Positron emission tomography/computed tomography imaging and rheumatoid arthritis

Rheumatoid arthritis ( RA ) is a phenotypically heterogeneous, chronic, destructive inflammatory disease of the synovial joints. A number of imaging tools are currently available for evaluation of inflammatory conditions. By targeting the upgraded glucose uptake of infiltrating granulocytes and tissue macrophages, positron emission tomography/computed tomography with fluorine‐18 fluorodeoxyglucose ( 18 F‐ FDG PET / CT ) is available to delineate inflammation with high sensitivity. Recently, several studies have indicated that FDG uptake in affected joints reflects the disease activity of RA . In addition, usage of FDG PET for the sensitive detection and monitoring of the response to treatment has been reported. Combined FDG PET / CT enables the detailed assessment of disease in large joints throughout the whole body. These unique capabilities of FDG PET / CT imaging are also able to detect RA ‐complicated diseases. Therefore, PET / CT has become an excellent ancillary tool to assess disease activity and prognosis in RA .