Comparison of Prospective and Retrospective Electrocardiogram-triggered Coronary CT Angiography Using Dual-source CT

Objective To compare the image quality and radiation exposure of prospective electrocardio- gram ( ECG) -triggered sequential and retrospective spiral acquisition coronary CT angiography by dual-source CT. Methods Seventy patients with suspected or known coronary artery disease were randomly divided into two groups ( n = 35 ) . Group A underwent prospective ECG-triggered sequential scan and group B underwent retrospective ECG-triggered spiral scan. The image quality and radiation exposure of both modes were evalua- ted. Results There was no significant difference in gender,age,or body mass index between the two groups ( P 0. 05) . The rates of diagnostic coronary segments for group A and group B were 99. 62% and 99. 62% , respectively ( χ 2 = 0. 000,P = 1. 000 ) . The average image quality score was 1. 13 ± 0. 36 in group A and 1. 04 ± 0. 24 in group B,with significant difference between the two groups ( Z = - 5. 073,P = 0. 000) . The mean radiation dose of group A was significantly lower than that of group B [( 3. 47 ± 1. 00) mSv vs. ( 14. 28 ±1. 81) mSv,P = 0. 032]. Conclusion The prospective ECG-triggered sequential scan coronary CT angiogra- phy technique significantly reduces radiation dose without impairing the rates of diagnostic coronary segments when compared with the retrospective ECG-triggered spiral data acquisition in patients with a low and stable heart rate ( ≤70 bpm) . 【