CORONARY CALCIUM MEASUREMENTS BY DOUBLE-HELICAL COMPUTED-TOMOGRAPHY -USING THE AVERAGE INSTEAD OF PEAK DENSITY ALGORITHM IMPROVES REPRODUCIBILITY

RATIONALE AND OBJECTIVES. Coronary calcium (CC) measured by fast compu ted tomography (CT) was proposed recently as a noninvasive method of m onitoring the coronary atherosclerotic process, Assessment of the repr oducibility of CC measurements (mainly interstudy variability) is esse ntial for consistent interpretation of serial studies. METHODS. The au thors scanned 74 patients (50 men and 24 women) twice on the same day to determine the interstudy variability of a new scoring algorithm, us ing the average instead of conventional peak CT density values. RESULT S. Nineteen patients had no calcium on either scan. In the remaining 5 5 patients, interstudy variability was decreased by 31% using the aver age algorithm (32%-23%; P < 0.001). CONCLUSIONS. Using the average ins tead of conventional peak density score provides better reproducible m easurements of calcium by double helical CT.