Coronary artery calcium identified on non-gated chest computed tomography guides downstream coronary computed tomography angiography

Sep 30, 2026

Incidental coronary artery calcium (CAC) detected on non-gated chest computed tomography (CT) may influence which patients should proceed to coronary CT angiography (CTA). This retrospective study evaluated whether the severity of CAC on non-gated chest CT affects the diagnostic accuracy of coronary CTA for obstructive coronary artery disease (CAD) using invasive coronary angiography as reference. Among 337 patients, diagnostic performance declined with moderate-to-severe CAC, with severe CAC showing limited value, while CTA accuracy for stenosis assessment was reduced.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages11

Reading Time28 min

AccessFree to download

Introduction

Methods

Population

CAC assessment

Diagnostic accuracy evaluation

Results

Conclusions

Original Article Coronary artery calcium identified on non-gated chest computed tomography guides downstream coronary computed tomography angiography Anqi Yang1, Shuang Li1, Tian Ma1, Yinghao Xu2, Yi He1 1Department of Radiology, Beijing Friendship Hospital, Capital Medical University, Beijing, China; 2CT Business Unit, Canon Medical Systems (China) Co., Ltd., Beijing, China Contributions: (I) Conception and design: Y He, A Yang; (II) Administrative support: Y He, Y Xu, A Yang; (III) Provision of study materials or patients: A Yang; (IV) Collection and assembly of data: A Yang, T Ma; (V) Data analysis and interpretation: A Yang, S Li; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors. Correspondence to: Yi He, MD. Department of Radiology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xicheng District, Beijing 100050, [China. Email: heyi139@sina.com](China. Email: heyi139@sina.com). Background: The diagnostic accuracy of coronary computed tomography angiography (CTA) for obstructive coronary artery disease (CAD) is influenced by the extent of coronary artery calcium (CAC) . Incidental CAC findings on non-gated chest computed tomography (CT) may inform the selection of patients for subsequent coronary CTA. The purpose of this study was to evaluate how incidental CAC findings on non-gated chest CT affect the diagnostic accuracy of coronary CTA for obstructive CAD. Methods: We retrospectively identified consecutive patients who underwent coronary CTA. Cases who underwent both chest CT and invasive coronary angiography (ICA) within 1 year of the coronary CTA were included. The severity of CAC on non-gated chest CT was assessed using a semi-quantitative scoring system and classified into four scales (absent, mild, moderate, severe) . The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the diagnostic accuracy of coronary CTA compared to ICA. Subgroups were stratified based on the severity of CAC, and the accuracy of coronary CTA diagnosis in each subgroup was analyzed. Results: A total of 337 patients were included. The overall AUC of coronary CTA for diagnosing obstructive CAD was 0.609. In patients with absent or mild CAC, the AUC values were higher than the overall AUC (0.650 and 0.665, respectively) . In contrast, among patients with moderate or severe CAC, the AUC decreased to 0.549 and 0.491, respectively. Notably, in the severe CAC subgroup, the AUC fell below 0.5, indicating no diagnostic value. The proportion of obstructive CAD was significantly higher in the severe CAC subgroup compared to the other groups (P=0.004), and the negative predictive value of coronary CTA dropped to 0. Conclusions: In patients with severe CAC on non-gated chest CT, coronary CTA is less effective in providing accurate stenosis assessment. However, the cut-off values for semi-quantitative CAC scoring remain to be clearly defined through future studies. Keywords: Non-gated chest computed tomography (non-gated chest CT); coronary artery calcium (CAC); diagnostic accuracy; coronary computed tomography angiography (coronary CTA) Submitted Feb 06, 2025. Accepted for publication Oct 20, 2025. Published online Dec 31, 2025. doi: 10.21037/qims-2025-291 View this article at: [https://dx.doi.org/10.21037/qims-2025-291](https://dx.doi.org/10.21037/qims-2025-291) © AME Publishing Company. Quant Imaging Med Surg 2026;16(1):50 | [https://dx.doi.org/10.21037/qims-2025-291](https://dx.doi.org/10.21037/qims-2025-291) Page 2 of 11 Yang et al. CAC on non-gated CT guides coronary CTA Introduction Coronary artery calcium (CAC) is one of the most common incidental findings on non-gated chest computed tomography (CT) in patients imaged for noncardiac indications (1) . Some studies have reported that a CAC assessment with non-gated chest CT is reliable and has good agreement with Agatston scores from electrocardiograph

FAQs

What was the purpose of this study regarding CAC on non-gated chest CT?

To evaluate how incidental CAC findings on non-gated chest CT affect the diagnostic accuracy of downstream coronary CTA for obstructive CAD.

How were patients selected for the analysis?

Consecutive patients who underwent coronary CTA were retrospectively identified; cases with concurrent non-gated chest CT and invasive coronary angiography within 1 year of coronary CTA were included.

How did CAC severity on non-gated chest CT affect coronary CTA diagnostic performance?

Overall AUC was 0.609, but it was higher for absent or mild CAC (0.650 and 0.665) and decreased for moderate or severe CAC (0.549 and 0.491), with severe CAC falling below 0.5 and showing no diagnostic value.

Sep 30, 2026

Uploaded by วิน