(also gamma scanner), an instrument for the automatic recording of the intensity distribution in any organ of the radiation from a radioactive preparation that has been introduced into the organism for diagnostic purposes. Types of gamma scintigraphs include all-purpose scanners, for all aspects of gamma scintigraphy; scanners with a field of 40 × 40 cm, for the examination of individual parts of the body; and specialized scanners, with two detectors and a complicated scanning program (arcs of variable length), for diagnosing brain tumors.
A gamma scintigraph consists of a gamma-radiation detector (counter), which is moved over the patient along lines or arcs by an electronic device that converts the counter’s signals into a form suitable for recording. Depending on the instrument’s design, the recording may be in the form of simple dashes on paper through a carbon paper or a typewriter ribbon, a photographic recording by means of a light source on photographic film or X-ray film with an undeveloped X-ray picture of the irradiated region of the body (combined X-ray and gamma-ray scintigrams), recording on magnetic tape with subsequent processing of data, or multicolored dashes or luminous marks. The information thus obtained (the scintigram) makes it possible to make a judgment concerning the shape, position, dimensions, and functions of an organ.