Cortical thickness and central surface estimation
Cortical thickness and central surface estimation
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DOI：
10.1016/j.neuroimage.2012.09.050
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发表时间：
2013-01-15
期刊：
影响因子：
5.7
通讯作者：
Gaser, Christian
中科院分区：
文献类型：
--
作者：
Dahnke, Robert;Yotter, Rachel Aine;Gaser, Christian
人类大脑皮层的几个特性，例如，已经发现皮质厚度和脑回化与神经精神疾病的进展相关。大脑结构和功能之间的关系具有广泛的潜在用途，特别是在临床环境中，前提是从神经成像数据中提取大脑皮层的合适表示的鲁棒方法可用。一种这样的表示是大脑皮层的计算定义的中央表面（CS）。以前的半自动重建这种表面的方法依赖于需要手动交互的图像分割程序，从而使它们容易出错，并使对非健康成年人大脑的分析复杂化。这些方法和厚度测量的验证通常仅针对仅覆盖少数标准病例的简单人工体模进行。在这里，我们提出了一种新的全自动方法，允许测量皮质厚度和重建的CS在一个步骤。该算法首先利用组织分割来估计WM距离，然后利用WM距离描述的邻域关系将局部极大值（等于皮层厚度）投影到其他GM体素上。这种基于投影的厚度（PBT）允许处理部分体积信息，脑沟模糊和脑沟不对称，而无需通过骨架或细化方法进行明确的脑沟重建。此外，我们介绍了一个验证框架，使用球形和大脑幻影，确认准确的CS建设和皮质厚度测量下的一组广泛的参数，几个厚度水平。结果表明，我们的方法的质量和计算成本是可比的，并可能是上级在某些方面，现有的方法。(C)2012 Elsevier Inc. All rights reserved.
Several properties of the human brain cortex, e.g., cortical thickness and gyrification, have been found to correlate with the progress of neuropsychiatric disorders. The relationship between brain structure and function harbors a broad range of potential uses, particularly in clinical contexts, provided that robust methods for the extraction of suitable representations of the brain cortex from neuroimaging data are available. One such representation is the computationally defined central surface (CS) of the brain cortex. Previous approaches to semi-automated reconstruction of this surface relied on image segmentation procedures that required manual interaction, thereby rendering them error-prone and complicating the analysis of brains that were not from healthy human adults. Validation of these approaches and thickness measures is often done only for simple artificial phantoms that cover just a few standard cases. Here, we present a new fully automated method that allows for measurement of cortical thickness and reconstructions of the CS in one step. It uses a tissue segmentation to estimate the WM distance, then projects the local maxima (which is equal to the cortical thickness) to other GM voxels by using a neighbor relationship described by the WM distance. This projection-based thickness (PBT) allows the handling of partial volume information, sulcal blurring, and sulcal asymmetries without explicit sulcus reconstruction via skeleton or thinning methods. Furthermore, we introduce a validation framework using spherical and brain phantoms that confirms accurate CS construction and cortical thickness measurement under a wide set of parameters for several thickness levels. The results indicate that both the quality and computational cost of our method are comparable, and may be superior in certain respects, to existing approaches. (C) 2012 Elsevier Inc. All rights reserved.