RESUMO
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 HIFU:the 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.
RESUMO
Objective To investigate the feasibility of enhancing therapeutic effects on goats' liver in vivo treated by high intensity focused ultrasound(HIFU)combined with microbubble contrast agent SonoVue.Methods Fifteen Nanjiang goats were adopted,own control was adopted in this study.One group received purely HIFU therapy(control group),another one was radiated with HIFU combined with SonoVue contrast agent(SonoVue group).The HIFU irradiating mode was dotted with 30 mm focal length and 150 W,250 W,350 W acoustic power respectively,and the exposure time was 15 s.Animals were sacrificed and dissected 24h later,and the sizes of necrotic region were measured.Specimens were collected for histological inspection.Results Under the same parameter of exposure,the maximum length,width,depth,and the mean volume of the tissue coagulated by HIFU in the SonoVue group were all significantly greater than those in control group(P＜0.05),the change of volume coagulated tissue was much more significant with the increase of the acoustic power.The energy effciency factor (EEF)of SonoVue group was significantly smaller than that of control group(P＜0.05).The demarcation line between the necrosis and normal region was clear and the necrosis was complete,no living cell.The boundary exist amount of bubbles.Conclusions The therapy of HIFU combined with microbubble eontrast agent can substantially enhance the biological effects of the treatment and improve the efficiency of HIFU therapy on goats liver.