Fluorescence imaging in the upper gastrointestinal tract for detection of dysplastic changes

During endoscopy of the esophagus fluorescence images were recorded at a delay of 20 ns after pulsed laser excitation simultaneously with conventional reflected white light images. To label malignant cells (dysplasia, tumor) 5-aminolaevulinic acid was applied prior to fluorescence guided biopsy. In this way pre-malignant and malignant lesions were detected not seen previously during routine endoscopy.