Breast gamma scanning. Female patient undergoing a gamma camera scan (radionuclide scan or scintigram) of her breast to check for cancer. The gamma camera is at upper centre. Gamma scanning is a diagnostic technique involving radiation emitted by a radioactive substance passed into the body. The substance, which emits gamma rays that are detected by the gamma camera, is taken up in greater quantities by active, rapidly dividing tissue such as a cancer. Photographed at the European Institute of Oncology in Milan, Italy.