Prospective Validation of Repeatability of Shear Wave Dispersion Imaging for Evaluation of Non-alcoholic Fatty Liver Disease

Abstract

This study was aimed at evaluating the intra-observer repeatability of shear wave dispersion imaging (SWDI) for evaluation of non-alcoholic fatty liver disease and assessing inter-observer repeatability in asymptomatic volunteers, using a commercial ultrasound system. This prospective study was approved by our institutional review board and informed consent was obtained from all patients. In group I composed of patients with suspected or alleged non-alcoholic fatty liver disease (n = 71), two sessions of SWDI were performed by one radiologist for evaluation of intra-observer repeatability. In group II composed of asymptomatic volunteers (n = 19), three independent sessions were performed by three radiologists. Intra-observer and inter-observer repeatability was assessed using intra-class correlation coefficients (ICCs). For intra-observer repeatability, the ICC was 0.955 (95% confidence interval: 0.926-0.973), and subgroup analysis revealed that body mass index, ultrasound steatosis grade and liver function test abnormalities did not affect ICCs. The ICC for inter-observer repeatability was 0.800 (95% confidence interval: 0.572-0.916). Thus, SWDI had excellent intra-and inter-observer repeatability.

Keywords: Dispersion; Fatty liver disease; Repeatability; Shear wave elastography; Steatosis.