Magnetic Resonance Elastography Predicts Advanced Fibrosis in Patients With Nonalcoholic Fatty Liver Disease: A Prospective Study

Retrospective studies have shown that two-dimensional magnetic resonance elastography (2D-MRE), a novel MR method for assessment of liver stiffness, correlates with advanced fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). Prospective data on diagnostic accuracy of 2D-MRE in the detection of advanced fibrosis in NAFLD are needed. The aim of this study is to prospectively assess the diagnostic accuracy of 2DMRE, a noninvasive imaging biomarker, in predicting advanced fibrosis (stage 3 or 4) in well-characterized patients with biopsy-proven NAFLD. This is a cross-sectional analysis of a prospective study including 117 consecutive patients (56% women) with biopsyproven NAFLD who underwent a standardized research visit: history, exam, liver biopsy assessment (using the nonalcoholic steatohepatitis Clinical Research Network histological scoring system), and 2D-MRE from 2011 to 2013. The radiologist and pathologist were blinded to clinical and pathology/imaging data, respectively. Receiver operating characteristics (ROCs) were examined to assess the diagnostic test performance of 2D-MRE in predicting advanced fibrosis. The mean (+/- standard deviation) of age and body mass index was 50.1 (+/- 13.4) years and 32.4 (+/- 5.0) kg/m(2), respectively. The median time interval between biopsy and 2D-MRE was 45 days (interquartile range: 50 days). The number of patients with fibrosis stages 0, 1, 2, 3, and 4 was 43, 39, 13, 12, and 10, respectively. The area under the ROC curve for 2D-MRE discriminating advanced fibrosis (stage 3-4) from stage 0-2 fibrosis was 0.924 (P < 0.0001). A threshold of > 3.63 kPa had a sensitivity of 0.86 (95% confidence interval [CI]: 0.65-0.97), specificity of 0.91 (95% CI: 0.83-0.96), positive predictive value of 0.68 (95% CI: 0.48-0.84), and negative predictive value of 0.97 (95% CI: 0.91-0.99). Conclusions: MRE is accurate in predicting advanced fibrosis and may be utilized for noninvasive diagnosis of advanced fibrosis in patients with NAFLD.