Spectrally resolved fluorescence imaging of human colonic adenomas

Native fluorescence (autofluorescence) of human tissues can be a valuable s ource of diagnostic information for detecting premalignant and malignant le sions in the human body. Digital imaging of autofluorescence may be useful for localization of such lesions during endoscopic examinations. Tissue flu orescence of 31 adenomatous polyps obtained from 16 patients has been excit ed in vitro using the 325 nm line of a He-Cd laser. Digital images of the a utofluorescence are recorded in six spectral bands. This study provides new data about the spatial distributions of autofluorescence intensities emitt ed in different spectral bands by colonic adenomatous lesions and normal co lonic mucosa. Areas characterized by autofluorescence intensity lower than in normal mucosa are found for a majority of the polyps under study. The ob served patterns of spatial distribution differ for the different spectral b ands and for different polypoid lesions. No inverse correlation is found be tween the emission intensity and the thickness of colonic mucosa. The resul ts indicate the spectral bands most useful for diagnostic applications and demonstrate the complexity of the optical processes involved in shaping bot h the spectra and intensities of the autofluorescence. (C) 1999 Elsevier Sc ience S.A. All rights reserved.