Magnifying Endoscope Diagnosis and NBI Diagnosis in Colorectal Neoplasm

Abstract

Recently, endoscopic diagnosis has been developed with new endoscope techniques and equipment, and especially the magnifying function and the narrowband imaging (NBI) system. The magnifying endoscope can observe the surface microstructure of colonic mucosa (pit pattern) after dye-spraying and enlarging 100 times or more. The pit pattern is divided into six categories, and we can distinguish between nonneoplasm/neoplasm, benign or malignant, and mucosal or invasive cancer. The newly available NBI system is based on the modification of spectral features with an optical color separation filter narrowing the bandwidth (415 nm and 540 nm) of spectral transmittance. The endoscopic image is reproduced in the processor with this information, and we can see the capillary network of superficial mucosa by using the magnifying endoscope. The capillary network pattern are divided into three categories, and correspond to pathological features. Many Japanese researchers are investigating capillary vessel patterns from various standpoints owing to the newly developed qualities of endoscopic diagnosis. In addition, NBI has enhanced the effectiveness of examinations to evaluate the mucous membrane, and helped the discovery of dysplasia and colitic cancer in inflammatory bowel disease. Both the magnifying endoscope and the NBI system are very important tools that have been researched and invented in Japan. These developments have greatly improved endoscopic diagnosis.