Sonography and NMR imaging in rheumatoid gonarthritis.

Sonography and NMR imaging of the knee joint make it possible to obtain a visual representation of the thickened synovial membrane occurring in patients with rheumatoid gonarthritis, even before inflammatory deformation is radiologically detectable. Both methods can expose effusions and Baker's cysts. In NMR imaging, an indication of the inflammatory genesis can be obtained from the extended relaxation time T1. Due to the good representation of soft tissues, prognostic evidence may be gained of whether a mainly exudative or proliferative form is present.