UNSHARP MASKING OF LOW-DOSED DIGITAL LUMINESCENCE RADIOGRAPHS - RESULTS OF A RECEIVER OPERATING CHARACTERISTICS ANALYSIS

The extent to which the diagnostic performance of low-dosed storage ph osphors can be improved by suitable image postprocessing was investiga ted. Storage phosphor radiographs and conventional 200- and 400-speed screen-film combinations of an anthropomorphic chest phantom with simu lated nodules and linear structures were compared. The detection of te st bodies was determined in an ROC analysis based on 16200 individual observations. The two analog screen-film systems did not differ signif icantly. As far as the storage phosphor radiographs are concerned, a h igher diagnostic performance was achieved with a large filter kernel ( S 40), whereas small filter kernels and edge-enhanced imaging modes re duced the detection of detail. The image quality of low-dosed storage phosphors is thus similar to high-amplification screen-film combinatio ns if large filter kernels are used in postprocessing of the image.