The role of imaging in rheumatoid arthritis.

Conventional radiographs of the hands and feet have traditionally been used in the diagnosis, management and monitoring of patients with rheumatoid arthritis (RA). However, they are not sensitive enough to detect changes early in the disease process. Erosions may only be visible up to two years after the onset of disease, and soft tissue involvement may not be detected at all. Early diagnosis can also be made challenging as markers such as erythrocyte sedimentation rate and C-reactive protein may be normal in up to 20% - 25% of cases. The latest classification criteria (American College of Rheumatology/European League Against Rheumatism [ACR/EULAR] Rheumatoid Arthritis Classification criteria 2010), often used to diagnose RA, incorporate the role of ultrasound and magnetic resonance imaging detection of synovitis, enabling earlier diagnosis and correct classification of patients. This article looks at the role of the various imaging modalities used in the diagnosis and management of RA.