F 18 T807 Tau PET Imaging of Alzheimer's Disease

Inclusion criteria

• Male or female participants, at least 18 years of age.
• Cognitively normal, or with mild dementia, as assessed clinically
• Participant is able and willing to undergo testing (MRI or CT, PET, radioactive tracer injection, LP; for those unable to undergo an MRI, CT will be used to generate regions-of-interest).
• Pre-menopausal women will undergo a urine pregnancy test within 24 hours of drug administration.

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 experimental procedures, or interfere with the collection/analysis of the data (for example, participants with severe chronic back pain might not be able to lie still during the scanning procedures).
• Is deemed likely unable to perform the imaging procedures for any reason.
• Has a high risk for Torsades de Pointes or is taking medications known to prolong QT interval.
• Has hypersensitivity to F 18 T807 or any of its excipients.
• Contraindications to PET, PET-CT or MR (e.g. electronic medical devices, inability to lie still for long periods) that make it unsafe for the individual to participate.
• Severe claustrophobia.
• Currently pregnant or breast-feeding.
• For those electing to undergo the optional lumbar puncture: currently on anticoagulant of any form -