This document discusses imaging of the sacroiliac joint, including radiography and MRI findings. It begins with an overview of sacroiliac joint anatomy. It then describes common radiographic views and classifications of sacroiliac joint damage. The document focuses on using MRI to identify inflammatory lesions in the sacroiliac joints that can indicate early spondyloarthritis. It discusses how stopping NSAIDs before MRI may have little impact on findings. Repeating sacroiliac MRI months later generally does not reveal new cases, except possibly in HLA-B27 positive men. The document recommends sacroiliac MRI over spine MRI alone for axial spondyloarthritis workup given the low yield of isolated spinal findings without sac