Doppler ultrasonography and dynamic magnetic resonance imaging for assessment of synovitis in the hand and wrist of patients with rheumatoid arthritis.

Rheumatoid arthritis (RA) activity is closely correlated with inflammation. The synovial membrane is the principal site of inflammation in which the inflammatory process enhances capillary perfusion and permeability. Doppler ultrasonography (DUS), using the amount of color pixels in the region of interest, and dynamic magnetic resonance imaging (DE-MRI), using the early enhancement rate and relative enhancement of the synovium, are both able to detect this inflammation in the wrist and hand. Although these techniques are both capable of monitoring synovium inflammation modifications after RA treatment, DE-MRI may be better for quantifying inflammation changes. It yields additional information about joint inflammation and complements clinical and biological examination, the current reference standard. DUS could become an essential tool for RA joint monitoring in routine practice in view of its sensitivity in the detection of synovitis, feasibility in outpatient clinics, and low cost, whereas DE-MRI could become a valid imaging gold standard against which other measures should be compared, especially in clinical trials.