Evaluation of liver fibrosis by investigation of hepatic parenchymal perfusion using contrast-enhanced ultrasound: an animal study.

Purpose: To investigate the value of assessing the hepatic parenchymal perfusion in contrast-enhanced ultrasound (CEUS) for evaluating liver fibrosis, using an animal model.

Methods: Seventy Sprague-Dawley rats were divided into experimental (n = 35) and control (n = 35) groups. In the experimental group, liver fibrosis was induced by intraperitoneal injection of carbon tetrachloride. CEUS of the liver was performed at a 2-week interval for 14 weeks. Signal intensity of liver parenchyma was analyzed with time-intensity curves. Histologic examination of liver specimens of the animals was performed to assess the fibrosis stage.

Results: The peak signal intensity of hepatic parenchymal perfusion in stage 2-3 fibrosis was significantly lower than that in stage 0-1. The time to peak intensity of hepatic parenchymal perfusion was significantly longer in the experimental group than the control group, and in the stage 3 fibrosis than in stages 0-2 fibrosis. Using time to peak intensity of hepatic parenchymal perfusion to distinguish stage 3 fibrosis and stages 0-2 fibrosis, the optimum cutoff was 75,000 milliseconds with the sensitivity and specificity of 67% and 78%, respectively.

Conclusions: This animal study showed that CEUS has the potential to be a complementary imaging tool in the evaluation of liver fibrosis.