The present invention is directed to a novel multi-spectral contrast
agent-enhanced polarized light imaging technique that enables rapid
imaging of large tissue fields. The imaging device includes a tunable
monochromatic light source and a CCD camera. Linear polarizers are placed
into both the incident and collected light pathways in order to limit the
measurement volume to the superficial tissue layers. To enhance the tumor
contrast in the image, aqueous solutions of toluidine blue or methylene
blue are topically applied.