Department of Diagnostic and Interventional Imaging, University of Texas Medical School at Houston, Houston, Texas, USA.
Hum Brain Mapp. 2011 Jan;32(1):107-17. doi: 10.1002/hbm.21004.
In this communication, we extended a previously described and validated diffusion tensor imaging (DTI) method for segmenting whole brain cerebrospinal fluid (CSF) and gray and white matter (WM) tissue to provide regional volume and DTI metrics of WM tract and cortical and subcortical gray matter. This DTI-based regional segmentation was implemented using the statistical parametric mapping (SPM) toolbox and used the international consortium for brain mapping atlases and Montreal Neurological Institute brain templates. We used our DTI-based segmentation approach to calculate the left putamen volume in a cohort of 136 healthy right-handed males and females aged 15.8-62.8 years. We validated our approach by demonstrating its sensitivity to age-related changes of the putamen. Indeed, our method found that the putamen volume decreased with age (r = -0.30; P < 0.001) while the corresponding fractional anisotropy (FA) increased with advancing age (r = 0.5; P < 0.00001). It is then demonstrated, on a subset of our cohort (n = 31), that the putamen volume obtained by our method correlated with measurements obtained from FreeSurfer (r = 0.396, P < 0.05). Our novel approach increases the information obtained with a DTI examination by providing routine volumetry measure, thereby eliminating separate scans to obtain volumetry data. In addition, the labeled volumes obtained with our method have the potential to increase the accuracy of fiber tracking. In the future, this new approach can be automated to analyze large data sets to help discover noninvasive neuroimaging markers for clinical trials and brain-function studies in both health and disease.
在本通讯中，我们扩展了以前描述和验证过的扩散张量成像 (DTI) 方法，用于分割全脑脑脊髓液 (CSF) 和灰质和白质 (WM) 组织，以提供 WM 束和皮质及皮质下灰质的区域体积和 DTI 指标。这种基于 DTI 的区域分割是使用统计参数映射 (SPM) 工具箱实现的，并使用了国际脑图谱联合会和蒙特利尔神经学研究所的脑模板。我们使用基于 DTI 的分割方法来计算 136 名 15.8-62.8 岁的健康右利手男性和女性的左侧壳核体积。我们通过证明其对壳核年龄相关变化的敏感性来验证我们的方法。事实上，我们的方法发现壳核体积随年龄的增长而减小（r = -0.30；P < 0.001），而相应的各向异性分数（FA）随年龄的增长而增加（r = 0.5；P < 0.00001）。然后，在我们的队列的一个子集（n = 31）上证明，我们的方法获得的壳核体积与 FreeSurfer 获得的测量值相关（r = 0.396，P < 0.05）。我们的新方法通过提供常规体积测量值来增加 DTI 检查获得的信息量，从而消除了获得体积数据的单独扫描。此外，我们的方法获得的标记体积有可能提高纤维跟踪的准确性。在未来，这种新方法可以自动化，以分析大型数据集，帮助发现临床试验和健康与疾病中的脑功能研究的无创神经影像学标志物。
