[18F]SF12051 for Imaging the 18-kDa Translocator Protein (TSPO) in Brain and Whole Body of Healthy Subjects

Background: Inflammation in the brain plays a role in many diseases. Being able to measure inflammation in a person's brain might help to diagnose and treat these diseases. One protein (TSPO) appears in higher numbers when inflammation affects the brain. To see TSPO when a person's body is scanned, researchers need a substance called a radiotracer that will attach to this protein and no other molecules. Objective: This study will test whether a new radiotracer (\[18F\]SF12051) can make TSPO appear on PET scans of a person's brain and body. Eligibility: Healthy people aged 18 and older. Design: This study requires 2 to 4 visits to the clinic. All participants will be screened. They will have a physical exam. They will have blood tests and a test of their heart function. Some participants will have a positron emission tomography (PET) scan of the whole body. The radiotracer will be injected through a tube (catheter) placed in a vein in the arm. The PET scanner is a machine shaped like a doughnut. Participants will lie on a bed that slides in and out of the scanner. The scan will take about 2 hours. Some participants will have a PET scan of just their head. After they are injected with the radiotracer, they will lie on a bed with their head in the scanner. Blood will be drawn from a catheter in the wrist during the scan. Some participants will have a magnetic resonance imaging (MRI) scan of the brain. They will lie on a narrow bed that slides into a tube.