公开(公告)号：US08791700B2

公开(公告)日：2014-07-29

申请号：US13137086

申请日：2011-07-20

申请人： Walter Witschey ,  Daniel Gallichan ,  Maxim Zaitsev ,  Gerrit Schultz ,  Juergen Hennig

发明人： Walter Witschey ,  Daniel Gallichan ,  Maxim Zaitsev ,  Gerrit Schultz ,  Juergen Hennig

IPC分类号： G01V3/00 ,  G01R33/44

CPC分类号： G01R33/445 ,  G01R33/4833

摘要： A method of MR with spatial encoding to generate an image or spectroscopic data of an object of investigation inside an MR apparatus comprises the steps of (a) selecting a volume of interest within the object of investigation, (b) applying an RF pulse to generate a transverse magnetization within the object of investigation, (c) preparing a nonlinear phase distribution within the object of investigation by application of spatially encoding magnetic fields (SEMs), the SEMs comprising of a nonlinear gradient field or a combination of linear and nonlinear gradient fields, (d) effecting primary spatial encoding through application of SEMs, and (e) recording MR signals originating from the object of investigation. Step (c) or (d) thereby comprises applying a sequence of at least two SEMs, at least one of which contains a nonlinear field gradient and at least two of the SEMs having different field geometries. The sequence of SEMs is applied at a point in time from and including the excitation of the object of interest in step (b) up to and including the recording of the MR signals in step (e), to thereby introduce a temporal shift of the signals arising from spatially different locations within the selected volume of interest, that is to thereby introduce a shift of local spatial frequency components. A sampling window for recording of the respective MR signals is set and signals originating from the volume of interest are recorded in step (e) and undesired signals originating from outside the volume of interest are suppressed.

摘要翻译： 一种具有空间编码以在MR装置内产生调查对象的图像或光谱数据的MR的方法包括以下步骤：（a）选择调查对象内的感兴趣体积，（b）施​​加RF脉冲以产生 在研究对象内的横向磁化，（c）通过应用空间编码磁场（SEM）在研究对象内准备非线性相位分布，包括非线性梯度场或线性和非线性梯度场的组合的SEM ，（d）通过应用SEM实现主要空间编码，（e）记录源自调查对象的MR信号。 步骤（c）或（d）由此包括施加至少两个SEM序列，其中至少一个包含非线性场梯度和具有不同场几何形状的至少两个SEM。 在从步骤（b）中的感兴趣对象的激发到包括步骤（e）中的MR信号的记录的时间点上施加SEM序列，从而引入时间偏移 在所选择的感兴趣体积内由空间不同的位置产生的信号，从而引入局部空间频率分量的偏移。 设置用于记录各个MR信号的采样窗口，并且在步骤（e）中记录来自感兴趣体积的信号，并且抑制源于感兴趣体积之外的不需要的信号。

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：US20120249137A1

公开(公告)日：2012-10-04

申请号：US13414737

申请日：2012-03-08

申请人： Walter Witschey ,  Maxim Zaitsev ,  Jürgen Hennig ,  Gerrit Schultz ,  Daniel Gallichan

发明人： Walter Witschey ,  Maxim Zaitsev ,  Jürgen Hennig ,  Gerrit Schultz ,  Daniel Gallichan

IPC分类号： G01R33/58

CPC分类号： G01R33/3875

摘要： A method to compensate for the magnetic field heterogeneity inside an object of investigation in a MR device obtains an uncorrected magnetic field distribution of the object and executes an MR sequence with a desired k-space coverage by applying RF pulses to generate a transverse magnetization within the object. MR signal data is recorded, magnetic field shimming parameters are dynamically updated and MR signal data are reconstructed to produce images or localized spectroscopic data. Artifacts in a reconstructed image resulting from an uncorrected magnetic field distribution are suppressed by temporally separating MR signals originating from at least two different sub-volumes within a volume of transverse magnetization by generating a nonlinear phase distribution within the object and by dynamically updating shimming parameters to compensate for the field inhomogeneity distributions within the different sub-volumes in the volume of transverse magnetization.

