心率对64层螺旋CT冠状动脉造影图像质量的影响及重建相位窗选择的探讨

目的探讨心率对64层螺旋cT冠状动脉造影图像质量的影响及重建相位窗的优选。方法根据心率快慢将86例临床疑患冠心病者分成四组：A组，≤60次／min（beat per minute，BMP），B组61～70BMP；C组，71～BOBMP，D组，〉BOBMP。将冠状动脉图像质量按1～5分共分五个等级，评价不同心率及不同重建相位窗对图像质量的影响。结果患者平均心率为64．4±10．1BMP。共有80．5％（277／344）冠状动脉图像质量可满足诊断要求（〉3分）。不同心率组间冠状动脉图像质量有显著差异，心率越慢图像质量越好（P〈0．05）。重建相位窗的选择以舒张期显著好于收缩期（P〈0．05）。相对时相百分比法（％）和固定时间毫秒法（ms）重建方式对图像质量无显著影响。结论心率是影响图像质量的重要因素之一，降低心率有助于提高图像质量。

Influence of heart rate on image quality of 64-slice spiral computed coronary angiography and optimization on reconstruction of phase window

Objective To evaluate the influence of heart rate on the image quality of 64-slice spiral computed coronary angiography （MSCTCA）and optimize the image reconstruction window. Methods According to the heart rate, 86 patients were classified into 5 groups： group A, the heart rate ≤60 beat per minute（BMP）; group B,61-70BMP, group C,71-80BMP, and group D〉80BMP. The image quality of MSCTCA was scored 5 grades from 1 -5 according to heart motion artifact. The influences of heart rate and reconstruction phase on the image quality of MSCTCA were evaluated. Results Average heart rate was 64.4±10.1BMP. Diagnostic image quality （score〉3） was attained in 277 of 344 segments at the best reconstruction interval. There was a significant correlation between average heart rate and image quality, but there was no difference between relative delay （%） reconstruction and absolute delay （ms） reconstruction on the image quality. Conclusion Reducing average heart rate is beneficial for improving the image quality.