Visualizing Skin Lesions with Stokes’ Polarimeter Based Second Harmonic Generation Microscopy

• Main Authors: Wen-Zhe Wang, 王文哲
• Other Authors: Fu-Jen Kao
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/92857260609353417350

碩士 === 國立陽明大學 === 生醫光電研究所 === 101 === Dermatological diagnosis is usually done by visual examination or detailed biopsies with microscopy on the targeted specimen. The processes usually lack quantitative analysis, and may be time consuming if tissue culturing is required. This study focuses on the biopsy of scar tissues of human skin, including normal, hypertrophic, and keloid tissues, by analyzing the polarization states of second harmonic signals from the tissues with the novel four-channel Stokes’ polarimeter. A mode-locked Ti-sapphire laser, which generated 200 fs ultra-short pulses, is used to induce second harmonic signal from the collagen of the skin tissues. In this way, the potential photo-toxicity on fluorophores is greatly reduced. The samples are irradiated with the incident beam of various polarization states. The resulting polarization parameters reconstructed from the SHG signals reveal unique collagen arrangements in the tissues. Our results show that the different skin lesions are clearly distinguishable through the polarization imaging of the collagen structure. The noninvasive and enhanced contrast enabled by polarization has the potential for in-depth biomedical analysis and may find invaluable applications in clinical diagnosis.