[11C]MC1

Background:
Inflammation plays a significant role in various disorders that involve neurodegeneration or autoimmune reaction as one of their mechanisms. PET scans can help detect inflammation. Two new drugs may create better PET images.
Objective:
To see if the drug [11C]MC1 can help image inflammation.
Eligibility:
People ages 18 and older with rheumatoid arthritis or idiopathic inflammatory myopathy (IIM).
Healthy volunteers enrolled in protocol 01-M-0254 or 17-M-0181 are also needed.
Design:
Healthy participants will be screened under protocol 01-M-0254 or 17-M-0181.
Participants with arthritis or IIM will have a screening visit. This will include:
Medical history
Physical exam
Blood and urine tests
Possible CT or X-ray: A machine will take pictures of the body.
Healthy participants will have 1 or 2 visits. They may have urine tests. They may take the drug celecoxib by mouth. They will have a PET scan. A small amount of one or both study drugs will be injected through a catheter: A needle will guide a thin plastic tube into an arm vein. Another catheter will draw blood. They will like on a bed that slides into a machine. Their vital signs and heart activity will be measured.
Participants with arthritis will have up to 2 visits after screening. They may take celecoxib and have PET scans.
Participants with IIM will have up to 3 visits after screening. At 1 or 2 visits, they will take celecoxib and have PET scans. They will have 1 visit where they have an MRI: They will lie on a table that slides into a machine. The machine takes pictures of the body.