Coronary Calcium Measurements by Double Helical Computed Tomography

RATIONALE AND OBJECTIVES: Coronary calcium (CC) measured by fast computed tomography (CT) was proposed recently as a noninvasive method of monitoring the coronary atherosclerotic process. Assessment of the reproducibility of CC measurements (mainly interstudy variability) is essential for consistent interpretation of serial studies. METHODS: The authors scanned 74 patients (50 men and 24 women) twice on the same day to determine the interstudy variability of a new scoring algorithm, using the average instead of conventional peak CT density values. RESULTS: Nineteen patients had no calcium on either scan. In the remaining 55 patients, interstudy variability was decreased by 31% using the average algorithm (32%-23%; P < 0.001). CONCLUSIONS: Using the average instead of conventional peak density score provides better reproducible measurements of calcium by double helical CT.