Linked color imaging for the detection of early gastrointestinal neoplasms

Abstract

In routine upper and lower gastrointestinal endoscopy, overlooking neoplastic lesions is inevitable even for well-trained endoscopists. Various methods have been reported to improve the detection of gastrointestinal neoplasms including chromoendoscopy, special endoscopes, and processor and image enhanced technologies. Equipment-based image enhanced endoscopy (e-IEE) using narrow band imaging (NBI) and blue laser imaging (BLI) is useful to characterize known lesions with magnification at a close-up view. However, they are not useful for the early detection of superficial, pale neoplasms, or both because of the weak image at a distant view in a wide lumen such as the stomach or colon. Linked color imaging (LCI) is a novel pre- and post-processing technology developed by Fujifilm Corporation that has sufficient brightness to illuminate a wide lumen. LCI delineates early gastric cancers as orange-red and intestinal metaplasia as purple. LCI improves the adenoma detection rate in the colon and decreases the polyp miss rate. LCI contributes to the detection of superficial lesions throughout the gastrointestinal tract by enhancing the color contrast between the neoplasm and the surrounding mucosa. LCI can distinguish them by their specific color allocation based mainly on the distribution of capillaries. The authors believe that moving forward, LCI should be used in routine upper and lower gastrointestinal endoscopy.

Keywords: colon polyp; diagnosis; endoscopy; image enhanced endoscopy; linked color imaging.

Figure 1.

(a) Pre-processing by linked color imaging (LCI) technology. In neoplastic lesions, the capillaries are located in the shallow layer. 410 nm violet light is absorbed by capillaries, therefore, the violet light is not visible and the neoplastic lesion appears red. In inflammatory lesions, capillaries are in the deep layer. 410 nm violet light is not absorbed, and the lesion appears violet. (b) Post-processing by LCI technology. The colors obtained are separated and reallocated for color enhancement. This makes red and white lesions become more red and more white, respectively. WLI: white light imaging.

Figure 2.

Detection of early gastric cancers. (a) A well-differentiated adenocarcinoma of the stomach imaged using white light imaging (WLI). (b) A clear line of demarcation is observed using linked color imaging (LCI). (c) An undifferentiated adenocarcinoma of the stomach using WLI. (d) LCI enhances the color contrast between the cancer and the surrounding normal mucosa.

Figure 3.

Detection of colorectal neoplastic lesions. (a) A small polyp in the sigmoid colon seen using white light imaging (WLI). (b) Linked color imaging (LCI) provides clear visualization of the small polyp by enhancing the color contrast. (c) A sessile serrated adenoma/polyp (SSA/P) of the ascending colon seen using WLI. (d) LCI demonstrates a clear line of demarcation by enhancing the color contrast.