Contrast-enhanced ultrasound and acoustic radiation force impulse elastography in evaluating efficacy of microwave ablation on hepatic alveolar echinococcosis in rats / 中国介入影像与治疗学

ABSTRACT

Objective: To observe the value of contrast-enhanced ultrasound (CEUS) and acoustic radiation force impulse (ARFI) elastography in evaluating efficacy of microwave ablation (MWA) on hepatic alveolar echinococcosis in rats. Methods: Totally 40 HAE rat models were divided into experimental group (n=30) and control group (n=10). Rats in experimental group underwent ultrasound-guided MWA, while those in control group received routine feeding. Routine 2D ultrasound, CEUS and ARFI were used to measure the maximum diameter of lesions before and 1 month later. The changes of mean gray scale ratio and shear wave velocity (SWV) in marginal zone of lesions in experimental group were compared with pathologic findings. Then the rats were all scarified, and routine HE staining, CD34 immunohistochemical staining and Masson staining were performed to count the microvessel density (MVD) and fibrosis area at the edge of lesions. Results: There were 19 rats (21 lesions) in experimental group and 10 rats (10 lesions) in control group. One month after MWA, the maximum diameter of lesions obtained with 2D ultrasound, CEUS and ARFI became smaller in experimental group (all P0.05). One month after MWA, the mean gray scale ratio of ablation edge in experimental group was lower, while SWV value was higher than that before (both P<0.001). MVD of the ablation edge in experimental group was lower than that in control group (P<0.001), and the fibrosis area of experimental group was higher than that of control group (P<0.001). MVD was positively correlated with the gray scale ratio at the ablation edge (r=0.541, P=0.011), and SWV was positively correlated with the fibrosis area of Masson (r=0.494, P=0.023). Conclusion: Both CEUS and ARFI had certain application value for evaluation on efficacy of microwave ablation for treatment of HAE in rat models.