Computed Radiography: Physics and Technology

This chapter describes the essential physics and technical considerations of computed radiography (CR). Firstly, a brief history of CR is reviewed including terms synonymous with CR, followed by a description of three main processes involved in CR including image acquisition, image processing, and image display, storage, and communication. Secondly, the basic physics of CR is described focusing on the nature of photostimulable storage phosphor (PSP), latent image formation and photostimulable luminescence (PSL), and PSL characteristics. Thirdly, the major topic outlined is the technological aspects of CR. These include the structure of CR imaging plate (IP), the IP imaging cycle, CR reader types and scanning technologies, features of the CR workstation, and computer networking and CR. Furthermore, image processing is elaborated and described in terms of pre-processing and post-processing operations. Fourthly, radiation exposure control in CR is explained in terms of the IP response to exposure, exposure indicators, and exposure indicator guidelines. Fifthly, an important topic described in this chapter deals with image quality descriptors including spatial resolution, density resolution, noise, and detective quantum efficiency. In addition, an overview of the nature of CR image artifacts is briefly reviewed. The final topic included in this chapter addresses continuous quality improvement (CQI) which includes quality assurance (QA) and quality control (QC).