Advanced Imaging Research Center and Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
Neuroscientist. 2010 Dec;16(6):634-49. doi: 10.1177/1073858409356711. Epub 2010 Apr 1.
Human brain anatomy is extraordinarily complex, and yet, its origin is a simple tubular structure. It is characterized by dramatic structural changes during fetal development. Revealing detailed anatomy at different stages of human fetal brain development not only aids in understanding this highly ordered process but also provides clues to detect abnormalities caused by genetic or environmental factors. However, anatomical studies of human brain development during this period are surprisingly scarce, and histology-based atlases have become available only recently. Diffusion tensor imaging (DTI), a recently developed technology of magnetic resonance imaging (MRI), is capable of noninvasively delineating macroscopic anatomical components with high contrast and revealing structures at the microscopic level. In this article, the fetal brain white matter is explored using contrasts from DTI-derived images and axonal reconstruction from DTI tractography. The highly organized structures in the cerebral layer have been revealed with primary direction of diffusion tensors. Complementary to the histology, the DTI of the fetal brain provides a valuable resource to understand the structural development of the entire brain. The resultant database will provide reference standards for diagnostic radiology of premature newborns.
人类大脑的解剖结构极其复杂，但它的起源却是一个简单的管状结构。在胎儿发育过程中，它具有显著的结构变化。揭示人类胎儿大脑发育不同阶段的详细解剖结构，不仅有助于理解这个高度有序的过程，还为检测遗传或环境因素引起的异常提供了线索。然而，这一时期人类大脑发育的解剖学研究却出人意料地匮乏，基于组织学的图谱最近才问世。弥散张量成像（DTI）是磁共振成像（MRI）的一项新技术，能够非侵入性地以高对比度描绘宏观解剖结构，并在微观水平上显示结构。在本文中，我们使用 DTI 衍生图像的对比度和 DTI 轨迹重建来探索胎儿脑白质。各向异性扩散张量揭示了大脑皮层中高度有序的结构。与组织学互补的是，DTI 为我们提供了一个理解整个大脑结构发育的宝贵资源。由此产生的数据库将为早产儿的放射诊断学提供参考标准。
