Techniques for corrected nuclear magnetic resonance (NMR) data include applying a presaturation radio frequency (RF) magnetic field different from a fat molecule resonance for a particular time to a target tissue; and applying a first measurement RF magnetic field within a first time after the particular time. Correction nuclear magnetic resonance (NMR) data from the target tissue is determined based on first NMR data received in response to applying the first measurement RF magnetic field. In some embodiments, a second measurement RF magnetic field is also applied in a second time different from both the particular time and the first time. Corrected NMR data is determined by subtracting the correction NMR data from second NMR data received in response to applying the second measurement RF magnetic field. Among other applications, these techniques allow distinguishing either fat or proteins in edemas, or both, from proteins in other tissues.