Diffuse redness in linked color imaging is useful for diagnosing current Helicobacter pylori infection in the stomach.

Esophagogastroduodenoscopic examination shows diffuse redness of the mucosa of the gastric body, which can be identified as a deep reddish color. The present case underscores the importance of diffuse redness as a key endoscopic feature that enables prompt diagnosis of current Helicobacter pylori infection.

A 67‐year‐old Japanese man was diagnosed with gastritis following a barium swallow examination, which was performed as an annual screening procedure. He was referred to our hospital for further investigation. Serological testing revealed a negative Helicobacter pylori antibody. Esophagogastroduodenoscopic examination (EG‐L600ZW; FUJIFILM Medical Co., Ltd., Tokyo, Japan) revealed atrophic gastritis and intestinal metaplasia. Endoscopic examination performed using linked color imaging showed diffuse mucosal redness in the gastric body, which appeared as a deep red (crimson) mucosa in the area of the fundic glands (Figure 1A). Linked color imaging also showed obvious differences in the mucosal color between areas with diffuse redness (areas with active gastritis) and those that appeared clear white (areas with mucosal atrophy) (Figure 1B). The diffuse redness of the gastric body mucosa was less evident using conventional white light imaging (Figure 2). Spotty redness, mucosal swelling, regular arrangement of collecting venules in the angle, and fundic gland polyps were absent. Based on the presence of the diffuse redness, we performed a urea breath test, which was observed to be positive for H. pylori infection. Thus, subsequently, the patient underwent H. pylori eradication therapy.

Figure 1

Endoscopic images using linked color imaging. Esophagogastroduodenoscopic examination shows diffuse redness of the mucosa of the gastric body, which can be identified as a deep reddish color (A). An obvious difference can be observed in the mucosal color between areas with diffuse redness (B, dagger) and areas showing mucosal atrophy (B, asterisks)

Figure 2

Endoscopic images using conventional white light imaging. Diffuse redness of the mucosa of the gastric body is less evident compared with linked color imaging

In this patient, despite the negative serological test for H. pylori antibody, the findings of an endoscopic examination using linked color imaging prompted us to perform the urea breath test. Eventually, we could prove the presence of current H. pylori infection in this patient. Sensitivity of the serum H. pylori antibody test is reportedly 78%‐100%.1 Thus, this patient showed a false‐negative result to serum antibody testing. In such patients, endoscopic examination plays an important role in identifying current H. pylori infection, that is, active gastritis. Several researchers have stated that diffuse redness is the most important endoscopic finding associated with active gastritis.2, 3 The sensitivity of diffuse redness for diagnosing H. pylori infection is reportedly 83.4%, specificity is 66.9%, positive predictive value is 73.8%, and negative predictive value is 78.4%.2 Other findings associated with active H. pylori infection include spotty redness and mucosal swelling. However, as spotty redness and mucosal swelling were absent in the presented patient, diffuse redness was the sole key feature.

Linked color imaging is a technology that processes the captured image to provide images with color enhancement of reddish hues, such that red areas appear vivid red and white areas appear clear white.4 Reportedly, using linked color imaging, the fundic gland mucosa shows diffuse redness (deep crimson red) in patients with active gastritis and appears light orange in color (the color of white apricots) in the H. pylori‐eradicated stomach.3 Thus, linked color imaging technology is expected to provide useful information to endoscopists to promptly diagnose the H. pylori infection status of the stomach.

In conclusion, the present case underscores the importance of diffuse redness as a key endoscopic feature that enables prompt diagnosis of current H. pylori infection. Notably, the novel linked color imaging technique probably scores over conventional ones in detecting diffuse redness.

CONFLICT OF INTEREST

The authors have stated explicitly that there are no conflicts of interest in connection with this article.