Features of rheumatoid arthritis best demonstrated with MRI include :

• synovial hyperemia: an indication of acute inflammation

• synovial hyperplasia (rice bodies)

• pannus formation

• decreased thickness of cartilage

• subchondral cysts and erosions:

  • MRI is much more sensitive than radiography

    • it is thought that subchondral cysts in rheumatoid arthritis eventually progress to erosions (i.e. constitute "pre-erosions")

  • contrast enhancement may distinguish erosions or pre-erosions from degenerative subchondral cysts

• juxta-articular bone marrow edema

• joint effusions