Enhancing effects of microbubble contrast agent of different dosage on high-intensity focused ultrasound ablation in goat liver in vivo / 中华超声影像学杂志

ABSTRACT

Objective To investigate the enhancing effect of microbubble contrast agent SonoVue of different dosage on high-intensity focused ultrasound (HIFU) ablation in goat livers in vivo. Methods Twenty goats were divided into 4 groups randomly. Animals in group 1,2 and 3 were bolus-injected of 0.01 ml/kg,0. 03 ml/kg and 0.05 ml/kg of SonoVue intravenously before HIFU exposure, respectively,and those in group 4 were not given injections as control. After injection 20s, the livers were ablated using HIFU performed in the manner of a single dot set by a computer system using a clinical device. The frequency of HIFU was 0.8 MHz,the intensity of HIFU was 19 100 W/cm2 ,the distance from skin to the target liver tissue was 30 mm,the exposure time was set at 15 s for all animals in the four groups. All animals were euthanized 7 days after HIFU, volumes of coagulated necrosis were measured. Pathological examinations were performed to analysis the exposure regions. Results Under the same parameters of exposure, coagulated volumes in group 1,2 and 3 were larger than those in group 4, the difference was significant (P < 0.05),and the coagulated volumes increased gradually with the dosage of SonoVue increasing from group 1 to group 3, the difference was significant (P<0.05). Pathological examinations confirmed that there were no residual unaffected tissues within the exposed volume. Two remarkable changes were observed in one goat in group 37 days after HIFUthe surrounding adjacent tissue outside the reactive zone necrotized and the skin were destroyed. Conclusions The enhancing effects of microbubble contrast agent in HIFU ablation is related with the dosage of the microbubble contrast agent SonoVue. The higher the SonoVue dosage,the larger the volume destroy in the target tissue.