Mitsubishi Denki Kabushiki Kaisha

Other

Hitachi Medical Corporation

Shigenori Kuroda

Hajime Tanabe

Hirotaka Takeshima

Naoji Yoshida

Hiroshi Tazaki

Hajime Kawano

Takeshi Yatsuo

Moriaki Takechi

Takao Hommei

Kazuki Moritsu

Takao Honmei

Tsugio Watanabe

A superconductive magnet device comprises a pair of oppositely disposed superconductive bodies in which annular superconductive coils are accommodated, and fine chip-shaped ferromagnetic shims disposed on a surface of the pair of superconductive magnet bodies so as to improve uniformity of magnetic field in a uniform magnetic field in a uniform magnetic field space generated in the proximity of the center between the superconductive magnet bodies, wherein ring-shaped ferromagnetic shims are disposed concentrically with the center of annular superconductive coils on the surface of the superconductive magnet bodies.

Superconductive magnet device

An open-type magnet device for MRI includes a pair of upper and lower magnet assemblies, and shims are provided on opposite sides of their cooling containers and/or in holes passing through central portions of the cooling containers so as to facilitate providing a highly homogeneous static magnetic field.

Open-type magnet device for MRI

A superconductive magnet device comprises a pair of oppositely disposed superconductive bodies in which annular superconductive coils are accommodated, and fine chip-shaped ferromagnetic shims disposed on a surface of the pair of superconductive magnet bodies so as to improve uniformity of magnetic field in a uniform magnetic field space generated in the proximity of the center between the superconductive magnet bodies, wherein ring-shaped ferromagnetic shims are disposed concentrically with the center of annular superconductive coils on the surface of the superconductive magnet bodies.

A superconducting magnet apparatus. By forming one or more holes in each of platelike ferromagnetic substances forming a magnetic shield for focusing the magnetic flux generated by superconducting coils, the flow of lines of magnetic flux is adjusted. Thereby, a static magnetic field in a measurement space is corrected. By disposing coupling tubes for supporting two cooling vessels housing superconducting coils on the rear side with respect to a central axis (Z axis) of the measurement space of the vertical direction, access to the subject is facilitated. In addition, the magnetic shield has an opening portion wider than the superconducting magnet on its side face. After the magnetic shield has been assembled, the superconducting magnet can be inserted from the opening portion.

Superconducting magnetic apparatus

Superconducting magnetic device

A magnetic field compensating apparatus having a plurality of compensating units comprising a plurality of serial coils each of which is disposed concentrically along the main magnetic field and symmetrically with regard to a plane perpendicular to the main magnetic field and a plurality of power sources which separately supply currents to these compensating units, and made in such a manner that a plurality of error magnetic field components are generated by each of the compensating units, a compensating magnetic field is obtained by the whole of a plurality of the compensating units, and each of the currents supplied to the compensating units is decided in accordance with a constitution of a corresponding compensating unit.

Magnetic field compensating apparatus

An electromagnet has a magnetic shield whose end plate is formed with an asymmetrical side hole 10 in addition to a center opening 6. The thickness of portion 11 of the end plate which covers an area defined by a deviation angle of not more than 180.degree. with a center line passing through a center of the side hole is made larger than the remaining portion of the end plate.

Growing community of inventors

Tokyo, Japan

Shigenori Kuroda