Justin Hong-jie Tan MD, MS, Abstract Co-Author: Nothing to Disclose

Irene Mwangi MD, Abstract Co-Author: Nothing to Disclose

Tanya Wolfson MS, Abstract Co-Author: Nothing to Disclose

Masoud Shiehmorteza MD, Abstract Co-Author: Nothing to Disclose

Mark Bydder PhD, Abstract Co-Author: Research grant, General Electric Company

Claude B. Sirlin MD, Presenter: Research grant, Bayer AG, West Haven, CT Research grant, General Electric Company, Fairfield, CT Research grant, Bracco Group Contract, Isis Pharmaceuticals, Inc Contract, Wyeth Speaker Bureau, Bayer AG Consultant, Bayer AG

Jeffrey B. Schwimmer MD, Abstract Co-Author: Nothing to Disclose

Joel Levine MD, Abstract Co-Author: Nothing to Disclose

Tarek I. Hassanein MD, Abstract Co-Author: Nothing to Disclose

00030490-DMT et al, Abstract Co-Author: Nothing to Disclose

To determine if liver fat fraction as estimated by a novel multiecho gradient-recalled-echo sequence at 1.5T or 3T MR scanner could be used to identify patients with low risk of non-alcoholic steatohepatitis.

Retrospective, cross-sectional IRB approved and HIPAA compliant study.73 subjects (13 female, 60 male; mean age 17.1 ± 10.4 years, range 8-61) were selected from a database of an ongoing study on non-alcoholic fatty liver disease. All subjects had liver biopsy within 4 months (mean 28 ± 29 days) of MR liver fat fraction (FF) quantification.For MR liver FF quantification, multisection gradient recalled echo axial images of the liver were acquired using a low flip angle (10°) to minimize T1 effects and 6 echoes at serial opposed-phase and in-phase echo times.FF was calculated by modeling signal intensity as a function of echo time. The model accounted for fat-fat and fat-water spectral interference while correcting for T2*. For each biopsy sample, a pathologist categorized the likelihood of non-alcoholic steatohepatitis (NASH) as unlikely, possible, or definite. Biopsy variables of NASH (lobular inflammation, fibrosis, hepatocyte balloon degeneration, fibrosis), and pathologist-determined likelihood of NASH were binarized into presence or absence of disease for statistical analysis.

MR FF was significantly lower in livers without NASH than in livers with NASH (p<0.05), and in livers with lobular inflammation than in those without (p <0.05). There was no significant difference in FF between livers with and without portal inflammation, between livers with and without hepatocyte ballooning, and between livers with and without fibrosis. No liver with FF ≤10% was classified as NASH by the pathologist. 23 of 73 livers (44%) with FF >10% had histological features of NASH.

A liver fat fraction ≤ 10% as quantified by MR excludes the presence of NASH in this cohort. A FF > 10% is not a reliable marker of disease severity. Because patients with advanced NAFLD cirrhosis may have low liver fat content, further study is necessary to determine how our findings may be applied to the general population in a way that does not falsely label cirrhotics as having isolated steatosis.

Liver fat fraction as determined by multiecho gradient-recalled-echo MR sequence could be used to identify patients with low risk of NASH and thus exempt them from unnecessary biopsies.

Tan, J, Mwangi, I, Wolfson, T, Shiehmorteza, M, Bydder, M, Sirlin, C, Schwimmer, J, Levine, J, Hassanein, T, et al, 0, Correlation of Histological Markers of Non Alcoholic Steatohepatitis with Liver Fat Fraction Quantified Using Magnetic Resonance Imaging.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8013922.html