Beyond backscattering: Optical neuroimaging by BRAD
Abstract
Optical coherence tomography (OCT) is a powerful technology for rapid volumetric imaging in biomedicine. The bright field imaging approach of conventional OCT systems is based on the detection of directly backscattered light, thereby waiving the wealth of information contained in the angular scattering distribution. Here we demonstrate that the unique features of few-mode fibers (FMF) enable simultaneous bright and dark field (BRAD) imaging for OCT. As backscattered light is picked up by the different modes of a FMF depending upon the angular scattering pattern, we obtain access to the directional scattering signatures of different tissues by decoupling illumination and detection paths. We exploit the distinct modal propagation properties of the FMF in concert with the long coherence lengths provided by modern wavelength-swept lasers to achieve multiplexing of the different modal responses into a combined OCT tomogram. We demonstrate BRAD sensing for distinguishing differently sized microparticles and showcase the performance of BRAD-OCT imaging with enhanced contrast for ex vivo tumorous tissue in glioblastoma and neuritic plaques in Alzheimer's disease.
Cite
@article{arxiv.1712.00361,
title = {Beyond backscattering: Optical neuroimaging by BRAD},
author = {Pablo Eugui and Antonia Lichtenegger and Marco Augustin and Danielle J. Harper and Martina Muck and Thomas Roetzer and Andreas Wartak and Thomas Konegger and Georg Widhalm and Christoph K. Hitzenberger and Adelheid Woehrer and Bernhard Baumann},
journal= {arXiv preprint arXiv:1712.00361},
year = {2018}
}