Abstract: A magnetic resonance imaging system has a superconducting magnet housed within a cryostat, a cryogenic refrigerator that cools within the cryostat, a helium compressor that supplies compressed helium to the cryogenic refrigerator and to receive a return flow of compressed helium from the refrigerator, and a magnet supervisory system controlling operation of the magnet resonance imaging system. An apparatus is provided for controlling the speed and/or timing of operation of the helium compressor in accordance with predefined algorithms in response to system state data.

Abstract: A magnetic resonance imaging system has a superconducting magnet contained within a cryostat, the cryostat being cooled by a cooling system that includes a healing and compressor, a refrigeration device and a local supervisory system. The helium compressor provides compressed helium to the refrigeration device, and the local supervisory system controls operation of the refrigeration device. The helium compressor is in communication with the local supervisory system, and also is able to communicate, independently of the local supervisory system, with a remote service provider.

Abstract: A suspension assembly for mechanically retaining a first article by bracing it against a distant second article, includes a tensile rod that extends between first and second articles. At least one first surface is mechanically linked to the tensile rod, and at least one second surface mechanically linked to the first article. The first surface and said second surface are braced against one another by tension in the tensile rod, and have at least three separate points of contact between them. At least one of the first and second surfaces is non-planar, and at least one of the points of contact is provided by a part of the surface which is convex and non-planar.

Abstract: A superconducting annular electromagnet for MRI purposes includes an annular winding within which a generally cylindrical space is provided. The winding includes at least one pair of annular coils, each having an outer cylindrical surface which is suitably formed to define a feature which facilitates fixing.

Abstract: A superconducting annular electro-magnet for MRI purposes includes an annular winding within which a generally cylindrical space is provided. The winding adjacent each end of the space is formed with a chamfer to provide flaring at each end of the space.

Abstract: An electromagnet for use in an MRI apparatus includes an annular vessel inside of which annular windings, energizable to produce a magnetic field, are contained together with cold iron components. The iron components are mechanically anchored with respect to the windings. A pair of iron rings is positioned so that one ring is provided at each end of the magnet in close proximity to the annular windings. The rings are formed so as to define a flared opening at each end of a cylindrical space within the magnet which, in use of the magnet for MRI purposes, is occupied by a patient.

Abstract: A superconducting electromagnet comprising an annular inner helium container vessel within which the windings of an annular magnet are contained, an outer annular vacuum chamber within which the said inner vessel is contained, and a generally annular hollow thermal shield arranged to enclose the inner vessel and disposed between the said vessel and the said chamber in spaced apart relationship so that the longitudinal axes of the said shield and the magnet are substantially co-extensive, an outer wall of the shield being defined by concentric generally cylindrical mutually spaced inner and outer thermal screens, which in combination define a double wall screen, the shield having a double wall only in a region concentric with the longitudinal axis of the magnet.

Abstract: A super-conducting electro-magnet for use in an MRI system comprising a helium vessel within which magnet windings are positioned, a vacuum chamber within which the helium vessel is contained, at least one thermal shield positioned between the helium vessel and the vacuum chamber, a service turret having a neck tube which is arranged to extend through the thermal shield within the vacuum chamber so as to communicate with the helium vessel for filling purposes, the thermal shield being thermally coupled to the service turret neck tube by means of a plurality of flexible connector strips fabricated from laminated conductive material which at one end are secured to the thermal shield and which at the other end thereof are secured to the service turret neck tube, sufficient strips being provided substantially to surround the service turret neck tube thereby to provide a substantially continuous thermally conductive junction between the service turret neck tube and the thermal shield.