Tract Specific Reproducibility of Tractography Based Morphology and Diffusion Metrics
Tract Specific Reproducibility of Tractography Based Morphology and Diffusion Metrics
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DOI：
10.1371/journal.pone.0034125
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发表时间：
2012-04-02
期刊：
影响因子：
3.7
通讯作者：
Backes, Walter H.
中科院分区：
文献类型：
--
作者：
Besseling, Rene M. H.;Jansen, Jacobus F. A.;Backes, Walter H.
引言：纤维束成像的可重复性对于确定其对病理异常的敏感性非常重要。纤维束形态的可重复性尚未得到系统的研究，最近开发的纤维束造影对比剂纤维束密度成像（TDI）尚未评估在道specific level.Materials和方法：扩散张量成像（DTI）和概率约束球面去卷积（CSD）纤维束成像在9名健康受试者进行了两次。纤维束成像是基于共同的空间种子和目标区域，并进行了几个主要的白色物质束。将纤维束描记图转换为纤维束分割，并使用Dice相似系数（DSC）评估纤维束形态的会话间再现性。变异系数（COV）和组内相关系数（ICC）计算以下道指标：各向异性分数（FA），表观扩散系数（ADC），体积和TDI。分析进行近端（深白色物质）和扩展（包括皮质下白色物质）道segmentations.Results：近端DSC值为0.70-0.92。与近端分段相比，延长段的DSC值低5-10%。FA、ADC、volume和TDI的COV/ICC值分别为1-4%/0.65-0.94、2-4%/0.62-0.94、3-22%/0.53-0.96和8-31%/0.48-0.70，近端节段的COV值较低，ICC值较高。FA和ADC具有相对低的COV和相对高的ICC，表明具有临床潜力。体积有较高的COV，但其中度到高ICC值在大多数路段仍然表明受试者的区分能力。道TDI具有高COV和相对低的ICC，这反映了不利的再现性。
Introduction:The reproducibility of tractography is important to determine its sensitivity to pathological abnormalities. The reproducibility of tract morphology has not yet been systematically studied and the recently developed tractography contrast Tract Density Imaging (TDI) has not yet been assessed at the tract specific level.Materials and Methods: Diffusion tensor imaging (DTI) and probabilistic constrained spherical deconvolution (CSD) tractography are performed twice in 9 healthy subjects. Tractography is based on common space seed and target regions and performed for several major white matter tracts. Tractograms are converted to tract segmentations and inter-session reproducibility of tract morphology is assessed using Dice similarity coefficient (DSC). The coefficient of variation (COV) and intraclass correlation coefficient (ICC) are calculated of the following tract metrics: fractional anisotropy (FA), apparent diffusion coefficient (ADC), volume, and TDI. Analyses are performed both for proximal (deep white matter) and extended (including subcortical white matter) tract segmentations.Results: Proximal DSC values were 0.70-0.92. DSC values were 5-10% lower in extended compared to proximal segmentations. COV/ICC values of FA, ADC, volume and TDI were 1-4%/0.65-0.94, 2-4%/0.62-0.94, 3-22%/0.53-0.96 and 8-31%/0.48-0.70, respectively, with the lower COV and higher ICC values found in the proximal segmentations.Conclusion: For all investigated metrics, reproducibility depended on the segmented tract. FA and ADC had relatively low COV and relatively high ICC, indicating clinical potential. Volume had higher COV but its moderate to high ICC values in most tracts still suggest subject-differentiating power. Tract TDI had high COV and relatively low ICC, which reflects unfavorable reproducibility.