公开(公告)号：US20090284257A1

公开(公告)日：2009-11-19

申请号：US12454530

申请日：2009-05-18

申请人： Roland Bammer ,  Murat Aksoy

发明人： Roland Bammer ,  Murat Aksoy

IPC分类号： G01R33/20

CPC分类号： G01R33/56341 ,  G01R33/56509

摘要： In tensor MRI, a set of k-space MRI data points is acquired that includes one or more k-space subsets of MRI data points. An object orientation (or spatial transformation) corresponding to each of the k-space subsets is determined. Because the object orientation (or spatial transformation) can differ from subset to subset, the overall set of k-space data can be inconsistent with respect to object orientation (or spatial transformation). This possible inconsistency can be addressed by providing a k-space tensor model that includes object orientation and/or spatial transformation information corresponding to each of the subsets. A tensor MRI image can be reconstructed from the set of k-space MRI data points by using the k-space tensor model to account for object orientation and/or spatial transformation.

摘要翻译： 在张量MRI中，获取包括MRI数据点的一个或多个k空间子集的一组k空间MRI数据点。 确定对应于每个k-空间子集的对象取向（或空间变换）。 由于对象方向（或空间变换）可以从子集到子集不同，所以k空间数据的整体集可以与对象取向（或空间变换）不一致。 可以通过提供包括与每个子集相对应的对象取向和/或空间变换信息的k空间张量模型来解决这种可能的不一致性。 可以通过使用k空间张量模型来考虑物体取向和/或空间变换，从该组k空间MRI数据点重建张量MRI图像。

公开(公告)号：US07348776B1

公开(公告)日：2008-03-25

申请号：US11469617

申请日：2006-09-01

申请人： Murat Aksoy ,  Chunlei Liu ,  Rexford Newbould ,  Roland Bammer

发明人： Murat Aksoy ,  Chunlei Liu ,  Rexford Newbould ,  Roland Bammer

IPC分类号： G01V3/00

CPC分类号： G01R33/5611 ,  G01R33/56509 ,  G01R33/5676

摘要： A method of correcting for motion in magnetic resonance images of an object detected by a plurality of signal receiver coils comprising the steps of acquiring a plurality of image signals with the plurality of receiver coils, determining motion between sequential image signals relative to a reference, applying rotation and translation to image signals to align image signals with the reference, determining altered coil sensitivities due to object movement during image signal acquisition, and employing parallel imaging reconstruction of the rotated and translated image signals using the altered coil sensitivities in order to compensate for undersampling in k-space.

摘要翻译： 一种校正由多个信号接收器线圈检测的对象的磁共振图像中的运动的方法，包括以下步骤：利用所述多个接收器线圈获取多个图像信号，确定相对于参考的顺序图像信号之间的运动，应用 旋转和平移到图像信号以使图像信号与参考对准，确定在图像信号采集期间由于物体移动引起的线圈灵敏度变化，并且使用改变的线圈灵敏度采用旋转和平移的图像信号的并行成像重建，以补偿欠采样 在k空间。

公开(公告)号：US06969991B2

公开(公告)日：2005-11-29

申请号：US10317516

申请日：2002-12-11

申请人： Roland Bammer ,  Michael Markl ,  Burak Acar ,  Norbert J. Pelc ,  Michael E. Moseley

发明人： Roland Bammer ,  Michael Markl ,  Burak Acar ,  Norbert J. Pelc ,  Michael E. Moseley

IPC分类号： G01R33/563 ,  G01R33/565 ,  G01V3/00

CPC分类号： G01R33/56341 ,  G01R33/56518

摘要： A general mathematical framework is formulated to characterize the contribution of gradient non-uniformities to diffusion tensor imaging in MRI. Based on a model expansion, the actual gradient field is approximated and employed, after elimination of geometric distortions, for predicting and correcting the errors in diffusion encoding. Prior to corrections, experiments clearly reveal marked deviations of the calculated diffusivity for fields of view generally used in diffusion experiments. These deviations are most significant with greater distance from the magnet's isocenter. For a FOV of 25 cm the resultant errors in absolute diffusivity can range from approximately −10 to +20 percent. Within the same field of view, the diffusion-encoding direction and the orientation of the calculated eigenvectors can be significantly altered if the perturbations by the gradient non-uniformities are not considered. With the proposed correction scheme most of the errors introduced by gradient non-uniformities can be removed.

