Electricity: measuring and testing – Particle precession resonance – Using a nuclear resonance spectrometer system
Patent
1993-10-26
1995-10-03
O'Shea, Sandra L.
Electricity: measuring and testing
Particle precession resonance
Using a nuclear resonance spectrometer system
G01R 3348
Patent
active
054555124
ABSTRACT:
In an MRI device operating according to a spin-echo method, switched gradient magnetic fields are applied in the form of slice selection, phase encoding and read gradients. The switching of the gradients causes eddy currents in metal parts of the apparatus. The eddy currents disturb the applied magnetic fields, thereby changing the phases of the precessing nuclear spins of a body to be examined and causing artefacts in a reconstructed image. The disturbing effects of the eddy currents is compensated for by supplementing a sequence of switched gradient magnetic fields with additional gradient fields. These additional fields have zero net effect but induce further eddy currents which compensate for the disturbing effects of the eddy currents generated by the regular switched gradient magnetic fields. The additional gradient fields are chosen such that the total time-integrated strength of a gradient in any interval between two RF-pulses is substantially equal to the desired value.
REFERENCES:
patent: 4647858 (1987-03-01), Bottomley
patent: 4698591 (1987-10-01), Glover et al.
patent: 4823084 (1989-04-01), McKinnon
patent: 4896112 (1990-01-01), Ratzel et al.
patent: 4924186 (1990-05-01), Kawamoto et al.
Groen Johannes P.
Mehlkopf Antoon F.
van der Meulen Peter
Van Yperen Gerrit H.
Mah Raymond Y.
O'Shea Sandra L.
Slobod Jack D.
U.S. Philips Corporation
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