title: Prospectively electrocardiogram-gated high-pitch spiral acquisition mode dual-source CT coronary angiography in patients with high heart rates: comparison with retrospective electrocardiogram-gated spiral acquisition mode.
abstract: OBJECTIVE
  To assess the image quality and effective radiation dose of prospectively electrocardiogram (ECG)-gated high-pitch spiral acquisition mode (flash mode) of dual-source CT (DSCT) coronary angiography (CTCA) in patients with high heart rates (HRs) as compared with retrospectively ECG-gated spiral acquisition mode.
  
  
  METHODS
  Two hundred and sixty-eight consecutive patients (132 female, mean age: 55 ± 11 years) with mean HR > 65 beats per minute (bpm) were prospectively included in this study. The patients were divided into two groups. Collection was performed in group A CTCA using flash mode setting at 20-30% of the R-R interval, and retrospectively ECG-gated spiral acquisition mode in group B. The image noise, contrast-to-noise ratio (CNR), image quality scores, effective radiation dose and influencing factors on image quality between the two groups were assessed.
  
  
  RESULTS
  There were no significant differences in image quality scores and proportions of non-diagnostic coronary artery segments between two groups (image quality scores: 1.064 ± 0.306 [group A] vs. 1.084 ± 0.327 [group B], p = 0.063; proportion of non-diagnostic coronary artery segments: segment-based analysis 1.52% (group A) vs. 1.74% (group B), p = 0.345; patient-based analysis 7.5% (group A) vs. 6.7% (group B), p = 0.812). The estimated radiation dose was 1.0 ± 0.16 mSv in group A and 7.1 ± 1.05 mSv in group B (p = 0.001).
  
  
  CONCLUSIONS
  In conclusion, in patients with HRs > 65 bpm without cardiac arrhythmia, the prospectively high-pitch spiral-acquisition mode with image-acquired timing set at 20-30% of the R-R interval provides a similar image quality and low rate of non-diagnostic coronary segments to the retrospectively ECG-gated low-pitch spiral acquisition mode, with significant reduction of radiation exposure.
authors.affiliation: Department of Radiology, Baotou Central Hospital, Inner Mongolia, Baotou 014040, China. henrysk@163.com
authors.forename: Kai
authors.initials: K
authors.lastname: Sun
authors.forename: Rui-Juan
authors.initials: RJ
authors.lastname: Han
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Ma
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Wang
authors.forename: Li-Gang
authors.initials: LG
authors.lastname: Li
authors.forename: Jiu-Hong
authors.initials: JH
authors.lastname: Chen
mesh_terms: D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D016477:Artifacts; D055424:Cardiac-Gated Imaging Techniques; D017023:Coronary Angiography; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D036542:Tomography, Spiral Computed
keywords: Coronary angiography; High heart rates; High-pitch dual-source CT; Prospectively ECG-gated