Background: The definitive diagnosis of nonalcoholic steatohepatitis (NASH) is currently based on histopathological assessment. This study aimed to elucidate the utility of a novel noninvasive method, three-dimensional magnetic resonance imaging (3D-MRI), for diagnosing advanced fibrosis in patients with NASH, using histopathological diagnosis as the reference standard.
Methods: This retrospective study included 30 consecutive patients who had been diagnosed with NASH by histopathology and had undergone 3D-MRI before biopsy. 3D-MRI provided a three-dimensional reconstruction of the liver from contrast-enhanced hepatobiliary phase MR images. In the present study, histopathological advanced fibrosis was defined as stage 3 and 4 NASH. Advanced fibrosis, diagnosed by 3D-MRI, was considered to be diffuse irregularity of the entire surface of the liver. The diagnostic features of 3D-MRI and the noninvasive evaluation systems (APRI, FIB-4 index, and BARD score) for identifying advanced and nonadvanced fibrosis of NASH were determined and compared.
Results: Nine (30 %) of the 30 study patients were diagnosed histopathologically with advanced fibrosis, and 11 (37 %) of 30 patients were diagnosed with advanced fibrosis using 3D-MRI. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 3D-MRI for diagnosing advanced fibrosis were 100, 90, 82, and 100 %, respectively. The sensitivities of APRI, the FIB-4 index, and BARD score ranged from 78 to 89 %, the specificities from 71 to 90 %, the PPVs from 54 to 78 %, and the NPVs from 88 to 94 %.
Conclusion: Compared with the common noninvasive methods for diagnosing advanced fibrosis associated with NASH, 3D-MRI was more accurate.
Keywords: 3D-MRI; Advanced fibrosis; Nonalcoholic fatty liver disease; Nonalcoholic steatohepatitis; Virtual MR-laparoscopy.