64排螺旋CT冠状动脉成像最优成像相位窗的研究

The optimal reconstruction phase of coronary artery imaging with 64-slice helical CT in different heart rate

【目的】探讨64排螺旋CT冠状动脉成像在不同心率下最优成像相位窗。【方法】对450例患者行64排螺旋CT冠状动脉成像，扫描后数据分别在R—R间期5％～95％每隔10％的相位进行后处理重建，对后处理图像按5级评分，记录扫描期间心率，将450例患者按心率〈50次／min为Ⅰ组，心率50～59次／min为Ⅱ组，心率60～69次／min为Ⅲ组，心率〉170次／min为Ⅳ组，分析观察不同心率组的各相位冠状动脉评分趋势。【结果】Ⅰ、Ⅱ、Ⅲ组75％相位图像质量最优，Ⅳ组右冠最优的相位窗为35％，左主干、前降支、回旋支最优的相位窗为35％，Pearson相关分析在R—R35％相位，冠状动脉的图像质量评分与心率无显著相关性。【结论】在不同心率下，64排螺旋CT冠状动脉成像各相位的图像质量有差别，高心率下，可用35％相位的图像来用于诊断。

[Objective] To explore the optimal reconstruction phase of coronary artery imaging with 64-slice helical CT in different heart rates. [Methods] A total of 450 patients underwent coronary angiography using 64-slice helical CT. Raw helical CT data were reconstructed at 5% - 95% of the cardiac cycle with increments of 10 %. 450 patients were divided into 4 groups： group Ⅰ with heart rates less than 50 bpm; group Ⅱ with heart rates between 50 - 59 bpm; group Ⅲ with heart rates between 60 - 69 bpm; group Ⅳ with heart rates more than 70 bpm. Image quality for each coronary was scored as 1, 2, 3, 4 or 5. Evaluated the image quality of coronary artery in different reconstruction phases for different groups, [Results] The optimal reconstruction phase could be achieved at 75% image reconstruction window of cardiac cycle for group Ⅰ Ⅱ Ⅲ In group Ⅳ, the optimal reconstruction phase of RCA was at 35 %, and the optimal reconstruction phase of LMA , LAD, LCX were at 35%. Heart rate didn＇t have correlation with image quality of coronary in 35% cardiac cycle. [Conclusions] In different heart rate, the optimal reconstruction phase of coronary artery are different. The reconstructed image of 35 % cardiac cycle can be used for diagnosis.