Radiation Dose and Risk in the Radiological Investigation of Suspected Non-Accidental Injury (NAI)

Skeletal surveys are a series of X-ray images used to identify bone injuries in suspected cases of non-accidental injury (NAI). This study evaluates effective radiation doses and associated risks of radiation exposure from skeletal surveys that were performed on children under 5 years of age at a tertiary paediatric hospital in Australia.

Radiographic exposure records were retrospectively analysed for 362 initial and follow-up skeletal surveys conducted between 2018 and 2023 for suspected physical abuse. Effective doses and organ absorbed doses were calculated using PCXMC software against background equivalent radiation times (BERT) in Australia. Nominal risks of radiation-induced cancer induction and fatality were estimated using Biologic Effects of Ionising Radiation (BEIR) VII risk coefficients.

The mean effective dose was 0.24 mSv for initial examinations and 0.18 mSv for follow-up examinations, equivalent to 52 and 38 days of background radiation exposure, respectively. The averaged nominal risks associated with an initial skeletal survey are 9.3 in 10,000 for cancer induction, and 3.1 in 10,000 for fatal cancer. Variability of radiation effective dose is demonstrated, with an interquartile range of 0.17-0.30 mSv and an overall range of 0.04-0.76 mSv for initial skeletal surveys.

Radiation doses for initial and follow-up skeletal surveys performed for suspected NAI were determined from a large set of examinations. Several radiation risk metrics have been presented to assist healthcare professionals and caregivers in understanding the associated risks of radiation exposure.