title: Prospective versus retrospective ECG-gated multislice CT coronary angiography: a systematic review of radiation dose and diagnostic accuracy.
abstract: OBJECTIVE
  To perform a systematic review of the radiation dose and diagnostic accuracy of prospective versus retrospective ECG-gated multislice CT coronary angiography.
  
  
  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 mGycm (95% CI: 188, 262 mGycm) and 822 mGycm (95% CI: 630, 1013 mGycm) 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Discipline of Medical Imaging, Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U1987 Perth, Western Australia 6845, Australia. z.sun@curtin.edu.au
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Sun
authors.forename: Kwan-Hoong
authors.initials: KH
authors.lastname: Ng
mesh_terms: D001822:Body Burden; D055424:Cardiac-Gated Imaging Techniques; D017023:Coronary Angiography / Q000706:statistics & numerical data*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*