公开(公告)号：US12114967B2

公开(公告)日：2024-10-15

申请号：US18156161

申请日：2023-01-18

Applicant: GE PRECISION HEALTHCARE LLC

Inventor： Afis Ajala ,  Seung-Kyun Lee ,  Thomas Kwok-Fah Foo

IPC: A61B5/055 ,  G01R33/385 ,  G01R33/565 ,  G01R33/48

CPC classification number: A61B5/055 ,  G01R33/385 ,  G01R33/56581 ,  G01R33/4824

Abstract: A magnetic resonance (MR) system is provided. The MR system includes a gradient coil assembly and a concomitant field correction computing device. The at least one processor of the computing device is programmed to receive MR signals acquired with the MR system using a three-dimensional (3D) pulse sequence, wherein a kx dimension and a ky dimension in k-space are sampled along non-Cartesian trajectories. The at least one processor is further programmed to correct effects of concomitant fields generated by gradient fields applied by the gradient coil assembly by adjusting the MR signals with second-order concomitant phases accumulated from second-order concomitant fields, and reconstructing MR images based on the adjusted MR signals. The second-order concomitant phases vary as functions of time and spatial locations. The at least one processor is also programmed to output the MR images.

公开(公告)号：US20240237910A1

公开(公告)日：2024-07-18

申请号：US18156144

申请日：2023-01-18

Applicant: GE PRECISION HEALTHCARE LLC

Inventor： Seung-Kyun Lee ,  Afis Ajala ,  Thomas Kwok-Fah Foo

IPC: A61B5/055 ,  G01R33/385 ,  G01R33/565

CPC classification number: A61B5/055 ,  G01R33/385 ,  G01R33/56554 ,  G01R33/56581 ,  G01R33/389

Abstract: A magnetic resonance (MR) system for correcting concomitant field effects is provided. The MR system includes a gradient coil assembly including a plurality of gradient coils configured to apply at least one gradient field to a polarizing magnetic field of the MR system. The MR system also includes a second-order correction coil assembly including a first second-order correction coil configured to correct effects of a first term of second-order concomitant fields generated by the at least one gradient field. The system further includes a second-order correction computing device including at least one processor in communication with at least one memory device. The at least one processor is programmed to control the second-order correction coil assembly by instructing the MR system to apply a compensation field to the second-order correction coil assembly asynchronously with the at least one gradient field.

公开(公告)号：US20230333190A1

公开(公告)日：2023-10-19

申请号：US18133379

申请日：2023-04-11

Applicant: Siemens Healthcare GmbH

Inventor： Stefan Popescu

IPC: G01R33/565 ,  G01R33/387

CPC classification number: G01R33/56581 ,  G01R33/387

Abstract: A method for estimating a magnetic field deviation, a magnetic resonance device, and a computer program product are disclosed. In accordance with the method, at least one gradient value is provided, wherein each gradient value describes a gradient strength of the respective gradient magnetic field, e.g., the setpoint gradient magnetic field. The magnetic resonance device generates a main magnetic field in a main magnetic field direction. The at least one value of a deviation is estimated by applying the at least one gradient value to a magnetic field model. In this case, in accordance with a magnetic field model, a deviation of the gradient magnetic field from a setpoint gradient magnetic field is described by at least one vectorial component in a spatial direction deviating from the main magnetic field direction.

公开(公告)号：US09897678B2

公开(公告)日：2018-02-20

申请号：US13866820

申请日：2013-04-19

Applicant: General Electric Company

Inventor： Ek Tsoon Tan ,  Christopher Judson Hardy ,  Kevin Franklin King ,  Zachary William Slavens ,  Luca Marinelli ,  Robert Marc Lebel

IPC: G01V3/00 ,  G01R33/565 ,  G01R33/563

CPC classification number: G01R33/56581 ,  G01R33/56341 ,  G01R33/56572

Abstract: Systems and methods for correcting magnetic resonance (MR) data are provided. One method includes receiving the MR data and correcting errors present in the MR data due to non-uniformities in magnetic field gradients used to generate the diffusion weighted MR signals. The method also includes correcting errors present in the MR data due to concomitant gradient fields present in the magnetic field gradients by using one or more gradient terms. At least one of the gradient terms is corrected based on the correction of errors present in the MR data due to the non-uniformities in the magnetic field gradients.

