Association Between Magnetic Resonance Imaging–Proton Density Fat Fraction and Liver Histology Features in?Patients?With Nonalcoholic Fatty Liver Disease or?Nonalcoholic Steatohepatitis

摘要

Background & AimsPatients with nonalcoholic fatty liver disease (NAFLD) or nonalcoholic steatohepatitis (NASH) often require histologic assessment via liver biopsy. Magnetic resonance imaging (MRI)-based methods for measuring liver triglycerides based on proton density fat fraction (PDFF) are increasingly used as a noninvasive tool to identify patients with hepatic steatosis and to assess for change in liver fat over time. We aimed to determine whether MRI-PDFF accurately reflects a variety of liver histology features in patients with NAFLD or NASH. MethodsWe performed a retrospective analysis of pooled data from 3 phase 2a trials of pharmacotherapies for NAFLD or NASH. We collected baseline clinical, laboratory, and histopathology data on all subjects who had undergone MRI analysis in 1 of the trials. We assessed the relationship between liver PDFF values and liver histologic findings using correlation and area under the receiver operating characteristic (AUROC) analyses. As an ancillary analysis, we also simulated a clinical trial selection process and calculated subject exclusion rates and differences in population characteristics caused by PDFF inclusion thresholds of 6% to 15%. ResultsIn 370 subjects, the mean baseline PDFF was 17.4% ± 8.6%. Baseline PDFF values correlated with several histopathology parameters, including steatosis grade (r?= 0.78;P 4 or advanced fibrosis. Although MRI-PDFF is an important imaging biomarker for continued evaluation of this patient population, liver biopsy analysis is still necessary.