Ultra low field MR imaging of cervical spine involvement in rheumatoid arthritis.

In a study of 30 patients with longstanding rheumatoid arthritis the diagnostic usefulness of ultra low field MR equipment was analyzed in assessing lesions of the craniocervical junction. It was found that at 0.04 T all the examinations were diagnostic and that in combination with plain radiography the diagnostic information obtained was valuable in further planning of the treatment strategies. The neurologic findings were related to the degree and severity of atlantoaxial luxation, either horizontal or vertical, and to the periodontoid pannus formation. The correlation between the degree of cord compression shown with MR imaging and the clinical symptoms, especially long tract symptoms, was poor. The only correlating factor was the duration of the disease.