摘要翻译： 制定了一般的数学框架来表征梯度不均匀性对MRI中扩散张量成像的贡献。 基于模型扩展，在消除几何失真之后，实际梯度场被近似和采用，用于预测和纠正扩散编码中的误差。 在更正之前，实验清楚地揭示了通常用于扩散实验的视野的计算的扩散系数的显着偏差。 这些偏差是最重要的，距离磁体的等角点更远。 对于25cm的FOV，绝对扩散率的所得误差可以在约-10至+ 20％的范围内。 在相同视野内，如果不考虑梯度不均匀性的扰动，则可以显着地改变计算的特征向量的扩散编码方向和取向。 利用提出的校正方案，可以消除由梯度不均匀性引入的大多数误差。

公开(公告)号：US08929972B2

公开(公告)日：2015-01-06

申请号：US12798280

申请日：2010-03-31

申请人： Roland Bammer ,  Greg Zaharchuk

发明人： Roland Bammer ,  Greg Zaharchuk

IPC分类号： A61B5/05 ,  G01R33/563

CPC分类号： G01R33/56366

摘要： Arterial spin labeling MRI is used to provide a patient specific correction factor to correct a image provided by a non-ASL imaging modality (e.g., DSC MRI). More specifically, a first blood flow image is taken using the non-ASL imaging modality, and a corresponding second blood flow image is taken with ASL. Some or all of the voxels in the first image are selected according to a predetermined selection method. A correction factor (CF) is computed to be the ratio of second image BF to first image BF averaged over the selected voxels. Thus, CF is the average of ASL/non-ASL blood flow over the selected voxels. This correction factor is applied to all voxels of an image equally, but can differ from patient to patient. This correction can be applied to one or more non-ASL blood flow images.

摘要翻译： 动脉自旋标记MRI用于提供患者特异性校正因子以校正由非ASL成像模态（例如DSC MRI）提供的图像。 更具体地，使用非ASL成像模式拍摄第一血流图像，并且用ASL拍摄相应的第二血流图像。 根据预定的选择方法选择第一图像中的一些或全部体素。 校正因子（CF）被计算为在所选择的体素上平均的第二图像BF与第一图像BF的比率。 因此，CF是所选体素中ASL /非ASL血流量的平均值。 该校正因子被均匀地应用于图像的所有体素，但是可以在患者与患者之间不同。 该校正可以应用于一个或多个非ASL血流图像。

公开(公告)号：US20070182411A1

公开(公告)日：2007-08-09

申请号：US11348852

申请日：2006-02-06

申请人： Roland Bammer ,  Chunlei Liu

发明人： Roland Bammer ,  Chunlei Liu

IPC分类号： G01V3/00

CPC分类号： G01R33/5611 ,  G01R33/4824 ,  G01R33/56308 ,  G01R33/56341 ,  G01R33/56509 ,  G01R33/5676

摘要： Disclosed is an effective algorithm to correct motion-induced phase error using an iterative reconstruction. Using a conjugate-gradient (CG) algorithm, the phase error is treated as an image encoding function. Given the complex perturbation terms, diffusion-weighted images can be reconstructed using an augmented sensitivity map. The mathematical formulation and image reconstruction procedures are similar to the SENSE reconstruction. By defining a dynamic composition sensitivity, the CG phase correction method can be conveniently incorporated with SENSE reconstruction for the application of multi-shot SENSE DWI. Effective phase correction and multi-shot SENSE DWI (R=1 to 3) are demonstrated on both simulated and in vivo data acquired with PROPELLER and SNAILS.

