Present and future status of flexible spectral imaging color enhancement and blue laser imaging technology

Abstract

The usefulness of flexible spectral imaging color enhancement (FICE) has been reported for evaluating the esophagus, stomach, and small and large intestine. Higher contrast is shown between cancer and the surrounding mucosa in the esophagus and stomach and may facilitate the detection of gastric cancers missed by white light imaging alone. The surface patterns of gastric mucosa are clearly visualized in non-malignant areas but are irregular and blurred in malignant areas, leading to clear demarcation. Capsule endoscopy with FICE detects angiodysplasia and erosions of the small intestine. The surface and vascular pattern with FICE is useful for the differential diagnosis of colorectal polyps. However, FICE remains somewhat poor at visualizing mucosal microvasculature on a tumor surface. Narrow-band imaging (NBI) is dark in observing whole gastric mucosa and poor at visualizing mucosal microstructure. Blue laser imaging (BLI) has the potential to resolve these limitations. Narrow-band laser light combined with white light shows irregular microvessels on both differentiated and undifferentiated gastric cancer similar to those using NBI. In addition, irregular surface patterns including minute white zones are clearly seen on the uneven surface of differentiated lesions, resulting in exclusion of undifferentiated lesions. Using both distant and close-up views, a high contrast between green intestinal metaplasia and brown gastric cancer may lead to early detection of gastric cancers and determination of a demarcation line. BLI produces high-contrast images in esophageal cancer with clear vision of intrapapillary capillary loops and also predicts the histopathological diagnosis and depth of invasion in colorectal neoplasms.

Diagnostic ability of magnifying endoscopy with blue laser imaging for early gastric cancer: a prospective study

“…The combination of strong 410-nm laser light, weak 450-nm laser light, and fluorescent light enables blue laser imaging (BLI) via narrow-band light observation. Magnifying endoscopy with BLI (M-BLI) is useful for evaluating mucosal surface information such as surface blood vessel and structure patterns [13][14][15][16].…”

The Usefulness of an Intra-Oropharyngeal U-turn Method using Trans-Nasal Endoscopy for Detecting Superficial Squamous Cell Carcinoma of the Base of the Tongue

“…BLI may be able to compensate for FICE because it uses narrow-band laser light combined with white light. Indeed BLI endoscopy has been shown to produce a new type of bright, high-resolution images of the digestive tract mucosa [9][10].…”

“…It is equipped with not only a white light observation but also a new narrow-band light observation function that takes advantage of the characteristics of laser light. Blue laser imaging observation (BLI) using the LASERIO system has successfully achieved a bright and clear image even at a distance [9][10]. In 2014, the EG-L580NW was released by Fuji film Corporation.…”

“…system (Fuji Film, Co., Tokyo, Japan) is the first gastrointestinal endoscopy system to use laser light as illumination [9][10]. It is equipped with a narrow-band light observation function that takes advantage of the characteristics of laser light, as well as a white light observation function.…”

Optical imaging of hemoglobin oxygen saturation using a small number of spectral images for endoscopic application

“…[36][37][38][39] Both techniques exploit narrow-band blue light to enhance the increase in abnormal microvessels in the superficial mucosa, which is one of the characteristic morphological features of cancerous lesions. The technique of StO 2 imaging described in this work, however, does not focus on enhancing such morphological features of the tissue, but aims at realizing a new realm of endoscopic functional imaging through visualizing tissue oxygenation.…”