* modeling is more accurate than dual-R₂* modeling for hepatic fat quantification in patients, even in those with high hepatic fat concentrations.

Christina Marie Chingkoe¹, Errol Colak¹, Vikram Prabhudesai¹, Marie Faughnan², and Anish Kirpalani^1
1Department of Medical Imaging, St. Michael's Hospital, Toronto, Ontario, Canada, ²Division of Respirology and Director of HHT Program, St. Michael's Hospital, Toronto, Ontario, Canada

Hereditary hemorrhagic telangiectasia (HHT), an autosomal dominant disorder of variable penetrance, is characterized by the presence of mucocutaneous and visceral vascular malformations (VMs). Hepatic involvement occurs in 40% of patients with HHT. We perform liver MRI routinely in HHT patients to document hepatic VMs and to evaluate for hepatic complications of HHT. In this presentation, the MRI features of the hepatic manifestations of HHT are reviewed. These include intrahepatic shunting (arterioportal, arteriosystemic and portosystemic), discrete VMs (capillary telangiectasia, confluent vascular masses, arteriovenous malformations), focal nodular hyperplasia, sclerosing cholangitis from ischemic biliopathy, and potential complications (including hemosiderosis, cholangitis, intrahepatic abscess).

Kenji Matsuzaki¹, Mayumi Takeuchi¹, and Masafumi Harada^1
1Department of Radiology, University of Tokushima, Tokushima, Tokushima, Japan

Preserved intrahepatic vessels may be observed within various benign and malignant pathologies in the liver as "vessel-penetrating sign" (VPS) on imaging. MRI has an advantage to demonstrate vessels without the administration of contrast medium as flow voids on spin echo sequences with long TR; echo planar diffusion-weighted imaging, or as high signal intensity structures on gradient echo sequences with steady state free precession. The presence of VPS suggests infiltrative tumor growth, highly non-destructive tumors, mass formed by the aggregated malignant tumors, or benign tumor-like conditions. We present diagnostic imaging features of various liver lesions, which show VPS, with pathologic correlation.

Anneloes E. Bohte¹, Aart J. Nederveen¹, Paul F.C. Groot¹, Annikki de Niet², Peter L.M. Jansen², Ralph Sinkus³, and Jaap Stoker^1
1Radiology, Academic Medical Center, Amsterdam, Netherlands, ²Gastroenterology, Academic Medical Center, Amsterdam, Netherlands, ³Radiology, Hôpital Beaujon, Paris, France

Liver fibrosis can be detected by means of Magnetic Resonance Rheology (MRR, also known as MR elastography). It has the potential to replace liver biopsy in patients with chronic liver disease. If this measurement becomes part of the clinical routine, one needs to know which changes in liver elasticity and viscosity over time can be accurately measured. In this study we define a threshold for detecting a significant change in both liver elasticity and viscosity in repeated MRR measurements in a group of 27 subjects containing both healthy volunteers and patients with viral hepatitis B/C.

Sudhakar Kundapur Venkatesh¹, Utaroh Motosugi², Gang Wang¹, Tamoaki Ichikawa², Tsutomo Araki², Seng Gee Lim³, and Aileen Wee^4
1Diagnostic Imaging, National University Health System, Singapore, Singapore, Singapore, ²Radiology, University of Yamanashi, Yamanashi, Japan,³Gastroenterology and Hepatology, National University Health System, Singapore, Singapore, ⁴Pathology, National University Health System, Singapore, Singapore, Singapore

Chronic liver diseases lead to fibrosis and cirrhosis. The degrees of fibrosis and distribution pattern are different in chronic liver diseases from varied etiologies. MR Elastography is an accurate technique for quantification of liver stiffness which correlates with stages of fibrosis. We evaluated liver stiffness in histology proven cases of chronic hepatitis B and chronic hepatitis C from two leading centres in Asia. Our preliminary results show no significant differences in stiffness values in the livers of different stages of fibrosis from the two etiologies. The cut-off values for diagnosing significant fibrosis also did not show any significant difference.

Meng Yin¹, Kevin J Glaser¹, Jason L Bakeberg², Christopher J Ward², Peter C Harris², and Richard L Ehman^1
1Radiology, Mayo Clinic, Rochester, MN, United States, ²Nephrology and Hypertension, Mayo Clinic, Rochester, MN, United States

A feasibility study was performed for measuring hepatic shear stiffness in small animals to identify whether a selected animal model merits further study to see if hepatic stiffness correlates with hepatic inflammation and fibrosis progression. The results of this preliminary study demonstrated that increased liver stiffness is an early marker of disease progress in a Pkhd1 mouse model. If these results can be further confirmed with more sophisticated mechanical models to separate fluid-related inflammation and matrix-related fibrosis effects, MRE may provide means to distinguish hepatic inflammation before the onset of hepatic fibrosis.

Russell N. Low^1,2, and Tarek Hassanein^3
1Sharp and Children's MRI Center, San Diego, California, United States, ²San Diego Imaging, San Diego, CA, United States, ³Liver Centers of Southern California, Coronado, CA, United States

MR Elastography (MRE) noninvasively assesses liver stiffness and can rapidly provide information about the stage of liver fibrosis. Our comparisons of the results of MRE with liver biopsy show excellent correlation that validates its routine use for liver imaging in our practice.

Takeshi Yoshikawa¹, Nobukazu Aoyama², Yoshiharu Ohno¹, Akira Suwa³, Katsusuke Kyotani², Tomonori Kanda¹, Naoki Kanata¹, Hisanobu Koyama¹, Kazuhiro Kitajima¹, Satoru Takahashi¹, Hideaki Kawamitsu², and Kazuro Sugimura^1
1Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Division of Radiology, Kobe University Hospital, Kobe, Hyogo, Japan,³Philips Electronics Japan, Tokyo, Japan

We developed portal spin labeling technique for evaluation of portal perfusion in the liver and liver tumors and report the initial results in clinical cases.

Alejandro Roldán-Alzate¹, Eric Niespodzany¹, Alex P Frydrychowicz¹, Benjamin R Landgraf¹, Oliver Wieben^1,2, and Scott B Reeder^1,2
1Radiology, University of Wisconsin, Madison, Wisconsin, United States, ²Medical Physics, University of Wisconsin

In addition to co-registered vascular anatomy, functional information, and analysis of flow patterns, 4D velocity mapping can be used to quantify blood flow. Using time resolved PC-MRI with 3D radial undersampling (PC-VIPR), a large data volume can be assessed. Here, the ability of PC-VIPR to quantify changes in portal and splanchnic blood flow after a meal challenge was investigated. Results revealed significant increases in portal blood flow in response to the meal challenge, demonstrating the potential of PC-VIPR for monitoring of treatment such as beta-blockers and TIPS in patients with portal hypertension.

David Bowden¹, Richard Black², Lorenzo Mannelli³, Andrew Patterson¹, Andrew N Priest², Andrew B Gill², Ilse Joubert¹, Peter Beddy⁴, Owen Thomas¹, and David J Lomas^1
1Department of Radiology, Addenbrooke’s Hospital & University of Cambridge, Cambridge, Cambridgeshire, United Kingdom, ²Department of Medical Physics, Addenbrooke’s Hospital & University of Cambridge, Cambridge, Cambridgeshire, United Kingdom, ³Department of Radiology, University of Washington, Seattle, WA, United States, ⁴Department of Radiology, St.Jame's Hospital, Dublin, Ireland

Blood Oxygen Level Dependent (BOLD) MRI is a non-invasive technique that detects signal changes in tissues that occur in response to changes in blood flow. Technical challenges have presented significant barriers to its use outside the brain. Via the study of nine patients with hepatocellular carcinoma on a background of diffuse liver disease, we have demonstrated significant differences in BOLD effect between normal liver, diseased liver and primary liver tumours (HCC) at 3 Tesla using the simple challenge strategy of increased inspired oxygen. Normal, control subjects with healthy livers demonstrated no significant BOLD effect.

Xiaodong Zhang¹, Yudong Zhang², Xuedong Yang², Xiaoying Wang^1,2, Hongyu An³, Jue Zhang^1,4, and Jing Fang^1,4
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, ²Dept. of Radiology, Peking University First Hospital, Beijing, China,³Department of Radiology and Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, ⁴College of Engineering, Peking University, Beijing, China

Renal R2 provides critically important information to assess the renal oxygen metabolism in both normal and disease states. An asymmetric spin echo (ASE) single shot echo planar imaging (EPI) sequence can provide rapid measurements of R2 in human kidney. In addition, the proposed ASE R2measurement is highly reproducible and is sensitive to renal oxygenation changes under pharmacological conditions

Xiang He¹, Ayaz Aghayev¹, Serter Gumus¹, Dmitriy A Yablonskiy², and Kyongtae Ty Bae^1
1Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States, ²Mallinckrodt Institute of Radiology, Washington University in St Louis, St Louis, Missouri, United States

While a semi-qualitative MR BOLD effect (R2*) has been widely adopted to assess intra-renal oxygenation, the underlying biophysical mechanism associating between hemodynamic parameters and renal BOLD effect (R2*) has not been established. In this study, a theoretical and experimental framework for MR-based quantitative BOLD (qBOLD) technique was investigated to measure absolute intra-renal blood oxygenation. A 2D GEPCI (Gradient Echo Plural Contrast Imaging) pulse sequence was used to measure T2* decay of renal MR signal. Our proposed renal-qBOLD method allows us to quantitatively assess regional renal blood oxygenation in the baseline state and under a renal physiological challenge.

Jan Hentschel¹, Lajos Marko², Erdmann Seeliger³, Dominik N. Müller^2,4, Andreas Pohlmann¹, and Thoralf Niendorf^1,2
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrück-Center for Molecular Medicine (MDC), Berlin, Germany, ²Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max-Delbrück-Center, Berlin, Germany, ³Institute for Vegetative Physiology, Charité Medical Faculty, Berlin, Germany, ⁴Department of Experimental Medicine I, Nikolaus-Fiebiger-Center for Molecular Medicine, Friedrich-Alexander-University, Erlangen-Nürnberg, Germany

Renal medullary hypoperfusion and hypoxia play a pivotal role in acute kidney injury (AKI). This study examines the correlation between MRI and NGAL/KIM1 in mouse AKI including ischemia/reperfusion injuries of different severity to elucidate the link between changes in T₂ and kidney physiology. The T₂ values derived from the medulla and cortex of clipped kidneys showed a strong correlation with NGAL. A similarly strong correlation was observed between KIM1 and T₂ deduced from the medulla. This indicates that T₂ -mapping may be useful as a non-invasive marker for the characterization of pathophysiological changes in mouse models of AKI.

Wen-Chau Wu^1,2, Mao-Yuan Su³, Chin-Cheng Chang³, and Kao-Lang Liu^3
1Graduate Institute of Oncology, National Taiwan University, Taipei, Taiwan, ²Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, ³Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan

Arterial spin labeling (ASL) and dynamic contrast enhanced (DCE) imaging are two established MRI techniques for quantitative perfusion measurement although their feasibility in the kidneys is still under investigation. One major challenge is glomerular filtration of the tracers used. Extended biophysical models have been proposed to account for dual outputs and/or inputs of tracers, which usually require additional scans and higher contrast-to-noise ratio (CNR). In this study, we assessed the feasibility and reproducibility of ASL and DCE in renal blood flow measurement using the original models and examined their CNR both in time and in space. Technical limitations were discussed.

