公开(公告)号：US08729897B2

公开(公告)日：2014-05-20

申请号：US13196135

申请日：2011-08-02

申请人： David Andrew Porter

发明人： David Andrew Porter

IPC分类号： G01V3/00

CPC分类号： G01R33/5617 ,  G01R33/4836 ,  G01R33/56341 ,  G01R33/565

摘要： In a method and magnetic resonance (MR) apparatus to acquire spin echo-based MR signals of an examination subject with a multi-spin echo sequence with multiple refocusing pulses after a single excitation pulse in an MR system that has a multichannel RF transmission and reception module: detect a spatial, two-dimensional phase distribution in the examination subject is detected by acquiring navigator signals, a phase and amplitude distribution for the individual transmission channels of the RF transmission and reception module is calculated to generate a magnetic field B1 for one of the RF refocusing pulses to generate the spin echo-based MR signal under consideration of the spatial phase distribution of the navigator signals, and this RF refocusing pulse is radiated via the multichannel RF transmission and reception module with the calculated phase and amplitude distributions of the individual transmission channels.

摘要翻译： 在具有多通道RF发射和接收的MR系统中的单个激励脉冲之后，利用具有多个重聚焦脉冲的多自旋回波序列获取检查对象的基于自旋回波的MR信号的方法和磁共振（MR）装置中 模块：通过获取导航信号检测检查对象中的空间二维相位分布，计算RF发送和接收模块的各个传输信道的相位和幅度分布，以产生一个磁场B1 RF再聚焦脉冲，以在考虑导航信号的空间相位分布的情况下产生基于自旋回波的MR信号，并且该RF重聚焦脉冲经由多通道RF发射和接收模块以所计算的个体的相位和幅度分布被辐射 传输通道。

公开(公告)号：US20120194190A1

公开(公告)日：2012-08-02

申请号：US13496921

申请日：2010-09-22

申请人： Tomohiro Goto ,  Takashi Nishihara ,  Hiroyuki Itagaki

发明人： Tomohiro Goto ,  Takashi Nishihara ,  Hiroyuki Itagaki

IPC分类号： G01R33/48

CPC分类号： G01R33/4836 ,  A61B5/055 ,  G01R33/4833 ,  G01R33/4838 ,  G01R33/543 ,  G01R33/546 ,  G01R33/5676

摘要： In imaging using 2-dimensional selective excitation pulses, regardless of applications thereof, a technique for obtaining a high quality image is provided.In the technique, a 2-dimensional selective excitation sequence is carried out while changing a coefficient for determining the cylinder diameter of a region excited by the 2-dimensional selective excitation sequence and a time difference for determining an offset position.The obtained excitation region and a desired region are compared with each other, and the coefficient and time difference with which the obtained excitation region and the desired region match each other are determined to be the optimum ones.The determination processing may be performed as an initial adjustment, may be performed according to need in each imaging, or may be performed on a per-application basis.

摘要翻译： 在使用二维选择性激发脉冲的成像中，无论其应用如何，都提供了获得高质量图像的技术。 在该技术中，在改变用于确定由二维选择激励序列激发的区域的圆柱体直径的系数和用于确定偏移位置的时间差的同时，执行二维选择性激励序列。 将获得的激发区域和期望区域进行比较，将获得的激发区域和期望区域相互匹配的系数和时间差确定为最佳。 可以根据每次成像中的需要执行确定处理作为初始调整，或者可以在每个应用的基础上执行。

公开(公告)号：US20120194185A1

公开(公告)日：2012-08-02

申请号：US13198348

申请日：2011-08-04

申请人： Dieter Ritter

发明人： Dieter Ritter

IPC分类号： G01R33/48

CPC分类号： G01R33/5612 ,  G01R33/4836 ,  G01R33/543

摘要： A method and control sequence determination facility for determining a magnetic resonance system activation sequence that includes a multichannel pulse train with a plurality of individual HF-pulse trains to be emitted by the magnetic resonance system via different independent high-frequency transmit channels of a transmit facility in a parallel manner are described. The multichannel pulse train is calculated based on a k-space gradient trajectory and a predetermined target magnetization using an HF pulse optimization method. In the HF pulse optimization method, optimization of the multichannel pulse train and/or the k-space gradient trajectory takes account of at least one hardware operating parameter of the transmit facility.

