PROSPECTIVE STUDY OF THE EVALUATION OF THE USEFULNESS OF TUMOR TYPING BY NARROW BAND IMAGING FOR THE DIFFERENTIAL DIAGNOSIS OF GASTRIC ADENOMA AND WELL‐DIFFERENTIATED ADENOCARCINOMA

Background and Aim: Presently, the differential diagnosis of gastric adenoma and well‐differentiated adenocarcinoma by endoscopy is very difficult. We carried out magnifying endoscopy with narrow band imaging (NBI) in lesions that required discrimination between gastric adenoma and well‐differentiated adenocarcinoma, and prospectively evaluated whether the tumor typing that we propose is useful for their differential diagnosis. Methods: The materials were 93 lesions that required differential diagnosis between gastric adenoma and well‐differentiated adenocarcinoma among the gastric epithelial tumors for which endoscopic treatment was planned at three facilities during the 14 months between November 2008 and December 2009. According to the typing method proposed by our facility based on images of the mucosal ultrastructure and microvessels obtained by magnified endoscopy combined with NBI, type I‐II and type III‐V lesions were diagnosed as gastric adenoma and well‐differentiated adenocarcinoma, respectively, before endoscopic treatment, and the accuracy of the diagnoses were prospectively examined by comparing them with the postoperative pathological findings. Results: Of the 93 lesions, 87 could be typed into the five types of our typing method, but six lesions could not be classified. The 87 lesions consisted of 16 type I, 12 type II, 29 type III, 27 type IV, and three type V lesions. The percentages of accurate preoperative diagnoses of types I‐II as adenoma and types III‐V as well‐differentiated adenocarcinoma were 79% and 93%, respectively. Conclusions: The tumor typing based on NBI was useful for the endoscopic differentiation of gastric adenoma and well‐differentiated adenocarcinoma.     

Clinicopathological characteristics of abnormal micro-lesions at the oro-hypopharynx detected by a magnifying narrow band imaging system

Background: Narrow band imaging (NBI) with magnifying endoscopy (NBI‐ME) allows the detection of abnormal micro‐lesions smaller than 5 mm in diameter in the oro‐hypopharynx that could not be visualized previously. The purpose of the present study was to clarify the clinicopathological characteristics of abnormal micro‐lesions of the oro‐hypopharynx detected by NBI‐ME Methods: Of the 62 lesions detected by NBI‐ME, 40 abnormal micro‐lesions in 37 patients were removed by endoscopic treatment and were pathologically evaluated. We reviewed the medical records of patients with these lesions and investigated the relationship between NBI‐ME findings and pathological findings. Results: Pathological examination revealed the following: high‐grade intraepithelial neoplasia (HGIN) in nine (23%) lesions, low‐grade intraepithelial neoplasia (LGIN) in 22 (55%), pharyngitis in seven (18%) and papilloma in two (5%). Two NBI‐ME findings, high microvascular density (MVD) and a brownish area (BA), were recognized more frequently as the grade of malignancy advanced. The likelihood ratio (confidential interval) for having HGIN in the patients with both MVD and BA was 13 (3.62–127). Conclusions: The pathological diagnosis of abnormal micro‐lesions ranged from pharyngitis to HGIN. High MVD and BA may be important findings for grading the malignancy of abnormal micro‐lesions.     

Narrow‐band imaging (NBI) magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team

Many clinical studies on narrow‐band imaging (NBI) magnifying endoscopy classifications advocated so far in Japan (Sano, Hiroshima, Showa, and Jikei classifications) have reported the usefulness of NBI magnifying endoscopy for qualitative and quantitative diagnosis of colorectal lesions. However, discussions at professional meetings have raised issues such as: (i) the presence of multiple terms for the same or similar findings; (ii) the necessity of including surface patterns in magnifying endoscopic classifications; and (iii) differences in the NBI findings in elevated and superficial lesions. To resolve these problems, the Japan NBI Expert Team (JNET) was constituted with the aim of establishing a universal NBI magnifying endoscopic classification for colorectal tumors (JNET classification) in 2011. Consensus was reached on this classification using the modified Delphi method, and this classification was proposed in June 2014. The JNET classification consists of four categories of vessel and surface pattern (i.e. Types 1, 2A, 2B, and 3). Types 1, 2A, 2B, and 3 are correlated with the histopathological findings of hyperplastic polyp/sessile serrated polyp (SSP), low‐grade intramucosal neoplasia, high‐grade intramucosal neoplasia/shallow submucosal invasive cancer, and deep submucosal invasive cancer, respectively.     

