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 electrocardiogram (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 evaluated.

  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 (χ²=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 angiography 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).