Gradient coil assemblies for horizontal magnetic resonance imaging systems (MRIs) and methods of their manufacture. Some embodiments may be used with open MRIs and can be used with an instrument placed in the gap of the MRI. In general, concentrations of conductors or radially oriented conductors may be moved away from the gap of the MRI so as to reduce eddy currents that may be induced in any instrument placed within the gap. Systems for directly cooling primary gradient and shield coils may be utilized and various coil supporting structures may be used to assist in coil alignment or to facilitate use of an instrument in the MRI gap.

A superconductor magnet apparatus (2) includes a superconductor bulk magnet (9), a cryostat (7) and a ferromagnetic shielding body (11). The bulk magnet has a superconductor bore (10), an axis (z) of rotational symmetry, and a maximum outer diameter OD.sub.bm in a plane perpendicular to the z axis. The superconductor bore has a minimum cross-sectional area S.sub.bo in a plane perpendicular to the z axis. The cryostat has a room temperature bore (8), the bulk magnet is arranged within the cryostat and the room temperature bore is arranged within the superconductor bore. The shielding body has a shielding bore (12), the bulk magnet is arranged within the shielding bore and the shielding body extends beyond the bulk magnet at each axial end by at least OD.sub.bm/3. For an average cross-sectional area S.sub.fb of the shielding body, S.sub.fb2.5*S.sub.bo, and the shielding body is arranged within the cryostat.

System and methods that reconstruct absolute temperature using a multi-nuclear approach. Specifically, the methods and systems utilize independent NMR/MRI information provided by the precession frequency of two different nuclei to reconstruct a map of the absolute temperature.

Provided herein are embodiments of a Quadruple Butterfly Coil (QBC) configuration having enhanced focality for stimulation of specific areas of a brain for therapeutic treatment. Finite element simulations were conducted for the QBC, the QBC with a single shield, and the QBC with a double shield. The stimulation profiles for these coil configurations were assessed with 50 anatomically realistic MRI derived head models. The coils were positioned on the vertex and the scalp over the dorsolateral prefrontal cortex to stimulate the brain. Computer modeling of the coils was performed to determine volume of stimulation, maximum electric field, location of maximum electric field, and area of stimulation across all 50 head models for both coils.

A sample pipe is provided in a sample temperature control pipe. A detection coil is provided in a low-temperature airtight chamber and configured to irradiate a sample with a high-frequency magnetic field. A room-temperature shield is provided on an outer circumferential surface of the sample temperature control pipe or on an inner circumferential surface thereof, and is configured to block irradiation of the high-frequency magnetic field from the detection coil from reaching a region other than an observation object. A low-temperature shield is provided in an airtight chamber and between the detection coil and the room-temperature shield and is configured to block irradiation of the high-frequency magnetic field from the detection coil from reaching the room-temperature shield.

A magnetic resonance imaging (MRI) coil system is provided that includes a gradient coil and a flow inlet. The gradient coil includes a flow channel passing therethrough. The gradient coil defines an eye and an end. The eye is disposed proximate the center of the gradient coil. The flow inlet is disposed along the gradient coil between the eye and the end. Cooling fluid is provided to the gradient coil via the flow inlet, and removed from the gradient coil via the eye and the end.

According to some aspects, a portable magnetic resonance imaging system is provided, comprising a B.sub.0 magnet configured to produce a B.sub.0 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 of the portable magnetic resonance imaging system is provided.

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.

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 B.sub.0 magnet configured to produce a B.sub.0 field for the magnetic resonance imaging system at a low-field strength of less than 0.2 Tesla (T), a plurality of gradient coils configured to, when operated, generate magnetic fields to provide spatial encoding of magnetic resonance signals, and at least one radio frequency coil configured to, when operated, transmit radio frequency signals to a field of view of the magnetic resonance imaging system and to respond to magnetic resonance signals emitted from the field of view, 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. According to some aspects, the power system operates the low-field magnetic resonance imaging system using an average of less than 1.6 kilowatts during image acquisition.

According to some aspects, a portable magnetic resonance imaging system is provided, comprising a B.sub.0 magnet configured to produce a B.sub.0 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.