Clinicopathological features of narrow‐band imaging endoscopy and immunohistochemistry in ultraminute esophageal squamous neoplasms

To reveal clinicopathological features of narrow‐band imaging (NBI) endoscopy and immunohistochemistry in ultraminute esophageal squamous neoplasms. If a lesion diameter was smaller or same compared with a width of closed biopsy forceps, a lesion was defined to be an ultraminute lesion. Twenty‐five consecutive patients with 33 ultraminute esophageal lesions that were removed by endoscopic mucosal resection were included in the present study. We conducted two questionnaire surveys of six endoscopists by their retrospective review of endoscopic still images. The six endoscopists evaluated the endoscopic findings of the ultraminute lesions on still images taken by conventional white‐light imaging endoscopy and non‐magnified NBI endoscopy in the first questionnaire, and taken by magnified NBI endoscopy in the second questionnaire. An experienced pathologist who was unaware of any endoscopic findings made histological diagnosis and evaluated immunoexpression of p53 and Ki67. The 33 ultraminute lesions were all determined to be either 11 high‐grade intraepithelial neoplasias (HGIENs) or 22 low‐grade intraepithelial neoplasias (LGIENs). The tumor diameters were histologically confirmed to be <3 mm. All of the ultraminute tumors were visualized as unstained areas and brownish areas by real‐time endoscopy with Lugol dye staining and non‐magnified NBI endoscopy, respectively. All of the ultraminute IENs were visualized as brownish areas by real‐time non‐magnified NBI endoscopy. Three of the 25 patients with the ultraminute IENs (12%) had multiple brownish areas (more than several areas) in the esophagus on real‐time non‐magnified NBI endoscopy. All of the ultraminute IENs were visualized as unstained areas by real‐time Lugol chromoendoscopy. Twenty of the 25 patients (80%) had multiple unstained areas (more than several areas) in the esophagus on real‐time Lugol chromoendoscopy. The first questionnaire survey revealed that a significantly higher detection rate of the ultraminute IENs on non‐magnified NBI endoscopy images compared with conventional white‐light imaging endoscopy ones (100% vs. 72%, respectively: P < 0.0001). The second questionnaire survey revealed that presence rates of any magnified NBI endoscopy findings were not significantly different between HGIENs and LGIENs. Proliferation, dilation, and various shapes of intrapapillary capillary loops indicated remarkably high presence rates of more than 90% in both HGIENs and LGIENs. Six of 22 LGIENs (27%) and 3 of 11 HGIENs (27%) show a positive expression for p53. None of peri‐IEN epithelia was positive for p53. A mean of Ki67 labeling index of LGIENs was 33% and that of HGIENs 36%. Ki67 labeling index was significantly greater in the LGIENs and HGIENs compared with that in the peri‐IEN epithelia. There were no significant differences in p53 expression and Ki67 labeling index between the HGIENs and LGIENs. Non‐magnified/magnified NBI endoscopy could facilitate visualization and characterization of ultraminute esophageal squamous IENs. The ultraminute HGIENs and LGIENs might have comparable features of magnified NBI endoscopy and immunohistochemistry.     