Eleanor F Cox¹, Emma L Hall¹, Paula L Croal¹, Ian D Driver¹, and Susan T Francis^1
1SPMMRC, School of Physics & Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom

The longitudinal relaxation time (T1) of tissues has been suggested to be a potential biomarker for tissue oxygenation and previous studies have seen a reduction in T1 on breathing 100% oxygen. We induced hyperoxia in 5 subjects at 3T, and using a modified respiratory triggered IR-TrueFISP sequence and formed maps of the change in R1 in the renal cortex, spleen and liver during normoxia and hyperoxia. There was a reduction in R1 in the spleen and renal cortex, but no change in R1 in the liver on hyperoxia.

Marla Shaver¹, and Michael Noseworthy^2,3
1School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada, ²School of Biomedical Engineering, Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada, ³Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada

In this study we used real-time BOLD imaging to investigate whether breath holding can play a significant role in modulating kidney microvasculature. Images were acquired using a T2* weighted GRE EPI sequence. Subjects were instructed to hold their breath, breath when necessary and repeat for the duration of the scan. Data from regions of interest for the renal cortex and medulla were analyzed to identify any trends in the data. No consistent trends were found and it was concluded that breath holding during the acquisition of renal BOLD MRI does not have an effect on the data.

Andrew L Wentland^1,2, Arjang Djamali³, Shannon R Reese³, Sean B Fain¹, Thomas M Grist², Chris J Francois², Amanda J Kolterman², and Elizabeth A Sadowski^2
1Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States, ²Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States, ³Nephrology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States

While individual studies have used BOLD imaging to evaluate renal oxygen bioavailability in transplant patients with various forms of allograft dysfunction, no study has compared measurements between these groups. We compared measurements of oxygen bioavailability in healthy subjects with native kidneys, subjects with well-functioning renal allografts, and transplant patients undergoing chronic allograft nephropathy, acute tubular necrosis, and acute rejection. Medullary oxygen bioavailability was significantly higher in subjects with acute rejection than in the other four groups. No other significant differences were found. The inclusion of an MR perfusion technique in future studies may elucidate the mechanisms behind these abnormal measurements.

Jeff L. Zhang^1,2, Henry Rusinek³, Christopher Conlin^1,2, and Vivian S. Lee^1
1Department of Radiology, University of Utah, Salt Lake City, UT, United States, ²Department of Bioengineering, University of Utah, Salt Lake City, UT, United States, ³Department of Radiology, New York University

In this study we performed a voxel-by-voxel analysis for the vascular phase of low-dose Gd-enhanced MR renography data and assessed the impact of cardiac output-corrected AIF on the precision of renal perfusion measurements. The estimated perfusion and vascular volume fraction agreed with literature value. The variability of perfusion was remarkably reduced with the use of CO-based AIF correction.

Jing Wang¹, Yudong Zhang², Xuedong Yang², Xiaoying Wang^1,2, Jue Zhang^1,3, Jing Fang^1,3, and Xuexiang Jiang^2
1Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China, ²Department of Radiology, Peking University First Hospital, Beijing, China, ³College of Engineering, Peking University, Beijing, China

This study is aim to assess the effects of intravenous-injected iodinated contrast medium on intrarenal water diffusion using noninvasive DW-MRI. A sequential DW-MRI was performed on rabbit model to estimate the intrarenal apparent diffusion coefficient at 24 hours before and 1h, 24h, 48h and 72h after administration. As demonstrated by DW-MRI, intravenous iopamidol injection resulted in a successive reduction of intrarenal water diffusion, particularly in IS of kidney. This MR technique may be used as a noninvasive tool to perform a time course study of the pathogenesis associated with contrast-induced nephropathy.

Sudhakar Kundapur Venkatesh¹, Gang Wang¹, Thomas Paulraj Thamboo², Eugene Liu¹, Edwin PY Siew¹, and Vathsala Anantaram^3
1Diagnostic Imaging, National University Health System, Singapore, Singapore, Singapore, ²Pathology, National University Health System, Singapore, Singapore, Singapore, ³Nephrology, National University Health System, Singapore, Singapore, Singapore

Chronic allograft nephropathy is a common cause of renal transplant failure and characterized by interstitial fibrosis and tubular atrophy-IFTA. We investigated transplant stiffness and correlated with histological grade of IFTA. Our study did not show any significant correlation with stiffness and grade of IFTA suggesting that other changes including tubular atrophy, glomerulosclerosis and arteriolar hyalinosis and altered perfusion may contribute significantly to stiffness. Our study did show significant differences between normal group and those with IFTA. More work is needed for determining the utility of renal transplant stiffness measurement with MRE and its relation to the histological changes.

Lu-Ping Li¹, Hongyu An², Tammy Franklin¹, Ujala Bokhary¹, Anindya Sen¹, and Pottumarthi V Prasad^1
1Radiology Dept., Northshore University Healthsystem, Evanston, IL, United States, ²Radiology, University of North Carolina, Chapel Hill, NC, United States

R2* is widely used as a renal BOLD MRI parameter, but is inherently dependent on R2 in addition to the susceptibility induced relaxation, R2’. R2’ can be estimated using asymmetric spin echo (ASE) sequence. Preliminary data from 26 rats were acquired with this sequence before and after administration of iodinated contrast agents in a model of CIN. Our preliminary experience supports the feasibility of acquiring R2’ maps using ASE-EPI sequence in kidneys and that the similar trends observed with R2* and R2’ suggests that measured changes in R2* are primarily due to changes in susceptibility.

Jeff L. Zhang^1,2, Henry Rusinek³, Christopher Conlin^1,2, and Vivian S. Lee^1
1Department of Radiology, University of Utah, Salt Lake City, UT, United States, ²Department of Bioengineering, University of Utah, Salt Lake City, UT, United States, ³Department of Radiology, New York University

As microprobe pO₂ technique is not applicable for human kidneys, direct correlation between R2* and tissue pO2 has never been studied in human subjects. In order to validate BOLD as a marker of renal oxygenation we have measured the correlation (CC) between BOLD signal and renal functional parameters such as glomerular filtration rate (GFR) and tissue perfusion (F) in normal human kidneys. The strongest associations (CC > 0.60) were found for GFR/F_Med vs R2*_Med (0.68), GFR/F_Cx vs R2¡¯_Cx (0.65), and GFR/F_Med vs R2¡¯_Med (0.62).

Xingui Peng¹, Shenghong Ju¹, Fang Fang¹, and Gao-Jun Teng^1
1Medical School, Southeast University, Nanjing, Jiangsu province, China

Diabetic nephropathy has been associated with the presence of lipid deposits. This study aimed to determine whether in vivo MR imaging can evaluate the lipid changes noninvasively. Chemical shift imaging and T1WI were performed to measure lipid content and estimate adipose tissue distribution, respectively. Visceral adipose tissue and kidney lipid content in db/db mice was significantly higher than that of control group. The lipid accumulation in the renal cortex of db/db mice was significantly higher than that of renal medulla. Out results indicate that MRI will be used to study animal models and patients with renal diseases resulting from lipotoxicity.

Anindya Sen¹, Lu-Ping Li¹, Ujala Bokhary¹, Ioannis Koktzoglou¹, and Pottumarthi V. Prasad^1
1Department of Radiology, Northshore University Healthsystem, Evanston, IL, United States

Parametric maps, e.g. T1, T2, ADC (apparent diffusion coefficient) etc. are routinely used to evaluate functional changes in tissue. Regions of interest (ROI) measurements are commonly employed to evaluate the observed changes which may not fully characterize the spatial variations in the measurements inherently present in images. In this preliminary study, we have evaluated a histogram based analysis of R2* maps for renal BOLD MRI. Using centroid to represent the histogram distribution, we show that the displacement in the geometric centroids obtained pre- and post-furosemide could be used as a parametric measure for change.

Pottumarthi V. Prasad¹, Lu-Ping Li¹, Muhammad Haque¹, Anindya Sen¹, Ujala Bokhary¹, Heather Koenigs¹, Rajiv Agarwal², and Stuart Sprague^3
1Radiology, NorthShore University HealthSystem, Evanston, IL, United States, ²Medicine, Indiana University, Indianapolis, IN, United States, ³Medicine, NorthShore University HealthSystem, Evanston, IL, United States

Chronic kidney disease (CKD) involves progressive reduction in renal function and is associated with increasing levels of fibrosis and reduction in renal volume. Additionally, it is becoming clear that hypoxia plays a key role both in the initiation and progression of CKD. Here, preliminary data of renal volume, ADC and BOLD MRI measurements obtained in patients with CKD and healthy controls are presented. It is evident that enhanced hypoxia is present even at mild to moderate levels of CKD and there was correlation between R2* and ADC values, consistent with the hypothesis that hypoxia stimulates fibrogenesis.

Henrik J Michaely¹, Urs Benck², Stefan Haneder³, Uwe Göttmann⁴, Tobias Runge⁴, Bernhard K Krämer⁴, and Stefan O Schoenberg^3
1IKRN, University Medical Center Mannheim, Mannheim, Ba-Wu, Germany, ²V. Medical Clinic, University Medical Center Mannheim, Mannheim, ³IKRN, University Medical Center Mannheim, ⁴V. Medical Clinic, University Medical Center Mannheim

3T MR-imaging of rats with acute ischemic renal failure, Cyclosporin A toxicity and control was performed 36h after injection of ultra small particles of iron oxide (P904). Only in the acute renal failure signal decay in the medulla was seen which correlated with positive iron findings and Ed1 positive macrophages in immunohistology.

Dario Livio Longo¹, Alice Busato¹, Stefania Lanzardo², Federica Antico³, and Silvio Aime^1
1Molecular Imaging Center, University of Torino, Torino, Italy, ²Department of Clinical and Biological Sciences, University of Torino, Torino, Italy,³Department of Internal Medicine, University of Torino, Torino, Italy

pH is an important microenvironment parameter, in fact a number of disease states are associated with alterations in pH, such as ischemia, inflammation, infection and cancer, and many kidney injuries are associated with a perturbation of renal pH, therefore imaging techniques able to report in vivo on pH modifications would have a great relevance. The aim of the work was to investigate the use of Iopamidol as a MRI-CEST pH reporter of the disease evolution in glycerol-induced AKI model, exploiting the capability to image pH values in different regions for single kidneys.

