[Integrated role of computerized tomography and magnetic resonance imaging in identifying the early changes in rheumatoid arthritis of the craniocervical junction].

Any cervical spine segment may be affected by rheumatoid arthritis, but destructive changes are most prominent at the craniocervical junction. Cervical involvement is a devastating complication of the disease, because of the risk of a range of neurological complications (paresthesia, cervical myelopathy, vertebro-basilar insufficiency), and even sudden death from medullary compression. However, the incidence of both cervical rheumatoid arthritis and its neurological complications are still debated, being respectively reported in 17-86% and 11-70% of the patients, according to the variability in neurological and radiologic classification systems adopted by the authors. To assess the incidence of cervical rheumatoid arthritis and the integrated role of different imaging techniques in its diagnosis, 38 consecutive patients (29 women and 9 men) with rheumatoid arthritis according to the American Rheumatism Association criteria were examined. The average age was 60 years (range: 27-70 years) with a mean disease duration of 6.6 years (range: 6 months-25 years). All the patients underwent conventional radiography of the cervical spine, unenhanced Computed Tomography (CT) of the craniocervical junction and unenhanced and Gadolinium-enhanced Magnetic Resonance Imaging (MRI) of the cervical spine. Cervical spine involvement was demonstrated in 25/38 (66%) patients 20 women and 5 men, with an average age of 57 years and a mean disease duration of 8.5 years. In 13 of them (mean disease duration: 12.7 years), the diagnosis was made with radiography which showed atlantoaxial and subaxial subluxations and/or erosions. Of the 12 patients with negative conventional radiography (mean disease duration: 2.5 years), 4 were identified with both CT and MRI (synovial pannus and erosions). 3 with MRI only (joint effusion/hypervascularized synovial pannus), and 5 exhibited questionable CT findings which were clarified only by MR demonstration of inflammatory tissue contiguous to suspicious irregularities of the cortical bone of the odontoid process. 52% (13/25) of cervical rheumatoid arthritis patients were identified with plain radiographs, 68% (17/25) with CT and 100% (25/25) with MRI. Our preliminary data show that a specific tool for the diagnosis is recommended even in the early disease phases since rheumatoid arthritis commonly affects the craniocervical junction. Studying the craniocervical region is clinically difficult, and diagnostic imaging assessment is essential. Conventional radiography allowed to detect more than half the patients with cervical rheumatoid arthritis, but only in advanced disease stages. On the contrary, MRI had the unique potential of direct and detailed synovial visualization, thus permitting the diagnosis of cervical involvement even in the early phases of the inflammatory process, when CT findings were still negative or questionable.