NMR imaging method
AssigneeHitachi, Ltd.
InventorsKensuke Sekihara, Shigeru Matsui, Hideki Kohno
Life of this patent
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Abstract
In imaging methods represented by the echo-planar method, i.e., in a method including a step of measuring the spin echos while applying a fixed gradient magnetic field to an object and applying a gradient field G.sub.Y periodically inverted in sense to the object and a step of obtaining the spin distribution image in the spatial domain by applying two-dimensional Fourier transform to the measured data, measurement is repeated a plurality of times while altering the phase of the applied waveform of G.sub.X, and the spin density image is derived by applying two-dimensional Fourier transform to a plurality of sets of data groups thus obtained.
Claims8
An NMR imaging method for obtaining a spin distribution image of a certain region of an object placed in a static magnetic field, including steps of;
- (a) exciting nuclear spins in said region of said object,
- (b) inverting the sense of said nuclear spins by a 180.degree. RF pulse in order to generate a spin echo,
- (c) applying a first fixed gradient magnetic field along a first direction and a second gradient magnetic field periodically inverted in sense in a second direction perpendicular to the first direction to said object in order to generate a train of spin echoes,
- (d) sampling spins signals of said train of spin echoes in order to obtain a data group,
- (e) repeating the steps of (a)-(d) in order to obtain a plurality of data groups with the phase of the wave form of said second gradient magnetic field remaining constant in each repetition and said phase being altered in the successive repetitions, and
- (f) reconstructing the spin distribution image by applying two-dimensional Fourier transform to said plurality of data groups.
Dependencies are inferred from the claim text.