靶向纳米微泡下高强度聚焦超声增效的声像图相关函数的应用研究

目的探讨在靶向纳米微泡条件下,用高强度聚焦超声(HIFU)辐照后,声像图相关函数与HIFU辐照发生凝固性坏死的关系,以提高监控超声的判断灵敏度。方法 60只双侧第二乳腺建模成功的VX2移植性肿瘤兔随机分为90 W,120 W,150 W组,每组20只,采用HIFU定点辐照,辐照时间统一为3 s,辐照左侧肿瘤时注射微泡造影剂,右侧作对照,观测靶区辐照前后声像图变化和灰度值变化,并对靶区声像图进行相关函数运算,比较灰度判别方式与相关函数判别方式的准确性与灵敏性。结果对120个样本进行辐照前后声像图相关函数分析,总判对率为83.3%,高于灰度判对率68.3%,其差异有明显统计学意义(P<0.05);同一辐照条件下,微泡组坏死样本声像图相关函数平均值低于对照组,其差异有统计学意义(P<0.05)。结论运用相关函数分析辐照前后靶区声像图,较灰度评价,其准确性、灵敏性更高,能有效提高HIFU疗效。

Study of the sonographic functions in targeted high-intensity focused ultrasound using nanoscale bubbles

Objective To improve the detection sensitivity of coagulative necrosis caused by high intensity focused ultrasound(HIFU) exposure.Methods Sixty rabbits bearing VX2 breast neoplasms at the second bilateral breast were divided randomly into 3 groups(n=20) for targeted HIFU exposure at 90,120,or 150 W for 3 s.With the right breast neoplasms as the control,the left ones were irradiated following nanoscale bubble injection.The ultrasonograms generated before and immediately after the exposure were analyzed for changes in the gray scale values and for computation of the related functions in the target area.The accuracy and sensitivity of gray evaluation and analysis of the related functions were compared in the detection of coagulative necrosis.Results Analysis of the related functions of the 120 samples showed an significantly higher accuracy(83.3%) than gray scale-based evaluation(68.3%) in detecting the coagulative necrosis(P<0.05).Under the same irradiation conditions,the mean values of the related function was significantly lower in microbubble group than in the control group(P<0.05).Conclusion Analysis of the related functions of the ultrasonographic data can be used to evaluate the coagulative necrosis in the target exposure area following HIFU with a greater sensitivity and accuracy than gray-scale evaluation.