Dynamic magnetic resonance tomography of the sacroiliac joints: Diagnosis of incipient signs of sacroiliitis

The investigations were carried out in 12 volunteers and 89 patients assigned to different study groups according to clinical and radiological criteria. In order to ascertain the signal intensity of the sacroiliac joints on a qualitative and quantitative basis magnetic resonance tomography was carried out using unenhanced T1-weighted spin echo sequences, unenhanced T2-weighted fast-field-echo sequences as well as a dynamic fast-field-echo sequence following intravenous administration of gadolinium diethylenetriamine pentaacetic acid. While the visualization of normal sacroiliac joints was not enhanced by the contrast medium, accumulations of gadolinium could be observed in the cavities of sacroiliac joints showing inflammatory changes. Early stages of sacroiliitis without definable pathological correlates and therefore tending to escape radiologic detection were characterized by focal contrast medium accumulations suggestive of circumscribed ostitic changes in the bone marrow closest to the affected joint. This finding was made in 83% of cases, where the joint cavities were not yet enlarged, and could no longer be observed at more advanced stages of the disease. Magnetic resonance tomography permits sacroiliitis to be detected at an extremely early stage. (orig./MG)