摘要翻译： 用于补偿MR装置内的调查对象内的磁场异质性的方法获得对象的未校正的磁场分布，并通过施加RF脉冲来产生具有期望的k空间覆盖的MR序列，以在其内产生横向磁化 目的。 记录MR信号数据，动态地更新磁场匀场参数，重建MR信号数据以产生图像或局部光谱数据。 通过在对象内生成非线性相位分布，并且通过动态地更新匀场参数来暂时分离来自横向磁化体积内的至少两个不同子体积的MR信号，从而抑制由未校正的磁场分布产生的重构图像中的人造物 补偿横向磁化量的不同子体积内的场不均匀性分布。

公开(公告)号：US07906968B2

公开(公告)日：2011-03-15

申请号：US12291680

申请日：2008-11-12

申请人： Juergen Hennig ,  Maxim Zaitsev ,  Anna Welz ,  Gerrit Schultz

发明人： Juergen Hennig ,  Maxim Zaitsev ,  Anna Welz ,  Gerrit Schultz

IPC分类号： G01V3/00

CPC分类号： G01R33/385 ,  G01R33/3415 ,  G01R33/3854 ,  G01R33/48

摘要： A nuclear magnetic resonance (NMR) imaging method in which, with the aid of a gradient system, a spatially and temporally variable magnetic field Bgrad is generated, for the at least two-dimensional spatial encoding of NMR measurement signals in a measurement sample region to be imaged, where the magnetic field Bgrad is employed in at least two forms Bgrad1 and Bgrad2 in the measurement sample region to be imaged during a single measurement cycle from excitation to reading of the NMR measurement signals, where the first form Bgrad1 has essentially ns poles, where ns is an even number > 2, and has ns essentially sectorial sub-regions, in each of which the magnetic field Bgrad is locally monotonic in one direction, where the measurement signals from the measurement sample are recorded by means of at least ns receiver coils which have different sensitivity over the ns sub-regions of the region to be imaged, is characterized in that the second form Bgrad2 is essentially identical to the first form Bgrad1 % with the second form Bgrad2 being rotated by an angle Δφ, where Δ ⁢ ⁢ φ = 360 ⁢ ° 2 · n ⁢ ⁢ s , relative to the first form Bgrad1. The invention provides an NMR imaging method in which a high-resolution image of the region to be imaged is obtained more quickly utilizing the advantages of NBSEMs.

摘要翻译： 一种核磁共振（NMR）成像方法，其中借助于梯度系统产生空间和时间上可变的磁场Bgrad，对于测量样本区域中的NMR测量信号的至少二维空间编码， 成像，其中在从激励到读取NMR测量信号的单个测量周期期间在要成像的测量样本区域中至少两种形式Bgrad1和Bgrad2采用磁场Bgrad，其中第一形式Bgrad1具有基本上为ns的极点 ，其中ns是偶数> 2，并且具有基本上是扇形子区域，其中每个子场中的磁场Bgrad在一个方向上局部单调，其中来自测量样本的测量信号通过至少ns 具有与要成像的区域的ns子区域不同的灵敏度的接收器线圈的特征在于，第二形式Bgrad2基本上与fi 第一种形式Bgrad1％，第二种形式Bgrad2旋转角度＆Dgr;＆phgr;其中＆Dgr; ⁢＆phgr = 360°2·n⁢s，相对于第一形式Bgrad1。 本发明提供了一种NMR成像方法，其中使用NBSEM的优点更快地获得待成像区域的高分辨率图像。

公开(公告)号：US20100102819A1

公开(公告)日：2010-04-29

申请号：US12258779

申请日：2008-10-27

申请人： Maxim ZAITSEV ,  Daniel N. SPLITTHOFF ,  Jurgen HENNIG

发明人： Maxim ZAITSEV ,  Daniel N. SPLITTHOFF ,  Jurgen HENNIG

IPC分类号： G01R33/54

CPC分类号： G01R33/56563 ,  G01R33/543 ,  G01R33/5611

摘要： The pursuit for ever higher field strengths and faster data acquisitions has led to the construction of coil arrays with high numbers of elements. With the SENSE technique it has been shown, how the sensitivity of those elements can be used for spatial image encoding. A method in accordance with the present invention, largely abstains from using encoding gradients. The resulting sensitivity encoded free induction decay (FID) data is then not used for imaging, but for determining field inhomogeneity distribution. The method has therefore been termed SSH for Sense SHimming.

