Patent classifications
G01R33/3852
SAFETY STRUCTURE OF A MAGNETIC RESONANCE APPARATUS
A magnetic resonance apparatus with a safety structure for monitoring a safety-related function is provided. The safety structure includes a control path that is configured to control the safety-related function, and a first protect path and a second protect path. The first protect path and the second protect path are configured to acquire a safety-related parameter of the safety-related function. The first protect path is configured to identify a hazardous situation, independently of the control path and the second protect path, based on the safety-related parameter that the first protect path acquires. The second protect path is configured to identify a hazardous situation, independently of the control path and the first protect path, based on the safety-related parameter that the second protect path acquires. The first protect path and the second protect path are each configured to transfer the magnetic resonance apparatus into a safe state in a hazardous situation.
Low field magnetic resonance imaging methods and apparatus
According to some aspects, a laminate panel is provided. The laminate panel comprises at least one laminate layer including at least one non-conductive layer and at least one conductive layer patterned to form at least a portion of a B.sub.0 coil configured to contribute to a B.sub.0 field suitable for use in low-field magnetic resonance imaging (MRI).
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.
ELECTROMAGNETIC SHIELDING FOR MAGNETIC RESONANCE IMAGING METHODS AND APPARATUS
According to some aspects, a portable magnetic resonance imaging system is provided, comprising a Bo magnet configured to produce a Bo magnetic field for an imaging region of the magnetic resonance imaging system, a noise reduction system configured to detect and suppress at least some electromagnetic noise in an operating environment of the portable magnetic resonance imaging system, and electromagnetic shielding provided to attenuate at least some of the electromagnetic noise in the operating environment of the portable magnetic resonance imaging system, the electromagnetic shielding arranged to shield a fraction of the imaging region of the portable magnetic resonance imaging system. According to some aspects, the electromagnetic shield comprises at least one electromagnetic shield structure adjustably coupled to the housing to provide electromagnetic shielding for the imaging region in an amount that can be varied. According to some aspects, substantially no shielding of the imaging region is provided.
Magnetic resonance imaging apparatus and method of compensating for error magnetic field
Provided are MRI images with excellent image quality and in which the occurrence of artifacts is suppressed by effectively removing a secondary error magnetic field, generated by compensation current (additional current), of eddy current that is caused by applying a gradient magnetic field. The present invention measures and analyzes, in advance, a secondary error magnetic field generated due to the applying of compensation current and saves the results as compensation parameters (secondary compensation parameters), uses the secondary compensation parameters to calculate a correction magnetic field output to be applied to each of a gradient magnetic field coil and a correction coil, and supplies this correction magnetic field output to the gradient magnetic field coil and the correction coil to compensate for (cancel out) the secondary error magnetic field.
SYSTEM AND METHOD FOR OPERATION AND CONTROL OF ELECTROMAGNETS
A system and method for compensation of radiofrequency (RF) spatial encoding misalignment errors due to gradient non-linearity in magnetic resonance imaging is described. The true magnetic field produced by the gradient coils in space are taken into account in order to encode the appropriate frequency band and offset of the RF pulse corresponding to the desired spatial encoding position and thickness. This method is applicable to any positionally (frequency) encoded radiofrequency (RF) pulses including slice or slab excitation pulses, inversion pulses, spin echo (refocusing) pulses and spatial saturation pulses.
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.
SENSOR FOR DETECTING GRADIENT-BOUNDED INTERFERENCE TO A MAGNETIC RESONANCE TOMOGRAPHY SYSTEM AND METHOD FOR OPERATION
A magnetic resonance tomography system with a sensor for detecting spikes and with a gradient coil. Nuclear spins of an object under observation are excited by a magnetic alternating field of the magnetic resonance tomography system. A gradient field is generated by the magnetic resonance tomography system using the gradient coil. A magnetic resonance signal is acquired using a receiving antenna of the magnetic resonance tomography system and an interference signal using the sensor. From the magnetic resonance signal an image is reconstructed as a function of the acquired interference signal of the sensor.
Establishing Permitted Gradient Intensities to Prevent Overloading of a Magnetic Resonance (MR) System Gradient Unit
Permitted gradient intensities are established to prevent an overloading of a gradient unit of a magnetic resonance system during a recording, with the magnetic resonance system, of scan data from an examination object situated in a scan volume of said magnetic resonance system.
REDUCING AND CORRECTING MAGNETIC FIELD GRADIENT DEVIATIONS
A deviation from a target gradient of a magnetic field gradient created by an MR system is reduced or corrected. The MR system includes an amplifier, which amplifies an amplifier input signal and outputs an amplifier output signal, and a gradient coil, which creates the magnetic field gradient with the aid of the amplifier output signal. Input data is provided for a trained function trained by a machine-learning algorithm. The input data includes information about the target gradient of the MR system. Output data is created by the trained function with the aid of the input data. A gradient characterization function of the gradient coil is determined. The deviation from the target gradient of the magnetic field gradient created by the MR system is reduced and/or corrected. A deviation caused by the amplifier is reduced and/or corrected with the aid of the output data created, and a deviation caused by the gradient coil is reduced and/or corrected with the aid of the gradient characterization function.