Some bone alterations seem to be linked to medullary adiposity that could play a major role in the physiopathology of several disorders involving bone marrow. Although the mechanisms intervening between osteogenesis and adipogenesis are not completely understood, they could be responsible for modifications of bone marrow composition. Some recent studies have demonstrated that yellow bone marrow represents a specific fat tissue, different from white or brown adipose tissues.Moreover these studies suggested that yellow bone marrow could have a significant role in the pathogenesis of several bone marrow diseases, especially involving the hip.MRI spectroscopy permits a quantitative non-invasive evaluation of the fat content of bone marrow, completing the diagnostic findings obtained with traditional IRM examination. 3 T MRI enables an improvement of spectra quality with relatively short acquisition time and it is adequate to clinical practice.The value of this technique has been poorly evaluated at the hip and no reproducibility studies or no normal values have been determined or published so far.The goal of the present research was to assess the role of 1H MR spectroscopy in the quantitative evaluation of hip bone marrow.This aim of this research project was threefold.The first axis of research was oriented to set the spectroscopic technique and to evaluate its reproducibility in the evaluation of hip bone marrow using a 3 T magnet. To the best of our knowledge this had not been assessed earlier. We demonstrated that 1H 3 T MRI spectroscopy is a reliable technique that permits to obtain highly reproducible fat content values of the hip bone marrow. Moreover we proved that no statistical significant difference existed when comparing left and right fat content values in the same individual. The results of this work have been accepted for publication.On this basis we obtained, within the second axis of this research project, normal hip fat content values in healthy subjects taking into account the age and the gender. This study enables to dispose of normal reference values in order to assess pathological conditions of hip bone marrow.The third axis of this project is on going. It concerns the research and the identification of possible abnormal spectra of hip bone marrow in patients affected from femoral head osteonecrosis or anorexia nervosa. At this time point, the recruitment of patients with osteonecrosis is over and we dispose of some preliminary results. The recruitment of patients affected from anorexia nervosa is currently in course.
