Zhao Xin, Zou Jianzhong, Wu Feng, Liu Fang, Jiao Jiao
College of Biomedical Engineering of, Chongqing Medical University, Chongqing, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2013 Jan;33(1):40-3.
To investigate the accuracy of ultrasound monitoring during pulsed high intensity focused ultrasound (PHIFU) treatment and improve the sensitivity of ultrasound monitoring of tissue necrosis caused by PHIFU treatment.
Bovine liver ex vivo was dot-exposed with HIFU at the therapeutic doses of 2000 J (group A) and 1440 J (group B). The two groups were further divided into groups A1 (power 100 W, duty cycle 100%, irradiate 20 s) A2 (power 100 W, duty cycle 50%, irradiate 40 s), A3 (power 100 W, duty cycle 40%, irradiate 50 s), B1 (power 120 W, duty cycle 100%, irradiate 12 s), B2 (power 100 W, duty cycle 50%, irradiate 24 s), and B3 (power 100 W, duty cycle 40%, irradiate 30 s). The gray scale changes in the ultrasonic images after the exposures were observed, and the correlation function of the image was calculated before and after the exposure. The accuracy of evaluations based on the correlation function and gray-scale changes was compared.
The correct rate of gray scale-based evaluation of tissue necrosis caused by PHIFU was only 51%, while that by correlation function-based evaluation reached 85%.
Monitoring of tissue necrosis caused by PHIFU treatment can not rely solely on evaluation of gray-scale change of the ultrasound images, and the correlation function-based evaluation can be more accurate and sensitive for that purpose.
探讨脉冲高强度聚焦超声（PHIFU）治疗过程中超声监测的准确性，提高对PHIFU治疗所致组织坏死的超声监测敏感性。
对离体牛肝进行点式高强度聚焦超声照射，治疗剂量分别为2000 J（A组）和1440 J（B组）。两组再进一步分为A1（功率100 W，占空比100%，照射20 s）、A2（功率100 W，占空比50%，照射40 s）、A3（功率100 W，占空比40%，照射50 s）、B1（功率120 W，占空比100%，照射12 s）、B2（功率100 W，占空比50%，照射24 s）和B3（功率100 W，占空比40%，照射30 s）。观察照射后超声图像的灰度变化，并计算照射前后图像的相关函数。比较基于相关函数和灰度变化的评估准确性。
基于灰度评估PHIFU所致组织坏死的正确率仅为51%，而基于相关函数评估的正确率达85%。
PHIFU治疗所致组织坏死的监测不能仅依赖于超声图像灰度变化的评估，基于相关函数的评估在此方面更准确、敏感。
