探讨18 MHz高频线阵探头与常规高频探头诊断甲状腺癌侵犯前方被膜的应用价值。

选取2015年12月至2016年3月在北京协和医院就诊的甲状腺癌患者68例，共73个病灶，分别采用常规高频线阵探头与18 MHz高频线阵探头对病灶进行观察，以病理为"金标准"，评估2种探头诊断甲状腺癌侵犯前方被膜的准确性及预测价值。采用Kappa检验分析采用2种不同频率的探头诊断与病理结果判断的一致性。采用受试者工作特征（ROC）曲线分析在2种判断标准下分别采用2种不同频率的探头对甲状腺癌侵犯前方被膜的诊断准确性。

（1）以肿瘤紧邻被膜且不论有无被膜回声中断作为甲状腺癌侵犯前方被膜的判断标准，采用18 MHz高频探头对有无被膜侵犯与病理结果判断的一致性较好（Kappa值=0.803，P<0.01），其诊断特异度、阳性预测值及准确性均优于常规高频探头（90.7% vs 69.8%，87.1% vs 68.3%，90.4% vs 79.5%），在此判断标准下采用18 MHz高频探头，其ROC曲线下面积（0.903）高于常规高频探头ROC曲线下面积（0.816），表明前者诊断准确性较高。（2）以肿瘤前方甲状腺被膜回声连续性中断作为判断标准时，18 MHz高频探头与常规高频探头诊断甲状腺癌有无侵犯被膜与病理结果判断的一致性一般（Kappa值=0.677、0.518，P均<0.01），常规高频探头诊断的敏感度、阳性预测值、阴性预测值、准确性均低于18 MHz高频线阵探头（53.3% vs 70.0%，74.5% vs 82.0%，88.9% vs 91.3%，78.1% vs 84.9%）。

18 MHz高频探头在准确判断甲状腺癌与前方被膜之间的关系以及有无前方被膜侵犯方面有较高的应用价值，有助于甲状腺癌分期及预后的判断。

To investigate the value of 18 MHz high-frequency linear array ultrasound probe in the diagnosis of thyroid anterior capsular invasion, and compare it with the conventional high-frequency ultrasound probe.

Seventy-three nodules in 68 patients in Peking Union Medical College Hospital from December 2015 to March 2016 underwent conventional and 18 MHz high-frequency probes examination before operation and were compared with pathological results. The accuracy, sensitivity and specificity of the 18 MHz high-frequency linear array probe and the conventional high-frequency probe were determined. The consistency between the gold standard and the diagnosis by using two different frequency probes was measured using Kappa statistics. Additionally, diagnostic accuracy of different frequency probes was further evaluated according to the area under the ROC curve.

The diagnostic consistency test of the total sample of 73 nodules: ″capsular abutment″ as the diagnostic criterion, the diagnostic consistency of 18MHz high-frequency probe was good (Kappa=0.803, P<0.01). The specificity, positive predictive value and accuracy were superior to the conventional high-frequency probe (90.7% vs 69.8%, 87.1% vs 68.3%, 90.4% vs 79.5%). The area under the ROC curve was 0.903, higher than that of the conventional high-frequency probe (0.816), which demonstrated that the former had better diagnostic accuracy. If ″the disruption of the perithyroidal echogenic line″ as another diagnostic criterion, the diagnostic consistency of the 18 MHz and conventional high-frequency probe was general, the Kappa value were 0.677 and 0.518. The sensitivity, positive predictive value, negative predictive value and accuracy of conventional high-frequency probe were inferior to the 18 MHz high-frequency probe (53.3% vs 70.0%, 74.5% vs 82.0%, 88.9% vs 91.3%, 78.1% vs 84.9%).

The 18 MHz high frequency probe is a feasible tool for accurate prediction of the distance between tumor and thyroid anterior capsular and anterior capsular invasion, and it is helpful for the diagnosis of the preoperative staging and the prognosis of PTC.