METHOD OF LOCALIZING NMR CHEMICAL SHIFT INFORMATION BY DEPTH-RESOLVED COIL SPECTROSCOPY

摘要

A method for obtaining spatially resolved nuclear magnetic resonance chemical shift spectra, by depth-resolved surface coil spectroscopy (DRESS), substantially eliminates surface tissue contamination of the chemical shift spectra by employing selective excitation in the presence of a gradient magnetic field directed coaxial with the axis of a surface coil. The nuclei in a disk-shaped preselected volume are excited by a selective radio-frequency signal pulse applied in the presence of the gradient field. The surface coil is always utilized for receiving magnetic resonance response signals, while the same surface coil, or a separate transmitting antenna, can be used to provide the radio-frequency excitation field across the selected disk-shaped volume. The technique can be combined with conventional 90 DEG - tau -180 DEG or 180 DEG - tau -90 DEG relaxation time measurement RF pulse sequences, or with a solvent suppression NMR spectroscopy technique employing selective excitation.