NEWLY DEVELOPED OPTIMAL BAND IMAGING SYSTEM FOR THE DIAGNOSIS OF EARLY GASTRIC CANCER

Background:  Magnifying narrow band imaging system is useful for the diagnosis of early gastric cancer. However, it is difficult for the operator of the scope to maintain the correct distance between the tip of the endoscope and the gastric mucosa for appropriate visualization. The newly developed optimal band imaging system can reconstruct good spectral images derived from ordinary endoscopic images and enhance the mucosal surface without magnification as well as with low magnification. This imaging technique is based on narrowing the bandwidth of the conventional image arithmetically, using spectral estimation technology. Methods:  We evaluated endoscopic features of 30 lesions with elevated-type, 32 lesions with depressed-type and two lesions with flat-type early gastric cancer using this new system. Results:  We found the best images in all cases of early gastric cancers by using a specific combination of the following three wavelengths available in this system: 470 nm for blue, 500 nm for green and 550 nm for red. The optimal band images showed the depressed-type early gastric cancer as reddish lesions distinct from the surrounding yellowish non-cancerous area, leading to a clear demarcation line between the cancerous and non-cancerous mucosa without magnification. Moreover, 30–40-fold magnified optimal band images showed a clearly irregular microvascular pattern or a microstructure pattern of the mucosal surface in all types of gastric cancers. Conclusion:  This new system can provide useful information for diagnosing various types of early gastric cancers without and with low magnification.