Seven S, Ostergaard M, Morsel-Carlsen L, et al. - This study was undertaken to investigate sacroiliac joint (SIJ) MRI inflammation, structural and degenerative lesion characteristics in patients with axial spondyloarthritis(axSpA) and various control groups. In this study, individuals with axSpA(n = 41) and lumbar disc herniation(n = 25), women with(n = 46) and without(n = 14) post-partum(childbirth within 4–16 months) buttock/pelvic pain, cleaning assistants(n = 26), long-distance runners(n = 23) and healthy men(n = 29) had MRI of the SIJs prospectively conducted. According to the findings, FAT depth > 5mm, but not bone marrow oedema (BME) depth > 10mm, could almost differentiate axSpA patients from all other groups. It was shown that BME > 5mm and erosion were highly specific for axSpA when excluding post-partum women.