目的探讨浅表型与深在型心 肌桥-壁冠状动脉(MB-MCA)形态学特征 和对载MB-MCA冠状动脉粥样硬化病变有 无差异。方法 回顾性分析122例经128层 螺旋CT冠状动脉血管成像诊断MB-MCA患 者资料，由2名心血管CT诊断医师独立 判断MB-MCA的存在，结果一致时诊断为 MB-MCA。测量MB厚度、MCA长度及MCA狭 窄近端、最窄处、远端管径，计算MCA管 腔狭窄程度，记录MB-MCA位置、包绕情 况、MCA两端成角情况，并记录MCA本身 以及其近、远段冠状动脉粥样硬化病变 情况。应用t检验和卡方检验分析两型间 形态学特征和粥样硬化病变发生率有无 统计学差异。结果 122例CT冠状动脉成 像发现138处MB-MCA，浅表型、深在型各 占69.57%(96/138)和30.43%(42/138)， MCA平均长度分别为22.77±13.97mm和 23.07±12.40mm，MCA管径平均狭窄程度 分别为19.94±13.64%和26.62±16.47%， MCA两端单独或同时成角分别占86.46%和 78.57%。两型间MCA管腔狭窄程度比较有 统计学差异(P=0.01,43＜0.05)。桥近段 冠脉较MCA本身和远段冠脉更易于发生粥 样硬化，有明显统计学差异(P＜0.05)， 两型间各节段粥样硬化发生率分别比较无 统计学差异(P＞0.05)。结论 MB-MCA形态 学特征与其分型无关，但MCA管腔狭窄与 其类型有关，即MCA管腔狭窄程度与MB厚 度有关。载MB-MCA冠状动脉近段容易发生 粥样硬化，MCA及远段冠脉次之，这一特 点亦与其分型无关。

Objective To evaluate the differences of between superficial myocardial bridge-mural coronary artery (MB-MCA) and deep MB-MCA with the morphological characteristics of MB-MCA and the incidence of coronary atherosclerosis. Methods The images of 122 patients who were diagnosed as MB-MCA by128-MSCT were analyzed.The length of MCA and thickness of MB and the stenosis rate of MCA were measured and calculated, and situation of MB, encasement form of MCA, adjacent vessel morphology and the distribution of atherosclerosis were observed. x2 test and t test were used to analyze measurement data between the superior MB-MCA and deep MBMCA. Results 138 sites of MB-MCA were detected in 122 cases. superficial, deep MBMCA in each accounted for 69.57% (96/138) and 69.57% (42/138), average length of MCA were 22.77±13.97mm and 23.07±12.40mm, MCA average stenosis degree were 19.94±13.64% and 26.62±16.47% respectively, alone or at the same time on both ends of the MCA tortuousity accounted for 86.46% and 86.46% respectively. MCA stenosis degree between the two type was statistically significant (P=0.0143). The overall prevalence of coronary atherosclerosis of the proximate segment of MB-MCA was 44.2%, which demonstrated significant difference with atherosclerosis of MCA itself and the distal segment, The incidence of atherosclerosis in each segment between two type was no statistical difference (P>0.05). Conclusion MCA stenosis degree is associated with the type of MB-MCA.MB-MCA predisposes to the development of atherosclerosis in its proximate coronary artery, which is unrelated to the type of MB-MCA.