A multireader reliability study comparing conventional high-field magnetic resonance imaging with extremity low-field MRI in rheumatoid arthritis.

The use of extremity low-field magnetic resonance imaging (E-MRI) is increasing, but relatively few data exist on its reproducibility and accuracy in comparison with high-field MRI, especially for multiple readers. The aim of this multireader exercise of rheumatoid arthritis wrist and metacarpophalangeal joints was to assess the intermachine (high vs low-field) agreement and to assess the interreader agreement on high and low-field images. Study findings suggested that E-MRI performs similarly to conventional high-field MRI regarding assessment of bone erosions. However, for synovitis and bone edema, considerable intermachine and interreader variability was found. Further studies are needed before recommendations on multireader E-MRI assessment of these pathologies can be given.