RESUMEN
BACKGROUND: Recent reports have indicated that infants and young children have a higher sensitivity than older children and adults to radiation exposure and the potential for harmful side effects. OBJECTIVE: To determine whether the present landmarks used in film positioning result in unnecessary radiation to non-thoracic structures on chest radiographs in the pediatric and neonatal population. MATERIALS AND METHODS: Chest radiographs of 195 pediatric patients and 149 neonates were analyzed for extent of radiation field to non-thoracic regions. This was accomplished by delineating the most superior and inferior portions of the body included within the boundaries of collimation on each chest radiograph. The distance between the superior and inferior aspects of the lungs was measured and compared to the long axis of the radiation field on the radiograph. Radiographic reports were reviewed to determine whether valuable data were obtained from the imaging of these non-thoracic structures. RESULTS: The ratio of radiation exposure to non-thoracic structures increases as the age of the patient decreases. Overall, 43% of the length of the chest radiograph was of non-thoracic structures, resulting in radiation exposure to these sites. No significant information was gained in a single case by including the neck. In 3% of the neonatal patients, a potentially significant comment was reported on the abdomen included on the chest radiograph. CONCLUSION: Present positioning techniques in neonatal and pediatric chest radiography result in unnecessary radiation exposure to non-thoracic structures. New landmarks for collimation should be sought to eliminate this problem.