The emerging digital radiology

Abstract

The evolution of radiological digital techniques in the last decades is analysed taking into account the different approaches from the image intensifier tube to the modern amorphous-selenium area detectors. The important properties of image detectors in the perspective of fulfilling the needs of images in radiology (field coverage, geometrical characteristics, quantum efficiency, detector thickness, dynamic range, noise, detector extrinsic efficiency, detector total efficiency and detective quantum efficiency) are considered. Some relevant points associated with information transfer are referred with some detail. The response characteristics of the presently available systems in terms of detective quantum efficiency are analysed and it is showed that amorphous silicon solid-state detectors are the most appropriate.