超声弹性成像对甲状腺微小结节良恶性诊断的应用价值

Value of ultrasound elastography in the diagnosis of malignant and benign micro-lesions of thyroid

目的分析甲状腺微小癌和甲状腺微小良性结节性病变高频超声及超声弹性成像的声像图特征。评价比较高频超声及超声弹性成像对甲状腺微小结节良恶性的诊断价值。方法分析经病理证实的89例患者,共161个长径在2~10 mm的甲状腺微小结节的高频超声和超声弹性成像声像图特征,记录结节的高频超声表现及结节的弹性评分、弹性应变率比值（SR）值,并对结节的高频超声特征给予赋值,通过受试者操作特性曲线（ROC）来评价高频超声及超声弹性成像技术对甲状腺微小结节良恶性鉴别诊断的能力。结果弹性评分法及SR法诊断甲状腺良、恶性结节的曲线下的面积分别为0.885、0.916;诊断临界点弹性评分〉3分、SR〉4.15。弹性评分的敏感性、特异性分别为85.4%、82.6%;SR的敏感性、特异性分别为93.3%、87.3%。常规高频超声诊断甲状腺良、恶性结节的曲线下的面积为0.850,诊断临界点为5分,其敏感性、特异性分别为78%、82.6%。两两比较差异有统计学意义（P〈0.05）。对于最大长径≤5 mm的甲状腺微小病变,超声弹性成像（弹性评分和SR值）的诊断准确度分别为83.3%、85.7%;高于常规高频超声（73.8%）,但超声弹性成像与常规高频超声差异无统计学意义（P〉0.05）。结论超声弹性成像在甲状腺微小病变的良恶性鉴别诊断中具有重要价值。

Objective To investigate the diagnostic value of ultrasound elastograghy in the thyroid micro-lesions. Methods The sonography features of 161 lesions of thyroid micro-nodules with diameters range from 2 to 10 mm in 89 patients were analyzed. The final diagnosis was confirmed by pathological examinations of surgical samples. Receiver-operating characteristic curve（ROC） analyses was performed to assess the diagnostic performance. The areas under ROC curve of two-dimensional ultrasound and the elastic grade of and SR were compared. P〈0.05 were considered to be statistically significant. Results The sensitivity, specificity of SR and elastic grade in differentiating between malignant and benign micro-lesions were 93.3%, 87.3% and 85.4%, 82.6%, respectively. The best cut-off points of the two methods were 4.15 and 3, respectively. ROC analyses indicated that the area under the curve was 0.916 for SR and 0.885 for the elastic grade. There was significant difference between the two methods. The sensitivity, specificity of US in differentiating between malignant and benign micro-lesions were 78%, 82.6% based on the cut-off point of 5. ROC analyses indicated that the area under the curve was 0.916, significantly lower than that of the SR and elastic score. Although the accuracy of ultrasound elastography was higher than that of high frequency ultrasound in the diagnosis of TMC range from 2 to 5 mm, the difference wasn＇t statistically different（P〈0.05）. Conclusions Ultrasound elastography has high value in differential diagnosis of malignant and benign micro-lesion of thyroid.