ISMRM 21st Annual Meeting & Exhibition 20-26 April 2013 Salt Lake City, Utah, USA

Tuesday 23 April 2013
Room 155 EF  13:30 - 15:30 Moderators: Mustafa Shadi R. Bashir, Claude B. Sirlin

13:30 0274.   High Resolution Diffusion Weighted Imaging of Pancreatic Adenocarcinoma Using 2D Reduced Field of View Single-Shot Echo-Planar Imaging at 3.0 Tesla
Yan Li1, Chao Ma1, He Wang2, Shi Yue Chen1, and Jian Ping Lu1
1Department of Radiology, Changhai Hospital, The Second Military Medical University, Shanghai, China, 2MR Research China, GE Healthcare, Shanghai, China

Pancreatic cancer is one of the few cancers which have shown little improvement in survival over the past 30 years, with a 5-year survival rate of less than 5%. Combined with traditional MRI (such as T1WI, T2WI), Diffusion-weighed imaging (DWI) has showed high sensitivity and specificity in diagnosis of pancreatic cancer. We introduced a new way which may play a role in early diagnosis of pancreatic cancer, using DWI.

13:42 0275.   Precontrast T1-Weighted Hyperintense Nodules in Patients with Liver Cirrhosis: The Utility of Dynamic and Hepatobiliary Phases with Gadoxetate-Enhanced MRI.
Jing Luo1, Ka-kei Ngan1, Michael Nalesnik2, and Keyanoosh Hosseinzadeh1
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States, 2Pathology, University of Pittsburgh, Pittsburgh, PA, United States

Purpose: evaluate the utility of gadexotate-enhanced MRI for detecting HCC in patient with liver cirrhosis who have T1-weighted hyperintense lesions. Method: 31 nodules were evaluated. Diagnostic performance of dynamic vs. dynamic and HB phase, Cohen statistics for interobserver agreement, bootstrap resampling technique for comparing lesion size, and fisher exact test for correlation between HB phase and histology were performed. Conclusion: the addition of HB phase did not improve diagnostic performance; however, our data shows that nodules demonstrating both precontrast T1 hyperintensity and HB phase hypointensity are malignant and there is a statistically significant size difference between benign and malignant lesions.

13:54 0276.   
A Novel MRI Protocol to Examine Haemodynamic Compartments in Compensated Liver Cirrhosis
Eleanor F. Cox1, Antonella Ghezzi2, Andrea Bennet2, Mina Patel2, Andrew Jackson2, David Harman2, Carolyn Costigan1, Nur Farhayu Omar1, Martin W. James2, Stephen D. Ryder2, Penelope A. Gowland1, Guru P. Aithal2, I. Neil Guha2, and Susan T. Francis1
1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, 2NIHR Biomedical Research Unit in Gastrointestinal and Liver Diseases, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, Nottinghamshire, United Kingdom

The haemodynamics of four compartments (liver, splanchnic, cardiac and renal) are examined in a single scan session in early compensated cirrhosis (CC) patients and age matched healthy volunteers (HV) using phase contrast and arterial spin labelling in combination with cardiac MR. Patients with CC have lower perfusion in the liver and spleen compared with HV and increased splanchnic flow with vasodilation. Patients also have increased aortic outflow, left ventricular ejection fraction and cardiac output. The detection of these changes suggests the technique improves understanding of pathophysiology and has the potential as a tool to assess novel drug therapies.

14:06 0277.   Evaluation of Liver Fibrosis and Hepatic Venous Pressure Gradient with Magnetic Resonance Elastography in a Novel Swine Model of Cirrhosis.
Steven Y. Huang1, Samer Harmoush1, Mohamed E. Abdelsalam1, Joe Ensor2, Katherine Dixon1, Ken-Pin Hwang3, and Rony Avritscher1
1Dept of Diagnostic Radiology, University of Texas MD Anderson Cancer Center, Houston, Texas, United States, 2Dept of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas, United States, 3Dept of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, United States

In patients with cirrhosis, complications often arise from portal hypertension, which is an increase in the porto-systemic pressure gradient. The porto-systemic gradient is most commonly estimated by measuring the hepatic venous pressure gradient (HVPG). A large animal model of liver cirrhosis and portal hypertension is used to correlate liver stiffness measured by magnetic resonance elastography with HVPG. Significant correlations were observed between liver stiffness, hepatic fibrosis and HVPG. Our results corroborate the utility of MRE as a noninvasive method to measure liver fibrosis and HVPG while highlighting additional similarities between cirrhosis in humans and swine.

14:18 0278.   
MR Elastography of Liver with Iron Overload: Development, Evaluation and Preliminary Clinical Experience with Improved Spin Echo and Spin Echo EPI Sequences
Yogesh K. Mariappan1, Sudhakar K. Venkatesh1, Kevin J. Glaser1, Kiaran P. McGee1, and Richard Leroy Ehman1
1Department of Radiology, Mayo Clinic, Rochester, MN, United States

MR Elastography (MRE) is rapidly gaining clinical acceptance for the assessment of hepatic fibrosis. However, the standard gradient echo MRE technique can fail in cases with high iron deposition within the liver due to T2* signal loss. To address this issue, spin echo and spin echo EPI MRE pulse sequences with short TE values were developed and evaluated in subjects with and without iron overload. These sequences provided shear stiffness values comparable to the standard MRE sequence in unaffected subjects, and in patients with iron overload where the standard sequence failed, the spin echo approaches successfully provided valid shear stiffness maps.

