To identify factors that signal the transition from asymptomatic (preclinical) to symptomatic Alzheimer disease (AD).

The purpose of this research study is to evaluate the structure and function of the brain in healthy aging and early Alzheimer's disease using positron emission tomography (PET), magnetic resonance imaging (MRI), and computed tomography (CT) imaging. The study involves imaging the brain to detect the presence of amyloid deposits (plaques in the brain). Amyloid is a protein that may be related to dementia of Alzheimer's disease (DAT).

This study will use radioactive tracers called C-11 Pittsburgh Compound B (PIB) and F 18/ AV-1451 (Flortaucipir) which binds to beta amyloid and tau in the brain. These compounds are considered investigational, which means that they have not been approved by the United States Food and Drug Administration (FDA).

Inclusion Criteria:

• Male or female, any race
• Age > 18 years
• Participation in one of the ongoing projects affiliated with the Knight ADRC at Washington University and referred by the MAP staff and a Washington University physician.
• Normal cognition or early-stage symptomatic AD
• Willing and able to undergo study procedures.
• Capacity to give informed consent and follow study procedures

Exclusion Criteria:

• Has any condition that, in the Investigator's opinion, could increase risk to the participant, limit the participant's ability to tolerate the research procedures, or interfere with the collection/analysis of the data (e.g., participants with severe chronic back pain might not be able to lie still during the scanning procedures);
• Has hypersensitivity to either AV-1451 or 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;
• Currently pregnant or breast-feeding. Women must agree to avoid becoming pregnant and must agree to refrain from sexual activity or to use reliable contraceptive methods for 24 hours following administration of Flortaucipir injection;
• Must not have participated in any clinical trial involving a study drug or device within the 30-days prior to study enrollment;
• Must not participate in another drug or device study prior to the end of this study participation;
• 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

Participants are referred from the Washington University Knight Alzheimer's Disease Research Center (ADRC). The ADRC is responsible for the recruitment, enrollment, and maintenance of the Total Registry (TR). The Knight ADRC primarily recruits participants by means of word of mouth and public service announcements from the greater metropolitan St. Louis area. A small percentage (~17%) of participants are referred by a Washington University physician.

We will share imaging data with other researchers. They may be doing research in areas similar to this research or in other unrelated areas. These researchers may be at Washington University, at other research centers and institutions, or industry sponsors of research. We may also share research data with large data repositories (a repository is a database of information) for broad sharing with the research community. If individual research data is placed in one of these repositories only qualified researchers, who have received prior approval from individuals that monitor the use of the data, will be able to look at your information. The shared information will not include names but may be linked by a global unique identifier (GUID) number.