Objective: To assess the ability to detect myocardial bridging (MB) of dual-source computed tomography (DSCT) compared with conventional coronary angiography (CAG).
Methods: Both DSCT coronary angiography (DSCTCA) and CAG were performed on 53 patients diagnosed or suspected as with coronary artery disease (CAD), 45 males and 8 females, aged 36-87. 4D cine mode was performed on 16 of these 53 patients with MB shown on DSCTCA, and the CAG data were reviewed retrospectively by automatic cine method. The MB findings by both methods were compared. The diameters of segments proximal to and distal to MB, tunneled coronary arteries at systolic and diastolic phases were measured, and stenosis rate of tunneled coronary arteries was computed according to the equation. The relationship between stenosis rate of tunneled artery and milking effect on 4D cine mode was analyzed.
Results: Of the 53 patients who had undergone CAG; 4 images of MB were detected in 3 patients based on the CAG findings, with a detection rate of 5.7%, significantly than that by DSCT (30.2%, 21 images of MB in 16 patients, chi2 = 10. 837, P = 0.001). 4D cine mode showed various degrees of "milking effect" and abnormal blood flow in 16 patients with MB. The stenosis rate of tunneled artery during systole was related to the "milking effect" rate on 4D cine mode of DSCTCA (r = 0.640, P = 0.006).
Conclusion: More vividly and reliably showing the "milking effect" than CAG, DSCT can be used as a routine screening method to detect or exclude MB.