Introduction. Endoscopy is the primary method for visualizing the mucous membranes of the gastrointestinal tract, used for diagnosing and treating diseases. Traditional endoscopy, based on white-light optics, provides images of the examined tissues but has limited ability to detect early neoplastic changes. Advances in endoscopic methods have led to the development of narrow-band imaging (NBI, i-SCAN), which enhances visualization of vascular and tissue structures, thereby increasing diagnostic accuracy [1, 2].