An endoscope having an optical guide that is optically coupled to a first
broadband light source and a second laser light source that emits light
at a wavelength in a range of 350 nm to 420 nm. The endoscope has an
image sensor at a distal end and collects a reflectance image including
red, green and blue components with the image sensor in response to
illumination by said broadband light source. The image sensor also
collects an autofluorescence image having a blue component, a green
component and a red component. A processor processes the fluorescence
image by determining a ratio of the fluorescence image and the
reflectance image to provide a processed fluorescence image.