Radiation Dose and Image Quality in Pediatric Cardiac Computed Tomography: A Comparison Between Sequential and Third-Generation Dual-Source High-Pitch Spiral Techniques.

Abstract

The aim of this study was to investigate whether there is a reduction in radiation dose and improvement in image quality of pediatric cardiac computed tomographyscans performed using the high-pitch spiral technique on a new third-generation dual-source 2×192-slice scanner (group B) compared with scans performed using the sequential technique on a single-source 256-slice scanner (group A). We performed a retrospective observational study on 40 patients aged ≤18years who underwent prospectively electrocardiogram-triggered cardiac computed tomography. Image quality was assessed by pre-defined objective indices and a four-point subjective score. Apart from a higher mean heart rate in group A (P=0.016), there were otherwise no significant inter-group differences in patient characteristics. The median effective dose was 4.41mSv (interquartile range 2.58-5.90mSv) in group A and 0.52mSv (interquartile range 0.39-0.59mSv) in group B (P<0.001), representing a 88% reduction. Subjective image quality score was significantly better in group B (4=excellent with no artifact, mode 57.1%) than in group A (3=good with mild artifact, mode 57.9%) (P<0.001). Noise index, signal-to-noise ratio and contrast-to-noise ratio between both groups were not statistically significant. New third-generation dual-source high-pitch spiral scan technique can deliver excellent image quality with low radiation dose. Our results suggest that it should be considered as a first-choice technique for performing cardiac computed tomography in the pediatric population.