1.5 T磁共振全心冠状动脉成像技术改进

Technical improvement of 3-D whole-heart coronary artery MRI

目的提高全心冠状动脉MR成像(WH-MRCA)的图像质量。方法对17例疑诊冠心病者,采用1.5 T非对比增强、心电门控兼呼吸导航、T2预备脉冲并脂肪抑制的3D稳态自由进动序列扫描,分别用Siemens的序列、方法扫描(对照组)和改进的序列、方法(实验组)进行扫描,对得到的A、B两组数据采用4分制评价图像质量。结果实验组显示51支冠状动脉主干均可良好显示,对照组显示46支,且血管的显示质量一般。用实验组扫描方式完成48例冠状动脉检查,144支冠状动脉主干均可良好显示。结论心脏静止时间开始图像的触发时间(TT)并不等于数据窗口的开始时间,一个心动周期内的全心冠状动脉成像应加上心脏的准备时间,心脏的准备时间跟心率成负相关趋势。

Objective To improve image quality of whole-heart coronary artery(CA)MRI.Methods Seventeen patients with suspected coronary artery disease underwent CA MRI including three-dimensional(3-D)steady-state free precession sequence with ECG gating,respiratory navigation,T2 preparation pulse and fat suppression on a 1.5 T Siemens MR system.Two sets of images were acquired using the standard sequence supplied by the vendor and an improved sequence.The image quality of the 2 sequences was compared using a 4-point system.Results The improved sequence showed 51 main CAs including 48/144 main CAs with good image quality compared to the 46 CAs of average image quality demonstrated on standard sequence.Conclusion The trigger time of imaging the heart at rest is not equal to the starting time of the data window.Whole-heart CA MRI in a cardiac cycle should add the preparation time of the heart.The preparation time of the heart has a negative correlation with the heart rate.