摘要翻译： 追求更高的现场优势和更快的数据采集导致了线圈阵列的构建，其数量众多。 使用SENSE技术，已经显示出这些元素的灵敏度如何被用于空间图像编码。 根据本发明的方法，在很大程度上不使用编码梯度。 然后，所得到的灵敏度编码的自由感应衰减（FID）数据不用于成像，而是用于确定场不均匀性分布。 因此，该方法被称为Sense Shimming的SSH。

公开(公告)号：US07235972B2

公开(公告)日：2007-06-26

申请号：US10514801

申请日：2003-05-14

申请人： N. Joni Shah ,  Maxim Zaitsev ,  Martin Osmund Leach ,  David John Collins ,  James D'Arcy

发明人： N. Joni Shah ,  Maxim Zaitsev ,  Martin Osmund Leach ,  David John Collins ,  James D'Arcy

IPC分类号： G01V3/00

CPC分类号： G01R33/50 ,  G01R33/561 ,  G01R33/5616

摘要： An object is examined by detecting properties of the object at different times within a space formed by spatial frequencies. This is done such that temporally consecutive recordings are made in overlapping regions of the spatial frequency space and also in regions of the spatial frequency space that differ from one another.

摘要翻译： 通过在由空间频率形成的空间内的不同时间检测物体的特性来检查物体。 这样做使得在空间频率空间的重叠区域中以及在彼此不同的空间频率空间的区域中进行时间上连续的记录。

公开(公告)号：US08368400B2

公开(公告)日：2013-02-05

申请号：US12382202

申请日：2009-03-11

申请人： Martin Haas ,  Maxim Zaitsev ,  Jürgen Hennig

发明人： Martin Haas ,  Maxim Zaitsev ,  Jürgen Hennig

IPC分类号： G01V3/00

CPC分类号： G01R33/483 ,  G01R33/4833 ,  G01R33/4836 ,  G01R33/543 ,  G01R33/5611 ,  G01R33/5612 ,  G01R33/5613 ,  G01R33/5617

摘要： A magnetic resonance method for using radio frequency pulses for spatially selective and frequency selective or multidimensionally spatially selective excitation of an ensemble of nuclear spins with an initial distribution of magnetization in a main magnetic field aligned along a z-axis, wherein a spin magnetization with a given target distribution of magnetization is generated, and for refocusing the spin magnetization, is characterized in that the radio frequency pulse is used as a sequence of sub-pulses of independent duration, courses of gradients and spatial and/or spectral resolution, comprising one or more large angle RF pulses with tip angles greater than or approximately equal to 15°, which generate a gross distribution of magnetization approximating the target distribution of magnetization or a desired modification of the distribution of magnetization with a mean deviation less than or approximately equal to 15°, wherein the actual effect of the LAPs on the distribution of spin magnetization before the radio frequency pulse is used is calculated by integration of the Bloch equations without small angle approximation, and one or more small angle RF pulses=SAPs with tip angles less than or approximately equal to 15° reducing the difference between the target distribution of magnetization and the gross distribution of magnetization caused by the LAPs.

摘要翻译： 一种磁共振方法，用于使用射频脉冲用于沿着z轴对准的主磁场中的初始磁化分布的核自旋组合的空间选择性或频率选择性或多维空间选择性激发，其中自旋磁化与 产生磁化的目标分布，并且对于重新聚焦自旋磁化，其特征在于射频脉冲被用作独立持续时间，梯度，空间和/或光谱分辨率的子脉冲序列，包括一个或 具有大于或大约等于15°的尖角的更大的角度RF脉冲，其产生近似磁化的目标分布的磁化的总体分布或磁化分布的期望修改，平均偏差小于或等于15 °，其中LAP对分布的实际效果 使用无线电频率脉冲之前的自旋磁化是通过不使用小角度近似的Bloch方程的积分计算的，并且一个或多个小角度RF脉冲=具有小于或等于15°的尖角的SAP减少目标分布之间的差异 的磁化和由LAP引起的磁化的总分布。

