Dose evaluation in paediatric patients undergoing chest X-ray examinations

This study aimed to estimate the incident air kerma in chest X-ray examinations, for lateral (LAT) and anterior posterior (AP) (together with posterior anterior (PA)) projections, in one of the largest paediatric hospitals in Brazil, and to compare these with the results obtained in a general hospital of the same city. The dosimetric results were analysed along with the patient characteristics and radiographer strategies. The examinations of 225 (119 male and 106 female) patients were studied and 389 X-ray scans (200 AP/PA projections and 189 LAT projections) of paediatric patients were acquired. For analysis of the results, the patients were divided into the following age groups: 0-1 y, 1-5 y, 5-10 y, and 10-15 y. Patient's thickness can be determined from age, height or weight with an uncertainty of 20-30%. In different hospitals, the difference in patient's thicknesses between the same age groups can reach 25-55%. A minimal correlation between the patient dose and thickness was observed, with a 4 -fold difference in the dose for patients of the same thickness. By standardizing radiological protocols, it should be possible to keep the dose within intervals of 50-100 p mu Gy for LAT projection and 40-80 mu Gy for AP/PA projection.