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    System and method for parallel magnetic resonance image reconstruction using digital beamforming
    2.
    发明授权
    System and method for parallel magnetic resonance image reconstruction using digital beamforming 有权
    使用数字波束成形的并行磁共振图像重建的系统和方法

    公开(公告)号：US09360543B2

    公开(公告)日：2016-06-07

    申请号：US13866735

    申请日：2013-04-19

    申请人： Anand Gopinath ,  Emad S. Ebbini ,  John Thomas Vaughan ,  Lance DelaBarre

    发明人： Anand Gopinath ,  Emad S. Ebbini ,  John Thomas Vaughan ,  Lance DelaBarre

    IPC分类号： G01V3/00 ,  G01R33/56 ,  G01R33/3415

    CPC分类号： G01R33/56 ,  G01R33/3415 ,  G01R33/5608

    摘要： Systems and methods for beamforming algorithms for transmit-receive parallel magnetic resonance imaging (“pMRI”) applications are described. For any transmit configuration (e.g., using a single or multiple transmit elements) a weighted sum of the complex image data from each receiver is formed with a spatially-varying weighting. The weighting factor is obtained by solving an optimal refocusing problem at a set of points in the image space, which can include all the pixels in the image. The optimal refocusing of the transmit-receive configuration accounts for the spatially-varying SNR in deriving the coefficients of the weighted sum at every image pixel.

    摘要翻译： 描述了用于发射 - 接收并行磁共振成像（“pMRI”）应用的波束成形算法的系统和方法。 对于任何发送配置（例如，使用单个或多个发射元件），来自每个接收机的复数图像数据的加权和由空间变化的加权形成。 通过在图像空间中的一组点处求解最优重聚焦问题来获得加权因子，其可以包括图像中的所有像素。 发送接收配置的最优重新聚焦在导出每个图像像素处的加权和的系数时考虑空间变化的SNR。

    Method and system for NMR using adiabatic RF pulses producing spatially quadratic phase
    4.
    发明授权
    Method and system for NMR using adiabatic RF pulses producing spatially quadratic phase 有权
    NMR的方法和系统使用绝热RF脉冲产生空间二次相

    公开(公告)号：US06650116B2

    公开(公告)日：2003-11-18

    申请号：US09961502

    申请日：2001-09-24

    申请人： Michael G. Garwood ,  Kamil Ugurbil ,  Lance DelaBarre ,  Patrick Bolan

    发明人： Michael G. Garwood ,  Kamil Ugurbil ,  Lance DelaBarre ,  Patrick Bolan

    IPC分类号： G01V300

    CPC分类号： G01R33/4616 ,  G01R33/483

    摘要： A method and system for performing MRI and NMR spectroscopy that improves the dynamic range of the received signal by using adiabatic RF pulses for spin excitation rather than for spin inversion. The preferred adiabatic RF excitation produces a spatially varying phase across the slab, and a sharp slab profile. The phase variation is divided up by a phase-encoding gradient into voxels having a phase variation that is negligible over the width of the voxel. The phase variation in the slab-select direction is, on the whole, large enough that the peak amplitude of the received signal is reduced and the signal width broadened. This reduces the dynamic range required of the analog to digital converter used in a NMR system. A NMR system suitable for carrying out the methods of the invention is also disclosed.

    摘要翻译： 用于执行MRI和NMR光谱的方法和系统，其通过使用绝热RF脉冲进行自旋激励而不是自旋反转来改善接收信号的动态范围。 优选的绝热RF激发产生横跨板坯的空间变化的相位，并且产生锋利的板坯轮廓。 相位变化通过相位编码梯度被划分成具有在体素的宽度上可忽略的相位变化的体素。 平板选择方向的相位变化总体上足够大，使得接收信号的峰值幅度减小并且信号宽度变宽。 这降低了在NMR系统中使用的模数转换器所需的动态范围。 还公开了适用于实施本发明方法的NMR系统。

    System and Method for Parallel Magnetic Resonance Image Reconstruction Using Digital Beamforming
    5.
    发明申请
    System and Method for Parallel Magnetic Resonance Image Reconstruction Using Digital Beamforming 有权
    使用数字波束成形的并行磁共振图像重建的系统和方法

