The hip was one of the first joints to be widely studied with magnetic resonance imaging (MRI), probably because of its large size and because surface coils necessary to study smaller joints were not widely available. Because the hip was included within the field of view when soft tissue organs of the pelvis were evaluated, numerous images of normal hips were available for study, and the normal anatomy was quickly described. Early clinical studies centered on the changes produced by femoral head ischemic necrosis. Other abnormalities of the hip also have been described, including arthritis, transient edema, marrow-packing disorders, infection, and fractures.