Brain Connectivity Exposed by Anisotropic X-ray Dark-field Tomography

Matthias Wieczorek,Daniela Pfeiffer,Florian Schaff,Franz Pfeiffer,Tobias Lasser,Christoph Jud

doi:10.1038/s41598-018-32023-y

Matthias Wieczorek, Daniela Pfeiffer + Show 4 more

Open Access

https://doi.org/10.1038/s41598-018-32023-y

Copy DOI

Abstract

To understand the interaction of different parts of the human brain it is essential to know how they are connected. Such connections are predominantly related to the brain’s white matter, which forms the neuronal pathways, the axons. These axons, also referred to as nerve fibers, have a size on the micrometer scale and are therefore too small to be imaged by standard X-ray systems. In this paper, we use a grating interferometer and a method based on Anisotropic X-ray Dark-field Tomography (AXDT) with the goal to generate a three-dimensional tomographic reconstruction of these functional structures. A first preclinical survey shows that we successfully reconstruct the orientations of the brain fibers connectivity with our approach.

Highlights

The gold standard for imaging these fibers is diffusion tensor imaging (DTI)[6] and related but improved methods such as q-ball imaging[7]
Aiming at tomographic reconstruction of this anisotropic signal, we recently proposed a method called Anisotropic X-ray Dark-Field Tomography (AXDT) in[29], based on the previous work performed by Malecki et al.[30] and Vogel et al.[31]
In order to show the potential of Anisotropic X-ray Dark-field Tomography (AXDT) for brain connectivity applications in a first proof-of-principle feasibility study, we investigated a sample from the region of the cerebellum in a human brain. (Fig. 1B)[32] shows the location of the cerebellum on the left side

Summary

Introduction

The gold standard for imaging these fibers is diffusion tensor imaging (DTI)[6] and related but improved methods such as q-ball imaging[7]. In Fig. 1A) we illustrate such a grating-based X-ray imaging setup, which consists of a standard X-ray CT setup with three additional gratings, enabling the simultaneous extraction of the additional phase-contrast[20] and dark-field-contrast[19] signals. It has been shown that, in particular, the dark-field signal is correlated to (ultra-) small angle X-ray scattering[21] of the aligned micro- and nano-structures in the sample.

Results

Conclusion