G01R33/3854

Noise suppression methods and apparatus

According to some aspects, a method of suppressing noise in an environment of a magnetic resonance imaging system is provided. The method comprising estimating a transfer function based on multiple calibration measurements obtained from the environment by at least one primary coil and at least one auxiliary sensor, respectively, estimating noise present in a magnetic resonance signal received by the at least one primary coil based at least in part on the transfer function, and suppressing noise in the magnetic resonance signal using the noise estimate.

Radio-frequency coil signal chain for a low-field MRI system

A radio-frequency (RF) coil for use in a low-field magnetic resonance imaging system and methods of making the same are provided. The RF coil may include a conductor arranged on a substrate in an arrangement such that symmetry in the arrangement cancels at least a portion of a common mode voltage when a current is passed through the conductor. The RF coil may be included in a magnetic resonance imaging (MRI) system for imaging a patient having at least one B.sub.0 magnet for generating a B.sub.0 magnetic field.

Thermal shield of magnetic resonance imaging magnet for limiting magnet gradient interaction

A system for minimizing MGI in a superconducting magnet system of an MRI system includes a thermal shield having bi-metal material. The thermal shield is configured to be disposed about a cold mass of the superconducting magnet system, wherein the bi-metal material is configured to minimize MGI.

SYSTEM AND METHOD FOR NOISE REDUCTION

The present disclosure provides a system for active noise cancellation for a subject placed in a scanning bore of a medical imaging apparatus. The system may be directed to perform operations including obtaining a real-time position of each of at least one target portion of a subject; obtaining signals from one or more arrays of noise detection units surrounding the subject; and directing, based on the signals obtained from the one or more arrays of noise detection units, one or more arrays of denoising units to produce a sound to counteract noise at the real-time position of each of the at least one target portion of the subject.

MRI DEVICE WITH PLASMA CONDUCTOR
20170371014 · 2017-12-28 ·

Apparatus for a nuclear resonance imaging (MRI) machine (100) that includes plasma elements (104, 106, 108). The MRI machine (100) includes gradient coils (104) that generate time-dependent gradient magnetic fields, transmitting elements (106) that excite target molecules (120) with RF energy (122), and receiving elements (108) responsive to RF energy (124) emitted by the excited molecules (120). The gradient coils (104) include plasma conductors (710) in which the plasma (716) is ignited by an exciter (208). The plasma conductors (710) are electrically connected to a gradient amplifier (206) that outputs a signal to produce the gradient fields. The transmitting elements (106) are plasma devices (710) configured to emit RF energy (122). The receiving elements (108) are plasma devices (710) responsive to emitted RF energy (124). An RF exciter (218) selectively and alternatingly ignites said plasma devices (710) to avoid coupling and interference between them.

HEAD-DEDICATED MAGNETIC RESONANCE IMAGING DEVICE
20230200674 · 2023-06-29 · ·

The present disclosure relates to a head-dedicated magnetic resonance imaging (MRI) device, wherein a head-dedicated image is acquired in a state in which a head of a subject is positioned in a center of a magnetic field of a main magnet installed in a housing, a local coil manufactured in in the form of being inserted into or worn in a human body of the subject is utilized to acquire an image of a selected portion to be examined (for example, an oral region, an ear region, and an eye region) of the head, or a vibration absorber installed around the housing absorbs vibrations caused by the Lorentz force generated by a magnetic field of the main magnet and a current applied to a gradient coil while the image is acquired in a state in which the housing is hung on an installation frame.

CABLE FOR OPERATING A GRADIENT COIL OF A MAGNETIC RESONANCE APPARATUS
20170371013 · 2017-12-28 ·

A cable for operating a gradient coil of a magnetic resonance apparatus, a magnetic resonance apparatus, and a method for manufacturing a cable for operating a gradient coil of a magnetic resonance apparatus are provided. The cable includes at least one electric conductor and a stabilizing sheathing that surrounds the at least one electric conductor at least partially.

Optimization of the noise development of a 3D gradient echo sequence in a magnetic resonance system

In a method according to optimize the noise development of a 3D gradient echo sequence in a magnetic resonance system, an optimization of at least one parameter of the gradient echo sequence, from the group including: the excitation pulse (the duration of the excitation pulse); the order of k-space lines to be scanned in k-space; and the readout direction of the k-space lines to be scanned in k-space, is implemented such that the gradients to be switched have optimally minimal slew rates, amplitudes and/or polarity changes.

SYSTEM AND METHOD FOR ELECTROMAGNET COIL CONSTRUCTION
20170356971 · 2017-12-14 ·

A method of manufacturing electromagnet coils for use in a magnetic resonance imaging (MRI) system is provided. The electromagnet coils are located in a non-homogeneous external magnetic field. The method comprises forming a coil representation of a coil surface for the electromagnet coils; setting limits for performance metrics for the electromagnet coils including a magnetic field-shape metric and at least one of an external torque metric and an external force metric, the external torque metric and the external force metric based, respectively, at least in part on a torque and a force exerted on the electromagnet coil by the non-homogeneous external magnetic field; forming a performance functional, based on the coil representation and the performance metrics, for generating a current density pattern over the coil surface; optimizing the performance functional and generating a current density pattern based on the optimized performance functional; and obtaining coil windings.

QUIET MRI USING ALTERNATING GRADIENT SEQUENCE
20170356972 · 2017-12-14 ·

Magnetic resonance imaging (MRI) systems and methods to effect MRI data acquisition with reduced noise are described. A readout gradient, having a first polarity used to acquire and store MRI data in k-space memory during analog-to-digital conversion (ADC) of MR RF signals during one TR interval, is continued at substantially a same amplitude and vector direction and used as an image volume selection gradient during a transmitted RF excitation pulse that begins a next TR interval before the readout gradient transitions to an opposite polarity. The acquired k-space data is then used to generate an MR image.