Noninvasive native fluorescence imaging of head and neck tumors.

Fluorescence images were acquired from ex vivo head and neck tumor specimens. The excitation and emission wavelength combinations were selected to image emission from native tissue fluorophores (collagen, tryptophan, elastin and nicotinamide adenine dinucleotide). Two dimensional intensity ratio maps were generated from the fluorescence images and compared to histology images. The ratio maps accurately distinguished the regions of tumor from normal tissue in the specimens. Additional features, such as collagen capsules, blood vessels, mucus glands and muscles were evident in the fluorescence images.