Ultrasonographic grayscale findings related to fibrosis in patients with non-alcoholic fatty liver disease: comparison with transient elastography and Fib-4 index

Purpose: Fibrosis is a predictor of mortality in patients with non-alcoholic fatty liver disease (NAFLD). In our institution, abdominal ultrasonography has been performed based on a unified method consisting of 25 images. We investigated ultrasonographic grayscale findings related to fibrosis in patients with NAFLD. Methods: This retrospective study comprised 41 cases of pathologically proven fatty liver between January 2015 and September 2020. A total of 26 ultrasonographic findings were subjectively evaluated. These findings, transient elastography (TE) with M probe, and FIB-4 index were compared with fibrosis stage. Results: The frequency of roughness of the dorsal side of the surface (p < 0.001), heterogenicity of the parenchyma (p = 0.003), narrowing of the hepatic vein (p = 0.004), and splenomegaly (p < 0.001) were strongly correlated with the fibrosis stage. Logistic regression analysis for stage ≥ 3 showed narrowing of the hepatic vein (odds ratio [OR] 5.860, p = 0.031) and splenomegaly (OR 6.290, p = 0.028). Logistic regression analysis for stage 4 showed roughness of the ventral side of the surface (OR 42.0, p = 0.019). The AUROC for stage 3 and stage 4 with the number of positive ultrasonographic findings was 0.856, and 0.940, respectively. The AUROC for F3 and F4 with TE was 0.831 and 0.861, respectively. The AUROC for stage 3 and stage 4 with FIB-4 index was 0.815 and 0.806, respectively. Conclusions: Narrowing of the hepatic vein, roughness of the dorsal side of the surface, heterogenicity of the parenchyma, and splenomegaly and their combination could predict fibrosis in patients with NAFLD.