Beta Amyloid PET Imaging for Alzheimer Disease With [18F]-Fluselenamyl

The investigators will first complete whole-body PET dosimetry studies in healthy adult normal volunteers to calculate the actual radiation dose of each human organ and determine the allowable dose for a human subject when receiving a single dose for a PET scan.

Second, imaging of the brain and neck will be completed in a wide range of ages of healthy adult normal control participants and participants with mild cognitive impairment, both male and females to characterize 18F-Fluselenamyl uptake in the brain, its binding to beta-amyloid plaques, and radiolabeled metabolite will be completed. Amyloid is a protein related to dementia of Alzheimer's disease. 11C-PIB PET imaging and MRI of the brain will also be completed in the same participants and the data will be compared with 18F-Fluselenmayl. 11C-PIB and 18F-Fluselenamyl both bind to beta-amyloid plaques.

Finally, a comparison of the normal control participants to patients with Alzheimer's disease will be completed.

Inclusion criteria

• Male or Female, any race
• Age ≥ 18 years
• Healthy volunteers or volunteers with Alzheimer's disease

Exclusion criteria

• Has hypersensitivity to 18F-Fluselenamyl or any of its excipients ;
• Has hypersensitivity to 11C-PIB or any of its excipients ;
• Incapable of providing written informed consent or lacking a legally authorized representative (LAR) to provide informed consent ;
• Unwilling or unable to undergo PET scans tracer injections ;
• Unwilling or unable to undergo MRI (Aim 2 and Aim 3)
• Any condition that, in the Investigator's opinion, could increase the 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., renal or liver failure, advanced cancer);
• Women who are currently pregnant or breast-feeding;
• 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.