Evaluation of liver fibrosis in a rat model by acoustic radiation force impulse elastography / 中华超声影像学杂志

ABSTRACT

Objective To investigate the usefulness of acoustic radiation force impulse (ARFI) elastography for noninvasive evaluation of liver fibrosis in rats.Methods A total of 70 male Wistar rats were included in the group for dimethylnitrosamine (DMN)-induced liver injury,and 10 saline-injected rats were used as normal control.Hepatic injury was induced by a single intraperitoneal injection of DMN at a dose of 50 mg/kg of body weight.Several rats in the group with DNM injected and the normal control group were randomly selected and sacrificed at each of the following post-injection time:day 5,7,10,14,21,24,and 28.And their livers were taken for pathology analysis.All the rats underwent ARFI elastography before sacrificed in order to acquire a shear wave velocity (Vs) to represent liver stiffness.Correlation between Vs and the histological finding was analysed.ResultsAmong 58 successfully modeled rats,9,13,14 and 12 rats were found to be with S1,S2,S3 and S4 of liver fibrosis pathologically,respectively.And 10 rats were found to be with severe inflammatory activity without any fibrosis.Values of Vs increased with the stage of liver fibrosis ( P ＜0.05).There was a significant correlation between Vs and stage of liver fibrosis ( r =0.947,P =0.000).The areas under ROC curve for the diagnosis of fibrosis S≥S1,S≥S2,S≥S3 and S=S4 were 0.983,0.995,0.999 and 0.964,respectively;for the cutoff values of Vs were 1.59 m/s,2.13 m/s,2.33 m/s and 2.51 m/s,respectively,the sensitivity was 95.8％,92.3％,100％ and 84.6％,and specificity was 100％,100％,96.9％ and 95.6％,respectively.The values of Vs in the group with severe inflammatory activity were significantly higher than those in the control group ( P =0.000).ConclusionsARFI has a relatively high value in the evaluation of liver fibrfosis in rats,while severe inflammatory activity may affect its accuracy.