Cervical rheumatoid arthritis: value of flexion and extension views in imaging.

The magnetic resonance (MR) imaging findings in the cervical spines of eight patients with long-standing polyarticular rheumatoid arthritis were reviewed. Three pathologic conditions were readily demonstrated: anterior atlantoaxial subluxation (n = 6), atlantoaxial impaction (n = 6), and subaxial subluxation (n = 6). An abnormal soft-tissue signal was noted in the preodontoid space in six patients; this signal was thought to represent the associated inflammatory mass. MR imaging was useful not only for depicting the bony abnormalities in the cervical spine that are associated with rheumatoid arthritis, but also can directly show the effect of the disease process on the spinal cord and brain stem.