MRI findings in nonalcoholic steatohepatitis: correlation with histopathology and clinical staging

PurposeTo evaluate magnetic resonance imaging (MRI) findings of nonalcoholic steatohepatitis (NASH) and to determine the correlation of MRI findings with histopathology and Mayo End-Stage Liver Disease (MELD) score.Materials and MethodsThirty patients (18 males, 12 females; mean age: 57±8.9 years; age range: 35–71 years) with histopathologically proven NASH who underwent MRI examinations between January 2001 and October 2005 were included in the study. Two radiologists retrospectively reviewed all magnetic resonance (MR) examinations in consensus to evaluate the presence and extent of predetermined findings of NASH including liver steatosis, early patchy liver enhancement indicating inflammation and liver fibrosis. The findings detected on MRI were correlated and compared to histopathological findings and MELD score by using nonparametric Spearman correlation coefficient and Kruskal–Wallis analysis of variance.ResultsLiver steatosis was observed in 10 of 30 patients; early patchy liver enhancement, in 8 of 30 patients and liver fibrosis in 19 of 30 patients on MR images. Liver fibrosis was reticular in all these patients. There were statistically significant moderate correlations between MRI findings of liver steatosis and histopathologic grades of steatosis (r=0.43; P<.05), and between MRI findings of fibrosis and histopathologic stages of fibrosis (r=0.61; P<.001). Early patchy enhancement did not demonstrate statistically significant correlation with inflammation (P=.28). There was no statistically significant overall correlation between MRI findings of NASH and MELD score.ConclusionMRI findings of liver steatosis and fibrosis in NASH showed moderate correlations with histopathologic grades of steatosis and stages of fibrosis, but MRI findings of NASH did not demonstrate any significant correlations with MELD score.