Mapping human cortical areas in vivo based on myelin content as revealed by T1- and T2-weighted MRI.
Mapping human cortical areas in vivo based on myelin content as revealed by T1- and T2-weighted MRI.
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DOI：
10.1523/jneurosci.2180-11.2011
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发表时间：
2011-08-10
期刊：
影响因子：
--
通讯作者：
Van Essen DC
中科院分区：
文献类型：
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作者：
Glasser MF;Van Essen DC
非侵入性地绘制人类皮层区域的布局是神经科学的一个持续挑战。我们提出了一种基于髓磷脂含量的皮质区域定位的新方法，该方法由t1加权（T1w）和t2加权（T2w） MRI显示。该方法适用于不同的3T扫描仪和脉冲序列。我们使用T1w/T2w图像强度的比值来消除核磁共振相关图像强度偏差，提高髓磷脂的对比度噪声比。每个受试者的数据被映射到皮质表面，并使用基于表面的注册在个体之间对齐。组平均髓磷脂图的空间梯度提供了一个独立于观察者的测量髓磷脂含量在整个表面的急剧转变-即。假定的皮质面边界。我们发现髓磷脂图的梯度和已发表的概率细胞建筑学定义的皮层区域的梯度之间有很好的一致性，这些区域被注册到相同的基于表面的图谱中。对于其他皮质区域，我们使用已发表的解剖和功能信息对数十个皮质区域或候选区域进行推定鉴定。一般来说，初级和早期单峰联合皮层有大量髓鞘，而更高的多峰联合皮层有更轻的髓鞘，但在文献中也有明显的例外，我们的结果证实了这一点。髓磷脂图谱的整体模式也与皮层下白质髓鞘形成的发育、人类与猕猴相比的进化皮层面积扩张、人类出生后皮层扩张以及非人类灵长类动物的神经元密度图谱具有重要的相关性。
Non-invasively mapping the layout of cortical areas in humans is a continuing challenge for neuroscience. We present a new method of mapping cortical areas based on myelin content as revealed by T1-weighted (T1w) and T2-weighted (T2w) MRI. The method is generalizable across different 3T scanners and pulse sequences. We use the ratio of T1w/T2w image intensities to eliminate the MR-related image intensity bias and enhance the contrast to noise ratio for myelin. Data from each subject was mapped to the cortical surface and aligned across individuals using surface-based registration. The spatial gradient of the group average myelin map provides an observer-independent measure of sharp transitions in myelin content across the surface—i.e. putative cortical areal borders. We found excellent agreement between the gradients of the myelin maps and the gradients of published probabilistic cytoarchitectonically defined cortical areas that were registered to the same surface-based atlas. For other cortical regions, we used published anatomical and functional information to make putative identifications of dozens of cortical areas or candidate areas. In general, primary and early unimodal association cortices are heavily myelinated and higher, multi-modal, association cortices are more lightly myelinated, but there are notable exceptions in the literature that are confirmed by our results. The overall pattern in the myelin maps also has important correlations with the developmental onset of subcortical white matter myelination, evolutionary cortical areal expansion in humans compared to macaques, postnatal cortical expansion in humans, and maps of neuronal density in non-human primates.