An MRI Study of Bone Erosions Healing in the Wrist and Metacarpophalangeal Joints of Patients with Rheumatoid Arthritis

Bone erosions, considered the hallmark of rheumatoid arthritis (RA), are shown more accurately by MRI than by conventional radiography (CR). Erosions healing is exceptional when studied by CR. This study is concerned with an extremity-dedicated MRI evaluation of erosion changes in patients with RA followed over time. Wrist and metacarpo-phalangeal (MCP) joints of 57 RA patients were imaged with a dedicated-extremity, 0.2 T MRI at baseline and follow up. A decrease of the RAMRIS erosion score indicating erosion healing, calculated both by conventional visual judgement and by a semi-automated method, was seen in 7 (12.3%) patients at the wrist and in 3 (5.3%) at the MCPs. In the same locations, RAMRIS was unchanged in 17 (29.8%) and 31 (54.4%) patients, and worsened in 33 (57.9%) and 17 (29.8%), respectively. Healing of erosions occurs, although rarely, in patients with RA when studied with sensitive imaging techniques, such as MRI.