Scoliosis examinations: organ dose and image quality with rare-earth screen-film systems

We determined the dose to the breast and evaluated the image quality when various high-speed, rare-earth screen-film systems were used in conjunction with breast dose reduction methods in children undergoing scoliosis examinations. In addition, normalized organ dose to the breast, active bone marrow, thyroid, eyes, ovaries, and testes were measured in a pediatric anthropomorphic phantom comparing the anteroposterior and posteroanterior projections. The average measured dose to the breast was 6.9 and 4.0 mrad (10(-5) Gy), respectively, for nominal 400- and 600-speed, rare-earth screen-film systems used in combination with breast dose reduction methods. The image quality of these systems as evaluated by three radiologists was rated as adequate. The dosimetry results with an anthropomorphic phantom showed that the posteroanterior projection provides approximately a threefold reduction in breast dose as compared with the anteroposterior view. However, the dose to the bone marrow is doubled. Rare-earth screen-film systems used in combination with simple dose-reduction methods can provide adequate image quality for scoliosis examination while significantly reducing the radiation dose to the breast.