Nonlinear Spectral Resolved Imaging Technique Of Layer Structures In The Epithelial Tissues

A nonlinear spectral resolved imaging technique based on two-photon excited fluorescence (TPEF) and second-harmonic generation (SHG) combines the advantages of two-photon microscopy with that of spectral measurement technique. It can simultaneously obtain tissue images and spectra at different depths in backscattering geometry. This method has a capability of providing more accurate and comprehensive information for physiological and pathological diagnosis of tissues clinically and non-invasively. In this thesis, epithelial tissues including rabbit oesophageal tissue, mouse cervical tissue and mouse bronchial wall were investigated. By integrating several system analysing tools, morphology and spectroscopy in different layers can be quantitatively obtained, and some important parameters such as an optimal excitation wavelength for the estimation of epithelial cellular metabolism and the most suitable excitation wavelength for acquiring high contrast images of collagen and elastin and monitoring the change of collagen SHG over elastin TPEF in the stromal layer were studied. Our findings demonstrate that this technique has great value to be applied in vivo real-time diagnosis and therapy in diseases of epithelial tissues.