相关函数应用于HIFU辐照兔VX2乳腺肿瘤的监控声像图研究

摘要

目的 探讨在高强度聚焦超声(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.rn方法 120只兔VX2乳腺移植性肿瘤随机分为4组,在相同辐照时间、不同辐照强度下,采用HIFU定点辐照,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,用支持向量机(support vector machine,SVM)筛选参数得到其最佳决策超平面.rn结果 监控声像图相关函数处理可以评价HIFU辐照组织的凝固性坏死情况,其灵敏度高于用声像图灰度评价(P＜0.05).rn结论 声像图相关函数判断HIFU辐照的靶组织有无凝固性坏死比灰度评价更为准确可靠.%Objective To improve the determination sensitivity of coagulation necrosis caused by high intensity focused ultrasound (HIFU) exposure. Methods 120 rabbits implanted VX2 Breast Neoplasms were divided into 4 groups randomly and were dot-exposed with HIFU with constant setting of intensity, duration series and depth. The ultrasonographys generated at two time points were inspected, I. E. Prior to the exposure and instantaneous after the exposure . The gray values of the graphs were measured, and the correlation of the target area was computed. Based on Support Vector Machine, our method automatically selects the best parameters for the determination function. Results The correlation coefficients between ultrasound-image (before and after the exposure) can be used to predict HIFU coagulation necrosis, and its sensitivity is higher than the gray-scale method over ultrasonography monitoring (P<0. 05). Conclusions Correlation analysis over ultrasonographic data can be used to predict coagulation necrosis of target tissues exposed with HIFU. According to experiments, our method is more reliable than traditional gray-scale evaluation method.