Value of contrast-enhanced ultrasound using perflubutane microbubbles for diagnosing liver fibrosis and cirrhosis in rats.

We determined the ability of contrast-enhanced ultrasound (CEUS) using perflubutane microbubbles to diagnose liver fibrosis and cirrhosis in rats using histology as the reference standard. Fibrosis was induced by oral administration of carbon tetrachloride to 32 Wistar rats. Features with baseline ultrasound (US) and enhancement level of liver and spleen with CEUS were obtained. In the post-vascular phase of CEUS, images of normal livers (n = 5) were significantly brighter than images of fibrotic (n = 6) and cirrhotic livers (n = 13) by quantitative analysis (all p < 0.05). The contrast between livers and spleens in rats with cirrhosis was quantitatively greater than that in normal rats and rats with fibrosis (all p < 0.05). Compared with US, CEUS improved sensitivity from 63% to 84% and accuracy from 71% to 88%. Specificity was 100% for both. The increased value of CEUS in diagnosing liver fibrosis and cirrhosis in rats supports its evaluation in clinical trials.