Huazhong University of Science and Technology, Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Wuhan 430074, China.
J Biomed Opt. 2010 Mar-Apr;15(2):026008. doi: 10.1117/1.3369739.
Noninvasive detection of skin microcirculation is very significant for clinical diagnosis and therapy of peripheral vascular disease. In this study, an optical clearing method enables a laser speckle contrast imaging (LSCI) technique to image dermal blood flow through intact rat skin. The optical clearing effect of rat skin in vitro caused by a mixture of PEG-400 and Thiazone is evaluated by a commercially available spectrophotometer with an integrating sphere. A LSCI system is applied to image the dermal blood flow of in vivo rat skin after topical treatment of the agents. The results show that the reduced scattering coefficient (630 nm) is down to 60% of the initial value after 40 min of topical treatment of the mixture on skin in vitro. In vivo experimental results show that a 12-min treatment of the mixture on the epidermis can make the skin transparent and dermal vessels can be observed, while treatment with pure PEG-400 cannot. The process of skin optical clearing lasts, and the skin can be recovered by treatment of saline solution. Because optical clearing decreases the temporal contrast, dermal blood flow can be obtained by the laser speckle contrast imaging technique.
皮肤微循环的无创检测对周围血管疾病的临床诊断和治疗具有重要意义。在这项研究中，采用光学透明化方法使激光散斑对比成像（LSCI）技术能够透过完整的大鼠皮肤对真皮血流进行成像。通过配备积分球的商用分光光度计评估了 PEG-400 和噻唑啉混合物对体外大鼠皮肤的光学透明化效果。应用 LSCI 系统对经局部处理后的活体大鼠皮肤的真皮血流进行成像。结果表明，在体外皮肤表面局部处理混合物 40 分钟后，散射系数（630nm）降低至初始值的 60%。体内实验结果表明，混合物在表皮上处理 12 分钟可使皮肤透明，观察到真皮血管，而单独使用 PEG-400 处理则不行。皮肤光学透明化的过程持续进行，用生理盐水处理可使皮肤恢复。由于光学透明化降低了时间对比度，因此可以通过激光散斑对比成像技术获得真皮血流。
