公开(公告)号：US20090256570A1

公开(公告)日：2009-10-15

申请号：US12422512

申请日：2009-04-13

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

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

IPC分类号： G01R33/32

CPC分类号： G01R33/561 ,  G01R33/4824 ,  G01R33/4836 ,  G01R33/5611 ,  G01R33/5612

摘要： A system and method is provided for simultaneously designing a radiofrequency (“RF”) pulse waveform and a magnetic field gradient waveform in a magnetic resonance imaging (“MRI”) system. The method includes determining a desired pattern of RF excitation and determining, from the desired pattern of RF excitation, a plurality of k-space locations indicative of the magnetic field gradient waveform and a plurality of complex weighting factors indicative of RF energy deposited at each k-space location. The method also includes calculating, from the determined k-space locations, the magnetic field gradient waveform and calculating, from the complex weighting factors, the RF pulse waveform that will produce the desired pattern of RF excitation when produced with the calculated magnetic field gradient.

摘要翻译： 提供了一种在磁共振成像（“MRI”）系统中同时设计射频（“RF”）脉冲波形和磁场梯度波形的系统和方法。 该方法包括确定期望的RF激励模式，并根据所需的RF激励模式确定表示磁场梯度波形的多个k空间位置以及指示在每个k处沉积RF能量的多个复加权系数 - 空间位置。 该方法还包括从确定的k空间位置计算磁场梯度波形，并从复数加权因子计算当用所计算的磁场梯度产生时将产生期望的RF激励模式的RF脉冲波形。

公开(公告)号：US10261145B2

公开(公告)日：2019-04-16

申请号：US14648485

申请日：2013-12-02

申请人： Lawrence Wald ,  Jason Stockmann

发明人： Lawrence Wald ,  Jason Stockmann

IPC分类号： G01V3/00 ,  G01R33/3415 ,  G01R33/341 ,  G01R33/3875 ,  A61B5/055

摘要： A system and method for magnetic resonance imaging (MRI) and static field (B0) shimming. A coil system includes a conductive loop configured to be arranged proximate to a region of interest (ROI). The coil system also includes an alternating current (AC) circuit electrically connecting the conductive loop to an AC electrical connection configured to be coupled to an MRI system to communicate medical imaging signals received by the conductive loop from the ROI during a medical imaging procedure to the MRI system. The coil system further includes a direct current (DC) circuit electrically connecting the conductive loop to a DC electrical connection configured to be coupled to a DC power source and a plurality of circuit components configured to block DC signals from reaching the AC electrical connection in order to produce a spatially varying static magnetic field for shimming inhomogenieties of the static field.

公开(公告)号：US20150323633A1

公开(公告)日：2015-11-12

申请号：US14707598

申请日：2015-05-08

申请人： Stephen Cauley ,  Berkin Bilgic ,  Kawin Setsompop ,  Lawrence Wald

发明人： Stephen Cauley ,  Berkin Bilgic ,  Kawin Setsompop ,  Lawrence Wald

IPC分类号： G01R33/561 ,  G01R33/567 ,  G01R33/385

CPC分类号： G01R33/5608 ,  G01R33/385 ,  G01R33/5611 ,  G01R33/5615 ,  G01R33/5673

摘要： Systems and methods for reconstructing images using a hierarchically semiseparable (“HSS”) solver to compactly represent the inverse encoding matrix used in the reconstruction are provided. The reconstruction method includes solving for the actual inverse of the encoding matrix using a direct (i.e., non-iterative) HSS solver. This approach is contrary to conventional reconstruction methods that repetitively evaluate forward models (e.g., compressed sensing or parallel imaging forward models).

摘要翻译： 提供了使用分层半分离（“HSS”）求解器重建图像的系统和方法，以紧凑地表示重构中使用的逆编码矩阵。 重建方法包括使用直接（即非迭代）HSS求解器求解编码矩阵的实际逆。 这种方法与重复地评估前向模型（例如，压缩感测或平行成像正向模型）的常规重建方法相反。

公开(公告)号：US20070282194A1

公开(公告)日：2007-12-06

申请号：US11839094

申请日：2007-08-15

申请人： Graham Wiggins ,  Lawrence Wald

发明人： Graham Wiggins ,  Lawrence Wald

IPC分类号： A61B5/05

CPC分类号： A61B5/055 ,  G01R33/288 ,  G01R33/34007 ,  G01R33/34084 ,  G01R33/3415 ,  G01R33/3607 ,  G01R33/365 ,  G01R33/5611 ,  G01R33/5659

摘要： A multi-element MRI head coil is formed in the shape of a helmet that fits over the head of a subject to be imaged. The coil elements are separately driven by rf transmit channels during an MR scan to shape the rf fields produced in the region of interest. The head coil can be used in the transmit only phase of the scan, or it can be used in both the transmit and receive phases.

