Tournier J-Donald, Calamante Fernando, Gadian David G, Connelly Alan
Radiology & Physics Unit, Institute of Child Health, University College London, and Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom.
Neuroimage. 2003 Sep;20(1):276-88. doi: 10.1016/s1053-8119(03)00236-2.
A novel technique is presented for estimating white matter connectivity in vivo using diffusion-weighted magnetic resonance imaging. The concept of a fibre orientation density function (ODF) is described, which characterises the uncertainty in the orientation of the underlying white matter fibres, given the set of diffusion-weighted signal intensities at the point of interest. The proposed algorithm is based on the evolution of a front from a seed region, using the information provided by the fibre ODF. Each point reached by the front is assigned an index of connectivity with the seed region. The algorithm was used to track various major white matter fibre pathways in two data sets acquired on the same healthy adult volunteer over separate occasions. Example tracks are shown to illustrate some of the properties of the algorithm, such as robustness to noise and branching capability. Finally, the dependence of the algorithm on the model used to derive the fibre ODF is discussed.
本文提出了一种利用扩散加权磁共振成像在体估计白质连通性的新技术。文中描述了纤维取向密度函数（ODF）的概念，它根据感兴趣点处的扩散加权信号强度集来表征潜在白质纤维取向的不确定性。所提出的算法基于前沿从种子区域的演化，利用纤维ODF提供的信息。前沿到达的每个点都被赋予与种子区域的连通性指数。该算法用于在不同时间从同一名健康成年志愿者获取的两个数据集中追踪各种主要的白质纤维束。给出了示例轨迹以说明该算法的一些特性，如对噪声的鲁棒性和分支能力。最后，讨论了该算法对用于推导纤维ODF的模型的依赖性。
