Purpose: To perform a systematic review of the radiation dose and diagnostic accuracy of prospective versus retrospective ECG-gated multislice CT coronary angiography.
Materials and Methods:A search of Pubmed/Medline and Sciencedirect databases for English literature was performed to identify studies comparing prospective and retrospective ECG-gated multislice CT angiography in the diagnosis of coronary artery disease. Effective dose, dose length product, image quality and diagnostic value were compared between two groups of studies.Results: 22 studies were included for analysis. The mean effective dose of prospective ECG-gated scans was 4.5 mSv (95% CI: 3.6, 5.3 mSv), which is significantly lower than that of retrospective scans, which is 13.8 mSv (95% CI: 11.5, 16.0 mSv) (p<0.001). The mean dose length product was 225 mGy.cm (95% CI: 188, 262 mGy.cm) and 822 mGy.cm (95% CI: 630, 1013 mGy.cm) for the prospective and retrospective ECG-gated scans, respectively, indicating a statistically significant difference between these two protocols (p<0.0001). The mean sensitivity and specificity of multislice CT angiography in the diagnosis of coronary artery disease was 97.7% (95% CI: 93.7%, 100%) and 92.1% (95% CI: 87.2%, 97%) for prospective ECG-gated scans; 95.2% (95% CI: 91%, 99.5%) and 94.4% (95% CI: 88.5%, 100%) for retrospective ECG-gated scans, respectively, with no significant difference for sensitivity but significant difference for specificity (p=0.047).
Conclusion:Multislice CT coronary angiography with prospective ECG-gating leads to a significant reduction of radiation dose when compared to that of retrospective ECG-gating, while offering comparable image quality and diagnostic value.3