The discriminatory capacity of ultrasound in rheumatoid arthritis: active vs inactive, early vs advanced, and more.

This review presents data about the discriminatory role of US in differentiating findings between healthy people and patients with RA and arthritides, comparisons between active and inactive changes in RA, as well as between early and advanced changes in RA as visualized with US. The theoretical basis of discriminatory capacity is sketchy and the few studies that provide evidence of its use when assessing RA patients with US are discussed. We also suggest directions for potential research areas.