A Modified Length-Based Grading Method for Assessing Coronary Artery Calcium Severity on Non-Electrocardiogram-Gated...

Area of Science:

• Radiology
• Cardiovascular Imaging
• Medical Diagnostics

Background:

• Coronary artery calcium (CAC) scoring is crucial for cardiovascular risk assessment.
• Non-electrocardiogram (ECG)-gated chest computed tomography (CT) is widely available but assessing CAC severity can be challenging.
• Standardized and reliable methods for CAC assessment on non-ECG-gated CT are needed.

Purpose of the Study:

• To validate a simplified ordinal scoring method, modified length-based grading, for assessing CAC severity.
• To compare the performance of modified length-based grading against visual assessment on non-ECG-gated chest CT.
• To evaluate the agreement of these methods with the Agatston score on ECG-gated cardiac CT.

Main Methods:

• Retrospective analysis of 120 patients who underwent both non-ECG-gated chest CT and ECG-gated cardiac CT.
• Six radiologists independently assessed CAC severity using visual assessment and modified length-based grading on chest CT.
• CAC categories were compared to the reference standard Agatston score on cardiac CT.
• Interobserver agreement (Fleiss kappa) and agreement with the reference standard (Cohen's kappa) were calculated.
• Time taken for grading was also compared between methods.

Main Results:

• Modified length-based grading showed good interobserver agreement (Fleiss kappa, 0.695), superior to visual assessment (Fleiss kappa, 0.553).
• Modified length-based grading demonstrated better agreement with the Agatston score (Cohen's kappa, 0.695) than visual assessment (Cohen's kappa, 0.565).
• Visual assessment was slightly faster (41.8 s) than modified length-based grading (43.5 s), but this difference was not clinically significant (P < 0.001).

Conclusions:

• Modified length-based grading is a reliable method for assessing CAC severity on non-ECG-gated chest CT.
• This simplified grading method offers improved interobserver agreement and better concordance with established cardiac CT scoring.
• It provides a valuable alternative for routine CAC assessment in clinical practice.