Beyond backscattering: optical neuroimaging by BRAD.
Beyond backscattering: optical neuroimaging by BRAD.
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DOI：
10.1364/boe.9.002476
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发表时间：
2018-06-01
影响因子：
3.4
通讯作者：
Baumann B
中科院分区：
文献类型：
--
作者：
Eugui P;Lichtenegger A;Augustin M;Harper DJ;Muck M;Roetzer T;Wartak A;Konegger T;Widhalm G;Hitzenberger CK;Woehrer A;Baumann B
光学相干层析成像（OCT）是一种强大的生物医学快速体成像技术。传统OCT系统的明场成像方法基于直接反向散射光的检测，从而放弃了角散射分布中包含的丰富信息。在这里，我们证明了少模光纤（FMF）的独特功能，使同时亮场和暗场（布拉德）成像OCT。由于背散射光拾取的不同模式的FMF取决于角散射图案，我们获得访问不同组织的定向散射签名通过解耦照明和检测路径。我们利用FMF的独特模式传播特性与现代波长扫描激光器提供的长相干长度相一致，以实现将不同模式响应复用到组合OCT断层图像中。我们证明了布拉德传感用于区分不同尺寸的微粒，并展示了BRAD-OCT成像的性能，其具有增强的对比度，用于胶质母细胞瘤中的离体肿瘤组织和阿尔茨海默病中的神经炎斑块。
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.