Abstract: According to some aspects, a magnetic resonance imaging system capable of imaging a patient is provided. The magnetic resonance imaging system comprising at least one B0 magnet to produce a magnetic field to contribute to a B0 magnetic field for the magnetic resonance imaging system and a member configured to engage with a releasable securing mechanism of a radio frequency coil apparatus, the member attached to the magnetic resonance imaging system at a location so that, when the member is engaged with the releasable securing mechanism of the radio frequency coil apparatus, the radio frequency coil apparatus is secured to the magnetic resonance imaging system substantially within an imaging region of the magnetic resonance imaging system.

Abstract: A low-field magnetic resonance imaging (MRI) system. The system includes a plurality of magnetics components comprising at least one first magnetics component configured to produce a low-field main magnetic field B0 and at least one second magnetics component configured to acquire magnetic resonance data when operated, and at least one controller configured to operate one or more of the plurality of magnetics components in accordance with at least one low-field zero echo time (LF-ZTE) pulse sequence.

Abstract: Some aspects comprise a tuning system configured to tune a radio frequency coil for use with a magnetic resonance imaging system comprising a tuning circuit including at least one tuning element configured to affect a frequency at which the radio frequency coil resonates, and a controller configured to set at least one value for the tuning element to cause the radio frequency coil to resonate at approximately a Larmor frequency of the magnetic resonance imaging system determined by the tuning system. Some aspects include a method of automatically tuning a radio frequency coil comprising determining information indicative of a Larmor frequency of the magnetic resonance imaging system, using a controller to automatically set at least one value of a tuning circuit to cause the radio frequency coil to resonate at approximately the Larmor frequency based on the determined information.

Abstract: A magnetic resonance imaging (MRI) system, comprising a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, electromagnetic shielding provided to attenuate at least some electromagnetic noise in an operating environment of the MRI system, and an electrical conductor coupled to the electromagnetic shielding and configured to electrically couple to a patient during imaging of the patient by the MRI system. The magnetics system may include at least one permanent B0 magnet configured to produce a B0 magnetic field for an imaging region of the MRI system. The B0 magnetic field strength may be less than or equal to approximately 0.2 T.

Abstract: 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 B0 magnet for generating a B0 magnetic field.

Abstract: An apparatus to provide power for operating at least one gradient coil of a magnetic resonance imaging system. According to some aspects, the apparatus comprises a plurality of power terminals configured to supply different voltages of a first polarity, and a linear amplifier configured to provide at least one output to power the at least one gradient coil to produce a magnetic field in accordance with a pulse sequence, the linear amplifier configured to be powered by one or more of the plurality of power terminals, wherein the one or more of the plurality of power terminals powering the linear amplifier is selected based, at least in part, on the at least one output.

Abstract: According to some aspects, a low-field magnetic resonance imaging system is provided. The low-field magnetic resonance imaging system comprises a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, the magnetics system comprising, a B0 magnet configured to produce a B0 field for the magnetic resonance imaging system at a low-field strength of less than 0.

Abstract: According to some aspects, a magnetic resonance imaging system capable of imaging a patient is provided. The magnetic resonance imaging system comprising at least one B0 magnet to produce a magnetic field to contribute to a B0 magnetic field for the magnetic resonance imaging system and a member configured to engage with a releasable securing mechanism of a radio frequency coil apparatus, the member attached to the magnetic resonance imaging system at a location so that, when the member is engaged with the releasable securing mechanism of the radio frequency coil apparatus, the radio frequency coil apparatus is secured to the magnetic resonance imaging system substantially within an imaging region of the magnetic resonance imaging system.

Abstract: Some aspects comprise a tuning system configured to tune a radio frequency coil for use with a magnetic resonance imaging system comprising a tuning circuit including at least one tuning element configured to affect a frequency at which the radio frequency coil resonates, and a controller configured to set at least one value for the tuning element to cause the radio frequency coil to resonate at approximately a Larmor frequency of the magnetic resonance imaging system determined by the tuning system. Some aspects include a method of automatically tuning a radio frequency coil comprising determining information indicative of a Larmor frequency of the magnetic resonance imaging system, using a controller to automatically set at least one value of a tuning circuit to cause the radio frequency coil to resonate at approximately the Larmor frequency based on the determined information.

Abstract: An apparatus to provide power for operating at least one gradient coil of a magnetic resonance imaging system. According to some aspects, the apparatus comprises a plurality of power terminals configured to supply different voltages of a first polarity, and a linear amplifier configured to provide at least one output to power the at least one gradient coil to produce a magnetic field in accordance with a pulse sequence, the linear amplifier configured to be powered by one or more of the plurality of power terminals, wherein the one or more of the plurality of power terminals powering the linear amplifier is selected based, at least in part, on the at least one output.

