公开(公告)号：US20230397835A1

公开(公告)日：2023-12-14

申请号：US18318190

申请日：2023-05-16

Applicant: CANON MEDICAL SYSTEMS CORPORATION

Inventor： Takahiro TAMURA ,  Mitsuhiro BEKKU

IPC: A61B5/055 ,  G16H30/40 ,  G06T7/00

CPC classification number: A61B5/055 ,  G16H30/40 ,  G06T7/0002 ,  A61B5/0033

Abstract: A MRI apparatus according to an embodiment includes processing circuitry. The processing circuitry obtains MR data acquired by implementing an IR method under a condition where a phase difference in a complex signal related to observed elements is equal to π, due to a difference in longitudinal magnetization relaxation time between the observed elements; generates phase data on the basis of the MR data; multiplies a phase angle in the phase data by 2n; unfolds the phase of phase data having the phase angle multiplied by 2n; multiplies the phase angle in the unfolded phase data by 1/(2n); generates a phase correction map used for correcting a phase with respect to the complex signal, by applying a complex conjugate to phase data having the phase angle multiplied by 1/(2n); and performs a phase correction on the MR data by using the phase correction map.

公开(公告)号：US20180284212A1

公开(公告)日：2018-10-04

申请号：US15940188

申请日：2018-03-29

Applicant: Canon Medical Systems Corporation

Inventor： Daiki TAMADA ,  Takahiro TAMURA

IPC: G01R33/565 ,  G01R33/48

CPC classification number: G01R33/56572 ,  G01R33/4824

Abstract: According to one embodiment, an MRI apparatus includes sequence control circuitry that performs first scanning and second scanning along mutually opposite radial directions in k-space, crossing over a k-space origin, and performs third scanning, and processing circuitry that generates first and second projection images by respectively applying a one-dimensional Fourier transform for the directions to first and second MR signals respectively acquired by the first and second scanning, determines correction coefficients related to transient response characteristics of a readout gradient magnetic field by a calculating process to reduce a difference between the first and second projection images, and generates a corrected image in which the transient response characteristics are corrected using the correction coefficients and MR signals acquired by the third scanning.

公开(公告)号：US20190113588A1

公开(公告)日：2019-04-18

申请号：US16147954

申请日：2018-10-01

Applicant: Canon Medical Systems Corporation

Inventor： Takahiro TAMURA ,  Hiroshi TAKAI ,  Nobuyuki KONUMA

IPC: G01R33/483 ,  G01R33/54 ,  G01R33/56

Abstract: A magnetic resonance imaging apparatus according to the present embodiment includes sequence control circuitry. The sequence control circuitry collect first MR data in a first cardiac cycle by excitation of a first region including a first slice, and collects reference data used for phase correction of second MR data on a second slice not included in the first region before and after the collection of the first MR data in the first cardiac cycle.