Page 70 - Recognizing axial spondyloarthritis - Janneke de Winter

CHAPTER FOUR
(in 53 (82.8%) of 64 MRIs). In negative MRIs, BME was found most frequently in the anterior lower ilium (in 18 (16.7%) of 108 MRIs). Overall, BME was most frequently found in the posterior lower ilium (in 69 (40.1%) of 172 MÀRIs), and least frequently found in the anterior lower sacrum (in 40 (23.3%) of 172 MRIs).
Table 2. Anatomic distribution of bone marrow edema in the SI joint quadrants on MRI
Upper ilium Lower ilium Anterior Postrior Anterior Postrior
Upper sacrum Lower sacrum Anterior Postrior Anterior Postrior
Positive MRI of the SI joints (n = 64)
Negative MRI of the SI joints (n = 108)
Healthy participants (n = 47)
Patients with axial SpA
(n = 47)
Controls with chronic back pain (n = 47)
Runners (n = 24)
Women with post-partum back pain
(n = 7)
44 (68.8)
4 (3.7) 2 (4.3)
39 (83.0)
2 (4.3)
4 (16.7) 1 (14.3)
34 (53.1)
7 (6.5) 2 (4.3)
34 (72.3)
4 (8.5)
1 (4.2) 0 (0)
48 (75.0)
18 (16.7)
10 (21.3)
41 (87.2)
11 (23.4)
1 (4.2) 3 (43.0)
53 (82.8)
16 (14.8)
18 (38.3)
41 (87.2)
5 (10.6)
2 (8.3) 3 (43.0)
39 (60.9)
5 (4.6) 4 (8.5)
33 (70.2)
3 (6.4)
2 (8.3) 2 (28.6)
37 (57.8)
7 (6.5) 2 (4.3)
36 (76.6)
3 (6.4)
1 (4.2) 2 (28.6)
37 (57.8)
3 (2.8) 3 (6.4)
33 (70.2)
1 (2.1)
1 (4.2) 2 (28.6)
43 (67.2)
4 (3.7) 6 (12.8)
35 (74.5)
2 (4.3)
2 (8.3) 2 (28.6)
* Magnetic resonance images (MRIs) that indicated sacroiliitis according to the Assessment of SpondyloArthritis international Society (ASAS) definition were considered positive. Those that did not meet the ASAS definition were considered negative. Values are the number (%). SI = sacroiliac; SpA = spondyloarthritis.
DISCUSSION
The results of our study suggest that 1) one-fourth of asymptomatic healthy individuals and more than half of women presenting with postpartum back pain who do not have axial SpA may have an MRI positive for sacroiliitis according to the ASAS definition, meaning that their MRI lesions are considered highly suggestive of axial SpA by trained readers, 2) frequent runners do not seem to have more lesions than healthy asymptomatic individuals, 3) high SPARCC scores (≥5) rarely occur in healthy individuals, patients with chronic back pain without
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