Table 1.

Patient characteristics

	All patients	Patients with inflammatory disease (n=40)	Patients with non-inflammatory disease (n=28)
Sex	41.2% female (28/68)	27.5% female (11/40)	60.71% female (17/28)
Age	40.54±12.23	39.85 (SD 12.23)	41.54 (SD 11.96)
HLA-B27 positivity	55.8% (29/52)	73.33% (22/30)	21.82% (7/22)
Mean CRP	12.34 (n=24)	14.89 (SD 17.78; n=15)	7.58 (SD 18.38; n=9)+negative in 3 patients
BASDAI	4.67±1.61 (n=33)	4.6 (SD 1.61; n=27)	5.02 (SD 1.61; n=6)
Modified New York Criteria positivity	N/A	52.5% (21/40)	N/A
ASAS MRI criteria positivity	N/A	52.5% (21/40)	N/A
Erosion sum score	2.05 (SD 3.37)	3.16 (SD 3.37)	0.46 (SD 3.29)
Sclerosis sum score	2.87 (SD 3.09)	3.26 (SD 3.09)	2.31 (SD 3.03)
Joint space sum score	2.26 (SD 3.26)	3.53 (SD 3.26)	0.45 (SD 3.24)

Patient characteristics are presented for all patients and by subgroup according to the rheumatologist’s final diagnosis (inflammatory vs non-inflammatory disease) by the rheumatologist. Inflammatory conditions were axial spondyloarthritis (axSpA) (n=35; r-axSpA: n=29, nr-axSpA: n=6), psoriatic arthritis with axial inflammation (n=4) and SAPHO (n=1). Non-inflammatory conditions were degenerative spine disease (n=14), osteitis condensans ilii (n=13) and psoriatic arthritis without axial involvement (n=1). The sum scores are mean scores in CT.

ASAS, Assessment of SpondyloArthritis international Society; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; CRP, C-reactive protein; SAPHO, synovitis, acne, pustulosis, hyperostosis and synovitis syndrome.