目的　研究心肌桥-壁冠状动脉（MB-MCA）的双源CT（DSCT）形态学特征，以提高对MB-MCA临床诊断价值的认识。  方法　分析3709例冠状动脉CTA病人，根据美国心脏病协会的冠状动脉16段分段法对检出的MB-MCA进行准确定位，对其长度、深度、收缩期管腔压缩程度及其伴随的粥样硬化情况进行评估。  结果　3709例病人中发现MB-MCA 638例，检出率约17.20%，共检出654支　MB-MCA，其中426支位于7段（S7）、 72支位于8段（S8）、56支位于6段（S6），其余分别分布于2段（S2）、3段（S3）、4段（S4）、9段（S9）、11段（S11）、 12段（S12）、13段（S13）及16段（S16）；MB-MCA平均长度为（20.52±9.84）mm，平均深度为（1.27±0.93）mm；收缩期时MCA管腔呈现不同程度的狭窄，但重度狭窄罕见；92例MB-MCA患者在MCA前存在粥样硬化斑块。  结论　DSCT不仅可直接显示　MB-MCA的解剖形态，还可动态评价其在整个心动周期的变化，为MB-MCA临床意义的研究提供了有价值的信息。

Objective　To study the morphologic features of myocardial bridge-mural coronary (MB-MCA) by dual-source CT (DSCT), and improve the understanding of it on clinical diagnosis value. Methods　3709 patients were involved in this study. MB-MCAs were located accurately according to the guideline of the American Heart Association, and the length, depth, compression of MB-MCA and concomitant atheromatous changes were evaluated.　Results　638 cases had MB-MCA in overall 3709 patients by DSCT, getting the prevalence of 17.20%. 654 MB-MCA were detected including 426 in segment 7, 72 in segment 8 and 56 in segment 6, the rest distributing in segment 2, 3, 4, 9, 11, 12,13 and 16. Of 654 MB-MCA, the mean length was (20.52±9.84）mm and the mean thickness was（1.27±0.93）mm. The lumen of MCA showed no significant stenosis or mild to moderate stenosis, and a rare severe stenosis. 92 patients with MB-MCA had atherosclerotic plaque.　Conclusions　DSCT not only may directly demonstrate the dissection shape of MB-MCA, but might also dynamically evaluate the change of MB-MCA in the entire cardiac cycle, supplying the clinical significance research of MB-MCA for valuable information.