聚焦超声辐照仿组织体模过程中实时气泡活动及其对损伤的影响  

Real-time bubble activities and its effects in process of irradiation by focused ultrasound in tissue-mimicking phantom

作　　者：李成海[1] 王静[1] 李非[1] 王琦[2] 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重点实验室,重庆400016 [2]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》2015年第7期437-440,共4页Chinese Journal of Interventional Imaging and Therapy

基　　金：国家自然科学基金(81127901;11274404);国家重点基础研究发展计划(973计划)项目(2011CB707900;2012CB722402)

摘　　要：目的探讨聚焦超声辐照仿组织体模过程中沸腾气泡和空化气泡的演变及其对损伤的影响。方法以聚焦超声辐照仿组织体模30 s。采用连接在体视显微镜上的高速摄影机实时监控辐照过程中的气泡活动和损伤演变,同时进行被动空化检测。在相同条件下分别重复8次实验。结果在沸腾气泡产生前,未见宽带噪声增加,损伤同时向声源方向和远离声源方向呈＂雪茄＂状线性增长;毫米级沸腾气泡瞬时产生后,迅速破裂成大量微米级气泡,而后宽带噪声出现阶跃性增强并持续至辐照结束,同时损伤范围快速增大并向声源方向发展,形状由＂雪茄＂状变为＂蝌蚪＂状;沸腾气泡完全破裂时间[（9.79±1.86）s]与3～7 MHz宽带噪声出现阶跃性增强的时间[（9.75±2.84）s]差异无统计学意义（P〉0.05）。结论毫米级沸腾气泡破裂成大量微米级气泡后为空化提供了空化核,也成为损伤向声源方向前移、范围快速非线性增大及损伤形状由＂雪茄＂状变为＂蝌蚪＂状的原因。Objective To investigate the variations of boiling bubble,cavitation bubbles and the effects during focused ultrasound irradiation in tissue-mimicking phantom. Methods Irradiation by focused ultrasound was performed on tissue-mimicking phantom for 30 s. The bubble activities and lesion variation were monitored in real time by high-speed camera connected with stereo microscope. Meanwhile,the passive cavitation detection was done. The experiment was repeated for 8 times under the the same condition. Results Before boiling bubble occurred,no broadband noise increased. The lesion displayed as the shape of ＂ cigar＂ and grew linearly both toward and away from the direction of sound source. After the bubble produced instantaneously,millimetersized boiling bubbles rapidly bursted into quantity of micron bubbles. Then step-enhancement of broadband noise appeared and stayed until the end of sonication. The range of lesion increased rapidly and grew toward the direction of sound source simultaneously. And the shape of lesion changed from ＂ cigar＂ to ＂ tadpole＂. The time of boiling bubble collapsed completely was（ 9. 79 ±1. 86） s and that of step-enhancement on 3—7 MHz broadband noise appeared was（ 9. 75 ± 2. 84） s. There was no statistical difference of time（ P〈0. 05）. Conclusion Millimeter-sized boiling bubbles bursting into quantity of micron bubbles provides nuclei for cavitation and becomes a reason of lesion grow forward in the direction of sound source,the range of lesion nonlinearly increases rapidly and the lesion shape change from ＂ cigar＂ to ＂ tadpole＂.

关 键 词：超声学 仿组织体模 气泡 损伤 

分 类 号：R445.1[医药卫生—影像医学与核医学]