14:30 0279.   Detection of Tissue Inflammatory Change with Multifrequency 3-D Magnetic Resonance Elastography
Meng Yin1, Kevin J. Glaser1, Jun Chen1, Yogesh K. Mariappan1, Jayant A. Talwalkar2, and Richard Leroy Ehman1
1Radiology, Mayo Clinic, Rochester, Minnesota, United States, 2Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, United States

To investigate the utility of MRE derived mechanical properties in detecting hepatic inflammation, we performed multifrequency 3-D/3-axis MRE technique on poroelastic phantoms and 87 patients with biopsy-proven chronic liver disease. Results demonstrated systematic variations in mechanical properties with increased interstitial fluid pressure, with delta (acrTan(G’’/G’)) the most promising. These findings offer preliminary evidence of the potential to extend MRE to distinguish and independently assess necroinflammatory and fibrotic processes.

14:42 0280.   
Assessing Liver Fibrosis: Comparison of Arterial Enhancement Fraction and Diffusion-Weighted Imaging -permission withheld
David Bonekamp1, Susanne Bonekamp1, Hsin-You Ou1, Michael S. Torbenson2, Celia Pamela Corona-Villalobos1, and Ihab R. Kamel1
1The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, United States, 2Department of Pathology, Johns Hopkins University, Baltimore, Maryland, United States

Arterial Enhancement Fraction (AEF) was compared to apparent diffusion coefficient (ADC) for assessment of hepatic fibrosis in chronic liver disease. Quantitative mapping of contrast enhanced MRI-derived AEF were used to grade fibrosis according METAVIR criteria. AEF and ADC values differed significantly between fibrosis stages. ROC analysis showed improved discrimination of fibrosis stages for AEF compared to ADC. AEF can be used for accurate noninvasive prediction of the presence of liver fibrosis stage, and its predictive value is increased with concomitant use of ADC in the form of a weighted composite score of AEF and ADC.

14:54 0281.   Distinction Between Pure Steatosis and NASH Using a Fat Quantification Method in Combination with Liver Intravoxel Incoherent Motion Imaging in MRI at 3.0 T.
Benjamin Leporq1, Frank Pilleul1,2, Jerome Dumortier3, Olivier Guillaud3, Thibaud Lefort3, and Olivier Beuf1
1CREATIS; CNRS UMR 5220; INSERM U1044; INSA-Lyon; UCBL, Université de Lyon, Villeurbanne, Rhône-Alpes, France, 2CHU Edouard Herriot; Department of digestive imaging, Hospices Civils de Lyon, Lyon, Rhône-Alpes, France, 3CHU Edouard Herriot; Department of Hepatology, Hospices Civils de Lyon, Lyon, Rhône-Alpes, France

Distinction between pure steatosis and NASH in patients with NAFLD is clinically important and drives the therapeutic strategy. While histology after liver biopsy is the gold standard for liver steatosis diagnosis and to establish the distinction between NASH and pure steatosis, inherent risk with a recognized morbidity and mortality, inter-observer variability and sampling errors renders this method unsuitable for longitudinal clinical monitoring, in particularly on children. Non-invasive quantification methods have been developed to quantify liver fat content. Nevertheless, these latter are not able to separate pure steatosis and NASH. Aim of this study was to evaluate the combination of liver intra-voxel incoherent motion imaging (IVIM) and a MRI fat quantification method at 3.0 T to make the distinction between NASH and pure steatosis. Preliminary results suggested that combining a fat quantification method with IVIM could be a relevant none invasive mean to evaluate steatosis severity and distinguish between pure steatosis and NASH.

15:06 0282.   
Comprehensive Assessment of Diffuse Liver Disease with Quantitative MRI Biomarkers of Steatosis, Fibrosis and Portal Flow: A Biopsy Correlation Study.
Alejandro Roldán-Alzate1, Alejandro Muñoz del Rio1, Rashmi Agni2, Adnan Said3, Oliver Wieben1,4, and Scott B. Reeder1,4
1Radiology, University of Wisconsin, Madison, WI, United States, 2Pathology, University of Wisconsin, Madison, WI, United States, 3Hepatology, University of Wisconsin, Madison, WI, United States, 4Medical Physics, University of Wisconsin, Madison, WI, United States

NAFLD is the most common type of chronic liver disease and a large and increasing number of NAFLD patients develop cirrhosis and liver. In this study we investigated the relationship between liver stiffness, fat content and portal venous flow using MRI compared to biopsy, in patients with diffuse liver disease. Results show positive correlation between normalized portal flow and liver stiffness, and a negative correlation between fat content and stiffness (independent of fibrosis). The combination of quantitative MRI biomarkers for fat content, stiffness and portal blood flow may provide comprehensive assessment for the diagnosis and treatment monitoring of diffuse liver disease.

15:18 0283.   
Initial in vivo Validation of a Hybrid Magnitude/Complex MRI-Based Method for Liver Fat Quantification
Ghaneh Fananapazir1, Xiaodong Zhong2, Lauren M.B. Burke1, Brian M. Dale3, Berthold Kiefer4, Daniel T. Boll1, and Mustafa R. Bashir1
1Radiology, Duke University Medical Center, Durham, NC, United States, 2MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, 3MR R&D Collaborations, Siemens Healthcare, Morrisville, NC, United States, 4MR R&D Collaborations, Siemens Healthcare, Erlangen, Germany

Hepatic steatosis can precede liver inflammation, chronic fibrosis, and ultimately liver failure and malignancy. A novel method has been developed to measure proton density fat fraction from a multi-echo MRI acquisition. This is a hybrid magnitude/complex data method which takes advantage of the insensitivity to phase error of magnitude-data techniques and the full 0-100% dynamic range of complex-data techniques. This study looked to validate this technique against co-localized T2-corrected single voxel spectroscopy. Agreement between these two methods was very strong. Additionally, this technique allows for assessment of the variability of disease within the liver as well as total lipid burden.