摘要翻译： 一种用于确定磁共振系统激活序列的方法和控制顺序确定设备，其包括具有多个单独HF脉冲序列的多通道脉冲序列，以由磁共振系统经由发射设备的不同独立高频发射信道发射 以平行方式描述。 使用HF脉冲优化方法，基于k空间梯度轨迹和预定目标磁化来计算多通道脉冲串。 在HF脉冲优化方法中，多信号脉冲串和/或k空间梯度轨迹的优化考虑了传输设施的至少一个硬件操作参数。

公开(公告)号：US08115486B2

公开(公告)日：2012-02-14

申请号：US12260612

申请日：2008-10-29

申请人： Hideta Habara ,  Yoshitaka Bito

发明人： Hideta Habara ,  Yoshitaka Bito

IPC分类号： G01V3/00 ,  A61B5/055 ,  G06K9/00

CPC分类号： G01R33/3607 ,  G01R33/288 ,  G01R33/4833 ,  G01R33/4836

摘要： An MRI apparatus comprises a waveform controlling means for calculating a radio frequency pulse and applying the pulse to an irradiating means, and the waveform controlling means reads out a radio frequency pulse waveform vector from a first memory means which memorizes multiple radio frequency pulse waveform vectors, calculates a simulated irradiation pattern, and calculates a radio frequency pulse waveform which gives the minimum value of weighted sum of squares of differences of absolute values and squares of differences of phases for an ideal irradiation pattern and the simulated irradiation pattern. An RF pulse waveform showing superior ideal irradiation pattern reproducibility and providing reduced power of the RF waveform is formed, and safety of MRI subject is improved by performing imaging using such an RF pulse.

摘要翻译： MRI装置包括波形控制装置，用于计算射频脉冲并将脉冲施加到照射装置，波形控制装置从存储多个射频脉冲波形向量的第一存储装置读出射频脉冲波形向量， 计算模拟照射图案，并计算给出理想照射图案和模拟照射图案的相位差绝对值和平方差的加权平方和的最小值的射频脉搏波形。 形成显示优异的理想照射图案再现性并且提供RF波形的功率降低的RF脉冲波形，并且通过使用这样的RF脉冲进行成像来提高MRI对象的安全性。

公开(公告)号：US08022701B2

公开(公告)日：2011-09-20

申请号：US12337388

申请日：2008-12-17

申请人： Jyh-Horng Chen ,  Tzi-Dar Chiueh ,  Edzer L. Wu ,  Li-Wei Kuo

发明人： Jyh-Horng Chen ,  Tzi-Dar Chiueh ,  Edzer L. Wu ,  Li-Wei Kuo

IPC分类号： G01V3/00

CPC分类号： G01R33/4835 ,  G01R33/446 ,  G01R33/4822 ,  G01R33/4836 ,  G01R33/54 ,  G01R33/543 ,  G01R33/5615

摘要： Provided is a method for simultaneously acquiring magnetic resonance slices/slabs of a subject. The method comprises steps as follows. First, apply one or more than one RF pulse, which carries at least two frequency components, and a slice/slab selection magnetic field gradient so that at least two slices/slabs of the subject respectively corresponding to the at least two frequency components are excited simultaneously. Second, apply a spatial encoding magnetic field gradient. Third, apply a slice/slab separation magnetic field gradient so as to separate the at least two slices/slabs. The method according to the present invention can be used to acquire data for simultaneously reconstructing multiple slices/slabs. The method is compatible with existing MRI systems.

摘要翻译： 提供了一种用于同时获取被检体的磁共振切片/板的方法。 该方法包括以下步骤。 首先，应用一个或多于一个RF脉冲，其携带至少两个频率分量，以及切片/平板选择磁场梯度，使得分别对应于至少两个频率分量的被摄体的至少两个切片/平板被激发 同时。 二，应用空间编码磁场梯度。 第三，应用切片/平板分离磁场梯度，以分离至少两个切片/平板。 根据本发明的方法可以用于获取用于同时重建多个切片/平板的数据。 该方法与现有MRI系统兼容。

