Electricity: measuring and testing – Particle precession resonance – Spectrometer components
Patent
1988-08-17
1990-02-06
Tokar, Michael J.
Electricity: measuring and testing
Particle precession resonance
Spectrometer components
324319, G01R 3320
Patent
active
048991090
ABSTRACT:
An automated magnetic field shimming process for magnetic resonance spectroscopic imaging (MRSI) uses doubly phase encoded NMR spin echo responses in conjunction with multiple fourier transformation to derive a spectroscopic plot for each voxel in a three-dimensional array of voxels in an image volume (including portions of a living subject) which is to be subsequently subjected to MRSI using NMR FID or spin echo responses. The thus derived hydrogen peak frequency is taken as a measurement of existing static magnetic field intensity within that voxel and adjusted shim coil currents are calculated so as to reduce or minimize nonuniformity of the static magnetic field. A nonexistent pseudo shim coil having an assumed uniform shim contribution may enhance the resulting field homogeneity. The auto shimming procedure may be applied iteratively as required to achieve the predetermined degree of field uniformity.
REFERENCES:
patent: 4680551 (1987-07-01), O'Donnell et al.
patent: 4682112 (1987-07-01), Beer
patent: 4720679 (1988-01-01), Patrick et al.
patent: 4740753 (1988-04-01), Glover et al.
patent: 4761614 (1988-08-01), Prammer et al.
MacKenzie et al, "A Simple Field Map for Shimming", Mag. Reson. in Med., vol. 5, 1987, pp. 262-268.
Doddrell et al, "Nodal Inhomogeneity Mapping by Localized Excitation--the , `NIMBLE` Shimming Technique for High-Resolution in vivo NMR Spectroscopy", Mag. Reson. in Med., vol. 7, 1988, pp. 352-357.
Prammer et al-Journal of Magnetic Resonance 77, 40-52 (1988), "A New Approach to Automatic Shimming".
Maudsley et al-J. Phys, E: Sci.Instrum., vol. 17, 1984, "Magnetic Field Measurement by NMR Imaging"-5 pages.
Maudsley et al-Magnetic Resonance In Medicine 2, 218-233 (1985), "Filed Inhomogeneity Correction and Data Processing for Spectroscopic Imaging".
Derby Kevin A.
Hawryszko K. Christine
Tropp James S.
Diasonics Inc.
Tokar Michael J.
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