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    Multi-slice and multi-angle MRI using fast spin echo acquisition
    3.
    发明授权
    Multi-slice and multi-angle MRI using fast spin echo acquisition 失效
    多切片和多角度MRI采用快速自旋回波采集

    公开(公告)号：US6134464A

    公开(公告)日：2000-10-17

    申请号：US12509

    申请日：1998-01-23

    申请人： Gousheng Tan ,  Matthew A. Bernstein ,  Steven M. Metcalfe

    发明人： Gousheng Tan ,  Matthew A. Bernstein ,  Steven M. Metcalfe

    IPC分类号： G01R33/48 ,  A61B5/055 ,  G01R33/54

    CPC分类号： G01R33/4833 ,  G01R33/4835

    摘要： A fast spin echo (FSE) pulse sequence is employed to perform a multi-slice, multi-angle MRI scan. The slices are scanned in groups, with all the slices in each group being oriented at the same angle and sampled in an interleaved manner. Total scan time is reduced by acquiring multiple, separately phase encoded echo signals during each FSE pulse sequence. Presaturation bands may be produced for each group of slices to reduce flow artifacts in the reconstructed slice images.

    摘要翻译： 采用快速自旋回波（FSE）脉冲序列进行多层多角度MRI扫描。 切片按组扫描，每组中的所有切片以相同的角度取向并以交错方式进行采样。 通过在每个FSE脉冲序列期间获取多个单独相位编码的回波信号来减少总扫描时间。 可以为每组切片产生预饱和带，以减少重建切片图像中的流动伪影。

    Method for acquiring spatially and spectrally selective MR images
    4.
    发明授权
    Method for acquiring spatially and spectrally selective MR images 失效
    用于获取空间和频谱选择性MR图像的方法

    公开(公告)号：US06175236B1

    公开(公告)日：2001-01-16

    申请号：US09047822

    申请日：1998-03-25

    申请人： Xiaohong Zhou ,  Matthew A. Bernstein

    发明人： Xiaohong Zhou ,  Matthew A. Bernstein

    IPC分类号： G01V300

    CPC分类号： G01R33/446 ,  G01R33/5613

    摘要： A method for acquiring spatially and spectrally selective MR images by means of an MR imaging system includes the step of selecting an SPSP pulse sequence, comprising a succession of RF sub-pulses and an oscillatory gradient magnetic field, which is disposed to select a slice through a subject. The method further includes measuring specified parameters of a perturbation magnetic field associated with the imaging system, and deriving an expression for the perturbation field from respective measured parameters and from the oscillatory gradient magnetic field. A specified ideal frequency modulation function, associated with the SPSP sequence, is disposed to offset the slice to a particular spatially localized region of the subject. The SPSP pulse sequence is modified by adjusting the frequency modulation function in specified corresponding relationship with the expression. The modified SPSP pulse sequence is then applied to the subject to excite a selected spectral species in the spatially localized region, while substantially reducing signal intensity loss resulting from the perturbation magnetic field.

    摘要翻译： 用于通过MR成像系统获取空间和频谱选择性MR图像的方法包括选择包括一系列RF子脉冲和振荡梯度磁场的SPSP脉冲序列的步骤，其被设置为选择切片通过 课程。 该方法还包括测量与成像系统相关联的扰动磁场的指定参数，以及从相应的测量参数和振荡梯度磁场导出扰动场的表达式。 设置与SPSP序列相关联的指定的理想频率调制功能，以将切片偏移到对象的特定空间局部区域。 通过调整与规定的对应关系的频率调制函数来修改SPSP脉冲序列。 然后将经修改的SPSP脉冲序列应用于受试者以激发空间局部区域中的选定光谱物种，同时显着降低由扰动磁场引起的信号强度损失。

    Correction of artifacts caused by maxwell terms in slice offset echo planar imaging
    6.
    发明授权
    Correction of artifacts caused by maxwell terms in slice offset echo planar imaging 有权
    校正由切片偏移回波平面成像中的maxwell项引起的假象

    公开(公告)号：US06064205A

    公开(公告)日：2000-05-16

    申请号：US265259

    申请日：1999-03-09

    申请人： Xiaohong Zhou ,  Yiping Du ,  Matthew A. Bernstein ,  Hammond G. Reynolds ,  Joseph K. Maier ,  Jason A. Polzin

    发明人： Xiaohong Zhou ,  Yiping Du ,  Matthew A. Bernstein ,  Hammond G. Reynolds ,  Joseph K. Maier ,  Jason A. Polzin

    IPC分类号： G01R33/32 ,  A61B5/055 ,  G01R33/54 ,  G01R33/561 ,  G01R33/565 ,  G01V3/00

    CPC分类号： G01R33/56581 ,  G01R33/56554

    摘要： Two methods are disclosed to remove the image artifacts produced by Maxwell terms arising from the imaging gradients in an echo planar imaging pulse sequence. In the first method, the frequency and phase errors caused by the Maxwell terms are calculated on an individual slice basis and subsequently compensated during data acquisition by dynamically adjusting the receiver frequency and phase. In the second method, two linear phase errors, one in the readout direction and the other in the phase-encoding direction, both of which arise from the Maxwell terms, are calculated on an individual-slice basis. These errors are compensated for in the k-space data after data acquisition.

    摘要翻译： 公开了两种方法来去除由回波平面成像脉冲序列中的成像梯度引起的由麦克斯韦尔产生的图像伪影。 在第一种方法中，由麦克斯韦尔项引起的频率和相位误差在单独的切片基础上计算，并随后通过动态调整接收机频率和相位在数据采集期间进行补偿。 在第二种方法中，以单个切片为基础计算两个线性相位误差，一个在读出方向上，另一个在相位编码方向上，两个来自麦克斯韦术语。 这些误差在数据采集后的k空间数据中得到补偿。

    Method of performing magnetic resonance angiography using two-dimensional imaging and de-rated gradients
    10.
    发明授权
    Method of performing magnetic resonance angiography using two-dimensional imaging and de-rated gradients 有权
    使用二维成像和降额梯度进行磁共振血管造影的方法

    公开(公告)号：US06259940B1

    公开(公告)日：2001-07-10

    申请号：US09301246

    申请日：1999-04-28

    申请人： Matthew A. Bernstein ,  John Huston, III

    发明人： Matthew A. Bernstein ,  John Huston, III

    IPC分类号： A61B5055

    CPC分类号： G01R33/5635 ,  G01R33/56308 ,  G01R33/56518 ,  G01R33/56581

    摘要： In an MRI system using high-performance gradient hardware, a method includes de-rating selected lobes in a 2DTOF imaging pulse sequence; employing images from the two-dimensional imagery to detect the presence of disease; and performing three-dimensional contrast-enhanced MRA if disease was detected at a sufficiently high level to make three-dimensional imaging useful. By de-rating selected lobes of the 2DTOF imaging pulse sequence, sensitivity to carotid stenosis at or above the clinically important range of 60-70% is achieved.

    摘要翻译： 在使用高性能梯度硬件的MRI系统中，一种方法包括以2DTOF成像脉冲序列降低所选择的瓣; 使用二维图像的图像来检测疾病的存在; 并且如果在足够高的水平检测到疾病以使三维成像有用，则执行三维造影增强MRA。 通过降低2DTOF成像脉冲序列的选定的瓣膜，实现了临床上重要范围为60-70％之间的颈动脉狭窄的敏感性。