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公开(公告)号：US20240241202A1
公开(公告)日：2024-07-18
申请号：US18391962
申请日：2023-12-21
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Sotaro TAKI , Sadanori TOMIHA , Masao YUI
IPC: G01R33/56 , G01R33/48 , G01R33/565
CPC classification number: G01R33/5601 , G01R33/4804 , G01R33/56563
Abstract: An MRI apparatus according to one embodiment includes processing circuitry that obtains information about a contrast agent containing substances with different chemical shifts, and determines, based on the information, a frequency band related to decrease in a MR signal due to the chemical shifts; and sequence control circuitry that acquires, before contrast enhancement using the contrast agent, a first MR signal group in the frequency band by CEST imaging under different saturation pulse conditions, and acquires, after contrast enhancement using the contrast agent, a second MR signal group in the frequency band by CEST imaging under different saturation pulse conditions. The processing circuitry calculates a difference between a first Z-spectrum generated based on the first MR signal group and a second Z-spectrum generated based on the second MR signal group, and detects, from the difference, peaks indicating the decrease in the MR signal due to the chemical shifts of the substances.
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公开(公告)号：US20230014564A1
公开(公告)日：2023-01-19
申请号：US17808405
申请日：2022-06-23
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Masanori OZAKI , Masao YUI
IPC: G01R33/561 , G01R33/44
Abstract: An MRI apparatus according to an embodiment includes sequence controlling circuitry, in a first transition period, repeating application of a first MT pulse and acquisition of a first MR signal to a first frequency region being a part of a k-space; in the first steady state, repeating application of the first MT pulse and acquisition of a second MR signal to a second frequency region of the k-space, frequency in second frequency region being lower than frequency in the first frequency region; and in a second transition period, repeating application of a second MT pulse and acquisition of a third MR signal to a third frequency region being another part of the k-space, frequency in the third frequency region being higher than the frequency in the second frequency region, and processing circuitry generating one MR image on basis of the first, second, and third MR signal.
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公开(公告)号：US20230043460A1
公开(公告)日：2023-02-09
申请号：US17870996
申请日：2022-07-22
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Sotaro TAKI , Masao YUI , Sadanori TOMIHA
Abstract: A magnetic resonance imaging apparatus includes sequence control circuitry and processing circuitry. In CEST imaging the sequence control circuitry performs a first sequence and a second sequence under different saturation pulse conditions. The first sequence is for acquiring first magnetic resonance signals corresponding to a first frequency region of a k-space and second magnetic resonance signals corresponding to a second frequency region of the k-space. The second sequence is for acquiring third magnetic resonance signals corresponding to at least the first frequency region. The processing circuitry assigns the third magnetic resonance signals and the second magnetic resonance signals to a single k-space generated for the second sequence. Frequency including the first frequency region is lower than frequency including the second frequency region.
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公开(公告)号：US20220397626A1
公开(公告)日：2022-12-15
申请号：US17804220
申请日：2022-05-26
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Masao YUI , Aina IKEZAKI
IPC: G01R33/561 , G01R33/563 , G01R33/54 , G01R33/50
Abstract: In one embodiment, an MRI apparatus includes: processing circuitry configured to: set a first pulse sequence and a second pulse sequence, wherein, in the first pulse sequence, a first gradient pulse is applied between two adjacent refocusing pulses, and, in the second pulse sequence, a second gradient pulse being different in pulse shape from the first gradient pulse is applied between two adjacent refocusing pulses, wherein: the scanner is configured to acquire first signals and second signals; and the processing circuitry is configured to generate at least one first image and at least one second image; and calculate a T2 value of a body fluid of the object from the at least one first image and the at least one second image in such a manner that influence of movement including diffusion of the body fluid is removed.
