Coronary Calcium Scoring as Prediction of Coronary Artery Diseases with Low-Dose Dual-Source CT

The aim of this paper is to evaluate the correlation between the coronary calcium score (CCS) and coronary artery disease (CAD), patients underwent coronary CT angiography (CTA). Four hundred and five patients who underwent a coronary CT with CCS analysis were considered for this retrospective study. Coronary CTA was performed using a dual-source (256-slice) CT scanner (SOMATOM Definition Flash, Siemens Healthcare, Forchheim, Germany). Before injecting the contrast medium, non-contrasted cardiac CT was performed in a longitudinal scan field from the tracheal carina down to the diaphragm. The corresponding images for calcium scoring were reconstructed with a slice width of 1.5 mm and a slice interval of 1 mm, and the tube voltage was 120 kVp. The total calcium score was calculated using dedicated software. The calcium score based on the Agatston method was defined as the presence of a lesion with an area greater than 1 mm2 and peak intensity greater than 130 Hounsfield Units, which was automatically identified and marked with color by the software. From the radiological report, the degree of coronary stenosis was retrieved. A score of 1 corresponds to the absence of stenosis, a score of 2 to mild stenosis (<50%), and a score of 3 to moderate/severe stenosis (>50%). The total coronary gravity score (CGS) for each patient was calculated by summing the score of each coronary artery. The Spearman test was used for correlation. Out of the 405 patients, 217 were male. The mean and standard deviation age was 72 ± 11 years. The overall amount of calcium was an Agatston score of 393 ± 709. A positive correlation between CCS and CGS was found (r = 0.835 and p < 0.001). A ROC curve with AUC 0.917 (p ≤ 0.001) was obtained. The optimal cutoff point of the calcium score for discriminating CGS < 2 was 112, yielding sensitivity of 90% and specificity of 81%. This study confirms the important relationship between the coronary artery calcium score and the presence and extension of coronary artery disease.