This study investigated the usefulness of shear wave (SW) speed (related to viscoelasticity), dispersion slope (related to viscosity), and attenuation value (related to steatosis) measurements obtained using a new ultrasound (US) elastography system in patients with nonalcoholic fatty liver disease (NAFLD). In multivariable analysis with histologic features as independent variables, the fibrosis stage was significantly related to SW speed (P=0.04) and the lobular inflammation grade was significantly related to dispersion slope (P=0.02). However, the steatosis grade was not significantly related to attenuation value (P=0.07). SW speed is more useful than dispersion slope for predicting the degree of fibrosis, and dispersion slope is more useful than SW speed for predicting the degree of necroinflammation. Dispersion slope, which reflects viscosity, may provide additional pathophysiological insight into NAFLD.
