G01R33/4215

BRAIN MEASUREMENT APPARATUS AND BRAIN MEASUREMENT METHOD

A brain measurement apparatus includes: a magnetoencephalograph including optically pumped magnetometers, magnetic sensors for measuring a static magnetic field at positions of the optically pumped magnetometers, and a nulling coil for canceling the static magnetic field; an MRI apparatus including a permanent magnet, a gradient magnetic field coil, a transmission coil, and a receive coil for detecting a nuclear magnetic resonance signal; and a control device that, when measuring the brain's magnetic field, controls a current to be supplied to the nulling coil based on measured values of the magnetic sensors and operates so as to cancel a static magnetic field at the position of each of the optically pumped magnetometers and, when measuring an MR image, controls the gradient magnetic field by controlling a current to be supplied to the gradient magnetic field coil and generates an MR image based on an output of the receive coil.

SYSTEMS AND METHODS FOR RECORDING BIOMAGNETIC FIELDS OF THE HUMAN HEART

A magnetocardiography (MCG) system includes a passively shielded enclosure having walls defining the passively shielded enclosure, each of the walls including passive magnetic shielding material to reduce an ambient background magnetic field within the passively shielded enclosure; an MCG measurement device including optically pumped magnetometers (OPMs); and active shield coils within the passively shielded enclosure and stationary relative to the passively shielded enclosure and the MCG measurement device, wherein the active shield coils are configured to further reduce the ambient background magnetic field within a user area of the passively shielded enclosure.

Method to isolate resonant radio frequency (RF) coils

Various embodiments of the present disclosure are directed towards a radio frequency (RF) coil comprising a first combination coil and a second combination coil. The first combination coil comprises a first resonant coil and a first resonant shield coupled inductively or by a capacitor, and the first combination coil has a first resonant frequency and a second resonant frequency. The second combination coil comprises a second resonant coil and a second resonant shield coupled inductively or by a capacitor, and the second combination coil has a third resonant frequency and a fourth resonant frequency. The first and second resonant coils are inductively coupled to each other and respectively to the second and first resonant shields. The first and third resonant working frequencies are the same, and the second and fourth resonant isolation frequencies are such that inductive coupling between the first and second resonant coils is negated.

Gradient coil structure for heat power reduction
11346907 · 2022-05-31 · ·

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.

Method of designing a high shielding gradient coil for a planar superconducting magnetic resonance imaging system and gradient coil thereof
11740303 · 2023-08-29 ·

The present application provides a method of designing a high shielding gradient coil for a planar superconducting magnetic resonance imaging (MRI) system and a gradient coil thereof, the method determines a shielding area according to an outer profile of a metal conductor around the position of the gradient coil in the planar superconducting MRI system, and performs partitioned shielding of a stray field. The constraint values of stray fields at different partitioned zones of the shielding area are adjusted according to the shielding requirements. The primary coils of both the transverse gradient coil and the longitudinal gradient coil optimized by the design method of the high shielding gradient coil contain a reverse coil, which generates a magnetic field that offsets leakage magnetic field of other coils, thus achieving the purpose of reducing the stray field of the gradient coil.

RADIATION THERAPY SYSTEM AND METHOD

The present disclosure relates to a therapeutic apparatus including an MRI apparatus configured to acquire MRI data with respect to a region of interest. The MRI apparatus may include a plurality of main magnetic field coils coaxially arranged along an axis. The MRI apparatus may also include a plurality of shielding coils arranged coaxially along the axis. A current within at least one of the shielding coils may be in the same direction with a current within the main magnetic field coils.

Open-type magnetic resonance imaging apparatus

An open-type MRI apparatus includes a pair of static magnetic field magnets and a pair of gradient magnetic field coils. Each static magnetic field magnet includes a discoid magnetic pole configured to generate a static magnetic field in a Z axis direction in which the pair of static magnetic field magnets are opposed each other, and an annular magnetic pole configured to generate a static magnetic field on an X-Y plane perpendicular to the Z axis direction. Each gradient magnetic field coil includes a Z coil configured to provide a magnetic field being gradient in the Z axis direction in the imaging region, a magnetic material block configured to shield the discoid magnetic pole from a magnetic flux generated from the Z coil, and a correction coil configured to shield the annular magnetic pole from the magnetic flux generated from the Z coil.

MAGNETS AND MAGNETIC RESONANCE IMAGING SYSTEMS
20220128638 · 2022-04-28 ·

A magnet suitable for use in a Magnetic Resonance Imaging (MRI) system. The magnet includes a magnet body having a bore extending therethrough along an axis of the body and a primary coil structure having at least four primary coils positioned along the axis. A first end coil is adjacent a first end of the bore of the magnet and a second end coil is adjacent a second end of the magnet. The first end coil and the second end coil are spaced apart by no more than 1000 mm and an imaging region produced by the primary coils is of a disk-type.

Gradient coil assembly for a magnetic resonance apparatus
11181593 · 2021-11-23 · ·

A gradient coil assembly for a magnetic resonant apparatus has a primary coil and a secondary coil, wherein the primary coil has a first primary coil winding and a second primary coil winding, wherein the first primary coil winding and the second primary coil winding are electrically connected to a voltage source and are jointly designed to generate a magnetic field gradient in a direction when the voltage source induces a current in those windings.

GRADIENT COIL SYSTEM
20220011387 · 2022-01-13 · ·

A gradient coil system suitable for use in an MRI system. The gradient coil system having a gradient body having a bore extending therethrough and at least one frustoconical portion arranged about the bore. A diameter of a first end of the bore is greater than a diameter of a second end of the bore. The gradient coil system also includes a gradient coil assembly arranged about the bore having at least one frustoconical section substantially conforming to the at least one frustoconical portion of the body, the gradient coil assembly generating gradient fields in a Diameter of Spherical Volume (DSV) for medical imaging.