[Early diagnosis and staging of rheumatoid arthritis by MR imaging and ultrasonography].

Advanced imaging modalities, such as MR imaging or ultrasonography (US), are useful in evaluating disease activity and therapeutic outcome of rheumatoid arthritis (RA). MR imaging can demonstrate bone erosion and edema, which are important in predicting structural articular damage. MR findings are nonspecific but can be helpful in diagnosing RA in its early stage. US can access relatively easily to multiple joints, and power Doppler US allows to visualize the vascularity of synovium. Standardization of imaging and analysis procedures are needed for clinical application of these imaging modalities.