占空比对脉冲高强度聚焦超声辐照离体牛肝所致损伤的影响  

Effect of Duty Cycle on Ex Vivo Bovine Liver Treated with Pulsed High Intensity Focused Ultrasound

作　　者：刘芳[1] 邹建中[1] 艾慧坚[1] 焦娇[1] 赵欣[1] 

机构地区：[1]重庆医科大学生物医学工程学院,重庆市400016

出　　处：《中国超声医学杂志》2013年第1期75-78,共4页Chinese Journal of Ultrasound in Medicine

基　　金：国家重点基础研究发展计划(No.973计划);(No.2011CB707902);国家自然科学基金重点项目(No.30830040);国家自然科学基金面上项目(No.30970827)

摘　　要：目的探讨脉冲高强度聚焦超声(pulsed high intensity focused ultrasound,pHIFU)的占空比对其辐照离体牛肝所致损伤的影响。方法将pHIFU的声功率设为300 W(声强为26 500 W/cm^2),脉冲重复频率为100 Hz,辐照深度为20 mm。以3%、6%、9%、12%和15%的占空比分别辐照离体牛肝组织10 s。辐照中测量靶区温度,辐照结束后,切开牛肝组织,观察各个参数的pHIFU辐照后产生损伤的性状,取损伤组织HE染色后,行光镜观察。结果占空比为3%、6%时平均最高温度为(35.78±3.35)℃和(36.76±3.88)℃,且肉眼观察到焦点处损伤呈空洞状,内见清亮液体;9%时平均最高温度为(50.45±3.23)℃且在焦点处可见空洞中有匀浆物质;12%、15%时平均最高温度为(60.00±5.65)℃和(63.14±4.11)℃,且肉眼看见明显的凝固性坏死。HE染色后,空洞损伤区镜下可见组织缺失,凝固性坏死区主要表现为胞浆淡染,细胞核固缩、染色质边集。随着占空比的增加,组织非热损伤大小形态改变不明显,热损伤大小则呈增大趋势(P<0.05)。结论通过调整pHIFU的占空比,能使组织损伤性状发生改变。Objective To investigate the effect of duty cycle on ex vitro bovine liver treated with pulsed high in- tensity focused ultrasound （pHIFU）. Methods The bovine liver tissues were exposed to pHIFU with the duty cycle of 3% ,6% ,9% ,12% ,15% for 10 s with the acoutstic power of 300 W, 100 Hz pulse recurrence frequency （PRF）, 20ram irradiation depth. Measure the temperature of the target in irradiation,after the irradiations, the gross morpho- logical changes of target areas were observed by visual inspection, and the specimens were hematoxylin-eosin stained. Results The average maximal temperature of group 3 % and 6% were （35.78±3.35）℃ and （36.76±3.88）℃, the visible damages in livers were holes. The average maximal temperature of group 9% was （50.45±3.23）℃ ,the visible damage in livers were holes with homogenate materials. The average maximal temperature of group 12% and 15% were （60.00±5.65）℃ and （63.14±4.11） ℃, the visible damages in livers were cogulative nerosis. After hematoxy- lin-eosin staining,the void damagearea was tissue defect, coagulative necrosis in the main performance for cytoplasm light dye,became pyknotic nuclei chromatin edge sets. Along with the increase of duty cycle, the changes of the non- thermal damage size and form of tissue were not obvious, the changes of thermal damage were in a trend of increase （P〈0.01）. Conelusions pHIFU can make tissue damage character change through adjusting duty cycle.

关 键 词：高强度聚焦超声 组织摧毁术 温度 

分 类 号：R454.3[医药卫生—治疗学]