Control of scattered radiation, X-ray tables and ‘bucky’ stands

Abstract

As radiation traverses the patient’s tissues during a diagnostic exposure it is attenuated by the processes of photoelectric absorption and compton scatter. The processed radiograph is a pattern of densities forming a shadow image of the structures penetrated by the radiation. The extent to which the radiation is absorbed is determined by the atomic number of the tissues encountered. Bone, for example (atomic number 14), absorbs more radiation than soft tissue (atomic number 7.4) or fat (atomic number 6.0). The image is formed by emergent primary radiation reaching the film. Contrast is determined partly by the extent to which primary radiation penetrates the various body structures and partly by the effects of scatter.