MRI—active lesions and structural changes (SC) of the axial skeleton
| Characteristics | AS (n=39) | nr-axSpA (n=36) | All patients (n=75) | p Value* |
|---|---|---|---|---|
| SIJ osteitis score (0–24), mean (SD) (NAP) | 7.6 (6.3) (n=36) | 5.7 (5.2) (n=34) | 6.7 (5.8) (n=70) | 0.2761† |
| SIJ fatty deposition score (0–8), mean (SD) (NAP) | 4.8 (3.2) (n=32) | 2.4 (2.7) (n=22) | 3.6 (3.2) (n=54) | 0.0013† |
| SIJ sclerosis score (0–2), mean (SD) (NAP) | 1.4 (0.9) (n=30) | 1.1 (0.8) (n=27) | 1.3 (0.8) (n=57) | 0.1328† |
| SIJ erosion score (0–6), mean (SD) (NAP) | 4.2 (2.3) (n=33) | 3.8 (1.8) (n=32) | 4.0 (2.1) (n=65) | 0.127† |
| SIJ ankylosis score (0–4), mean (SD) (NAP) | 0.7 (1.5) (n=8) | (0) | 0.4 (1.1) (n=8) | 0.0045† |
| Spine osteitis score (0–69), mean (SD) (NAP) | 2.6 (4.1) (n=21) | 1.1 (1.9) (n=14) | 1.9 (3.3) (n=35) | 0.1464† |
| Spine fatty deposition score (0–69), mean (SD) (NAP) | 2.2 (5.9) (n=13) | 1.3 (2.8) (n=10) | 1.8 (4.6) (n=23) | 0.6124† |
| Spine erosion score (0–46), mean (SD) (NAP) | 0.3 (0.7) (n=10) | 0.1 (0.4) (n=3) | 0.2 (0.6) (n=13) | 0.0516† |
| Spine bone proliferation score (0–69), mean (SD) (NAP) | 0.8 (2.5) (n=8) | 0.1 (0.3) (n=1) | 0.5 (1.9) (n=9) | 0.0193† |
| Spine posterior segments | ||||
| No of sites | 16 | 3 | 19 | 0.0385† |
| No of patients | 10 | 3 | 13 | |
*For the difference between ankylosing spondylitis and non-radiographic axial spondyloarthritis.
†Wilcoxon test.
AS, ankylosing spondylitis; NAP, number of affected patients; nr-axSpA, non-radiographic axial spondyloarthritis; SIJ, sacroiliac joints.