PHIFU辐照晶状体致凝固性坏死与空化关系的实验研究

Relationship between coagulation necrosis and cavitation induced by PHIFU

目的:研究相同剂量,不同辐照参数的脉冲高强度聚焦超声(pulsed high intensity focused ultrasound,PHIFU)辐照牛眼晶状体所致凝固性坏死的变化过程及其与空化效应的关系,探讨何种方式辐照效果最佳。方法:用不同声功率和占空比的PHIFU(A组对照组:60 W-100%,B组:120 W-50%,C组:240 W-25%,D组:500 W-12%)辐照牛眼晶状体,辐照过程中使用高速摄像系统实时拍摄凝固性坏死的变化,被动空化检测(passive cavitation detection,PCD)系统记录焦域处发出的声散射信息,分析辐照过程中两者之间的关系,并比较各参数辐照效果。结果:各组均发生凝固性坏死,C、D 2组相应RMS幅值在辐照开始时就增高,其凝固性坏死出现平均时间分别为(2.63±0.71)s、(2.45±0.68)s。其中D组凝固性坏死出现所需时间最短,坏死体积最大,能效因子(energy efficiency factor,EEF)值最小,空化发生剧烈。结论:总剂量相同的PHIFU辐照下,声功率500 W,占空比12%的辐照效果最好。空化效应的发生要早于凝固性坏死的出现。

Objective ：To study the relationship between coagulation necrosis and cavitation in bovine lens induced by PHIFU with different parameters,and to explore the best way of irradiation. Methods：Different sound power and duty cycle of PHIFU（group A, control groups：60 W-100%,group B：120 W-50%,group C：240 W-25%,group D：500 W-12%） was used to irradiate bovine lens;the real-time formation of coagulation necrosis was recorded using high-speed imaging device;the acoustic scattering at the fo- cal region was recorded by PCD system, and then the relationship between the irradiation process and cavitation was analyzed, and the effects of irradiation parameters was compared. Results：Coagulation necrosis was occurred in each group. At the beginning of irradia- tion,the root-mean-square（RMS）was increased in groups C and D, and the corresponding average time of appearing coagulation necrosis was （2.63 ± 0.71） s and （2.45 ± 0.68） s,respeetively. In group D,the occurrence time of coagulation necrosis was the shortest, the volume was the maximum,the energy efficiency faetor（EEF） was the minimum, and the cavitation occurred acutely. Conclusion： Under the same total dose of radiation PHIFU, sound power=500 W,duty cycle=12% is the best. Cavitation occurs earlier than the appearance of coagulation necrosis.