64层螺旋CT心脏冠状动脉检查质量控制和扫描参数优化研究

目的 分析影响64层螺旋CT冠状动脉成像质量的各种因素，对扫描方法进行质量控制和优化。方法 对78例怀疑冠心病或冠心病复查患者进行64层螺旋CT冠状动脉检查，回顾性分析成像质量，探讨心率替代（override）功能的应用价值，分组分析扇区选择与心率对图像质量的影响以及心率与对比剂增强效果的相关性，优化扫描参数。结果 （1）心率替代功能的合理使用可以提高CT冠状动脉的成像质量；（2）心率70次／min以下的单扇区重组图像质量可以满足要求；70-79次／min之间的心率，选择双扇区重组图像的评分要高于单扇区；（3）预测对比剂总量70m1组的平均心率为60．7次／min，65．7％（23／35）的患者增强药量稍显不足；总量为60ml组的平均心率为71．1次／min，52．9％（18／34）的患者增强效果良好。结论 根据心率选择心率替代功能的使用，适当的扇区扫描模式和对比剂总量可以提高图像质量和冠状动脉检查的可靠性。

Quality control and parameter optimization of coronary angiography with 64 multi-slice CT

Objective To control the image quality and to optimize the scan protocols of 64 multi-slice CT coronary imaging by analyzing factors that influence the image quality.Methods Seventy-eight patients with known or suspected CAD underwent CT coronary angiography using 64 multi-slice CT.The image quality in those cases was analyzed retrospectively to derive the optimized scan protocols.The application value of the override function was discussed.The dependency of cardiac reconstruction algorithms and corresponding image quality on patient heart rates was analyzed.In addition,the relationship between heart rate and the contrast-enhancement effect was studied.Results(1)Correct use of override function could improve the quality of cardiac images.(2)For patients with heart rates below 70 beats per minute,the image quality of single-segment reconstruction was satisfactory.For patients with heart rates between 70 and 79 beats per minute,the scores of images reconstructed with two-segments were better than that of single-segment reconstruction.(3)In the group with averaged heart rate of 60.7 beats per minute,the forecast contrast quantity of 70 ml was judged insufficient in 65.7%(23/35)cases;while for the group with averaged heart of 71.1 beats per minute,52.9%(18/34)cases were enhanced well.Conclusion The use of override function,correct segment mode and appropriate contrast quantity could be selected according to the heart rate,which could improve the image quality and reliability.