Since MR imaging directly visualizes all articular components with excellent contrast resolution, it allows the joint to be viewed as a whole organ. An increasing aggressive therapeutic strategy has attracted growing attention to the potentials of MR imaging in the diagnosis, prognostication, and outcome measure of RA. The introduction of MR imaging into the diagnostic criteria for early RA contributes to more accurate diagnosis in patients suspected of having RA and thus allow an earlier decision to start proper medication. Quantification of inflammatory synovitis by MR imaging can assess treatment outcome in fewer subjects than with traditional measures. We believe MR imaging can be cost-effectively incorporated in the treatment trial.