Schneider Torben, Wheeler-Kingshott Claudia A M, Alexander Daniel C
NMR Unit, Department of Neuroinflammation, UCL Institute of Neurology, University College London, UK.
Med Image Comput Comput Assist Interv. 2010;13(Pt 1):623-30. doi: 10.1007/978-3-642-15705-9_76.
This work presents diffusion MR protocols that allow estimation of axonal parameters like diameter and density in the live human brain. Previous approaches demand very high field experimental systems or suffer from long acquisition times and are therefore impractical for use in clinical studies. We propose a method that significantly reduces scan time by making use of the a-priori known fibre orientation in structures with well defined single fibre (SF) organisation like the corpus callosum (CC) and produces protocols that can be performed in under 25 minutes on a standard clinical system. Results from a computer simulation experiment show that our SF protocols can generate parameter estimates with similar precision to previously proposed orientation invariant (OI) protocols. Furthermore, we acquire the 20 minute long SF protocol and the 1 hour long OI protocol in a scan/rescan study on two healthy subjects and compare the axonal parameter maps from both protocols.
这项工作展示了扩散磁共振协议，该协议能够估计活体人类大脑中轴突的参数，如直径和密度。先前的方法需要非常高场强的实验系统，或者存在采集时间长的问题，因此在临床研究中不实用。我们提出了一种方法，通过利用在具有明确单纤维（SF）组织的结构（如胼胝体（CC））中先验已知的纤维方向，显著减少扫描时间，并生成可以在标准临床系统上25分钟内完成的协议。计算机模拟实验结果表明，我们的SF协议能够生成与先前提出的方向不变（OI）协议精度相似的参数估计值。此外，我们在对两名健康受试者的扫描/重新扫描研究中获取了20分钟长的SF协议和1小时长的OI协议，并比较了两种协议的轴突参数图。
