Short-term Repeat Magnetic Resonance Imaging Scans in Suspected Early Axial Spondyloarthritis Are Clinically Relevant Only in HLA-B27-positive Male Subjects

Objective. Our study investigated the natural history of magnetic resonance imaging (MRI)-determined bone marrow edema over a 12-week period in individuals with suspected axial spondyloarthritis. Methods. There were 109 MRI scans performed on 30 patients who fulfilled the Assessment of Spondyloarthritis international Society inflammatory back pain criteria at baseline and at 4, 8, and 12 weeks. Results. There were 29 patients who completed the study. Only 4 (14%) patients changed from MRI-negative to MRI-positive (all HLA-B27-positive, OR 2.74). Three of 7 (43%) male HLA-B27-positive patients, 1 of 8 (12.5%) HLA-B27-positive female patients, and no HLA-B27-negative patients changed from MRI- negative to -positive. Conclusion. Repeat MRI scans within a 12-week period should be considered in HLA-B27-positive males.