MR-IMAGING IN SERONEGATIVE SPONDYLOARTHRI TIDES

In twenty-five patients with a clinical diagnosis of suspected sacroil iitis conventional radiography, CT and MRI were performed. In ten pati ents no abnormalities were demonstrated. In thirteen cases CT and MRI revealed sacroiliitis. In two patients with normal plain films and CT para- and intraarticular changes of signal intensity suggested suspici ous sacroiliitis. MRI can be considered as an important imaging modali ty for early diagnosis of sacroiliitis. In eighteen patients with a fi rm diagnosis of ankylosing spondylitis and plain films of the thoracol umbar junction suggesting destructive Romanus and Anderson inflammator y lesions MRI was done. Two distinct groups of inflammatory changes we re found. In ten patients MRI findings compatible with active inflamma tory enthesitis were revealed at the disco-vertebral junction. In eigh t cases focal and linear changes of signal intensity within the interv ertebral disks suggested an active inflammation. Using MRI the spectru m of inflammatory changes in sere-negative spondylitis can be presente d. In sixteen patients with definite clinical diagnosis (psoriatic art hritis - thirteen cases and Reiter's syndrome - three cases) plain fil ms and MRI of small hand joints were performed, The patients fell into two distinct groups. In the first MRI findings could not be different iated from those seen in rheumatoid arthritis. In nine cases the distr ibution and extent of soft tissue findings were different, similar to changes seen in enthesitis. Therefore, on the basis of MRI findings in small peripheral joints easier differential diagnosis between sere-ne gative spondyloarthritides and rheumatoid arthritis is possible, In fi ve patients with a diagnosis of Reiter's syndrome having clinical sign s of enthesitis plain films and MRI of calcaneus were done, MRI reveal ed findings compatible with active inflammation which resembled those seen at the attachment of the annulus fibrosus and collateral ligament s of the small hand joints.