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

This study tests a new radioactive imaging agent called [18F]-Fluselenamyl that can detect beta-amyloid plaques in the brain — the protein build-up associated with Alzheimer's disease. Researchers will compare it to an existing approved imaging agent to see how well it works. **You may be eligible if...** - You are 18 years old or older, of any race or gender - You are either a healthy volunteer or someone with Alzheimer's disease **You may NOT be eligible if...** - You have a known allergy to the imaging agents used in this study - You are unable to provide consent or cooperate with the scanning procedure Talk to your doctor to see if this trial is right for you.