摘要翻译： 公开了一种使用迭代重建来校正运动诱发相位误差的有效算法。 使用共轭梯度（CG）算法，相位误差被视为图像编码功能。 给定复杂的扰动项，扩散加权图像可以使用增强的灵敏度图重建。 数学公式和图像重建程序与SENSE重建相似。 通过定义动态组合灵敏度，CG相位校正方法可以方便地结合SENSE重建用于多镜头SENSE DWI的应用。 在使用PROPELLER和SNAILS获取的模拟和体内数据中都可以证明有效的相位校正和多镜头SENSE DWI（R = 1到3）。

公开(公告)号：US07202662B2

公开(公告)日：2007-04-10

申请号：US10463741

申请日：2003-06-16

申请人： Michael Markl ,  Norbert J. Pelc ,  Roland Bammer

发明人： Michael Markl ,  Norbert J. Pelc ,  Roland Bammer

IPC分类号： G01V3/00

CPC分类号： G01R33/56341 ,  G01R33/56518

摘要： Errors in qualitative phase contrast measurements due to gradient field heterogeneities are reduced by using either a generalized reconstruction algorithm or an approximate reconstruction algorithm. True velocities are calculated using measured velocity information and phase differences, first moments of gradients, and gyromagnetic ratio.

摘要翻译： 通过使用广义重建算法或近似重构算法，减少了由于梯度场异质性引起的定性相位对比度测量的误差。 使用测量的速度信息和相位差，梯度的第一时刻和回旋磁比来计算真实速度。

公开(公告)号：US08848977B2

公开(公告)日：2014-09-30

申请号：US13134703

申请日：2011-06-15

申请人： Roland Bammer ,  Christoph Forman ,  Murat Aksoy

发明人： Roland Bammer ,  Christoph Forman ,  Murat Aksoy

IPC分类号： G06K9/00 ,  G06T7/20 ,  G06T7/00 ,  G06K9/32

CPC分类号： G06K9/3216 ,  G06T7/248 ,  G06T7/74 ,  G06T2207/10081 ,  G06T2207/10088 ,  G06T2207/10104 ,  G06T2207/10108 ,  G06T2207/30016

摘要： The tracking and compensation of patient motion during a magnetic resonance imaging (MRI) acquisition is an unsolved problem. A self-encoded marker where each feature on the pattern is augmented with a 2-D barcode is provided. Hence, the marker can be tracked even if it is not completely visible in the camera image. Furthermore, it offers considerable advantages over a simple checkerboard marker in terms of processing speed, since it makes the correspondence search of feature points and marker-model coordinates, which are required for the pose estimation, redundant. Significantly improved accuracy is obtained for both phantom experiments and in-vivo experiments with substantial patient motion. In an alternative aspect, a marker having non-coplanar features can be employed to provide improved motion tracking. Such a marker provides depth cues that can be exploited to improve motion tracking. The aspects of non-coplanar patterns and self-encoded patterns can be practiced independently or in combination.

摘要翻译： 磁共振成像（MRI）采集期间患者运动的跟踪和补偿是未解决的问题。 提供了一种自编码标记，其中图案上的每个特征都用2-D条形码增加。 因此，即使在相机图像中不完全可见，也可以跟踪标记。 此外，它在处理速度方面比简单的棋盘标记提供了显着的优点，因为它使得姿势估计所需的特征点和标记 - 模型坐标的对应搜索是冗余的。 对于具有实质性的患者运动的虚拟实验和体内实验，获得显着提高的精度。 在另一方面，可以使用具有非共面特征的标记来提供改进的运动跟踪。 这样的标记提供可以利用来提高运动跟踪的深度提示。 非共面图案和自编码图案的方面可以独立地或组合地实现。

公开(公告)号：US20130229177A1

公开(公告)日：2013-09-05

申请号：US13600146

申请日：2012-08-30

申请人： Roland Bammer ,  Anh Tu Van ,  Rafael O'Halloran

发明人： Roland Bammer ,  Anh Tu Van ,  Rafael O'Halloran

IPC分类号： G01R33/56

CPC分类号： G01R33/56 ,  G01R33/5614 ,  G01R33/56341 ,  G01R33/56509 ,  G01R33/5676

摘要： Phase error in MR imaging is corrected in real time by providing adaptive RF pulses and corresponding adaptive magnetic field gradients to mitigate the effect of phase error in the imaging subject. A real time phase error map is obtained, and then adaptive RF pulses and corresponding field gradients are applied that remove the problematic effects of the phase error. Depending on details of the MR imaging mode being employed, there are several ways this removal can be done. Phase error can be cancelled by providing RF pulses that make the phase in the imaging subject uniform. Another approach is to make the adaptive RF pulses insensitive to the phase errors that are present.

