公开(公告)号：US09921284B2

公开(公告)日：2018-03-20

申请号：US14418246

申请日：2013-09-10

申请人： HITACHI, LTD.

发明人： Takashi Nishihara ,  Hiroyuki Itagaki

IPC分类号： G01V3/00 ,  G01R33/483 ,  A61B5/055 ,  G01R33/36 ,  G01R33/385 ,  G01R33/54 ,  G01R33/561

CPC分类号： G01R33/4836 ,  A61B5/055 ,  G01R33/36 ,  G01R33/385 ,  G01R33/543 ,  G01R33/546 ,  G01R33/561

摘要： In order to provide a technique for improving image quality by selectively exciting only a target region with high precision in either of a two-dimensional spatial selective excitation method or a three-dimensional spatial selective excitation method, selecting a k-space trajectory restraining excitation in a non-target region by side lobes is received. At this time, an excitation region of the selected k-space trajectory is presented to an operator, and the operator can adjust the excitation region through the display. After the adjustment of the excitation region by the operator is reflected, a multi-dimensional spatial selective excitation pulse is stabilized.

公开(公告)号：US09797970B2

公开(公告)日：2017-10-24

申请号：US15097530

申请日：2016-04-13

申请人： The Board of Trustees of The University of Illinois

发明人： Xiaohong Joe Zhou ,  Yi Sui

IPC分类号： G06K9/00 ,  G01R33/483 ,  G01R33/56 ,  G01R33/561

CPC分类号： G01R33/4836 ,  G01R33/5602 ,  G01R33/5608 ,  G01R33/5616

摘要： Representative methods and systems are disclosed for reducing image distortion or increasing spatial resolution in echo planar magnetic resonance imaging. In representative embodiments, a targeted field of view (FOV) image is divided into segments, with each segment having a predetermined overlap region with an adjacent segment, such as in a phase-encoding direction. Image data is acquired for each segment, sequentially or simultaneously, using a reduced phase-encoding FOV with a 2D radiofrequency (RF) excitation pulse, and rotated and scaled magnetic field gradients. The 2D RF excitation pulse may also be modulated, such as onto a plurality of different carrier frequencies, for simultaneous acquisition of multiple segments in the same imaging plane. Using the spatial response of the 2D RF excitation pulse, the acquired image data for each segment of the plurality of segments is combined to generate a combined magnetic resonance image having the targeted field of view.

公开(公告)号：US09684047B2

公开(公告)日：2017-06-20

申请号：US14123186

申请日：2012-02-23

申请人： Arjun Arunachalam

发明人： Arjun Arunachalam

IPC分类号： G01R33/54 ,  G01R33/483 ,  G01R33/48 ,  G01R33/561 ,  G01R33/563

CPC分类号： G01R33/54 ,  G01R33/4824 ,  G01R33/4833 ,  G01R33/4836 ,  G01R33/5611 ,  G01R33/56308

摘要： A system and method for rapid acquisition of MRI data at multiple points in time in an. MRI scan using tailored excitation modules, said method comprising the steps of: obtaining tailored signal excitation modules by using RF excitation pulses in combination with one or more magnetic field gradients; acquiring an aliased k-space dataset at a point in time using a pulse sequence that employs said obtained tailored signal excitation modules, which tag and overlap distinct k-space points; repeating steps (a) and (b) for acquiring aliased k-space datasets at multiple time points in a scan while tagging the overlapped, k-space points as a function of time to obtain an accelerated k-t dataset; undoing k-space aliasing m the acquired k-space datasets by Fourier transforming them along the time axis followed by a filtering process to separate the overlapped points; and performing a Fourier transformation along one or more axes, of the un-aliased k-space datasets to generate image frames for the different time points at which data was acquired.

