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Gamma cameras are complex mechanical and electronic products. A gamma camera must position the detector very precisely around the patient and collect a large volume of data, which is then transferred to a processing station for preparing the doctor's report.

The gamma camera is based on the Anger Principle (developed by Hal O. Anger in 1958) which in brief means that the detectors convert the radiation emitted by the tracer into carefully defined electric signals for electronic processing.

The detector is constructed of a crystal that converts the gamma photon into visible light. After this, the light is recorded by a matrix of photo multiplier tubes, which convert the signal into electrons.
As the detector must shield against radiation, the parts are mounted in a lead box. The detector alone weighs up to 200 kg and this in itself makes great demands on the mechanical design, as precise positioning around the patient is necessary to generate correct images.

Depending on the type of examination, a three-dimensional reconstruction of the organ may be required. This is done by recording a series of two-dimensional images from various angles by rotating the detector(s) 180° or 360° around the patient. The resulting series of images is then reconstructed into a 3D image.

The gamma camera must appear open and friendly to the patient, be user friendly and ergonomically correct for the operator, be as small as possible and efficient at the same time so the examination can be performed as quickly as possible.

The gamma camera is based on complicated mechanics, electrical engineering, embedded software, servo-loops, nuclear medical physics, electronic hardware and PC software.