公开(公告)号：US6008647A

公开(公告)日：1999-12-28

申请号：US831684

申请日：1997-04-10

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

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

IPC分类号： G01R33/48 ,  A61B5/055 ,  G01R33/561 ,  G01R33/565 ,  G01V3/00

CPC分类号： G01R33/56581 ,  G01R33/56554

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.

公开(公告)号：US5998996A

公开(公告)日：1999-12-07

申请号：US826183

申请日：1997-03-27

申请人： Matthew A. Bernstein ,  Xiaohang Zhou ,  Kevin F. King ,  Alexander Ganin ,  Gary H. Glover ,  Norbert J. Pelc ,  Jason A. Polzin

发明人： Matthew A. Bernstein ,  Xiaohang Zhou ,  Kevin F. King ,  Alexander Ganin ,  Gary H. Glover ,  Norbert J. Pelc ,  Jason A. Polzin

IPC分类号： G01R33/54 ,  A61B5/055 ,  G01R33/563 ,  G01R33/565 ,  G01V3/00

CPC分类号： G01R33/56581 ,  G01R33/56308

摘要： A method is presented for correcting Maxwell term error artifacts produced by an NMR system during the production of either a phase contrast angiogram or a complex difference angiogram. Phase corrections are made to the reconstructed phase image to eliminate the artifacts. Correction coefficients calculated from the flow encoding magnetic gradient waveforms of the phase contrast pulse sequence are used in a polynomial to calculate a set of phase error corrections. These corrections are then used to adjust the phase at each pixel of the angiogram image.

摘要翻译： 提出了一种用于在生产相位对比血管造影或复杂差异血管造影图中校正由NMR系统产生的麦克斯韦尔术语误差伪像的方法。 对重建的相位图像进行相位校正，以消除伪影。 由相位对比脉冲序列的流量编码磁梯度波形计算的校正系数用于多项式以计算一组相位误差校正。 然后使用这些校正来调整血管造影图像的每个像素处的相位。

公开(公告)号：US5877629A

公开(公告)日：1999-03-02

申请号：US831546

申请日：1997-04-08

申请人： Kevin F. King ,  Alexander Ganin ,  Xiaohang Zhou ,  Matthew A. Bernstein

发明人： Kevin F. King ,  Alexander Ganin ,  Xiaohang Zhou ,  Matthew A. Bernstein

IPC分类号： G01R33/561 ,  G01R33/565 ,  G01R33/20

CPC分类号： G01R33/56554 ,  G01R33/4824 ,  G01R33/56581

摘要： Artifacts in NMR images produced by Maxwell terms during non-rectilinear scans, such as spiral scans, are reduced or eliminated. Phase corrections for in-plane and through-plane blurring are used to offset Maxwell terms errors.

摘要翻译： 减少或消除在非直线扫描（如螺旋扫描）期间由麦克斯韦尔术语产生的NMR图像中的伪像。 用于平面和平面模糊的相位校正用于抵消麦克斯韦尔术语误差。