The Gamma camera:
The gamma camera is used to detect photons of gamma radiation from radioactive nuclei injected into the body, it can be used medical imaging to find tumors, blockages or certain types of tissue in the body.
Radioisotopes used in medical imaging are put into patients bodies and recorded on the outside using a gamma camera. Gamma radiation is used as it isn’t as ionising as Alpha or Beta but is more penetrating however, this doesn’t mean it isn’t dangerous. Radioisotopes must have a short half life, so the isotope quickly dies down after it isn’t needed to minimise exposure and so that only a small dose of the isotope is needed. Many radioisotopes are produced artificially in hospitals using a particle accelerator. The most common one is Technetium-99m (the m stands for metastable) it can be used for monitoring the functions of major organs, it loses energy in the form of gamma photons of energy 140 keV and has a half life of six hours.
Radioisotopes need to be chemically combined with elements to make sure they combine with the correct tissues and reach the correct parts of the body when injected. These radioisotopes connected with elements are designed to target the correct parts of the body and are called medical tracers or more complexly radiopharmaceuticals. They can be used in conjunction with a gamma camera to find irregularities in the function of the body.
How the Camera Works