What are PET Scans?
Positronic Emission Tomography, or PET, is a technique used commonly for imaging the brain. In PET scanning, positively charged ions or positrons are injected into the patient’s bloodstream. Inside the body these positrons are taken up by those areas of the body that are metabolically active. This means in these areas these positrons are taken up by the cells and the natural chemical reactions occuring inside the cell causes photons (light) to be released. These photons are detected by the PET scanner and an image is produced on a computer screen. PET scans are able to show the areas of a organ that are chemically or metabolically active. If the positrons introduced are oxygen atoms then a PET scan can show the comsumption of oxygen in certain parts of the brain. Areas that are deprived of their blood supply, and therefore oxygen, will show up and can be detected by the specialist viewing the scan. This is sometimes used in stroke patients to show up the parts of the brain affected by
