Low-dose adaptive sequence scan of dual-source CT coronary angiography in patients with high heart rate: an initial study

Objective To investigate the application of low-dose adaptive sequence scan of dual-source CT coronary angiography in patients with high heart rate and evaluate the image quality.Methods Seventy-two patients who underwent coronary CT angiography with heart rate> 70 bpm were divided into 2 groups.Group A was adaptive sequence scan, and Group B was retrospective ECG-gating helical scan.Examinations were performed on a dual-source CT scanner (Somatom Definition) .All images were transferred to a workstation for further processing and analysis.The image quality was evaluated using same criteria.The image quality of coronary artery segments was compared in two groups using rank sum test, and the radiation dose was compared using t test Results A total of 501 coronary artery segments were evaluated in group A and 400 segments in group B.The mean ranks in image quality of coronary artery segments in group A was 475.42, whereas 420.41 in group B.There was a statistical difference in image quality between the two groups (Z= - 3.509,P=0.000).The effective dose was on average (6.2±0.9) mSv in group A, whereas on average (14.7±1.9) mSv in group B, there was a statistical difference between the two groups(t= - 27.011, P=0.000).Conclusions Adaptive sequence scan in dual-source CT coronary angiography is feasible in patients with high heart rates.This scan mode can substantially reduce radiation dose and maintain the diagnostic image quality. Key words: Coronary vessels;  Tomography, X-ray computed;  Radiation dosage