摘要翻译： 多元素MRI头部线圈形成为头盔的形状，该头盔适合于要被成像的对象的头部。 在MR扫描期间，线圈元件由rf发射通道单独驱动，以形成在感兴趣区域中产生的射频场。 磁头线圈可用于扫描的发射阶段，也可用于发射和接收阶段。

公开(公告)号：US10197646B2

公开(公告)日：2019-02-05

申请号：US14705576

申请日：2015-05-06

申请人： Elfar Adalsteinsson ,  Luca Daniel ,  Bastien Guerin ,  Boris Keil ,  Zohaib Mahmood ,  Markus Vester ,  Lawrence Wald

发明人： Elfar Adalsteinsson ,  Luca Daniel ,  Bastien Guerin ,  Boris Keil ,  Zohaib Mahmood ,  Markus Vester ,  Lawrence Wald

IPC分类号： G01R33/36 ,  G01R33/34 ,  G01R33/385 ,  G01R33/561 ,  G01R33/3415

摘要： A magnetic resonance imaging (MRI) system includes a plurality of transmitters to generate a parallel transmission radio frequency (RF) pulse, an array of coils coupled to the plurality of transmitters to apply the parallel transmission RF pulse to a subject, and a decoupling system connected to the plurality of transmitters and the array of coils. The decoupling system includes a plurality of hybrid couplers, each hybrid coupler of the plurality of hybrid couplers being coupled to a respective pair of the plurality of transmitters and to a respective pair of the array of coils. The plurality of hybrid couplers are configured to diagonalize an impedance matrix of the plurality of coils.

公开(公告)号：US08831703B2

公开(公告)日：2014-09-09

申请号：US11977153

申请日：2007-10-23

申请人： Andre van der Kouwe ,  Bruce Fischl ,  Lawrence Wald

发明人： Andre van der Kouwe ,  Bruce Fischl ,  Lawrence Wald

IPC分类号： A61B5/05 ,  G01R33/56 ,  A61B5/055 ,  G01R33/3415 ,  G01R33/54

CPC分类号： A61B5/055 ,  A61B5/0037 ,  G01R33/3415 ,  G01R33/543 ,  G01R33/56 ,  G01R33/5608

摘要： A system and method for performing an MRI or MRS scan that is optimized for a particular target structure. A prescan is conducted during a first session in which an image that is optimized for segmentation is acquired along with an alignment scout image or a 2D or 3D navigator signal. The segmentation process is employed to locate and define the target structure. During a second session the alignment scout image or navigator signal is reacquired and the information is used to determine the position transformation needed to align images from the two sessions. The position transformation information and the segmentation information are then employed to tailor a prescribed pulse sequence to examine the target structure.

摘要翻译： 用于执行针对特定目标结构优化的MRI或MRS扫描的系统和方法。 在第一会话期间进行预扫描，其中针对分割被优化的图像与对准侦察图像或2D或3D导航信号一起被获取。 采用分割过程来定位和定义目标结构。 在第二次会话期间，重新获取对准侦察图像或导航信号，并且使用该信息来确定对准来自两个会话的图像所需的位置变换。 然后使用位置变换信息和分割信息来定制规定的脉冲序列以检查目标结构。

公开(公告)号：US20130187650A1

公开(公告)日：2013-07-25

申请号：US13355937

申请日：2012-01-23

申请人： Josef Pfeuffer ,  Lawrence Wald

发明人： Josef Pfeuffer ,  Lawrence Wald

IPC分类号： G01R33/565 ,  G01R33/3415

CPC分类号： G01R33/243 ,  G01R33/4616 ,  G01R33/4835 ,  G01R33/5616 ,  G01R33/56563

摘要： In a method for calculating a B0 field map (a map of the basic magnetic field) in a magnetic resonance apparatus, a navigator pulse is emitted and navigator response resulting from the navigator pulse are detected in at least some channels of a multichannel RF coil array. Each channel of the multichannel RF coil array includes an RF coil and spatial information regarding the respective positions of the individual RF coils is made available to a processor, together with the multiple navigator signals. Using the spatial information obtained from the position of the RF coils that respectively detected the navigator response signals, a B0 field map is generated, without the need for spatial encoding the respective navigator response signals.

摘要翻译： 在用于计算磁共振装置中的B0场映射（基本磁场的映射）的方法中，发射导航脉冲，并且在多通道RF线圈阵列的至少一些通道中检测由导航脉冲导致的导航器响应 。 多通道RF线圈阵列的每个通道包括RF线圈，并且关于各个RF线圈的相应位置的空间信息与多个导航器信号一起可用于处理器。 使用从分别检测到导航器响应信号的RF线圈的位置获得的空间信息，生成B0场映射，而不需要对各个导航器响应信号进行空间编码。

公开(公告)号：US20100066361A1

公开(公告)日：2010-03-18

申请号：US12422017

申请日：2009-04-10

申请人： Kawin Setsompop ,  Elfar Adalsteinsson ,  Vijayanand Alagappan ,  Lawrence Wald

发明人： Kawin Setsompop ,  Elfar Adalsteinsson ,  Vijayanand Alagappan ,  Lawrence Wald

