Abstract: A system and method for enhancing magnetic resonance imaging is described. The method includes a declarative style of pulse sequence design that incorporates explicit objectives. Each objective includes the function and context of the waveform; environmental and contextual data; time segment durations; spatial magnetic field profiles of the encoding electromagnets; and performance metrics.

Abstract: A coil apparatus and methods for magnetic resonance imaging involving a wire winding, the wire winding having at least one of: a hollow cross-section wire and a solid cross-section wire, the solid cross-section wire having at least one of: a solid small cross-section wire and a solid large cross-section wire, the solid large cross-section wire having a thickness greater than that of the solid small cross-section wire, and the solid small cross-section wire disposed in one of adjacent and proximate at least one of the hollow cross-section wire and the solid large cross-section wire, whereby at least one of current density, winding density, and heat extraction are increasable.

Abstract: Systems and methods for imaging a subject with a magnetic resonance imaging system using magnetic field gradients generated by one or more gradient coils operating with gradient coil settings, such as gradient amplitudes and gradient slew rates, above a threshold at which peripheral nerve stimulation is likely to be induced in the subject. A dielectric assembly is positioned adjacent a skin surface of the subject such that the dielectric assembly attenuates the local electric fields induced by the magnetic field gradients, which would be likely to induce PNS when the dielectric assembly is not arranged adjacent the skin surface of the subject. As a result of the dielectric assembly placed adjacent the skin surface of the subject, the gradient coil settings can be increased above the threshold without inducing PNS in the subject.

Abstract: A method of manufacturing an electromagnet coil for use in a magnetic resonance imaging (MRI) system includes: generating a coil surface representation defining a surface to contain the electromagnet coil; defining a set of performance metric functions, the set including a mutual inductance function defining mutual inductance between the electromagnet coil and a second electromagnet coil; defining a performance functional based on the coil surface representation and the set of performance metric functions; optimizing the performance functional; generating a current density pattern over the coil surface representation based on the optimized performance functional; and obtaining coil windings defining the electromagnet coil from the current density pattern.

Abstract: Magnetic resonance imaging (MRI) systems and methods, involving: a main magnet configured to generate a magnet field for MRI; a transmit radio frequency (RF) coil assembly configured to transmit an RF pulse into a portion of a subject; an RF coil assembly configured to, in response to the an RF pulse, receive MR signals emitted from the portion of the subject; and a gradient coil assembly having coil windings arranged in a radial layer and a first set of electrical connectors embedded in the radial layer to reduce a radial extent occupied by the gradient coil assembly, an electrical connector in the first set of electrical connectors configured to cross over a portion of the coil windings in the radial layer, the first set of electrical connectors configured to drive the coil windings with a current sufficient to generate a perturbation in the magnet field such that the MR signals encode an MR image based on the perturbation, and the radial layer having a depressed area configured to radially constrain the el

Abstract: 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.

Abstract: Systems and methods for imaging a subject with a magnetic resonance imaging system using magnetic field gradients generated by one or more gradient coils operating with gradient coil settings, such as gradient amplitudes and gradient slew rates, above a threshold at which peripheral nerve stimulation is likely to be induced in the subject. A dielectric assembly is positioned adjacent a skin surface of the subject such that the dielectric assembly attenuates the local electric fields induced by the magnetic field gradients, which would be likely to induce PNS when the dielectric assembly is not arranged adjacent the skin surface of the subject. As a result of the dielectric assembly placed adjacent the skin surface of the subject, the gradient coil settings can be increased above the threshold without inducing PNS in the subject.

Abstract: The present disclosure reports on a method to first determine the required electromagnetic stream function, and then iterate on the contouring of the stream function to optimize the force, torque, shielding, and/or mutual inductance of the design after-the-fact without compromising the electromagnetic performance and an electromagnetic coil manufacture according to the method. These parameters are sensitive to the precise positioning of the discrete wires.

Abstract: Magnetic resonance imaging (MRI) systems and methods, involving: a main magnet configured to generate a magnet field for MRI; a transmit radio frequency (RF) coil assembly configured to transmit an RF pulse into a portion of a subject; an RF coil assembly configured to, in response to the an RF pulse, receive MR signals emitted from the portion of the subject; and a gradient coil assembly having coil windings arranged in a radial layer and a first set of electrical connectors embedded in the radial layer to reduce a radial extent occupied by the gradient coil assembly, an electrical connector in the first set of electrical connectors configured to cross over a portion of the coil windings in the radial layer, the first set of electrical connectors configured to drive the coil windings with a current sufficient to generate a perturbation in the magnet field such that the MR signals encode an MR image based on the perturbation, and the radial layer having a depressed area configured to radially constrain the el

Abstract: An asymmetric electromagnet system, method, and method of producing an asymmetric electromagnet system, wherein the asymmetric electromagnet system is for generating an imaging magnetic field in an imaging region with an imaging isocentre, the imaging region being asymmetrically positioned within a gradient coil bore inside a magnetic resonance imaging (MRI) system during imaging, the electromagnet assembly comprising: an asymmetric gradient coil configured to generate a gradient field in the asymmetrically positioned imaging region, at least one gradient axis having the gradient field with a constant offset component such that the position at which the gradient field passes through zero is offset with respect to the imaging isocentre of the asymmetrically positioned imaging region.

