[Rheumatoid arthritis of the craniocervical transition. Detection of inflammatory changes in contrast CT and MRI]

A total of 136 patients with rheumatoid arthritis underwent MRI with sagittal T1-weighted spin echo sequences before and after i.v. administration of Gd-DTPA and with a 15-min delay. In addition, T2-weighted gradient echo sequences were performed. Conventional radiographs, including tomography in sagittal and a.p. planes, were also taken of all patients; 51 were also examined by CT before and after i.v. administration of contrast medium and in addition with a 15-min delayed series. The signal intensities of MRI and the changes in density caused by contrast uptake on CT were examined visually and measured quantitatively. The inflammatory changes were classified in four phases by the MRI and CT findings and histological results. A correlation (p < 0.05) was found with the erythrocyte sedimentation rate. MRI was superior to CT in 10% of cases. A discrete effusion in the anterior junction was missed in 4 cases and a hypervascular pannus formation in 1 case by CT. The CT was superior to the other methods in detecting bony lesions and calcifications in the atlantödental region. The local activity of the inflammatory changes can be graded by classifying them with contrast-enhanced MRI and CT, which yield an exact result for better monitoring during therapy.