The term spondyloarthritis refers to a group of systemic conditions characterised by a range of clinical manifestations, laboratory and imaging features, with strong association to the HLA B27 gene [1]. The spectrum of spondyloarthritis includes ankylosing spondylitis, psoriatic arthritis, arthritis related to inflammatory bowel disease, reactive arthritis and undifferentiated arthritis.

Skeletal involvement may be axial, typically involving the sacroiliac joints and the spine, whilst peripheral involvement may include dactylitis, enthesitis, and oligo/monoarthritis. Typical extra- articular manifestations include uveitis, psoriasis and inflammatory bowel disease [2].

Diagnosis is mainly based on clinical history and examination, with imaging findings and blood tests aiding to confirm the diagnosis. Clinical diagnosis is guided by validated diagnostic criteria, such as the Amor and European spondyloarthropathy study group criteria for general spondyloarthropathy, with other criteria specific for axial or peripheral spondyloarthritis.

Current NICE guidelines suggest offering plain film assessment for axial spondyloarthritis in skeletally mature individuals, through which radiographic spondyloarthritis can be made if sacroilitis is diagnosed [3]. Subsequent imaging with MRI can be performed if plain film is not diagnostic. Plain film assessment can be offered for peripheral spondyloarthritis, with further imaging modalities in non diagnostic cases including ultrasound and MRI. CT is not routinely performed as part of the investigation for spondylitis, but may show imaging findings seen in both plain radiography and MRI imaging.