Fabian Zimmer¹, Frank G. Zoellner¹, Simone Hoeger², Sarah Klotz², Charalambos Tsagogiorgas³, and Lothar R. Schad^1
1Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany, ²Department of Medicine V, University Medical Centre Mannheim, Heidelberg University, Mannheim, Germany, ³Clinic for Anaesthesiology and Intensive Care, Heidelberg University, Mannheim, Germany

The assessment of kidney function by measuring renal microvascular perfusion is crucial to diagnose and treat renal diseases at an early stage of progression. MRI provides two techniques to assess renal perfusion: Dynamic contrast-enhanced (DCE)-MRI and arterial spin labelling (ASL). In this study, ASL has been established to quantitatively measure renal cortical perfusion in rats with unilateral ischaemic acute renal failure. The ASL estimates were compared against those obtained by DCE-MRI. Both methods are in good agreement and show no statistical differences. Furthermore, both methods depict significant blood flow differences between healthy and diseased kidneys.

C. Chad Quarles¹, Feng Weng¹, Mohammed Tantawy¹, Rosie Jiang², Keiko Takahashi², Chuan-Ming Hao², Todd Peterson¹, Raymond Harris², and Takamune Takahashi^2
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ²O'Brien Mouse Kidney Physiology and Disease Center, Vanderbilt University, Nashville, TN, United States

MRI and ^99m Tc-MAG3 scintigraphy were used to serially assess the mouse kidney following unilateral ureteral obstruction (UUO). In UUO mice the renal pelvic space gradually expanded in obstructed kidneys as early as 1 day post ureteral ligation and the components of renal medulla, especially inner medulla and papilla, was remarkably decreased as the disease progressed. The ^99m Tc-MAG3 data revealed that renal perfusion is remarkably and rapidly reduced in UUO kidneys, whereas it is gradually increased in contra-lateral kidneys. In pre-clinical models of renal disease, these imaging techniques could be effective tools for elucidating pathological mechanisms of obstructive kidney disease.

Tanja Gaa¹, Frank Zoellner¹, Florian Lietzmann¹, and Lothar Schad^1
1Medical Faculty Mannheim, Heidelberg University, Computer Assisted Clinical Medicine, Mannheim, Germany

High PAT (Parallel Acquisition Technique) factors were used to reduce the acquisition time and also to receive a good image and fit quality for 3D BOLD imaging of the human kidney. The measurement delivers constant R₂* values (medulla: 42.7 to 44.7 1/s, cortex: 22.7 to 24.6 1/s). The fit quality of the R² fit does not change with higher PAT factors as well (medulla: 0.95 to 0.98, cortex: 0.93 to 0.95). The acquisition time and therefore, the breathhold time for the patient could be reduced from 40 seconds for PAT 1 to 15 seconds for PAT 6.

Lu-Ping Li¹, Hongyan Du², Tammy Franklin¹, Ujala Bokhary¹, Maria Papadopoulou-Rosenzweig³, Richard Solomon⁴, and Pottumarthi V Prasad^1
1Radiology Dept., Northshore University Healthsystem, Evanston, IL, United States, ²Center for Clinical & Research Informatics, Northshore University Healthsystem, Evanston, IL, United States, ³Radiation Oncology, Northshore University Healthsystem, Evanston, IL, United States, ⁴Medicine, Fletcher Allen Health Care, Burlington, VT, United States

Radio-contrast induced nephropathy (CIN) is the 3rd common cause of in-hospital mortality in patients with pre-existing kidney insufficiency. Physico-chemical properties of the contrast media are known to influence their risk profile. Renal hypoxia is known to play a role in the pathophysiology of CIN and BOLD MRI has been shown to be useful in monitoring the changes in intra-renal oxygenation following administration several pharmacological agents including radio-contrast media. Here, we report for the first time, a direct comparison among four radio-contrast agents with different physic-chemical properties (monomer/dimer, iconicity, osmolality, viscosity) using BOLD MRI.

Benjamin Dickie¹, Constantina Chrysochou², Su Wei Lim¹, Philip A Kalra², David L Buckley¹, and Steven Sourbron^1
1Division of Medical Physics, University of Leeds, Leeds, Yorkshire, United Kingdom, ²Department of Renal Medicine, Salford Royal Hospital, Manchester, United Kingdom

The aim of this study was to identify the reason for the bias in single-kidney glomerular filtration rate (SK-GFR) derived from a two-compartment filtration model. Three hypotheses were investigated: (I) water reabsorption is modelled incorrectly; (II) the model is not suitable for whole-kidney curves; (III) the tubuli are not well-mixed. 64 kidneys with known Isotope SK-GFR served as a basis for comparison. The results show that hypothesis (III) explains the bias. Assuming instead a plug-flow model for the tubulus eliminates the bias and increases the precision, without compromising the quality of the fit or increasing the number of free parameters.

Eito Kozawa¹, Tsutomu Inoue², Waka Mizukoshi³, Naoko Nishi⁴, Hiromichi Suzuki², and Fumiko Kimura^3
1Imaging Diagnosis, Saitama Medical University, International Medical Center, Hidaka-shi, Saitama, Japan, ²Nephrology, Saitama Medical University, Japan, ³Imaging Diagnosis, Saitama Medical University, International Medical Center, Japan, ⁴Saitama Medical University, International Medical Center, Japan

Functional renal MRI techniques together over morphological criteria can improve MRI specificity.

Masahiro Horikawa¹, Hiroshi Shinmoto¹, Akio Horiguchi², Shigeyoshi Soga¹, Eisuke Shiomi¹, Shigeru Kosuda¹, and Tatsumi Kaji^1
1Radiology, National Defense Medical College, Tokorozawa, Saitama, Japan, ²Urology, National Defense Medical College, Tokorozawa, Saitama, Japan

Urethral injury occurs as a result of trauma or iatrogenic cause. Retrograde urethrography is a gold standard to evaluate disruption of involved urethra, however, MR imaging has been reported to be useful to assess the extent of injury and presence of hematoma or fibrosis. The purpose of this exhibit is to demonstrate various patterns of urethral injury and to show the advantage of MR imaging in perioperative management thorough case presentations, ranged from common blunt trauma to rare condition such as urethrocutaneous fistula after sex transformation surgery.

Thomas A. Hope¹, Philip LeBoit², Whitney A. High³, Yanjun Fu⁴, and Robert C. Brasch^4
1Radiology and Biomedical Imaging, UCSF, San Francisco, CA, United States, ²Dermatology, UCSF, San Francisco, CA, ³Dermatology, University of Colorado, Denver, CO, ⁴Radiology, UCSF, San Francisco, CA

We have evaluated the efficacy of imatinib mesylate for the treatment of nephrogenic systemic fibrosis in a high dose GBCA animal model and have demonstrated that the administration of imatinib results in decreased lesion severity suggesting that imatinib may be effective in the treatment of NSF in humans.

Jeffrey Harold Maki^1,2, Gregory J Wilson³, Miles A Kirchin⁴, Sarah Bastawrous², and Puneet Bhargava^2
1Radiology, University of Washington, Seattle, WA, United States, ²Radiology, Puget Sound VAHCS, Seattle, WA, United States, ³MR Clinical Science, Philips Medical, Cleveland, OH, United States, ⁴Medical Affairs, Bracco Diagnostics, Milan, Italy

High-relaxivity protein-binding contrast agents are believed to improve contrast-enhanced MRA. To effectively use these agents, knowing their true r1 and r2 relaxivities in human blood at MRA concentrations is vital. In vitro relaxivity measurements (gadoteridol, gadobenate, gadofosveset) were performed in human blood at concentrations to 20 mmol (1.5, 3T). R1 and R2* were non-linear vs. [Gd] such that relaxivities r1 and r2* depended highly on [Gd]. At low concentrations r1 relaxivity behaved approximately per labeling data, but >3mmol the r1 of all agents decreased and became similar. This and r2* effects suggest higher Gd doses may be detrimental for CE-MRA.

Wenlong Xu¹, Krishna Kattel¹, Ja Young Park¹, Badrul Alam Bony¹, Woo Choul Heo¹, Tirusew Tegafaw Mengesha¹, and Gang Ho Lee^1
1Department of chemistry, Kyungpook National University, Daegu, Korea

The single-phase mixed ultrasmall GdEuO₃ nanoparticles are potential candidates for dual imaging experiment.It emerges as a new and advanced imaging technique in clinical applications. It is expected that it will play a key role to diagnose diseases by replacing conventional single-imaging techniques. We developed a simple one-step synthesis of lactobionic acid surface-modified ultra small GdEuO₃ nanoparticles. It was well characterized by using MP-XRD, TEM, FT-IR spectrophotometer, TGA, confocal microscope, SQUID magnetometer and Magnetic Resonance Imaging (MRI) instrument.

Yuki Mori¹, Punniyakoti Thanikachalam Veeraveedu², Yutaka Komai², and Yoshichika Yoshioka^1
1Biofunctional Imaging, WPI IFReC, Osaka University, Suita, Osaka, Japan, ²Single Molecule Imaging, WPI IFReC, Osaka University

This study investigated to visualize the lymphatic structures of healthy mice on high-resolution three-dimensional manganese–enhanced MRI (3D-MEMRI) at 11.7 T. Furthermore, we try to discriminate lymphatic vessels from blood streams with double contrast agents administration of interstitial manganese chloride solution (MnCl₂) as a positive contrast agent for lymphatic vessels and intravenous micron-sized particles of iron oxide (MPIOs) as negative contrast for vein, respectively. Interstitial administration of MnCl₂ resulted in a fast and high accumulation in lymph nodes and depicted lymphatic vessels clearly. In addition, simultaneous administration of interstitial MnCl₂ and intravenous MPIOs discriminated lymphatic vessels from blood vessels.

BADRUL ALAM BONY¹, Ja Young Park², Krishna Kattel³, Wenlong Xu³, Woo Choul Heo³, Tirusew Tegafaw Mengesha³, and Gang Ho Lee^3
1Chemistry, Kyungpook National University, Daegu, Korea, ²Kyungpook National University, Kazakhstan, ³Kyungpook National University

We have developed ultra-small gadolinium oxide nanoparticles, which are surface-doped with manganese oxide abbreviated as Gd2O3@MnO. In this work, the surface doped gadolinium oxide nanoparticles with an average d of 1 to 2 nm, which can be dispersed homogeneously. They were further coated with hydrophilic biocompatible lactobionic acid. It shows high relaxivity than normal ultrasmall gadolinium oxide nanoparticle. In-vitro tests of the sample solution indicated clear dose-dependent contrast enhancements in both T1 and T2 map images, showing that the nanoparticles may be used as both T1 and T2 MRI contrast agents.

Jiangsheng Yu¹, Xia Zhao¹, Yiqun Xue¹, Mark A Rosen¹, Christina S Chu², and Hee Kwon Song^1
1Departments of Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, PA, United States

The goal of this work is to determine to what extent flip angle deviations affect DCE-MRI perfusion parameter accuracy on three different MRI systems, including whether higher fields and short bore systems can potentially exacerbate these measurement inaccuracies. The results show that over a large region of the body, the ranges of flip angle deviations are similar for the three systems. These variations can potentially mask true changes in tumor treatment response, and flip angle mapping may be a crucial in DCE-MRI protocols.