公开(公告)号：US20100066362A1

公开(公告)日：2010-03-18

申请号：US12517573

申请日：2007-12-05

申请人： Peter Ullmann

发明人： Peter Ullmann

IPC分类号： G01R33/48

CPC分类号： G01R33/583 ,  G01R33/4836 ,  G01R33/5611 ,  G01R33/5612 ,  G01R33/586

摘要： A method for determining amplitude and phase dependencies of radio frequency pulses that are irradiated during traversal of a defined k-space trajectory to produce a spatial pattern of the transverse magnetization in an MR experiment using at least one RF transmission antenna, is characterized in that, in a calibration step, a set of basic pulses is defined, each basic pulse is irradiated individually, the specified k-space trajectory is traversed and at least one set of basic patterns is produced by detection of the MR signals thus excited, which in a range to be examined of the object, are proportional to the complex transverse magnetization produced, wherein the k-space trajectory is traversed fully identically every time at least from the beginning of the irradiation of each basic pulse, and, in a calculation step, a defined target pattern is approximated with a linear combination of the basic patterns of a set or with a mathematical association of linear combinations, with which, within each set, the basic patterns are identically combined, and the amplitude and phase dependencies to be determined are obtained as the corresponding linear combination of the basic pulses. Experimental imperfections can be intrinsically compensated for in this way.

摘要翻译： 用于确定在使用至少一个RF发射天线的MR实验中在定义的k空间轨迹遍历期间照射的射频脉冲的幅度和相位依赖性以产生横向磁化的空间模式的方法，其特征在于， 在校准步骤中，定义一组基本脉冲，单独照射每个基本脉冲，遍历指定的k空间轨迹，并通过检测由此激发的MR信号产生至少一组基本图案， 要检查物体的范围与产生的复杂横向磁化率成比例，其中至少从每个基本脉冲的照射的开始每次至少从每个基本脉冲开始遍历k空间轨迹，并且在计算步骤中， 定义的目标模式用一组的基本模式或线性组合的数学关联的线性组合近似， 在每组中，基本模式被相同地组合，并且获得要确定的幅度和相位依赖性作为基本脉冲的相应线性组合。 实际的缺陷可以以这种方式进行固有的补偿。

公开(公告)号：US20100052679A1

公开(公告)日：2010-03-04

申请号：US12550074

申请日：2009-08-28

申请人： Adam C. Zelinski ,  Lawrence L. Wald ,  Elfar Adalsteinsson ,  Vivek K. Goyal ,  Vijay Alagappan

发明人： Adam C. Zelinski ,  Lawrence L. Wald ,  Elfar Adalsteinsson ,  Vivek K. Goyal ,  Vijay Alagappan

IPC分类号： G01R33/48

CPC分类号： G01R33/5611 ,  G01R33/3664 ,  G01R33/4833 ,  G01R33/4836 ,  G01R33/5612

摘要： A method for target-dependent, sparsity-enforced selection for choosing a substantially optimal connection of radiofrequency (“RF”) transmitters to the elements of the RF coil array is provided. In particular, a method is provided that selects the linear combinations of the “N” spatial mode profiles of a transmission RF coil array, such that the k-space trajectory and pulse duration acceleration capabilities of the array are advantageously utilized. A sparsity-enforcement method that determines a subset of the available spatial modes for a parallel transmission RF coil array is employed to this end. In this manner, the utilization of the encoding power of a highly-parallel N-mode coil array in a system with only “P” available excitation channels is enabled.

摘要翻译： 提供了用于选择用于选择射频（RF））发射机到RF线圈阵列的元件的基本上最佳连接的目标依赖，稀疏执行选择的方法。 具体地，提供了一种选择发射RF线圈阵列的“N”个空间模式分布的线性组合的方法，使得有利地利用阵列的k空间轨迹和脉冲持续时间加速能力。 为此，采用了稀疏执行方法来确定并行传输RF线圈阵列的可用空间模式的子集。 以这种方式，能够在仅具有“P”可用激励信道的系统中利用高并行N模式线圈阵列的编码功率。

公开(公告)号：US20080284439A1

公开(公告)日：2008-11-20

申请号：US11750478

申请日：2007-05-18

申请人： Dan Xu ,  Kevin F. King

发明人： Dan Xu ,  Kevin F. King

IPC分类号： G01R33/34

CPC分类号： G01R33/4836 ,  A61B5/055 ,  G01R33/4824 ,  G01R33/4833

摘要： A system and method are provided for adjusting RF pulses and gradient waveforms to reduce B1 field magnitude in MR imaging sequences. When an RF pulse is presented which has a high amplitude segment that would exceed a maximum B1 magnitude, the system and method provided herein can apply a variable slew rate design technique. A slew rate of at least one gradient waveform can be varied to reduce a B1 field magnitude during transmission of the high amplitude segment of the RF pulse. By controlling the slew rate of gradient waveforms for non-Cartesian k-space trajectories according to a calculated maximum allowable slew rate function, embodiments of the system and method can, in effect, reduce gradient amplitude.

