Radiation dose considerations in common paediatric X-ray examinations

Background: For paediatric radiology, diagnostic reference levels (DRLs) have been proposed by the National Radiological Protection Board and the European Commission, representing a baseline above which re-evaluation of the equipment and the techniques used is necessary. Objective: To measure the entrance surface dose (ESD) in various paediatric radiological examinations carried out at a large paediatric hospital in Greece and compare them with the existing DRLs. Materials and methods: Measurements of ESD using thermoluminescent dosemeters were carried out in a sample of 168 paediatric patients who underwent various common radiological examinations (chest, skull, pelvis, lumbar spine, full spine). The patients were categorised according to age, and the mean ESD was calculated for each examination and age category. Additionally, the effective doses were estimated from measured ESD using appropriate conversion coefficients found in the literature. Results: The mean ESD values were found to be well below the proposed DRLs for all the examinations studied except for the chest, owing to the low tube potential used and tube filtration. Conclusions: Even in examinations that did not exceed the DRL, patient protection can be optimised further by appropriate collimation of field size to that necessary for diagnosis.