Woo Choul Heo¹, Ja Young Park¹, Kattel Krishna¹, Wenlolg Xu¹, Tirusew Tegafaw Mengesha¹, Badrul Alam Bony¹, and Gang Ho Lee^1
1Department of Chemistry, Kyungpook National University, Daegu, Korea

We reported the synthesis and characterization of ultrasmall gadolinium oxide nanoparticles. In this work, the ultrasmall gadolinium oxide nanoparticles with an average d of 1 nm having r1 of 9.9 s-1 mM-1, which is much larger than those of Gd(III)-chelates. It seems that surface Gd(III) ions in gadolinium oxide nanoparticles cooperatively induce the longitudinal relaxation of the water proton. As a result, this cooperative induction effect accelerates the longitudinal relaxation of the water proton, providing a larger r1 than Gd(III)-chelates. We address this by carefully examining the d dependence of r1. We finally took in vivo T1 MR images of a rat with a brain tumor by using D-glucuronic acid coated ultrasmall gadolinium oxide nanoparticles and observed a clear contrast enhancement in T1 MR images of the tumor after injection.

Lijia Wang¹, Thanh D. Nguyen², Mengchao Pei^2,3, Jianqi Li³, and Yi Wang^2,3
1Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, Shanghai, China, ²Weill Cornell Medical College, New York, NY, United States, ³Shanghai Key Laboratory of Magnetic Resonance,East China Normal University, Shanghai, Shanghai, China

A fully automated software-based T1 and T2 measurement method is proposed for phantom studies to shorten processing time and improve reproducibility. This method was validated on phantom data acquired from 77 doped water samples by comparing with manual measurements. Excellent T1 and T2 agreement was found between the two methods, while the processing time was reduced by thousands of times by the automated method

Catherine Mallik¹, Steve Bandula², Scott Rice², David Atkinson², Stuart Taylor², James Moon³, and Shonit Punwani^2
1Centre for Medical Image Computing, University College London, London, United Kingdom, ²UCL Centre for Medical Imaging, University College London Hospital, United Kingdom, ³Imaging Centre, The Heart Hospital, University College London Hospital, London

Changes in the fractional volume of the extravascular, extracellular space (VEES) can be indicative of pathology. Equilibrium MRI (EQ-MRI) is a recently proposed technique to measure VEES, provided a constant concentration is reached between the contrast agent in the blood pool and tissue of interest. A pharmacokinetic model of a bolus and infusion protocol was devised to predict an optimal infusion rate and the time when equilibrium would be reached over a range of Ktrans values incorporating both diseased and healthy tissue. Pilot data collected in a control is indicative that equilibrium was reached in normal liver and muscle tissue.

Ja Young Park¹, Krishna Kattel¹, Wenlong Xu¹, Badrul Alam Bony¹, Woo Choul Heo¹, Tirusew Tegafaw Mengesha¹, and Gang Ho Lee^1
1Department of Chemistry, Kyungpook National University, Daegu, Korea

The present work deals with bimodal imaging agent which emerges as new and efficient imaging techniques in clinical applications. D-glucuronic acid surface-coated ultra-small gadolinium iodate nanoparticles have been synthesized and well characterized. It may be used for both MRI contrast agent and CT contrast agent. Finally, we took in vivo T1 MR images and CT images of a rat with a brain tumor by using D-glucuronic acid coated ultrasmall gadolinium iodate nanoparticles. We observed a clear contrast enhancement in MR images and CT images of the tumor after injection of nanocolloid.

Shahid M Hussain¹, Jeremy Van Tilburg², Mariah Smith-Miloff¹, and Thomas G. Perkins^3
1Department of Radiology, University of Nebraska Medical Center, Omaha, NE, United States, ²The Nebraska Medical Center, United States, ³Philips Healthcare, Cleveland, OH, United States

Compared to abdominal CT, current liver MRI exams are relatively long (often approx. 30 minutes vs. <5 min for CT). The introduction of 3.0T with higher SNR, phased array coils, parallel imaging techniques, and novel sequences allow us to perform real-time scanning and reconstruction. Decreasing imaging time should affect patient compliance and result in a more economic use of MRI machines, while providing a time-competitive alternative to CT examinations. Our results show that a 10-minutes comprehensive liver MRI protocol at 3.0T is feasible by the application of novel breath-hold sequences and a simultaneous scanning and reconstruction algorithm.

Tomoe Barr¹, Phillip Kuo², Judith Pugh³, Charmi Patel³, Horacio Rilo⁴, Scott Squire², Thomas Boyer⁵, and Maria I Altbach^2
1Biomedical Engineering, University of Arizona, Tucson, AZ, United States, ²Radiology, University of Arizona, United States, ³Pathology, University of Arizona, United States, ⁴Surgery, University of Arizona, United States, ⁵Medicine, University of Arizona, United States

Chronic liver disease due to Hepatitis B/C infection or non-alcoholic steatohepatitis (NASH) is a major health problem in the USA and worldwide. The diagnosis of these pathologies requires a liver biopsy which is an invasive procedure with associated morbidity and cost and subject to sampling errors. Thus non-invasive imaging methods are actively being sought. In this work we use a novel radial gradient and spin-echo (RADGRASE) method which provides T2 of the water component and fat fraction maps from data acquired in a breath hold. These parameters are used to characterize changes in the liver due to inflammation, fibrosis, and steatosis in subjects with suspected of chronic liver disease.

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

In this study on 30 volunteers, fat (considered a risk factor for some diseases) assessed using MRI, Dual Energy X-ray Absorptiometry (DEXA) and Bio-impedance analysis (BIA) are compared and correlated. The results indicate the following : MRI evaluated abdominal fat correlated well with trunk fat (DEXA) and body fat (BIA); good correlation between measurements in thigh region (MRI) and legs (DEXA); while abdominal fat is an indicator of body fat, that from the thigh region is not. The three techniques can be used interchangeably for estimating abdominal fat but MRI has the additional advantage of giving information on fat distribution.

Houchun Harry Hu^1,2, Daniel Larry Smith, Jr.³, Yongbin Yang³, Guihua Zhai⁴, and Tim R. Nagy^3
1Radiology, Children's Hospital of Los Angeles, Los Angeles, California, United States, ²Electrical Engineering, University of Southern California, Los Angeles, California, United States, ³Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States, ⁴Radiology, University of Alabama at Birmingham, Birmingham, Alabama, United States

Brown adipose tissue (BAT) is involved in non-shivering thermogenesis. When stimulated, it metabolizes its fat stores to produce heat and maintain body temperature. We utilize chemical-shift MRI at 9.4T to measure BAT fat content in 3 groups of mice (n=16/group) that were singly housed at 16-cold, 23-room, and 30-warm degrees Celsius over four weeks. We demonstrate that BAT fat-signal fraction measured at week 4 is positively correlated with housing temperature (cold-50.4±8.0%, room-60.8±11.9%, hot-79.4±12.1%) and significantly different between groups (p<0.01). Results demonstrate the differential thermal demand of animals in each group and prove that chemical-shift MRI can reflect BAT activity in vivo.

Shenghong Ju¹, Xin-gui Peng¹, and Gao-jun Teng^1
1Department of Radiology, Zhongda Hospital, Southeast University, Nanjing, Jiangsu, China

To study the feasibility of in vivo MR measurement of lipid accumulation and oxygenation in kidney using the diabete (db/db) mouse model

Patricia Maria Nunes¹, Alan James Wright¹, Cees Tack², and Arend Heerschap^1
1Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands, ²Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, Gelderland, Netherlands

A mouse-scale 13C MRS method was developed, to enable the evaluation of knockout mice in vivo for skeletal-muscle substrate oxidation at the level of TCA cycle. [2-13C]acetate or [2,4,6,8-13C]octanoate was infused and yielded sufficient 13C labelling in glutamate C4/C2. Half-maximal 13C enrichments during acetate and octanoate infusion were respectively, 7.2±1.8min and 30.7±4.2min for glutamate C4, and for glutamate C2 19.9±3.9min and 38.3±11.8min. Relative anaplerotic contribution for TCA-cycle flux were similar in both acetate and octanoate infusions with 0.40±0.10 and 0.42±0.20. This study shows the feasibility of 13C MRS to compare in vivo fatty-acid oxidation and TCA-cycle kinetics in mouse’ skeletal-muscle.

Andrew Louis Wentland^1,2, Nancy K Sweitzer³, Oliver Wieben¹, Elizabeth A Sadowski², Thomas M Grist², and Chris J Francois^2
1Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States, ²Radiology, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States, ³Medicine, University of Wisconsin School of Medicine & Public Health, Madison, WI, United States

It is hypothesized that arterial stiffening in patients with metabolic syndrome (MS) will lead to elevated aortic pulsatility and subsequent renal barotrauma. The purpose of this study was to assess aortic stiffness and renal oxygen bioavailability in MS patients using MR-based pulse wave velocity (PWV) and BOLD techniques. PWV and medullary oxygen bioavailability were significantly greater in MS patients than in healthy volunteers. The association of increased PWV and altered renal tissue oxygenation, as well as the known increase in renal dysfunction with advanced MS, suggests that arterial stiffening may play a causal role in renal dysfunction and future risk.

Christopher J François¹, Valentina Taviani², Jennifer L Rehm³, Christopher J Hardy⁴, Ellen L Connor³, and Scott B Reeder^1,2
1Radiology, University of Wisconsin, Madison, WI, United States, ²Medical Physics, University of Wisconsin, Madison, WI, United States, ³Pediatrics, University of Wisconsin, Madison, WI, United States, ⁴GE Global Research, General Electric, Niskayuna, NY, United States

Vascular stiffness is one of the earliest predictors of future cardiovascular disease (CVD). However, it is incompletely understood how various risk factors for CVD lead to vascular stiffening. Emerging evidence suggests that hepatic steatosis may play an important role in the development of CVD in adults. In this study we demonstrate the feasibility of assessing pulse wave velocity (PWV), a well established bio marker of vascular stiffness, hepatic fat fraction (HFF), visceral adipose tissue (VAT) and subcutaneous adipose tissue (SCAT) in adolescent girls with risk factors for metabolic syndrome.

Mangala Srinivas¹, Karolina Andralojc², Andor Veltien³, Maarten Brom², Leike Joosten², Arend Heerschap³, Jolanda de Vries¹, Carl Figdor¹, Otto Boerman², and Martin Gotthardt^2
1Tumor Immunology, RUNMC, Nijmegen, Gelderland, Netherlands, ²Nuclear Medicine, RUNMC, Nijmegen, Gelderland, Netherlands, ³Radiology, RUNMC, Nijmegen, Gelderland, Netherlands

Pancreatic islet transplant is a promising treatment for type I diabetes. However, islet survival and function is poor post-transplant. Here, we describe a non-emulsion based multimodal agent that is able to penetrate the membrane capsule around islets, and allows for quantitative in vivo 19F MRI, and fluorescence imaging. Labeling had minimal effects on viability and insulin secretion. We present preliminary imaging data in mice that received transplanted, labeled islets. Furthermore, islets remain detectable for at least two weeks post-transplant. Histology confirmed that the label is confined to the transplanted islets. The technique is potentially applicable to longterm, quantitative islet tracking.

