公开(公告)号：US5642047A

公开(公告)日：1997-06-24

申请号：US569617

申请日：1995-12-08

申请人： Matthew A. Bernstein

发明人： Matthew A. Bernstein

IPC分类号： G01R33/565 ,  G01R33/20

CPC分类号： G01R33/56518

摘要： A method for correcting MR data elements acquired in the presence of an imperfectly linear gradient field, each element comprising nominal first and second quadrature components. The quadrature components are multiplied by an artifact correction factor to provide respective first and second quantities. A Gradwarp geometric correction operation is applied to respective quantities to provide a corrected first and second quadrature component, corresponding to each data element. For a given data element, the arctangent function is applied to the result obtained by dividing the first corrected component by the second corrected component to provide a corrected phase component for use in forming an image.

摘要翻译： 一种用于校正在存在不完全线性梯度场获得的MR数据元素的方法，每个元素包括标称的第一和第二正交分量。 正交分量乘以伪像校正因子以提供相应的第一和第二量。 将Gradwarp几何校正操作应用于各个量以提供对应于每个数据元素的校正的第一和第二正交分量。 对于给定的数据元素，反正切函数被应用于通过将第一校正分量除以第二校正分量而获得的结果，以提供用于形成图像的校正相位分量。

公开(公告)号：US07245124B2

公开(公告)日：2007-07-17

申请号：US11341242

申请日：2006-01-27

申请人： Yunhong Shu ,  Matthew A. Bernstein

发明人： Yunhong Shu ,  Matthew A. Bernstein

IPC分类号： G01V3/00

CPC分类号： G01R33/54 ,  G01R33/56509

摘要： A 3D MRI image is acquired as a series of spherical shells of increasing radius. Each shell is sampled by one or more interleaved spiral sampling trajectories and to shorten the scan time one or more spiral sampling trajectories are skipped in the larger shells that sample the periphery of k-space. Motion correction of the acquired k-space data is accomplished by reconstructing tracking images from each of the shells and locating markers therein which indicate object movement from a reference position. The k-space data is corrected using this movement information.

摘要翻译： 获取3D MRI图像作为一系列增加半径的球形壳体。 每个壳体被一个或多个交错螺旋采样轨迹采样，并缩短扫描时间，在较大的壳中跳过一个或多个螺旋取样轨迹，该较大的壳体对k空间的外围进行采样。 所获取的k空间数据的运动校正通过从每个壳体和其中定位标记重建跟踪图像来实现，其中指示物体从参考位置移动。 使用该移动信息来校正k空间数据。

公开(公告)号：US6163152A

公开(公告)日：2000-12-19

申请号：US97525

申请日：1998-06-15

申请人： Matthew A. Bernstein ,  Jason A. Polzin

发明人： Matthew A. Bernstein ,  Jason A. Polzin

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

CPC分类号： G01R33/56518

摘要： A system and method for correcting systematic errors that occur in MR images due to magnetic gradient non-uniformity is disclosed for use with parametric analysis. A GradWarp geometric correction operation is applied in reconstructing quantitative parametric analysis images in regions of gradient non-uniformity. The method includes generating an error map of magnetic gradient strength as a function of distance for an MR image scan and acquiring MR data that contain such systematic errors. The method next includes either calculating a measured diffusion image, a phase difference image, or similar image, based on the acquired MR data, and then calculating a corrected parametric image using the error map and the measured diffusion image, the phase difference image, or other similar parametric image. The method is incorporated into a system having a computer programmed to perform the aforementioned steps and functions.

