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

IPC: G01R33/54 ,  G01R33/48

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.

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.

公开(公告)号：US20240036134A1

公开(公告)日：2024-02-01

申请号：US18347735

申请日：2023-07-06

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Sotaro TAKI

IPC: G01R33/48 ,  A61B5/055 ,  G01R33/56

CPC classification number: G01R33/4804 ,  A61B5/055 ,  G01R33/5601

Abstract: A pH calculating apparatus according to an embodiment includes processing circuitry that obtains a Z spectrum generated from a CEST imaging process by using, for a subject, a contrast agent containing types of substances having mutually-different responsiveness to pH during chemical shift imaging and including fall points of signal values corresponding to the types of substances; obtains information related to the subject; calculates a pH dependent value by using MR signal values corresponding to the fall points of the signal values; selects a standard curve indicating a pH value corresponding to the pH dependent value in accordance with the information, from among standard curves prepared in advance in accordance with the information; and determines a pH value based on the selected standard curve and the pH dependent value.