Sacroiliitis is most commonly seen in axial spondyloarthritis(axSpA).Imaging plays a crucial role in the diagnosis and follow-up of sacroiliitis.Techniques such as MRI and CT can detect early inflammatory changes in the sacroiliac joints,aiding in the timely diagnosis of axSpA and the development of individualized treatment plans.However,sacroiliitis is not exclusive to axSpA,and its differential diagnosis requires consideration of multiple potential causes,including infectious,degenerative,traumatic,and other inflammatory conditions,which may present with similar imaging features.In addition,bone marrow edema of sacroiliac joints may be present in healthy people,athletes and postpartum women.In addition,,sacroiliac joint bone marrow edema can also occur in healthy individuals,athletes,and postpartum women.Therefore,accurate differentiation is essential to avoid misdiagnosis and missed diagnoses.