超声造影联合弹性成像对甲状腺影像报告和数据系统4类甲状腺结节的诊断价值

Value of contrast enhanced ultrasound combined with elastography in differential diagnosis of thyroid imaging reporting and data system 4 thyroid nodules

目的探讨超声造影、弹性成像单独及二者联合对甲状腺影像报告和数据系统(TI-RADS)4类结节的诊断价值。方法收集2011年11月至2016年8月在首都医科大学宣武医院行常规超声检查,且分类为TI-RADS 4类的137例甲状腺结节患者共159个结节,分别行超声造影及弹性成像检查,以术后病理结果为"金标准",建立超声造影及二者联合诊断甲状腺结节的多因素Logistic回归方程,采用受试者工作特征(ROC)曲线比较超声造影、弹性成像及二者联合的诊断价值。得出超声造影、弹性成像及联合诊断的敏感度、特异度、准确度、阳性预测值、阴性预测值及漏诊率。结果甲状腺恶性结节患者的超声造影特征多表现为:低增强、不均匀性增强、不完全或无环状增强及达峰时间晚于周边组织,差异均有统计学意义(χ2=24.378、69.194、29.434、7.375,P均<0.01)。联合诊断时,增强均匀度、有无环状增强及弹性评分进入Logistic回归方程,是诊断结节的独立指标。联合诊断的ROC曲线下面积(0.921±0.023),大于超声造影和弹性成像单独诊断的ROC曲线下面积(分别为0.88±0.029、0.80±0.038)。联合诊断有较高的敏感度、准确度、阴性预测值及较低的漏诊率(分别为92.1%、86.2%、84.6%与7.9%)。结论超声造影联合弹性成像可显著提高TI-RADS4类甲状腺结节的诊断效能,有较高的临床应用价值。

Objective To assess the diagnostic value of contrast enhanced ultrasound （CEUS）, elastography and their combined use in diagnosing thyroid nodules of thyroid imaging reporting and data system （TI-RADS） 4. Methods From November 2011 to August 2016, 159 TI-RADS 4 nodules diagnosed by conventional ultrasound were prospectively enrolled and examined by CEUS and elastography before surgery. Multivariate logistic regression models were established for CEUS and CEUS combined with elastography to diagnose thyroid malignancy. The diagnostic performances of CEUS, elastography and their combined use were evaluated with the receiver operating characteristic （ROC） curve, The sensitivity, specificity, accuracy, positive predictive value, negative predictive value and omission diagnostic rate of CEUS, elastography and their combined use were compared by Chi-square test. Results The CEUS features significantly predicting malignancy were heterogeneous enhancement, hypoenhancement, without or incomplete ring-enhancement and later time to peak than the surrounding parenchyma （χ^2=24.378, 69.194, 29.434 and 7.375, all P 〈 0.01）. Furthermore, the multivariate logistic regression for CEUS combined with elastography showed that heterogeneous enhancement, ring enhancement and elasticity score were the independent predictors of thyroid malignancy. The area under the ROC curve of CEUS combined with elastography was （0.921±0.023） which was higher than that of CEUS and elatography （0.88±0.029 and 0.80±0.038, respectively; both P 〈 0.05）. Moreover, the sensitivity, accuracy and negative predictive value of CEUS combined with elastography were 92.1%, 86.2% and 84.6%, respectively. The omission diagnostic rate of CEUS combined with elastography （7.9%） was reduced. And the diagnostic accuracy of CEUS combined with elastography was significantly higher than that of CEUS and elastography （P 〈 0.05）. While the diagnostic accuracy of CEUS was close to the elastography, the difference was not statistically significant （P 〉 0.05）. Conclusion The diagnostic value of CEUS combined with elastography was remarkably significant in the differential diagnosis of TI-RADS 4 nodules.