Huisman Thierry A G M
Department of Radiology, Neuroradiology Section and MGH-NMR Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02129, USA.
Eur Radiol. 2003 Oct;13(10):2283-97. doi: 10.1007/s00330-003-1843-6. Epub 2003 Mar 6.
Diffusion-weighted imaging (DWI) of the brain represents a new imaging technique that extends imaging from depiction of neuroanatomy to the level of function and physiology. DWI measures a fundamentally different physiological parameter compared with conventional MRI. Image contrast is related to differences in the diffusion rate of water molecules rather than to changes in total tissue water. DWI can reveal pathology in cases where conventional MRI remains unremarkable. DWI has proven to be highly sensitive in the early detection of acute cerebral ischemia and seems promising in the evaluation of traumatic brain injury. DWI can differentiate between lesions with decreased and increased diffusion. In addition, full-tensor DWI can evaluate the microscopic architecture of the brain, in particular white matter tracts, by measuring the degree and spatial distribution of anisotropic diffusion within the brain. This article reviews the basic concepts of DWI and its application in cerebral ischemia and traumatic brain injury.
脑部扩散加权成像（DWI）是一种新的成像技术，它将成像从神经解剖结构的描绘扩展到功能和生理水平。与传统MRI相比，DWI测量的是一个根本不同的生理参数。图像对比度与水分子扩散速率的差异有关，而不是与总组织水的变化有关。在传统MRI无明显异常的情况下，DWI可以揭示病变。事实证明，DWI在急性脑缺血的早期检测中具有高度敏感性，并且在创伤性脑损伤的评估中似乎很有前景。DWI可以区分扩散减少和增加的病变。此外，全张量DWI可以通过测量脑内各向异性扩散的程度和空间分布来评估脑的微观结构，特别是白质束。本文综述了DWI的基本概念及其在脑缺血和创伤性脑损伤中的应用。
