Imaging in Alzheimer Disease
Functional imaging has recently emerged as a critical tool in understanding changes in the brain of individuals with memory loss and problems with thinking. Functional imaging using FDG PET has been available for several years and provides information about the metabolisms of the specific areas of the brain. FDG PET can be especially useful in differenting a diagnosis of Alzheimer disease from frontotemporal dementia.
A major advancement in Alzheimer disease research has been the development of amyloid imaging. It is well recognized that individuals with Alzheimer disease have an accumulation of a protein called amyloid in the brain. Several therapies aimed at slowing the progression of Alzheimer disease by reducing amyloid deposition are being testing in clinical trials. Imaging to detect amyloid in the brain is available in research settings and provides information that is used in conjunction with clinical evaluations. Amyloid imaging may be useful in clarifying a diagnosis of Alzheimer disease and differentiating this from other forms of dementia.
An example of amyloid imaging is provided in the figure below. In this figure, there is increased activity (bright red and yellow) in the patient with Alzheimer disease representing the presence of amyloid in the brain compared to relatively no activity in the healthy control image.