Systems, methods and apparatus of a magnetic resonance imaging magnet to produce an asymmetrical stray field
AssigneeGeneral Electric Company
InventorTimothy Havens
Life of this patent
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Abstract
Systems, methods and apparatus are provided through which in some embodiments a magnetic resonance imaging (MRI) system includes an asymmetrical magnet to generate an asymmetrical stray field that is particularly well suited to imaging limbs. In some other embodiments, a MRI system includes a conically-shaped casing that allows a patient to more readily access a field-of-view (FOV) in the interior of the MRI system during imaging of limbs. In some embodiments, a MRI system includes a stepped inner bore that has a stepped shape that focuses the FOV in an inner bore of the MRI system on a smaller area that is closer to where a patient accesses the FOV in the MRI that is particularly well suited to imaging a limb in the FOV.
Claims27
A magnetic resonance imaging apparatus to image a subject, the magnetic resonance imaging apparatus comprising:
- a casing having an inner bore;
- a plurality of magnetic main coils positioned in an asymmetrically-shaped array in the casing, in close proximity to the inner bore;
- and
- a plurality of magnetic shield coils positioned in an asymmetrically-shaped array in the casing, radially outward of the main coils,
- wherein the magnetic shield coils further comprises reduced magnetic shield coils at one end.
An apparatus to image a subject, the apparatus comprising:
- a casing having a conically-shaped outer perimeter, the casing having an inner bore;
- and
- a plurality of magnetic main coils positioned in the casing in close proximity to the inner bore.
An apparatus to image a subject using magnetic resonance, the apparatus comprising:
- a casing having an inner bore, the inner bore defining an inner diameter of the casing, wherein the inner diameter of the inner bore further comprises a stepped radius;
- and
- a plurality of magnetic coils positioned in the casing in close proximity to the stepped inner radius,
- wherein the stepped radius of the inner diameter of the inner bore further comprises:
- a first portion of the inner bore having a first radius, wherein a gradient coil is attached to the first portion;
- and
- a second portion of the inner bore having a second radius that is less than the first radius.
A computer-accessible medium having executable instructions capable of directing a processor to perform:
- driving a gradient coil to spatially encode the magnetic resonance image;
- driving a gradient eddy current correction coil in a magnetic resonance imaging system to correct for asymmetric eddy currents generated by the gradient coil in the asymmetric magnet;
- and
- receiving radio frequency signals of gradient encoded images including correction by the gradient eddy current correction coil.
A method comprising:
- driving a gradient coil in a magnetic resonance imaging system to spatially encode a magnetic resonance image;
- driving a gradient eddy current correction coil in the magnetic resonance imaging system to correct for asymmetric eddy currents generated by the gradient coil in the asymmetric magnet;
- and
- generating an image from the radio frequency signals of gradient encoded images.
A computer-accessible medium in a magnetic resonance imaging system, the medium comprising:
- a driver of a gradient coil for spatially encoding a magnetic resonance image;
- a driver of a gradient eddy current correction coil in a magnetic resonance imaging system;
- and
- a receiver of radio frequency signals representing gradient encoded image signals including correction by the gradient eddy current correction coil.
Dependencies are inferred from the claim text.