Ronald Ouwerkerk¹, Ahmed Medhat Gharib¹, Monica Skarulis², and Roderic I Pettigrew^1,3
1Metabolic Imaging Branch, NIDDK/NIH, Bethesda, MD, United States, ²CLINICAL ENDOCRINE SECT, NIH/NIDDK, Bethesda, MD, United States,³NIH/NIBIB, Bethesda, MD, United States

Navigator gated single volume ¹H-MRS was used after B0 field mapping and manual shimming to obtain high quality liver spectra that allowed quantification of choline and glycogen, important metabolic markers in humans. Narrow line widths allowed more selective water suppression, avoiding saturation of glycogen. The T₂’s of glycogen, choline water and lipid were measured and used to estimate the absolute concentrations of metabolites. Average concentration of MRS visible choline compounds in eleven healthy volunteers was 16.9±4.5 mmol/kg ww; the concentration of glycogen glycosyl units was 78±36 mmol/kg ww. In-vivo measurement of liver choline and glycogen with ¹H-MRS can be an important tool for the study of metabolic disorders.

Cristóbal Martín Serrano García^1,2, Francisco Barrera³, Hugo Vidal⁴, Carlos Riquelme⁴, Pilar Labbé³, Jessica Liberona⁵, Marco Arrese³, Francisco Cruz⁴, Claudia Prieto^2,6, Pablo Irarrázaval^2,6, Cristián Tejos^2,6, and Sergio Uribe^2,4
1Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Región Metropolitana, Chile, ²Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Región Metropolitana, Chile, ³Gastroenterology, Pontificia Universidad Católica de Chile, Santiago, Región Metropolitana, Chile, ⁴Radiology, Pontificia Universidad Católica de Chile, Santiago, Región Metropolitana, Chile, ⁵Nutrition & Diabetes, Pontificia Universidad Católica de Chile, Santiago, Región Metropolitana, Chile, ⁶Electrical Engineering, Pontificia Universidad Católica de Chile, Santiago, Región Metropolitana, Chile

Intra abdominal fat depots has previously been associated with liver fibrosis on non alcoholic fatty liver disease (NAFLD) patients. In this study we evaluated different imaging biomarkers associated with liver fibrosis/cirrhosis in type 2 diabetes mellitus (DM2) patients. For this, we evaluated volumetric quantification of visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) using MR; volumetric quantification of abdominal fat depots with anthropometric indexes, like Body Mass Index (BMI) and Waist Circumference (WC); Transient Elastography (TrE) using Acoustic Radiation Force Impulse (ARFI), and clinical diagnosis based on different MR images. Results suggest that DM2 patients with increasing ARFI and largest amount of VAT might be associated with progression of liver fibrosis.

Jadegoud Yaligar¹, Venkatesh Gopalan¹, Shui Guanghou², Lam B D Jenny², Tai E Shyong³, Markus R Wenk², and S. Sendhil Velan^1
1Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Singapore, Singapore, ²Department of Biological Sciences, National University of Singapore, Singapore, Singapore, ³Department of Medicine, School of Medicine, National University of Singapore, Singapore, Singapore

Accumulation of Fatty acids and triglycerides in hepatocytes leads to metabolic syndrome. In the current study we have investigated the hepatic fat including saturated and unsaturation in high fat induced obese and control animals. In addition we have developed advanced LC/MS techniques for validating the MRS results. Both MRS and LC/MS results were comparable and increases the prior knowledge for MRS quantification. Total hepatic fat content estimated by MRS and LC/MS in high fat animals was significantly higher and unsaturation index was significantly lower compared to its control group. The combined approach of MRS and LC/MS techniques permits the comprehensive analysis of hepatic lipid components.

Houchun Harry Hu^1,2, Catherine D. G. Hines³, and Scott B. Reeder^4
1Radiology, Children's Hospital of Los Angeles, University of Southern California, Los Angeles, California, United States, ²Electrical Engineering, University of Southern California, Los Angeles, California, United States, ³Merck Research Laboratories, West Point, Pennsylvania, United States,⁴Radiology, Medical Physics, Biomedical Engineering, and Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States

We utilized a chemical-shift water-fat MRI technique to characterize T2* and proton density fat-fraction (PDFF) differences between interscapular brown (BAT) and gonadal white (WAT) adipose tissues in lean and genetically obese mice. Lean mice (n=6) and two groups of obese ob/ob mice placed on four-week (n=6) and eight-week (n=8) diets were studied. Comparing within each group, BAT T2* and PDFFs were consistently lower than WAT (p<0.001). Comparing across groups, longer BAT T2* and greater BAT PDFFs were measured in older and more obese ob/ob mice than lean mice (p<0.001). Collectively, these observations reflect the lean group’s greater BAT thermogenic activity.

Steffen Renisch¹, Susanne Heinzer², Holger Eggers¹, Osman Ratib³, and Peter Börnert^1
1Philips Research Europe, Hamburg, Germany, ²Philips AG Healthcare, Zurich, Switzerland, ³Nuclear Medicine, University Hospital of Geneva, Geneva, Switzerland

The combination of PET and MR can increase the diagnostic value of both modalities due to the additional information becoming available. PET measures the spatial distribution of an appropriate tracer while MR offers a huge variety of soft tissue contrasts, like T1, T2 , diffusion and water and fat. For the latter Dixon imaging has been developed yielding excellent fat suppression and also clinically useful information about the fat distribution and its content in specific tissues [1]. Current literature shows [2] that there generally is limited 18F- Deoxyglucose (FDG) and 18F-Choline (FCH) [4] uptake in tissue with a high fat content. Therefore, the information about the fat content might be very useful in PET image interpretation. Integrated PET/MR platforms, now becoming available, enable the combination of anatomical information and information about the fat content from the Dixon images with the functional information stemming from the 18F-FDG- and 18FCH PET due to the intrinsic registration of PET and MR data. In this patient study, we demonstrate a correlation between fat void regions and FDG/FCH uptake. This information may serve for partial volume correction in PET reconstruction and permits further characterization of disease.

Thomas Kwee¹, Henriëtte Quarles van Ufford¹, Malou Vermoolen¹, Frederik Beek¹, Rob Fijnheer², Willem Mali¹, John de Klerk³, and Rutger-Jan Nievelstein^1
1Radiology, UMC Utrecht, Utrecht, Netherlands, ²Hematology, Meander MC, Amersfoort, Netherlands, ³Nuclear Medicine, Meander MC, Amersfoort, Netherlands

This study aimed to assess the correlation between the ADC and the FDG-PET/CT SUV in lymphoma. Although no correlation was found between the ADCmean and the SUVmax, there was a trend towards a mild negative correlation between the ADCmin and the SUVmax. This can be explained by the fact that the ADCmin better represents the area of lowest cellular density than the ADCmean; thus, lymphomas with higher cellularity tend to have higher glucose metabolism. Further studies are required to investigate the complementary roles of these DWI and FDG-PET/CT metrics with respect to tumor grading and assessment of response to therapy.

Matthew D Blackledge¹, Nina Tunariu¹, David J Collins¹, Martin O Leach¹, and Dow-Mu Koh^1
1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, United Kingdom

Whole body DWI (WBDWI) allows the duo quantification of the total diseased diffusion volume and associated global mean/ median apparent diffusion coefficient (ADC), which are promising response biomarkers. However, the interobserver agreement of this approach has not been previously established. We found excellent interobserver agreement for segmenting total diseased diffusion volume on WBDWI and very good interobserver agreement for global median ADC values. These quantitative indices are robust and could be investigated more widely in future clinical trials, especially for the assessment of metastatic bone disease.

Yoshimitsu Ohgiya¹, Jumpei Suyama¹, Syouei Sai¹, Makoto Saiki¹, Takashi Hashizume¹, Noritaka Seino¹, Masanori Hirose¹, and Takehiko Gokan^1
1Showa University School of Medicine, Tokyo, Japan

The purpose of this study was to evaluate the ability of DW MR imaging at 3.0T for diagnosing T stage in bladder cancer. Sensitivity and accuracy for differentiating T1 tumors from T2 to T4 tumors and Overall accuracy for diagnosing tumor stage obtained by using T2-weighted plus DW images were significantly better than those obtained by using T2-weighted images alone (P = 0.02). DW images at 3T can provide useful information for evaluating the T stage of bladder cancer, particularly in differentiating T1 or lower tumors from T2 or higher tumors.

Giuseppe Petralia¹, Josep Garcia-Bennett², Luke Bonello³, Stefano Viotti³, Paul Summers¹, Maria Giulia Zampino¹, Maria Cristina Leonardi¹, and Massimo Bellomi^1,3
1European Institute of Oncology, Milan, Italy, ²Hospital St Joan de Reus, Reus, Spain, ³University of Milan School of Radiology, Milan, Italy

Better long-term outcome is reported for rectal cancer patients with pathological complete response (pCR) after neoadjuvant chemoradiation therapy (NACRT). Minimalist approaches are a reasonable alternative to radical surgery in such patients, with equivalent outcomes. T2-weighted MRI is not predictive of pCR. Diffusion-weighted MRI (DW-MRI) detects abnormalities in tissues and there is preliminary evidence that the apparent diffusion coefficient (ADC) may predict response to therapy. Fifty-nine patients underwent DW-MRI before and after NACRT, and ADC was calculated for tumour. ADC values before and after NACRT and their changes following treatment did not predict the pCR after NACRT in rectal cancer patients.

Huyen Thanh Nguyen^1,2, Guang Jia¹, Zarine K Shah¹, Kamal S Pohar³, Amir Mortazavi⁴, Debra Zynger⁵, and Michael V Knopp^1
1Wright Center of Innovation in Biomedical Imaging, Department of Radiology, The Ohio State University, Columbus, OH, United States, ²Biophysics Program, The Ohio State University, Columbus, OH, United States, ³Department of Urology, The Ohio State University, Columbus, OH, United States,⁴Department of Internal Medicine, The Ohio State University, Columbus, OH, United States, ⁵Department of Pathology, The Ohio State University, Columbus, OH, United States

Purpose: to investigate the capability of 3T MRI in accurately staging bladder cancer. Methods: all scans were performed with T2w before DCE MRI. With defined staging criteria, a radiologist staged bladder tumors by using T2w images, and then DCE data. Results: staging of T2/lower by using T2w images and DCE data had high sensitivities (80% and 90%), specificities (82% and 73%), and accuracies (81% and 81%). The overall accuracy of staging with T2w and DCE MRI were 71% and 81%, respectively. Conclusion: 3T MRI with the potential to accurately stage bladder cancer can make a major impact on the patient outcome of cystectomy.

Alexandre Coimbra¹, Jill Fredrickson¹, Roel Funke¹, Daniel Chen¹, and Alex de Crespigny^1
1Oncology Early Clinical Development, Genentech, Inc., South San Francisco, CA, United States

Accurate assessment of tissue apparent diffusion coefficient (ADC) requires acquisition and analysis of multiple b-value diffusion weighted images (DWI). One important source of variability in this ADC assessment is spatial misregistration across the multiple DWIs, particularly those at high b-values. The current work describes a simple post-hoc automated approach for spatial registration of multiple b-value DWIs. Applied to test-retest data set from a cohort of cancer patients, this approach enhanced repeatability of ADC measurements.

