Helpern J A, Huang N
Division of Medical PHysics, Nathan Kline Institute, Orangeburg, NY 10962, USA.
Magn Reson Imaging. 1995;13(8):1227-31. doi: 10.1016/0730-725x(95)02036-s.
Diffusion-weighted imaging (DWI) is a relatively new magnetic resonance imaging (MRI) technique that can be used to probe the microenvironment of water. Contrast in DWI depends on properties different from traditional T1 and T2 contrast, and is derived form the translational motion of water molecules. Since it is reasonable to think that a change in the microenvironment of water might be reflected in a change in water diffusion characteristics, the quantitative assessment of the (apparent) diffusion coefficient ADCw may represent a unique means of assessing tissue status. DWI has already shown great utility in the study of cerebral ischemia in animal models and has proved useful in the early identification of cerebral ischemia in patients. More recent reports have indicated a potential for DWI in studying epilepsy. Here, we briefly review some of what is known about the measurement of ADCw in ischemia and compare these results with what has recently been reported for epilepsy. In this manner we hope to better understand the underlying mechanisms behind changes in water diffusion associated with specific pathologies.
扩散加权成像（DWI）是一种相对较新的磁共振成像（MRI）技术，可用于探测水的微环境。DWI中的对比度取决于与传统T1和T2对比度不同的特性，并且源自水分子的平移运动。由于认为水微环境的变化可能反映在水扩散特征的变化中是合理的，因此（表观）扩散系数ADCw的定量评估可能代表一种评估组织状态的独特方法。DWI已在动物模型的脑缺血研究中显示出巨大的实用性，并已被证明在早期识别患者脑缺血方面有用。最近的报告表明DWI在研究癫痫方面具有潜力。在这里，我们简要回顾一下关于缺血中ADCw测量的已知情况，并将这些结果与最近关于癫痫的报告进行比较。通过这种方式，我们希望更好地理解与特定病理相关的水扩散变化背后的潜在机制。
