Magnetic resonance spectroscopic and relaxometric determination of bone marrow changes in anorexia nervosa

Objective: The objective of this study was to assess and quantify bone marr ow changes in patients with anorexia nervosa using H-1 magnetic resonance s pectroscopy and relaxometry. Methods: The bone marrow fat fraction and the longitudinal and transverse relaxation times (T1 and T2, respectively) of w ater were measured in the lumbar and femoral marrow of 20 patients with ano rexia nervosa and 19 healthy control subjects. Results: Patients with anore xia nervosa showed significant hyperhydration and reduction of the fat frac tion in their bone marrow, predominantly in the proximal femur. These chang es were associated with hematological abnormalities. In a retest of seven p atients after psychotherapy and gain of weight, the pathological changes in marrow proved to be largely reversible in correlation with the increase in body mass index, Conclusions: Fat depletion and excess of tissue water in the bone marrow in anorexia nervosa can be quantified by H-1 magnetic reson ance spectroscopy and relaxometry. The distribution of the pathological cha nges in the lumbar and femoral marrow follows the pattern of normal bone ma rrow conversion from hematopoietic to cellular during childhood.