Giuseppe Petralia¹, Sarah Alessi¹, Josep Garcia-Bennett², Paul Summers¹, Sara Raimondi¹, Roberto Di Filippi¹, Luke Bonello³, and Massimo Bellomi^1,3
1European Institute of Oncology, Milan, Italy, ²Hospital St Joan de Reus, Reus, Spain, ³School of Radiology University of Milan, Milan, Italy

Surgery is the best option for patients with advanced melanoma, who would benefit from early detection of metastases. Whole-body magnetic resonance imaging (WB-MRI) with diffusion weighted sequences was feasible on advanced melanoma patients. It was performed with low dose computed tomography (CT) of the lung every three months, allowing for a 30 fold reduction of radiation exposure, when compared to the radiation dose that the same patients would receive if followed-up with whole-body CT. The following overall sensitivity (93%), specificity (89%), negative predictive value (99%), positive predictive value (52%) and diagnostic accuracy (90%) were observed for the detection of metastases.

Moti Freiman¹, Jeannette M Perez-Rossello¹, Michael J Callahan¹, Mark Bittman¹, Stephan D Voss¹, Robert V Mulkern¹, and Simon K Warfield^1
1Radiology, Children's Hospital Boston/Harvard Medical School, Boston, MA, United States

Numerical schemes commonly used to estimate the Intra-voxel incoherent motion (IVIM) model parameters from DW-MRI approximate Rician noise of the signal intensities with a Gaussian noise model which may induce bias in IVIM model parameters estimation. We developed a maximum likelihood estimator (ML_R) that accounts for the Rician distributed noise; and assessed the impact of the noise model and numerical algorithm used to estimate IVIM model parameters. In vivo measurements of the abdominal organs’ IVIM model parameters values of 15 pediatric subjects show significant discrepancies of up to ~30% between ML_R and segmented least squares estimator, and smaller, but yet significant discrepancies of ~2%-3% between the non-linear least squares and ML_R estimators.

D J McHugh^1,2, P L Hubbard^1,2, S Zhao^1,2, G J Parker^1,2, and J H Naish^1,2
1Imaging Sciences and Biomedical Engineering, University of Manchester, Manchester, United Kingdom, ²The University of Manchester Biomedical Imaging Institute, United Kingdom

We present preliminary results of using pulsed and oscillating diffusion gradients at 1.5 T to measure the apparent diffusion coefficient (ADC) and perfusion-sensitive diffusivity as a function of effective diffusion time in the human liver. Results show an increase in ADC as shorter diffusion times are probed, providing evidence of restricted diffusion, as well as a decrease in the perfusion-sensitive diffusivity at shorter diffusion times. This indicates the feasibility of using the time-dependent diffusivity to distinguish between restricted diffusion and flow in humans, and the potential for using oscillating diffusion gradients at low field strength to reach shorter diffusion times.

Marc Eric Miquel^1,2, Andrew David Scott¹, Redha Boubertakh¹, Niall Dominic MacDougall¹, Nishat Bharwani³, and Andrea G Rockall^4
1Clinical Physics, Barts and the London NHS Trust, London, United Kingdom, ²Barts and the London Cardiovascular Biomedical Research Unit, Queen Mary University of London, London, England, United Kingdom, ³Radiology Department, Imperial College Healthcare NHS Trust, London, United Kingdom,⁴Department of Imaging, Barts and the London NHS Trust, London, United Kingdom

DW-MRI is potentially a useful cancer biomarker and apparent diffusion coefficient (ADC) could be used to monitor treatment. However, repeatability studies are still limited. We investigated the in-vitro and in-vivo repeatability of a free-breathing abdominal DWI-sequence. The in-vitro coefficient of variation was less than 1.5%. In-vivo, the coefficients of reproducibility were kidney 20%, gallbladder 21%, liver 24.7% and spleen 28.0% when taking into account small regions of interest.. For large volumes of interest, values fall to 7.7, 6.4, 8.6 and 9.6% respectively. If all organs are considered indiscriminately the values are 23.1% for small regions and 7.9% for large volumes.

Matthew D Blackledge¹, Dow-Mu Koh¹, Matthew R Orton¹, David J Collins¹, and Martin O Leach^1
1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, United Kingdom

A simple post-processing algorithm is described to correct for station mis-alignment and intra-station discontinuities in signal intensity in whole-body diffusion weighted imaging. The technique is demonstrated on a volunteer study and on a patient data set. A significant improvement in image quality compared to currently available correction methods is observed in both cases.

Nina Tunariu¹, David J Collins¹, Matthew Orton¹, James A d'Arcy¹, Veronica A Morgan¹, Sharon L Giles¹, and Nandita M deSouza^1
1CR-UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, London, United Kingdom

Diffusion Weighted MRI is considered a potential biomarker for anticancer therapy response. The literature suggests that assumption of a simple exponential relationship between signal attenuation and b value for ADC calculation may be too simplistic and that using more complicated mathematical models which account for the non-monoexponential behaviour of the diffusion signal attenuation in tissues results in a better data fitting and potentially less variable ADC estimates. The purpose of this study was to evaluate the influence of the mathematical model used to fit the DW-MRI data on the ADC values and their reproducibility.

Dan Xu¹, Gaohong Wu², Jun Xie², and Kenichi Kanda^2
1Applied Science Lab, GE Healthcare, Waukesha, WI, United States, ²MR Engineering, GE Healthcare, Waukesha, WI, United States

B0 field offset and eddy current induced image distortions often seen in diffusion weighted echo planar imaging can be worsened in multistation settings (e.g., whole body imaging), where the unmatched distortions at station boundaries can create sharp discontinuities, largely degrading image quality. We propose to use a combined high order eddy current and slice dependent center frequency correction to reduce image distortion and bulk shift. A 2-station phantom study shows that the proposed method is capable of minimizing station boundary discontinuities and slice shift trend.

Yeji Han¹, Yoojin Lee¹, ChangHyun Oh¹, and HyunWook Park^1
1Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea

Although whole-body DWI (wbDWI) is generally performed using the multistation approach, a recent work has demonstrated that the continuously moving table (CMT) approach produces images with more homogeneity in terms of temporal and spatial discontinuities. In the CMT-wbDWI, short tau inversion recovery (STIR) was used to suppress fat but remains of the fat signal could still be observed in the images. In this abstract, we propose to use the gradient reversal (GR) algorithm for CMT-wbDWI and analyze how the GR algorithm can improve the fat suppression results of the CMT sequences.

Peter Gibbs¹, Martin D Pickles¹, and Lindsay W Turnbull^1
1University of Hull, Hull, East Yorkshire, United Kingdom

Bi-exponential fitting of DWI data to account for microperfusion effects is becoming increasingly prevalent both in the brain and other organs. Increased sampling of low b-values to adequately define the bi-exponential curve appears necessary. However, little work has attempted to assess the optimum b-value sampling strategy. Using synthetic data this study demonstrates that a highly non-linear sampling scheme is necessary for tissues with a rapid and large perfusive component and that high SNR data is required to appropriately define tissues with a small perfusive fraction.

Hayato Takano¹, Tomohiko Horie¹, Isao Muro¹, Nao Kajihara¹, Yutaka Imai¹, Makoto Obara², Tetsuo Ogino², Akira Suwa², Marc van Cauteren², Gwenael Herigault², Thomas Kwee³, and Taro Takahara^4
1Radiology, Tokai University School of Medicine, Isehara, Kanagawa, Japan, ²Philips Healthcare, ³University Medical Center Utrecht, ⁴Tokai University School of Engineering, Hiratsuka, Kanagawa, Japan

 

ZHIQIANG LI¹, Zhenghui Zhang¹, Gaohong Wu¹, and Xiaoli Zhao^1
1MR Engineering, GE Healthcare, Waukesha, WI, United States

One issue with single-shot diffusion-weighted EPI image of the liver is the signal loss in regions proximal to the heart due to cardiac motion. Various techniques in both data acquisition and post-processing have been proposed to mitigate this issue. In this work we present a new post-processing strategy to reduce the signal loss by combining the individual diffusion-weighted images with appropriate weights. In-vivo results demonstrated the feasibility.

Masanori Ozaki^1,2, Yusuke Inoue³, Tosiaki Miyati², Hirofumi Hata⁴, Shinya Mizukami⁵, Shotaro Komi⁴, Keiji Matsunaga³, Reiko Woodhams³, and Shinichi Kan^3
1School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa, Japan, ²Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, Japan, ³Department of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan, ⁴Department of Radiology, Kitasato University Hospital, Kanagawa, Japan, ⁵Department of Radiology, Kitasato University Hospital, Sagamihara, Kanagawa, Japan

In diffusion-weighted imaging (DWI), the artificial elevation of the apparent diffusion coefficient (ADC) of the liver parenchyma occurs due to signal loss caused by cardiac motion. This effect can be reduced by using a velocity-compensated (VC) -DWI sequence. However, a limitation of the VC-DWI sequence is that it provides a lower SNR than a conventional DWI sequence. Tetrahedral gradients can be used to obtain higher SNRs than conventional orthogonal gradients. The purpose of our study was to evaluate the efficacy of a VC-DWI sequence combined with tetrahedral gradients (t-VC-DWI) in liver parenchyma.

Yuriko Suzuki¹, and Marc Van Cauteren^1
1MR Clinical Science, Philips Electronics Japan, Minato-ku, Tokyo, Japan

Diffusion Kurtosis Imaging (DKI) is a method to study the deviation of water diffusion from Gaussian distribution, which has been applied mostly to study neural tissue characterization and brain diseases. The aim of study was to investigate how the selection of maximum and minimum b-value affected the liver DKI analysis, and to assess the feasibility of liver DKI in reasonable scan time. Our study has shown relatively good results even with maximum b-value of 1,500 s/mm2, which is smaller than one used in the brain, and would make easier to apply clinical cases.

Hongyan Chen¹, Yufang Chen¹, He Wang², Yongbo Yang¹, Guang Cao², and Xu Yan^3
1Eastern Hepatobiliary Surgery Hospital, Shanghai, Shanghai, China, ²Applied Science Lab, GE Healthcare, Shanghai, Shanghai, China, ³East China Normal University, Shanghai, Shanghai, China

This study is a preliminary trial of evaluating treatment response of liver carcinoma based on FDM. 20 patients with liver carcinoma were enrolled in our research. Our results shows the percentage of the increased ADC region and changed ADC region can be robust imaging biomarkers for detection of treatment response in patients with liver carcinoma.

