To quantify the activity of joint inflammation with magnetic resonance (MR) imaging and positron emission tomography (PET).
Gadolinium-enhanced MR imaging and 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) PET of the wrist were performed prospectively in 12 patients receiving antiinflammatory therapy. Patients were studied three times: off medications for 2 weeks, after 2 weeks of treatment with prednisone or nonsteroid antiinflammatory drugs, and after 12 weeks of treatment with methotrexate. Volume of enhancing pannus (VEP) was determined from fat-suppressed MR images (12 patients). FDG uptake was calculated from PET images (11 patients).
VEP and FDG uptake were closely correlated (r > .86, P < .0001), as were changes in VEP and standardized uptake volume (r > .91, P < .0002). VEP and FDG uptake were strongly associated with clinical findings in wrists (P < .002) but not with treatment outcomes (P > .05).
Contrast material-enhanced MR imaging and PET allow quantification of volumetric and metabolic changes in joint inflammation and comparison of efficacies of antiinflammatory drugs.