Imaging performance of a digital storage phosphor system.

The imaging performance of a storage phosphor system (SPS) for digital projection radiography is studied in which the x-ray image is temporarily stored in a light-stimulable phosphor plate which is subsequently read out by a scanning laser beam. The imaging performance of this system has been analyzed for two types of imaging plates. The spatial resolution is described by the modulation transfer function and the signal-to-noise (S/N) ratios of the recorded image data are measured in terms of noise-equivalent quanta and detective quantum efficiency. Their dependence on detector entrance dose and spatial frequency is discussed. A detailed analysis of the different sources of image noise is given to outline the intrinsic features and limits of the system. Finally, the S/N behavior of the SPS is compared with published data of screen-film systems.