Usefulness of Magnifying Narrow-Band Imaging Endoscopy for the Diagnosis of Gastric and Colorectal Lesions

Abstract

A series of studies about the potential usefulness of magnifying endoscopy with narrow-band imaging (NBI) for the diagnosis of gastric and colonic lesion is reviewed. Concerning the magnifying NBI appearances of gastric lesions, a light blue crest is a highly accurate sign of the presence of histological intestinal metaplasia. Also, the degree of irregularity of the mucosal and vascular pattern is correlated with the histological severity of Helicobacter pylori-associated chronic gastritis. According to the ‘VS classification’, an irregular microvascular pattern and/or an irregular microsurface pattern together with a clear demarcation line are characteristic for early gastric carcinoma, and a multicenter prospective randomized controlled trial demonstrated that magnifying endoscopy with NBI is superior to ordinary white light endoscopy for making a differential diagnosis of a small depressed lesion between carcinoma and non-carcinoma. Concerning the magnifying NBI appearances of colonic tumor, the vague or invisible microvascular pattern is mostly observed in hyperplastic polyp. The regular meshed microvascular pattern is mostly observed in adenoma. The irregular meshed microvascular pattern is mostly observed in intramucosal or shallow submucosal-invasive carcinoma. The decreased or loose microvasucular pattern is mostly observed in deep submucosal-invasive carcinoma. Thus, magnifying NBI endoscopy is useful for the differentiation of colorectal non-adenomatous lesions from adenoma, the differentiation of adenoma from carcinoma, and the assessment of invasion depth of early colorectal carcinoma. At present, several magnifying NBI classifications for the diagnosis of early colorectal neoplasia have been proposed in Japan. Recently, the NICE classification based on NBI findings with/without magnification for colorectal tumor was established by an international group.

Narrow band imaging-assisted transurethral resection reduces the recurrence risk of non-muscle invasive bladder cancer: A systematic review and meta-analysis

“…The last trials showed that the recurrence rates increased from 4% at 3 mo to 32% at 1 yr for NBI-TUR and from 12% to 51% for WLI-TUR. Because of the increasing trend of tumor recurrence, some recurrence is attributed to causes other than missed tumors, such as the field cancerization effect [35] or the clonal origin of urothelial cancer [13], which are not yet completely understood. The recurrence mechanism of NMIBC should be further studied.…”

“…NBI improves tumor visibility by enhancing the contrast between vascularized lesions and normal mucosal [10–12]. These features allow NBI to detect small or flat early tumors that are difficult to observe by WLI [13]. Systems integrating both NBI and WLI are already available.…”

Advantage of transurethral resection with narrow band imaging for non-muscle invasive bladder cancer

“…Thus, the contrast between urothelial carcinomas (UCs) and normal urothelium is enhanced by NBI, allowing for the detection of UCs more easily. This feature is particularly noticeable for small or flat early UCs, which conventional WLI struggles to detect (2).…”

Usefulness of magnifying endoscopy with narrow-band imaging for diagnosis of depressed gastric lesions

“…Magnifying endoscopy combined with narrow band imaging (ME-NBI) enables a clear visualization of the microvascular architecture and the microsurface structure of the superficial section of the mucosa. Certain studies have demonstrated that ME-NBI findings are closely associated with the histological type of gastric mucosal lesion (2,(6)(7)(8)(9). In particular, irregularities of microstructures have been revealed to be crucial for the endoscopic diagnosis of early gastric cancer (10)(11)(12)(13)(14).…”