Analysis and results from a UK national dose audit of paediatric CT examinations

Objective: To present the results following a UK national patient dose audit of paediatric CT examinations, to propose updated UK national diagnostic reference levels (DRLs) and to analyse current practice to see if any recommendations can be made to assist with optimisation.Methods: A UK national dose audit was undertaken in 2019 focussing on paediatric CT examinations of the head, chest, abdomen/pelvis and cervical spine using the methods proposed by the International Commission on Radiological Protection. The audit pro-forma contained mandatory fields, of which the post-examination dosimetry (volume CT dose index and dose-length product) and the patient weight (for body examinations) were the most important.Results: Analysis of the data submitted indicates that it is appropriate to propose national DRLs for CT head examinations in the 0-<1, 1-<5, 5-<10 and 10-<15 year age ranges. This extends the number of age categories of national DRLs from those at present and revises the existing values downwards. For CT chest examinations, it is appropriate to propose national DRLs for the first time in the UK for the 5-<15, 15-<30, 30-<50 and 50-<80 kg weight ranges. There were insufficient data received to propose national DRLs for abdomen/pelvis or cervical spine examinations. Recommendations towards optimisation focus on the use of tube current (mA) modulation, iterative reconstruction and the selection of examination tube voltage (kVp).Conclusion: Updated UK national DRLs are proposed for paediatric CT examinations of the head and chest.Advances in knowledge: A national patient dose audit of paediatric CT examinations has led to the proposal of updated national DRLs.