Viscoelasticity Measurement in Rat Livers Using Shear-Wave US Elastography

Abstract To investigate the usefulness of shear-wave speed and dispersion slope measurements obtained, using an ultrasound elastography system in rat livers with various degrees of necroinflammation and fibrosis. A total of 25 male Sprague Dawley rats were randomly divided into 5 groups of 5 rats each: G0 (control), G1 (CCl 4 injected twice a week for 1 wk), G2 (CCl 4 injected four times a wk for 1 wk), G3 (CCl 4 injected twice a wk for 6 wk) and G4 (CCl 4 injected twice a wk for 10 wk). The shear-wave speed (m/s) and the dispersion slope ([m/s]/kHz) were measured. Histologic features (inflammation, necrosis and fibrosis) were used as reference standards. In multivariable analysis with histologic features as independent variables, the fibrosis grade was significantly related to shear-wave speed ( p p