公开(公告)号：US5017872A

公开(公告)日：1991-05-21

申请号：US467475

申请日：1990-01-19

申请人： Thomas K. Foo ,  Cecil E. Hayes ,  Yoon-Won Kang

发明人： Thomas K. Foo ,  Cecil E. Hayes ,  Yoon-Won Kang

IPC分类号： A61B5/055 ,  G01R33/34 ,  G01R33/422

CPC分类号： G01R33/34076 ,  G01R33/422 ,  G01R33/5659

摘要： An RF coil assembly for an NMR instrument includes a cylindrical coil surrounded by a cylindrical shield. The annular space between the coil and the shield is filled with a dielectric material having a relative permittivity selected to improve the RF field homogeneity in the radial direction.

摘要翻译： 用于NMR仪器的RF线圈组件包括由圆柱形屏蔽件围绕的圆柱形线圈。 线圈和屏蔽之间的环形空间填充有选择的相对介电常数的介电材料，以改善径向方向的RF场均匀性。

公开(公告)号：US5053711A

公开(公告)日：1991-10-01

申请号：US467474

申请日：1990-01-19

申请人： Cecil E. Hayes ,  Thomas K. Foo

发明人： Cecil E. Hayes ,  Thomas K. Foo

IPC分类号： A61B5/055 ,  G01R33/34 ,  G01R33/422

CPC分类号： G01R33/3453 ,  G01R33/34046 ,  G01R33/422

摘要： An RF coil assembly for an NMR instrument includes a cylindrical shield which encloses a set of equally spaced linear conductors that surround a central axis. A set of shielded conductors connect to the ends of the linear conductors to form loops. The effective lengths of the loops and the RF signal source which drives the loops are selected to improve the homogeneity of the RF field produced along the central axis.

摘要翻译： 用于NMR仪器的RF线圈组件包括圆柱形屏蔽件，其包围围绕中心轴线的一组等距间隔的线性导体。 一组屏蔽导体连接到线性导体的端部以形成环路。 选择驱动环路的环路和RF信号源的有效长度以改善沿着中心轴产生的RF场的均匀性。

公开(公告)号：US5545992A

公开(公告)日：1996-08-13

申请号：US510683

申请日：1995-08-03

申请人： Thomas K. Foo

发明人： Thomas K. Foo

IPC分类号： G01R33/48 ,  A61B5/055 ,  G01R33/561 ,  G01R33/567 ,  G01V3/00

CPC分类号： G01R33/5613 ,  G01R33/5616 ,  G01R33/5673

摘要： A fast gradient echo, cardiac gated NMR scan is performed by acquiring groups of views during each cardiac cycle. Each group of views is preceded by an accelerator RF pulse and disdaq pulse sequences to improve T.sub.1 contrast and drive spin magnetization rapidly to dynamic equilibrium.

摘要翻译： 通过在每个心动周期期间获取观察组来执行快速梯度回波，心脏门控NMR扫描。 每组视图之前都有加速器RF脉冲和反相脉冲序列，以改善T1对比度并快速驱动自旋磁化到动态平衡。

公开(公告)号：US5168227A

公开(公告)日：1992-12-01

申请号：US693895

申请日：1991-05-01

申请人： Thomas K. Foo ,  Beth E. Slayman

发明人： Thomas K. Foo ,  Beth E. Slayman

IPC分类号： A61B5/055 ,  G01R33/48 ,  G01R33/56

CPC分类号： G01R33/56

摘要： An NMR system acquires a series of spin-echo signals during a scan and these are used to reconstruct an image. The spin-echo signals are partially acquired by locating the data acquisition window asymmetrically with respect to the echo peak. A homodyne reconstruction is employed to fill in the missing data during the image reconstruction.

公开(公告)号：US05997883A

公开(公告)日：1999-12-07

申请号：US886487

申请日：1997-07-01

申请人： Frederick H. Epstein ,  Andrew E. Arai ,  Jeffrey A. Feinstein ,  Thomas K. Foo ,  Steven D. Wolff

发明人： Frederick H. Epstein ,  Andrew E. Arai ,  Jeffrey A. Feinstein ,  Thomas K. Foo ,  Steven D. Wolff

IPC分类号： A61B5/0456 ,  G01R33/567 ,  G01V3/00

CPC分类号： A61B5/7292 ,  G01R33/5673 ,  A61B5/0456 ,  A61B5/7289

摘要： A method is disclosed to reconstruct multiphase MR images that accurately depict the entire cardiac cycle. A segmented, gradient-recalled-echo sequence is modified to acquire data continuously. Images are retrospectively reconstructed by selecting views from each heartbeat based on cardiac phase rather than the time elapsed from the QRS complex. Cardiac phase is calculated using a model that compensates for beat-to-beat heart rate changes.

摘要翻译： 公开了一种重建准确描绘整个心动周期的多相MR图像的方法。 修改分段渐变回波序列以连续采集数据。 通过基于心脏相位而不是从QRS复合体经过的时间选择来自每个心跳的视图来回顾性地重建图像。 使用补偿搏动心跳变化的模型计算心脏相。

公开(公告)号：US5256967A

公开(公告)日：1993-10-26

申请号：US955097

申请日：1992-10-01

申请人： Thomas K. Foo ,  Patrick L. Le Roux

发明人： Thomas K. Foo ,  Patrick L. Le Roux

IPC分类号： G01R33/54 ,  G01R33/561 ,  G01K3/00

CPC分类号： G01R33/4828 ,  G01R33/561

摘要： An NMR system performs a 2DFT or 3DFT scan using a set of steady-state free precession (SSFP) pulse sequences. A contrast preparation pulse sequence precedes each series of SSFP pulse sequences and it includes a spectrally selective RF inversion pulse timed to water to provide T.sub.1 contrast between tissues having relatively long T.sub.1 times, followed by a spectrally selective RF inversion pulse tuned to suppress the signals from fat.

