Patent classifications
G01R33/4215
Supporting structure for a gradient coil assembly of a MRI
A gradient coil assembly (62) for use in a Magnetic Resonance Imaging (MRI) system includes primary coils (68), shield coils (72) and a supporting structure (10) arranged between the primary coils (68) and the shield coils (72). The supporting structure (10) includes at least a supporting element (12) including a first end face (14) and at least a first recess (24) with an opening (26) in the first end face (14). The first recess (24) extends in a longitudinal direction (18) of the supporting element (12) forming a tray for receiving a passive shim bar.
Adult head-sized coil-based low-field MRI
An ultra-low field pre-pulse Magnetic Resonance Imaging (PMRI) system for a head includes RF coils defining a bore for head access, a pre-pulse coil outside the RF coils, and a coil assembly including a main magnetic field coil and gradient coils outside the pre-pulse coil. The PMRI system includes a first cylindrical shield concentric with the RF coils and made from conductive materials. The first cylindrical shield partially encloses the RF coils and inside the pre-pulse coil for shielding the RF coils from environmental electromagnetic disturbances.
Superconducting magnet apparatus and method for magnetizing a superconductor bulk magnet by field cooling through a ferromagnetic shield
A superconductor magnet apparatus (2) includes a superconductor bulk magnet (9), a cryostat (7) and a ferromagnetic shielding body (11). The bulk magnet has a superconductor bore (10), an axis (z) of rotational symmetry, and a maximum outer diameter OD.sub.bm in a plane perpendicular to the z axis. The superconductor bore has a minimum cross-sectional area S.sub.bo in a plane perpendicular to the z axis. The cryostat has a room temperature bore (8), the bulk magnet is arranged within the cryostat and the room temperature bore is arranged within the superconductor bore. The shielding body has a shielding bore (12), the bulk magnet is arranged within the shielding bore and the shielding body extends beyond the bulk magnet at each axial end by at least OD.sub.bm/3. For an average cross-sectional area S.sub.fb of the shielding body, S.sub.fb≥2.5*S.sub.bo, and the shielding body is arranged within the cryostat.
Gradient coil
A gradient coil according to an embodiment is configured to generate gradient magnetic fields along a plurality of axes in an imaging space in which a subject is imaged. The gradient coil includes a coil corresponding to at least one of the plurality of axes, wherein an electrically-conductive member of the coil is formed so as to be partitioned in a thickness direction by a plurality of electrically-insulative layers.
GRADIENT COIL STRUCTURE FOR HEAT POWER REDUCTION
A gradient coil for an MRI apparatus is disclosed, comprising a main coil layer and a shielding coil layer. The shielding coil layer is arranged around the main coil layer, which includes an X, Y, and Z main coil set, and an X and Y end shielding coil set. The X end shielding coil set is connected in series with the X main coil set and used to form a shielding magnetic field in a direction opposite to the X direction. The Y end shielding coil set is connected in series with the Y main coil set and used to form a shielding magnetic field in the opposite direction to the Y direction. In the Z direction, the X end shielding coil set and Y end shielding coil set are disposed outside an imaging region enclosed by the main coil layer.
Magnetic resonance imaging device and superconducting magnet
Provided are a magnetic resonance imaging device and a superconducting magnet capable of preventing generation of eddy currents accompanying vibration of a radiation shield and of reducing image quality deterioration. The superconducting magnet for a magnetic resonance imaging device includes a substantially cylindrical vacuum vessel, a substantially cylindrical radiation shield that is provided inside the vacuum vessel, and a superconducting coil that is provided inside the radiation shield. The radiation shield has an inner cylinder located radially inward of the superconducting coil. The inner cylinder of the radiation shield is provided with an annular rib formed in a circumferential direction about the central axis of the inner cylinder.
Low-field magnetic resonance imaging methods and apparatus
According to some aspects, a low-field magnetic resonance imaging system is provided. The low-field magnetic resonance imaging system comprises a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, the magnetics system comprising, a B0 magnet, a plurality of gradient coils, and at least one radio frequency coil, a power system comprising one or more power components configured to provide power to the magnetics system to operate the magnetic resonance imaging system to perform image acquisition, and a power connection configured to connect to a single-phase outlet to receive mains electricity and deliver the mains electricity to the power system to provide power needed to operate the magnetic resonance imaging system.
SPLIT SELF-SHIELDED GRADIENT COIL SYSTEM, WITH POWER SUPPLY SYSTEM FOR INDIVIDUALLY ADJUSTING CURRENTS OF SUB-COIL GROUPS
A gradient coil system for use in a magnetic resonance device comprises a main coil having at least two main sub-coils for generating a gradient coil magnetic field in a target volume, a shielding coil having at least two shielding sub-coils for shielding the main coil, and a power supply system configured to adjust a plurality of electric currents. The main coil and the shielding coil are arranged coaxially along a z-axis, wherein the gradient coil magnetic field is aligned with the z-axis and varies along a gradient direction. The gradient coil system comprises N sub-coil groups, with N2, with each of the N sub-coil groups comprising a main sub-coil and a shielding sub-coil (3a-3d) connected in series. The power supply system is configured to adjust the electric current of each of the N sub-coil groups individually. The system provides strong gradient coil magnetic fields with improved switching time.
Gradient coil unit for a magnetic resonance apparatus
The invention relates to a gradient coil unit comprising a first conductor structure arranged on a surface of a first cylinder with the first radius, a second conductor structure arranged on a surface of a second cylinder with the second radius and a third conductor structure arranged on a surface of a third cylinder with the third radius, wherein the first radius is smaller than the second radius and the second radius is smaller than the third radius.
System and methods for grounding patients during magnetic resonance imaging
A magnetic resonance imaging (MRI) system, comprising a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, electromagnetic shielding provided to attenuate at least some electromagnetic noise in an operating environment of the MRI system, and an electrical conductor coupled to the electromagnetic shielding and configured to electrically couple to a patient during imaging of the patient by the MRI system. The magnetics system may include at least one permanent B.sub.0 magnet configured to produce a B.sub.0 magnetic field for an imaging region of the MRI system. The B.sub.0 magnetic field strength may be less than or equal to approximately 0.2 T.