Endoscopic diagnosis of reflux-oesophagitis with special regard to computerized image processing

Abstract: Endoscopic diagnosis of reflux-oesophagitis with special regard to computerised image processing by Hanne Witt Department of Surgery, Division for Diagnostic Radiology, Karolinska Institute and Hospital, S-17174 Stockholm, Sweden.The advent of the videoendoscope is an important step in endoscope technology and it is ofvital importance in the linkage between endoscopy and computers. The Charge CoupledDevice ( CCD ) of an electric videoendoscope transforms the light reflected from the mucosainto electric signals. These signals are in turn converted in the videoprocessor unit into a digitalimage which is presented on the monitor. The digital image is suitable for different kinds ofimage processing with the mann purpose to enhance the information stored in the image.Pathological mucosa has very often subjectively a colour ( objectively; difference in absorptionspectrum ) which is different from that of normal mucosa. Such differences can be analysedquantitatively by means of a colorimetric image processing.The generally most accepted methods for diagnosing reflux oesophagitis are endoscopy withbiopsy, pH-measurement and manometry. No universally accepted classification system for theendoscopic staging of reflux oesophagitis exists, but the Savary-Miller classification is the mostcommonly used. Computerized quantification of the extent of the mucosal lesions by means ofcolour analysis of the endoscopic images could allow us to establish a more objectiveclassification system of reflux oesophagitis.The important role of the microcirculation in the mucosa in the gastrointestinal tract has beenemphasized in the development and healing of peptic ulcerations and other gastrointestinaldiseases. An estimation of the mucosal hemoglobin content appears to by important inelucidating the role of the mucosal blood flow in the pathophysiology of gastrointestinaldiseases. The greater part of the pigments in the mucosa in the gastrointestinal tract arehemoglobin. Light from the endoscope is composed of the three primary colours ( red, greenand blue ). The hemoglobin will absorb the green light but reflect most of the red light.Therefore it is possible to estimate the hemoglobin content in the mucosa using the differenceof the intensity of the red and green light. Endoscopic real-time analysis of the mucosalhemoglobin content in the oesophageal mucosa can by done by combining reflectancespectrophotometry with electronic endoscopy and an image processing system.Keywords: endoscopy, reflux esophagitis, computerized image processing, mucosalhemoglobin content, chromoscopyLanguage: EnglishStockhohm 1995 ISBN 95-628-1783-3