Electricity: measuring and testing – Particle precession resonance – Spectrometer components
Patent
1990-12-10
1992-07-21
Tokar, Michael J.
Electricity: measuring and testing
Particle precession resonance
Spectrometer components
335300, 335301, G01R 3320
Patent
active
051326183
ABSTRACT:
In a magnetic resonance imaging apparatus, there are provided: an MR (magnetic resonance) imaging unit having an imaging hole at a substantially central portion thereof, into which an object under medical examination is inserted; a superconducting coil unit stored within an outer vessel which is positioned around the imaging hole, and including a superconducting coil assembly for uniformly producing a static magnetic field to be applied to the object, and at least one heat shield tube or thermally shielding the superconducting coil assembly stored therein; a gradient field coil assembly provided between the outer vessel and imaging hole; for producing a gradient magnetic field so as to be superimposed with the static magnetic field. Further, it employs a active shield gradient coil assembly for producing a gradient shield field, and disposed within the outer vessel in such a manner that the active shield gradient coil assembly is thermally coupled to the heat shield tube and also magnetically coupled with a leakage field leaked from the gradient magnetic field of the gradient field coil assembly, whereby the leakage field is magnetically canceled by the gradient shield field and substantially no eddy current is produced in the heat shield tube.
REFERENCES:
patent: 4651117 (1987-03-01), Kawaguchi et al.
patent: 4733189 (1988-04-01), Punchard et al.
patent: 4737716 (1988-04-01), Roemer et al.
patent: 4771256 (1988-09-01), Laskaris et al.
patent: 4783628 (1988-11-01), Huson
patent: 4794338 (1988-12-01), Roemer et al.
patent: 4876510 (1989-10-01), Siebold et al.
patent: 4924185 (1990-05-01), Matsutani
patent: 4990878 (1991-02-01), Takechi et al.
P. Manfield & B. Champman, Jour. of Phys. E. Sc. Instru., vol. 19, 1986, "Active Magnetic Screening of Coils for Static and Time-Dependent Magnetic Field Generation in NMR Imaging", pp. 540-545.
R. Turner, et al., Jour. of Magnetic Resonance, vol. 80, No. 2, Nov. 1988, entitled "Snap-Shot Magnetic Resonance Imaging at 0.1 T Using Double-Screened Gradients" pp. 248-258.
B. Champman & P. Manfield, Jour. of Physics D. App. Phys., vol. 19, 1986, entitled "Double Active Magnetic Screening of Coils in NMR", pp. 129-131.
Kabushiki Kaisha Toshiba
Mah Raymond Y.
Tokar Michael J.
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