摘要翻译： NMR系统使用一组稳态自由进动（SSFP）脉冲序列执行2DFT或3DFT扫描。 对比准备脉冲序列在每个SSFP脉冲序列之前，并且包括定时到水的频谱选择性RF反转脉冲，以在具有相对较长的T1时间的组织之间提供T1对比，随后调整频谱选择性RF反转脉冲以抑制来自 脂肪。

公开(公告)号：US5377680A

公开(公告)日：1995-01-03

申请号：US102166

申请日：1993-08-04

申请人： Tsur Bernstein ,  Thomas K. Foo

发明人： Tsur Bernstein ,  Thomas K. Foo

IPC分类号： A61B5/055 ,  G01R33/567

CPC分类号： G01R33/5673 ,  A61B5/0555 ,  G01R33/4818

摘要： Fast NMR pulse sequences are employed to acquire data sets from which a set of images can be reconstructed depicting a patient's heart at successive phases during the cardiac cycle. The number of images is increased by selecting views from adjacent data sets to form interpolated data sets that are employed to reconstruct images depicting the patient's heart at cardiac phases between the successive phases.

摘要翻译： 使用快速NMR脉冲序列来获取数据集，从心脏周期中连续相位可以重建一组图像，描绘患者的心脏。 通过从相邻数据集中选择视图来增加图像的数量，以形成用于重建在连续相之间的心脏阶段描绘患者心脏的图像的内插数据集。

公开(公告)号：US5291891A

公开(公告)日：1994-03-08

申请号：US920351

申请日：1992-07-27

申请人： Thomas K. Foo ,  Matthew A. Bernstein

发明人： Thomas K. Foo ,  Matthew A. Bernstein

IPC分类号： G01R33/567 ,  A61B5/055

CPC分类号： G01R33/5676

摘要： T*.sub.2 contrast in images reconstructed from fast NMR pulse sequences is improved by increasing the gradient recalled echo time TE. The pulse repetition time TR is minimized to maintain high temporal resolution by asymmetrically acquiring the echo signal with its peak disposed bear the end of the acquisition window.

摘要翻译： 通过增加梯度回波回波时间TE来提高从快速NMR脉冲序列重建的图像中的T * 2对比度。 脉冲重复时间TR被最小化以通过不对称地获取回波信号来保持高的时间分辨率，其峰值设置承载采集窗口的末端。

公开(公告)号：US5604435A

公开(公告)日：1997-02-18

申请号：US581284

申请日：1995-12-29

申请人： Thomas K. Foo ,  Kevin F. King

发明人： Thomas K. Foo ,  Kevin F. King

IPC分类号： G01R33/48 ,  G01R33/50 ,  G01V3/00

CPC分类号： G01R33/50 ,  G01R33/446

摘要： A method is provided for rapidly measuring change in T.sub.2 * in a region of an MR imaging subject, the method employing a double gradient echo sequence with spiral readout. In this technique, two gradient echoes are acquired after a single RF excitation. A first readout trajectory spirals out from the center of k-space, i.e., k.sub.r =0, to some maximum radius, and then a second readout trajectory spirals back towards the center of k-space. A gradient echo is formed each time a k-space trajectory passes through the center of k-space. The signal intensity of the two echoes allows the calculation of the T.sub.2 * values on a pixel by pixel basis. The ability to measure changes in T.sub.2 * allows measurement of change in perfusion to be quantified.

摘要翻译： 提供了一种用于快速测量MR成像对象区域中T2 *的变化的方法，该方法采用具有螺旋读出的双梯度回波序列。 在这种技术中，在单个RF激发之后获得两个梯度回波。 第一个读出轨迹从k空间的中心，即kr = 0，螺旋向某一最大半径，然后第二个读出轨迹向k空间的中心旋转。 每当k空间轨迹穿过k空间的中心时形成梯度回波。 两个回波的信号强度允许逐个像素地计算T2 *值。 测量T2 *变化的能力允许测量灌注变化量化。

公开(公告)号：US5435303A

公开(公告)日：1995-07-25

申请号：US263573

申请日：1994-06-23

申请人： Matthew A. Bernstein ,  Thomas K. Foo

发明人： Matthew A. Bernstein ,  Thomas K. Foo

IPC分类号： A61B5/055 ,  G01R33/567

CPC分类号： A61B5/0555 ,  G01R33/4818 ,  G01R33/5673

摘要： Flow encoded NMR pulse sequences are employed to acquire data sets from which a set of angiographic images can be reconstructed depicting blood flow at successive phases during the cardiac cycle. The number of angiographic images is increased by selecting views from adjacent data sets to form interpolated data sets that are employed to reconstruct angiographic images depicting blood flow at cardiac phases between the successive phases.

摘要翻译： 采用流动编码的NMR脉冲序列来获取数据集，从该数据集可以重建一组血管造影图像，描绘在心动周期期间连续相位的血流量。 通过从相邻数据集中选择视图来增加血管造影图像的数量，以形成用于重建描绘连续相之间的心脏相位的血流的血管造影图像的内插数据集。