Abstract: Methods and apparatus for reducing noise in RF signal chain circuitry for a low-field magnetic resonance imaging system are provided. A switching circuit in the RF signal chain circuitry may include at least one field effect transistor (FET) configured to operate as an RF switch at an operating frequency of less than 10 MHz. A decoupling circuit may include tuning circuitry coupled across inputs of an amplifier and active feedback circuitry coupled between an output of the amplifier and an input of the amplifier, wherein the active feedback circuitry includes a feedback capacitor configured to reduce a quality factor of an RF coil coupled to the amplifier.

Abstract: Methods and apparatus for operating a low-field magnetic resonance imaging (MRI) system to perform diffusion weighted imaging, the low-field MRI system including a plurality of magnetics components including a B0 magnet configured to produce a low-field main magnetic field B0, at least one gradient coil configured to, when operated, provide spatial encoding of emitted magnetic resonance signals, and at least one radio frequency (RF) component configured to acquire, when operated, the emitted magnetic resonance signals. The method comprises controlling one or more of the plurality of magnetics components in accordance with at least one pulse sequence having a diffusion-weighted gradient encoding period followed by multiple echo periods during which magnetic resonance signals are produced and detected, wherein at least two of the multiple echo periods correspond to respective encoded echoes having an opposite gradient polarity.

Abstract: A magnetic resonance (MR) imaging system, comprising a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, and a sensor configured to detect electromagnetic interference conducted by a patient into an imaging region of the MR imaging system. The sensor may comprise at least one electrical conductor configured for electrically coupling to the patient. The MR imaging system may further comprise a noise reduction system configured to receive the electromagnetic interference from the sensor and to suppress electromagnetic interference in detected MR signals received by the MR imaging system based on the electromagnetic interference detected by the sensor.

Abstract: A magnetic resonance (MR) imaging system, comprising a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, and a sensor configured to detect electromagnetic interference conducted by a patient into an imaging region of the MR imaging system. The sensor may comprise at least one electrical conductor configured for electrically coupling to the patient. The MR imaging system may further comprise a noise reduction system configured to receive the electromagnetic interference from the sensor and to suppress electromagnetic interference in detected MR signals received by the MR imaging system based on the electromagnetic interference detected by the sensor.

Abstract: 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 substrate having a first and second side and a conductor. The conductor may include a first portion wound around the substrate from the first side to the second side at a first plurality of locations spaced between the first side and the second side and a second portion wound around the substrate from the second side to the first side at a second plurality of locations spaced between the first side and the second side, wherein the first plurality of locations alternate with the second plurality of locations spaced between the first side and the second side.

Abstract: Some aspects include a method of detecting change in biological subject matter of a patient positioned within a low-field magnetic resonance imaging device, the method comprising: while the patient remains positioned within the low-field magnetic resonance device: acquiring first magnetic resonance image data of a portion of the patient; acquiring second magnetic resonance image data of the portion of the patient subsequent to acquiring the first magnetic resonance image data; aligning the first magnetic resonance image data and the second magnetic resonance image data; and comparing the aligned first magnetic resonance image data and second magnetic resonance image data to detect at least one change in the biological subject matter of the portion of the patient.

Abstract: A low-field magnetic resonance imaging (MRI) system. The system includes a plurality of magnetics components comprising at least one first magnetics component configured to produce a low-field main magnetic field B0 and at least one second magnetics component configured to acquire magnetic resonance data when operated, and at least one controller configured to operate one or more of the plurality of magnetics components in accordance with at least one low-field zero echo time (LF-ZTE) pulse sequence.

Abstract: Methods and apparatus for reducing noise in RF signal chain circuitry for a low-field magnetic resonance imaging system are provided. A switching circuit in the RF signal chain circuitry may include at least one field effect transistor (FET) configured to operate as an RF switch at an operating frequency of less than 10 MHz. A decoupling circuit may include tuning circuitry coupled across inputs of an amplifier and active feedback circuitry coupled between an output of the amplifier and an input of the amplifier, wherein the active feedback circuitry includes a feedback capacitor configured to reduce a quality factor of an RF coil coupled to the amplifier.

Abstract: According to some aspects, a low-field magnetic resonance imaging system is provided. The low-field magnetic resonance imaging system comprises a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, the magnetics system comprising, a B0 magnet, a plurality of gradient coils, and at least one radio frequency coil, a power system comprising one or more power components configured to provide power to the magnetics system to operate the magnetic resonance imaging system to perform image acquisition, and a power connection configured to connect to a single-phase outlet to receive mains electricity and deliver the mains electricity to the power system to provide power needed to operate the magnetic resonance imaging system.