Detection of non-alcoholic steatohepatitis in patients with morbid obesity before bariatric surgery: preliminary evaluation with acoustic radiation force impulse imaging

Objective To investigate the utility of acoustic radiation force impulse (ARFI) imaging, with the determination of shear wave velocity (SWV), to differentiate non-alcoholic fatty liver disease (NAFLD) from non-alcoholic steatohepatitis (NASH) in patients with morbid obesity before bariatric surgery. Methods Thirty-two patients with morbid obesity were evaluated with ARFI and conventional ultrasound before bariatric surgery. The ARFI and ultrasound results were compared with liver biopsy findings, which is the reference standard. The patients were classed according to their histological findings into three groups: group A, simple steatosis; group B, inflammation; and group C, fibrosis. Results The median SWV was 1.57 ± 0.79 m/s. Hepatic alterations were observed in the histopathological findings for all the patients in the study (100 %), with the results of the laboratory tests proving normal. Differences in SWV were also observed between groups A, B and C: 1.34 ± 0.90 m/s, 1.55 ± 0.79 m/s and 1.86 ± 0.75 m/s ( P