[MRI in aseptic osteonecroses of the femoral head. Review of the literature].

Nuclear magnetic resonance has shed new light on our understanding of osteonecrosis of the femoral head. It is at present the most sensitive and most specific imaging technique for the diagnosis of this condition. Studies involving correlations between MR images and anatomical findings have facilitated the understanding of tissue changes responsible for magnetic appearances. However, all problems are not resolved. At an early stage, fortunately almost always asymptomatic, false negative MRI or MR findings similar to those of algoneurodystrophy of the hip can be encountered. The aim of this article is to pinpoint the current status of these questions on the basis of a review of the recent literature. The contribution of MRI with injection of Gadolinium and future prospects are also discussed.