64层螺旋CT冠状动脉成像优化方案

目的 研究64层CT冠状动脉CTA成像时合理的对比剂注射时间及自动跟踪结合手动触发扫描技术在CTA中的应用价值.方法 （1）对临床拟诊冠心病的338例患者进行CTA检查,其中自动跟踪智能触发组256例,根据触发时间不同分为三组：＜15 s组、15～19 s组及＞19 s组,探讨触发时间与对比剂注射时间的相关性.自动跟踪手动触发组82例与自动跟踪智能触发15～19 s组106例（最佳组）对照,评价智能触发组与手动触发组对冠状动脉成像质量的影响.（2）对比剂采用优维显（370 mg I/ml）,按1 ml/kg体重给药,剂量多在55～85 ml,适当调节剂量与速率保证对比剂持续注射时间为17 s,注射速率按剂量/17计算.（3）自动跟踪智能扫描组阈值设为120 HU;自动跟踪结合手动触发组阈值设为500 HU.结果 （1）256例受检者叶84%降主动脉起始部对比剂达到阈值的时间在13～18 s,平均为15.8 s,加上3.3 s的屏气时间,再减去2 s的盐水排空时间,对比剂的注射时间为17 s最合理,智能触发组中触发时间为15～19 s的图像质量明显优于其他两组,组间差异有统计学意义（P值分别为0.037和0.040）.（2）手动触发能克服智能触发启动过早或过晚的问题,图像质量明显优于智能触发组,两组问差异有统计学意义（P=0.036）.结论 （1）CTA检查时最佳的对比剂持续注射时间为17 s.（2）自动跟踪结合手动触发的图像质量明显优于自动触发者,应普及推广使用.

Research in optimizing program in 64-MDCT coronary artery angiography

Objective （1）To study the reasonable 64-MDCT coronary artery angiography injection time.（2）To study the application value of 64-MDCT coronary artery angiography automatic tracking combined with manual triggering.Methods （1）256 cases of all 338 patients suspected coronary heart disease undertook automatic tracking intelligence triggering,and were divided into 3 groups according to different triggering time（15 s,15-19 s,19 s）,to study the correlation between triggering time and constrast injection time.Eighty-two cases undertook automatic tracking manual triggering,compared with 106 cases of automatic tracking intelligence triggering group（15-19 s）,and were evaluated the angiography quality of these 2 groups.（2）Ultravist（370 mg I/ml）was used by 1 ml/kg,and the dose was 55-85 ml.Adjust constrast dose and rate to gurantee the constrast continuous injection time is 17 s,and the injection rate was equal to dose number/17.（3）Intelligence triggering group threshold value was set for 120 HU,and manual triggering group threshold value was set for 500 HU.Results （1）Constrast reaching threshold value time was 13-18 s （average,15.8 s） at the beginning part of 84% descending aorta among 256 cases,and plus 3.3 s of holding breath time and minus 2 s saline injection,so the most reasonable constrast continuous injection time was 17 s.Automatic tracking intelligence triggering group（15-19 s） had the best angiography quality compared with 15 s and 19 s groups （P=0.037,0.040）.（2）Auto tracking combined with manual triggering group can avoid scanning too early or too late,and had better angiography quality,compared with intelligence triggering group（P=0.036）.Conclusions （1）The most reasonable 64-MDCT coronary artery angiography injection time was 17 s.（2）Manual triggering had better angiography quality,compared with intelligence triggering.