连续高强度聚焦超声与脉冲高强度聚焦超声的生物学效应对比  

Comparison on biological effects of continuous and pulse high intensity focused ultrasound

作　　者：杨含[1] 白晋[1] 刁庆春[2] 龚晓波[3] 李发琪[1] 

机构地区：[1]重庆医科大学生物医学工程学院省部共建超声医学工程国家重点实验室超声医学工程重庆市市级重点实验室,重庆400016 [2]重庆市第一人民医院皮肤科,重庆400011 [3]超声医疗国家工程研究中心,重庆401121

出　　处：《中国介入影像与治疗学》2013年第2期69-72,共4页Chinese Journal of Interventional Imaging and Therapy

基　　金：国家重点基础研究发展计划(973计划)项目(2011CB707900);国家自然科学基金面上项目(30970827)

摘　　要：目的探讨相同辐照剂量的连续高强度聚焦超声(CHIFU)与脉冲高强度聚焦超声(PHIFU)辐照离体牛肝组织的生物学效应差异,以及占空比对PHIFU生物学效应影响。方法选取12块新鲜离体牛肝组织,采用定点点打方式辐照,设置辐照功率为300W,辐照深度为20mm,脉冲组(PHIFU组)按占空比分为1～5组,占空比及相应辐照时间分别为5%、120s,10%、60s,20%、30s,50%、12s和75%、8s;对照组(CHIFU组)辐照时间设为6s。辐照过程中通过MRI监测各辐照焦点温度,辐照后切开牛肝组织、观察靶区形态,测算坏死体积。结果辐照过程中对照组、脉冲3～5组最高温度分别为(95.60±11.50)℃、(89.60±12.60)℃、(89.90±12.10)℃和(94.10±9.70)℃,各组间差异均无统计学意义(P均>0.05),靶区组织为灰白色凝固性坏死;脉冲1、2组最高温度分别为(53.30±3.90)℃和(56.70±4.10)℃(P>0.05),靶区组织呈空洞状损伤。结论 CHIFU与高占空比PHIFU易形成热效应、造成靶区组织凝固性坏死,低占空比PHIFU主要通过非热效应造成靶区组织空洞状损伤,PHIFU辐照中占空比的大小对组织坏死体积无明显影响。Objective To explore the biological effects of continuous and pulse high intensity focused ultrasound（CHIFU） to ex vivo bovine livers tissues,and the impact of various duty cycle to PHIFU.Methods Twelve pieces in vitro bovine liver tissues were dot-exposed with HIFU（acoustic power 300 W,ablation depth 20 mm）.Subgroups 1 to 5 with different duty cycles（5%,10%,20%,50%,75%） were applied with PHIFU for 120 s,60 s,30 s,12 s,8 s,and the control group（CHIFU group） ablation time was set to 6 s.The ablation focus temperature was monitored by MRI.The liver tissue was cut up,the shape of target area was observed and necrosis volume was calculated.Results The maximal temperatures among control group,3—5 subgroup was（95.60±11.50）℃,（89.60±12.60）℃,（89.90±12.10）℃ and（94.10±9.70）℃,respectively,and there were not statistical differences（all P＆gt;0.05）.The target area showed coagulation necrosis.The maximal temperatures of subgroup 1 and group 2 was（53.30±3.90）℃ and（56.70±4.10）℃,respectively（P＆gt;0.05）.The target area had hole-shaped damage.Conclusion CHIFU and long duty cycle PHIFU are easy to form coagulation necrosis by thermal effect,and short duty cycle PHIFU is easy to form the hole shaped damage by non-thermal effect.In the PHIFU exposure,the length of duty cycle is not significant influence on necrosis volume of tissue.

关 键 词：高强度聚焦超声消融术 靶区温度 坏死体积 

分 类 号：R730.5[医药卫生—肿瘤]