Chemical shift MR imaging using oscillating gradient fields-an approach by the short-time Fourier transform

Abstract

The author describes an approach to the problem of chemical-shift imaging using the short-time Fourier transform and the wavelet. When point sources of different chemical-shift values are measured with varying gradient field, these points travel along different loci in the instantaneous frequency vs. time diagram. Following the locus of a chemical-shift component of interest, the spatial distribution of the component can be observed with a varying degree of confidence. Taking an average over the profiles obtained at different gradient field intensities, the spatial profile solely due to a chemical-shift component can be reconstructed if each profile is scaled to the same bandwidth.<>