Le Bihan D, Mangin J F, Poupon C, Clark C A, Pappata S, Molko N, Chabriat H
Service Hospitalier Frédéric Joliot, CEA, 91406 Orsay, France.
J Magn Reson Imaging. 2001 Apr;13(4):534-46. doi: 10.1002/jmri.1076.
The success of diffusion magnetic resonance imaging (MRI) is deeply rooted in the powerful concept that during their random, diffusion-driven displacements molecules probe tissue structure at a microscopic scale well beyond the usual image resolution. As diffusion is truly a three-dimensional process, molecular mobility in tissues may be anisotropic, as in brain white matter. With diffusion tensor imaging (DTI), diffusion anisotropy effects can be fully extracted, characterized, and exploited, providing even more exquisite details on tissue microstructure. The most advanced application is certainly that of fiber tracking in the brain, which, in combination with functional MRI, might open a window on the important issue of connectivity. DTI has also been used to demonstrate subtle abnormalities in a variety of diseases (including stroke, multiple sclerosis, dyslexia, and schizophrenia) and is currently becoming part of many routine clinical protocols. The aim of this article is to review the concepts behind DTI and to present potential applications.
扩散磁共振成像（MRI）的成功深深植根于一个强大的概念，即在分子随机的、由扩散驱动的位移过程中，它们能在远超常规图像分辨率的微观尺度上探测组织结构。由于扩散实际上是一个三维过程，组织中的分子移动性可能是各向异性的，如在脑白质中。通过扩散张量成像（DTI），可以充分提取、表征和利用扩散各向异性效应，从而提供关于组织微观结构更精细的细节。最先进的应用无疑是脑部纤维追踪，它与功能MRI相结合，可能为连通性这一重要问题打开一扇窗口。DTI还被用于证明多种疾病（包括中风、多发性硬化症、诵读困难和精神分裂症）中的细微异常，目前正成为许多常规临床方案的一部分。本文的目的是回顾DTI背后的概念并介绍其潜在应用。