公开(公告)号：US09664762B2

公开(公告)日：2017-05-30

申请号：US14258376

申请日：2014-04-22

申请人： General Electric Company

发明人： Suchandrima Banerjee ,  Emine Ulku Saritas

IPC分类号： G01R33/483 ,  G01R33/561 ,  G01R33/563

CPC分类号： G01R33/4835 ,  G01R33/4836 ,  G01R33/561 ,  G01R33/5615 ,  G01R33/56341

摘要： A method for reduced field of view magnetic resonance (MR) imaging includes applying a pulse sequence using a plurality of gradient coils and at least one RF coil of a magnetic resonance imaging system. The pulse sequence includes a two dimensional (2D) echo-planar RF excitation pulse with a plurality of side lobes along a slice select axis and a multiband RF refocusing pulse. MR data is acquired in response to the application of the pulse sequence and at least one MR image is reconstructed based on the MR data. The at least one MR image may then be displayed.

公开(公告)号：US09615768B2

公开(公告)日：2017-04-11

申请号：US13496916

申请日：2010-09-16

申请人： Takashi Nishihara ,  Hiroyuki Itagaki ,  Tomohiro Goto

发明人： Takashi Nishihara ,  Hiroyuki Itagaki ,  Tomohiro Goto

IPC分类号： G01R33/48 ,  A61B5/055 ,  A61B5/00 ,  G01R33/44 ,  G01R33/483 ,  G01R33/24 ,  G01R33/3875

CPC分类号： A61B5/055 ,  A61B5/489 ,  G01R33/243 ,  G01R33/3875 ,  G01R33/446 ,  G01R33/4836

摘要： A high-quality image is obtained using a two-dimensional selective excitation method even if the static magnetic field is not uniform. Therefore, non-uniformity of a static magnetic field of a region to be focused in particular in a selective excitation region excited by 2DRF is measured, and a result of the measurement is reflected in an imaging sequence using the 2DRF. For example, a resonance frequency of magnetization obtained from the measurement result is set as an irradiation frequency of the 2DRF. In addition, a shim gradient magnetic field is applied so as to correct the non-uniformity of the magnetization obtained from the measurement result. These are applied only in the imaging sequence using the 2DRF, and an irradiation frequency and a shim gradient magnetic field set in a conventional method are used in other imaging sequences.

公开(公告)号：US20160313424A1

公开(公告)日：2016-10-27

申请号：US15101166

申请日：2013-12-02

申请人： Northwestern University

发明人： Todd Parrish

IPC分类号： G01R33/50 ,  G01R33/563

CPC分类号： G01R33/50 ,  A61B5/055 ,  G01R33/4816 ,  G01R33/4818 ,  G01R33/482 ,  G01R33/4822 ,  G01R33/4824 ,  G01R33/4826 ,  G01R33/4828 ,  G01R33/483 ,  G01R33/4831 ,  G01R33/4833 ,  G01R33/4835 ,  G01R33/4836 ,  G01R33/4838 ,  G01R33/543 ,  G01R33/5601 ,  G01R33/5602 ,  G01R33/56366 ,  G01R33/5676

摘要： Described here are systems and methods for obtaining measurements of both tissue perfusion and permeability with a magnetic resonance imaging (“MRI”) system after the administration of a single dose of contrast agent. To this end, the MRI system is directed to acquire T2*-weighted data, during which the acquired signal values are monitored for a trigger event. When the trigger event occurs, the MRI system is directed to switch from acquiring the T2*-weighted data to acquiring T1-weighted data. The systems and methods of the present invention can thus be used for a fully automated, single acquisition of perfusion and permeability measurements using only a single dose of contrast agent.

摘要翻译： 这里描述了在施用单剂量的造影剂之后用磁共振成像（“MRI”）系统获得组织灌注和渗透性测量的系统和方法。 为此，MRI系统旨在获取T2 *加权数据，在此期间监视所获取的信号值以获得触发事件。 当触发事件发生时，MRI系统被指示从获取T2加权数据到获取T1加权数据。 因此，本发明的系统和方法可以用于仅使用单剂量造影剂的全自动单次采集灌注和渗透性测量。

