Evaluation of the visibility of bleeding points using red dichromatic imaging in endoscopic hemostasis for acute GI bleeding (with video)

We aimed to clarify whether red dichromatic imaging (RDI), a new type of image-enhanced endoscopy, improves the visibility of bleeding points in acute GI bleeding (AGIB) compared with white-light imaging (WLI). Images and videos of bleeding points acquired with WLI and RDI during endoscopic hemostasis for AGIB were retrospectively compared. In images, the color difference between bleeding points and surrounding blood was analyzed. In videos, 4 expert and 4 trainee endoscopists evaluated the visibility on a scale of 1 (undetectable) to 4 (easily detectable). Furthermore, the correlation between the color difference and visibility score was evaluated. We analyzed 64 lesions. The color difference was significantly higher in RDI (13.11 ± 4.02) than in WLI (7.38 ± 3.68, P < .001). The mean visibility score for all endoscopists was significantly higher in RDI (3.12 ± .51) compared with WLI (2.72 ± .50, P < .001); this was also observed in experts (3.18 ± .51 vs 2.79 ± .54, P < .001) and trainees (3.05 ± .54 vs 2.64 ± .47, P < .001). The color difference and visibility score were moderately correlated for all endoscopists (γ = .56, P < .001) and for experts (γ = .53, P < .001) and trainees (γ = .57, P < .001). RDI improves the visibility of bleeding points in AGIB compared with WLI. RDI can help endoscopists at all levels of experience to recognize bleeding points by enhancing the color contrast relative to surrounding blood.