Strain elastography for assessment of liver fibrosis and prognosis in patients with chronic liver diseases.

BACKGROUND: Estimation of liver stiffness is essential in the treatment of liver diseases. Various procedures alternative to liver biopsy have been developed, and transient elastography using shear wave is an established method for evaluating liver stiffness and has been shown to be a prognostic indicator. In contrast, strain elastography (SE) has been applied to evaluate liver stiffness, however the significance remains uncertain.

METHODS: We retrospectively analyzed 598 patients who underwent SE to evaluate the ability of estimating liver stiffness and the prognosis. Elasticity index (EI) was evaluated as an indicator of liver stiffness in this study.

RESULTS: EI was increased as histological fibrosis advanced. EI was significantly different between mild fibrosis (F0-2) and advanced fibrosis (F3, 4). In contrast, EI was similar among those with different activity scores. EI showed better diagnostic performance in estimating advanced fibrosis than other serological markers and good reproducibility. Furthermore, EI was shown to be an independent prognostic factor in patients with chronic liver diseases and also with hepatocellular carcinoma (HCC) with advanced stage.

CONCLUSIONS: SE could estimate advanced liver fibrosis without influence of liver inflammation unlike other serological liver fibrosis markers. SE might be a prognostic factor in chronic liver diseases and HCC.