Abstract: A magnet apparatus for a magnetic resonance imaging system, the magnet apparatus includes a vacuum vessel, a helium vessel disposed within the vacuum vessel and a thermal shield disposed between the vacuum vessel and the helium vessel. A set of passive compensation coils are disposed within the vacuum vessel or the helium vessel and used to compensate for magnetic field distortion caused by mechanical vibrations within the magnet apparatus.

Abstract: A magnet apparatus for a magnetic resonance imaging system, the magnet apparatus includes a cylindrical vacuum vessel, a closed loop cooling system disposed within the vacuum vessel and a cylindrical thermal shield disposed between the vacuum vessel and the closed loop cooling system. A set of passive compensation coils are disposed within the vacuum vessel and used to compensate for magnetic field distortion caused by mechanical vibrations within the magnet apparatus.

Abstract: A gradient coil apparatus for a magnetic resonance imaging (MRI) system includes an inner gradient coil assembly comprising at least one inner gradient coil and an outer gradient coil assembly comprising at least one outer gradient coil. At least one gradient coil interconnect is coupled to the inner gradient coil and the outer gradient coil. The gradient coil interconnect includes a wire assembly comprising a plurality of conductors. The wire assembly has a first end electrically coupled to the outer gradient coil assembly and a second end electrically coupled to the inner gradient coil. The gradient coil interconnect also includes a reinforcement material disposed around a portion of the wire assembly.

Abstract: A gradient coil apparatus for a magnetic resonance imaging (MRI) system includes an inner gradient coil assembly and an outer gradient coil assembly disposed around the inner gradient coil assembly. The outer gradient coil assembly has an outer surface, a first end and a second end. The gradient coil apparatus also includes a force balancing apparatus disposed around the outer surface of the outer gradient coil assembly. In one embodiment, the force balancing apparatus includes an active force balancing coil disposed around the outer surface of the outer gradient coil assembly. In another embodiment, the force balancing apparatus includes a first passive conducting strip disposed around the first end of the outer gradient coil assembly and a second passive conducting strip disposed around the second end of the outer gradient coil assembly.

Abstract: A magnet apparatus for a magnetic resonance imaging system, the magnet apparatus includes a cylindrical vacuum vessel, a closed loop cooling system disposed within the vacuum vessel and a cylindrical thermal shield disposed between the vacuum vessel and the closed loop cooling system. A set of passive compensation coils are disposed within the vacuum vessel and used to compensate for magnetic field distortion caused by mechanical vibrations within the magnet apparatus.

Abstract: A gradient coil apparatus for a magnetic resonance imaging (MRI) system includes an inner gradient coil assembly and an outer gradient coil assembly disposed around the inner gradient coil assembly. The outer gradient coil assembly has an outer surface, a first end and a second end. The gradient coil apparatus also includes a force balancing apparatus disposed around the outer surface of the outer gradient coil assembly. In one embodiment, the force balancing apparatus includes an active force balancing coil disposed around the outer surface of the outer gradient coil assembly. In another embodiment, the force balancing apparatus includes a first passive conducting strip disposed around the first end of the outer gradient coil assembly and a second passive conducting strip disposed around the second end of the outer gradient coil assembly.

Abstract: A gradient coil apparatus for a magnetic resonance imaging (MRI) system includes an inner gradient coil assembly comprising at least one inner gradient coil and an outer gradient coil assembly comprising at least one outer gradient coil. At least one gradient coil interconnect is coupled to the inner gradient coil and the outer gradient coil. The gradient coil interconnect includes a wire assembly comprising a plurality of conductors. The wire assembly has a first end electrically coupled to the outer gradient coil assembly and a second end electrically coupled to the inner gradient coil. The gradient coil interconnect also includes a reinforcement material disposed around a portion of the wire assembly.

Abstract: The present invention provides an apparatus for reducing acoustic noise in a magnetic resonance imaging device including passive shielding located outside the actively shielded gradient winding elements in order to reduce the magnitude of fields that spread outside the gradient coil assembly in unwanted directions and interact with the magnet cryostat or other metallic magnet parts, inducing eddy currents that cause consequent acoustic noise. The passive shielding elements are conducting layers located on the outer radius of the cylindrical gradient coil assembly in a cylindrical magnet system, conducting layers located at the ends of the gradient coil assembly in a cylindrical magnet system, and conducting layers located inside the actively shielded gradient winding inner elements in a cylindrical magnet system. The passive shielding could also be located on separate structures that are vibrationally isolated from the magnet cryostat.

Abstract: The present invention provides an apparatus for reducing acoustic noise in a magnetic resonance imaging device including passive shielding located outside the actively shielded gradient winding elements in order to reduce the magnitude of fields that spread outside the gradient coil assembly in unwanted directions and interact with the magnet cryostat or other metallic magnet parts, inducing eddy currents that cause consequent acoustic noise. The passive shielding elements are conducting layers located on the outer radius of the cylindrical gradient coil assembly in a cylindrical magnet system, conducting layers located at the ends of the gradient coil assembly in a cylindrical magnet system, and conducting layers located inside the actively shielded gradient winding inner elements in a cylindrical magnet system. The passive shielding could also be located on separate structures that are vibrationally isolated from the magnet cryostat.

Abstract: The present invention provides an apparatus for reducing acoustic noise in a magnetic resonance imaging device including passive shielding located outside the actively shielded gradient winding elements in order to reduce the magnitude of fields that spread outside the gradient coil assembly in unwanted directions and interact with the magnet cryostat or other metallic magnet parts, inducing eddy currents that cause consequent acoustic noise. The passive shielding elements are conducting layers located on the outer radius of the cylindrical gradient coil assembly in a cylindrical magnet system, conducting layers located at the ends of the gradient coil assembly in a cylindrical magnet system, and conducting layers located inside the actively shielded gradient winding inner elements in a cylindrical magnet system. The passive shielding could also be located on separate structures that are vibrationally isolated from the magnet cryostat.