Abstract: A low eddy current cryogen circuit for superconducting magnets including at least a first cooling coil made of an electrically conducting material and having at least one electrical isolator incorporated in the first cooling coil. The electrical isolator is located to inhibit induced eddy current loops due to inductive coupling of the first cooling coil with eddy current inducing field sources.

Abstract: Systems, methods and apparatus are provided through which in some embodiments a magnetic resonance imaging (MRI) system includes one or more magnetic shield coils positioned asymmetrically in the casing and also positioned in close proximity to one of two apertures of an inner bore of the MRI system. In those embodiments, the position of the one or more magnetic shield coils provides an asymmetric magnetic stray field during operation of the MRI system, which in turn allows operation of electronic medical diagnostic equipment or electronic medical monitoring equipment in close proximity to the MRI.

Abstract: A magnetic resonance imaging (MRI) magnet having a first section and a second section is disclosed. The first section has a first housing, and a first set of magnet coils arranged about a common axis that include coils proximate the common axis. The second section has a second housing, and a second set of magnet coils arranged about the common axis where the coils are radially displaced from the common axis. The second section is connected to but axially displaced a distance “d” from the first section.

Abstract: A system and method for decreasing partial discharge between adjacent conductive plates includes suspending a plurality of particles in the space between adjacent plates of a magnetic coil. The plurality of particles are generally uniformly dispersed in the space and allow for increased partial discharge inception voltages. Such a construction allows the coil to operate at elevated driving voltages with reduced partial discharge between adjacent plates.

Abstract: Systems, methods and apparatus are provided through which in some embodiments a magnetic resonance imaging (MRI) system includes an asymmetrical magnet to generate an asymmetrical stray field that is particularly well suited to imaging limbs. In some other embodiments, a MRI system includes a conically-shaped casing that allows a patient to more readily access a field-of-view (FOV) in the interior of the MRI system during imaging of limbs. In some embodiments, a MRI system includes a stepped inner bore that has a stepped shape that focuses the FOV in an inner bore of the MRI system on a smaller area that is closer to where a patient accesses the FOV in the MRI that is particularly well suited to imaging a limb in the FOV.

Abstract: An integrated electronic system housing and magnet structure (12) for an imaging system (10) includes a housing (40) and a radio frequency shield (46). The housing (40) is coupled to the magnet structure (13) and contains imaging system support electronics (42). The radio frequency shield (46) is coupled to the housing (40) and prevents radio frequency interference of a radio frequency receiver coil (30) from the imaging system support electronics (42).

Abstract: The disclosed apparatus relates to a gradient coil assembly for a magnetic resonance imaging system. The gradient coil assembly comprises: at least two coils. The coils comprise: at least one conductor mechanically bonded via a nonconducting substrate. The bonding surface of the at least one conductor has been subjected to a surface treatment to improve the mechanical bonding properties of the bonding surface. The disclosed apparatus also relates to a magnetic imaging system. The magnetic imaging system comprises: a system controller; a gradient amplifier unit in operable communication with the system controller; a magnetic assembly in operable communication with the gradient amplifier. The magnetic assembly comprises: a gradient coil assembly comprising at least two coils. The coils comprise: at least one conductor mechanically bonded via a nonconducting substrate.

Abstract: An open architecture platform superconducting magnet for international procedures with a shaped yoke assembly and associated magnet coil and with a patient support positioned above the magnet coil, and a magnetic field imaging volume which is conically shaped with a cross section which decreases in size remote from the coil.

Abstract: An open magnet has vertically aligned first and second assemblies each with at least one superconductive main coil. At least one support member is vertically aligned and attached to, the first and second assemblies. At least one cryocooler coldhead is aligned generally horizontally and has a housing which is attached to, and receives weight-bearing support from, one of the first and second assemblies.

Abstract: A method for shimming a magnetic resonance imaging magnet requiring higher magnetic field homogneity on a small imaging volume and by magnetic field measurements on a larger volume providing small measurement error and practical field strength measurements and utilizing the spherical harmonic coefficients of the measurements.

Abstract: An open magnetic resonance imaging (MRI) magnet having first and second spaced-apart superconductive coil assemblies each including a toroidal-shaped coil housing containing a superconductive main coil at least partially immersed in a cryogenic fluid such as liquid helium. A generally-non-permanently-magnetized ferromagnetic ring is associated with each coil assembly, being generally coaxially aligned with the associated coil assembly and being spaced radially inward and radially apart from the associated coil assembly's superconductive main coil. The ferromagnetic rings overcome the gross magnetic field distortions in the imaging volume of the superconductive main coils (created by the open space between the magnet's superconductive coil assemblies) to produce a magnetic field of high uniformity within the imaging volume.

Abstract: A correction coil current adjustment circuit for a superconducting magnet to selectively switch various coils in circuit with a power source to provide the desired superconducting current flow and magnetic field homogeneity for magnetic resonance imaging eliminating the need for some of the mechanical leads which extend from the exterior of the magnet to the interior of the cryogen vessel minimizing thermal leak paths and including simplified switching of the various main and correction magnet coils to provide the desired current flow. Inductive coupling from outside the magnet to induce correction coil current flow eliminates additional mechanical leads.

Abstract: In the installation of a superconducting magnet for magnetic resonance imaging at a preselected position in a mobile van, preselected curvilinear magnetic segments are applied to preselected locations on the exterior of the magnet to counteract magnet inhomogeneities in the imaging bore which would otherwise occur because of magnetic material in the van structure.

Abstract: A passively shimmed open architecture magnetic resonance imaging magnet utilizing separated superconducting coil assemblies with open space between including means to obtain a uniform magnetic field in the open space by shaped ferromagnetic bands in the bore of the magnets, the shaping including an axial notch and circumferential holes for attaching passive shims.

Abstract: A superconductive-magnet electrical circuit includes a superconductive-coil assemblage having first, second, third, and fourth coil portions sequentially coupled together in series. A bipolar current-bypass electrical-circuit element (such as a pair of diodes opposingly coupled together in parallel) has:an impedance less than generally one-thousandth that of the coil portions; a first terminal coupled in parallel with the first and second coil portions; and a second terminal coupled in parallel with the third and fourth coil portions. A localized quench in one coil portion is quickly shared with the other coil portions to reduce damage from the quench. A resistor has a lead coupled in parallel with the second and third coil portions to limit quench voltages.