Yukihisa Takayama¹, Akihiro Nishie¹, Yoshiki Asayama¹, Kousei Ishigami¹, Daisuke Kakihara², Yasuhiro Ushijima¹, Nobuhiro Fujita¹, Atsushi Takemura³, Makoto Obara³, and Hiroshi Honda^1
1Department of Clinical Radiology, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Fukuoka, Japan, ²Department of Molecular Imaging & Diagnosis, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Fukuoka, Japan, ³Philips Electronics Japan, Tokyo, Tokyo, Japan

Our proposed optimized diffusion-weighted imaging (DWI) can not only improve the image quality and spacial resolution, but also reduce chemical shift and susceptibility artifacts. In this study, we evaluated the utility of our proposed optimized DWI of liver magnetic resonance imaging. It can offer better diagnostic performance without reducing the signal-to-noise ratio of the normal liver parenchyma and lesion-to-non-lesion contrast-to-noise ratio with the conventional DWI which is widely used in the clinical practice. We suggest that our proposed optimized DWI should be advantageous for liver MRI to detect hepatocellular carcinoma.

kyung Ah Kim¹, Mi-Suk Park¹, In-Seong Kim², Peter Gall³, Myeong-Jin Kim¹, and Ki Whang Kim^1
1Radiology, Yonsei University College of Medicine, Seoul, Seoul, Korea, ²MR Clinical Science, Siemens Healthcare, Korea, ³Oncology & Interventions, Siemens AG

 

Jeong-Hee Yoon¹, Jeong Min Lee², Olivier de Andre³, Mun young Paek³, MiHye Yu², Joon Ku Han², and Byung Ihn Choi^2
1Seoul National University Hospital, Seoul, Seoul, Korea, ²Seoul National University Hospital, ³Siemens Healthcare

Liver diffusion MR with intravoxel incoherent motion (IVIM) was performed using multiple b-values (b=0, 25, 50, 75, 100, 200, 500, 800) in 119 patients from June 2010 to May 2011. During the period, 29 patients underwent liver MR twice, and 9 out of 119 patients underwent liver diffusion MR in free breathing (FB) and respiratory triggering (RT). After obtaining IVIM derived parameters, we assess the difference between parameters in FB and those in RT. Also we assessed the reproducibility of IVIM derived parameters. Finally IVIM derived parameters were compared in liver cirrhosis group and non-cirrhotic group.

Raj Attariwala¹, and Wayne Picker^1
1AIM Medical Imaging, Vancouver, BC, Canada

An overview of the theory of diffusion weighted imaging, and adding this powerful sequence routinely into whole body MRI imaging for improved lesion localization and characterization will be reviewed. Incorporation of diffusion images and critical parameters for ADC calculation as well as interpretation pearls and pitfalls will be presented from a facility that has performed over 1000 diffusion studies.

Tomohiro Namimoto¹, Toshinori Hirai¹, Kosuke Morita¹, Daisuke Utsunomiya¹, Seitaro Oda¹, Fumi Sakaguchi¹, and Yasuyuki Yamashita^1
1Diagnostic Radiology, Kumamoto University, Kumamoto, Kumamoto, Japan

The purpose of our study is to determine the accuracy of DW imaging in the characterization of ovarian masses with solid components and to clarify the relationship between ADCmean and ADCmin with solid components of the ovarian tumors in patients undergoing pelvic 3T MR imaging. In conclusion, the ADCmean and ADCmin of malignant ovarian masses with solid components were significantly lower than those of other benign- and border line masses. ADCmin was better than ADCmean for characterization of ovarian masses with solid components. However, it may be occasionally difficult to differentiate benign and malignant masses only on the basis of DW imaging.

Peter Stanwell¹, Jonathan Carter², Peter Russell³, and Carolyn Mountford^4
1Faculty of Health, University of Newcastle, Callaghan, NSW, Australia, ²Royal Prince Alfred Hospital, Sydney Gynaecological Oncology Group, Camperdown, NSW, Australia, ³Sydney Gynaecological Oncology Group, Royal Prince Alfred Hospital, Camperdown, NSW, Australia, ⁴Centre for MR in Health, University of Newcastle, Callaghan, NSW, Australia

Single voxel spectroscopy (SVS) and apparent diffusion coefficients (ADC) were measured in 10 patients with clinical suspicion of ovarian cancer. Results from SVS and ADC were compared with histopathology obtained following surgery. Both techniques produced statistically significant differences for distinguishing between benign and malignant ovarian neoplasms. Further studies with larger patient numbers are now needed to validate this approach.

Chunmei Li¹, Min Chen², Luxian Zhang², Chen Zhang², and Cheng Zhou^2
1Beijing Hospital, Beijing, Beijing, China, ²Beijing Hospital

Purpose: To compare accuracy in the detection of recurrent ovarian cancer with DWI and T2WI on 1.5 T MR and determine whether imaging information can predict survival. Methods: Axial T2WI and DWI of 21 women were independently analyzed by two radiologists. Tumor presence, number of lesions, size and minimal ADC were recorded for patient and region. Receiver operator characteristic curves were generated. Results: Readers¡¯ AUCs in detection of recurrence were higher for DWI than for T2WI. Size, number ADC value were significantly associated with poor survival. Conclusion: DWI may improve accuracy in the detection and localization of recurrent ovarian cancer on 1.5 T MR. Some imaging findings can be used to predict survival.

Mayumi Takeuchi¹, Kenji Matsuzaki¹, and Masafumi Harada^1
1Department of Radiology, University of Tokushima, Tokushima, Tokushima, Japan

We evaluated ovarian solid, or complex solid and cystic masses by MRS at 3T. The choline concentration in 21 malignant tumors with predominantly solid nature (9.47 +/- 4.66 mM) was significantly higher than that in 11 benign lesions (5.48+/-4.77 mM) (p<0.05). Using a cut off value of 6 mM for malignant lesions had a sensitivity of 81%, specificity of 73%, PPV of 85%, and NPV of 67%. MRS can provide helpful information in distinguishing benign and malignant ovarian tumors, however, malignant tumors showing solid and cystic nature or containing necrotic areas tended to show lower choline concentration.

Xiaoduo Yu¹, Yan Chen¹, Meng Lin¹, Han Ouyang¹, and Chunwu Zhou^1
1Department of Diagnostic Radiology, Cancer Hospital & Institute, Chinese Academy of Medical Sciences & Peking Union Medical College, beijing, beijing, China

MRS could provide insights into the metabolism of uterus tumor at molecular level, and has the utility to evaluate the state of endometrium in physiology and pathology quantitatively. Difference among choline peak value of endometrial carcinoma and normal endometrium of childbearing women in different menstrual cycle would be helpful to diagnose the endometrial carcinoma and optimization of exam time.

Mayumi Takeuchi¹, Kenji Matsuzaki¹, and Masafumi Harada^1
1Department of Radiology, University of Tokushima, Tokushima, Tokushima, Japan

We evaluated 14 uterine sarcomas and 24 benign myometrial lesions by 1H-MR spectroscopy at 3T. High lipid peaks were observed in 12 of 14 sarcomas, whereas in none of benign lesions except for one lipoleiomyoma. The choline peaks were observed in 12 of 14 sarcomas, whereas in all 24 benign lesions. However massive necrosis in sarcomas may decrease the choline peak, the presence of high lipid peak may suggest their malignant nature. We conclude that high lipid peak in uterine mass without fatty component is suggestive for sarcoma, whether the choline peak is present or not.

Zhengyang Zhou¹, Haiping Yu¹, Bin Zhu¹, Ying Hong², and Jiang Fang^2
1Radiology, Affiliated Drum Tower Hospital,School of Medicine,Nanjing University, Nanjing, Jiangsu, China, ²Gynaecology, Affiliated Drum Tower Hospital,School of Medicine,Nanjing University, Nanjing, Jiangsu, China

To evaluate whether combined DWI and MR lymphography (MRLG) reliably detect and evaluate sentinel lymph nodes (SLNS) metastasis in cervical cancer, 38 patients were preoperatively underwent interstitial MRLG with Omniscan after completed the conventional MRI and DWI examinations at a b-value of 1000 s/mm2. Blue dye SLN biopsy was performed on all patients. We found that compared with only MRLG without DWI versus histopathology, the combined MRLG and DWI approach revealed a higher diagnostic accuracy. Obviously, the combination of DWI and MRLG was useful in detecting the SLNs and in improving the diagnostic accuracy of SLN metastases in cervical cancer.

Martine I Dujardin¹, Martin D Pickles¹, Abdullah Aldosary², Peter Gibbs¹, and Lindsay W Turnbull^1
1Centre for MR Investigations, University of Hull in association with Hull York Medical School, Hull, United Kingdom, ²King Fahad Medical City, Riyadh, Saudi Arabia

This study investigates the ability of pretreatment ADCs acquired at 3T to predict overall survival (OS) in chemoradiotherapy in advanced cervical cancer patients (N=26). The use of group median (p=0.16 ) or 75th percentile of group ADC values (p=0.86) as a dichotomizing value did not result in a significant difference for survival between a high and low ADC group. Kaplan-Meier analysis showed that the survival rate in the low-ADC group was significantly worse than that in the high-ADC value group (p=0.042) when groups were dichotomized on the basis of the 25th percentile (0.85×10-3 mm2/s) of group pretreatment ADC values.

Søren Haack¹, Erik Morre Pedersen², Mads Sloth Vinding³, Jesper Folsted Kallehauge⁴, Jacob Christian Lindegaard⁵, Kari Tanderup⁵, and Sune Nørhøj Jespersen^6
1Dept. of Clinical Engineering, Aarhus University Hospital, Aarhus, Denmark, ²Dept. of Radiology, Aarhus University Hospital, Aarhus, Denmark, ³inSpin, iNANO, Aarhus University, Aarhus, Denmark, ⁴Dept. of Medical Physics, Aarhus University Hospital, Aarhus, Denmark, ⁵Dept. of Oncology, Aarhus University Hospital, Aarhus, Denmark, ⁶CFIN/Mindlab, Aarhus University, Aarhus, Denmark

Diffusion weighted MRI has shown great potential in diagnostic cancer imaging and may also have value for monitoring tumor response during radiotherapy. Uncertainties due to geometric distortions caused by B0-inhomogeneity and tumor delineation are major obstacles for implementing DWI for use in dose planning of radiotherapy. This study evaluates the use of k-means clustering for automatic user independent delineation of regions with reduced apparent diffusion coefficient (ADC) and the value of B0-correction of DW-MRI for reduction of geometrical distortions during dose planning of brachytherapy of advanced cervical cancer.

Mayumi Takeuchi¹, Kenji Matsuzaki¹, and Masafumi Harada^1
1Department of Radiology, University of Tokushima, Tokushima, Tokushima, Japan

We evaluated 14 extra-ovarian endometriosis by susceptibility-weighted imaging (SWI). In 12 solid tumor-like masses punctate or curved linear signal voids on SWI were observed in all lesions, whereas high intensity hemorrhagic foci on fat-saturated T1WI were observed in 7 of 12 lesions. In 2 cystic lesions curved linear signal voids along the cyst wall on SWI were observed, whereas high intensity hemorrhagic foci were not revealed on fat-saturated T1WI. We conclude that SWI is more sensitive for endometriosis-associated hemorrhagic change than fat-saturated T1WI, and may contribute to the diagnosis of extra-ovarian endometriosis.

