Assessment of Nonalcoholic Fatty Liver Disease in Rats Using Quantitative Dynamic Contrast-Enhanced MRI.

Abstract

To evaluate the usefulness of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the assessment of nonalcoholic fatty liver disease (NAFLD) severity. Liver DCE-MRI at 3.0T was performed in 36 adult Sprague-Dawley rats with methionine choline-deficient diet-induced NAFLD and 10 untreated control rats. Pharmacokinetic parameters of DCE-MRI including Ktrans , Kep , Ve , Vp , and hepatic portal index (HPoI) were measured using the dual-input extended Tofts model. Animals were categorized as normal (n = 10), simple steatosis (SS, n = 11), borderline nonalcoholic steatohepatitis (bNASH, n = 20), and NASH (n = 5) subgroups according to the NAFLD activity score system, and classified into F0 (n = 24), F1 (n = 11), F2 (n = 7), and F3 (n = 4) subgroups according to an established scoring system. DCE-MRI parameters were compared. Receiver operating characteristic analyses were performed to assess the diagnostic performance of various DCE-MRI parameters in grading NAFLD activity and staging liver fibrosis. Ktrans and HPoI were elevated with increasing severity of NAFLD activity and increased fibrosis stage. The areas under the receiver operating characteristic curve (AUROCs) of HPoI ranged from 0.895-0.951 for discriminating between different grades of NAFLD activity, and the AUROC was 0.852 for discriminating F0 stage from overall F1-F3 stages. The AUROC of Ktrans for discriminating non-NASH from bNASH and NASH groups was 0.968, and 0.898 for discriminating between normal and overall fibrosis groups. DCE-MRI may play a role in assessing NAFLD severity. 1 J. MAGN. RESON. IMAGING 2017;45:1485-1493.