公开(公告)号：US06586935B1

公开(公告)日：2003-07-01

申请号：US09540820

申请日：2000-03-31

申请人： Jingfei Ma ,  Richard Scott Hinks ,  Kevin F. King ,  Graeme C. McKinnon

发明人： Jingfei Ma ,  Richard Scott Hinks ,  Kevin F. King ,  Graeme C. McKinnon

IPC分类号： G01V300

CPC分类号： G01R33/565 ,  G01R33/56563

摘要： A technique is provided for characterizing and correcting for instabilities or variations in a magnet system of an MRI scanner. The technique makes use of a navigator pulse to read out navigator echo data in the absence of phase encode, or with phase encode effects rewound. The navigator data is used to characterize several potential effects of magnet system instabilities or variations, such as zeroth order phase shifts, first order (linear) phase shifts, bulk position shifts, and amplitude effects. The effects of the instabilities can be used, then, to correct image data acquired during an examination.

摘要翻译： 提供了用于表征和校正MRI扫描仪的磁体系统中的不稳定性或变化的技术。 该技术利用导航脉冲在没有相位编码的情况下读出导航回波数据，或者相位编码效果被重绕。 导航数据用于表征磁体系统不稳定性或变化的若干潜在影响，例如零级相移，一阶（线性）相移，体积位移和幅度效应。 可以使用不稳定性的影响，然后校正在检查期间获取的图像数据。

公开(公告)号：US06486671B1

公开(公告)日：2002-11-26

申请号：US09855105

申请日：2001-05-14

申请人： Kevin F. King

发明人： Kevin F. King

IPC分类号： G01V300

CPC分类号： G01R33/3415 ,  G01R33/56545

摘要： A method and apparatus for increasing the signal-to-noise ratio in a magnetic resonance image generated with a system including at least two receiver coils where the data acquisition period is reduced by increasing the space between k-space raster data rows such that image wrapping occurs and an unwrapping algorithm is required, the method including identifying a sensitivities matrix corresponding to the receiver coils, acquiring NMR signals and converting those signals to image pixel intensities, defining a correction matrix, altering the sensitivities matrix as a function of the correction matrix, combining the altered sensitivities matrix and the intensity matrix to generate an estimated spin density matrix and using a spin density matrix to generate the final image.

摘要翻译： 一种用于增加由包括至少两个接收器线圈的系统产生的磁共振图像中的信噪比的方法和装置，其中数据采集周期通过增加k空间光栅数据行之间的空间而减小，使得图像包裹 发生并且需要展开算法，所述方法包括识别对应于接收器线圈的灵敏度矩阵，获取NMR信号并将这些信号转换成图像像素强度，定义校正矩阵，将灵敏度矩阵改变为校正矩阵的函数， 组合改变的灵敏度矩阵和强度矩阵以产生估计的自旋密度矩阵并使用自旋密度矩阵来生成最终图像。

公开(公告)号：US06466017B1

公开(公告)日：2002-10-15

申请号：US09453274

申请日：1999-12-02

申请人： Alexander Ganin ,  Kevin F. King

发明人： Alexander Ganin ,  Kevin F. King

IPC分类号： G01V300

CPC分类号： G01R33/482

摘要： A magnetic resonance imaging system has a primary set of whole-body gradient coils and a supplemental set of gradient coils. The supplemental gradient coils are employed to produce imaging gradients when fast imaging pulse sequences are performed, and the primary set of gradient coils are employed when interleaved saturation or navigator signals pulse sequences are performed during a scan.

摘要翻译： 磁共振成像系统具有一组全身梯度线圈和一组补充梯度线圈。 当执行快速成像脉冲序列时，补充梯度线圈用于产生成像梯度，并且当在扫描期间执行交错饱和度或导航信号脉冲序列时采用梯度线圈的主要集合。

公开(公告)号：US6067465A

公开(公告)日：2000-05-23

申请号：US980192

申请日：1997-11-26

申请人： Thomas K. F. Foo ,  Kevin F. King

发明人： Thomas K. F. Foo ,  Kevin F. King

IPC分类号： G01R33/565 ,  A61B5/055

CPC分类号： G01R33/56509

摘要： A fast and computationally efficient system and method is disclosed for detecting and tracking the position of a reference structure in the body using a linear phase shift to minimize motion artifacts in magnetic resonance imaging. In one application, the system and method is used to determine the relative position of the diaphragm in the body in order to synchronize data acquisition to the same relative position with respect to the abdominal and thoracic organs to minimize respiratory motion artifacts. The system and method uses the time domain linear phase shift of the reference structure data in order to determine its spatial positional displacement as a function of the respiratory cycle. The signal from a two-dimensional rectangular or cylindrical column is first Fourier transformed to the image domain, apodized or bandwidth-limited, converted to real, positive values by taking the magnitude of the profile, and then transformed back to the image domain. The relative displacement of a target edge in the image domain is determined from an auto-correlation of the resulting time domain information.

