Automatic Extraction of the Cingulum Bundle in Diffusion Tensor Tract-specific Analysis: Feasibility Study in Parkinson's Disease with and without Dementia
Automatic Extraction of the Cingulum Bundle in Diffusion Tensor Tract-specific Analysis: Feasibility Study in Parkinson's Disease with and without Dementia
复制标题
DOI：
10.2463/mrms.2012-0064
复制
发表时间：
2013-01-01
影响因子：
3
通讯作者：
Ohtomo, Kuni
中科院分区：
文献类型：
--
作者：
Ito, Kenji;Masutani, Yoshitaka;Ohtomo, Kuni
目的：束特异性分析(TSA)测量通过人工感兴趣区域(ROI)跟踪提取的特定纤维上的扩散参数，但TSA受手动操作要求、重复性差和耗时较高的限制。我们的目标是开发一种全自动的扣带束(CB)提取方法，并将该方法应用于帕金森病(PD)等神经行为障碍的TSA。材料和方法：介绍体素分类(VC)和自动扩散张量纤维跟踪(AFT)提取方法。VC方法直接提取CB，跳过了纤维跟踪步骤，而AFT方法使用来自自动选择的ROI的纤维跟踪。我们将VC和AFT的结果与3个操作员进行的手动扩散张量纤维跟踪(MFT)的结果进行了比较。我们从20名受试者(10名正常对照和10名帕金森氏病痴呆患者)的数据中量化了3种方法之间的Jaccard相似性指数。分别用VC、AFT和MFT三种方法计算15例NC、15例PD和15例PDD患者的前后位各向异性分数(FA值)。结果：AFT结果与MFT结果之间的Jaccard指数为0.72，与MFT的术者间Jaccard指数相近。但VC与MFT、VC与AFT之间的Jaccard指数均较低。因此，VC方法可分为3组(NC、PD和PDD)，而其他方法仅分为2组(NC、PD或PDD)。结论：对于帕金森病患者的TSA，VC方法比AFT和MFT方法提取CB更有用。此外，患者数据分析的结果表明，后部CB中FA的减少可能是监测PD和PDD的有用生物学指标。
Purpose: Tract-specific analysis (TSA) measures diffusion parameters along a specific fiber that has been extracted by fiber tracking using manual regions of interest (ROIs), but TSA is limited by its requirement for manual operation, poor reproducibility, and high time consumption. We aimed to develop a fully automated extraction method for the cingulum bundle (CB) and to apply the method to TSA in neurobehavioral disorders such as Parkinson's disease (PD).Materials and Methods: We introduce the voxel classification (VC) and auto diffusion tensor fiber-tracking (AFT) methods of extraction. The VC method directly extracts the CB, skipping the fiber-tracking step, whereas the AFT method uses fiber tracking from automatically selected ROIs. We compared the results of VC and AFT to those obtained by manual diffusion tensor fiber tracking (MFT) performed by 3 operators. We quantified the Jaccard similarity index among the 3 methods in data from 20 subjects (10 normal controls [NC] and 10 patients with Parkinson's disease dementia [PDD]). We used all 3 extraction methods (VC, AFT, and MFT) to calculate the fractional anisotropy (FA) values of the anterior and posterior CB for 15 NC subjects, 15 with PD, and 15 with PDD.Results: The Jaccard index between results of AFT and MFT, 0.72, was similar to the inter-operator Jaccard index of MFT. However, the Jaccard indices between VC and MFT and between VC and AFT were lower. Consequently, the VC method classified among 3 different groups (NC, PD, and PDD), whereas the others classified only 2 different groups (NC, PD or PDD).Conclusion: For TSA in Parkinson's disease, the VC method can be more useful than the AFT and MFT methods for extracting the CB. In addition, the results of patient data analysis suggest that a reduction of FA in the posterior CB may represent a useful biological index for monitoring PD and PDD.