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：US20240230803A1

公开(公告)日：2024-07-11

申请号：US18544785

申请日：2023-12-19

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Yoshitomo SAKAKURA

IPC: G01R33/341

CPC classification number: G01R33/341

Abstract: A static field magnet includes at least one loop coil pair including: a first loop coil to be supplied with an electric current in a first direction; and a second loop coil to be supplied with an electric current in a second direction, wherein: the first and second loop coils are arranged such that a first coil plane surrounded by a first loop forming the first loop coil and a second coil plane surrounded by a second loop forming the second loop coil are arranged along a specific direction in a specific plane without overlapping each other; the loop coil pair generates a static magnetic field parallel to the specific direction; and each of the first and second loop coils is formed such that a side along its major axis direction has a concave portion curved toward coil interior and toward its minor axis direction.

公开(公告)号：US20190257901A1

公开(公告)日：2019-08-22

申请号：US16277068

申请日：2019-02-15

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Hidekazu TANAKA ,  Takuma KAWAI ,  Yoshitomo SAKAKURA ,  Motohisa YOKOI

IPC: G01R33/385 ,  G01R33/421 ,  H01F6/06

Abstract: A gradient coil according to an embodiment is configured to generate gradient magnetic fields along a plurality of axes in an imaging space in which a subject is imaged. The gradient coil includes a coil corresponding to at least one of the plurality of axes, wherein an electrically-conductive member of the coil is formed so as to be partitioned in a thickness direction by a plurality of electrically-insulative layers.

公开(公告)号：US20190064291A1

公开(公告)日：2019-02-28

申请号：US16108889

申请日：2018-08-22

Applicant: Canon Medical Systems Corporation

Inventor： Taketo KAWAKAMI ,  Yoshitomo SAKAKURA ,  Hidekazu TANAKA ,  Takahiro ISHIHARA

IPC: G01R33/385 ,  G01R33/54

Abstract: A magnetic resonance imaging apparatus according to an embodiment is a magnetic resonance imaging apparatus including a gradient coil unit configured to generate a gradient magnetic field in an imaging space in which a subject is placed. The gradient coil unit includes a cooling layer configured to cool the gradient coil. The cooling layer includes a first cooling pipe configured to cool the gradient coil entirely and a second cooling pipe configured to locally cool the gradient coil.

公开(公告)号：US20230375648A1

公开(公告)日：2023-11-23

申请号：US18316639

申请日：2023-05-12

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Yoshitomo SAKAKURA

IPC: G01R33/38

CPC classification number: G01R33/38

Abstract: In one embodiment, a static field magnet to be used for MRI includes at least one loop coil pair including: a first loop coil to be supplied with an electric current in a first direction; and a second loop coil to be supplied with an electric current in a second direction opposite to the first direction, wherein: the first and second loop coils are arranged such that a first coil plane and a second coil plane are along a primary direction without overlapping each other, the primary direction being included in a primary plane, the first coil plane being a planar area surrounded by a first loop that forms the first loop coil, the second coil plane being a planar area surrounded by a second loop that forms the second loop coil; and the loop coil pair is configured to generate a static magnetic field parallel to the primary direction.

公开(公告)号：US20200174088A1

公开(公告)日：2020-06-04

申请号：US16693448

申请日：2019-11-25

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Yoshitomo SAKAKURA ,  Hidekazu Tanaka

IPC: G01R33/385 ,  G01R33/58 ,  G01R33/565

Abstract: In one embodiment, an MRI apparatus includes: a scanner that is provided with at least an RF coil and a gradient coil and is configured to acquire a magnetic resonance (MR) signal emitted from an object in response to applications of an RF pulse outputted from the RF coil and a gradient magnetic field generated by the gradient coli; and processing circuitry configured to reconstruct a diagnostic image of the object based on the MR signal, generate distortion correction data for correcting a non-linear characteristic of the gradient magnetic field to a linear characteristic that is defined by gradient magnetic field strength at a correction position away from a magnetic field center of the gradient coil and distance from the magnetic field center to the correction position, and correct the diagnostic image by using the distortion correction data.