公开(公告)号：US09651640B2

公开(公告)日：2017-05-16

申请号：US13602751

申请日：2012-09-04

Applicant: Thorsten Feiweier

Inventor： Thorsten Feiweier

IPC: G01R33/565 ,  A61B5/055 ,  G01R33/483

CPC classification number: G01R33/4835 ,  A61B5/055 ,  G01R33/565 ,  G01R33/56545 ,  G01R33/56581

Abstract: In a magnetic resonance (MR) method system for slice-selective detection and correction of incorrect magnetic resonance data, a first acquisition sequence is implemented to acquire MR data from a first slice of the examination subject that is associated with a chronologically first coherence curve of the magnetization; a second acquisition sequence is implemented to acquire MR data from a second slice of the examination subject that is associated with a chronologically second coherence curve of the magnetization. In slice multiplexing measurement sequences that are characterized by the simultaneous use of the transverse magnetization of the first and second slice within the first and second acquisition sequences slice-selective errors can be detected and corrections made.

公开(公告)号：US20160363643A1

公开(公告)日：2016-12-15

申请号：US15168913

申请日：2016-05-31

Applicant: Toshiba Medical Systems Corporation

Inventor： Masaaki UMEDA

IPC: G01R33/561 ,  G01R33/565

CPC classification number: G01R33/565 ,  G01R33/4816 ,  G01R33/4818 ,  G01R33/482 ,  G01R33/4822 ,  G01R33/4824 ,  G01R33/4826 ,  G01R33/4828 ,  G01R33/483 ,  G01R33/5617 ,  G01R33/56518 ,  G01R33/56581

Abstract: A magnetic resonance imaging apparatus according to an embodiment includes a calculation unit, a collecting unit, and an execution unit. The calculation unit calculates, based on a pulse sequence used in data collection by fast spin echo method, a phase shift amount on at least one echo component included in each of a plurality of echo signals. The correcting unit corrects, based on the calculated phase shift amount, phases of refocusing pulses applied in the pulse sequence such that phases match at least one of between spin echo components, between stimulated echo components, and between a spin echo component and a stimulated echo component. The execution unit executes the pulse sequence in which the refocusing pulses of the corrected phases are applied.

Abstract translation: 根据实施例的磁共振成像装置包括计算单元，收集单元和执行单元。 计算单元基于通过快速自旋回波方法的数据收集中使用的脉冲序列计算包含在多个回波信号中的每一个中的至少一个回波分量的相移量。 校正单元基于所计算的相移量校正施加在脉冲序列中的再聚焦脉冲的相位，使得相位匹配自旋回波分量之间，刺激回波分量之间以及自旋回波分量与受激回波之间的至少一个 零件。 执行单元执行施加了校正相位的重聚焦脉冲的脉冲序列。

公开(公告)号：US20150338490A1

公开(公告)日：2015-11-26

申请号：US14719657

申请日：2015-05-22

Applicant: SIEMENS AKTIENGESELLSCHAFT

Inventor： Andreas Greiser

IPC: G01R33/563 ,  G01R33/30 ,  G01R33/567 ,  G01R33/385 ,  G01R33/56

CPC classification number: G01R33/56316 ,  A61B5/055 ,  G01R33/307 ,  G01R33/385 ,  G01R33/5608 ,  G01R33/56375 ,  G01R33/56383 ,  G01R33/56518 ,  G01R33/56572 ,  G01R33/56581 ,  G01R33/5673

Abstract: In a method and device for generating 4D flow images by operation of a magnetic resonance system, a volume flow data record is recorded, wherein the flow is encoded in a single direction. This is subsequently repeated with all the flow encoding directions. From the raw data associated with the individual flow encoding directions, phase images and magnitude images are calculated. Deformation fields are calculated on the basis of the magnitude images. The deformation fields are applied to the calculated phase images. Finally, a 4D flow velocity field is calculated, on the basis of a phase difference reconstruction of the corrected phase images.

