[Imaging diagnosis in femur head necrosis with emphasis on skeletal scintigraphy and magnetic resonance tomography].

Early diagnosis and treatment of avascular necrosis (AVN) of the femoral heads improve the prognosis of this disorder. Of the different radiological studies available so far, none has been truly satisfactory. Conventional X-rays frequently show alterations in the femoral heads only in later stages. Early on these may be so subtle that they are overlooked by the examiner. Bone scintigraphy is more sensitive than conventional X-rays in the detection of early alterations, but there are still up to 18% negative studies in biopsy-proven femoral-head necrosis. The sensitivity of this method is also diminished when bilateral AVN is present. This is frequently the case even if only one hip joint is symptomatic. Computed tomography (CT) and single photon emission computed tomography (SPECT) are highly sensitive methods that are still not widely used for the diagnosis of AVN. With SPECT, clinical experience is still limited. A number of publications in recent years have revealed the excellent characteristics of magnetic resonance imaging (MRI) in showing the pathological processes in bone marrow and, in particular, AVN. This paper summarizes a few of these publications and our personal experience with MRI in AVN of the femoral head. Different cases examples are given.