RADIOGRAPHIC IMAGING WITH IMAGE PLATES - THE INFLUENCE OF THE READOUTINTENSITY ON THE IMAGE QUALITY

The image quality of radiographic images from image plate detectors is limited by two factors: first, the quality of the image plate itself and, second, the scanning procedure of the individual scanning device. In this study the impact of the latter on the image quality is invest igated. A method to calculate the spatial resolution in the form of th e line-spread function and the photostimulated luminescence intensity for various scanning laser beam intensities is presented. Theoretical results are compared to experimental ones obtained from a commercially available image plate. It is shown experimentally that the spatial re solution is reduced with increasing laser intensity of the readout bea m, that the detected information shifts spatially and that the respons e of the photostimulated luminescence does not vary linearly with the intensity of the laser light. The results are explained by light scatt ering in the phosphor layer of the image plate and information bleachi ng during the readout procedure. (C) 1997 American Institute of Physic s.