Imaging healthy volunteers and subjects with demyelinating disorders (MCI/AD/MS/SCI/SR) in the brain using [18F]3F4AP PET.

Primary Objective: An assessment of the pharmacokinetics of [18F]3F4AP in healthy volunteers and subjects with demyelinating disorders (MCI/AD/MS/SCI/SR). Correlate MR imaging with [18F]3F4AP PET imaging to assess if signal (VT or SUV) is increased in areas of demyelination compared to controls and unaffected areas of the nervous system. Evaluate associations between different imaging modalities and outcome measures (demyelination, neurometabolites, cerebral blood flow, tau burden and amyloid status) Secondary Objective (if applicable) Correlate [18F]3F4AP PET signal with impaired mental state as determined by cognitive testing. Examine the contribution of hypoperfusion and demyelination to white matter lesion detected by MR imaging Optimize MRSI sequences, image reconstruction, and data processing software for high-resolution MRSI in a subset of participants.

Eligibility Criteria

Inclusion:

Male and Female subjects must be ≥18 and <90 years of age;

Able to understand and provide informed consent prior to study procedures

Must be in good health

Exclusion:

Less than 18 years of age;

Pregnant or breastfeeding;

Any significant systemic illness or unstable medical condition;

Pre-existing medical conditions or claustrophobic reactions;

Research-related radiation exposure exceeds current PET Center guidelines (i.e. 50 mSv in the prior 12 months);

History of a bleeding disorder or are currently taking anticoagulants.