摘要
目的探讨B超监控脉冲高强度聚焦超声(PHIFU)辐照的可行性。方法将高强度聚集超声(HIFU)治疗系统设置为脉冲工作状态,调整脉冲重复频率为4Hz,辐照剂量分别为180、240、300J,每个剂量又分为4个占空比时间组(1%～4%)。PHIFU定点辐照离体牛肝组织,辐照结束后比较靶区辐照前后的声像图变化和灰度值变化,切开牛肝组织肉眼观察靶区的形态变化,重复实验10次。取靶区与正常组织交界处组织行HE染色。结果 PHIFU辐照离体牛肝组织后,靶区B超图像出现低回声区,靶区灰度差值为负值,且各剂量下所有占空比时间组灰度差的负值比较差异无统计学意义(P均>0.05)。各剂量下,占空比为1%～3%的PHIFU辐照后切开靶区组织有清亮液体流出,靶区仅见空洞,其内未见凝固性坏死;占空比为4%的PHIFU辐照后可见泥浆样液体流出。结论通过观察PHIFU辐照后的灰度值和声像图变化,可以间接指导制定治疗剂量和判断治疗效果。
Objective To explore the feasibility of monitoring pulsed high intensity focused ultrasound （PHIFU） expo- sure with B-mode-ultrasound. Methods HIFU system was set to pulse mode, with 4 Hz pulse recurrence frequency. HI- FU with dosage of 180, 240, and 300 J was used separately to irradiate the fresh ex vivo ox liver, and each dosage was di- vided into 4 irradiance duty cycle-time groups （1%-4%）, Changes of ultrasonography and grey value Of the target area were compared before and after ultrasonic irradiation. The livers were cut, and the largest damage areas were observed. This process was repeated for 10 times. Pathologic examination was performed on all the samples at the interface of target volume and normal tissue. Results After PHIFU irradiation, hypoecho regions were found in the target areas, and the difference of gray value was not significant. There was no statistical difference of the same doses of duty cycle-time groups （all P〉0.05）. The visible damages in liver tissue exposed to PHIFU with 1%, 2%, and 3% duty cycle-time groups ap- peared as clear liquid flows, while mud sample liquid flows were noticed in duty cycle of 4% group. Conclusion The chan- ges of gray scale and ultrasonography in the target areas during PHIFU therapy can be used to guide HIFU dosage and judge curative effect of PHIFU.
出处
《中国介入影像与治疗学》
CSCD
2012年第10期752-756,共5页
Chinese Journal of Interventional Imaging and Therapy
基金
国家重点基础研究发展计划(973计划)项目(2011CB707902)
国家自然科学基金面上项目(30970827)
关键词
脉冲高强度聚焦超声
非热损伤
靶区
低回声区
灰度
Pulsed high intensity focused ultrasound
Non-thermal erosion
Target area
H ypoecho
Gray value
