基于小剂量测试法单次屏气行冠状动脉减影技术的优势研究

A Study of Single Breath-Hold Coronary Subtraction Technology Based on Low-Dose Test Method

目的提高冠状动脉CT血管成像减影技术(Sub-CCTA)的减影成功率。方法通过Canon Aquilion Vision前瞻性搜集2018年1月至2018年8月行冠状动脉CT血管成像(CCTA)检查者的资料,共290例患者纳入研究,其中145例患者(男80例,女65例,年龄14~90岁,平均57岁)作为实验组(A组):正式扫描之前先进行小剂量测试法,向患者体内注入少量对比剂,将左冠状动脉窦处设置为感兴趣区(ROI),监测ROI血管的CT值,记录对比剂到达血管的峰值时间;正式扫描时嘱患者一次屏气,对比剂注入后5 s钙化积分模式迅速采集蒙片,到达峰值时间时前瞻性心电门控Prosp CTA模式扫描冠状动脉期相;另145例患者(男82例,女63例,年龄27~90岁,平均59岁)作为对照组(B组):先用钙化积分模式扫描蒙片,随后注射对比剂,通过Sure Expretron智能示踪法Prosp CTA模式扫描冠状动脉期相,前后需患者屏气两次;将A组和B组的患者依据扫描期间的平均心率各自分成5个心率区间(<50次/分、50~65次/分、66~75次/分、76~90次/分、91~120次/分,A、B组各5例、82例、34例、18例、6例);采用冠状动脉17段评估法,在每个心率区间对A、B两组的减影效果进行客观对比分析,采用冠状动脉评估6分法进行减影图像质量主观对比。结果A组与B组减影图像质量主、客观比较分析,平均心率在50~65次/分和66~75次/分的患者,A组平均达到优秀例数多于B组(Mann-Whitney U秩和检验统计结果显示,减影图像质量主观评分P值依次为0.008、0.025,P<0.05为差异有统计学意义,优秀率A组分别为92.68%、47.06%,B组为78.03%、26.47%,A组均高于B组;客观评分P值依次为0.001、0.022,P<0.05为差异有统计学意义,A组均值14.54、10.62均高于B组均值12.82、7.74);平均心率为<50次/分、76~90次/分、91~120次/分的患者,A、B两组减影效果主观评分无统计学差异,客观评分只在76~90次/分有统计学差异[3],A组均值8.17高于B组均值3.39(P<0.05)。结论在相同心率区间内,相比传统CCTA扫描技术,基于小剂量测试法单次屏气行Sub-CCTA可提高CCTA的减影成功率,进而提高冠状动脉狭窄的诊断准确率,为临床诊断冠状动脉血管疾病提供重要临床价值。

Objective To investigate the feasibility of single breath-hold coronary subtraction technology based on low-dose test method.Methods We prospectively collected CT angiography data of patients who underwent CCTA examination from January 2018 to August 2018,acquired using Canon Aquilion Vision.A total of 290 patients were included in the study,including 145 patients(80 males,age range 14-90 years,Average age 57 years old)as the experimental group A.The aortic peak time was obtained by low-dose test bolus at first.Coronary calcium score scanning was performed as a mask 5 seconds after contrast agent injection,and CCTA scanning was completed at the peak time in one breath holding;(2)Reference group B(n=145 patients):Mask phase of coronary calcium score and CCTA phase with tracking method were performed during two separate breath-holding actions.The patients in the experimental group A and the control group B are divided into 5 heart rate intervals according to the average heart rate during the scan(<50 bpm,50-65 bpm,66-75 bpm,76-90 bpm,91-120 bpm,5 persons,82 persons,34 persons,18 persons,and 6 persons in group AB).A 6-point-scale(1-2:poor,3-4:moderate,5-6:excellent)and coronary 17-segment method were used for subjective and objective evaluation of subtraction image quality.Results In the 50-65 bpm and 66-75 bpm range group,the subjective evaluation of subtraction success rate was increased between group A and group B(from 78.03%to 92.68%,P=0.008;26.47%to 47.08%,P=0.025)as well as in objective coronary 17-segment score(mean score from 12.82 to 14.54,P=0.001;7.74 to 10.62,P=0.022);There was no statistical difference between the two groups in the success rate in<50 bpm(P=0.317),76-90 bpm(P=0.076),91-120 bpm(P=0.575)range.Among these 3 ranges,statistical difference in the objective coronary 17-segment score could only be seen in the 76-90 bpm range from 3.39 with group B to 8.17 with group A(P<0.05).Conclusion Our study demonstrates that within certain average heart rate ranges,single breath-hold coronary subtraction technology based on low-dose test method increased success rate of CCTAsub compared with conventional CCTAsub method,which is helpful in the clinical diagnosis of coronary artery diseases.