HIFU辐照离体牛眼晶状体致凝固性坏死出现时间与空化关系的定性研究

Qualitative research of the relationship between occurrence time of coagulation necrosis and cavitation during HIFU exposures

目的:研究高强度聚焦超声(high intensity focused ultrasound,HIFU)辐照离体牛眼睛所致热凝固性坏死出现的时间与空化的关系。方法:使用自制支架固定牛眼晶状体,使用不同辐照参数(100w-6s、200w-3s、300w-2s、600w-1s)的HIFU辐照离体牛眼晶状体,辐照过程中使用高速摄影系统摄录晶状体中凝固性坏死的形成过程,并用被动空化检测(passive cavitation detection,PCD)系统对辐照中牛眼晶状体中发出的声散射信号(acoustic emissions)进行检测后在LabVIEW开发平台上编程对其量化分析。辐照结束后,观察HIFU致牛眼晶状体中的损伤形态。结果:HIFU辐照牛眼晶状体,都产生了凝固性坏死,且出现的时间不同。100、200、300和600W功率的HIFU辐照中凝固性坏死出现的平均时间分别为1.921、1.109、0.627和0.240 s。辐照结束后,肉眼观察可见牛眼晶状体中形成的凝固性坏死大小和形态类似。除100W外,其余功率的HIFU辐照过程中均观察到了空化的发生,且辐照功率越大,空化越剧烈。结论:HIFU辐照中空化的发生影响凝固性坏死的产生,且空化越剧烈,凝固性坏死形成时间越短。

Objective： To study the relationship between currence time of coagulation necrosis and cavitation during HIFU exposures qualitatively. Methods： The bovine lens were exposed to HIFU with various parameters （100w- 6s, 200w- 3s, 300w- 2s and 600w- Is） after fixed using a homemade bracket. The high- speed photography device was used to record the formation process of coagulation necrosis in the bovine lens. Acoustic emissions were al~ detected by a passive cavitation detection （PCD） system and then processed with a program which was written on LabVIEW previously. The lens after irradiations were observed and photographed. Results： Coagulation necrosis were observed in all bovine lens during HIFU exposures while the occurrence time differentiated. The mean appear time of coagulation necrosis in bovine lens was 1.921, 1.109, 0.627and 0.240 s respectively after HIFU with the acoustic powers of 100, 200, 300 mad 600 W. Under naked eye, the volumes and shapes of lesions were similar after all exposures with different powers and times. Cavitation behaviors were detected during 200, 300 and 600 W acoustic powers HIFU irradiations, and the greater power, the more severe cavitation. Conclusions： Coagulation necrosis in the bovine lens were affected by cavitation during HIFU exposures, and the more severe cavitation, the shorter the ~currence time of coagulation necrosis.