title: Correction of phase effects produced by eddy currents in solvent suppressed 1H-CSI.
abstract: Accurate phasing of MRS spectra is often difficult unless time varying phase effects produced by gradient-induced eddy currents that persist during data acquisition are eliminated. This effect is particularly problematic in 1H-CSI spectra where frequency shifts produced by static field inhomogeneity and phase shifts produced by eddy currents combine. In this paper we present a method that corrects both shifts and eliminates manual phasing of individual CSI spectra typically required to recover a pure absorption line shape. The method uses a time domain phase correction derived from the ambient water signal acquired under identical conditions (i.e., acquisition parameters, gradient sequence) as the solvent-suppressed CSI data. Results from CSI experiments on phantoms and in vivo solvent suppressed 1H-CSI spectra from normal human brain are presented demonstrating the capabilities of the technique.
authors.affiliation: Bioengineering Program, University of Michigan, Ann Arbor.
authors.forename: J R
authors.initials: JR
authors.lastname: Roebuck
authors.forename: D O
authors.initials: DO
authors.lastname: Hearshen
authors.forename: M
authors.initials: M
authors.lastname: O'Donnell
authors.forename: T
authors.initials: T
authors.lastname: Raidy
mesh_terms: D000465:Algorithms; D001921:Brain / Q000378:metabolism; D005583:Fourier Analysis; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008961:Models, Structural; D012815:Signal Processing, Computer-Assisted