Correcting the detrimental effects of nonuniform intensity distribution on fiber-transmitting laser speckle imaging of blood flow.
Correcting the detrimental effects of nonuniform intensity distribution on fiber-transmitting laser speckle imaging of blood flow.
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DOI：
10.1364/oe.20.000508
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发表时间：
2012-01
期刊：
影响因子：
3.8
通讯作者：
Hongyan Zhang;Pengcheng Li;Nengyun Feng;Jianjun Qiu;Bing Li;W. Luo;Qingming Luo
中科院分区：
文献类型：
--
作者：
Hongyan Zhang;Pengcheng Li;Nengyun Feng;Jianjun Qiu;Bing Li;W. Luo;Qingming Luo
激光散斑空间对比度分析（LSSCA）由于具有高时间分辨率的优势，在监测血流的快速变化方面优于激光散斑时间对比度分析（LSTCA）。然而，当存在不均匀强度分布（例如光纤传输激光散斑成像）时，基于空间统计的LSSSA的应用可能会受到限制。在本研究中，我们提出了归一化激光散斑空间对比度分析（nLSSCA），以纠正不均匀强度分布对空间统计的不利影响。通过数值模拟和体模实验发现，只需十帧动态激光散斑图像就足以让nLSSCA实现有效校正。此外，nLSSSA 具有比 LSTCA 更高的时间分辨率来响应速度的变化。 LSSCA、LSTCA和nLSSSA均应用于光纤传输激光散斑成像系统，分别分析大鼠皮层皮质扩散抑制（CSD）期间皮质血流（CBF）的变化，结果表明nLSSCA可以更准确地检查CBF的变化。由于这些优点，nLSSCA 可能成为光纤传输/内窥镜激光散斑成像的潜在工具。
Laser speckle spatial contrast analysis (LSSCA) is superior to laser speckle temporal contrast analysis (LSTCA) in monitoring the fast change in blood flow due to its advantage of high temporal resolution. However, the application of LSSCA which is based on spatial statistics may be limited when there is nonuniform intensity distribution such as fiber-transmitting laser speckle imaging. In this study, we present a normalized laser speckle spatial contrast analysis (nLSSCA) to correct the detrimental effects of nonuniform intensity distribution on the spatial statistics. Through numerical simulation and phantom experiments, it is found that just ten frames of dynamic laser speckle images are sufficient for nLSSCA to achieve effective correction. Furthermore, nLSSCA has higher temporal resolution than LSTCA to respond the change in velocity. LSSCA, LSTCA and nLSSCA are all applied in the fiber-transmitting laser speckle imaging system to analyze the change of cortical blood flow (CBF) during cortical spreading depression (CSD) in rat cortex respectively, and the results suggest that nLSSCA can examine the change of CBF more accurately. For these advantages, nLSSCA could be a potential tool for fiber-transmitting/endoscopic laser speckle imaging.