ENDOSCOPIC DIAGNOSIS OF IIB TYPE OF EARLY GASTRIC CANCER AND STUDIES OF COLOR ANALYSIS

Abstract

The frequency of IIb type of early gastric cancer is increasing in accordance with the improvement of diagnostic technique with the development of Endoscopic system. But it is not so easy to detect typical IIb type which is flat lesion and there is a difficulty in an X-ray, endoscopic and histological examinations. In the endoscopic finding of IIb type of early gastric cancer, tiny color difference from the normal mucosa was considered to be most important, and we can divide into two types ; Red type and white type. Therefore, it is very important for the diagnosis of IIb type of early gastric cancer to find the difference in tone of the color very precisely. It is possible to identify the IIb type of early gastric cancer correctly, if we could describe this color difference objectively. From this point of view, the following color analysis of spectrum of gastric mucosa was attempted using the rapid scan spectrophotometer/color difference mether (CMS-1200 block diagram system). Basic spectral curve of the normal gastric mucosa has first peak in 500 nm and second higher peak in 690-700 nm. The color analysis was performed on gastric ulcer, IIb type and IIc type of early gastric cancer, and advanced gastric cancer. The analysis curve of IIb (white type) revealed complete difference in color from atrophic mucosa. From this trial, the detection of IIb type of early gastric cancer using color analysis may be easier than single endo-scopical examination. Recently we have been able to analize RGB of the color of the gastric mucosa by video endoscope. Therefore, an introduction of the color analysis into the computer of the video endoscopy system may make it possible to detect the difficult lesions and endoscopic autodiagnosis might become possible in future.