Arthritis

More localised infectious or (in a later stage) more generalised inflammatory arthritis are initially sometimes difficult to diagnose and to differentiate. The 3D imaging of MRI eliminates the bony superposition, gives an objective idea of the width of the joint spaces, and visualises directly in high contrast the soft tissues and bone marrow. It therefore substantially contributes to the (differential) diagnosis. In RA, the wrist is frequently affected and is also a good marker for the general joint involvement. Standard views will only show irreversible destructive bony erosions and soft tissue swelling. MRI, on the other hand, may show BMO as a precursor of erosions, IA fluid, synovial proliferation with bone and cartilage destruction, active zones of osteitis, tenosynovitis, tendon laceration or rupture, and ligament lesions. Peri-articular CE on MRI has a sensitivity of about 100% and a specificity of about 89% for RA. The illustration of areas of carpal BMO, hydrops in multiple compartments, and (extensor and flexor) tenosynovitis may be misleading and due to other inflammatory pathology.