Fluorescence video endoscopic system for early cancer detection

A video system is being developed to allow the detection of cancerous lesions that are too small to be accurately identified visually or with x-ray. The system makes use of standard endoscopes and provides a video display of both the color image and a false color fluorescence image, with automated switching between the two views. Excitation of the fluorescence marker, Heinatoporphyrin Derivative (HpD) , or it ' 5 purified form , diheinatoporphyrin ether! ester (DHE) , is provided by a krypton ion laser operating in the violet. A brief discussion of fluorescence diagnostic theory and a description of the prototype system, its clinical use , and performance is reviewed.