Dose measurements in chest diagnostic X rays: adult and paediatric patients.

This survey was carried out in the state of São Paulo, Brazil. The health services located in the state perform approximately 321 radiological examinations per 1000 inhabitants. A representative sample of 200 health services was selected using sampling techniques, and a postal dosimetric kit was sent to each one who agreed to participate. The kit evaluates entrance surface dose (ESD), making use of thermoluminescence dosemeters attached to the skin of patients. The radiographic technique employed and some physical data of patients were also gathered. In this stage of the survey, only chest examinations, projections AP, PA and LAT, were evaluated. A total of 917 ESD values were measured, which correspond to 588 patients and 74 examination rooms. The ESD to patients were analysed according to weight and age. Groups of standard patients (children and adults) were selected, and reference doses were determined. Large variations of ESD were observed, indicating that much can be done in order to reduce the patient doses by changing the technical parameters. Moreover, the results of ESD in paediatric radiology point to the necessity of special attention in the practice of radiological examinations in this age group.