Coronary Computed Tomography Angiography During Arrhythmia: Radiation Dose Reduction With Prospectively ECG-triggered Axial and Retrospectively ECG-gated Helical 128-slice Dual-Source CT

J Cardiovasc Comput Tomogr. May-Jun 2012;6(3):172-183.e2. doi: 10.1016/j.jcct.2012.04.003. Epub 2012 Apr 7.


Background: Arrhythmia during coronary computed tomography angiography (coronary CTA) acquisition increases the risk of nondiagnostic segments and high radiation exposure. An advanced arrhythmia rejection algorithm for prospectively electrocardiogram (ECG)-triggered axial scans using dual-source CT (DSCT) examinations has recently been reported.

Objective: We compared image quality and effective dose at DSCT examinations using prospectively ECG-triggered axial scanning with advanced arrhythmia rejection software (PT-AAR) versus retrospectively ECG-gated helical scanning with tube-current modulation (RG-TCM) during arrhythmia.

Methods: This was a retrospective case-control study of 90 patients (43 PT-AAR, 47 RG-TCM) with arrhythmia (defined as heart rate variability [HRV] > 10 beats/min during data acquisition) referred for physician-supervised coronary CTA between April 2010 and September 2011. A subset of 22 cases matched for body mass index, HR, HRV, and other scan parameters was identified. Subjective image quality (4-point scale) and effective dose (dose length product method) were compared.

Results: PT-AAR was associated with lower effective dose than RG-TCM (4.1 vs 12.6 mSv entire cohort and 4.3 vs 9.1 mSv matched controls; both P < 0.01). Image quality scores were excellent in both groups (3.9 PT-AAR vs 3.6 RG-TCM) and nondiagnostic segment rates were low (0.1% vs 0.6%). Significantly higher image quality scores were found with PT-AAR in the entire cohort (P < 0.05), and in matched controls with high HRV > 28 beats/min (P < 0.05).

Conclusions: In patients with variable heart rates, prospectively ECG-triggered axial DSCT with arrhythmia rejection algorithm is feasible and can decrease radiation exposure by ∼50% versus retrospectively ECG-gated helical DSCT, with preserved image quality.

Publication types

  • Comparative Study

MeSH terms

  • Arrhythmias, Cardiac / complications*
  • Arrhythmias, Cardiac / diagnostic imaging
  • Cardiac-Gated Imaging Techniques / methods*
  • Coronary Angiography / methods*
  • Coronary Artery Disease / complications*
  • Coronary Artery Disease / diagnostic imaging*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Radiation Dosage*
  • Radiation Protection / methods
  • Radiographic Image Enhancement / methods
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tomography, Spiral Computed / methods*