PET Imaging Study Using [11C]PIB in Subjects With AD & Healthy Volunteers

Inclusion Criteria: * Male or female subjects at least 18 years of age * Subjects who in the opinion of the investigator based on medical history and physical exam can tolerate the PET scan procedures Exclusion Criteria: * Have clinically significant hepatic, renal, pulmonary, metabolic, or endocrine disturbances * Have current clinically significant cardiovascular disease. * Have a history of drug or alcohol abuse within the last year, or prior prolonged history of abuse * Have a clinically significant infectious disease, including Acquired Immune Deficiency Syndrome (AIDS) or Human Immunodeficiency Virus (HIV) infection or previous positive test for hepatitis * Women of childbearing potential must not be pregnant (negative urine beta-hCG at the time of screening and negative urine beta-hCG on the day of imaging) or lactating at screening or at day of imaging * Have a history of relevant severe drug allergy or hypersensitivity (Relevant severe drug allergies should be determined by the PI, and any questions about a subject's eligibility can be directed to Avid. If a subject has a history of severe drug allergies, it may be dangerous for them to participate in a study with a novel compound * Have received an investigational medication within the last 30 days. Current clinically significant or unstable medical comorbidities, as indicated by history or physical exam * Have received a radiopharmaceutical for imaging or therapy within the past 7 days prior to the imaging session for this study * Body weight \> 300 pounds * History of significant radiation exposure * Participants with pacemakers, implanted electronic hearing devices, aneurysm clips, shrapnel, unallowed prosthetic or other metallic device in their bodies * Pre-existing CNS disease (other than dementia), endocrine, or severe cardiovascular disease (MI, CABG, angioplasty)