Nodal inhomogeneity mapping by localized excitation--the "NIMBLE" shimming technique for high-resolution in vivo NMR spectroscopy.
A method (NIMBLE) for obtaining optimum B0 field homogeneity at voxels located away from the magnet isocenter for use in volume-selected NMR spectroscopy is described. Voxels may be shimmed using only first-order X, Y, and Z shims to produce three-dimensional shim current maps, thus avoiding shim coupling problems. NIMBLE shimming prior to volume selection ensures optimum spectral resolution and improves the efficiency and accuracy of the volume-selection experiment. The benefits of the technique are illustrated by a high-resolution volume-selected spectrum of human tibia marrow.
Doddrell
D M
DM
Department of Chemistry, University of Queensland, St. Lucia, Australia.
Galloway
G J
GJ
Brereton
I M
IM
Brooks
W M
WM
D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008433:Mathematics; D008953:Models, Anatomic