G01R33/3852

Gradient waveform design for low-field magnetic resonance imaging systems

Systems and methods for generating a gradient waveform for use by a low-field MRI system to generate a gradient magnetic field are provided herein. The gradient waveform can be determined using first information indicative of the gradient waveform and second information indicative of hardware constraints of the low-field MRI system including a maximum voltage of the gradient power amplifier, a maximum slew rate of the gradient coil, a resistance of the gradient coil, and an inductance of the gradient coil. In some embodiments, the gradient waveform can be a trapezoidal gradient waveform determined to have a non-linear ramp-up portion and/or a non-linear ramp-down portion.

Gradient coil unit for a magnetic resonance device including an eddy current compensating conductor structure
11422215 · 2022-08-23 · ·

The disclosure relates to a gradient coil unit comprising at least one first conductor structure, which is configured to generate a magnetic field gradient in a first direction, and an eddy current compensating conductor structure, which is configured to compensate for a first magnetic field. The first magnetic field is generated by a current induced in the first conductor structure as a result of activation of a conductor structure comprised by the gradient coil unit.

METHOD FOR ACQUIRING MAGNETIC RESONANCE (MR) DATA

Techniques are described for acquiring MR data comprising first MR data and second MR data of an examination object using an MR control sequence and a magnetic resonance device comprising an amplifier unit and an analog-to-digital converter (ADC).

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.

Magnetic resonance device and method for recording magnetic resonance data using a magnetic resonance device
11294007 · 2022-04-05 · ·

A magnetic resonance device (1), having a main magnet unit (2) with a cylindrical patient aperture (3), wherein at least one radial gradient coil (9) is provided in the patient aperture (3) which generates a gradient field having, at least in regions, a radial gradient in relation to its own central axis parallel to the longitudinal axis of the patient aperture (3), the radial gradient coil (9) being embodied as a cylinder coil.

Method for controlling patient stimulating effects in magnetic resonance imaging, corresponding computer program and computer-readable storage medium, and magnetic resonance imaging device

Methods and systems for controlling patient stimulating effects in MR imaging. The methods and systems include calculating a first effective stimulus duration independently for each pulse flank of an MRI sequence individually and calculating a second effective stimulus duration for which a respective history of a changing gradient field during the sequence is taken into account. Dependent on an evaluation of both the first and second effective stimulus durations a threshold value for an allowable rate of change in the magnetic gradient field is then calculated. The respective MRI sequence is then evaluated against the calculated threshold value to determine whether or not the respective MRI sequence is safe to apply.

Method for determining and eliminating time delay between radio frequency pulse and layer selection gradient in a magnetic resonance device
11280864 · 2022-03-22 · ·

The present application describes techniques for determining and eliminating a time delay between a radio frequency pulse and a layer selection gradient in a magnetic resonance device. The techniques for determining and eliminating the time delay direct include measuring the time delay between the layer selection gradient and the radio frequency pulse by using phase information. This technique is more sensitive and accurate than existing methods that use signal or artifact strength.

Shield-free MRI system of time-varying electromagnetic fields in complex electromagnetic environments

The present disclosure relates to a method and a system for minimizing electromagnetic interference (EMI) of magnetic resonance imaging (MRI) systems in complex electromagnetic environments. The method and system described herein provide superior MRI image quality and may reduce costs by eliminating the requirement of expensive shielding in MRI systems/hybrid MRI systems.

Method of reducing spatial extent of gradient coil current feeding connectors

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.

System and method for monitoring health status of a gradient coil

A system for monitoring a health status of a gradient coil disposed in a magnetic resonance imaging system is provided. The system includes one or more sensors and a controller. The one or more sensors are operative to obtain one or more parameter readings of the gradient coil, wherein the one or more parameter readings include at least one of an acoustic measurement and a back electromotive force measurement. The controller is in electronic communication with the one or more sensors and operative to generate the health status based on at least one of the acoustic measurement and the back electromotive force measurement.