Moseley M E, Kucharczyk J, Asgari H S, Norman D
Department of Radiology, University of California, San Francisco 94143.
Magn Reson Med. 1991 Jun;19(2):321-6. doi: 10.1002/mrm.1910190222.
Diffusional anisotropy of water protons, induced by nonrandom, directional barriers which hinder or retard water motion, is measurable by MRI. Faster water diffusion was observed when the diffusion-sensitizing gradient direction paralleled the long axes of white matter tracts, indicative of fewer barriers to water motion. Diffusion perpendicular to this axis was as much as four times slower. Anisotropy was seen pre- and postmortem in all axial, sagittal, and coronal planes, with and without cardiac gating. Ordering has also been observed in feline optic nerve and in human peripheral nerves. Utilization of this technique can greatly improve understanding and assessment of demyelinating disorders, of white matter infarcts and neoplasms, and of neonatal brain and spinal cord development.
由阻碍或减缓水分子运动的非随机定向屏障所诱导的水质子扩散各向异性，可通过磁共振成像（MRI）进行测量。当扩散敏感梯度方向与白质束的长轴平行时，观察到更快的水扩散，这表明水分子运动的屏障较少。垂直于该轴的扩散速度慢至四倍。在所有轴向、矢状面和冠状面，无论有无心脏门控，生前和死后均观察到各向异性。在猫的视神经和人类周围神经中也观察到了有序性。利用该技术可极大地增进对脱髓鞘疾病、白质梗死和肿瘤以及新生儿脑和脊髓发育的理解与评估。
