公开(公告)号：US20080009701A1

公开(公告)日：2008-01-10

申请号：US11420224

申请日：2006-05-25

申请人： Hector E. Avram ,  James D. Hale ,  Ilya Simovsky ,  David M. Kramer

发明人： Hector E. Avram ,  James D. Hale ,  Ilya Simovsky ,  David M. Kramer

IPC分类号： A61B5/05

CPC分类号： G01R33/56341 ,  G01R33/5608 ,  G01R33/5615 ,  G01R33/5617 ,  G01R33/565 ,  G01R33/56509

摘要： In preferred embodiments, a fast spin echo imaging technique is provided that is insensitive to violations of the Carr Purcell Meiboom Gill (CPMG) condition. Diffusion gradients disrupt the CPMG condition, and, hence, the present fast spin echo method is compatible with diffusion measurements and diffusion weighted imaging. The preferred embodiments of the present technique involve splitting of spin echoes into echo pairs. Spin echoes are split by adjustment (in magnitude or duration) of an initial readout gradient pulse. A train of echo pairs is captured. A first image is constructed using the first echoes of each pair. Also, a second image is constructed using the second echoes of each pair. Hybrid radial Cartesian methods are used for constructing the first and second images. The first and second images are constructed independently of one another. Independent image construction renders the method insensitive to violation of the CPMG condition. Finally, the two images are combined to form a final image.

摘要翻译： 在优选实施例中，提供了对违反Carr Purcell Meiboom Gill（CPMG）条件不敏感的快速自旋回波成像技术。 扩散梯度破坏CPMG条件，因此，本发明的快速自旋回波方法与扩散测量和扩散加权成像兼容。 本技术的优选实施例涉及将自旋回波分解为回波对。 旋转回波通过初始读数梯度脉冲的调整（幅度或持续时间）分割。 一串回波对被捕获。 使用每对的第一个回波构建第一个图像。 此外，使用每对的第二回波来构建第二图像。 混合径向笛卡尔方法用于构建第一和第二图像。 第一和第二图像彼此独立构建。 独立的图像构造使得方法对违反CPMG条件不敏感。 最后，将两张图像合并形成最终图像。

公开(公告)号：US5235279A

公开(公告)日：1993-08-10

申请号：US837317

申请日：1992-02-19

申请人： Leon Kaufman ,  Joseph W. Carlson ,  Hector E. Avram

发明人： Leon Kaufman ,  Joseph W. Carlson ,  Hector E. Avram

IPC分类号： A61B5/055 ,  G01R33/34 ,  G01R33/381 ,  G01R33/385 ,  G01R33/389

CPC分类号： G01R33/385

摘要： An auxiliary insert MRI gradient coil is used to produce intense auxiliary magnetic gradient pulses during MRI sequences to improve MRI system performance. Although the auxiliary gradient coil may be of considerably reduced dimensions, thus, having considerably reduced uniformity, linearity and/or reproducibility than standard MRI gradient coils, coordinated use of both the regular MRI gradient coils and the auxiliary gradient coil can produce considerably enhanced MRI system performance in certain applications. Such auxiliary magnetic gradient coil may be used, for example, to provide spoiler pulses between MRI spin echo subsequences, as diffusion gradient pulses in diffusion MRI studies or as the oscillating gradient used to form successive gradient echoes in echo planar imaging.

摘要翻译： 辅助插入MRI梯度线圈用于在MRI序列期间产生强烈的辅助磁梯度脉冲，以改善MRI系统性能。 虽然辅助梯度线圈可能具有相当大的减小的尺寸，因此，与标准MRI梯度线圈相比，具有显着降低的均匀性，线性和/或再现性，协调使用常规MRI梯度线圈和辅助梯度线圈可以产生显着增强的MRI系统 在某些应用中的性能。 例如，这种辅助磁梯度线圈可以用于在MRI自旋回波子序列之间提供扰流脉冲，作为扩散MRI研究中的扩散梯度脉冲或用作在回波平面成像中形成连续梯度回波的振荡梯度。

公开(公告)号：US07538548B2

公开(公告)日：2009-05-26

申请号：US11420224

申请日：2006-05-25

申请人： Hector E. Avram ,  James D. Hale ,  Ilya Simovsky ,  David M. Kramer

发明人： Hector E. Avram ,  James D. Hale ,  Ilya Simovsky ,  David M. Kramer

IPC分类号： G01V3/00

CPC分类号： G01R33/56341 ,  G01R33/5608 ,  G01R33/5615 ,  G01R33/5617 ,  G01R33/565 ,  G01R33/56509

摘要： In preferred embodiments, a fast spin echo imaging technique is provided that is insensitive to violations of the Carr Purcell Meiboom Gill (CPMG) condition. Diffusion gradients disrupt the CPMG condition, and, hence, the present fast spin echo method is compatible with diffusion measurements and diffusion weighted imaging. The preferred embodiments of the present technique involve splitting of spin echoes into echo pairs. Spin echoes are split by adjustment (in magnitude or duration) of an initial readout gradient pulse. A train of echo pairs is captured. A first image is constructed using the first echoes of each pair. Also, a second image is constructed using the second echoes of each pair. Hybrid radial Cartesian methods are used for constructing the first and second images. The first and second images are constructed independently of one another. Independent image construction renders the method insensitive to violation of the CPMG condition. Finally, the two images are combined to form a final image.

摘要翻译： 在优选实施例中，提供了对违反Carr Purcell Meiboom Gill（CPMG）条件不敏感的快速自旋回波成像技术。 扩散梯度破坏CPMG条件，因此，本发明的快速自旋回波方法与扩散测量和扩散加权成像兼容。 本技术的优选实施例涉及将自旋回波分解为回波对。 旋转回波通过初始读数梯度脉冲的调整（幅度或持续时间）分割。 一串回波对被捕获。 使用每对的第一个回波构建第一个图像。 此外，使用每对的第二回波来构建第二图像。 混合径向笛卡尔方法用于构建第一和第二图像。 第一和第二图像彼此独立构建。 独立的图像构造使得方法对违反CPMG条件不敏感。 最后，将两张图像合并形成最终图像。

公开(公告)号：US6025714A

公开(公告)日：2000-02-15

申请号：US847813

申请日：1997-04-25

申请人： Hector E. Avram ,  Robert Wagner ,  Leon Kaufman ,  Andrew Li

发明人： Hector E. Avram ,  Robert Wagner ,  Leon Kaufman ,  Andrew Li

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

CPC分类号： G01R33/5615

摘要： A magnetic resonance imaging sequence synergistically combines Half Fourier Transform complex conjugation with shared echo imaging. The Half Fourier Transform complex conjugation reduces data acquisition time and permits the data acquisition per scan to be accomplished with a single RF transmission loop. The shared echo imaging provides multiple images of an image plane from a single scan, yet with different contrast and a larger number of slices. In an alternative embodiment, phase correction is provided between the non-shared echo responses.

摘要翻译： 磁共振成像序列协同地将半傅里叶变换复共轭与共享回波成像相结合。 半傅立叶变换复共轭减少数据采集时间，并允许每次扫描的数据采集通过单个RF传输环路完成。 共享回波成像从单次扫描提供图像平面的多个图像，但具有不同的对比度和更大数量的切片。 在替代实施例中，在非共享回波响应之间提供相位校正。