中文摘要：

目的观察微泡增强的超声空化效应在阻断兔肝血流实验中可能造成的不良反应。方法将21只健康新西兰大白兔随机均分为单纯超声组、一次超声空化组和两次超声空化组。超声空化处理采用经静脉注射脂质微泡（剂量0．1ml／kg体质量）联合峰值负压4．3MPa的脉冲式超声直接照射开腹暴露的肝脏5min。对一次超声空化组仅治疗1次；两次超声空化组治疗1次后间隔1h后重复治疗；单纯超声组用3ml生理盐水替代微泡。在治疗前及治疗后即刻、30、60min及48h对各组肝脏实施CEUS，计算各时间点峰值强度（PI）变化。实验结束后每组取一只动物，获取肝脏标本，行病理检查。结果一次超声空化治疗后即刻、30min，靶区肝实质由此前的均匀增强变为无增强，其PI值由（-51．88±士4．26）dB降至（-62．53±4．83）dB；48h后血流灌注恢复，PI值升至（-52．02±4．59）dB。两次超声空化治疗后治疗后即刻、30min，非增强缺损面积大于一次超声组，PI值变化与一次治疗组类似。单纯超声组治疗前、后CEUs无明显变化。病理发现一次超声空化组及两次超声空化组肝脏出现散在微小坏死灶。结论微泡超声空化阻断肝血流后，血流灌注可在48h后自行恢复，肝脏坏死范围较小。

英文摘要：

Objective To observe the adverse reactions of acoustic cavitation during CEUS on arresting hepatic blood per- fusion in rabbits. Methods Twenty-one healthy New Zealand rabbits were equally randomized to the ultrasound only group, one time of microbobbles acoustic cavitation group （one session group） and two times of microbobbles acoustic cavi- tation group （two sessions group）. The livers were surgically exposed and insonated by pulsed therapeutic ultrasound for 5 rain with a peak negative pressure of 4.3 MPa. The lipid microbubbles were intravenously injected at 0.1 ml/kg. Rabbits in one session group were treated by CEUS once, while in the two sessions group were treated twice within 1 h interval. In the ultrasound only group, microbubbles were replaced by 3 ml saline. CEUS was performed before and immediately, 30 min, 60 min and 48 h after treatment with analysis of peak intensity （PI）. Liver specimens were harvested 48 h after treatment. Results In the one session group immediately, 30 min after treatment, the treated region showed significant non-enhanced perfusion defect, and PI dropped from （--51.88±4.26）dB to （-62.53±4.83）dB. However, blood perfu- sion recovered and the PI rose to（-52.02±4.59）dB after 48 h. In the two sessions group, the perfusion defect seemed larger than that of one session group, and PI displayed a similar variation. The liver blood perfusion of the ultrasound only group showed no difference before and after treatment. Pathological examination found that sporadic small sized necrotic nodules scattered in the livers in one session group and two sessions group. Conclusion Hepatic blood perfusion can be dis- rupted by acoustic cavitation of microbubbles during CEUS in rabbits, but recover within 48 h with minor liver necrosis.