双源CT前瞻性和回顾性心电门控冠状动脉成像对比研究

目的:通过对双源CT前瞻性与回顾性心电门控冠状动脉成像的图像质量和辐射剂量等比较,探讨双源CT前瞻性触发序列扫描技术在冠状动脉成像中的应用价值.方法:将110例行双源CT冠状动脉血管成像检查的患者随机分为2组,A组60例行前瞻性触发序列门控扫描,B组50例行回顾性心电门控螺旋扫描.入组标准为心率75次/min(bpm)以下,心率相对规整(波动≤10bpm).管电压根据体重质量指数(BMI)调整:BM1≥25kg/m2,120kV;BMI＜25kg/m2,100kV.记录扫描中患者所接受辐射剂量,并对其图像质量进行评分.分别采用Wilcoxon秩检验和两独立样本t检验对两组的图像质量和辐射剂量进行统计学分析.结果:A组图像质量平均评分为(3.74±0.51)分,平均有效剂量为(2.38±0.83) mSv;B组图像质量平均评分为(3.68±0.58)分,平均有效剂量为(9.49±3.38)mSv.A、B两组图像质量评分差异无统计学意义(Z =-1.891,P=0.059)；有效剂量差异有统计学意义(t=-14.522,P＜0.001),降低约75％.结论:双源CT在心率低且稳定的患者中行前瞻性触发序列扫描能够显著降低辐射剂量,并且可以获得满足临床诊断的图像质量.

Comparative study of prospective and retrospective electrocardiogram gated dual-source computed tomography coronary angiography

Objective：To compare the image quality and radiation dose values of prospectine and retrospective electrocardiogram（ECG） Gated dual-source computed tomography coronary angiography（CTCA）.Methods：A total of one hundred and ten patients referred for coronary dual-source CT angiography were randomly divided into 2 groups： group A（60 cases）using prospective ECG-triggering sequence scan mode and group B（50 cases）using retrospective ECG-gating helical scan.Inclusion criteria included heart rate ≤75 bpm,and heart rate variability ≤10 bpm.Patients with a body mass index（BMI） ≥25 kg/m2 were examined with a tube voltage of 120 kV,whereas,BMI﹤25 kg/m2 were examined with 100 kV.The radiation dose was recorded and the image quality was blindly evaluated.The image quality and radiation dose were compared with Wilcoxon rank sum test and t-test between the two groups respectively.Results：The mean score of image quality in group A was（3.74±0.51） and that in group B was（3.68±0.58）.There was no significant difference in image quality between the two groups（Z=-1.891,P=0.059）.Mean estimated radiation dose of group A,B was（2.38±0.83）,（9.49±3.38） mSv,respectively.There was a significant difference between the two groups（t=-14.522,P﹤0.001）,and the radiation dose of group A was reduced by 75%.Conclusion：In patients with low and stable heart rates,the sequential scan technique is a promising method to effectively reduce radiation exposure and to maintain diagnostic image quality on dual-source CT.