A PHASE-INSENSITIVE SINGLE-SCAN METHOD FOR VOLUME-SELECTIVE EDITING OF NMR SIGNALS USING CYCLIC POLARIZATION TRANSFER - INVIVO DETERMINATION OF LACTATE

A phase-insensitive pulse sequence serving the volume-selective editing of resonances in biomedical NMR spectroscopy is described. The editing principle is the temporary transfer of polarization of the spins to be detected to other species coupled to them. The technique is of particular interest for the localized detection of the lactate methyl proton line while spoiling coherences of uncoupled as well as coupled lipid nuclei otherwise overlapping the lactate resonance. The whole line-editing and coherence-spoiling procedure takes place completely in each scan of any accumulation or phase-cycling series. Phantom studies were carried out with an experimental 4.7 T system. The technique was also tested with volunteers in whole-body tomographs operating at 2 and 3 T. Comparative spectra are presented. It is concluded that editing is crucial for the reliable determination of lactate in muscle and in brain. © 1990.