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

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 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. Key words: Radiation doses; Tomography spiral computed; Coronary vessels; Heart rate