探讨中国甲状腺超声报告与数据系统（C-TIRADS）在不同大小甲状腺结节中的诊断价值。

前瞻性选取2020年12月至2022年12月经手术病理证实的甲状腺结节患者1146例，共1247个结节，按结节的最大径将其分为A₁组（＜10 mm）、A₂组（10~20 mm）和A₃组（＞20 mm），评估各组甲状腺结节的超声特征，并根据C-TIRADS对其进行评分和分类。采用MannWhitney U检验比较各组良恶性结节C-TIRADS评分的差异，根据病理结果构建各组C-TIRADS评分和分类诊断结节良恶性的受试者操作特征（ROC）曲线，确定最佳临界值，分析C-TIRADS对不同大小甲状腺结节良恶性的诊断效能。

A₁组良恶性结节的评分分别为2（1，3）分、3（2，3）分，A₂组良恶性结节的评分分别为1（0，2）分、3（3，4）分，A₃组良恶性结节的评分分别为0（0，1）分、3（2，3）分，各组甲状腺恶性结节的评分均高于良性结节，差异均具有统计学意义（Z=3.501、15.273、10.012，P均＜0.001）。A₁组、A₂组和A₃组C-TIRADS评分系统对应的ROC曲线下面积（AUC）分别为0.580、0.893和0.918，临界值分别为＞2分、＞1分和＞1分，3组分类系统对应的AUC分别为0.625、0.877、0.918，临界值分别为＞4B类、＞4A类、＞4A类。3组评分和分类的诊断敏感度和特异度一致，且随着结节直径的增加，敏感度逐渐降低，分别为96.43%、93.86%、77.17%，特异度逐渐增加，分别为30.64%、69.90%、94.12%。

C-TIRADS对不同大小甲状腺结节的诊断效能有所不同，随着结节的增大，C-TIRADS对甲状腺结节的诊断价值也逐渐升高。

To assess the diagnostic value of the Chinese thyroid imaging reporting and data system (C-TIRADS) in thyroid nodules with different sizes.

A total of 1 146 patients with 1 247 thyroid nodules confirmed by surgical pathology were prospectively selected from December 2020 to December 2022. According to the maximum diameter of thyroid nodules measured by ultrasound, all the thyroid nodules were divided into A₁ group (＜10 mm), A₂ group (10-20 mm), and A₃ group (＞20 mm). According to the C-TIRADS, the ultrasonic characteristics of thyroid nodules in each group were evaluated and scored. The Mann-Whitney U-test was used to compare the C-TIRADS scores of benign and malignant nodules among the groups. Receiver oeprating characteristic (ROC) analysis was performed to obtain the optimal cut-off values for scoring and classification. The diagnostic efficacy of C-TIRADS scoring and classification for thyroid nodules of different sizes was then analyzed.

The scores of benign and malignant nodules were 2 (1, 3) and 3 (2, 3) in group A₁, 1 (0, 2) and 3 (3, 4) in group A₂, and 0 (0, 1) and 3 (2, 3) in group A₃, respectively. The scores of thyroid malignant nodules in each group were significantly higher than those of benign nodules (Z=3.501, 15.273, and 10.012, respectively, P＜0.001 for all). The area under the curve (AUC) of C-TIRADS scoring in groups A₁, A₂, and A₃ was 0.580, 0.893, and 0.918, respectively, and the cut-off value was >2, >1, and >1, respectively. The AUC of C-TIRADS classification was 0.625, 0.877, and 0.918, respectively, and the cut-off value was >4B, >4A, and >4A, respectively. The corresponding sensitivity and specificity were consistent among the three groups, and as the diameter of the nodule increased, the sensitivity gradually decreased (96.43%, 93.86%, and 77.17%, respectively) and the specificity gradually increased (30.64%, 69.90%, and 94.12%, respectively).

C-TIRADS has different diagnostic value for thyroid nodules with different sizes. As the diameter of thyroid nodules increases, the diagnostic value of C-TIRADS for thyroid nodules increases as well.