256层CT冠状动脉成像对心肌桥-壁冠状动脉的形态学评价及量化分析

Morphological and quantitative evaluation of myocardial bridge and mural coronary artery with 256-slice CT angiography： initial clinical experience

目的利用256层螺旋CT冠状动脉成像探讨心肌桥-壁冠状动脉（MB-MCA）的形态学特征及多时相重建量化分析MCA在心脏收缩期和舒张期的变化。方法收集自2010年6月至2011年4月来北京中日友好医院放射科进行冠状动脉成像检查的861例患者的影像资料。由两位有经验的放射科医师独立分析患者的影像资料，当两者意见取得一致时，MB．MCA的诊断成立。描述MB．MCA分布，并在心脏收缩期和舒张期分别记录位于LAD的MB-MCA的长度、厚度以及血管直径，由此可以计算其在收缩期及舒张期的变化情况。结果在861例患者中有131（15．2％）例存在150段MB．MCA，其中99（66．0％）段MB-MCA位于LAD中段，剩余51（34．O％）段位于其他节段。MB的平均长度和厚度分别为（17．6±5．7）mm，（2．7±0．7）mm。LAD中段的MCA从心脏收缩期到舒张期的管径变化为（1．2±0．5）mm，而且41％的MCA在心脏收缩期管径狭窄达到50％以上。结论利用256层CT除了可以描述MB-MCA的形态学特点，还可以利用多时相重建技术在一定程度上评价MCA在心脏收缩期和舒张期的变化情况。

Objective To determine the morphological characteristics of myocardial bridge and mural coronary artery （MB-MCA） and initially quantify the changes of MB-MCA in diastole and systole phase with multiple-phase reconstruction technique using 256-slice CT angiography （256-slice CTA）. Methods We retrospectively collected the coronary artery imaging data of 861 patients undergoing 256-slice CTA with suspected or documented coronary artery disease. The images were reviewed by two independent radiologists, the diagnosis of MB-MCA was confirmed when consistency was obtained. The length, diameter and thickness of MB-MCA in the middle segment of LAD （LAD2） in diastole and systole phase were recorded, and changes of MB-MCA were calculated. Results Among the 861 patients, 150 MB-MCA were found in 131 patients （15.2%） .99 MB-MCA （66.0%） were located in LAD2, the remaining 51 （ 34. 0% ） in the other segments of coronary arteries. The average length and thickness of MB was （ 17.6 ± 5. 7） mm and （2. 6 -± 0.7） ram, respectively. The average diameter change of MCA in LAD2 from systole phase to diastole phase was （ 1.2 ±0. 5 ） mm, and 41% of MCA have diameter stenosis more than 50% in systole phase. Conclusion The changes of MB-MCA from diastole to systole phase could be determined to some extent by 256-slice CTA multiole-phase reconstruction teehnique.