Patent classifications
G01R33/421
SUPERCONDUCTING MAGNET
A superconducting magnet may include magnet coils including at least one group of outer coils and at least one group of inner coils, a container including an accommodating space, at least one first chamber that is disposed within the accommodating space and houses the at least one group of the inner coils, and at least one second chamber that is disposed within the accommodating space and houses the at least one group of the outer coils. The at least one first chamber and the at least one second chamber may be configured to be filled with a cooling medium and are in fluid communication with each other. The cooling medium may be configured to cool the magnet coils to a superconducting state.
Reducing magnetic field instabilities caused by oscillations of a mechanical cryo-cooler in magnetic resonance systems
Described here are systems and methods for mitigating or otherwise removing the effects of short-term magnetic field instabilities caused by oscillations of the cold head in a cryogen-free magnet system used for magnetic resonance systems, such as magnetic resonance imaging (“MRI”) systems, nuclear magnetic resonance (“NMR”) systems, or the like.
Reducing magnetic field instabilities caused by oscillations of a mechanical cryo-cooler in magnetic resonance systems
Described here are systems and methods for mitigating or otherwise removing the effects of short-term magnetic field instabilities caused by oscillations of the cold head in a cryogen-free magnet system used for magnetic resonance systems, such as magnetic resonance imaging (“MRI”) systems, nuclear magnetic resonance (“NMR”) systems, or the like.
Electric circuit arrangement for energizing a magnet of a magnetic resonance imaging facility and magnetic resonance imaging facility
An electric circuit arrangement for energizing a magnet of a magnetic resonance imaging facility includes a first circuit part, a second circuit part and a control facility. In an embodiment, the first circuit part is designed to generate a direct voltage as an DC link voltage from an alternating voltage and the second circuit part is designed as a current source fed by the DC link voltage. The second circuit part includes a down converter controllable by the control facility, a transformer switchable by the control facility and a rectifier. A primary current is generatable from the DC link voltage via the down converter. The primary current is feedable by a switching facility, switched by the control facility into a primary side of the transformer, and a secondary current for energizing the magnet is generatable via the rectifier connected to a secondary side of the transformer.
Superconducting Magnet for MRI System, and Processing Tool and Processing Method Therefor
A processing tool for a superconducting magnet of an MRI system is disclosed. The processing tool comprising a first winding part and a second winding part. The first winding part is used as a winding framework for winding a main coil half-body. The second winding part is used as a winding framework for winding a shield coil. The processing tool has an infusion cavity. The infusion cavity comprises a main coil accommodating zone, a shield coil accommodating zone, and a linking zone. The main coil accommodating zone is used for accommodating the main coil half-body wound on the first winding part. The shield coil accommodating zone is used for accommodating the shield coil wound on the second winding part. The main coil accommodating zone is connected to the shield coil accommodating zone via the linking zone. The processing tool helps to reduce the difficulty of superconducting magnet processing.
Support Structure for Superconducting Coil
An assembly of supported superconducting coils may include support structure including a flexible mounting band attached to a surface of a coil and which extends axially beyond the radially outer surface of the coil. The flexible mounting band may be attached to a support structure at multiple locations. The coil may be attached to one or more other coils by the flexible mounting band.
Support Structure for Superconducting Coil
An assembly of supported superconducting coils may include support structure including a flexible mounting band attached to a surface of a coil and which extends axially beyond the radially outer surface of the coil. The flexible mounting band may be attached to a support structure at multiple locations. The coil may be attached to one or more other coils by the flexible mounting band.
Method for charging a superconductor magnet system, with a main superconductor bulk magnet and a shield superconductor bulk magnet
Charging method for a superconductor magnet system with reduced stray field, weight and space includes: arranging the system within a charger magnet bore; with T.sub.main>T.sub.main.sup.crit and T.sub.shield>T.sub.shield.sup.crit, applying a current I.sub.charger to the charger magnet and increasing I.sub.charger to a first current I.sub.1>0; lowering a main superconductor bulk magnet temperature T.sub.main to an operation temperature T.sub.main.sup.op, with T.sub.main.sup.op<T.sub.main.sup.crit, while keeping T.sub.shield>T.sub.shield.sup.crit; lowering I.sub.charger to a second current I.sub.2<0, thereby inducing a persistent current IP.sub.main in the main magnet; lowering a shield magnet temperature T.sub.shield to an operation temperature T.sub.shield.sup.op, with T.sub.shield.sup.op<T.sub.shield.sup.crit; increasing I.sub.charger to zero, thereby inducing a persistent current IP.sub.shield in the shield magnet; removing the magnet system from the charger bore, and keeping T.sub.main≤T.sub.main.sup.op with T.sub.main.sup.op<T.sub.main.sup.crit and T.sub.shield≤T.sub.shield.sup.op with T.sub.shield.sup.op<T.sub.shield.sup.crit; where: T.sub.main.sup.crit: main magnet critical temperature and T.sub.shield.sup.crit: shield magnet critical temperature.
Systems and methods for magnetic resonance imaging
The present disclosure relates to systems and methods for magnetic resonance imaging (MRI). The systems may include a gradient coil assembly configured to form a gradient magnetic field. The systems may also include a cryostat including a superconducting coil assembly and a magnetic field shielding apparatus arranged on/in a component of the cryostat. The superconducting coil assembly may be configured to form a main magnetic field. The magnetic field shielding apparatus may be configured to shield the superconducting coil assembly from a stray field of the gradient coil assembly. The magnetic field shielding apparatus may include a conductive shielding component, a shielding cylinder, or a combination thereof.
ACCESSIBLE MAGNETIC RESONANCE IMAGING SYSTEM
An ambulance-compatible magnetic resonance imaging (MRI) system for on-site emergency diagnosis includes a mid-field super-conducting head-only magnet including a bore and an active shield arranged relative to the magnet, a passive shield arranged relative to the magnet, the passive shield including a first flange arranged adjacent to a first side of the magnet bore, a second flange arranged adjacent to a second side of the magnet bore, wherein the first flange and the second flange are electrically connected to each other, and wherein the passive shield is operative to capture flux extending out from the magnet bore and return the flux to the magnet. An asymmetric head gradient assembly for generating magnetic gradient field in the mid-field super-conducting magnet is also provided, the magnetic gradient field being between 100-150 mT/m or having a slew rate between 400-800 T/m/s. The MRI system includes a receiver coil and a controller operatively coupled to the receive coil, the controller configured to produce an image based on data obtained from the receive coil. The MRI system is mountable in an ambulance vehicle.