What are the MRI manifestations of spinal rheumatoid arthritis?

MRI manifestations of spinal rheumatoid arthritis are as follows: ① facet dislocation or subluxation, including atlantoaxial joint anterior dislocation, odontoid process upward displacement, lateral mass displacement of atlas, atlantoaxial joint posterior dislocation and subaxial subluxation. ② Synovial pannus formation is most common behind odontoid process, with moderate signal on t 1 weighted images and high or moderate signal on T2-weighted images. ③ Bone erosion, which is common in the anterior articular surface of odontoid process. ④ Intervertebral facet joints can also have abnormal manifestations.