摘要翻译： 公开了一种快速和计算有效的系统和方法，用于使用线性相移来检测和跟踪身体中参考结构的位置，以最小化磁共振成像中的运动伪影。 在一个应用中，系统和方法用于确定隔膜在体内的相对位置，以便将数据采集同步到与腹部和胸部器官相同的相对位置，以最小化呼吸运动伪像。 该系统和方法使用参考结构数据的时域线性相移，以便确定其作为呼吸周期的函数的空间位置位移。 来自二维矩形或圆柱列的信号首先被傅里叶变换到图像域，通过取样或者带宽限制，通过取轮廓的幅度转换为实数正值，然后转换回图像域。 根据所得到的时域信息的自相关来确定图像域中的目标边缘的相对位移。

公开(公告)号：US5998996A

公开(公告)日：1999-12-07

申请号：US826183

申请日：1997-03-27

申请人： Matthew A. Bernstein ,  Xiaohang Zhou ,  Kevin F. King ,  Alexander Ganin ,  Gary H. Glover ,  Norbert J. Pelc ,  Jason A. Polzin

发明人： Matthew A. Bernstein ,  Xiaohang Zhou ,  Kevin F. King ,  Alexander Ganin ,  Gary H. Glover ,  Norbert J. Pelc ,  Jason A. Polzin

IPC分类号： G01R33/54 ,  A61B5/055 ,  G01R33/563 ,  G01R33/565 ,  G01V3/00

CPC分类号： G01R33/56581 ,  G01R33/56308

摘要： A method is presented for correcting Maxwell term error artifacts produced by an NMR system during the production of either a phase contrast angiogram or a complex difference angiogram. Phase corrections are made to the reconstructed phase image to eliminate the artifacts. Correction coefficients calculated from the flow encoding magnetic gradient waveforms of the phase contrast pulse sequence are used in a polynomial to calculate a set of phase error corrections. These corrections are then used to adjust the phase at each pixel of the angiogram image.

摘要翻译： 提出了一种用于在生产相位对比血管造影或复杂差异血管造影图中校正由NMR系统产生的麦克斯韦尔术语误差伪像的方法。 对重建的相位图像进行相位校正，以消除伪影。 由相位对比脉冲序列的流量编码磁梯度波形计算的校正系数用于多项式以计算一组相位误差校正。 然后使用这些校正来调整血管造影图像的每个像素处的相位。

公开(公告)号：US5216601A

公开(公告)日：1993-06-01

申请号：US440530

申请日：1989-11-22

申请人： Carl R. Crawford ,  Kevin F. King

发明人： Carl R. Crawford ,  Kevin F. King

IPC分类号： A61B6/03 ,  G06T11/00

CPC分类号： G06T11/005 ,  A61B6/027

摘要： A method of reducing image artifacts in images acquired with fan beam, helical scanning, tomographic imaging systems rebins the fan beam data into parallel beam projection sets. Data is spliced from first areas of the parallel beam projection data to second areas to create a set of 2.pi. radians of complete projection data. The 2.pi. of projection data is divided into half scans which are interpolated and extrapolated to produce a new projection set at the slice plane with reduced helical offset error. A feathering function is used to blend the discontinuities in the interpolation and extrapolation weights to prevent streak image artifacts.

公开(公告)号：US08274286B2

公开(公告)日：2012-09-25

申请号：US12860272

申请日：2010-08-20

申请人： Kevin M. Koch ,  Kevin F. King ,  Graeme C. McKinnon ,  Brian Hargreaves

发明人： Kevin M. Koch ,  Kevin F. King ,  Graeme C. McKinnon ,  Brian Hargreaves

IPC分类号： G01V3/00

CPC分类号： G01R33/56563 ,  G01R33/243 ,  G01R33/4822 ,  G01R33/5608

摘要： A system and method for multi-spectral MR imaging near metal include a computer programmed to calculate an MR pulse sequence comprising a plurality of RF pulses configured to excite spins in an imaging object and comprising a plurality of volume selection gradients and determine a plurality of distinct offset frequency values. For each respective determined offset frequency value, the computer is programmed to execute the MR pulse sequence having a central transmit frequency and a central receive frequency of the MR pulse sequence set to the respective determined offset frequency value. The computer is also programmed to acquire a three-dimensional (3D) MR data set for each MR pulse sequence execution and generate a composite image based on data from each of the acquired 3D MR data sets.

