USE OF AN ASYMMETRIC FILM-SCREEN COMBINAT ION FOR IMAGING PULMONARY NODULES

Purpose: To examine the diagnostic advantages of an asymmetric film-sc reen system (a-FSS) compared to a conventional 200-speed FSS with and without anatomical lung filter. Methods: Standard radiographs were obt ained from an anthropomorphic chest phantom with simulated pulmonary n odules. The existence or non-existence of nodules was assessed in 7344 individual observations. The results were evaluated using ROC analysi s. Results: In an overall evaluation the a-FSS with an ROC area of 0.8 73 +/- 0.018 was not significantly superior (p > 0.05) to the lung fil ter but significantly superior (p < 0.05) to the 200-speed FSS. In the mediastinum the a-FSS and the Lung filter were significantly superior (p < 0.05) to the 200-speed FSS. In the lung areas the 200-speed FSS and the a-FSS attained equivalent results (p > 0.05), whereas the lung filter was rated significantly lower (p < 0.05). Conclusions: Asymmet ric FSS improves chest diagnostics, because it yields significantly mo re diagnostic information in the mediastinum using equivalent x-ray ex posure without reducing the image quality in the lung areas in respect of simulated pulmonary nodules.