NMR Spectroscopic Imaging Method for Static Magnetic Field Mapping

A previously published nuclear magnetic resonance (NMR) spectroscopic imaging method for mapping static magnetic fields has been modified, replacing the gradient echo sequence with an asymmetric spin echo sequence. The purpose of the modification is to reinforce the technique and make it useable even in conditions in which the gradient echo sequence cannot be operated. The modification performed was verified by an experiment performed on a low-field NMR scanner. The rough and fine errors due to the long time of measurement were corrected during the processing of the measured images. An optimization procedure was used to correct the fine errors. The map of the static magnetic field acquired using the new technique was compared to the map calculated from the phase images and both were compared to the result measured using a magnetometer. The verification confirmed the legitimacy of the modification and suitability of the novel technique. Some alternatives to the measured data processing have been suggested, shortening the global time of the measurement.