骨骼对于高强度聚焦超声聚焦影响的实验研究  

Research on the influence of bone on high intensity focused ultrasound focusing

作　　者：曾苗苗[1] 钱宇晗 常诗卉[1] 菅喜岐[1] 

机构地区：[1]天津医科大学生物医学工程与技术学院,天津300070

出　　处：《天津医科大学学报》2016年第4期291-294,共4页Journal of Tianjin Medical University

基　　金：国家自然科学基金资助项目(81272495)

摘　　要：目的:测定高强度聚焦超声(HIFU)经过羊肩胛或人体离体颅骨形成的声压场及焦域,研究骨骼对HIFU聚焦的影响。方法:单阵元换能器发射超声波,经羊肩胛骨或者人体颅骨聚焦,通过水听器测量形成声场,通过含蛋清仿组织体模测量不同辐照条件形成的焦域大小。结果:羊肩胛骨及人体颅骨均可对声压造成极大的衰减;经骨骼后在激励功率达80 W时焦点声压与纯水中激励功率2 W相近,羊肩胛骨激励条件250 W、辐照时间3 min下可使仿体组织产生焦域;颅骨则在最大强度300 W、5 min下无焦域产生。结论:HIFU经骨骼聚焦时,增大输入功率或辐照时间,焦域体积增大。在单阵元换能器辐照环境下,经骨骼聚焦困难,焦点声压较低,形成焦域较小或无焦域形成,增大时间骨骼易产生热损伤。Objective： To measure the sound pressure field and focal regions of high intensity focused ultrasound （HIFU） to determine the effect of bone on ultrasound focusing. Methods： A single-element transducer was used for emitting ultrasound, The sound pressure was measured by hydrophone, and the focal regions were measured by egg-white tissue-mimicking phantom after sound wave spread through scapula of sheep or human skull. Results： Scapula of sheep and human skull both resulted in severe attenuation of sound pressure; similar sound pressure was observed in hydrophone when driving power was set to 2 W in degassed water and 80 W after scapula of sheep was added, and a focal region was generated in egg-white tissue-mimicking phantom with 250 W, 3 min; at maximum intensity 300 at 5 min, no focal region was observed when sound wave went through human skull. Conclusion： The focal regions increase with driving power or irradiation time. The sound pressure is low and focal regions are small or absent in the condition of the single-element. Increasing the irradiation time may cause thermal damage in bones.

关 键 词：高强度聚焦超声 羊肩胛骨 颅骨 仿组织体模 

分 类 号：R454.3[医药卫生—治疗学]