The scintillation or gamma camera is an imaging device which captures the presence of certain radioactive isotopes in a process called scintigraphy. For the most part these machines are used in much the same way as magnetic image resonance or other human tomographic investigations.
The physical structure of the device is quite similar to a dentist’s x-ray in appearance, with a main gantry supporting the head of the imaging assembly. This head is made up of several crystal planes which are coupled to a photomultiplier tube, and the entire device is hooked up to a computer.
The software contained within the computer is used to interpret, enhance, and then graphically represent the incoming data stream. When radioactive isotopes are emitted towards the collection head, a thallium doped flat sodium iodide crystal collects these emissions and begins to scintillate.
Scintillation is a process of luminescence in which the absorption of radiation causes a flash of light. This is an inherent property of many organic compounds, and has been demonstrated in some inorganic things such as various salts and gases.
Because of this concept of scintillation and the way in which a light sealed sodium iodide crystal can be used to collect, count, and relay event occurrences to the software, it is able to be used in many ways. The primary use still revolves closely around the idea of imaging the human body, however. By studying the distribution of certain appropriate radionuclides such as Barium-133 or Cobalt 60, a trained operator can draw certain conclusions about things like cardiac stress testing.
Although it is less sensitive than dedicated PET scanner, a gamma camera has the advantage of being cheaper and more flexible in its potential application. This trade off is frequently acceptable to researchers who do not require highly specialized imaging equipment but instead need to study organic and inorganic subjects equally.