    公开(公告)号：US20130278260A1

    公开(公告)日：2013-10-24

    申请号：US13866735

    申请日：2013-04-19

    申请人： Anand Gopinath ,  Emad S. Ebbini ,  John Thomas Vaughan ,  Lance DelaBarre

    发明人： Anand Gopinath ,  Emad S. Ebbini ,  John Thomas Vaughan ,  Lance DelaBarre

    IPC分类号： G01R33/56

    CPC分类号： G01R33/56 ,  G01R33/3415 ,  G01R33/5608

    摘要： Systems and methods for beamforming algorithms for transmit-receive parallel magnetic resonance imaging (“pMRI”) applications are described. For any transmit configuration (e.g., using a single or multiple transmit elements) a weighted sum of the complex image data from each receiver is formed with a spatially-varying weighting. The weighting factor is obtained by solving an optimal refocusing problem at a set of points in the image space, which can include all the pixels in the image. The optimal refocusing of the transmit-receive configuration accounts for the spatially-varying SNR in deriving the coefficients of the weighted sum at every image pixel.

    摘要翻译： 描述了用于发射 - 接收并行磁共振成像（“pMRI”）应用的波束成形算法的系统和方法。 对于任何发送配置（例如，使用单个或多个发射元件），来自每个接收机的复数图像数据的加权和由空间变化的加权形成。 通过在图像空间中的一组点处求解最优重聚焦问题来获得加权因子，其可以包括图像中的所有像素。 发送接收配置的最优重新聚焦在导出每个图像像素处的加权和的系数时考虑空间变化的SNR。

    Adiabatic radiofrequency pulse schemes for use in performing nuclear magnetic resonance spectroscopy
    8.
    发明申请
    Adiabatic radiofrequency pulse schemes for use in performing nuclear magnetic resonance spectroscopy 审中-公开
    用于执行核磁共振光谱的绝热射频脉冲方案

    公开(公告)号：US20050024052A1

    公开(公告)日：2005-02-03

    申请号：US10882554

    申请日：2004-06-30

    申请人： M. Bendall ,  Lance DelaBarre ,  Michael Garwood

    发明人： M. Bendall ,  Lance DelaBarre ,  Michael Garwood

    IPC分类号： G01R33/46 ,  G01V3/00

    CPC分类号： G01R33/4616

    摘要： Adiabatic radiofrequency (RF) pulses are commonly used in nuclear magnetic resonance spectroscopy and imaging. Adiabatic half passage (AHP) pulses show increased non-ideal behavior with respect to adiabatic full passage pulses. The invention is a method of analysis of the initial and final states existing at the beginning and end of an AHP pulse which shows that this non-ideal behavior arises from these initial and final states. In a first embodiment of the invention, a method is obtained to allow forward AHP pulses to be used as selective RF pulses in selective NMR spectroscopy. In a second embodiment of the invention, a method called “an amplitude ramp” is added to an AHP pulse to increase the effective bandwidth of the AHP pulse. In a third embodiment of the invention, a method called “a frequency offset ramp” is added to an AHP pulse to eliminate Gibbs truncation artifacts generated by the truncation of the RF amplitude modulation function used in the AHP pulse. In a fourth embodiment, a time delay is added asymmetrically to four consecutive AHP pulses (also known as a BIR-4 scheme) to produce a chemical shift correlation sub-sequence of RF pulses for use in multi-dimensional NMR.

    摘要翻译： 绝热射频（RF）脉冲通常用于核磁共振光谱和成像。 绝热半通道（AHP）脉冲显示相对于绝热全通道脉冲增加的非理想行为。 本发明是分析存在于AHP脉冲的开始和结束处的初始状态和最终状态的方法，其显示出这种非理想行为源于这些初始状态和最终状态。 在本发明的第一实施例中，获得了一种方法，以允许在选择性NMR光谱中使用正向AHP脉冲作为选择性RF脉冲。 在本发明的第二实施例中，将一种称为“幅度斜坡”的方法添加到AHP脉冲以增加AHP脉冲的有效带宽。 在本发明的第三实施例中，将一种称为“频率偏移斜坡”的方法添加到AHP脉冲，以消除通过截断在AHP脉冲中使用的RF幅度调制函数而产生的吉布斯截断伪影。 在第四实施例中，对四个连续的AHP脉冲（也称为BIR-4方案）不均匀地加上时间延迟，以产生用于多维NMR的RF脉冲的化学位移相关子序列。