Role of linked color imaging for upper gastrointestinal disease: present and future

Abstract

Techniques for upper gastrointestinal endoscopy are advancing to facilitate lesion detection and improve prognosis. However, most early tumors in the upper gastrointestinal tract exhibit subtle color changes or morphological features that are difficult to detect using white light imaging. Linked color imaging (LCI) has been developed to overcome these shortcomings; it expands or reduces color information to clarify color differences, thereby facilitating the detection and observation of lesions. This article summarizes the characteristics of LCI and advances in LCI-related research in the upper gastrointestinal tract field.

Keywords: Barrett esophagus; Image enhancement; Linked color imaging; Neoplasms.

Fig. 1.

Fujifilm 700 series endoscope. LCI, linked color imaging; BLI, blue light imaging.

Fig. 2.

Endoscopic findings of gastric tumors using white light imaging (WLI) and linked color imaging (LCI). (A) A IIb+IIc tumor is located at the anterior wall side of the antrum. WLI showed a slightly irregular surface mucosa with the same color as the surrounding mucosa (black arrows). LCI showed an orange-red lesion surrounded by purple mucosa (white arrows). The histologic results revealed a tubular adenoma with high-grade dysplasia. (B) A IIa+IIc tumor located at the postero-lesser curvature side of the lower body was noticed under WLI mode (black arrow). LCI showed an orange lesion, suggestive of cancer, surrounded by pale atrophic mucosa (white arrow). The final histopathological finding is a well-differentiated tubular adenocarcinoma invading the mucosa (lamina propria). (C) WLI shows a slightly irregular lesion on the lesser curvature of the body (black arrow). LCI showed an orange-red lesion partially surrounded by purple mucosa (white arrow). The final histologic result revealed a tubular adenoma with low-grade dysplasia. In all three cases, lesions were distinguished more easily by color contrast in LCI mode than in WLI mode. The mucosal colors in Cases A and C were diffuse redness in WLI and crimson in LCI and those in Case B were orange in WLI and apricot in LCI. Finally, Cases A and C were identified as Helicobacter pylori-positive patients, and Case B was identified as a patient with past infection.

Fig. 3.

Endoscopic findings of Helicobacter-associated gastritis using white light imaging (WLI) and linked color imaging (LCI). (A) Both modes showed mucosal edema, atrophic mucosa, and hemorrhagic spots in the mid to high body of the stomach. Under LCI mode, hemorrhagic spots on the body are more apparent (white arrows). (B) Turbid gastric juices on the gastric fundus were seen in both modes (black arrows). (C) Atrophic change and hemorrhagic spots on the gastric corpus were noticed in both modes. In all three cases, the mucosal color was crimson in LCI mode but slightly red in WLI mode. H. pylori infection was confirmed in all cases.