DIAGNOSTIC ACCURACY OF PIT PATTERN AND VASCULAR PATTERN ANALYSES IN COLORECTAL LESIONS

Background: The aim of this prospective study is to compare the usefulness of magnifying narrow band imaging (NBI) and magnifying chromoendoscopy in the diagnosis of colorectal lesions. Methods: The subjects were 1185 patients who underwent a complete colonoscopic examination and endoscopic or surgical treatment, from January 2006 to February 2008. A total of 1473 lesions were evaluated (53 hyperplastic polyps, 1317 adenomas, 103 submucosally invasive cancers). The digital images with NBI or chromoendoscopy were recorded and diagnosed independently from each other by two endoscopists who were blinded to the final pathological diagnosis. Results: We could differentiate between neoplastic and non‐neoplastic lesions with sensitivity of 88.9%, specificity of 98.5% and accuracy of 98.2% according to the vascular pattern. By recognizing an irregular or sparse pattern with NBI, massively invasive submucosal cancer could be diagnosed with the sensitivity and specificity of 94.9% and 76.0%. Using chromoendoscopy, we could differentiate between neoplastic and non‐neoplastic lesions with sensitivity of 86.8% and specificity of 99.2%. We were able to differentiate between massively invasive cancers and slightly invasive cancers using the pit patterns with sensitivity of 89.7% and specificity of 88.0%. The specificity was superior to that of NBI colonoscopy. Conclusion: Both NBI and chromoendoscopy can be useful for distinguishing between neoplastic and non‐neoplastic lesions. In the diagnosis of submucosal cancer, pit pattern diagnosis was slightly superior to vascular pattern diagnosis. It is desirable to perform chromoendoscopy in addition to NBI for distinguishing between slightly and massively invasive submucosal cancer lesions and determining the treatment.     

IMPROVEMENT OF CHOLEDOCHOSCOPY: CHROMOENDOCHOLEDOCHOSCOPY,AUTOFLUORESCENCE IMAGING,OR NARROW‐BAND IMAGING

Past and present results concerning assessment of choledochoscopy using chromoendoscopy, autofluorescence imaging (AFI), or narrow‐band imaging (NBI) are summarized herein. On chromoendocholedochoscopy using methylene blue, cancer was stained dark blue. Interestingly, normal bile duct had dimple signs that are a significant feature of non‐neoplastic mucosa. First‐generation AFI (laser‐induced fluorescence endoscopy–gastrointestine system) and system of autofluorescence endoscopy made it possible to detect neoplastic lesions as dark green–black lesions, although the image was insufficient. The sensitivity, specificity and diagnostic accuracy of white light illumination and AFI were 88.0%, 87.5%, 87.7%, and 100%, 52.5%, 70.8%, respectively. In contrast, the recently developed NBI system made it possible to emphasize the imaging of certain features such as mucosal structures and mucosal microvessels. NBI showed not only clear neoplastic findings such as irregular mucosa or tortuous tumor vessel, but also non‐neoplastic findings such as smooth surface mucosa or dimple sign. In conclusion, the diagnostic power of chromoendoscopy and AFI were low, but NBI is expected to become the new‐generation diagnostic tool for biliary tract diseases.     

Usefulness of magnifying endoscopy with narrow-band imaging for determining gastric tumor margin

Background and Aim: Magnifying endoscopy with narrow‐band imaging (ME‐NBI) enhances images of the irregular mucosal structures and microvessels of gastric carcinoma, and could be useful for determining the margin between cancerous and non‐cancerous mucosa. We evaluated the usefulness of ME‐NBI for determining the tumor margin compared with indigocarmine chromoendoscopy (ICC). Methods: The subjects were 110 patients (with 118 lesions) who underwent endoscopic submucosal dissection for gastric tumors. They were randomized into ME‐NBI and ICC groups. Marking was carried out by electrocautery with the tip of a high‐frequency snare at the tumor margins determined by each observation. The distance from the marking dots to the tumor margin was measured histopathologically in the resected specimens. Marking was diagnosed as accurate if the distance was less than 1 mm. Results: Of the 118 gastric lesions, 55 were allocated to the ME‐NBI group, and 63 to the ICC group. Seventeen lesions in the ME‐NBI group and 18 lesions in the ICC group were excluded because the distance from the marking dots to the tumor margin was immeasurable histopathologically. Thirty‐eight lesions in the ME‐NBI group and 45 lesions in the ICC group were evaluated. The rate of accurate marking of the ME‐NBI group was significantly higher than that of the ICC group (97.4% vs 77.8%, respectively; P‐value = 0.009). Conclusion: Magnifying endoscopy with narrow‐band imaging can identify gastric tumor margins more clearly than ICC.     

