|How images are obtained|
Radiographs, or x-rays, are images which are obtained using ionizing radiation. A beam of radiation passes through a patient, to hit a specialized detector. Traditionally, an image is created and printed on film. More currently, radiography has become digitalized and the images are viewed on specialized computer workstations.
X-rays are discrete quantities of electromagnetic radiation. X-rays are produced in a generator by the interaction of an electron beam with a Tungsten target. The resulting x-rays which are produced are emited from the generator as a beam directed towards a specialized detector, called a cassette.
The cassette contains film and intensifying screens. When the x-rays hit the film, a photochemical interaction occurs, causing the metalllic silver in the film to precipitate. This renders the film black when it is developed chemically.
The patient stands between the generator and the cassete. Tissues of the body absorb, or attenuate, some of the x-rays, while others pass through and hit the cassette. The film appears black in areas where the x-ray beam was not absorbed.