Testing and disclosures related to amyloid imaging and Alzheimer's disease: Common questions and fact sheet summary

Alzheimer's disease research has often focused on the molecular brain changes that promote memory loss and other dementia-related cognitive impairments. Many studies, for example, have used positron emission tomography (PET) imaging to measure brain levels of the beta-amyloid protein, a key molecular suspect in Alzheimer's. In recent years, PET scans have become more prominent in clinical settings. Clinicians may use a positive PET scan-that is, a significant presence of beta-amyloid plaques in the brain-to help determine a diagnosis of Alzheimer's disease. Yet, because beta-amyloid PET remains a fairly new diagnostic tool, physicians and patients still have many basic questions about how and why it is used. This article addresses some of those questions. It explains what PET scans actually show, how they are employed in research and clinical trials, and when they should and should not be used to help diagnose Alzheimer's in everyday patients. The article also discusses whether cognitively healthy people should request PET scans to assess their risk for developing dementia. Information in the text will be updated in future years, as diagnostic imaging techniques for Alzheimer's disease continue to evolve.