Contrast opacification difference of mural artery and the transluminal attenuation gradient on coronary computed tomography angiography for detection of systolic compression of myocardial bridge

Purpose Myocardial bridges (MB) have traditionally been considered a benign condition, but recent studies have demonstrated that the clinical complications can be dangerous. The transluminal attenuation gradient (TAG) obtained from coronary computed tomography angiography (CCTA) data (Retrospective ECG-triggered method) has been used in detecting significant stenosis in coronary artery caused by atherosclerosis. Contrast opacification difference (COD) was the parameters calculated as the change between attenuation of mural artery and the median attenuation of presumptive vessel segment; it was evaluated along with TAGstandardized (TAGs) and MB length for predicting MB with systolic compression (MB-SC) in patients diagnosed as MB in left anterior descending coronary artery (LAD) by CCTA or invasive coronary angiograph (ICA).