Mukherjee P, Berman J I, Chung S W, Hess C P, Henry R G
Department of Radiology, University of California, San Francisco, San Francisco, CA 94143-0628, USA.
AJNR Am J Neuroradiol. 2008 Apr;29(4):632-41. doi: 10.3174/ajnr.A1051. Epub 2008 Mar 13.
In this article, the underlying theory of clinical diffusion MR imaging, including diffusion tensor imaging (DTI) and fiber tractography, is reviewed. First, a brief explanation of the basic physics of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping is provided. This is followed by an overview of the additional information that can be derived from the diffusion tensor, including diffusion anisotropy, color-encoded fiber orientation maps, and 3D fiber tractography. This article provides the requisite background for the second article in this 2-part review to appear next month, which covers the major technical factors that affect image quality in diffusion MR imaging, including the acquisition sequence, magnet field strength, gradient amplitude and slew rate, and multichannel radio-frequency coils and parallel imaging. The emphasis is on optimizing these factors for state-of-the-art DWI and DTI based on the best available evidence in the literature.
本文回顾了临床扩散磁共振成像的基础理论，包括扩散张量成像（DTI）和纤维束成像。首先，简要解释了扩散加权成像（DWI）和表观扩散系数（ADC）图的基本物理原理。接着概述了可从扩散张量得出的其他信息，包括扩散各向异性、颜色编码的纤维取向图和三维纤维束成像。本文为下个月发表的这篇分两部分的综述的第二篇文章提供了必要的背景知识，第二篇文章将涵盖影响扩散磁共振成像图像质量的主要技术因素，包括采集序列、磁场强度、梯度幅度和 slew 率，以及多通道射频线圈和平行成像。重点是根据文献中现有的最佳证据，针对最先进的 DWI 和 DTI 优化这些因素。
