[Use of a digital radiology system with phosphors in the assessment of thoracic diseases in bedside radiography].

We report our experience with a storage phosphor radiography system; to assess both the image resolution and the dynamic range of the system, a phantom simulating chest average density was used. Finally, we investigated the system impact on portable chest radiographs. The radiographs were taken on 35 x 43 cm phosphor plates, with 80 kV, 3 mAs and focus-film distance of 130 cm. The phosphor plates were scanned with a 75 microns laser beam, postprocessed with the system software and, finally, printed on a 20 x 25 cm film. As reported by other Authors, the storage phosphor system showed similar spatial resolution to conventional radiography (2.5 lp/mm for 35 x 43 cm films and 4.5 lp/mm for 20 x 25 cm films), a wide dynamic range always allowing correcting exposure, but increased noise; these features allow film density optimization even in such "critical" situations and bedside radiographs. Pneumonia, pneumothorax, emphysema, pleural effusions and catheters or tubes positioning were always easily depicted. In our experience, the phosphor plate storage system exhibits many advantages over conventional radiography, namely image postprocessing, the opportunity to choose between several sizes of laser films and finally, the possibility of linking the system to a network and possibly to a digital archive. The main drawbacks of the system are its increased noise and, at present, with the available hardware, slow plate reading.