Abstract translation: 在通过操作磁共振系统产生4D流图像的方法和装置中，记录体积流数据记录，其中流程以单个方向被编码。 随后在所有的流编码方向上重复这一点。 从与各个流编码方向相关联的原始数据中，计算相位图像和幅度图像。 基于幅度图像计算变形场。 变形场应用于计算出的相位图像。 最后，基于校正的相位图像的相位差重建来计算4D流速场。

公开(公告)号：US20090256568A1

公开(公告)日：2009-10-15

申请号：US12101279

申请日：2008-04-11

Applicant: Florian Wiesinger ,  Thomas K.F. Foo ,  Mika Vogel ,  Dirk Lange

Inventor： Florian Wiesinger ,  Thomas K.F. Foo ,  Mika Vogel ,  Dirk Lange

IPC: G01R33/48

CPC classification number: G01R33/56316 ,  G01R33/243 ,  G01R33/56518 ,  G01R33/56581

Abstract: A system and method of phase contrast imaging includes a system control programmed to acquire a first set of data and a second set of data via the RF coil assembly during a scan and acquire a third set of data and a fourth set of data via the plurality of magnetic field monitoring devices during the scan. A first single data set from the first and third sets of data is formed, and a second single data set from the second and fourth sets of data is formed. The system control is also programmed to reconstruct a phase contrast image based on the first and second single data sets to correct for spatially-dependent background phase variations.

Abstract translation: 相位对比成像的系统和方法包括被编程以在扫描期间经由RF线圈组件获取第一组数据和第二组数据的系统控制，并经由多个数据采集第三组数据和第四组数据 的磁场监测装置。 形成来自第一和第三组数据的第一单个数据集，并且形成来自第二和第四组数据的第二单个数据集。 系统控制也被编程为基于第一和第二单个数据集重建相位对比图像，以校正空间相关的背景相位变化。

公开(公告)号：US20070222446A1

公开(公告)日：2007-09-27

申请号：US11551850

申请日：2006-10-23

Applicant: Youngkyoo Jung ,  Yogesh Jashnani ,  Walter Block

Inventor： Youngkyoo Jung ,  Yogesh Jashnani ,  Walter Block

IPC: G01V3/00

CPC classification number: G01R33/58 ,  G01R33/4833 ,  G01R33/565 ,  G01R33/56518 ,  G01R33/56563 ,  G01R33/56581

Abstract: A calibration procedure is performed prior to an off-axis MR scan to measure the MRI system timing errors in applying a frequency modulation waveform to the system receiver. Phase errors which otherwise occur when performing non-Cartesian scans are either prospectively reduced by offsetting the timing error or retrospectively offset by applying phase corrections to the acquired image data.

Abstract translation: 在离轴MR扫描之前执行校准程序，以测量向系统接收机施加频率调制波形时的MRI系统定时误差。 通过对所获取的图像数据应用相位校正，通过偏移定时误差或回溯偏移来预先执行非笛卡尔扫描时出现的相位误差。

公开(公告)号：US06512372B1

公开(公告)日：2003-01-28

申请号：US09639911

申请日：2000-08-16

Applicant: Yoshikazu Ikezaki

Inventor： Yoshikazu Ikezaki

IPC: G01N300

CPC classification number: G01R33/56581

Abstract: In order to reduce ghost artifacts due to a Maxwell term phase error caused by a data acquisition read gradient, an n-th Maxwell term collection pulse MTCPn is appended before an inversion RF pulse RF180 for an n-th shot in an I-echo N-shot EPI pulse sequence. The n-th Maxwell term collection pulse MTCPn has a waveform whose time integral value is zero, and gives a bias phase error such that a Maxwell term phase error which is caused by a data acquisition read gradient and contained in data filling out a k-space smoothly varies from a 1st row to an N·I-th row in the direction of a phase encoding axis.

Abstract translation: 为了减少由数据采集读取梯度引起的麦克斯韦尔期限相位误差引起的鬼影，第n个麦克斯韦术语采集脉冲MTCPn被附加在反向RF脉冲RF180之前，用于I回波N中的第n次镜头 -shot EPI脉冲序列。 第n个麦克斯韦术语采集脉冲MTCPn具有时间积分值为零的波形，并且给出偏置相位误差，使得由数据采集读取梯度引起的并包含在填充k- 空间在相位编码轴的方向上从第一行到第NI行平滑地变化。