Proton magnetic resonance spectroscopy for assessment of human body composition

Background: The usefulness of magnetic resonance spectroscopy (MRS)-based t echniques for assessment of human body composition has not been established . Objective: We compared a proton MRS-based technique with the total body wat er (TBW) method to determine the usefulness of the former technique for ass essment of human body composition. Design: Proton magnetic resonance spectra of the chest to abdomen, abdomen to pelvis, and pelvis to thigh regions were obtained from 16 volunteers by using single, free induction decay measurement with a clinical magnetic res onance system operating at 1.5 T. The MRS-derived metabolite ratio was dete rmined as the ratio of fat methyl and methylene proton resonance to water p roton resonance. The peak areas for the chest to abdomen and the pelvis to thigh regions were normalized to an external reference (approximate to 2200 g benzene) and a weighted average of the MRS-derived metabolite ratios for the 2 positions was calculated. TBW for each subject was determined by the deuterium oxide dilution technique. Results: The MRS-derived metabolite ratios were significantly correlated wi th the ratio of body fat to lean body mass estimated by TBW. The MRS-derive d metabolite ratio for the abdomen to pelvis region correlated best with th e ratio of body fat to lean body mass on simple regression analyses (r = 0. 918). The MRS- derived metabolite ratio for the abdomen to pelvis region an d that for the pelvis to thigh region were selected for a multivariate regr ession model (R = 0.947, adjusted R-2 = 0.881). Conclusion: This MRS-based technique is sufficiently accurate for assessmen t of human body composition.