Abstract: A coil apparatus and methods for magnetic resonance imaging involving a wire winding, the wire winding having at least one of: a hollow cross-section wire and a solid cross-section wire, the solid cross-section wire having at least one of: a solid small cross-section wire and a solid large cross-section wire, the solid large cross-section wire having a thickness greater than that of the solid small cross-section wire, and the solid small cross-section wire disposed in one of adjacent and proximate at least one of the hollow cross-section wire and the solid large cross-section wire, whereby at least one of current density, winding density, and heat extraction are increasable.

Abstract: A magnetic resonance (MR) imaging system includes: a main magnet configured to generate a volume of magnet field suitable for forming MR imaging; a transmit radio frequency (RF) coil assembly configured to transmit at least one RF signal; a receive radio frequency (RF) coil assembly configured to, in response to the at least one RF pulse, receive MR signals; a gradient coil assembly comprising (i) windings of coils arranged in a radial layer, and (ii) a first set of connectors embedded in the radial layer to reduce a radial extent occupied by the gradient coil assembly, the first set of electrical connectors configured to drive the windings of coils; and a control unit coupled to the transmit RF coil assembly, the receive RF coil assembly, and the gradient coils, the control unit configured to synchronously operate the gradient coil assembly, the transmit coil assembly, and the receive coil assembly.

Abstract: A coil apparatus and methods for magnetic resonance imaging involving a wire winding, the wire winding having at least one of: a hollow cross-section wire and a solid cross-section wire, the solid cross-section wire having at least one of: a solid small cross-section wire and a solid large cross-section wire, the solid large cross-section wire having a thickness greater than that of the solid small cross-section wire, and the solid small cross-section wire disposed in one of adjacent and proximate at least one of the hollow cross-section wire and the solid large cross-section wire, whereby at least one of current density, winding density, and heat extraction are increasable.

Abstract: An asymmetric electromagnet system, method, and method of producing an asymmetric electromagnet system, wherein the asymmetric electromagnet system is for generating an imaging magnetic field in an imaging region with an imaging isocentre, the imaging region being asymmetrically positioned within a gradient coil bore inside a magnetic resonance imaging (MRI) system during imaging, the electromagnet assembly comprising: an asymmetric gradient coil configured to generate a gradient field in the asymmetrically positioned imaging region, at least one gradient axis having the gradient field with a constant offset component such that the position at which the gradient field passes through zero is offset with respect to the imaging isocentre of the asymmetrically positioned imaging region.

Abstract: An MRI-CT system and methods for sequentially (or simultaneously) imaging a subject involving a CT component for initially performing CT imaging, an MR component for subsequently performing MR imaging, the MR component and the CT component disposable in relation to one another in at least one of linearly aligned and colinearly aligned, and a movable barrier disposable between the CT component and the MR component, the movable barrier comprising a magnetic shield, and the movable barrier disposable in one of an open position and a closed position during MRI scanning by the MR component and in a closed position during CT scanning by the CT component.

Abstract: An asymmetric electromagnet system, method, and method of producing an asymmetric electromagnet system, wherein the asymmetric electromagnet system is for generating an imaging magnetic field in an imaging region with an imaging isocentre, the imaging region being asymmetrically positioned within a gradient coil bore inside a magnetic resonance imaging (MRI) system during imaging, the electromagnet assembly comprising: an asymmetric gradient coil configured to generate a gradient field in the asymmetrically positioned imaging region, at least one gradient axis having the gradient field with a constant offset component such that the position at which the gradient field passes through zero is offset with respect to the imaging isocentre of the asymmetrically positioned imaging region.

Abstract: Some implementations provide an MRI system that includes: a housing having a bore accommodating a portion of a subject; a main magnet enclosed by said housing and configured to generate a substantially uniform magnet field within the bore; a gradient sub-system to provide perturbations to the substantially uniform magnet field; a flexible coil assembly configured to (i) receive radio frequency (RF) signals from the subject in response to the portion of the subject being scanned, and (ii) generate and apply B0 shimming to improve a field homogeneity of the substantially uniform magnetic field; and a control unit configured to: drive the gradient sub-system using a gradient waveform; and receive measurement results responsive to the gradient waveform such that a coupling between the gradient sub-system and the flexible coil assembly is determined and subsequently reduced in response to the determined coupling exceeding a pre-determined threshold.

Abstract: The present disclosure reports on a method to first determine the required electromagnetic stream function, and then iterate on the contouring of the stream function to optimize the force, torque, shielding, and/or mutual inductance of the design after-the-fact without compromising the electromagnetic performance and an electromagnetic coil manufacture according to the method. These parameters are sensitive to the precise positioning of the discrete wires.

Abstract: A coil apparatus and methods for magnetic resonance imaging involving a wire winding, the wire winding having at least one of: a hollow cross-section wire and a solid cross-section wire, the solid cross-section wire having at least one of: a solid small cross-section wire and a solid large cross-section wire, the solid large cross-section wire having a thickness greater than that of the solid small cross-section wire, and the solid small cross-section wire disposed in one of adjacent and proximate at least one of the hollow cross-section wire and the solid large cross-section wire, whereby at least one of current density, winding density, and heat extraction are increasable.

Abstract: A method of manufacturing an electromagnet coil for use in a magnetic resonance imaging (MRI) system includes: generating a coil surface representation defining a surface to contain the electromagnet coil; defining a set of performance metric functions, the set including a mutual inductance function defining mutual inductance between the electromagnet coil and a second electromagnet coil; defining a performance functional based on the coil surface representation and the set of performance metric functions; optimizing the performance functional; generating a current density pattern over the coil surface representation based on the optimized performance functional; and obtaining coil windings defining the electromagnet coil from the current density pattern.