The use of videoendoscopy in the study of fluorescence

Diagnosis of malignancies by means of fluorescence detection is effected, at present, using fiberoptic endoscopes. Difficulties in the detection of fluorescence arise from the low fluorescent efficiency of the most widely used drug (hematoporphyrin derivative), and from the loss of intensity of the signal within the fiberoptic bundles and the ocular lens of the fiberendoscope. The electronic video-endoscope, carrying a microchip camera at its tip, permits a more sensitive detection of fluorescence, since the signal is drawn directly from the cavities. Furthermore the electronic image, stored in a computer, can be manipulated to produce a more enhanced contrast between the fluorescence of normal and malignant tissues. An example of electronic manipulation would be the subtraction of the image obtained under green light excitation from that obtained under violet light excitation.