Abstract
This article reviews the parameters that characterise the image quality of digital radiography and the available evaluation methods that are used to measure these parameters. The article also discusses the factors that aff ect eachparameter of image quality. Digital imaging systems are the most commonly utilised technology in the field of radiology. Screen-film radiography systems are almost replaced by digital radiography. The data acquisition and image processing principles of digital radiography diff er from that of conventional radiography. The required exposure factors for eachdigital radiography system are not the same. Therefore, the image quality should be optimised while lower radiation dose is maintained according to the properties of the specific imaging system. Distinguishing image quality parameters and understanding the factors that control eachimage quality parameter are essential to optimise and maintain image quality and to reduce radiation dose to the patient. The degree of factors eff ects on the images of diff erent digital radiography types and systems are not exactly same. There are diff erent methods and approaches that are used to evaluate the quality of medical images and to assess the performance of imaging systems and eachhas its own rewards and limits. Therefore, these methods should be utilised and employed according to their aptitudes to improve imaging process.