Abstract：Objective: To evaluate the value of low-dose adaptive cardio sequence scan of dual-source CT angiography(DSCTA). Methods: Fifty-one patients with heart rate(HR)≥65 bpm underwent DSCTA with adaptive cardio sequence. They were divided into two groups according to the average HR of patients: For group A with 65 bpm≤HR<75 bpm, 70% of R-R interval was used. For group B with HR≥75 bpm, 40% of R-R interval was chosen. Patients with a body mass index(BMI)≥25 kg/m2 were examined with a tube voltage of 120 kV, whereas BMI＜25 kg/m2 were examined with 100 kV. Both image quality and radiation dose of the two groups were analyzed. Results: A total of 299 coronary artery segments were evaluated in group A and 345 segments in group B. The third and forth grade of the coronary segments for two groups were 91.3% and 92.2%; Right coronary artery(RCA) had the largest percentage of coronary segments in the first and second grade for two groups, and the next was left circumflex artery(LCX); The range of heart rate was 3~44 bpm. The mean score of image quality of group A and group B was (3.53±0.73) and (3.59±0.63) scores, while the total mean effective dose was (2.85±0.93) mSv and (3.10±0.86) mSv. Conclusion: Low-dose adaptive cardio sequence scan for DSCTA can substantially reduce radiation exposure, and obtain good diagnostic image quality in patients with HR≥65 bpm.
2012, Vol. 23 