摘要翻译： 公开了一种用于校正由于磁梯度不均匀性而在MR图像中发生的系统误差的系统和方法，用于参数分析。 应用GradWarp几何校正操作重建梯度不均匀区域的定量参数分析图像。 该方法包括产生磁梯度强度的误差图，作为MR图像扫描的距离的函数，并获取包含这种系统误差的MR数据。 该方法接下来包括基于获取的MR数据计算测量的漫射图像，相位差图像或类似图像，然后使用误差图和测量的漫射图像，相位差图像或 其他类似的参数图像。 该方法被并入具有被编程为执行上述步骤和功能的计算机的系统中。

公开(公告)号：US6011392A

公开(公告)日：2000-01-04

申请号：US5768

申请日：1998-01-12

申请人： Xiaohong Zhou ,  Matthew A. Bernstein ,  Gousheng Tan

发明人： Xiaohong Zhou ,  Matthew A. Bernstein ,  Gousheng Tan

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

CPC分类号： G01R33/56581 ,  G01R33/56554 ,  G01R33/5617

摘要： Fast spin echo pulse sequences are adjusted to reduce, or eliminate image artifacts caused by Maxwell terms arising from the linear imaging gradients. The waveforms of the slice selection, phase encoding and readout gradients are adjusted in shape, size or position to eliminate or reduce the phase error caused by the spatially quadratic Maxwell terms.

摘要翻译： 调整快速自旋回波脉冲序列以减少或消除由线性成像梯度引起的麦克斯韦术引起的图像伪像。 切片选择，相位编码和读出梯度的波形在形状，大小或位置上进行调整，以消除或减少由空间二次Maxwell项引起的相位误差。

公开(公告)号：US5399969A

公开(公告)日：1995-03-21

申请号：US102661

申请日：1993-08-05

申请人： Matthew A. Bernstein

发明人： Matthew A. Bernstein

IPC分类号： G01R33/32 ,  A61B5/055 ,  G01R33/385 ,  G01R33/54 ,  G01V3/00

CPC分类号： G01R33/4833 ,  G01R33/385

摘要： A method for providing an indication of the limits of available functional gradient power when MRI equipment is used to obtain oblique MRI images calculates a "maximum absolute row sum" of a rotational matrix defining the degree obliquity of the image. This maximum absolute row sum provides one or more target functional gradient values based on the limitations of the physical gradients of the system.

摘要翻译： 当MRI设备用于获得倾斜MRI图像时，用于提供可用功能梯度功率限制的指示的方法计算定义图像的度倾斜度的旋转矩阵的“最大绝对行和”。 该最大绝对行总和基于系统的物理梯度的限制提供一个或多个目标函数梯度值。

公开(公告)号：US5170122A

公开(公告)日：1992-12-08

申请号：US735419

申请日：1991-07-25

申请人： Matthew A. Bernstein

发明人： Matthew A. Bernstein

IPC分类号： A61B5/055 ,  G01R33/48 ,  G01R33/561

CPC分类号： G01R33/5613 ,  G01R33/561

摘要： A steady-state free procession fast NMR pulse sequence includes a readout gradient waveform which refocuses the transverse magnetization to produce an S- NMR signal during the subsequent pulse sequence. A partial echo signal acquisition is acquired which enables the pulse sequence to be shortened and enables the S+ NMR signal to be displaced from the data acquisition window without disturbing the flow compensation. View reordering is used in combination with phase cycling to suppress the S+ NMR signal.

公开(公告)号：US20080183067A1

公开(公告)日：2008-07-31

申请号：US12018899

申请日：2008-01-24

申请人： Yunhong Shu ,  Matthew A. Bernstein

发明人： Yunhong Shu ,  Matthew A. Bernstein

IPC分类号： A61B5/055

CPC分类号： G01R33/561 ,  G01R33/4824 ,  G01R33/5635

摘要： A method for prescribing a scan on an MRI system includes selecting a general pulse sequence to be used during a time-resolved imaging process of a subject using an MRI system. The method also includes setting a first set of scan parameters to more specifically prescribe the general pulse sequence and setting a second set of scan parameters using a formula that relates time resolution and spatial resolution resulting from the first set of scan parameters. The method then includes performing the time-resolved imaging process using the general pulse sequence, the first set of scan parameters, and the second set of scan parameters.

