改良甲状腺影像报告及数据系统在甲状腺髓样癌诊断中的价值

Value of modified TI-RADS in the diagnosis of medullary thyroid carcinoma

目的探讨改良的甲状腺影像报告及数据系统（TI－RADS）在甲状腺髓样癌（MTC）诊断中的价值，以及MTC与甲状腺乳头状癌（PTC）和良性结节的超声征象差异。方法回顾性分析术前超声检查且术后经病理证实的646例甲状腺结节患者，其中MTC 64例，PTC 414例，良性结节168例，分析其声像图特点，并采用改良的TI－RADS对病灶进行分级，分析其对MTC诊断的正确率及MTC的超声特点。结果改良TI－RADS诊断MTC的敏感度为87.5%，特异度为89.9%，阳性预测值为72.6%，阴性预测值为88.8%，正确率为67.2%。改良TI－RADS诊断PTC的敏感度为96.1%，特异度为59.5%，阳性预测值为85.4%，阴性预测值为86.2%，正确率为85.6%。不同医师的改良TI－RADS分级结果组内相关系数（ICC）为0.983。MTC多位于甲状腺腺体中上部（占85.9%，55/64），呈低－极低回声（占89.1%，57/64），边界相对光滑（占35.9%，23/64），纵横比多〈1（占53.1%，34/64），血流信号较丰富（占31.2%，20/64），容易发生颈部淋巴结转移（占51.6%，33/64），与PTC差异有统计学意义（P〈0.05）。结论改良TI－RADS诊断MTC的敏感度和正确率略低于PTC，其具有很高的重复性。MTC和PTC在结节位置、大小、内部回声、边界、纵横比、血流情况和淋巴结转移方面有一定差异。

Objective To investigate the value of modified thyroid imaging reporting and data system （TI-RADS） in the sonographic diagnosis of medullary thyroid carcinoma （MTC）, and to evaluate the sonographic differences among MTC, papillary thyroid carcinoma （PTC） and benign nodules in order to improve the ultrasound diagnostic accuracy of MTC. Methods 646 cases of thyroid lesions confirmed by pathology in our hospital were divided into the MTC group （64 cases）, PTC group （414 cases） and benign group （168 cases）. The ultrasonographic characteristics of these groups were retrospectively analyzed. All of the 646 cases were classified by modified TI-RADS grading criteria. The diagnostic accuracy of MTC and ultrasonic manifestations of MTC, PTC and benign nodular were assessed. Results The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of modified TI-RADS for MTC were 87.5%, 89.9%, 72.6%, 88.8%, and 67.2%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of modified TI-RADS for PTC were 96.1%, 59.5%, 85.4%, 86.2% and 85.6%. The intraclass correlation coefficient （ICC） of three different physicians for thyroid nodules was 0.983 by the modified TI-RADS. MTC were mostly located in middle and upper parts of the thyroid （85.9%, 55/64）, hypoechoic or extremely hypoechoic （89.1%, 57/64）, with relatively smooth margin （35.9%, 23/64） ,aspect ratio〈1 （53.1%,34/64）, abundant blood flow （31.2%,20/64）, and high lymph node metastasis rate （51.6%, 33/64）. These differences were statistically significant when compared to PTC （P〈 0.05）. Conclusions Repeatability of modified TI-RADS for MTC was high, and is slightly lower than that for PTC. MTC had specific features ： mostly located in middle and upper parts of the thyroid, hypoechoic or extremely hypoechoic, relatively smooth margin, aspect ratio〈 1, abundant blood flow and high lymph node metastasis rate.