Unsharp masking of low-dosed digital luminiscence radiographs: results of a receiver operating characteristics analysis

The extent to which the diagnostic performance of low-dosed storage phosphors can be improved by suitable image postprocessing was investigated. Storage phosphors radiographs and conventional 200- and 400-speed screen-film combinations of an antropomorphic chest phantom with simulated nodules and linear structures were compared. The detection of test bodies was determined in an ROC analysis based on 16 200 individual observations. The two analog screen-film systems did not differ significantly. As far as the storage phosphor radiographs are concerned, a higher diagnostic performance was achieved with a large filter kernel (S 40), whereas small filter kernels and edge-enhanced imaging modes reduced the detection of detail. The image quality of low-dosed storage phosphors is thus similar to high-amplification screen-film combinations if large filter kernels are used in postprocessing of the image.