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：US20230324480A1

公开(公告)日：2023-10-12

申请号：US18328623

申请日：2023-06-02

Applicant: Canon Medical Systems Corporation

Inventor： Hitoshi KANAZAWA ,  Seiji NOZAKI ,  Takehiro SHIBUYA

IPC: H01F6/04 ,  G01R33/3815 ,  H01F6/02 ,  G01R33/54 ,  G01R33/38

CPC classification number: G01R33/3815 ,  G01R33/3804 ,  G01R33/543 ,  H01F6/02 ,  H01F6/04

Abstract: According to one embodiment, a magnetic resonance imaging apparatus includes processing circuitry. The processing circuitry is configured to calculate an allowable amount of heat input to a superconducting magnet, the allowable amount being allocated to each of a plurality of imagings scheduled during a target period. The processing circuitry is configured to determine an imaging condition based on the allowable amount in the each of the plurality of imagings.

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：US20220146611A1

公开(公告)日：2022-05-12

申请号：US17519944

申请日：2021-11-05

Applicant: Canon Medical Systems Corporation

Inventor： Kazuto NAKABAYASHI ,  Takehiro SHIBUYA

IPC: G01R33/3815 ,  H01F6/04 ,  H01F6/02

Abstract: According to one embodiment, a MRI apparatus determines a first time during which a subsidiary power supply is capable of supplying power to a cooling device based on a capacity of the subsidiary power supply when power outage of a main power supply occurs, and determines a second time needed to demagnetize a superconducting magnet based on an excitation current of the superconducting magnet and a temperature of the superconducting magnet. The MRI apparatus determines starts ramp-down of the superconducting magnet after a third time based on the first time and the second time has elapsed from initiation of power outage of the main power supply.

公开(公告)号：US20220146607A1

公开(公告)日：2022-05-12

申请号：US17519962

申请日：2021-11-05

Applicant: Canon Medical Systems Corporation

Inventor： Hitoshi KANAZAWA ,  Seiji NOZAKI ,  Takehiro SHIBUYA

IPC: G01R33/38 ,  G01R33/3815

Abstract: According to one embodiment, a magnetic resonance imaging apparatus includes processing circuitry. The processing circuitry calculates a limit imaging condition based on one or more imaging parameters for determining an imaging condition, the limit imaging condition being an allowable limit relating to heat input to a superconducting magnet. The processing circuitry limits an input range of an imaging parameter input by an operator based on the limit imaging condition.

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：US20230251336A1

公开(公告)日：2023-08-10

申请号：US18305209

申请日：2023-04-21

Applicant: Canon Medical Systems Corporation

Inventor： Kazuto NAKABAYASHI ,  Takehiro SHIBUYA

IPC: G01R33/3815 ,  H01F6/02 ,  H01F6/04

CPC classification number: G01R33/3815 ,  H01F6/02 ,  H01F6/04

Abstract: According to one embodiment, a MRI apparatus determines a first time during which a subsidiary power supply is capable of supplying power to a cooling device based on a capacity of the subsidiary power supply when power outage of a main power supply occurs, and determines a second time needed to demagnetize a superconducting magnet based on an excitation current of the superconducting magnet and a temperature of the superconducting magnet. The MRI apparatus determines starts ramp-down of the superconducting magnet after a third time based on the first time and the second time has elapsed from initiation of power outage of the main power supply.

公开(公告)号：US20220146610A1

公开(公告)日：2022-05-12

申请号：US17453679

申请日：2021-11-05

Applicant: Canon Medical Systems Corporation

Inventor： Hitoshi KANAZAWA ,  Seiji NOZAKI ,  Takehiro SHIBUYA

IPC: G01R33/3815 ,  G01R33/38 ,  G01R33/54 ,  H01F6/02 ,  H01F6/04

Abstract: According to one embodiment, a magnetic resonance imaging apparatus includes processing circuitry. The processing circuitry is configured to calculate an allowable amount of heat input to a superconducting magnet, the allowable amount being allocated to each of a plurality of imagings scheduled during a target period. The processing circuitry is configured to determine an imaging condition based on the allowable amount in the each of the plurality of imagings.

公开(公告)号：US20250060436A1

公开(公告)日：2025-02-20

申请号：US18797686

申请日：2024-08-08

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Katsutoshi MIZUNO ,  Takehiro SHIBUYA

IPC: G01R33/3815 ,  G01R33/38

Abstract: A superconducting magnet device of an embodiment includes a vacuum vessel, a superconducting coil, and an insulating load support. The insulating load support supports the superconducting coil through the thermal deformation cancellation 5 mechanism that generates a second deformation amount in a direction in which a first deformation amount applied from the superconducting coil to the insulating load support is canceled out due to thermal deformation occurring in the superconducting coil when the inside of the vacuum vessel is cooled to an extremely low temperature. The thermal deformation cancellation mechanism includes a thermal deformation member. The 10 thermal deformation member includes at least a material having a second coefficient of thermal expansion determined based on a first coefficient of thermal expansion of a material forming the superconducting coil, and generates the second deformation amount by thermally deforming in the same environment as the superconducting coil.