Moseley M E, Cohen Y, Kucharczyk J, Mintorovitch J, Asgari H S, Wendland M F, Tsuruda J, Norman D
Department of Radiology, University of California, San Francisco 94143.
Radiology. 1990 Aug;176(2):439-45. doi: 10.1148/radiology.176.2.2367658.
The diffusion behavior of intracranial water in the cat brain and spine was examined with the use of diffusion-weighted magnetic resonance (MR) imaging, in which the direction of the diffusion-sensitizing gradient was varied between the x, y, and z axes of the magnet. At very high diffusion-sensitizing gradient strengths, no clear evidence of anisotropic water diffusion was found in either cortical or subcortical (basal ganglia) gray matter. Signal intensities clearly dependent on orientation were observed in the cortical and deep white matter of the brain and in the white matter of the spinal cord. Greater signal attenuation (faster diffusion) was observed when the relative orientation of white matter tracts to the diffusion-sensitizing gradient was parallel as compared to that obtained with a perpendicular alignment. These effects were seen on both premortem and immediate postmortem images obtained in all axial, sagittal, and coronal views. Potential applications of this MR imaging technique included the stereospecific evaluation of white matter in the brain and spinal cord and in the characterization of demyelinating and dysmyelinating diseases.
利用扩散加权磁共振（MR）成像检查了猫脑和脊髓中颅内水的扩散行为，其中扩散敏感梯度的方向在磁体的x、y和z轴之间变化。在非常高的扩散敏感梯度强度下，在皮质或皮质下（基底神经节）灰质中均未发现明显的各向异性水扩散证据。在大脑的皮质和深部白质以及脊髓的白质中观察到明显依赖于方向的信号强度。与垂直排列相比，当白质束与扩散敏感梯度的相对方向平行时，观察到更大的信号衰减（更快的扩散）。在所有轴向、矢状和冠状视图中获得的生前和死后即刻图像上均可见到这些效应。这种MR成像技术的潜在应用包括对脑和脊髓白质的立体定向评估以及脱髓鞘和髓鞘形成异常疾病的特征描述。
