An MR arthrogram is a diagnostic test designed to make detailed pictures of the cartilage, ligaments, and supporting structures of joints. These structures are not as well depicted on routine MRI exams. The radiologist will clean the skin overlying the joint, freeze the skin with local anesthetic, and (while watching with the X-ray machine) place a very small needle into the joint space. A mixture of X-ray dye and MRI dye will be slowly injected into the joint. The dye outlines the structures within the joint. An MRI examination will then be performed.

This is not a painful test. If the injection or needle placement is hurting, the radiologist will give more anesthetic. The joint may be a bit sore for 24 hours after the procedure but it will respond well to over-the-counter anti-inflammatory agents like ibuprofen.