Imaging in the preclinical phases of rheumatoid arthritis.

There is growing evidence that the development of rheumatoid arthritis (RA) is a multistep process. The European League Against Rheumatism (EULAR) identified different phases before the onset of RA, from the presence of genetic and environmental risk factors for RA, towards clinically suspected arthralgia and undifferentiated arthritis. Currently, a new definition of "window of opportunity" is emerging; this states that the window could even lie in preclinical phase of RA, preceding diagnosis or fulfillment of classification criteria for RA. In this scenario, the detection of subclinical inflammation by imaging tools could be useful together with autoantibodies and joint symptoms to better stratify people at high risk for developing RA and to plan prevention trials in high-risk cohorts. This review will give an overview on the use of computed tomography, magnetic resonance imaging and ultrasonography in the preclinical phases of RA.