摘要翻译： 提供了一种用于调整RF脉冲和梯度波形以减少MR成像序列中的B 1场强的系统和方法。 当提供具有超过最大B 1> 1值的高幅度段的RF脉冲时，本文提供的系统和方法可以应用可变转换速率设计技术。 可以改变至少一个梯度波形的转换速率，以在RF脉冲的高幅度段的传输期间减小B SUB场强。 通过根据计算出的最大允许转换速率函数控制非笛卡尔k空间轨迹的梯度波形的转换速率，该系统和方法的实施例实际上可以减小梯度幅度。

公开(公告)号：US20080272783A1

公开(公告)日：2008-11-06

申请号：US12112499

申请日：2008-04-30

申请人： Kazuya Okamoto

发明人： Kazuya Okamoto

IPC分类号： G01V3/00

CPC分类号： G01R33/34046 ,  G01R33/3415 ,  G01R33/3664 ,  G01R33/4833 ,  G01R33/4836 ,  G01R33/5612

摘要： A magnetic resonance imaging apparatus that applies a gradient magnetic field and a radio-frequency magnetic field to a subject in a static magnetic field to image the subject based on magnetic resonance signals emitted from the subject, includes a unit which generates K transmission radio-frequency pulse signals required to produce the radio-frequency magnetic field, an allocation unit which allocates the K transmission radio-frequency pulse signals to K in M transmission signal paths, a connection unit to which at most M radio-frequency coils are attachable and which selectively connects the M transmission signal paths and M reception signal paths to the radio-frequency coils, a selection unit which selects N in magnetic resonance signals which are respectively received by the at most M radio-frequency coils and transmitted through the at most M reception signal paths, and a unit which performs reception processing for each of the selected N magnetic resonance signals.

摘要翻译： 一种磁共振成像装置，其将基于从被检体发出的磁共振信号对静态磁场施加梯度磁场和射频磁场，对被摄体进行成像，包括：生成K个发射频率的单位 产生射频磁场所需的脉冲信号，在M个发送信号路径中将K个发送射频脉冲信号分配给K的分配单元，至多可连接M个射频线圈的连接单元， 将M个发送信号路径和M个接收信号路径连接到射频线圈;选择单元，其选择分别由最多M个射频线圈接收并通过最多M个接收信号发送的磁共振信号中的N个 路径，以及对所选择的N个磁共振信号进行接收处理的单元。

公开(公告)号：US07372270B2

公开(公告)日：2008-05-13

申请号：US11531090

申请日：2006-09-12

申请人： KyungHyun Sung ,  Krishna Nayak

发明人： KyungHyun Sung ,  Krishna Nayak

IPC分类号： G01V3/00

CPC分类号： G01R33/4836 ,  G01R33/4833 ,  G01R33/5659

摘要： A method and system are described for compensating for non-uniformity of excitation field B1+ in magnetic resonance imaging (MRI) of an object. The variation in the RF excitation field B1+ is measured over a region of interest (ROI) in the object, the B1+ field causing nuclear spins in the object to flip at a flip angle when B1+ is applied to the object. The flip angle profile is designed to be proportional to a reciprocal of the measured variation in the excitation field B1+. One or more control parameters of the estimated flip angle profile is adjusted, in accordance with the measured variation in B1+, so as to cancel out variation in actual flip angle until a profile of the actual flip angle is achieved that is substantially uniform throughout the ROI.

摘要翻译： 描述了用于补偿对象的磁共振成像（MRI）中的激励场B1 +的不均匀性的方法和系统。 在对象中的感兴趣区域（ROI）上测量RF激励场B1 +的变化，当B1 +被施加到对象时，引起对象中的核自旋的B1 +场以翻转角翻转。 翻转轮廓被设计成与激励场B1 +中测量的变化的倒数成比例。 根据所测量的B1 +的变化，调整估计的翻转角轮廓的一个或多个控制参数，以抵消实际翻转角度的变化，直到达到在整个ROI内基本均匀的实际翻转角的轮廓 。