Yang Shanshan, Liu Kezhou, Yao Lin, Liu Kaiyuan, Weng Guoqing, Xu Kedi, Li Peng
State Key Lab of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Education Ministry, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Biomed Opt Express. 2019 Nov 14;10(12):6258-6271. doi: 10.1364/BOE.10.006258. eCollection 2019 Dec 1.
The optical attenuation coefficient (OAC) estimated using optical coherence tomography (OAC-OCT) offers a label-free 3D mapping of tissue infarction, but the physiological origin of the OAC contrast remains unclear. For effectively suppressing OAC fluctuations, we propose a hybrid (wavelength/angle) division multiplexing (HDM) method, which improved the OAC contrast by 70.7% in tissue phantoms. To test the feasibility of OAC-based infarction detection, triphenyltetrazolium chloride (TTC) staining was performed on fresh brain slices, and the TTC-defined infarction was used as the ground truth. Sharp OAC contrast was observed between the TTC-defined infarction (1.09 mm) and normal tissue (0.79 mm). The OAC infarction spatially matched well with the TTC-defined infarction. To further explore the physiological origin of OAC contrast in ischemic stroke at the cellular level, the dynamic changes in OAC were measured in the rat cortex over 3 weeks after photothrombosis (PT) occlusion and found significantly correlated with the changes in astrocytes and neurons acquired with hematoxylin and eosin (HE), glial fibrillary acidic protein (GFAP), and NeuN staining. These results suggest that OAC imaging enables non-invasive infarction detection and its contrast might originate from the changes in astrocytes and neurons in the chronic PT stroke model. The cellular responses revealed by OAC imaging would be essential for evaluating treatments and even developing novel therapies.
使用光学相干断层扫描（OAC-OCT）估算的光学衰减系数（OAC）可提供无标记的组织梗死三维映射，但OAC对比度的生理起源仍不清楚。为有效抑制OAC波动，我们提出了一种混合（波长/角度）分频复用（HDM）方法，该方法在组织模型中将OAC对比度提高了70.7%。为测试基于OAC的梗死检测的可行性，对新鲜脑切片进行了氯化三苯基四氮唑（TTC）染色，并将TTC定义的梗死作为金标准。在TTC定义的梗死（1.09毫米）和正常组织（0.79毫米）之间观察到明显的OAC对比度。OAC梗死在空间上与TTC定义的梗死匹配良好。为在细胞水平上进一步探索缺血性中风中OAC对比度的生理起源，在光血栓形成（PT）闭塞后3周内测量了大鼠皮层中OAC的动态变化，发现其与苏木精和伊红（HE）、胶质纤维酸性蛋白（GFAP）和NeuN染色获得的星形胶质细胞和神经元的变化显著相关。这些结果表明，OAC成像能够进行非侵入性梗死检测，其对比度可能源于慢性PT中风模型中星形胶质细胞和神经元的变化。OAC成像揭示的细胞反应对于评估治疗甚至开发新疗法至关重要。
