Depth-resolved fluorescence spectroscopy of normal and dysplastic cervical tissue

A portable confocal system with the excitations at 355nm and 457nm was instrumented to investigate the depth-resolved fluorescence of cervical tissue. The study focused on extracting biochemical and morphological information carried in the depth-resolved signals measured from the normal squamous epithelial tissue and squamous intraepithelial lesions. Strong keratin fluorescence with the spectral characteristics similar to collagen were observed from the topmost keratinizing layer of all tissue samples. It was found that NADH and FAD fluorescence measured from the underlying non-keratinizing epithelial layer were strongly correlated to the tissue pathology. This study demonstrates that the depth-resolved fluorescence spectroscopy can potentially provide more accurate diagnostic information for determining tissue pathology.