摘要翻译： 通过提供自适应RF脉​​冲和相应的自适应磁场梯度来实时地校正MR成像中的相位误差，以减轻成像对象中的相位误差的影响。 获得实时相位误差图，然后应用自适应RF脉​​冲和相应的场梯度，消除相位误差的有问题的影响。 根据所采用的MR成像模式的细节，可以通过几种方式来实现这种移除。 可以通过提供使成像对象中的相位均匀的RF脉冲来消除相位误差。 另一种方法是使自适应RF脉​​冲对存在的相位误差不敏感。

公开(公告)号：US20110245656A1

公开(公告)日：2011-10-06

申请号：US12798280

申请日：2010-03-31

申请人： Roland Bammer ,  Greg Zaharchuk

发明人： Roland Bammer ,  Greg Zaharchuk

IPC分类号： A61B5/055

CPC分类号： G01R33/56366

摘要： Arterial spin labeling MRI is used to provide a patient specific correction factor to correct a image provided by a non-ASL imaging modality (e.g., DSC MRI). More specifically, a first blood flow image is taken using the non-ASL imaging modality, and a corresponding second blood flow image is taken with ASL. Some or all of the voxels in the first image are selected according to a predetermined selection method. A correction factor (CF) is computed to be the ratio of second image BF to first image BF averaged over the selected voxels. Thus, CF is the average of ASL/non-ASL blood flow over the selected voxels. This correction factor is applied to all voxels of an image equally, but can differ from patient to patient. This correction can be applied to one or more non-ASL blood flow images.

摘要翻译： 动脉自旋标记MRI用于提供患者特异性校正因子以校正由非ASL成像模态（例如DSC MRI）提供的图像。 更具体地，使用非ASL成像模式拍摄第一血流图像，并且用ASL拍摄相应的第二血流图像。 根据预定的选择方法选择第一图像中的一些或全部体素。 校正因子（CF）被计算为在所选择的体素上平均的第二图像BF与第一图像BF的比率。 因此，CF是所选体素中ASL /非ASL血流量的平均值。 该校正因子被均匀地应用于图像的所有体素，但是可以在患者与患者之间不同。 该校正可以应用于一个或多个非ASL血流图像。

公开(公告)号：US20090209846A1

公开(公告)日：2009-08-20

申请号：US11823469

申请日：2007-06-26

申请人： Roland Bammer

发明人： Roland Bammer

IPC分类号： A61B5/055 ,  G06K9/00

CPC分类号： A61B5/055 ,  A61B5/064 ,  A61B5/1127 ,  A61B5/7207 ,  G01R33/56308 ,  G01R33/56509 ,  G01R33/5673

摘要： The present invention provides an apparatus and method for real-time motion compensated magnetic resonance imaging (MRI) of a human or animal. The apparatus includes one or more magnetic-resonance compatible cameras mounted on a coil of the MRI device, a calculation and storage device, and an interface operably connected to the MRI device and the calculation and storage device. The apparatus may also include a set of magnetic resonance compatible markers, where the markers are positioned on the human or animal. Alternatively, the apparatus may use a facial recognition algorithm to identify features of the human or animal. For the present invention, the frame of reference is defined by the animal or human being imaged, instead of the typical magnetic resonance coordinate system. Based on continuous positional information, the apparatus controls the magnetic resonance scanner so that it follows the human or animal's motion.

摘要翻译： 本发明提供了一种用于人或动物的实时运动补偿磁共振成像（MRI）的装置和方法。 该装置包括安装在MRI装置的线圈上的一个或多个兼容于磁共振的相机，计算和存储装置以及可操作地连接到MRI装置和计算和存储装置的接口。 该装置还可以包括一组磁共振兼容的标记，其中标记位于人或动物上。 或者，该装置可以使用面部识别算法来识别人或动物的特征。 对于本发明，参考帧由动物或人被成像定义，而不是典型的磁共振坐标系。 基于连续的位置信息，该装置控制磁共振扫描器，使其遵循人或动物的运动。