Coronary Computed Tomography Angiography: Patient-related factors determining image quality using a second-generation 320-slice CT scanner

Int J Cardiol. 2016 Oct 15:221:970-6. doi: 10.1016/j.ijcard.2016.07.141. Epub 2016 Jul 9.

Abstract

Purpose: To investigate the diagnostic confidence of Coronary Computed Tomography Angiography (CCTA) and the effect of patient-related factors on CCTA image quality using a second-generation 320-slice scanner.

Methods and results: 200 consecutive patients (mean age 60±12years; 109 men) prospectively underwent CCTA. The mean body mass index (BMI) was 27.1±4.9kg/m(2); the median heart rate (HR) was 60.0 (interquartile range (IQR), 53.9-66.1) beats per minute (bpm). The median segment's diameter was 2.8 (IQR, 2.2-3.4) mm. For each coronary segment ≥1.5mm in diameter, two readers scored: diameter narrowing as < or ≥50%, overall diagnostic confidence and motion-related image quality, with interobserver agreement kappa-values of 0.89, 0.91 and 0.61 respectively. Seventy-nine of the 2505 evaluated segments (3.2%) had non-diagnostic image quality because of coronary calcifications (66/79; 83.5%), stent- (6/79; 7.5%), pacemaker- (2/79; 2.5%) or motion-related artifacts (5/79; 6.5%). The effect of patient-related factors on motion-related image quality was investigated by multinomial logistic regression in 181 patients with calcium score (IQR, 0-446.5). Increasing coronary diameter was the most improving image quality factor (odds ratio (OR), 1.8637; p<0.001), marginally followed by lower HR (OR, 0.9547; p<0.001) and calcium score (OR, 0.9997; p=0.04). Gender (p=0.70), age (p=0.24) and BMI (p=0.45) did not affect image quality.

Conclusion: Using a second-generation 320-slice scanner, CCTA diagnostic confidence is predominantly affected by coronary calcifications, whereas motion-related image quality is non-diagnostic only in exceptional cases and mainly influenced by the coronary diameter. For future developments, our study findings therefore suggest greater requirements concerning spatial resolution and calcium-related artifact removal than concerning temporal resolution, especially to improve diagnostic confidence in patient groups with smaller coronary diameters.

Keywords: Coronary CT angiography; Coronary calcifications; Coronary diameter; Diagnostic confidence; Image quality; Patient-related factors.

MeSH terms

  • Aged
  • Computed Tomography Angiography* / instrumentation
  • Computed Tomography Angiography* / methods
  • Coronary Angiography* / instrumentation
  • Coronary Angiography* / methods
  • Coronary Artery Disease / diagnosis*
  • Coronary Vessels* / diagnostic imaging
  • Coronary Vessels* / pathology
  • Data Accuracy
  • Dimensional Measurement Accuracy
  • Female
  • Humans
  • Male
  • Middle Aged
  • Organ Size
  • Reproducibility of Results
  • Tomography Scanners, X-Ray Computed / standards
  • Vascular Calcification / pathology