自然心率下128层双源Flash Spiral CT冠状动脉成像质量及辐射剂量的研究

目的 探讨自然心率下舣源CT Flash螺旋心脏模式和前瞻性心电触发序列模式的冠状动脉成像质量及辐射剂量,以实现个性化低剂量冠状动脉扫描模式的选择.方法 将60例行CT冠状动脉血管成像(CTCA)检查的患者分为2组,A组27例行Flash螺旋心脏模式扫描,入组标准:心率65次/min(bpm)以下,窦性心律且律齐,心率波动范围在±5 bpm以内.采集期相为60%R-R间期.B组33例行前瞻性心电触发序列(SAS)扫描,入组标准:(1)心率≥65 bpm,(2)心律不齐、早搏、心房颤动.排除标准:屏气不佳者.采集期相:(1)心率≤75 bpm为60%-80%R-R间期,(2)心率>75 bpm为30%-50%R-R间期,(3)心律不齐、早搏、心房颤动为20%～90%R-R间期.2组的管电压均随体质量指数(BMI)调整,BMI≥25.0 kg/m2管电乐采用120 kV,BMI<25.0 kg/m2管电压采用100 kV,A组的BMI为(24.6±1.0)ks/m2,B组的BMI为(24.6±0.9)kg/m2.对2组扫描的冠状动脉分别做图像后处理,应用两独立样本t检验对2组患者冠状动脉段图像质量评分及辐射剂量进行统计分析.结果 可评价的冠状动脉节段748段,其中A组336段、B组412段;A组冠状动脉段图像质量评价为优良者达98.2%(330/336),B组的达98.1%(404/412),2组图像质量评分差异无统计学意义(t=0.513,P=0.608).A组平均有效剂量为(0.74 4-0.29)mSv,B组为(3.67±1.37)mSv,2组之间差异有统计学意义(t=-10.858,P=0.000).结论 2组个性化低剂量冠状动脉扫描模式可在保证图像质量的同时显著降低辐射剂量.

Abstract：

Objective To compare the quality and radiation doses of coronary artery angiography under the natural heart rate condition between Flash spiral heart mode and prospective electrocardiogramtriggering sequence mode using dual-source,in order to choose personalized low doses of coronary artery scanning mode.Methods Sixty patients who underwent coronary angiography(CTA)on a 128-slice,dualsource CT scanner were divided into 2 group i.e,group A(27cases)and group B(33 cases).Flash spiral heart scan mode was employed for group A.Inclusion criteria included:heart rate<65 bpm.regular sinus rhythm,heart rate fluctuation less than ±5 bpm.Date acquisition was set at 60% of the R-R interval.Prospective electrocardiogram-triggering sequence scan mode(SAS)was performod for group B.Inclusion criteria included:(1)heart rate≥65 bpm,(2)arrhythmias,premature beat,fibrillation atrial.Exclusion criteria included:bad holding breath.Date acquisition(1)At low heart rate(≤75 bpm),date acquisition was set at 60%-80%of the R-R interval.(2)At high heart rate(>75 bpm),date acquisition was set at 30%-50%of the R-R interval. (3)At the arrhythmias,premature beat,fibrillation atrial,date acquisition was set at 20%-90%of the R-R interval.In both gronps,patients with a BMI≥25.0kg/m2 were examined with a tube voltage of 120 kV.while the other patients with a BMI<25.0 kg/m2 were examined with a tube voltage of 100 kV.The BMl was(24.6±1.0)kg/m2 in group A,while that was (24.6±0.9)kg/m2 in group B.In both groups,all images were transferred to the workstation for further processing and analysis.The imaging quality of coronary artery segments and the radiation dose were compared with t test.Results A total of 336 coronary artery segments were evaluated in group A and 412 segments were evaluated in group B.The imaging quality of coronary artery segments were scored.Excellent or good was achieved in 98.2%(330 of 336)artery segments in group A,and that was 98.1%(404 of 412)in group B.There was no statistical difference in imaging quality between the two groups(t=0.513,P=0.608).The average effective dose was(0.74±0.29)mSv in group A,whereas that was(3.67±1.37)mSv in group B.There was a significant difference between the two groups(t=-10.858,P=0.000).Conclusions The personalized low doses coronary artery scanning mode can substantially reduce radiation damage while preserving good imaging quality.

Optimized imaging quality and radiation dose for coronary artery angiography using 128-slice,dual-source Flash Spiral CT under the natural heart rate

Objective To compare the quality and radiation doses of coronary artery angiography under the natural heart rate condition between Flash spiral heart mode and prospective electrocardiogramtriggering sequence mode using dual-source,in order to choose personalized low doses of coronary artery scanning mode.Methods Sixty patients who underwent coronary angiography(CTA)on a 128-slice,dualsource CT scanner were divided into 2 group i.e,group A(27cases)and group B(33 cases).Flash spiral heart scan mode was employed for group A.Inclusion criteria included:heart rate<65 bpm.regular sinus rhythm,heart rate fluctuation less than ±5 bpm.Date acquisition was set at 60% of the R-R interval.Prospective electrocardiogram-triggering sequence scan mode(SAS)was performod for group B.Inclusion criteria included:(1)heart rate≥65 bpm,(2)arrhythmias,premature beat,fibrillation atrial.Exclusion criteria included:bad holding breath.Date acquisition(1)At low heart rate(≤75 bpm),date acquisition was set at 60%-80%of the R-R interval.(2)At high heart rate(>75 bpm),date acquisition was set at 30%-50%of the R-R interval. (3)At the arrhythmias,premature beat,fibrillation atrial,date acquisition was set at 20%-90%of the R-R interval.In both gronps,patients with a BMI≥25.0kg/m2 were examined with a tube voltage of 120 kV.while the other patients with a BMI<25.0 kg/m2 were examined with a tube voltage of 100 kV.The BMl was(24.6±1.0)kg/m2 in group A,while that was (24.6±0.9)kg/m2 in group B.In both groups,all images were transferred to the workstation for further processing and analysis.The imaging quality of coronary artery segments and the radiation dose were compared with t test.Results A total of 336 coronary artery segments were evaluated in group A and 412 segments were evaluated in group B.The imaging quality of coronary artery segments were scored.Excellent or good was achieved in 98.2%(330 of 336)artery segments in group A,and that was 98.1%(404 of 412)in group B.There was no statistical difference in imaging quality between the two groups(t=0.513,P=0.608).The average effective dose was(0.74±0.29)mSv in group A,whereas that was(3.67±1.37)mSv in group B.There was a significant difference between the two groups(t=-10.858,P=0.000).Conclusions The personalized low doses coronary artery scanning mode can substantially reduce radiation damage while preserving good imaging quality.