不同心率下双源CT冠状动脉成像最佳相位窗的研究

Investigation on the optimal phase windows of dual source CT coronary angiography in CHD patients with different heart rates

目的探讨双源CT冠状动脉成像在不同心率下最佳相位窗的选择。方法对100例临床怀疑冠心病或冠状动脉病变患者进行双源CT冠状动脉回顾性心电门控成像扫描,扫描后数据分别按R-R间期10%、20%、30%、40%、50%、60%、70%、80%、90%的相位进行后处理重组,图像行MPR、MIP、容积再现技术(VRT)重组,利用Inspace软件及Circulation软件分析,将图像质量分为4级,按冠状动脉分段标准评价各个节段的图像质量。扫描时记录心率,100例患者心率小于等于60次/min为1组,心率大于60次/min而小于等于80次/min为2组,心率大于80/min而小于等于100次/min为3组,心率大于100次/min为4组。分析观察不同心率组的各时相冠状动脉评分趋势。结果 1、2组70%相位图像质量最好,3、4组40%相位图像质量较好。冠状动脉的图像质量评分与心率有一定的相关性。结论心率越慢图像质量越好,心率越快图像质量越差。最佳时相的选择可以提高诊断冠心病的准确率。

Objective To select the optimal phase windows of dual source CT coronary angiography in coronary heart disease（CHD） patients with different heart rates（HR） . Methods Retrospectively ECG gated dual source CT coronay angiography was performed in 100 patients with clinically suspected or known coronary heart disease. The source images of all patients were postprocessed by using multipla-nar reconstruction（MPR） ,maximum intensity projection（MIP） ,and volume rendering technique（VRT） and then analyzed by using Inspace and Circulation software. The imaging quality of coronary artery segments was classified into four grades according to AHA standard and comparatively evaluated. The heart rate（HR） in scanning was recorded for each case. Coronary CTA data of 100 patients were divided into four groups： group 1,HR≤60 beats per minute（bpm） ,group 2,60 bpm ≤HR≤80 bpm,group 3,80 bpm≤HR≤100 bpm,and group 4,HR100 bpm. Results The imaging quality of group 1 and group 2 was the best in 70% phase window,while that of group 3 and group 4 was better in 40% phase window. The imaging quality of coronary artey imaging was closely correlated with different heart rates and there were significant difference between group 1,2 and group 3,4. Conclusion The study showed that the more low HR the more better imaging quality,contrarily,the more high HR,the more poor imaging quality. Correctly selecting the optimal phase window can elevate the diagnostic accuracy of CHD.