Coronary Artery Calcium Scoring: Diagnostic Accuracy of Different Software Implementations

Purpose: To compare the diagnostic power of different software implementations for the quantification of coronary artery calcium. Materials and Methods: Electron beam computed tomography was performed in 109 heart transplant recipients at the same time as catheter coronary angiography and intracoronary ultrasound. Electron beam computed tomography images were analyzed by 3 software packages marketed for the quantification of coronary calcifications using the same software settings, and the resultant calcium scores correlated with the invasive reference methods by Bland-Altman plots and analysis of the receiver operating characteristics. Results: Although all scoring systems displayed close correlations upon regression analysis (r ² = 0.94-0.99), their ability to detect disease as per the invasive reference method varied significantly in some instances. The area under the ROC curve varied between Az = 0.78 and 0.85 for the detection of coronary artery stenosis upon coronary angiography (P = 0.05-0.13), and between Az = 0.75 and 0.83 for the detection of accelerated intimal proliferation (P = 0.03-0.18). Conclusions: Different software implementations for the quantification of coronary artery calcium load may display diagnostically relevant differences in spite of close direct correlation.