Improved image quality at 256-slice coronary CT angiography in patients with a high heart rate and coronary artery disease: comparison with 64-slice CT imaging

Acta Radiol. 2015 Nov;56(11):1308-14. doi: 10.1177/0284185114555152. Epub 2014 Oct 27.


Background: The 256-slice computed tomography (CT) scanners with wider detector coverage and faster gantry rotation speed are now available. The performance of scanners that feature a rotation speed of 270 ms at coronary CT angiography (CCTA) has not been evaluated in patients with a higher heart rate.

Purpose: To evaluate the image quality of 256-slice CT with faster gantry rotation speed in patients undergoing CCTA.

Material and methods: We enrolled 886 patients; 357(40.3%) underwent study on a 64-slice CT at a rotation speed of 420 ms, the other 529 (59.7%) were examined using a 256-slice CT scanner at 270 ms. Two observers judged the image quality of 2658 imaged coronary arteries on a 4-point scale.

Results: The mean image quality score was significantly higher for the 256 - than the 64-slice CT scans (3.94 ± 0.28 vs. 3.73 ± 0.61; P < 0.01). There was no significant difference in the image quality scores between 64 - and 256-slice scans in patients whose heart rate (HR) was <60 bpm. However, in patients whose HR exceeded 60 bpm these scores were significantly higher for 256-slice CT images (P < 0.01).

Conclusion: CCTA performed on the 256-slice CT scanner yielded significantly better image quality in patients with an HR exceeding 60 bpm.

Keywords: 256-slice CT; Coronary CT angiography; computed tomography (CT); heart rate; image quality; rotation speed.

MeSH terms

  • Adrenergic beta-Antagonists / pharmacology
  • Adult
  • Aged
  • Aged, 80 and over
  • Coronary Angiography / methods*
  • Coronary Artery Disease / diagnostic imaging*
  • Coronary Artery Disease / physiopathology*
  • Female
  • Heart Rate / drug effects
  • Heart Rate / physiology*
  • Humans
  • Male
  • Middle Aged
  • Radiation Dosage
  • Radiographic Image Interpretation, Computer-Assisted
  • Retrospective Studies
  • Tomography, X-Ray Computed / methods*


  • Adrenergic beta-Antagonists