n. a substance that produces a fluorescent flash when struck by high-energy radiation, such as beta or gamma rays. In medicine the most commonly used scintillator is a crystal of thallium-activated sodium iodide, which forms the basis of a *gamma camera. See also scintigram.
an apparatus that detects gamma rays emitted by radioactive isotopes that have been introduced into the body as *tracers. It contains an activated sodium iodide crystal (see scintillator) and a large array of photomultiplier tubes. Using lead *collimators, the position of the source of the radioactivity can be plotted and displayed on a TV monitor or photographic film (see scintigram).... gamma camera
n. a diagram showing the distribution of radioactive *tracer in a part of the body, produced by recording the flashes of light given off by a *scintillator as it is struck by radiation of different intensities. This technique is called scintigraphy. By scanning the body, section by section, a ‘map’ of the radioactivity in various regions is built up, aiding the diagnosis of cancer or other disorders. Such a record is known as a scintiscan. These images are now usually obtained using a *gamma camera.... scintigram