Bone marrow edema of the femoral head and transient osteoporosis of the hip.

The current article of this issue aims at defining the generic term of bone marrow edema of the femoral head as seen at MR imaging. It must be kept in mind that this syndrome should be regarded, not as a specific diagnosis, but rather as a sign of an ongoing abnormal process that involves the femoral head and/or the hip joint. We aim at emphasizing the role of the radiologists in making a specific diagnosis, starting from a non-specific finding on T1-weighted images and by focusing on ancillary findings on T2-weighted SE or fat-saturated proton-density weighted MR images.