Opinion: Perspectives on imaging in axial spondyloarthritis.

The diagnosis of axial spondyloarthritis (axSpA) is based on detection of characteristic inflammatory or structural changes (or a combination of both) in the spine and sacroiliac joints. Imaging of the axial skeleton is, therefore, useful for the identification of these pathological changes. Both inflammation (best detected by MRI) and bone formation (best visualized by conventional radiography) can predict the development of future structural changes. In addition, a high degree of spinal inflammation on MRI is predictive of a successful response to anti-TNF therapy. Emerging data indicate that the combination of acute and chronic changes on MRI has an important influence on progression of nonradiographic axSpA to ankylosing spondylitis. This Perspectives article provides an overview of the role of imaging in the diagnosis and management of axSpA, and also discusses open questions and future perspectives in this field.