EVALUATION OF NARROW BAND IMAGING FOR PERORAL CHOLANGIOPANCREATOSCOPY

Used with narrow band imaging (NBI), peroral cholangiopancreatoscopy (PCPS) was performed in eight patients with biliary and pancreatic diseases. The procedures were successfully performed in all patients without any complications after endoscopic sphincterotomy. Direct endoscopic diagnosis within both the bile and pancreatic ducts was well accomplished by the baby scope with NBI. NBI produced higher quality images and was able to show changes of the bile duct wall due to tumor growth. However, bile is seen as red on NBI, so sufficient cleaning of the bile duct is recommended. It is concluded that this procedures is considerably valuable and enables PCPS to easily detect biliary lesions.     

Clinicopathological features of minute pharyngeal lesions diagnosed by narrow-band imaging endoscopy and biopsy

AIM: To evaluate the utility of magnified narrow-band imaging (NBI) endoscopy for diagnosing and treating minute pharyngeal neoplasia.METHODS: Magnified NBI gastrointestinal examinations were performed by the first author. A magnification hood was attached to the tip of the endoscope for quick focusing. Most of the examinations were performed under sedation. Magnified NBI examinations were performed for all of the pharyngeal lesions that had noticeable brownish areas under unmagnified NBI observation, and an intrapapillary capillary loop (IPCL) classification was made. A total of 93 consecutive pharyngeal lesions were diagnosed as IPCL type IV and were suspected to represent dysplasia. Sixty-two lesions of approximately 1 mm in diameter were biopsied in the clinic, and 17 lesions with larger diameters were resected by endoscopic submucosal dissection (ESD) at the Hiroshima University Hospital. In addition to the histological diagnoses, the lesion diameters were microscopically measured in 45 of the 62 biopsies. Thirty-four of the 62 biopsied patients received endoscopic follow up.RESULTS: Minute pharyngeal lesions were diagnosed in 93 of approximately 3000 patients receiving magnified NBI examinations at the clinic. Of the 93 patients with IPCL type IV lesions, 80 were men, and 13 were women. Fifty-six were drinkers, and 57 were smokers. Two had esophageal cancer. Twenty-one lesions were located on the posterior hypopharyngeal wall, and 72 lesions were located on the posterior oropharyngeal wall. All 93 lesions were flat and showed similar findings in the magnified and unmagnified NBI examinations. Although almost all of the IPCL type IV lesions showed faint redness when examined under white light, it was difficult to diagnose the lesions using only this technique because the contrast was weaker than that achieved in the NBI examinations. Of the 93 lesions, only 3 had diameters greater than 2.1 mm. Sixty-two lesions of approximately 1 mm were biopsied in the clinic, whereas 17 larger lesions were treated by ESD at the Hiroshima University Hospital. Of the 79 pharyngeal lesions that were biopsied or resected by ESD, 5 were histologically diagnosed as high-grade dysplasia, 39 were diagnosed as low-grade dysplasia, and 39 were determined to be non-dysplastic lesions. There were no cancerous lesions. Histologically, abnormal cell size variations and increased nuclear size were observed in all of the high-grade dysplasia lesions, while the incidence of these findings in the low-grade dysplasia lesions was low. Of the 62 biopsied lesions, 45 were microscopically measurable. The measured diameters ranged from 0.1 to 2.0 mm. The dysplasia ratios increased with the diameters. A follow-up endoscopic examination of the 34 biopsied patients found the rate of complete resection by biopsy to be 79%. The largest lesion in which complete resection was expected was a low-grade dysplasia of 1.9 mm in diameter.CONCLUSION: Minute pharyngeal lesions suspected to be dysplasia that are identified by NBI magnifying endoscopy should be biopsied to determine the diagnosis and further treatment.     