公开(公告)号：US08354844B2

公开(公告)日：2013-01-15

申请号：US12645505

申请日：2009-12-23

申请人： Maxim Zaitsev ,  Juergen Hennig

发明人： Maxim Zaitsev ,  Juergen Hennig

IPC分类号： G01V3/00

CPC分类号： G01R33/5611 ,  G01R33/4836

摘要： A method for accelerating data acquisition in MRI with N-dimensional spatial encoding has a first method step in which a transverse magnetization within an imaged object volume is prepared having a non-linear phase distribution. Primary spatial encoding is thereby effected through application of switched magnetic fields. Two or more RF receivers are used to simultaneously record MR signals originating from the imaged object volume, wherein, for each RF receiver, an N-dimensional data matrix is recorded which is undersampled by a factor Ri per selected k-space direction. Data points belonging to a k-space matrix which were not recoded by a selected acquisition schema are reconstructed using a parallel imaging method, wherein reference information concerning receiver coil sensitivities is extracted from a phase-scrambled reconstruction of the undersampled data matrix. The method generates a high-resolution image free of artifacts in a time-efficient manner by improving data sampling efficiency and thereby reducing overall data acquisition time.

摘要翻译： 用于加速具有N维空间编码的MRI中的数据采集的方法具有第一方法步骤，其中准备具有非线性相位分布的成像对象体积内的横向磁化强度。 从而通过应用开关磁场来实现主空间编码。 使用两个或更多个RF接收器来同时记录来自成像对象体积的MR信号，其中，对于每个RF接收机，记录N个数据矩阵，其被每个选择的k空间方向的因子Ri欠采样。 使用并行成像方法重建属于未被所选择的采集模式重新编码的k空间矩阵的数据点，其中关于接收机线圈灵敏度的参考信息是从欠采样数据矩阵的相位加扰重建中提取的。 该方法通过提高数据采样效率从而减少总体数据采集时间，以时间有效的方式产生无瑕疵的高分辨率图像。

公开(公告)号：US20120262171A1

公开(公告)日：2012-10-18

申请号：US13443908

申请日：2012-04-11

申请人： Hans Weber ,  Maxim Zaitsev ,  Daniel Gallichan ,  Juergen Hennig

发明人： Hans Weber ,  Maxim Zaitsev ,  Daniel Gallichan ,  Juergen Hennig

IPC分类号： G01R33/54

CPC分类号： G01R33/4833 ,  G01R33/483 ,  G01R33/4835 ,  G01R33/4836

摘要： A method of MR imaging applies a magnetic field Bgrad1 having a spatially non-linear dependence to select a volume of at least one curved slice. The slice is described by its midsurface AM, a volume of the selected slice being made up of nν partial volumes in each of which gradients of at least one pair of remaining superimposed magnetic fields Bgradi (i>1) exhibit an angle dependence of 70° to 110° with respect to one another and with respect to the normal of the midsurface AM. At least one superimposed magnetic field of the respective pair exhibits a spatially non-linear dependence and combinations of these pairs are used for spatial encoding. In this way, curved surfaces can be mapped efficiently in high resolution and the method can be adapted to the slice shape.

摘要翻译： MR成像的方法应用具有空间非线性依赖性的磁场Bgrad1来选择至少一个弯曲切片的体积。 切片由其中心面AM描述，所选切片的体积由n＆ngr组成; 至少一对剩余叠加磁场Bgradi（i> 1）的梯度中的每一个的部分体积相对于彼此表现出70°至110°的角度依赖性，并且相对于中空面AM的法线呈现角度依赖性。 相应对的至少一个叠加的磁场表现出空间非线性相关性，并且这些对的组合用于空间编码。 以这种方式，可以高分辨率地有效地映射曲面，并且该方法可以适应于切片形状。

公开(公告)号：US20110080169A1

公开(公告)日：2011-04-07

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： G01R33/48

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。