CORONARY-ARTERY CALCIUM - ALTERNATE METHODS FOR ACCURATE AND REPRODUCIBLE QUANTITATION

Rationale and Objectives. The aim of this study was to determine a mor e 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-coll imation, electrocardiographically gated electron-beam CT examinations of the heart were performed in each patient. Fifty patients with avera ge scores between 2 and 100, as determined with the conventional scori ng algorithm, were selected. The modified conventional scoring algorit hm was compared with two techniques: calculated calcium volume and app roximated calcium mass. Results. The percentage difference between sca ns ranged from 37.2% for the conventional scoring method to 28.2% and 28.4% for volume- and mass-based methods, respectively. Increasing les ion size thresholds does not improve quantitative precision and reduce s accuracy in patients with small amounts of CAC. Conclusion. Quantifi cation methods based on calcification volume or mass decrease score va riation compared with the conventional scoring method, and increased s ize threshold does not improve accuracy.