Endocrinology and Metabolism Clinic, Bugat Hospital, Gyöngyös, Hungary.
Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
Eur Thyroid J. 2023 Mar 15;12(2). doi: 10.1530/ETJ-22-0134. Print 2023 Apr 1.
Thyroid nodule ultrasound characteristics are used as an indication for fine-needle aspiration cytology, usually as the basis for Thyroid Imaging Reporting and Data System (TIRADS) score calculation. Few studies on interobserver variation are available, all of which are based on analysis of preselected still ultrasound images and often lack surgical confirmation.
After the blinded online evaluation of video recordings of the ultrasound examinations of 47 consecutive malignant and 76 consecutive benign thyroid lesions, 7 experts from 7 thyroid centers answered 17 TIRADS-related questions. Surgical histology was the reference standard. Interobserver variations of each ultrasound characteristic were compared using Gwet's AC1 inter-rater coefficients; higher values mean better concordance, the maximum being 1.0.
On a scale from 0.0 to 1.0, the Gwet's AC1 values were 0.34, 0.53, 0.72, and 0.79 for the four most important features in decision-making, i.e. irregular margins, microcalcifications, echogenicity, and extrathyroidal extension, respectively. The concordance in the discrimination between mildly/moderately and very hypoechogenic nodules was 0.17. The smaller the nodule size the better the agreement in echogenicity, and the larger the nodule size the better the agreement on the presence of microcalcifications. Extrathyroidal extension was correctly identified in just 45.8% of the cases.
Examination of video recordings, closely simulating the real-world situation, revealed substantial interobserver variation in the interpretation of each of the four most important ultrasound characteristics. In view of the importance for the management of thyroid nodules, unambiguous and widely accepted definitions of each nodule characteristic are warranted, although it remains to be investigated whether this diminishes observer variation.
甲状腺结节的超声特征被用作细针穿刺细胞学检查的指征，通常作为甲状腺影像报告和数据系统（TIRADS）评分计算的基础。关于观察者间变异的研究很少，这些研究都是基于对预选的超声静态图像的分析，而且往往缺乏手术证实。
在对 47 例恶性和 76 例良性甲状腺病变的超声检查视频记录进行盲法在线评估后，来自 7 个甲状腺中心的 7 名专家回答了 17 个与 TIRADS 相关的问题。手术组织学是参考标准。使用 Gwet 的 AC1 组内相关系数比较每个超声特征的观察者间差异；值越高表示一致性越好，最大值为 1.0。
在 0.0 到 1.0 的范围内，四个最重要的决策特征（即不规则边缘、微钙化、回声和甲状腺外延伸）的 Gwet 的 AC1 值分别为 0.34、0.53、0.72 和 0.79。在轻度/中度和非常低回声结节之间的区分上，一致性为 0.17。结节越小，在回声方面的一致性越好，结节越大，在微钙化存在方面的一致性越好。只有 45.8%的病例正确识别了甲状腺外延伸。
对视频记录的检查，紧密模拟了真实世界的情况，揭示了在解释四个最重要的超声特征中的每一个特征时存在大量的观察者间变异。鉴于这些特征对甲状腺结节的管理非常重要，有必要对每个结节特征进行明确和广泛接受的定义，尽管仍需研究这种定义是否会减少观察者的变异。
