Table 1

MRI findings in patients diagnosed with axial spondyloarthritis

Patient number	Active changes	Chronic changes	Meets ASAS definition of positive SIJ MRI ?
1 43, male B27 positive	Single area of SIJ BMO	Fatty changes around SIJs	Yes
2 58, male B27 negative	Multiple inflammatory vertebral corner lesions, but no SIJ BMO	No	No
3 67, male B27 negative	Bilateral SIJ BMO	Partial SIJ ankylosis	Yes
4 40, female B27 negative	Bilateral SIJ BMO	SIJ erosions	Yes
5 60, female B27 positive	Bilateral SIJ BMO	SIJ erosions	Yes
6 69, male B27 negative	Right SIJ BMO and BMO of multiple thoracic costovertebral joints	Fused left SIJ, sclerosis of multiple thoracic costovertebral joints	Yes
7 31, female B27 negative	Single non-specific area of BMO around left SIJ	None	No
8 34, female B27 negative	Left SIJ BMO	Erosion of right SIJ, multiple vertebral fatty corner lesions in thoracic spine	Yes
9 58, male B27 positive	Left SIJ BMO	Ankylosis right SIJ, erosions left SIJ	Yes
10 57, male B27 negative	Non-specific SIJ BMO; multiple inflammatory vertebral corner lesions	None	No
11 50, female B27 positive	None	Multiple vertebral fatty corner lesions	No
12 31, male B27 negative	Bilateral SIJ BMO	None	Yes
13 42, male B27 positive	Left SIJ BMO	Vertebral fatty corner lesions T7–T12	Yes
14 49, female B27 positive	Bilateral SIJ BMO and two inflammatory vertebral corner lesions in thoracolumbar spine	Fatty change both SIJs	Yes
15 58, female B27 positive	Bilateral SIJ BMO	Bilateral SIJ erosions	Yes
16 39, female B27 positive	Bilateral SIJ BMO	Partial fusion both SIJ inferiorly	Yes
17 45, female B27 positive	Multiple inflammatory vertebral corner lesions	Sclerotic right SIJ	No

ASAS, Assessment of Spondyloarthritis International Society; BMO, bone marrow oedema; SIJ, sacroiliac joint