摘要翻译： 用于在MRI系统上规定扫描的方法包括选择将在使用MRI系统的对象的时间分辨成像处理期间使用的一般脉冲序列。 该方法还包括设置第一组扫描参数以更具体地规定通用脉冲序列，并使用涉及由第一组扫描参数产生的时间分辨率和空间分辨率的公式来设置第二组扫描参数。 该方法然后包括使用通用脉冲序列，第一组扫描参数和第二组扫描参数执行时间分辨成像处理。

公开(公告)号：US06426623B1

公开(公告)日：2002-07-30

申请号：US09964155

申请日：2001-09-26

申请人： Matthew A. Bernstein

发明人： Matthew A. Bernstein

IPC分类号： G01V300

CPC分类号： G01R33/3614 ,  G01R33/288 ,  G01R33/583

摘要： An MRI system performs a pulse sequence to acquire image data from a subject. The RF power applied to the subject is monitored and the acquisition is altered if any one of three trip levels is exceeded. Each trip level is different and is associated with a different time interval over which applied RF power is measured.

摘要翻译： MRI系统执行脉冲序列以从对象获取图像数据。 如果超过三个行程级别中的任何一个，则监控施加到被摄体的RF功率，并且更改采集。 每个跳闸电平不同，并且与测量施加的RF功率的不同时间间隔相关联。

公开(公告)号：US06339626B1

公开(公告)日：2002-01-15

申请号：US09039436

申请日：1998-03-16

申请人： Matthew A. Bernstein ,  Jason A. Polzin ,  Bo J. Petersson ,  Frederick J. Frigo

发明人： Matthew A. Bernstein ,  Jason A. Polzin ,  Bo J. Petersson ,  Frederick J. Frigo

IPC分类号： H04L700

CPC分类号： G01R33/56

摘要： An MRI system acquires NMR signals and digitizes them at a fixed sample rate. A lower, prescribed sample rate is obtained by fractionally decimating the sampled NMR signals. Fractional decimation is achieved by a combination of zeropadding the sampled NMR signal in the frequency domain and decimating the sampled NMR signal in the time domain.

摘要翻译： MRI系统获取NMR信号并以固定的采样率数字化。 通过对采样的NMR信号进行分数抽取，获得较低的规定采样率。 通过在频域中加样采样的NMR信号并在时域中抽取采样的NMR信号来组合分数抽取。

公开(公告)号：US06249694B1

公开(公告)日：2001-06-19

申请号：US09118411

申请日：1998-07-17

申请人： Thomas K. F. Foo ,  Vincent B. Ho ,  Matthew A. Bernstein

发明人： Thomas K. F. Foo ,  Vincent B. Ho ,  Matthew A. Bernstein

IPC分类号： A61B5055

CPC分类号： G01R33/5635 ,  G01R33/5601 ,  G01R33/56572

摘要： A method of peripheral MR angiography is provided for imaging an artery or other vessel, wherein the vessel is of such length that MR data must be acquired at each of a plurality of scan stations spaced along the vessel. In accordance with the method, a contrast agent is intravenously injected, in order to provide a bolus which successively flows to each of the scan stations. After acquiring an initial subset of the MR data associated with a given scan station, the bolus is tracked to determine whether it has arrived at the next-following scan station. If so, at least some of the MR data associated with the next scan station are then acquired. However, if it is found that the bolus has not yet arrived at the next scan station, acquisition of further data at the given scan station is continued.

摘要翻译： 提供了一种用于对动脉或其他血管进行成像的外周MR血管造影术的方法，其中所述血管具有这样的长度，使得必须在沿着血管间隔开的多个扫描站中的每一个处获取MR数据。 根据该方法，静脉内注射造影剂，以提供连续流向每个扫描站的推注。 在获取与给定扫描站相关联的MR数据的初始子集之后，跟踪该推注以确定其是否到达下一个扫描站。 如果是，则随后获取与下一个扫描站相关联的至少一些MR数据。 然而，如果发现大剂量尚未到达下一个扫描站，则继续在给定扫描站获取进一步的数据。