脉冲与连续高强度聚焦超声对离体牛肝表面消融的效果比较  

Efficacy of surface ablation with continuous versus pulsed high-intensity focused ultrasound in isolated bovine liver

作　　者：文静[1] 邹建中[1] 王琦[1] 马大钊 丁晓亚 

机构地区：[1]重庆医科大学生物医学工程学院、省部共建国家重点实验室、重庆市超声医学工程重点实验室、重庆市生物医学工程学重点实验室、重庆市微无创医学协同创新中心,重庆400016

出　　处：《第三军医大学学报》2017年第8期749-754,共6页Journal of Third Military Medical University

基　　金：国家重点基础研究发展计划(973计划,2011CB707900);国家自然科学基金委重大科学仪器设备研制专项资助项目(81127901);国家自然科学基金面上项目(11574039,11274404)~~

摘　　要：目的比较脉冲高强度聚焦超声(pulsed high-intensity focused ultrasound,PHIFU)与连续高强度聚焦超声(continuous high-intensity focused ultrasound,CHIFU)表面消融模式的消融效果,探讨优化HIFU表面消融模式的辐照策略。方法将40块牛肝组织按辐照方式不同分为A组(30块,PHIFU表面消融模式)和B组(10块,CHIFU表面消融模式),A组再按占空比均分为A1(10%)、A2(30%)、A3(50%)3个亚组,每个亚组10块。B超监控下,A、B组分别采用PHIFU与CHIFU表面消融模式对靶区进行辐照,辐照同时记录靶区内部温度,辐照后观察靶区边缘及其内、外未辐照区损伤情况,测算能效因子并分析温度时间曲线。结果能效因子:A1组<A2组<A3组<B组。靶区外部:仅B组出现明显热损伤;靶区边缘:各组均可形成封闭隔离带,A1组呈液性坏死,其余组呈凝固性坏死;靶区内部:组织损伤程度随占空比增大而增大。内部温度:除A1组,其余组最高温度均超过60℃。结论 PHIFU较CHIFU在提高消融效率、减少靶区外组织损伤上更有优势。PHIFU表面消融时,调整占空比可改变靶组织内部未辐照区的温升及损伤情况。Objective To compare the effect of surface ablation with continuous high-intensity focused ultrasound （CHIFU） and pulsed high=intensity focused ultrasound （PHIFU） and investigate the optimization of surface ablation mode with HIFU. Methods Forty samples of fresh bovine liver tissues were divided into group A （n=30） and group B （n=10） for surface ablation with PHIFU and CHIFU, respectively. According to the duty cycles, the samples in group A were divided into 3 equal subgroups with duty cycles of 10% （group A1）, 30% （group A2）, and 50% （group A3）. With ultrasonographic guidance, the target areas in the liver tissues were irradiated with PHIFU and CHIFU for surface ablation, and the temperature changes in the geometric center of the target area were recorded. After ablation, tissue damages in the peripheral area and the areas within and outside the target area were observed, the energy efficiency factor （EEF） was calculated, and the temperature-time curve was analyzed. Results Compared with that in group B, the EEF in the 3 subgroups in group A all reduced significantly （P〈0.05）, and the reduction became more prominent as the duty cycles increased. Thermal damage outside the target area was observed only in group B. In each group, confined lesions were formed following the ablation, and the irradiated areas showed liquid necrosis in subgroup A1 and coagulation necrosis in the other groups. Within the target area of ablation, the tissue damage was intensified as the duty cycle increased, and the peak temperature in the center of the target area exceeded 60 ℃ in all the groups only with the exception of group A1. Conclusion Compared with CHIFU surface ablation, PHIFU surface ablation has a greater ablation efficiency and reduces tissue damage outside the target area. In PHIFU peripheral ablation, the temperature and tissue damage of the non-irradiated internal tissue within the target area can be controlled by adjusting the duty cycles.

关 键 词：脉冲高强度聚焦超声 连续高强度聚焦超声 表面消融模式 

分 类 号：R312[医药卫生—基础医学] R454.2