A painless, non-invasive way of creating images of the brain.
PET works by detecting the radiation produced by a substance called a radiotracer. A radiotracer is injected into a vein in the patient’s arm or hand before the scan.
In the dementia diagnosis process, PET scans are used to detect the presence of proteins called amyloid and tau. Amyloid and tau build-up happens when a person is developing Alzheimer’s disease, which is the most common cause of dementia.    Preparing for the scan
The patient will be advised to fast for 6 hours before the scan, although they may still drink water.    In addition, patients should remove any metallic objects that may interfere with the scan.    About an hour before the scan, a radiotracer will be injected into a vein in the patient’s arm or hand. Patients will then stay still and relax as the radiotracer travels to different parts of the body.     During the scan
After the patient has been given the radiotracer and an hour has passed, the PET scan will begin.    PET scans last for about 30 to 60 minutes, during which patients should lie still.