公开(公告)号：US20240077558A1

公开(公告)日：2024-03-07

申请号：US18457490

申请日：2023-08-29

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Takehiro SHIBUYA ,  Hiromi KAWAMOTO ,  Sadanori TOMIHA

IPC: G01R33/3815 ,  G01R33/385

CPC classification number: G01R33/3815 ,  G01R33/385

Abstract: A static magnetic field magnet according to any of embodiments includes: a superconducting coil generating a static magnetic field; and a radiation shield surrounding the superconducting coil. In the static magnetic field magnet, at least a surface on a gradient coil side of the radiation shield includes a peripheral portion that forms multiple concavity and/or convexity. Further, In the static magnetic field magnet, a shape of a cross-section perpendicular to a depth direction of each of the multiple concavity and/or convexity formed by the peripheral portion is polygonal or circular. It is preferable that the peripheral portion is configured to form the multiple concavity and/or convexity in a straight line.

公开(公告)号：US20240077559A1

公开(公告)日：2024-03-07

申请号：US18459584

申请日：2023-09-01

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Takehiro SHIBUYA ,  Hiromi KAWAMOTO ,  Sadanori TOMIHA

IPC: G01R33/3815 ,  G01R33/385

CPC classification number: G01R33/3815 ,  G01R33/3856

Abstract: A static magnetic field magnet according to any of embodiments includes: a vacuum vessel; a radiation shield provided inside the vacuum vessel; a superconducting coil provided inside the radiation shield, the superconducting coil generating a static magnetic field; and a winding frame supporting the superconducting coil and including a heat-generation suppression shield having a surface layer on a gradient coil side and an inner layer on the superconducting coil side. In the static magnetic field magnet, the surface layer and the inner layer are structurally or functionally separated from each other, the surface layer is configured as a layer where an eddy current generated in the winding frame flows, and the inner layer is configured as a layer where an eddy current does not almost flow.

公开(公告)号：US20240077556A1

公开(公告)日：2024-03-07

申请号：US18453372

申请日：2023-08-22

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Takehiro SHIBUYA ,  Hiromi KAWAMOTO ,  Sadanori TOMIHA ,  Misaki HATTAHA

IPC: G01R33/3815 ,  G01R33/38 ,  G01R33/54

CPC classification number: G01R33/3815 ,  G01R33/3804 ,  G01R33/543

Abstract: In one embodiment, an MRI apparatus includes: a static magnet provided with a superconducting coil and configured to generate a static magnetic field having static magnetic field distribution in an open space outside the superconducting coil; control circuitry configured to adjust the static magnetic field distribution; and a reconstruction processing circuit configured to generate a magnetic resonance image on the basis of magnetic resonance signals emitted from an object that is at least partially placed in the open space outside the superconducting coil.

公开(公告)号：US20250060439A1

公开(公告)日：2025-02-20

申请号：US18800203

申请日：2024-08-12

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Takehiro SHIBUYA ,  Sadanori TOMIHA ,  Yoshitomo SAKAKURA ,  Hiromi KAWAMOTO ,  Yuuzo KAMIGUCHI ,  Michiru KAJIWARA

IPC: G01R33/421 ,  A61B5/055 ,  G01R33/34 ,  G01R33/3875

Abstract: An MRI system includes a static magnetic field magnet configured to determine an MR frequency for imaging and generate a first static magnetic field be applied to an object during imaging; a pre-polarizing magnet configured to polarize nuclear spin of the object prior to imaging of the object and generate a second static magnetic field, application of which is stopped during imaging of the object; at least one first shield configured to block a leakage magnetic field of the first static magnetic field, the first shield being provided in a region opposite to an imaging region of the object with respect to the static magnetic field magnet; and at least one second shield configured to block a leakage magnetic field of the second static magnetic field, the second shield being provided in a region opposite to the imaging region with respect to the pre-polarizing magnet.

公开(公告)号：US20250060435A1

公开(公告)日：2025-02-20

申请号：US18796780

申请日：2024-08-07

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Takehiro SHIBUYA ,  Hiromi KAWAMOTO

IPC: G01R33/3815 ,  G01R33/38 ,  G01R33/3875

Abstract: In one embodiment, a superconducting magnet includes: at least one primary superconducting coil configured to generate a primary magnetic field; at least one secondary superconducting coil configured to generate a secondary magnetic field in a direction opposite to a direction of the primary magnetic field; and a superconducting shim coil configured to surround part or all of an outer surface of at least one of the at least one primary superconducting coil and the at least one secondary superconducting coil and corrects distribution of a static magnetic field generated by both the at least one primary superconducting coil and the at least one secondary superconducting coil.

公开(公告)号：US20240077557A1

公开(公告)日：2024-03-07

申请号：US18455752

申请日：2023-08-25

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Takehiro SHIBUYA ,  Hiromi KAWAMOTO

IPC: G01R33/3815 ,  H01F6/06

CPC classification number: G01R33/3815 ,  H01F6/06

Abstract: In one embodiment, a superconducting magnet includes: at least one set of coil segment including a first coil segment formed of a superconducting wire through which an electric current flows in a forward direction, and a second coil segment formed of the superconducting wire through which an electric current flows in a direction opposite to the forward direction; and at least one intermediate wiring provided between the first coil segment and the second coil segment and configured to connect the first coil segment and the second coil segment without disconnection and change directions of electric currents such that that the electric current flows through the first coil segment in the forward direction and the electric current flows through the second coil segment in a direction opposite to the forward direction.

公开(公告)号：US20240077555A1

公开(公告)日：2024-03-07

申请号：US18451279

申请日：2023-08-17

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Takehiro SHIBUYA ,  Hiromi KAWAMOTO

IPC: G01R33/3815 ,  H01F6/00 ,  H01F6/02 ,  H01F6/06

CPC classification number: G01R33/3815 ,  H01F6/008 ,  H01F6/02 ,  H01F6/06

Abstract: In one embodiment, a superconducting magnet includes: at least one primary superconducting coil configured to generate a primary static magnetic field by a persistent current flowing during a persistent current mode; at least one secondary superconducting coil configured to generate a secondary static magnetic field different from the primary static magnetic field in response to external control; and a static-magnetic-field control switch configured to (i) supply the secondary superconducting coil with part of the persistent current to generate the secondary static magnetic field by being closed in response to the external control during the persistent current mode and (ii) stop energization of the secondary superconducting coil and generation of the secondary static magnetic field by being opened in response to the external control during the persistent current mode.