摘要翻译： 用于金属附近的多光谱MR成像的系统和方法包括被编程为计算MR脉冲序列的计算机，该计算机包括被配置为激励成像对象中的自旋的多个RF脉冲，并且包括多个体积选择梯度并且确定多个不同的 偏移频率值。 对于每个相应确定的偏移频率值，计算机被编程为执行MR脉冲序列，该MR脉冲序列具有被设置为相应确定的偏移频率值的MR脉冲序列的中心发射频率和中心接收频率。 计算机还被编程为获取每个MR脉冲序列执行的三维（3D）MR数据集，并且基于来自每个获取的3D MR数据集的数据生成合成图像。

公开(公告)号：US07592808B1

公开(公告)日：2009-09-22

申请号：US12115786

申请日：2008-05-06

申请人： Kevin F. King

发明人： Kevin F. King

IPC分类号： G01V3/00

CPC分类号： G01R33/56545 ,  G01R33/561

摘要： A system and method for reducing the scan time of an MR imaging system using a data acquisition technique that combines partial Fourier acquisition and compressed sensing includes a computer programmed to acquire a partial MR data set in k-space along a phase encoding direction, the data set having missing data in the phase encoding direction due to the omission of phase encoding steps. The computer is further programmed to generate an estimate of a reconstructed image, compensate the partial MR data set for the missing data, and reconstruct an MR image by iteratively minimizing the total squared difference between the k-space data of the estimate of the reconstructed image and the measured k-space data of the compensated partial MR data set.

摘要翻译： 使用组合部分傅立叶获取和压缩感测的数据采集技术来减少MR成像系统的扫描时间的系统和方法包括被编程为沿着相位编码方向在k空间中获取部分MR数据集的计算机，数据 由于缺少相位编码步骤，在相位编码方向上设置有丢失的数据。 计算机还被编程为生成重建图像的估计，补偿缺失数据的部分MR数据集，并且通过迭代地最小化重构图像的估计的k空间数据之间的总平方差来重构MR图像 以及经补偿的部分MR数据集的测量的k空间数据。

公开(公告)号：US20090184711A1

公开(公告)日：2009-07-23

申请号：US12016331

申请日：2008-01-18

申请人： Kevin M, Koch ,  Kevin F. King ,  Reed F. Busse

发明人： Kevin M, Koch ,  Kevin F. King ,  Reed F. Busse

IPC分类号： G01R33/54

CPC分类号： G01R33/243 ,  G01R33/4822 ,  G01R33/5608 ,  G01R33/56563

摘要： An apparatus and method for MR imaging in inhomogeneous magnetic fields includes acquisition of a plurality of three-dimensional (3D) MR data sets, each data set having a central transmit frequency and a central receive frequency set to a frequency offset that is distinct for each 3D MR data set. A composite image is generated based on the plurality of 3D MR data sets.

摘要翻译： 用于不均匀磁场中的MR成像的装置和方法包括获取多个三维（MR）MR数据集，每个数据集具有中心发射频率和中心接收频率，该频率偏移设定为每个 3D MR数据集。 基于多个3D MR数据集生成合成图像。

公开(公告)号：US07466131B1

公开(公告)日：2008-12-16

申请号：US11738225

申请日：2007-04-20

申请人： Dan Xu ,  Kevin F. King ,  Zhi-Pei Liang

发明人： Dan Xu ,  Kevin F. King ,  Zhi-Pei Liang

IPC分类号： G01V3/00

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

摘要： A system and method are provided for designing RF pulses for multi-channel and/or multi-dimensional spatially-selective applications using a linear approximation. Embodiments of the system and method may use a generalized linear-class large tip angle approximation to design RF pulses for multi-channel and parallel transmission. Further, some of these approximations allow for the design of arbitrarily large flip angles, irregularly-shaped flip angle profiles, or arbitrary initial magnetization values. Embodiments of the system and method may also provide for the design of k-space trajectories which aid in maintaining assumptions of the various linear class approximations.

摘要翻译： 提供了一种系统和方法，用于使用线性近似来设计用于多通道和/或多维空间选择性应用的RF脉冲。 该系统和方法的实施例可以使用广义线性级大尖角近似来设计用于多通道和并行传输的RF脉冲。 此外，这些近似中的一些允许设计任意大的翻转角，不规则形状的翻转轮廓或任意的初始磁化值。 系统和方法的实施例还可以提供有助于维持各种线性类近似的假设的k空间轨迹的设计。