Gamma cameras

The gamma camera is an imaging technique used to carry out functional scans of the brain, thyroid, lungs, liver, gallbladder, kidneys and skeleton.

Gamma cameras image the radiation from a tracer introduced into the patient’s body. 

The most commonly used tracer is technetium-99m, a metastable nuclear isomer chosen for its relatively long half-life of six hours and its ability to be incorporated into a variety of molecules in order to target different systems within the body. As it travels through the body and emits radiation the tracer’s progress is tracked by a crystal that scintillates in response to gamma-rays. 

The crystal is mounted in front of an array of light sensors that convert the resulting flash of light into an electrical signal. Gamma cameras differ from X-ray imaging techniques in one very important respect; rather than anatomy and structure, gamma cameras map the function and processes of the body.

 Resources

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