Dual-source chest CT angiography with high temporal resolution and high pitch modes: evaluation of image quality in 140 patients

Abstract

To evaluate image quality of dual-source computed tomography (CT) angiograms acquired with high temporal resolution and high pitch modes. Two groups of 70 consecutive patients underwent chest CT angiography with dual-source, single-energy CT, with an 83-ms temporal resolution and a pitch of 2 (group 1) or a pitch of 3 (group 2). Subjective and objective image quality and the diagnostic value were assessed by two radiologists in consensus. The radiation dose was recorded. The image quality was always diagnostic in both groups, rated as excellent in 97% of group 1 (68/70) and 98.5% of group 2 (69/70) examinations. Although no statistically significant difference in subjective image noise was found between the two groups (p = 0.3055), objective noise was found to be statistically higher in group 2 (p < 0.0001). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were found to be significantly higher in group 1 than in group 2 (p = 0.0014). The acquisition time was significantly shorter in group 2 than in group 1 (p < 0.0001). The dose-length product was significantly lower in group 2 than in group 1 (p < 0.0001). High temporal resolution and high pitch modes provided standard CT angiographic examinations of excellent quality for thoracic applications in routine clinical practice.