Fu Z W, Wang Y, Grimm R C, Rossman P J, Felmlee J P, Riederer S J, Ehman R L
Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN 55905, USA.
Magn Reson Med. 1995 Nov;34(5):746-53. doi: 10.1002/mrm.1910340514.
A single "orbital" navigator echo, that has a circular k-space trajectory, is used to simultaneously measure in-plane rotational and multi-axis translational global motion. Rotation is determined from the shift in the magnitude profile of the echo with respect to a reference echo. Displacements are calculated from the phase difference between the current echo and a reference echo. Phantom studies show that this technique can accurately measure rotation and translations. Preliminary results from adaptive motion correction studies on phantom and human subjects indicate that the orbital navigator echo is an effective method for motion measurement in MRI.
一个具有圆形k空间轨迹的单一“轨道”导航回波用于同时测量平面内旋转和多轴平移全局运动。旋转是根据回波幅度轮廓相对于参考回波的偏移来确定的。位移是根据当前回波与参考回波之间的相位差计算得出的。模型研究表明，该技术可以准确测量旋转和平移。对模型和人体受试者进行的自适应运动校正研究的初步结果表明，轨道导航回波是MRI中运动测量的一种有效方法。
