AXIAL SPONDYLOARTHRITIS

Spondylitis - Oedema at one of the four corners of vertebral bodies. Spondylitis anterior ( = Romanus lesion) or posterior

Spondylodisciitis - Oedema at cortical plate (Andersson lesion)

Apophysitis Any facet joint from C2 to S1 may be involved

Costovertebritis Any CV joints from Th1 to Th12, marrow oedema extending to pedicles. Also costotransversitis

Enthesitis of spinal ligaments Supraspinal ligament, interspinal ligaments, ligamenta flava

Syndesmophytes/ankylosis Bridging or fusion corner to corner


SACROILIITIS

Required: definite subchondral marrow oedema/osteitis
Suspicious: synovitis, capsulitis, or enthesitis without marrow oedema/osteitis. Sacroiliitis but not necessarily active

If there is one lesion, it should be present on at least two slices.
If there are multiple lesions, one slice may be enough.