640层螺旋CT冠脉成像对心肌桥-壁冠状动脉的形态学量化评价及粥样硬化相关性分析

Quantitative evaluation of morphological characteristics and their correlation with atherosclerosis of the myocardial bridge-mural coronary artery by 640 multi-detector spiral CT

目的 利用640层螺旋CT冠状动脉成像对心肌桥-壁冠状动脉（MB-MCA）的形态学特征行定量分析，并探讨其与粥样硬化的关系。方法 收集行冠状动脉成像的186例疑似冠心病患者的影像资料进行分析，若MB-MCA的诊断成立，描述MB-MCA的分布和分型，并在心脏收缩期和舒张期分别记录位于左前降支2段（LAD2）的MB-MCA的厚度以及血管直径，计算其在收缩期及舒张期的变化情况；同时分析MB-MCA粥样斑块情况。结果 186例患者中56例（70段）存在MB-MCA，其中48段（68.6%）位于LAD2；70段MB-MCA中浅表型有44段（62.9%），深厚型有26段（37.1%）。位于LAD2的MB-MCA厚度和直径在心脏收缩期和舒张期差异均有明显变化，差异具有统计学意义（t=2.84、3.38，P均〈0.05）；43段位于LAD2的纳入分析的MB-MCA中有28段（65.1%）为II级狭窄。70段MB-MCA中共48段（68.6%）存在粥样斑块，其中近侧者42段（87.5%），明显高于远侧者6段（12.5%），两者之间的差异有统计学意义（t=3.12，P〈0.05）。结论 640层螺旋CT不仅能直接显示MB-MCA的存在，同时能对其形态特点、伴随心动周期动态变化情况行量化分析，具有较高的临床价值。

Objective To evaluate the morphological characteristics of myocardial bridge and mural coronary artery（MB-MCA） and to discuss the correlation between atherosclerosis and MB-MCA. Methods The coronary artery imaging data of 186 with suspected coronary heart disease patients undergoing 640-slice computed tomography angiograms（CTA） were included. After the MB-MCA diagnosis was confirmed, the location and distribution of MB-MCA were recorded. The diameter and thickness of MB in the middle segment of LAD（LAD2） during the diastole and systole phases were also recorded, and changes in the MB-MCAs were calculated. In addition, the correlation between atherosclerosis and MB-MCA was discussed. Results Among the 186 patients, 70 MB-MCAs were found in 56 patients（30.1%）, whereas 48 MB-MCAs（68.6%） were located in LAD2. According to the MB thickness, 70 patients had MB-MCAs. Among which, 44 patients（62.9%） have the superficial type of MB-MCA, whereas 26（37.1%） have the deep type. The change in the average diameter of MCA in LAD2 from the systole phase to the diastole phase was obvious and statistically significant differences（t=2.84, 3.38, both P〈0.05） were observed. Notably, 28（65.1%） of the patients have MCA diameters indicative of Grade Ⅱ stenosis. Among the 70 diagnosed MB-MCA, 48 segments have atherosclerosis. Atherosclerosis occurred in approximately 42（87.5%） of the MB-MCA patients, which was higher than the occurrence of distal segments in 6 MB-MCA patients（t=3.12, P〈0.05）. Conclusion A 640-slice coronary CTA directly displays MB-MCA and can be used for the quantitative analysis of morphological characteristics and changes in the cardiac cycle of MB-MCA patients to provide reliable imaging data for clinical settings.