Gamma cameras detect radioactive gamma rays, and are commonly used by doctors looking for cancer in patients. They work in similar fashion to an x-ray machine, and are used to scan the internal organs for radioactive matter.
Although radiation was first discovered in 1896, the gamma ray camera wasn't invented until 1958.
Radioactive tracers, such as thallium, are released into the patient's bloodstream by means of an IV drip. The tracers release radiation, which is picked up by a gamma ray camera. Physicians use the gamma camera to look for abnormalities such as cancer.
Gamma cameras absorb the gamma rays with a crystal, which produces a flashing light on a connected computer screen. Highlighted areas on the screen indicate problem areas that may need to be further investigated by an oncologist (cancer specialist).
While the entire examination process may take up to three hours, the actual scanning time from the gamma camera normally takes around 20 minutes.
Gamma cameras are also known as Anger cameras, after their inventor, Hal Anger.