Depth-resolved spectral imaging of rabbit oesophageal tissue based on two-photon excited fluorescence and second-harmonic generation

A novel depth-resolved spectral imaging based on two-photon excited fluorescence (TPEF) and second-harmonic generation (SHG) is developed for simultaneously investigating images and spectra at different depths within rabbit oesophageal tissues in backscattering geometry. Our results show that this method has a capability to identify the layered structures of oesophageal tissue including the keratinizing layer, epithelial cell layer and stromal layer, which are strongly correlated to tissue pathology. By integrating several system analysing tools, morphology and spectroscopy in different layers can be quantitatively obtained. Our findings demonstrate that this technique has the potential to provide more accurate and comprehensive information for the pathological diagnosis of tissues with stratified squamous epithelia.