Quantitative analysis along the pyramidal tract by length-normalized parameterization based on diffusion tensor tractography: Application to patients with relapsing neuromyelitis optica
Quantitative analysis along the pyramidal tract by length-normalized parameterization based on diffusion tensor tractography: Application to patients with relapsing neuromyelitis optica
复制标题
基于扩散张量束成像的长度归一化参数化沿锥体束的定量分析：在复发性视神经脊髓炎患者中的应用
DOI：
10.1016/j.neuroimage.2006.03.055
复制
发表时间：
2006-10-15
期刊：
影响因子：
5.7
通讯作者：
Chan, Piu
中科院分区：
文献类型：
--
作者：
Lin, Fuchun;Yu, Chunshui;Chan, Piu
在本研究中，我们引入了一种长度归一化的参数化方法，以建立不同受试者之间白质纤维束的解剖对应关系，并应用该方法研究无可见脑部病变的复发型视神经脊髓炎（RNMO）患者锥体束（PYT）是否存在异常扩散。在此方法中，利用弥散张量纤维束成像技术重建大脑脚最低层面和侧脑室最高层面之间的锥体束部分，以建立不同受试者之间的解剖对应关系。然后通过对其长度进行归一化，并将归一化后的长度等分为一定数量的段来进行参数化，从而建立沿锥体束不同受试者各段之间的可比性。从每一段获取特定纤维束的弥散指标，包括方向平均弥散率（D - av）、分数各向异性（FA）、轴向弥散率（λ(1)）和横向弥散率（λ(23)），进而获得这些指标沿锥体束的分布图。RNMO患者的D - av、FA和λ(23)分布图与健康对照组显著不同，尤其是在锥体束的下部。这种差异可能是由脊髓病变引起的继发性变性所致。总之，我们提出了一种长度归一化的参数化方法来建立锥体束的解剖对应关系。与现有方法相比，我们方法的一个主要优点是在弥散张量纤维束成像的基础上提供沿锥体束不同受试者之间的可比性，并使沿纤维束的定量分析成为可能。该方法还可用于对许多神经或精神疾病中两个明确解剖标志之间的其他白质纤维束进行定量分析。（c）2006爱思唯尔公司。保留所有权利。
In this study, we introduced a length-normalized parameterization method to establish anatomical correspondence of white matter fiber tracts across subjects and applied this method to investigate the presence of abnormal diffusion along the pyramidal tract (PYT) of relapsing neuromyelitis optica (RNMO) patients without visible brain lesions. In this approach, the part of the PYT between the lowest slice of the cerebral peduncle and the uppermost slice of the lateral ventricle was reconstructed to establish the anatomical correspondence across subjects using diffusion tensor tractography. Then it was parameterized by normalizing its length and dividing equally the normalized length into a certain number of segments, so that the comparability of each segment across subjects along the PYT was established. Tract-specific diffusion indices, including directionally averaged diffusivity (D-av), fractional anisotropy (FA), primary diffusivity (lambda(1)) and transverse diffusivity (lambda(23)), were obtained from each segment. Thus, the distribution maps of these indices along the PYT were obtained. The distribution maps of D-av, FA, and lambda(23) of RNMO patients were significantly different from those of healthy controls, especially in the lower part of the PYT. The differences may be caused by secondary degeneration to lesions in the spinal cord. In conclusion, a length-normalized parameterization method is proposed to establish anatomical correspondence for the PYT. Compared with existed methods, a major merit of our method is to provide comparability across subjects along the PYT on the basis of diffusion tensor tractography and to make it possible for the quantitative analysis along the fiber tract. This method can also be used to quantitatively analyze other white matter fiber tracts between two definite anatomic landmarks in many neurological or psychiatric diseases. (c) 2006 Elsevier Inc. All rights reserved.