[MRI examinations for axial and peripheral spondyloarthritis]

The diagnosis of ankylosing spondylitis (AS) is based on the modified New York criteria and therefore on defined structural changes in the sacroiliac joint as detected by conventional radiographs. However, x-rays are not able to detect early stages of the disease in which inflammation predominates and irreversible structural changes have not yet taken place. This probably contributes to a substantial time delay until a diagnosis is made. Magnetic resonance imaging (MRI) is able to visualize active and chronic changes in axial and peripheral spondyloarthritis (SpA) even before the occurrence of structural changes. The ability to demonstrate both active and, in a limited way, also structural changes makes MRI a diagnostic tool of increasing importance in the management of SpA. However, conventional radiographs are still the gold standard for the assessment of structural changes in SpA. A combination of both imaging techniques is recommended in clinical practice.