64层螺旋CT冠状动脉成像的心率变化及其对图像质量的影响

目的探讨64层螺旋CT冠状动脉成像的心率变化及心率变化对图像质量的影响。方法回顾性分析138例64层螺旋CT冠状动脉成像资料,记录扫描期间的心率变化,根据不同的心率变化分组。A组心率变化0~4次/min,B组心率变化5~9次/min,C组心率变化10~20次/min,D组心率变化>20次/min。比较不同组间的冠状动脉各节段图像质量差异。结果64层螺旋CT冠状动脉成像心率变化在10次/min以内者占89%,RCA1、RCA3、PDA、LMA、LAD、LCX1及LCX2的图像质量A、B、C组间无显著差异(P>0.05),D组与A、B、C组对比图像质量明显下降(P<0.05);RCA2的A、B、C、D组间对比图像质量有显著差异(P<0.05),呈下降趋势。结论64层螺旋CT冠状动脉成像心率变化幅度小,心率变化>20次/min,才引起冠状动脉成像质量明显下降,RCA2段图像质量易受心率波动的影响。

Fluctuation of Heart Rate and Its Influence on Image Quality of 64-slice Spiral CT in Coronary Angiography

Objective To analyze the fluctuation of heart rate during the scanning and its influence on image quality in coronary angiography with 64-detector spiral CT.Methods A retrospective study was undertaken in 138 cases which had 64-detector spiral CT scan in coronary angiography. Fluctuation of heart rate during the scanning was recorded. 138 cases were divided into 4 groups(group A, fluctuation of heart rate was 0~4 times/ min; group B, fluctuation of heart rate was 5~9 times/ min ; group C, fluctuation of heart rate was 10~20 times/ min ; group D, fluctuation of heart rate>20 times/ min ).The image quality of branches or segments of coronary arteries (total 1104) was compared between different groups. Results The fluctuation of heart rate less than 10 times/min was 89% in all cases. There was no significant differences( P>0.05)in image quality between group A,B and C in the display of RCA1,RCA3,PDA,LMA,LAD,LCX1and LCX2.The image quality in group D was significantly lower than those in group A,B and C in the display of RCA1,RCA3,PDA,LMA,LAD,LCX1 and LCX2. The image quality in RCA2 was significant different among different groups (P<0.05).Conclusion The fluctuation of heart rate in coronary angiography with 64-detector spiral CT is minor.The image quality of coronary artery begins to be poor when the fluctuation of heart rate is greater than 20 times/min especially RCA2.