Rationale and objectives: The aim of this study was to determine a more precise and accurate method of quantitating coronary artery calcium (CAC) detected with electron-beam computed tomography (CT) in patients with low CAC scores.
Materials and methods: Two 40-section, 3-mm-collimation, electrocardiographically gated electron-beam CT examinations of the heart were performed in each patient. Fifty patients with average scores between 2 and 100, as determined with the conventional scoring algorithm, were selected. The modified conventional scoring algorithm was compared with two techniques: calculated calcium volume and approximated calcium mass.
Results: The percentage difference between scans ranged from 37.2% for the conventional scoring method to 28.2% and 28.4% for volume- and mass-based methods, respectively. Increasing lesion size thresholds does not improve quantitative precision and reduces accuracy in patients with small amounts of CAC.
Conclusion: Quantification methods based on calcification volume or mass decrease score variation compared with the conventional scoring method, and increased size threshold does not improve accuracy.