超声弹性应变率值在甲状腺良恶性结节诊断中的应用

目的探讨超声实时弹性成像及超声弹性应变率值在甲状腺良恶性结节诊断中的最佳诊断界点及其在甲状腺良恶性结节鉴别诊断中的应用价值。方法对64例患者二维超声检出的91个甲状腺结节行超声弹性成像检查及应变率值测量;依据病理诊断结果对良性与恶性甲状腺结节予以弹性分级与分组;以Ⅲ级为界:0～Ⅱ级诊断为良性,Ⅲ～Ⅳ级诊断为恶性。结果 (1)超声弹性分级诊断:64例91个甲状腺结节术前超声弹性分级诊断为0～Ⅱ级45个结节(良性组),弹性分级诊断与病理诊断符合43个结节(43/64,67.2%);弹性分级诊断为Ⅲ、Ⅳ级46个结节,弹性分级诊断与病理诊断符合25个结节(25/27,92.6%);(2)超声应变率值测量:91个结节中67个结节应变率值5.525,24个结节应变率值≥5.525;恶性组结节应变率值均值(7.38±3.72),高于良性组(2.64±1.32,P0.05);(3)应变率值最佳临界点:通过ROC曲线确定的弹性应变率值最佳诊断界点为5.525,约登指数0.78,以超声弹性应变率值5.525为最佳诊断界点,检出良性组中62个结节(62/64)与病理诊断符合;以超声弹性应变率值≥5.525为最佳诊断界点,检出恶性组中22个结节(22/27)与病理诊断符合,对应的敏感性为81.5%,特异性为96.8%;(4)甲状腺结节良恶性鉴别:应变率值ROC曲线下面积0.892大于弹性分级法0.799,应变率值准确性92.3%高于弹性分级法的74.7%。结论超声弹性成像应变率值可用于甲状腺结节良恶性的判断,为甲状腺弹性成像检查提供了一项新的诊断指标。

The application of strain ratio for ultrasonic elastography in diagnosis of benign and malignant thyroid nodules

Objective To evaluate the clinical value of elasticity score and strain ratio by ultrasonography in differential diagnosis of thyroid nodules and the cut-off point of strain ratio for thyroid nodules. Methods Elasticity imaging was used to examine 64 cases of patient with 91 thyroid nodules. The elasticity scores and strain ratio were retrospectively reviewed and compared with pathology. The elasticity grades 0- II was predict of benign, grades III-IV was predict of malignant. Results （ 1 ） An elasticity score of 0- II was observed in 45 of 91 nodules in 45 cases , while a score of III-IV in the rest of 46 nodules. An elasticity score of 0- II was observed in 43 of 64 benign nodules, while a score of III-IV in 25 of 27 malignant nodules ; Elasticity score 0-II were observed in the majority of benign nodules, while score III-IV in the majority of malignant nodules. （2）67 nodules 〈 5. 525, 24 nodules ≥ 5. 525 in elastic strain ratio. The mean of elastic strain ratio of 7.38 ± 3.72 was statistically higher in 27 malignant nodules that of 2.64 ± 1.32 in 64 of benign nodules（ P 〈 0.05 ）. （3）According to ROC analysis, the cut off point of strain ratio was determined as 5. 525, Youden＇ s index was 0.78, 62 nodules with elastic strain ratio 〈 5. 525 were confirmed as benign by pathology, 22 nodules with elastic strain ratio≥5. 525 were confirmed as malignant by pathology, sensitivity was 81.5 % and specificity was 96.8%. （4）The diagnostic accuracy of the strain ratio was superior to that of elasticity score. Conclusion The strain ratio and elasticity score in elasticity images is helpful in the differential diagnosis of thyroid lesions.