Anderson A W, Gore J C
Department of Diagnostic Radiology, Yale School of Medicine, New Haven, Connecticut 06510.
Magn Reson Med. 1994 Sep;32(3):379-87. doi: 10.1002/mrm.1910320313.
For diffusion-weighted magnetic resonance imaging and under circumstances where patient movement can be modeled as rigid body motion, it is shown both theoretically and experimentally that translations and rotations produce phase errors which are zero- and first-order, respectively, in position. While a navigator echo can be used to correct the imaging data for arbitrary translations, only when the diffusion gradient is applied in the phase encode direction is there sufficient information to correct for rotations around all axes, and therefore for general rigid body motion. Experiments in test objects and human brain imaging confirm theoretical predictions and demonstrate that appropriate corrections dramatically improve image quality in vivo.
对于扩散加权磁共振成像，以及在患者运动可建模为刚体运动的情况下，理论和实验均表明，平移和旋转分别会产生位置上零阶和一阶的相位误差。虽然导航回波可用于校正任意平移的成像数据，但只有当扩散梯度沿相位编码方向施加时，才会有足够信息校正围绕所有轴的旋转，从而校正一般的刚体运动。在测试物体和人脑成像中的实验证实了理论预测，并表明适当的校正可显著提高体内图像质量。
