Dual red imaging: a novel endoscopic imaging technology visualizing thick blood vessels in the gastrointestinal wall

Abstract

Background Dual red imaging (DRI), a novel image-enhanced endoscopy (IEE) technology, has the potential to improve the visibility of blood vessels in deeper tissue using 600 nm and 630 nm wavelength lights in the red band. Aim To confirm the feasibility of DRI in visualization of vessels in deeper tissue and identify pathologically the features of blood vessels visualized by DRI. Methods Study 1: visibility of blood vessels was assessed by five observers in 137 pairs of DRI and white light imaging (WLI) images. The scores for the visibility of thick blood vessels were measured for randomized images and compared with the scoring template as a reference. The difference in visibility score between DRI and WLI was compared in each pair of images. Study 2: blood vessels detected only by DRI were examined pathologically using two pig stomachs. Results Study 1: The mean visibility scores of DRI and WLI for each observer were 1.69 – 2.26 and 1.31 – 1.67, respectively. The mean difference in visibility score and 95 % confidence interval for the five observers was 0.59 [0.46 – 0.72], 0.54 [0.40 – 0.68], 0.34 [0.18 – 0.49], 0.51 [0.36 – 0.66], and 0.71 [0.54 – 0.88]. The visibility was statistically significantly better in DRI than in WLI for all observers ( P < 0.0001). Study 2: three blood vessels were observed only by DRI. All of these blood vessels were located at a depth of 1000 – 1500 µm from the mucosal surface. The diameter of these blood vessels exceeded 80 – 200 µm. Conclusions DRI can feasibly detect thick blood vessels in the deep mucosa or submucosa of the gastrointestinal tract.

Haemostasis treatment using dual red imaging during endoscopic submucosal dissection: a multicentre, open-label, randomised controlled trial

“…Dual red imaging (DRI) is a novel endoscopic technology using two long-wavelength narrow-band lights (600 nm and 630 nm), developed in our institute in cooperation with Olympus (Tokyo, Japan) 13. Haemoglobin in blood more strongly absorbs orange light with a centre wavelength of 600 nm in comparison to light with a centre wavelength of 630 nm.…”

Utility of Dual Red Imaging for Endoscopic Hemostasis of Gastric Ulcer Bleeding

“…DRI is a new image-enhanced endoscopy technique that uses narrow-band light at two long wavelengths: 600 and 630 nm. DRI can detect thick blood vessels at a depth range of 1,000-1,500 μm from the mucosal surface of the gastrointestinal wall [1]. Naganuma et al [2] reported that DRI was useful to assess the severity of inflammation using the deep vascular pattern in patients with ulcerative colitis.…”

Clinically Available Optical Imaging Technologies in Endoscopic Lesion Detection: Current Status and Future Perspective

“…Red Dichromatic Imaging (RDI), also called dual red imaging (DRI), is a novel image-enhanced endoscopy technique, which was designed to enhance the visibility of blood vessels and bleeding sources in deeper tissue by using narrow-band light at two center wavelengths in the red band: 600 and 630 nm [ 27 , 28 ]. These wavelengths are able to detect thick blood vessels at a depth range of 1,000–1,500 μ m from the mucosal surface of the gastrointestinal wall [ 29 ], and they are between the wavelength of 576 nm (at which the light absorption coefficient reaches the maximum of the light absorption property of hemoglobin) and the wavelength of 730 nm (at which the light absorption coefficient reaches the minimum of the light absorption property of hemoglobin). Moreover, the light absorption of blood vessels at 600 nm is much stronger than that at 630 nm [ 29 ].…”

“…These wavelengths are able to detect thick blood vessels at a depth range of 1,000–1,500 μ m from the mucosal surface of the gastrointestinal wall [ 29 ], and they are between the wavelength of 576 nm (at which the light absorption coefficient reaches the maximum of the light absorption property of hemoglobin) and the wavelength of 730 nm (at which the light absorption coefficient reaches the minimum of the light absorption property of hemoglobin). Moreover, the light absorption of blood vessels at 600 nm is much stronger than that at 630 nm [ 29 ]. RDI utilizes green, amber, and red wavelengths to visualize bleeding points or deep blood vessels [ 28 ] ( Figure 8 ).…”