Tamura纹理分析在声像图监控HIFU消融兔VX2乳腺肿瘤中的应用

Application of Tamura texture analysis in monitoring HIFU ablation of rabbit VX2 breast tumor

目的探讨Tamura纹理参数对声像图监控高强度聚焦超声(HIFU)辐照下靶组织凝固性坏死情况的评价效果。方法根据HIFU辐照兔VX2乳腺肿瘤的辐照强度,将120只新西兰白兔随机分为90W、120W、150W组,每组40只,辐照时间均为3s。采集辐照前和辐照后即刻的声像图,提取Tamura纹理参数中的方向度、粗糙度和对比度;通过支撑适量机筛选,获得决策超平面,并对结果进行分析。结果 Tamura判断凝固性坏死的敏感度为89.71%(61/68),特异度为69.23%(36/52),准确率为80.83%(97/120);灰度判断凝固性坏死的敏感度为57.35%(39/68),特异度为63.46%(33/52),准确率为60.00%(72/120),前者的敏感度和准确率均明显高于后者(P均<0.001)。90 W组中,Tamura判断凝固性坏死的准确率为77.50%(31/40),高于灰度(20/40,50.00%,P=0.011);120 W组中,Tamura判断凝固性坏死的准确率为80.00%(32/40),高于灰度(22/40,55.00%,P=0.017)。结论声像图Tamura纹理分析判断凝固性坏死是可行的,且较之灰度具有一定优越性。

Objective To evaluate Tamura texture parameters in judging the coagulative necrosis of target tissues under the treatment of the high intensity focused ultrasound （HIFU）. Methods Totally 120 New Zealand rabbits were randomly divided into 3 groups according to different irradiation intensities of HIFU for 3 s targeted on the VX2 breast tumors of the rabbits, i.e. 90 W group （n=40）, 120 W group （n=40） and 150 W group （n=40）. The ultrasonography obtained before and immediately after irradiation and 3 eigenvalues of Tamura texture parameters （directionality, roughness and contrast） were extracted. By selecting these obtained parameters through a support vector machine, the data were analyzed. Results The sensitivity, specificity and accuracy rate of Tamura texture analyses was 89.71% （61/68）, 69.23% （36/52） and 80.83% （97/120）, of gray was 57.35% （39/68）, 63.46% （33/52） and 60.00% （72/120）. The sensitivity and accuracy rate of the former were higher than those of the latter （both P〈0.001）. The accuracy rate of Tamura texture analyses in 90 W group and 120 W were higher than that of gray. Conclusion With more advantages than gray evaluation, Tamura texture analysis is applicable for the judgment of coagulative necrosis.