PET scanning has an established role in a number of areas of neurological disease. The PET scan is indicated in patients in whom the diagnosis of Alzheimer's disease is under consideration but no definite diagnosis has been made. The PET scanner looks similar to a CT scanner, so claustrophobia is not a major problem.

PET scan from a patient with moderately severe dementia. This study shows reduced brain metabolism (blue areas of the scan) in the temporal and parietal lobes.