The overall goal of the Amyloid PET Early Frames study is to determine if blood flow in the brain, measured by PET early frame measurements, can be used as a measure of cognitive decline. This project proposes to do this by measuring the spread of a PET tracer in subjects’ brains immediately after introduction into the body. This will be done in 100 subjects at two different time intervals, 2 years apart, to assess differences over time. Additionally, the subjects will be split among healthy controls and individuals with Mild Cognitive Impairment (MCI) to understand differences in the two populations. This project will leverage the Alzheimer’s Disease Neuroimaging Imitative 3 (ADNI 3), which is an Alzheimer’s Disease (AD) natural history study that has been ongoing for over 16 years with a wealth of available subject information and data, which will be crucial to the success of the project. If successful, this project could reduce patient burden in AD clinical trials by eliminating the need for a separate FDG PET scan, thus minimizing trips to the clinic and unnecessary radiation exposure. This would also benefit drug development, as it would reduce clinical trial costs and enable funds to be spent on additional patients or other trials.