光學同調斷層掃瞄技術及於口腔疾病診斷應用

Abstract

光學同調斷層掃瞄是一種非侵入式、高解析度的生物醫學影像技術。解析度可以達到約1 至15 微米，相較於傳統的超音波更精細數十到數百倍，影像速度可以高達每秒鐘十萬次的A-scan；目前光學同調斷層掃瞄已經廣泛地應用在眼科的領域中。而在口腔癌的研究方面，光學同調斷層掃瞄也具有區別良性惡性口腔病變的潛力。 在這篇論文中，我們首先針對口腔下黏膜纖維化疾病提出兩種可以使用在光學同調斷層掃瞄影像中的診斷指標，包含上皮層厚度及固有層的強度標準差，其次，我們發展了一套可以針對光學同調斷層掃瞄影像臨床即時分析口腔癌前病變的軟體。 由於光學同調斷層掃瞄採用背向散射的同調干涉訊號解析出待測物的內部結構，因此，任何能夠增強同調背向散射的技術，可以增強光學同調斷層掃瞄影像對比，都能提昇影像品質，擴展光學同調斷層掃瞄之應用。而金奈米環具有獨特的表面電漿共振特性，可以加強散射及吸收，並且金具有良好的生物相容性，於是我們利用了金奈米環來提高影像對比度，我們讓其滲入豬脂肪組織中，以觀察金奈米環由於表面電漿共振而產生的吸收及散射特性。最後，我們採用光斑變化分析方法，探討金奈米粒子在老鼠肝臟組織中的擴散情形。

Optical Coherence Tomography (OCT) is a noninvasive, high resolution imaging technique for biomedical applications. OCT can provide images with resolution 1-15 microns in the longitudinal direction. OCT has been widely used in biomedical imaging, particularly in ophthalmology. In oral cancer study, the capability of OCT for imaging the underlying structures of both benign and malignant oral mucosa was also demonstrated. In this dissertation, we first propose two indicators, including epithelium thickness and laminar propria standard deviation, to diagnosis oral submucous fibrosis. Second, we propose a computer analysis procedure of OCT images for real-time oral pre-cancer diagnoses. OCT scanning uses the interfered backscattered coherent signal for retrieving sample structures. Therefore, any contrast agent, which can enhance coherent backscattering, can be used for increasing OCT image quality. We use the Au nanoring as the contrast agent because its localized surface plasmon properties have found broad applications in emission and absorption enhancements. The Au nanorings are delivered into pig adipose samples for OCT scanning to demonstrate the enhanced absorption and scattering behaviors of LSP resonance. And then, we track the resonant Au NR diffusion in a mouse liver tissue with OCT scanning.