Fig. 2.

A schematic representation of the risk score computation.

(A) is a schematic illustration of coronary artery tree model. Three marked lesions correspond to the vascular lesion (arrow) respectively in CCTA images(B). SIS was calculated by summation of the segments exhibiting plaque, i.e., the proximal right coronary artery (1) +proximal left circumflex artery (1) +middle left anterior descending artery (1). So, in this example, the segment involvement score is 3 out of a possible 16. Leiden score is calculated by summation of segment score quantified as plaque weight factor x stenosis weight factor x location weight factor, i.e., a right dominant system with a non-calcified plaque with <50% stenosis in the proximal right coronary artery(1 × 1.2 × 1)+ a calcified plaque with <50% stenosis in the proximal left circumflex artery(1.5 × 1.1 × 1)+ a mixed plaque with >50% stenosis in the middle left anterior descending artery(2.5 × 1.3 × 1.4), so the Leiden score is 7.4. CCTA = coronary computed tomography angiography; RCA = right coronary artery; LCX = left circumflex coronary artery; LAD = left anterior descending coronary artery.