Radiographic image quality as perceived by radiologists and medical practitioners in general depends on the anatomical and diagnostic information conveyed by the image. This in turn depends on reader training and the physical factors that affect displayed information content — contrast, spatial resolution, noise and artifacts. A lesion is easy to see if its gray scale difference with the surround is great and if its borders are abrupt and not degraded by noise gray scale fluctuations and artifacts. The advances in image quality that have occurred in the last twenty five years are reviewed and are attributed to two major factors — the shift from screen-film to digital radiography, and the wide spread adoption of systematic quality control. These advances and their impact on anatomical and diagnostic information content are reviewed. Also reviewed are the areas where there has been little or no change (and occasionally a degradation) in the factors that determine image quality. Radiographic techniques, image spatial resolution, image receptor DQE, and scatter control techniques employed today are not markedly different than in the early 1980s. The advances in and the current limitations of anti-scatter grid technology are reviewed. Also reviewed is the IEC standard for evaluating grid performance. It is concluded that even though radiographic image quality has improved, and in certain cases markedly, in the past twenty five years, further improvements are still possible.
Barnes, G,
Physics Keynote Speaker: Diagnostic Radiography—Advances in Image Quality. Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL.
http://archive.rsna.org/2007/5017025.html