公开(公告)号：US09435871B2

公开(公告)日：2016-09-06

申请号：US13978930

申请日：2012-01-11

申请人： Kosuke Hirai

发明人： Kosuke Hirai

IPC分类号： G01V3/00 ,  G01R33/48 ,  A61B5/055 ,  G01R33/563 ,  G01R33/561 ,  G01R33/483 ,  G01R33/56

CPC分类号： G01R33/4828 ,  A61B5/055 ,  G01R33/4836 ,  G01R33/5602 ,  G01R33/5613 ,  G01R33/5635

摘要： In order to acquire an image with enhanced contrast between a fluid portion and a stationary portion without extending the imaging time even when an IR pulse is used as an RF pre-pulse, the RF pre-pulse is applied to a region upstream of an imaging region so as to excite longitudinal magnetization of the fluid portion in a negative direction, an echo signal is measured from the imaging region, and an image with enhanced contrast of the fluid portion with respect to the stationary portion is acquired on the basis of phase information of an image reconstructed by using the echo signal.

摘要翻译： 为了获得具有增强的流体部分和静止部分之间的对比度的图像，即使当使用IR脉冲作为RF预脉冲时，也不会延长成像时间，因此将RF预脉冲施加到成像的上游区域 区域，以便沿着负方向激发流体部分的纵向磁化，从成像区域测量回波信号，并且基于相位信息获取流体部分相对于静止部分的对比度增强的图像 通过使用回波信号重建的图像。

公开(公告)号：US20160238685A1

公开(公告)日：2016-08-18

申请号：US15042183

申请日：2016-02-12

申请人： Siemens Aktiengesellschaft

发明人： Radhouene Neji ,  David Andrew Porter

IPC分类号： G01R33/561 ,  G01R33/385 ,  G01R33/54 ,  G01R33/36

CPC分类号： G01R33/5616 ,  G01R33/36 ,  G01R33/3852 ,  G01R33/4835 ,  G01R33/4836 ,  G01R33/543 ,  G01R33/5607

摘要： In a method and magnetic resonance (MR) apparatus for acquiring MR signals from an examination object an RF excitation pulse is directed into the examination object while activating magnetic field gradients in two different spatial directions, such that a magnetization in the examination object in the two different spatial directions is limited by the RF excitation pulse and the switching of the magnetic field gradients. The magnetization is excited in one of the two spatial directions, of a slice selection direction, in a number of periodic layers, so MR signals are generated in the multiple periodic slices. The MR signals in the multiple periodic layers are read out using multiple reception coils of the MR scanner.

摘要翻译： 在用于从检查对象获取MR信号的方法和磁共振（MR）装置中，RF激励脉冲被引导到检查对象中，同时激活两个不同空间方向的磁场梯度，使得两个检查对象中的磁化强度 不同的空间方向受到RF激励脉冲和磁场梯度的切换的限制。 磁化在多个周期性层中的切片选择方向的两个空间方向中的一个激发，因此在多个周期性切片中产生MR信号。 使用MR扫描器的多个接收线圈读出多个周期层中的MR信号。

公开(公告)号：US08508227B2

公开(公告)日：2013-08-13

申请号：US12897806

申请日：2010-10-05

申请人： Martin Haas ,  Peter Ullmann ,  Wolfgang Ruhm ,  Maxim Zaitsev ,  Jürgen Hennig

发明人： Martin Haas ,  Peter Ullmann ,  Wolfgang Ruhm ,  Maxim Zaitsev ,  Jürgen Hennig

IPC分类号： G01V3/00

CPC分类号： G01R33/4836 ,  G01R33/3415 ,  G01R33/385 ,  G01R33/4833 ,  G01R33/5612

摘要： A method for position dependent change in the magnetization in an object, according to a requirement in a magnetic resonance measurement, wherein radio-frequency pulses are irradiated in conjunction with supplementary magnetic fields that vary in space and over time and are superposed on the static and homogeneous basic field of a magnetic resonance measurement apparatus along a z-direction, is characterized in that non-linear supplementary magnetic fields are used, whose spatial gradient of the z-component is not constant at least at one instant of the irradiation, and that the radio-frequency pulses to be irradiated are calculated in advance, wherein progressions over time of the field strengths of the supplementary magnetic fields in the region of the object that are calculated and/or measured position-dependently are included in this calculation. This enables change in the magnetization with an at least locally spatially higher resolution and/or shorter irradiation duration of the RF pulses and supplementary magnetic fields than is feasible with linear supplementary magnetic fields produced by conventional gradient systems. In particular, this is possible under the technical and physiological conditions that currently constrain the performance of the known methods using linear supplementary fields.

