Amyloid Plaque and Tangle Imaging in Alzheimer's Disease and Down Syndrome

The purpose of this study is to develop small molecule radio-labeled probes of beta-amyloid, to be used with positron emission tomography (PET) for early detection and treatment monitoring of Alzheimer disease (AD). The study hypothesis is that PET imaging of small molecule probes, in the form of novel fluorescent dyes with radioactive labels, will demonstrate cerebral patterns in patients with AD that are distinct from those of age-matched persons who are cognitively intact.