The reflection of disease progression in axial spondylarthritis to the imaging

Spondyloarthritis (SpA) is currently evaluated as predominantly peripheral or axial according to the current classification. The definition of axial SpA (axSpA) has been included imaging findings (X-rays or magnetic resonance imaging) or associated clinical findings in addition to chronic back pain. New bone formation is the most important predictors of disease progression. Therefore it is the main target of disease management. Prevention of new bone formation might control an important cause of morbidity. X-rays are currently the standard method in evaluating the new bone formation. Sacroiliac joint graphs are recognized as key imaging in the diagnosis and classification, but its importance is limited in progression. Spinal X-rays are used in the follow-up of disease progression. Various radiographic scores, which are consisted of defined lesions, are used for progression. In this review, the imaging methods and scoring systems which are used to evaluate the disease course or progression of axSpA will be evaluated. In addition to the contribution of these methods used to follow up, the limitations also will be discussed.