IPC分类号： G01R33/48

CPC分类号： G01R33/583 ,  G01R33/246 ,  G01R33/3415 ,  G01R33/5611

摘要： A system and method for producing an image indicative of characteristics of a radiofrequency (“RF”) coil with a magnetic resonance imaging (“MRI”) system is disclosed. The method includes acquiring MR signals while performing a pulse sequence with the MRI system and driving the RF coil at a selected transmission power. This process is repeated a plurality of times to drive the RF coil at a different transmission powers during each repetition. A plurality of images are reconstructed from the acquired MR signals and an image indicative of RF reception characteristics of the RF coil is produced from the reconstructed images. Subsequently, an image indicative of RF transmission characteristics of the RF coil is produced using the image indicative of the RF receiver response. More specifically, only one data acquisition is necessary for each RF coil element to produce the image indicative of the RF transmission characteristics for that coil element.

摘要翻译： 公开了一种用于产生表示具有磁共振成像（“MRI”）系统的射频（“RF”）线圈的特性的图像的系统和方法。 该方法包括在用MRI系统执行脉冲序列并以选定的发射功率驱动RF线圈的同时获取MR信号。 该过程重复多次以在每次重复期间以不同的发送功率驱动RF线圈。 从所获取的MR信号重建多个图像，并且从重建图像产生表示RF线圈的RF接收特性的图像。 随后，使用表示RF接收机响应的图像来产生指示RF线圈的RF传输特性的图像。 更具体地，对于每个RF线圈元件仅需要一个数据采集来产生指示该线圈元件的RF传输特性的图像。

公开(公告)号：US20080103383A1

公开(公告)日：2008-05-01

申请号：US11977153

申请日：2007-10-23

申请人： Andre van der Kouwe ,  Bruce Fischl ,  Lawrence Wald

发明人： Andre van der Kouwe ,  Bruce Fischl ,  Lawrence Wald

IPC分类号： A61B5/055

CPC分类号： A61B5/055 ,  A61B5/0037 ,  G01R33/3415 ,  G01R33/543 ,  G01R33/56 ,  G01R33/5608

摘要： A system and method for performing an MRI or MRS scan that is optimized for a particular target structure. A prescan is conducted during a first session in which an image that is optimized for segmentation is acquired along with an alignment scout image or a 2D or 3D navigator signal. The segmentation process is employed to locate and define the target structure. During a second session the alignment scout image or navigator signal is reacquired and the information is used to determine the position transformation needed to align images from the two sessions. The position transformation information and the segmentation information are then employed to tailor a prescribed pulse sequence to examine the target structure.

摘要翻译： 用于执行针对特定目标结构优化的MRI或MRS扫描的系统和方法。 在第一会话期间进行预扫描，其中针对分割被优化的图像与对准侦察图像或2D或3D导航信号一起被获取。 采用分割过程来定位和定义目标结构。 在第二次会话期间，重新获取对准侦察图像或导航信号，并且使用该信息来确定对准来自两个会话的图像所需的位置变换。 然后使用位置变换信息和分割信息来定制规定的脉冲序列以检查目标结构。

公开(公告)号：US20150323623A1

公开(公告)日：2015-11-12

申请号：US14705576

申请日：2015-05-06

申请人： Elfar Adalsteinsson ,  Luca Daniel ,  Bastien Guerin ,  Boris Keil ,  Zohaib Mahmood ,  Markus Vester ,  Lawrence Wald

发明人： Elfar Adalsteinsson ,  Luca Daniel ,  Bastien Guerin ,  Boris Keil ,  Zohaib Mahmood ,  Markus Vester ,  Lawrence Wald

IPC分类号： G01R33/36 ,  G01R33/385 ,  G01R33/561 ,  G01R33/34

CPC分类号： G01R33/365 ,  G01R33/34076 ,  G01R33/34092 ,  G01R33/3415 ,  G01R33/3657 ,  G01R33/385 ,  G01R33/5612

摘要： A magnetic resonance imaging (MRI) system includes a plurality of transmitters to generate a parallel transmission radio frequency (RF) pulse, an array of coils coupled to the plurality of transmitters to apply the parallel transmission RF pulse to a subject, and a decoupling system connected to the plurality of transmitters and the array of coils. The decoupling system includes a plurality of hybrid couplers, each hybrid coupler of the plurality of hybrid couplers being coupled to a respective pair of the plurality of transmitters and to a respective pair of the array of coils. The plurality of hybrid couplers are configured to diagonalize an impedance matrix of the plurality of coils.

摘要翻译： 磁共振成像（MRI）系统包括多个发射器以产生并行传输射频（RF）脉冲，耦合到多个发射器的线圈阵列以将并行发射RF脉冲施加到对象，以及解耦系统 连接到多个发射器和线圈阵列。 解耦系统包括多个混合耦合器，多个混合耦合器的每个混合耦合器耦合到相应的多个发射器对以及相应的一对线圈阵列。 多个混合耦合器被配置为使多个线圈的阻抗矩阵对角化。