Sung Bin Park^1
1Radiology, Cheil General Hospital & Women¡¯s Healthcare Center, Kwandong University College of Medicine, Seoul, Korea

The imaging characteristics of endometriosis vary widely, with masses ranging from cystic to solid and complex, which depend in the hormonal response of the ectopic tissue during the menstrual cycle. MRI is important for identification and characterization of endometriosis.

Sung Bin Park^1
1Radiology, Cheil General Hospital & Women¡¯s Healthcare Center, Kwandong University College of Medicine, Seoul, Korea

Pregnancy associated maternal disorders are broad spectrum. It is important to know this pregnancy associated maternal disorders because they may influence the fetus as well as the pregnant woman.

Takashige Yoshida¹, Yasutomo Katsumata², Yuki Furukawa¹, Naoki Watanbe¹, Yukio Kato¹, Nobuo Kawauchi¹, and Tetsuro Shirai^3
1Radioligy, Tokyo Metropolitan Police Hospital, Tokyo, Japan, ²Technical&Clinical Support, Philips Electronics Japan, Ltd., Tokyo, Japan, ³Tokyo Metropolitan Police Hospital, Tokyo, Japan

Three-Dimensional gradient echo sequence named THRIVE and e-THRIVE needs better contrast and lower artifact for pelvis image with Contrast enhacement. Adopted centric-radial k-space tarajectory as THRIVE result in good contrast,but blurring is outstanding. And adopted linear k-space trajectory combined partial Fourier transformation as e-THRIVE improved blurring of THRIVE, but truncation influences image using e-THIRVE.Furthermore,adopted linear radial k-space trajectory as Liner-THRIVE was able to improve disadvantage of THRIVE and e-THRIVE.

RAJ MOHAN PASPULATI¹, Kianoush.Ansari Gilani¹, and GURUPREET SANDHU^2
1RADIOLOGY, UNIVERSITY HOSPITALS, CASE WESTERN RESERVE UNIVERSITY, CLEVELAND, OHIO, United States, ²Radiology, University Hospitals, Case Western Reserve university, Cleveland, Ohio, United States

MR imaging of the female pelvis is performed routinely for diagnosis of various benign uterine or adnexal pathology as well as for staging of gynecologic malignancies. Acquiring high resolution T2 weighted images in 3 orthogonal planes is the gold standard for evaluation of the complex pelvic anatomy and pathology. Traditional T2 weighted imaging includes acquiring high resolution 2D T2 Turbo spin echo (TSE) in 3 planes which is time consuming and image plane has to be prescribed according to the orientation of the uterus. Improper orientation of the imaging plane by the technologist results in loss of crucial anatomical information. Acquiring high resolution 3DT2 weighted images in a single plane significantly reduces scan time and is also less technologist dependent for selecting a proper imaging plane. Imaging technique, clinical utility, advantages and disadvantages of this T2 weighted imaging technique will be illustrated in this exhibit using several examples of benign and malignant pelvic pathology of the female pelvis.

Devasuda Anblagan¹, Ruta Deshpande², Nia W Jones², Alain Pitiot³, Carolyn Costigan¹, Kirsty Allcock⁴, Nick Raine Fenning⁵, Lopa Leach⁶, George Bugg², Peter Mansell², and Penny A Gowland^1
1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, ²Nottingham University Hospitals NHS Trust, United Kingdom, ³School of Psychology, University of Nottingham, United Kingdom, ⁴Medical Schools and Nursing Centres, University of Nottingham, United Kingdom, ⁵School of Clinical Sciences, University of Nottingham, United Kingdom, ⁶School of Biomedical Sciences, University of Nottingham, United Kingdom

Pregnancy complicated by diabetes often results in macrosomic infants (birth weight > 4000g). They are at increased risk of shoulder dystocia, brachial plexus injury, prolonged labor and caesarean section. The fetuses are at higher risk of becoming obese and developing Type 2 diabetes. We show significant increase in fetal fat volume, percentage fetal fat and fetal length but not total fetal volume at 33–37 weeks in diabetics compared to controls. In utero assessment of fetal size and fat distribution would allow clinicians to identify fetuses at risk of complicated delivery and study the metabolic changes in the infant.

Jin Yamamura¹, Björn Schoennagel², Chressen Much³, Roland Fischer^4,5, Gerhard Adam², and Ulrike Wedegaertner^2
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, ²Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Germany, ³Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, ⁴Pediatric Haematooncology, University Medical Center Hamburg-Eppendorf, Germany, ⁵Children's Hospital and Research Center Oakland, Oakland, California, United States

Antenatal liver and spleen iron quantification in a sheep model

Christopher D. Kroenke¹, Antonio E. Frias¹, Matthias C. Schabel¹, Peta L. Grigsby¹, Victoria H.J. Roberts¹, Kevin L. Grove¹, Karen Y. Oh¹, and Alina Tudorica^1
1Oregon Health & Science University, Portland, United States, United States

A method is described for quantifying maternal perfusion in the primate placenta using dynamic contrast enhanced MRI. In contrast to rodents, the primate placenta is organized into several 2-5 mL vascular structures termed cotyledons. We have characterized perfusion within the placental intervillous spaces of the macaque placenta at several stages of pregnancy by analyzing contrast reagent arrival time as a function of distance from spiral artery inputs. As a result, intervillous blood flow is quantified for each cotyledon. Substantial heterogeneity in blood flow is observed between cotyledons and between individual subjects, indicating the potential of this analysis for assessing placental function.

David Alberg Peters¹, Anne Sørensen², Ernst-Torben Wilhelm Fründ³, Ole Bjarne Christiansen², and Niels Uldbjerg^4
1Department of Clinical Engineering, Central Denmark Region, Aarhus N, Denmark, ²Department of Gynecology and Obstetrics, Aarhus University, Aalborg Hospital, Aalborg, Denmark, ³Department of Radiology, Aarhus University, Aalborg Hospital, Aalborg, Denmark, ⁴Department of Gynecology and Obstetrics, Aarhus University Hospital, Skejby, Aarhus N, Denmark

MR is becoming more widely used for prenatal diagnosis, with the main focus being to detect structural changes in the fetus. Recently some groups have explored the use of functional MR in fetuses. These studies have mainly studied the effects in fetal organs in sheep. In this study we present a method for detecting the effects of oxygen breathing in placenta and the initial results from six healthy pregnant women. With further development this method could be used to evaluate placental function and determine the optimum time to deliver growth restricted fetuses.

Devasuda Anblagan¹, Ruta Deshpande², Nia W Jones², Carolyn Costigan¹, Caroline Wright³, David M Morris^4,5, Nick Raine Fenning⁶, Lopa Leach⁷, George Bugg², Peter Mansell², and Penny Gowland^1
1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, ²Nottingham University Hospitals NHS Trust, United Kingdom, ³Maternal and Fetal Health Research Group, University of Manchester, Manchester, United Kingdom, ⁴Imaging Sciences, University of Manchester, Manchester, United Kingdom, ⁵Biomedical Imaging Institute, University of Manchester, Manchester, United Kingdom,⁶School of Clinical Sciences, University of Nottingham, United Kingdom, ⁷School of Biomedical Sciences, University of Nottingham, United Kingdom

High volume, low resistance placental blood flow (f) is essential for optimal nutrient exchange. Aberrant placental blood flow is associated with conditions such as maternal diabetes, often resulting in areas with abnormal vascular development. This study is the first report of measurements of IVIM in the chorionic plate. The results show no change in f with gestational age, (consistent with previous results in basal plate and placenta). No significant changes were found in diabetes.

Yoshimitsu Ohgiya¹, Hiroshi Nobusawa², Jumpei Suyama¹, Syouei Sai¹, Makoto Saiki¹, Takashi Hashizume¹, Noritaka Seino¹, Masanori Hirose¹, and Takehiko Gokan^1
1Showa University School of Medicine, Tokyo, Japan, ²Kawasakisaiwai hospital, Kawasaki, Japan

The purpose of this study was to evaluate diminished flow voids on T2-weight RARE MR imaging of the placenta in fetuses with and fetuses without IUGR who were suspected of having placental infarction. The use of diminished flow voids in addition to morphologic signs increased sensitivity for the detection of placental infarction from 66.7% to 83.3%, increased accuracy from 81.5% to 86.8%, and preserved specificity at 90.0%. Evaluating flow voids on T2-weighted RARE images can be useful for detecting placental infarctions, particularly in placentas without morphologic signs on MR imaging.

Tom Roberts*^1,2, Francesca Norris*^1,2, Helen Carnaghan³, Jack Wells¹, Bernard Siow^1,4, Peter J Scambler¹, Agostino Pierro³, Simon Eaton³, and Mark Lythgoe^1
1UCL Centre for Advanced Biomedical Imaging, Division of Medicine and Institute of Child Health, University College London, London, United Kingdom,²Centre for Mathematics and Physics in Life Sciences & Experimental Biology (*Joint First Authors), University College London, London, United Kingdom,³Paediatric Surgery Unit, UCL Institute of Child Health, University College London, London, United Kingdom, ⁴Centre for Medical Image Computing, University College London, London, United Kingdom

Ex vivo MRI is a successful, non-invasive technique for studying disease development and gene function in mutant mouse models. However, there is currently no established method for assessing ex vivo embryos retained in the amniotic sac using MRI. Such a method would be valuable for determining the phenotypes of mutant embryos with abdominal wall defects such as gastroschisis and omphalocele, which are difficult to distinguish between using light microscopy. In this study, we developed a novel methodology to visualise "in amnio" embryos and successfully applied the technique to image a fetus with an omphalocoele defect.

Martyn NJ Paley¹, Michael Reeves¹, and Paul D Griffiths^1
1Academic Radiology, University of Sheffield, Sheffield, Yorkshire, United Kingdom

An MR compatible fetal electrocardiogram gating (fECG) system has been tested on pregnant female volunteers. Single shot Fast spin Echo images have been acquired gated to the fetal ECG although gradient pickup was detected during imaging sequences.

Tetsu Niwa¹, Koki Kusagiri¹, Yasuhiko Tachibana¹, Hiroshi Ishikawa², Tomoaki Nagaoka³, Kumiko Nozawa¹, and Noriko Aida^1
1Radiology, Kanagawa Childnren's Medical Center, Yokohama, Kanagawa, Japan, ²Obstetrics and Gynecology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan, ³National Institute of Information and Communications Technology, Koganei, Japan

Whole body fetal MRI at 3D-true-FISP

Tetsu Niwa¹, Noriko Aida¹, Yasuhiko Tachibana¹, Kumiko Nozawa¹, Tomoaki Nagaoka², and Hiroshi Ishikawa^3
1Radiology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan, ²EMC Group, National Institute of Information and Communications Technology, Koganei, Tokyo, Japan, ³Obstetrics and Gynecology, Kanagawa Children's Medical Center, Yokohama, Kanagawa, Japan

fetal lung to liver signal at true-FISP