OBJECTIVES To identify the optimal method for evaluation of coronary artery calcium (CAC) severity on non-electrocardiogram-gated low-dose chest computed tomography (LDCT) in a nationwide lung cancer screening registry. METHODS A total of 256 subjects were retrospectively enrolled from participants of the Korean Lung Cancer Screening (K-LUCAS) project (an LDCT lung cancer screening registry for high-risk individuals). Four board-certified cardiothoracic radiologists independently assessed CAC severity using four different scoring methods (visual assessment, artery-based grading, segment-involvement grading, and segment-based grading) and classified severity for each case using all four methods as none, mild, moderate, or severe. Agreements between the four observers for CAC category classification and between the four different scoring methods for the same observer were assessed by Fleiss kappa statistics. Evaluation time for CAC grading was compared between observers and between grading methods. RESULTS Interobserver agreement was moderate for visual assessment (Fleiss kappa 0.451) and substantial for the other three methods (Fleiss kappa 0.673-0.704). Agreement between the four grading methods for the same observer was substantial for three observers (Fleiss kappa 0.610-0.705) and moderate for one (Fleiss kappa 0.578). Mean evaluation time differed significantly between methods (visual assessment, 14.3 ± 11.8 s; artery-based grading, 17.6 ± 22.3 s, segment-involvement grading, 19.2 ± 6.8 s; segment-based grading, 34.2 ± 37.4 s; p < 0.01). CONCLUSION Artery-based grading could be appropriate with substantial interobserver agreement and an acceptable mean evaluation time. KEY POINTS • CAC severity grading methods on LDCT show moderate to substantial agreements between grading methods and observers. • Artery-based grading could be appropriate with substantial interobserver agreement and a mean evaluation time of 17.6 s. • Visual assessment is disadvantaged by high interobserver variability despite having the shortest evaluation time.

中文翻译：

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非心电门控低剂量胸部计算机断层扫描对冠状动脉钙的严重程度分级：一项在全国肺癌筛查注册表中进行的多观察者研究。

目的在全国性肺癌筛查登记系统中，确定在非心电门控低剂量胸部计算机断层扫描（LDCT）上评估冠状动脉钙（CAC）严重程度的最佳方法。方法从韩国肺癌筛查（K-LUCAS）项目（针对高危人群的LDCT肺癌筛查注册表）的参与者中回顾性纳入了256名受试者。四名获得董事会认证的心胸放射科医生使用四种不同的评分方法（视觉评估，基于动脉的分级，涉及部分的分级和基于部分的分级）独立评估了CAC严重性，并使用所有四种方法对每种情况的严重性进行了分类，分别为无，轻度，中度或严重。通过Fleiss kappa统计数据评估了四位CAC类别分类的观察者之间以及同一位观察者的四种不同评分方法之间的协议。在观察者之间和分级方法之间比较了CAC分级的评估时间。结果观察者之间的协议对视觉评估的评价是中等的（Fleiss kappa为0.451），对于其他三种方法的一致性（Fleiss kappa为0.673-0.704），该协议的要求是中等的。同一观察者的四种评分方法之间的一致性对于三位观察者（Fleiss kappa 0.610-0.705）是实质性的，而对于一位观察者（Fleiss kappa 0.578）是适度的。两种方法之间的平均评估时间差异显着（视觉评估为14.3±11.8 s;基于动脉的评分为17.6±22.3 s，涉及段的评分为19.2±6.8 s;基于段的评分为34.2±37.4 s; p <0.01） 。结论在观察者之间达成一致并接受可接受的平均评估时间的前提下，基于动脉的分级可能是合适的。要点•LDCT上的CAC严重性分级方法显示出分级方法与观察者之间的中度到实质性一致。•在观察者之间达成一致并平均评估时间为17.6 s的情况下，基于动脉的分级可能是合适的。•尽管评估时间最短，但观察者之间的差异很大，因此视觉评估不利。6秒 •尽管评估时间最短，但观察者之间的差异很大，因此视觉评估不利。6秒 •尽管评估时间最短，但观察者之间的差异很大，因此视觉评估不利。