公开(公告)号：US09336611B2

公开(公告)日：2016-05-10

申请号：US13822102

申请日：2011-09-13

申请人： Berkin Bilgic ,  Elfar Adalsteinsson

发明人： Berkin Bilgic ,  Elfar Adalsteinsson

IPC分类号： G06T7/00 ,  G06T11/00 ,  A61B5/055 ,  A61B5/00 ,  G01R33/561 ,  G01R33/48 ,  G01R33/56 ,  G01R33/563

CPC分类号： G06T11/003 ,  A61B5/055 ,  A61B5/7264 ,  G01R33/4806 ,  G01R33/5602 ,  G01R33/5608 ,  G01R33/561 ,  G01R33/56308 ,  G01R33/56341 ,  G01R33/5635

摘要： A method for reconstructing multiple images of a subject depicting multiple different contrast characteristics from medical image data acquired with a medical imaging system is provided. Multiple image data sets are acquired with one or more medical imaging systems and the image data sets used to estimate hyperparameters drawn from a prior distribution, such as a prior distribution of image gradient coefficients. These hyperparameters and the acquired image data sets are utilized to produce a posterior distribution, such as a posterior distribution of image gradients. From this posterior distribution, multiple images with the different contrast characteristics are reconstructed. The medical imaging system may be a magnetic resonance imaging system, an x-ray computed tomography imaging system, an ultrasound system, and so on.

摘要翻译： 提供了一种用于重建从医学成像系统获取的医学图像数据描绘多个不同对比度特征的被摄体的多个图像的方法。 使用一个或多个医学成像系统和用于估计从先前分布绘制的超参数的图像数据集（诸如图像梯度系数的先前分布）获取多个图像数据集。 这些超参数和所获取的图像数据集被用于产生后验分布，例如图像梯度的后验分布。 从这种后验分布，重建具有不同对比度特征的多个图像。 医学成像系统可以是磁共振成像系统，X射线计算机断层成像系统，超声系统等。

公开(公告)号：US20130188854A1

公开(公告)日：2013-07-25

申请号：US13822102

申请日：2011-09-13

申请人： Berkin Bilgic ,  Elfar Adalsteinsson

发明人： Berkin Bilgic ,  Elfar Adalsteinsson

IPC分类号： G06T11/00

CPC分类号： G06T11/003 ,  A61B5/055 ,  A61B5/7264 ,  G01R33/4806 ,  G01R33/5602 ,  G01R33/5608 ,  G01R33/561 ,  G01R33/56308 ,  G01R33/56341 ,  G01R33/5635

摘要： A method for reconstructing multiple images of a subject depicting multiple different contrast characteristics from medical image data acquired with a medical imaging system is provided. Multiple image data sets are acquired with one or more medical imaging systems and the image data sets used to estimate hyperparameters drawn from a prior distribution, such as a prior distribution of image gradient coefficients. These hyperparameters and the acquired image data sets are utilized to produce a posterior distribution, such as a posterior distribution of image gradients. From this posterior distribution, multiple images with the different contrast characteristics are reconstructed. The medical imaging system may be a magnetic resonance imaging system, an x-ray computed tomography imaging system, an ultrasound system, and so on.

摘要翻译： 提供了一种用于重建从医学成像系统获取的医学图像数据描绘多个不同对比度特征的被摄体的多个图像的方法。 使用一个或多个医学成像系统和用于估计从先前分布绘制的超参数的图像数据集（诸如图像梯度系数的先前分布）获取多个图像数据集。 这些超参数和所获取的图像数据集被用于产生后验分布，例如图像梯度的后验分布。 从这种后验分布，重建具有不同对比度特征的多个图像。 医学成像系统可以是磁共振成像系统，X射线计算机断层成像系统，超声系统等。

公开(公告)号：US20130015854A1

公开(公告)日：2013-01-17

申请号：US13181868

申请日：2011-07-13

申请人： Elfar Adalsteinsson ,  Hans-Peter Fautz ,  Kawin Setsompop ,  Lawrence Wald

发明人： Elfar Adalsteinsson ,  Hans-Peter Fautz ,  Kawin Setsompop ,  Lawrence Wald

IPC分类号： G01R33/44

CPC分类号： G01R33/56563 ,  G01R33/446 ,  G01R33/5607 ,  G01R33/5612 ,  G01R33/5614

摘要： In a magnetic resonance apparatus and operating method therefor, and in a processor that is programmed to design RF pulses for operating such a magnetic resonance apparatus, the RF pulses are designed to mitigate off-resonance effects caused by inhomogeneity of the basic (B0) magnetic field in the magnetic resonance apparatus. The RF pulses of a parallel transmit array are designed with different spatial phase distributions, that deviate from a constant phase from pulse-to-pulse, with the absolute value of the difference between respective spatial phase distributions of any two successively radiated RF pulses corresponding to the off-resonance that is caused by B0-inhomogeneity during the time between the radiation of the successive pulses. Additionally, or separately, currents supplied to the shim coils can be taken into account in the design of the RF pulses as an additional degree of freedom, with the shimming of the basic magnetic field produced by the shim currents deviating from shim currents designed to ideally produce a homogenous B0 field.

