(HealthDay)—Magnetic resonance imaging (MRI) positive for sacroiliitis is seen in a considerable number of healthy individuals without back pain, according to a study recently published in Arthritis & Rheumatology.
Janneke de Winter, M.D., from the University of Amsterdam, and colleagues compared MRI of the sacroiliac joints of 172 subjects: 47 healthy individuals without current or past back pain, 47 axial spondyloarthritis (SpA) patients, 47 controls with chronic back pain, seven women with postpartum back pain, and 24 frequent runners. The Assessment of SpondyloArthritis international Society (ASAS) definition and Spondyloarthritis Research Consortium of Canada (SPARCC) index were used to score MRIs.
The researchers found that 23.4 percent of the healthy volunteers had an MRI positive for sacroiliitis, compared with 91.5, 6.4, 12.5, and 57.1 percent of axial SpA patients, patients with chronic back pain, runners, and women with postpartum back pain, respectively. The corresponding proportions were 25.5, 97.9, 10.6, 16.7, and 57.1 percent using a SPARCC cutoff of ≥2 for positivity. Healthy volunteers, patients with chronic back pain, and runners did not have deep bone marrow edema lesions, but 89.4 percent of axial SpA patients and 14.3 percent of women with postpartum back pain did have lesions.
"A substantial proportion of healthy individuals without current or past back pain has an MRI positive for sacroiliitis according to the ASAS definition," the authors write. "Deep (extensive) bone marrow edema lesions are almost exclusively found in axial SpA patients."
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