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公开(公告)号：US20200174092A1
公开(公告)日：2020-06-04
申请号：US16699345
申请日：2019-11-29
Applicant: Shinya Yamada , Keio University , CANON MEDICAL SYSTEMS CORPORATION
Inventor： Koichi OSHIO , Shinya YAMADA , Masao YUI , Seiko SAKURABA
IPC: G01R33/561 , G01R33/54
Abstract: A magnetic resonance imaging method according to an embodiment includes performing a balanced SSFP sequence, repeatedly applies an excitation RF pulse to a subject at intervals of a repetition time and applies gradient magnetic field pulses balanced such that a time integral becomes zero within each interval of the repetition time, while further applying a spin labeling gradient magnetic field for generating one or more continuous spin labels within each interval of the repetition time.
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公开(公告)号：US20200069185A1
公开(公告)日：2020-03-05
申请号：US16676818
申请日：2019-11-07
Applicant: Canon Medical Systems Corporation
Inventor： Hitoshi YAMAGATA , Masao YUI
Abstract: A magnetic resonance imaging apparatus according to an embodiment includes processing circuitry. The processing circuitry is configured to specify a search start position of a matrix representing inter-regional connectivity between a plurality of regions in a brain based on a result of an analysis on an image of a subject and an attention degree set to each of the regions. The processing circuitry is configured to search the matrix using the search start position.
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公开(公告)号：US20230255507A1
公开(公告)日：2023-08-17
申请号：US18165961
申请日：2023-02-08
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Ryohei TAKAYANAGI , Takaya MORI , Kagami FUJITA , Akihiro TAGUCHI , Masao YUI
Abstract: A magnetic resonance imaging apparatus includes sequence controlling circuitry configured: to obtain, during a time period after excitation of a first nuclide in a hyperpolarized state but no later than before obtainment of a first magnetic resonance signal from the first nuclide, a second magnetic resonance signal from a second nuclide that is different from the first nuclide and is in a non-hyperpolarized state, by exciting the second nuclide; and to control each of gradient magnetic field waveforms so as to cause both a first sum indicating a sum of application amounts of a gradient magnetic field related to the excitation of the second nuclide and a second sum indicating a sum of application amounts of a gradient magnetic field related to the obtainment of the second magnetic resonance signal to be close to zero, no later than before the obtainment of the first magnetic resonance signal.
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公开(公告)号：US20220236354A1
公开(公告)日：2022-07-28
申请号：US17643536
申请日：2021-12-09
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Yoshimori KASSAI , Masao YUI
Abstract: A magnetic resonance imaging apparatus according to an embodiment includes processing circuitry. The processing circuitry acquires an echo signal generated for each of intervals of repetition time by applying an excitation pulse to a subject at the intervals of repetition time, and acquires data of a plurality of trajectories set for a k-space using the echo signals. The processing circuitry acquires a plurality of echo signals by setting echo time to lengths different between a plurality of periods of repetition time and acquires data of the same trajectory using the echo signals, and the echo time serves as time from application of the excitation pulse to generation of the echo signal.
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公开(公告)号：US20210132166A1
公开(公告)日：2021-05-06
申请号：US17089081
申请日：2020-11-04
Applicant: CANON MEDICAL SYSTEMS CORPORATION
Inventor： Sadanori TOMIHA , Masao YUI
Abstract: A magnetic resonance imaging apparatus according to an embodiment includes a static magnetic field generator, a transmit/receive system, and an acquiring means. The static magnetic field generator is configured to apply a second static magnetic field in addition to a first static magnetic field serving as a reference. The transmit/receive system is configured to perform transmitting and receiving at a single frequency. The processing circuitry is configured to acquire a magnetic resonance signal by employing the transmit/receive system. The transmit/receive system is configured to perform transmitting and receiving at a resonance frequency of a hydrogen nucleus in a state in which the first static magnetic field is applied and is configured to perform transmitting and receiving at a resonance frequency of a nuclide different from the hydrogen nucleus in a state in which the second static magnetic field is applied in addition to the first static magnetic field.