摘要翻译： 在一种磁共振装置及其操作方法中，并且在被编程为设计用于操作这种磁共振装置的RF脉冲的处理器中，RF脉冲被设计成减轻由基本（B0）磁性的不均匀性引起的非共振效应 磁场。 平行发射阵列的RF脉冲被设计为具有不同的空间相位分布，其偏离了脉冲到脉冲的恒定相位，对应于任何两个相继辐射的RF脉冲的相应空间相位分布之间的差的绝对值 在连续脉冲的辐射期间由B0不均匀性引起的非共振。 此外，或者单独地，作为附加自由度，在RF脉冲的设计中可以考虑提供给垫片线圈的电流，同时由偏置电流产生的基本磁场的匀场偏离设计成理想的电流 产生均匀的B0场。

公开(公告)号：US20120256626A1

公开(公告)日：2012-10-11

申请号：US13083342

申请日：2011-04-08

申请人： Elfar Adalsteinsson ,  Joonsung Lee ,  Lawrence L. Wald ,  Matthias L. Gebhardt

发明人： Elfar Adalsteinsson ,  Joonsung Lee ,  Lawrence L. Wald ,  Matthias L. Gebhardt

IPC分类号： G01R33/48 ,  G01R33/44

CPC分类号： G01R33/5612 ,  G01R33/288

摘要： A method of designing a parallel transmission radio frequency (RF) pulse for a magnetic resonance imaging (MRI) system includes compressing a model for a subject to be scanned by the MRI system into a plurality of voxel clusters, each voxel cluster defining a virtual observation point with a peak sensitivity to local specific absorption rate (SAR) for the voxel cluster, and defining the parallel transmission RF pulse based on an approximation of a minimization criterion having a local SAR component based on the peak sensitivity of each virtual observation point, the approximation comprising a weighted sum of the local SAR values for each virtual observation point.

摘要翻译： 设计用于磁共振成像（MRI）系统的并行传输射频（RF）脉冲的方法包括将由MRI系统扫描的对象的模型压缩成多个体素簇，每个体素簇定义虚拟观察 点对于体素簇具有对局部比吸收率（SAR）的峰值灵敏度，并且基于基于每个虚拟观测点的峰值灵敏度的具有局部SAR分量的最小化准则的近似来定义并行发射RF脉冲， 近似值包括每个虚拟观测点的局部SAR值的加权和。

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：US07336145B1

公开(公告)日：2008-02-26

申请号：US11599905

申请日：2006-11-15

申请人： Adam Charles Zelinski ,  Elfar Adalsteinsson ,  Kawin Setsompop ,  Lawrence L. Waid ,  Joerg Ulrich Fontius

发明人： Adam Charles Zelinski ,  Elfar Adalsteinsson ,  Kawin Setsompop ,  Lawrence L. Waid ,  Joerg Ulrich Fontius

IPC分类号： G01V3/00

CPC分类号： G01R33/5611 ,  G01R33/288 ,  G01R33/3415 ,  G01R33/5612 ,  G01R33/5659

摘要： Waveforms for radio-frequency (RF) excitations pulses used in magnetic resonance imaging are designed according to a Least Squares QR (LSQR) algorithm or a Conjugate Gradient Least Squares (CGLS) algorithm, to solve the linear system of equations that arises in a multi-channel RF transmit arrangement. Better management of SAR and other factors is achieved with RF pulses designed according to these algorithms, compared to the conventionally employed singular value decomposition (SVD) algorithm.

摘要翻译： 用于磁共振成像的射频（RF）激发脉冲波形根据最小二乘QR（LSQR）算法或共轭梯度最小二乘法（CGLS）算法设计，以求解多重线性方程组的线性系统 通道RF发射布置。 与常规使用的奇异值分解（SVD）算法相比，根据这些算法设计的RF脉冲可以实现SAR和其他因素的更好的管理。

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。

公开(公告)号：US08866478B2

公开(公告)日：2014-10-21

申请号：US13181868

申请日：2011-07-13

申请人： Elfar Adalsteinsson ,  Hans-Peter Fautz ,  Kawin Setsompop ,  Lawrence Wald

发明人： Elfar Adalsteinsson ,  Hans-Peter Fautz ,  Kawin Setsompop ,  Lawrence Wald

IPC分类号： G01V3/00 ,  G01R33/565 ,  G01R33/561 ,  G01R33/56 ,  G01R33/44

CPC分类号： G01R33/56563 ,  G01R33/446 ,  G01R33/5607 ,  G01R33/5612 ,  G01R33/5614

摘要： In a magnetic resonance apparatus and operating method therefor, and in a processor that is programmed to design RF pulses for operating such a magnetic resonance apparatus, the RF pulses are designed to mitigate off-resonance effects caused by inhomogeneity of the basic (B0) magnetic field in the magnetic resonance apparatus. The RF pulses of a parallel transmit array are designed with different spatial phase distributions, that deviate from a constant phase from pulse-to-pulse, with the absolute value of the difference between respective spatial phase distributions of any two successively radiated RF pulses corresponding to the off-resonance that is caused by B0-inhomogeneity during the time between the radiation of the successive pulses. Additionally, or separately, currents supplied to the shim coils can be taken into account in the design of the RF pulses as an additional degree of freedom, with the shimming of the basic magnetic field produced by the shim currents deviating from shim currents designed to ideally produce a homogenous B0 field.

