Generalized diffusion tensor imaging and analytical relationships between diffusion tensor imaging and high angular resolution diffusion imaging
Generalized diffusion tensor imaging and analytical relationships between diffusion tensor imaging and high angular resolution diffusion imaging
复制标题
DOI：
10.1002/mrm.10596
复制
发表时间：
2003-11-01
影响因子：
3.3
通讯作者：
Mareci, TH
中科院分区：
文献类型：
--
作者：
Özarslan, E;Mareci, TH
提出了一种绘制组织中扩散率分布的新方法。 Bloch-Torrey 方程经过修改，包含具有任意阶笛卡尔张量的扩散项。求解该方程可给出量化复杂几何形状中的扩散衰减的广义 Stejskal-Tanner 公式的表达式。这使得计算高阶张量的分量成为可能，而无需使用计算困难的球谐变换。推导了传统（等级 2）DT 成像 (DTI) 测量的扩散张量 (DT) 分量与高角分辨率扩散成像 (HARDI) 方法测量的扩散率 3D 分布之间的一般理论关系。此外，HARDI 的球形张量分量与 2 阶 DT 相关。还介绍了高阶和低阶笛卡尔 DT 之间的关系。通过模拟证明了传统的 2 阶张量模型的不足，并将该方法应用于自旋回波 HARDI 实验中收集的切除大鼠大脑数据。 (C) 2003 Wiley-Liss, Inc.
A new method for mapping diffusivity profiles in tissue is presented. The Bloch-Torrey equation is modified to include a diffusion term with an arbitrary rank Cartesian tensor. This equation is solved to give the expression for the generalized Stejskal-Tanner formula quantifying diffusive attenuation in complicated geometries. This makes it possible to calculate the components of higher-rank tensors without using the computationally-difficult spherical harmonic transform. General theoretical relations between the diffusion tensor (DT) components measured by traditional (rank-2) DT imaging (DTI) and 3D distribution of diffusivities, as measured by high angular resolution diffusion imaging (HARDI) methods, are derived. Also, the spherical tensor components from HARDI are related to the rank-2 DT. The relationships between higher- and lower-rank Cartesian DTs are also presented. The inadequacy of the traditional rank-2 tensor model is demonstrated with simulations, and the method is applied to excised rat brain data collected in a spin-echo HARDI experiment. (C) 2003 Wiley-Liss, Inc.