Imaging Biomarkers in Preclinical and Symptomatic AD

Inclusion Criteria: * Male or female, any race; * Age ≥ 18 years; * Active participants currently enrolled in the Knight Alzheimer's Disease Research Center (ADRC) at Washington University. Exclusion Criteria: * Hypersensitivity to \[11C\] PIB or any of its excipients; * Contraindications to PET, CT or MRI (e.g. electronic medical devices, inability to lie still for extended periods) that make it unsafe for the individual to participate; * Severe claustrophobia; * Women who are pregnant or breast-feeding will be excluded from PIB PET participation; * Has any condition that, in the opinion of the Sponsor-Investigator or designee could increase risk to the subject, limit the subject's ability to tolerate the research procedures, or interfere with collection of the data; * Currently participating in any clinical trial which involves an active study medication or placebo within the past 30 days before scanning and up to 2-weeks past the imaging visit. * Current or recent (within 12 months prior to screening) participation in research studies involving radioactive agents such that the total research-related radiation dose to the participant in any given year would exceed the limits set forth in the U.S. Code of Federal Regulations (CFR) Title 21 Section 361.1. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?FR=361.1