Increase Sensitivity for BME, Erosions for Patients Undergoing MRI for axSpA

Background: Imaging is a crucial component in the diagnosis and management of axial spondyloarthropathy (axSpA), as these conditions can be challenging to diagnose solely based on clinical findings. Objective: To review current updates on imaging of axSpA, with emphasis on the anatomy of the sacroiliac joint (SIJ) and optimization of MRI protocols to reduce diagnostic pitfalls and technical errors. Discussion: The authors emphasize that the anatomy of the SIJ more closely resembles a symphysis, rather than a true synovial joint along its proximal two-thirds. Terms like "capsulitis" and "joint space inflammation" are more appropriate terms for characterization of inflammatory findings compared to terms, such as "synovitis" as true synovitis is often absent. One diagnostic pitfall to keep in mind is that anatomic variations of the SIJs exist and can mimic pathologic bone marrow edema (BME), which is a common sign of axSpA. The authors also emphasize that BME detection is highly depende more...