Noninvasive coronary angiography with 16-detector row CT: effect of heart rate

Radiology. 2005 Jan;234(1):86-97. doi: 10.1148/radiol.2341031408. Epub 2004 Nov 18.


Purpose: To evaluate the effect of heart rate on the quality of coronary angiograms obtained with 16-detector row computed tomography (CT) by using temporally enhanced three-dimensional (3D) approaches.

Materials and methods: The local ethics committee approved the study, and informed consent was obtained from all patients. Fifty patients underwent coronary CT angiography (heart rate range, 45-103 beats per minute). Raw data from helical CT and electrocardiography (ECG) were saved in a combined data set. Retrospectively ECG-gated images were reconstructed at preselected phases (50% and 80%) of the cardiac cycle. A 3D voxel-based approach with cardiac phase weighting was used for reconstruction. Testing for correlation between heart rate, cardiac phase reconstruction window, and image quality was performed with Kruskal-Wallis analysis. Image quality (freedom from cardiac motion-related artifacts) was referenced against findings at conventional angiography in a secondary evaluation step. Regression analysis was performed to calculate heart rate thresholds for future beta-blocker application.

Results: A significant negative correlation was observed between heart rate and image quality (r = 0.80, P < .001). Motion artifact-free images were available for 44 (88%) patients and were achieved consistently at a heart rate of 80 or fewer beats per minute (n = 39). Best image quality was achieved at 75 or fewer beats per minute. Segmental analysis revealed that 97% of arterial segments (diameter > or = 1.5 mm according to conventional angiography) were assessable at 80 or fewer beats per minute. Premature ventricular contractions and rate-contained arrhythmia did not impede diagnostic assessment of the coronary arteries in 10 (83%) of the 12 patients affected.

Conclusion: Motion-free coronary angiograms can be obtained consistently with 16-detector row CT scanners and adaptive multicyclic reconstruction algorithms in patients with heart rates of less than 80 beats per minute.

MeSH terms

  • Adult
  • Aged
  • Coronary Angiography / methods*
  • Coronary Disease / diagnostic imaging*
  • Electrocardiography
  • Female
  • Heart Rate / physiology*
  • Humans
  • Image Processing, Computer-Assisted
  • Imaging, Three-Dimensional*
  • Male
  • Middle Aged
  • Regression Analysis
  • Statistics, Nonparametric
  • Tomography, X-Ray Computed / methods*