MRI of the pelvis: A guide to incidental findings for musculoskeletal radiologists

Patients undergoing magnetic resonance imaging (MRI) of the pelvis for presumed musculoskeletal disease are commonly found to have abnormal imaging findings in the incidentally imaged pelvic viscera. Such incidental findings can be problematic for the musculoskeletal imager, both in terms of assigning clinical significance and determining the appropriate workup for a given abnormality. In this article we discuss the normal MRI appearance of the various pelvic organ systems as well as normal variants, emphasizing those that can mimic pathological processes. We then discuss the MRI appearance of common pathological entities encountered in these organ systems and the key imaging findings that should warrant a recommendation for further radiologic and/or clinical evaluation.