Abstract
Conventional x-ray of sacroiliac (SI) joints is the major imaging technique for diagnostic purposes. However, this examination can only visualize changes in long duration of inflammatory process and the use in early stages of the disease is very limited.
In patients with short period from the first symptoms or patients with negative x-ray of SI joints and remaining suspicion of disease presence magnetic resonance imaging (MRI) can be used to capture early active changes in a form of bone marrow edema. Both these methods form the imaging arm of ASAS (Assessment of SpondyloArthritis International Society classification) criteria for axSpA.
In evaluation of disease progression spine x-rays are widely used in clinical practice. Several scoring methods are available from which modified Stokes Ankylosing Spondylitis Spinal Score (mSASSS) is the most common.
General recommendation is not to repeat spine x-rays earlier then in two years interval because of slow disease progression. Other imaging techniques have only limited value for diagnostic purposes or estimation of disease progression.