Autofluorescence ratio imaging of human colonic adenomas

摘要

Recently autofluorescence imaging (AFI) endoscopy, visualizing tissue fluorescence in combination with reflected light, has been adopted as a technique for detecting neoplasms in the colon and other organs. However, autofluorescence colonoscopy is not infallible, and improvement of the detection method can be expected to enhance the performance. Colonic mucosa contains metabolism-related fluorophores, such as reduced nicotinamide adenine dinucleotide, which may be useful for visualizing neoplasia in autofluorescence endoscopy. We examined sliced cross-sections of endoscopically resected tubular adenomas under a microscope. Fluorescence images acquired at 365-nm excitation (F_(365ex)) and 405-nm excitation (F_(405ex)), and reflectance images acquired at 550 nm (R550) were obtained. Fluorescence ratio (F_(365ex)/F_(405ex)) images and reflectance/fluorescence ratio (R_(550)/F_(405ex)) images were calculated from the acquired images. The fluorescence ratio images could distinguish adenomatous mucosa from normal mucosa more clearly than the reflectance/fluorescence ratio images. The results showed that the autofluorescence ratio imaging is a potential technique for increasing the diagnostic power of autofluorescence endoscopy.