Coronary artery calcium quantification with non-ECG-gated low-radiation dose CT of the chest

Objective: To evaluate the feasibility of quantifying coronary artery calcification in low radiation dose chest CT (LDCT) studies performed in an early lung cancer detection program by comparing the results of this technique with those of dedicated retrospectively ECG-gated cardiac CT. Material and methods: After obtaining informed consent, we evaluated the CT studies of 48 consecutive asymptomatic smokers (44 male, 4 female; mean age 59.7 years) included in an early lung cancer detection trial who underwent multislice LDCT (Volume Zoom, Siemens) of the chest and a retrospectively ECG-gated cardiac CT specifically dedicated to quantifying coronary artery calcification. LDCT examinations were reconstructed to reproduce cardiac CT parameters. Coronary calcium values were compared using the Wilcoxon signed-rank test. The concordance correlation coefficient (CCC) was calculated to determine the agreement between the two methods. Results: Coronary calcium values ranged from 0 to 1,908.4 (median: 89.6; IQR: 3.2; 227.4) in LDCT exams and from 0 to 1,486.6 (median: 81.3; IQR: 2.5; 316.4) in cardiac CT studies. No statistically significant difference was observed in the estimation of total coronary calcium score (p=0.28). The concordance between the two techniques was excellent (CCC >= 0.81). Conclusion: The LDCT study performed in lung cancer early detection trials enables coronary artery calcification to be quantified with the same accuracy as the dedicated retrospectively ECG-gated cardiac CT examination. (C) 2009 SERAM. Published by Elsevier Espana, S.L. All rights reserved.