Radionuclide scanning is used both to image structures and to assess their function. In most cases, an injection of a radioactive substance (radionuclide) is given before the scan, but you may be asked to inhale radioactive gas if your lungs are being scanned (see Radionuclide lung scanning). The choice of radionuclide depends on the structure being imaged. During the scan, you lie still on a motorized bed and the radiographer moves you and a camera into position. The camera detects radiation emitted by the radionuclide, and a computer builds up an image.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.