Systematic review of Paediatric CT and the impact to radiation dose of multigenerational Iterative reconstruction: A longitudinal study.

Abstract

Purpose: A longitudinal study spanning 10 years to investigate impact of radiation dose to Paediatric CT patients when Filtered Back Projection (FBP) and multigenerational Iterative Reconstruction (IR) techniques were utilised. Methods and Materials: Retrospective analysis of 243 paediatric patients for routine CT Chest imaging (age ranging from 23 days to 16 years, median of 5 years) and 216 paediatric patients for routine CT Abdomen imaging (age ranging from 47 days to 16 years, median of 9 years) spanning 2007-2017 were included in this study. Groupings used were 0-1 Years; 2-5 Years; 6-11 Years and 12-16 Years. Period of 2007-2011, CT systems used FBP. Between 2011-2013, Statistical IR (SIR) was routinely utilised. Post 2013, involved routine use of Model-Based IR (MBIR). Average CT Dose Index (CTDIvol) was recorded to best demonstrate differences in actual radiation dose administration. Result(s): Of the 243 CT Chest paediatric patients, 61 (25%) were scanned using FBP, 69 (28%) were scanned using SIR and 113 (47%) were scanned using MBIR. Of the 213 CT Abdomen paediatric patients, 50 (23%) scanned with FBP, 52 (24%) scanned with SIR and 114 (53%) scanned with MBIR. Post SIR introduction, dose administration reduced by an average of 65.32% and an average of 54.73% respectively for paediatric CT Chest and CT abdomen studies across. Post MBIR, dose further reduced by an average of 11.42% and an average of 4.81% for the same studies respectively. Total dose reduction for the same studies was an average of 69.30% and an average of 56.91% respectively. Conclusion(s): In this longitudinal study the use of multigenerational IR techniques for routine Paediatric CT Chest and CT Abdomen studies have significantly impacted administered radiation, achieving an average of 69.30% and 56.91% in overall reduction respectively. Paediatric radio-sensitivity is higher compared to adults thereby requiring the minimum prescribed diagnostic dose achievable. Use of IR should be considered for standard paediatric CT imaging of the chest and abdomen.