摘要翻译： 在一种磁共振装置及其操作方法中，并且在被编程为设计用于操作这种磁共振装置的RF脉冲的处理器中，RF脉冲被设计成减轻由基本（B0）磁性的不均匀性引起的非共振效应 磁场。 平行发射阵列的RF脉冲被设计为具有不同的空间相位分布，其偏离了脉冲到脉冲的恒定相位，对应于任何两个相继辐射的RF脉冲的相应空间相位分布之间的差的绝对值 在连续脉冲的辐射期间由B0不均匀性引起的非共振。 此外，或者单独地，作为附加自由度，在RF脉冲的设计中可以考虑提供给垫片线圈的电流，同时由偏置电流产生的基本磁场的匀场偏离设计成理想的电流 产生均匀的B0场。

公开(公告)号：US20120146639A1

公开(公告)日：2012-06-14

申请号：US13237799

申请日：2011-09-20

申请人： Alma Gregory Sorensen ,  Ovidiu Cristian Andronesi ,  Carolyn Mountford ,  Saadallah Ramadan ,  Borjan Aleksandar Gagoski ,  Elfar Adalsteinsson

发明人： Alma Gregory Sorensen ,  Ovidiu Cristian Andronesi ,  Carolyn Mountford ,  Saadallah Ramadan ,  Borjan Aleksandar Gagoski ,  Elfar Adalsteinsson

IPC分类号： G01R33/44

CPC分类号： G01R33/4633

摘要： Methods for low-power in vivo localized multi-dimensional correlated magnetic resonance spectroscopy (“MRS”) are provided. Low-power adiabaticity is achieved, generally, using gradient-modulated radio frequency pulses for localization and mixing. The provided pulse sequences also provide a mechanism for longitudinal mixing, which significantly increases the efficiency of magnetization transfer and thereby increases signal-to-noise ratio.

摘要翻译： 提供了低功率体内局部多维相关磁共振光谱法（“MRS”）的方法。 通常使用梯度调制的射频脉冲进行定位和混合，实现了低功率绝热性。 所提供的脉冲序列还提供用于纵向混合的机制，其显着地提高了磁化传递的效率，从而增加了信噪比。

公开(公告)号：US08085044B2

公开(公告)日：2011-12-27

申请号：US12544714

申请日：2009-08-20

申请人： Kawin Setsompop ,  Borjan A. Gagoski ,  Elfar Adalsteinsson ,  Vijayanand Alagappan ,  Lawrence L Wald

发明人： Kawin Setsompop ,  Borjan A. Gagoski ,  Elfar Adalsteinsson ,  Vijayanand Alagappan ,  Lawrence L Wald

IPC分类号： G01V3/00

CPC分类号： G01R33/583 ,  G01R33/246 ,  G01R33/4833 ,  G01R33/485 ,  G01R33/543 ,  G01R33/5612 ,  G01R33/5635 ,  G01R33/56509

摘要： A method for producing a spatially and spectrally selective radiofrequency (“RF”) excitation pulse includes establishing a desired spatial RF excitation pattern and establishing a desired spectral RF excitation pattern. The method also includes estimating an RF transmission profile map indicative of the transmission characteristics of an RF coil and determining, from the desired spatial and spectral excitation patterns and the estimated RF transmission profile map, at least one magnetic field gradient waveform indicative of locations in k-space to which RF energy is to be deposited. The method further includes determining, from the established spatial and spectral excitation patterns, the estimated RF transmission profile map, and the determined at least one gradient waveform, at least one RF excitation pulse waveform that will produce the desired spatial and spectral excitation patterns.

摘要翻译： 用于产生空间和频谱选择性射频（“RF”）激励脉冲的方法包括建立期望的空间RF激励模式并建立期望的频谱RF激励模式。 该方法还包括估计指示RF线圈的传输特性的RF传输分布图，并根据期望的空间和频谱激励模式以及估计的RF传输分布图确定表示k中的位置的至少一个磁场梯度波形 - 空间，RF能量将被放置到该空间。 该方法还包括根据建立的空间和频谱激励模式，确定估计的RF传输概况图和所确定的至少一个梯度波形，至少一个RF激励脉冲波形，其将产生期望的空间和频谱激励模式。