Purpose: Coronary artery calcium (CAC) measurement has been utilized as an important indicator of coronary artery disease and predictor of cardiovascular risk. The reproducibility of CAC measurements makes it clinically useful for the assessment of progression and regression of coronary atherosclerosis. This study assessed the reproducibility of the Agatston CAC score among patients undergoing 256-slice multidetector computed tomography (MDCT) scans using 0.8-mm slice thickness.
Materials and methods: One hundred four patients (aged 62.8 ± 9.0 years, 56.7 % males) with CAC scores >0 on 256-slice MDCT underwent additional MDCT imaging at 2-week intervals. The CAC score was quantified using the Agatston score, which was measured independently by two radiologists.
Results: The variability between observers and MDCT scan measurements was determined by the mean value of absolute and percentage differences: inter-scan/inter-observer (14.45 ± 21.84, 12.51 ± 21.84 %), intra-scan/intra-observer (1.75 ± 5.85, 1.26 ± 3.69 %), intra-scan/inter-observer (3.3 ± 9.1, 4.8 ± 21.3 %), and inter-scan/intra-observer (13.45 ± 20.7, 10.04 ± 10.46 %).
Conclusion: Reproducibility in CAC measurements using the 0.8-mm-thickness 256-slice MDCT showed low inter-scan/inter-observer variability. Therefore, this CT imaging has potential to be used in prospective, longitudinal CAC assessments.