Comparison of some baseline variables and radiation exposure between prospective and retrospective electrocardiography-coupled coronary CT angiography protocols: A single-center observational study

Abstract

Aim: To compare the radiation doses received by patients undergoing coronary computed tomography (CT angiography) using prospective and retrospective electrocardiogram (ECG) simultaneous protocols, considering factors such as age, gender, body mass index, heart rate, and Agatston calcium score.
Methods: A total of 80 patients (heart rate: 45–78 bpm) were retrospectively evaluated. Forty-two (42) patients underwent prospective ECG-gated scanning, and thirty-eight (38) underwent retrospective ECG-gated scanning. Patients' age, gender, body mass index (BMI), Agatston calcium score, dose-length product (DLP), and effective dose (mSv) were recorded. The effective radiation dose (mSv) was calculated by multiplying the DLP by a conversion coefficient of 0.014. The scanner utilized radiation dose-reduction technologies, including CARE kV algorithms, X-CARE (Organ-Based Dose Modulation), CARE Dose 4D and Tin Filter.

Results: The mean effective radiation doses were recorded as 1.54 mSv for the prospective cohort and 2.85 mSv for the retrospective cohort. While no statistically significant disparity was observed based on gender, a weak positive correlation was detected between patient age and radiation dose (r=0.09, p<0.05).
Conclusion: Prospective ECG-triggered acquisition yields significantly lower radiation exposure than retrospective protocols, contingent upon rigorous patient selection and the maintenance of appropriate heart rate limits. Irrespective of the scanning technique employed, a positive correlation was established between effective radiation dose and both Body Mass Index (BMI) and heart rate, whereas no statistically significant association was found regarding age or gender. While the relationship between Agatston score and effective dose appeared more distinct within the retrospective cohort, it presented only a weak positive correlation that failed to reach statistical significance.