摘要翻译： 根据磁共振测量中的要求，对物体的磁化位置相关变化的方法，其中射频脉冲与空间和时间上变化并叠加在静态和 磁共振测量装置沿z方向的均匀基本场的特征在于，使用非线性辅助磁​​场，其至少在照射一瞬间z分量的空间梯度不恒定，并且 预先计算要照射的射频脉冲，其中在该计算中包括在计算和/或测量的对象的区域中的辅助磁场的场强随时间的逐渐增加。 这使得能够利用由常规梯度系统产生的线性补充磁场可行的RF脉冲和辅助磁场的至少局部空间上更高的分辨率和/或更短的照射持续时间来改变磁化。 特别地，这在目前限制使用线性补充领域的已知方法的性能的技术和生理条件下是可能的。

公开(公告)号：US20130127460A1

公开(公告)日：2013-05-23

申请号：US13505296

申请日：2010-10-26

申请人： Gabriele Marianne Beck

发明人： Gabriele Marianne Beck

IPC分类号： G01R33/565

CPC分类号： G01R33/56572 ,  G01N24/08 ,  G01R33/46 ,  G01R33/4836 ,  G01R33/4838 ,  G01R33/543 ,  G01R33/5676

摘要： The invention relates to a method of magnetic resonance (MR) imaging of at least a portion of a body (10) placed in a stationary and substantially homogeneous main magnetic field. The method comprises the following steps; —exciting nuclear magnetization selectively within a spatially restricted volume of interest (20) by subjecting the portion to an imaging sequence (IMG) comprising at least one RF pulse (α) and switched magnetic field gradients (GX/GY); —acquiring at least one MR imaging signal from the volume of interest (20); —exciting nuclear magnetization within a spatially restricted navigator volume (21) by subjecting said portion to a navigator sequence (NAV) comprising at least one RF pulse and switched magnetic field gradients, wherein the navigator volume (21) at least partially overlaps with the volume of interest (20); —acquiring at least one MR navigator signal from said navigator volume (21); —reconstructing a MR image from the acquired MR imaging signals. It is an object of the invention to enable MR imaging with reliable motion detection and high image quality. For this purpose, the invention proposes that the nuclear magnetization within the volume of interest (20) is transformed back into longitudinal magnetization prior to application of the navigator sequence (NAV) by subjecting said portion to an unlabeling sequence(UNLBL) comprising at least one RF pulse (−α).

摘要翻译： 本发明涉及一种放置在固定和基本均匀的主磁场中的体（10）的至少一部分的磁共振（MR）成像方法。 该方法包括以下步骤： 通过对该部分进行包括至少一个RF脉冲（α）和切换磁场梯度（GX / GY）的成像序列（IMG）的选择性地在空间有限的感兴趣体积（20）内激发核磁化。 - 从感兴趣体积（20）获取至少一个MR成像信号; - 通过使所述部分经受包括至少一个RF脉冲和切换磁场梯度的导航序列（NAV）在空间限制的导航器体积（21）内激发核磁化，其中导航器体积（21）至少部分地与体积重叠 的兴趣（20）; - 从所述导航器体积（21）获取至少一个MR导航器信号; - 从所获取的MR成像信号重建MR图像。 本发明的一个目的是能够以可靠的运动检测和高图像质量实现MR成像。 为此目的，本发明提出，在施加导航序列（NAV）之前，将感兴趣体积（20）内的核磁化转变回纵向磁化强度，使得所述部分经受包含至少一个的非标记序列（UNLBL） RF脉冲（-alpha）。