Electricity: measuring and testing – Particle precession resonance – Using a nuclear resonance spectrometer system
Reexamination Certificate
2007-11-06
2007-11-06
Arana, Louis M. (Department: 2859)
Electricity: measuring and testing
Particle precession resonance
Using a nuclear resonance spectrometer system
C324S307000
Reexamination Certificate
active
11199660
ABSTRACT:
A magnetic resonance (NMR) method for fast, dynamic, spatially resolved measurement of the temporal changes in NMR signals by means of repeated data acquisition in individual measurements (Acq) with measuring sequences which are sensitive to a parameter to be observed, in an NMR apparatus with shim coils for correcting the magnetic field is characterized in that during data acquisition of each individual measurement (Acq) in acquisition steps (S1 . . .Sn) with a time lag, the magnetic field distribution in the NMR apparatus is measured, technically or physiologically based changes in the magnetic field distribution are determined therefrom in a calculation step (Scalc) as well as a change in the currents in the magnetic field required for compensation thereof, and the dynamic changes in the magnetic field distribution are compensated for by means of the correspondingly changed shim currents. The inventive method permits dynamic detection of the changes in the magnetic field distribution through the above-mentioned factors during the measurement and compensation thereof through corresponding re-calculation of Δy(x,y,z) or ΔB0(x,y,z) and adjustment of the shim currents to render the magnetic field distribution for subsequent measurements again preferably identical to the initial magnetic field distribution.
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Hennig Juergen
Speck Oliver
Zaitse Maxim
Arana Louis M.
Hackler Walter A.
Universitätsklinikum Freiburg
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