Radiation dose and image quality in pediatric chest CT: effects of iterative reconstruction in normal weight and overweight children

Pediatr Radiol. 2015 Mar;45(3):337-44. doi: 10.1007/s00247-014-3176-9. Epub 2014 Sep 26.

Abstract

Background: New CT reconstruction techniques may help reduce the burden of ionizing radiation.

Objective: To quantify radiation dose reduction when performing pediatric chest CT using a low-dose protocol and 50% adaptive statistical iterative reconstruction (ASIR) compared with age/gender-matched chest CT using a conventional dose protocol and reconstructed with filtered back projection (control group) and to determine its effect on image quality in normal weight and overweight children.

Materials and methods: We retrospectively reviewed 40 pediatric chest CT (M:F = 21:19; range: 0.1-17 years) in both groups. Radiation dose was compared between the two groups using paired Student's t-test. Image quality including noise, sharpness, artifacts and diagnostic acceptability was subjectively assessed by three pediatric radiologists using a four-point scale (superior, average, suboptimal, unacceptable).

Results: Eight children in the ASIR group and seven in the control group were overweight. All radiation dose parameters were significantly lower in the ASIR group (P < 0.01) with a greater than 57% dose reduction in overweight children. Image noise was higher in the ASIR group in both normal weight and overweight children. Only one scan in the ASIR group (1/40, 2.5%) was rated as diagnostically suboptimal and there was no unacceptable study.

Conclusion: In both normal weight and overweight children, the ASIR technique is associated with a greater than 57% mean dose reduction, without significantly impacting diagnostic image quality in pediatric chest CT examinations. However, CT scans in overweight children may have a greater noise level, even when using the ASIR technique.

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Male
  • Multidetector Computed Tomography / methods*
  • Overweight / diagnostic imaging*
  • Radiation Dosage*
  • Radiographic Image Interpretation, Computer-Assisted / methods*
  • Radiography, Thoracic / methods*
  • Retrospective Studies