Exploring the Utility of [18F]3F4AP for Demyelination Imaging

This study is testing whether a new PET scan radiotracer — a small amount of a mildly radioactive substance injected into the body — can help detect damage to the protective covering of nerve cells (called demyelination) in conditions like multiple sclerosis. **You may be eligible if...** - You are between 18 and 89 years old - You are in generally good health - You are able to understand and sign an informed consent form **You may NOT be eligible if...** - You are pregnant or breastfeeding - You have a significant illness or unstable medical condition - You have claustrophobia or other conditions that make lying in a PET scanner difficult - You have had significant radiation exposure from research scans in the past 12 months - You have a bleeding disorder or take blood thinners Talk to your doctor to see if this trial is right for you.