公开(公告)号：US20030117136A1

公开(公告)日：2003-06-26

申请号：US10272431

申请日：2002-10-16

申请人： Cornell Research Foundation, Inc.

发明人： Yi Wang ,  Thanh D. Nguyen

IPC分类号： G01V003/00

CPC分类号： G01R33/5676

摘要： A method and apparatus for detecting displacement of an object using navigator echoes is presented. For motion that is linear in 3D, a linear regression on k-space data is performed by fitting a straight line to the motion-induced phase shift using a k-space weighted least squares minimization to find the displacement. For general motion due to rotation, dilation, and displacement, a rotation angle and dilation scaling factors are determined from the magnitude k-space data by a weighted least squares minimization. A displacement vector is then obtained from the phase data in k-space using a weighted least squares minimization. The weighting factor takes into account that the noise in k-space is inversely proportional to the signal to noise ration. For motion of coronary arteries, the k-space data is acquired in one embodiment using selective volumetric excitation and sampling the resulting excited signal with a trajectory sensitized to the motion of interest.

摘要翻译： 提出了一种利用导航回波检测物体位移的方法和装置。 对于在3D中是线性的运动，通过使用k空间加权最小二乘法最小化拟合直线到运动引起的相移来执行k空间数据的线性回归，以找到位移。 对于由于旋转，扩张和位移而导致的一般运动，通过加权最小二乘法最小化从幅度k空间数据确定旋转角度和扩张缩放因子。 然后使用加权最小二乘法最小化从k空间中的相位数据获得位移矢量。 加权因子考虑到k空间中的噪声与信噪比成反比。 对于冠状动脉的运动，在一个实施例中，使用选择性体积激励获取k空间数据，并且对所得到的激励信号采样以对感兴趣的运动敏感的轨迹进行采样。

公开(公告)号：US20030032877A1

公开(公告)日：2003-02-13

申请号：US10109888

申请日：2002-04-01

申请人： Cornell Research Foundation, Inc.

发明人： Richard Watts ,  Yi Wang ,  Martin R. Prince

IPC分类号： A61B005/05

CPC分类号： G01R33/5601 ,  A61B5/055

摘要： Current bolus chase magnetic resonance angiography is limited by the imaging time for each station. Tailoring the density of k-space sampling along the anterior-posterior direction of the coronal station allows a substantial decrease in scan time that leads to greater contrast bolus sharing among stations and consequently a significant improvement in image quality. Fast arterial-venous transit in the carotid arteries requires accurate, reliable timing of the acquisition to the bolus transit to maximize arterial signal and minimize venous artifacts. The rising edge of the bolus is not utilized in conventional elliptical-centric view ordering because the critical k-space center must be acquired with full arterial enhancement. The invention provides a recessed elliptical-centric view ordering scheme is introduced in which the k-space center is acquired a few seconds following scan initiation. The recessed view ordering is shown to be more robust to timing errors in a patient studies.

摘要翻译： 目前的推注磁共振血管造影受每个站的成像时间的限制。 沿着冠状站的前后方向调整k空间采样的密度允许扫描时间的显着减少，导致站之间更大的对比度推注共享，并且因此显着改善图像质量。 在颈动脉中的快速动脉 - 静脉转运需要准确，可靠的采集到推注转运的时间，以最大化动脉信号并使静脉伪影最小化。 在常规的以椭圆为中心的视图排序中，推注的上升边缘不被利用，因为必须以完全动脉增强获得临界k空间中心。 本发明提供了一种以椭圆为中心的视图排序方案，其中在扫描开始后几秒钟内获取k空间中心。 凹陷视图排序显示出对患者研究中的定时误差更为鲁棒。

公开(公告)号：US20020188191A1

公开(公告)日：2002-12-12

申请号：US10164502

申请日：2002-06-06

申请人： Cornell Research Foundation, Inc.

发明人： Vladimir N. Kolmogorov ,  Yi Wang ,  Ramin Zabih

IPC分类号： A61B005/055 ,  G06F017/00

CPC分类号： A61B5/7289 ,  A61B5/055 ,  G01R33/5608 ,  G01R33/5676

摘要： An efficient navigator method is presented that substantially increases the scan efficiency while maintaining the motion suppression effectiveness in magnetic resonance imaging. The method is achieved by simultaneously acquiring different image volumes at different motion states of the subject being scanned. A scheduling algorithm is used to assign volumes to position bins of a motion histogram of the subject. The motion histogram is periodically updated and the volumes are reassigned to position bins.

摘要翻译： 提出了一种有效的导航仪方法，其显着提高了扫描效率，同时保持了磁共振成像中的运动抑制效果。 该方法通过在被扫描的对象的不同运动状态下同时获取不同的图像体积来实现。 调度算法用于将卷分配给对象的运动直方图的位置仓。 周期性更新运动直方图，并将卷重新分配到位置仓。