Gray matter connectivity can be described in terms of its topographical organization, but the differential role of white matter connections underlying that organization is often unknown. In this study, we propose a method for unveiling principles of organization of both gray and white matter based on white matter connectivity as assessed using diffusion magnetic ressonance imaging (MRI) tractography with spectral embedding gradient mapping. A key feature of the proposed approach is its capacity to project the individual connectivity gradients it reveals back onto its input data in the form of projection images, allowing one to assess the contributions of specific white matter tracts to the observed gradients. We demonstrate the ability of our proposed pipeline to identify connectivity gradients in prefrontal and occipital gray matter. Finally, leveraging the use of tractography, we demonstrate that it is possible to observe gradients within the white matter bundles themselves. Together, the proposed framework presents a generalized way to assess both the topographical organization of structural brain connectivity and the anatomical features driving it.

中文翻译：

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纤维束成像数据的连通性梯度：管道和示例应用程序

灰质连接可以用其拓扑组织来描述，但该组织背后的白质连接的不同作用通常是未知的。在这项研究中，我们提出了一种基于白质连接性的揭示灰质和白质组织原理的方法，该方法使用具有光谱嵌入梯度映射的扩散磁共振成像（MRI）纤维束成像进行评估。该方法的一个关键特征是它能够以投影图像的形式将其显示的各个连接梯度投影回其输入数据，从而允许人们评估特定白质束对观察到的梯度的贡献。我们展示了我们提出的管道识别前额叶和枕叶灰质连接梯度的能力。最后，利用纤维束成像技术，我们证明可以观察白质束本身内的梯度。总之，所提出的框架提出了一种通用方法来评估结构性大脑连接的拓扑组织和驱动它的解剖特征。