Macgowan C K, Wood M L
Department of Medical Biophysics, University of Toronto, Canada.
Magn Reson Med. 1996 Mar;35(3):391-8. doi: 10.1002/mrm.1910350318.
A new method for suppressing the effects of motion in MR images by reordering the acquisition of k space has been developed. Existing reordering methods suffer from image blurring. The method presented here applies specifically to translation along the phase-encoding direction, in which case it reduces both ghosting and blurring. The method is conceptually similar to a linear phase shift of k space, except that it has the advantage of not corrupting stationary structures inadvertently. The method is intended for anatomic sites in which substantial translational motion occurs along the phase-encoding direction, such as the cranial-caudal motion of the liver and kidneys. The reordering method is motivated from an analysis of factors affecting the severity of motion artifacts. The theory behind the reordering method is described and validated experimentally by imaging a moving phantom.
一种通过重新排序k空间采集来抑制磁共振图像中运动影响的新方法已经被开发出来。现有的重新排序方法存在图像模糊的问题。这里提出的方法特别适用于沿相位编码方向的平移，在这种情况下，它可以减少鬼影和模糊。该方法在概念上类似于k空间的线性相移，不同的是它具有不会无意中破坏静止结构的优点。该方法适用于沿相位编码方向发生大量平移运动的解剖部位，如肝脏和肾脏的头-尾运动。重新排序方法是基于对影响运动伪影严重程度的因素的分析而提出的。通过对移动体模成像，描述了重新排序方法背后的理论并进行了实验验证。