Diagnosis of undifferentiated type early gastric cancers by magnification endoscopy with narrow-band imaging

Background and Aims: The diagnostic use of magnification endoscopy with narrow‐band imaging (ME‐NBI) to assess histopathologically undifferentiated‐type early gastric cancers (UD‐type EGCs) is not well elucidated. The purpose of this study was to examine the comparative relationship between ME‐NBI images and histopathological findings in UD‐type EGCs. Methods: We analyzed 78 consecutive cases of UD‐type EGCs ≤ 20 mm in diameter that underwent ME‐NBI ≤ 2 weeks prior to resection. The ME‐NBI images were compared with histopathological findings following either endoscopic submucosal dissection (ESD) or surgery. Applying the comparative results, we prospectively evaluated the success of identifying the lateral extent of UD‐type EGCs resected by ESD in additional consecutive cases. Results: Lesions with preserved but irregular surface microstructures (S‐type based on ME‐NBI) showed mucosal atrophy and corresponded histologically to the non‐whole‐layer type of intramucosal cancer (24/24, 100%). Lesions with an irregular microvasculature type (V‐type, for example, corkscrew pattern) or mixed type upon ME‐NBI corresponded histopathologically to the non‐whole‐layer type of intramucosal cancer (15/54, 27.8%), the whole‐layer type of intramucosal cancer (27/54, 50.0%) or submucosal (sm) invasion cancer (12/54, 22.2%). Applying these comparative results, we used ME‐NBI to successfully predict the lateral extent of cancer, which corresponded to the histopathological lateral extent in all 18 additional consecutive UD‐type EGCs resected by ESD. Conclusions: ME‐NBI images of UD‐type EGCs were very closely related to the histopathological findings. Thus, ME‐NBI can be useful in the pretreatment assessment of the histopathological patterns of cancer development and the lateral extent of such lesions.     

Narrow band imaging: Application for early‐stage gastrointestinal neoplasia

Narrow‐band imaging (NBI) is an imaging technique for endoscopy using optical filters to narrow the bandwidth of spectral transmittance. Through this narrow spectrum, NBI contrasts surface structure and microvascular architecture of various lesions. In this article we focus on the application of NBI for early‐stage neoplasia in the esophagus, stomach and colon with a three‐step strategy of endoscopic diagnosis: (i) the detection of abnormality; (ii) the differentiation between non‐neoplasia and neoplasia; and (iii) staging for tumor extension and depth of invasion.     

Significance of each narrow‐band imaging finding in diagnosing squamous mucosal high‐grade neoplasia of the esophagus

Background and Aim: Although narrow‐band imaging (NBI) is used increasingly in clinical situations, the significance of each NBI finding has not been investigated. The primary endpoint of the present study was to identify the significant NBI findings to diagnose esophageal mucosal high‐grade neoplasia. Methods: Between August 2007 and January 2009, we detected 59 new superficial esophageal lesions. The video images of NBI were recorded digitally. NBI findings such as brownish dots (dilated intra‐epithelial papillary capillary loop [IPCL]), tortuous IPCL, elongated IPCL, caliber change in IPCL, variety in IPCL shapes, demarcation line, brownish epithelium, and protrusion or depression were evaluated using the video images. The association between each NBI finding and diagnosis of mucosal high‐grade neoplasia, and intra‐ and interobserver agreement was evaluated. Results: In univariate analysis, brownish epithelium, brownish dots, tortuous IPCL, variety in IPCL shapes and demarcation line were associated significantly with diagnosis of mucosal high‐grade neoplasia. In multivariate analysis, brownish epithelium and brownish dots were confirmed to be independent factors. Odds ratios were 25.5 (95% confidence interval [CI]: 2.4–268) for brownish epithelium and 19.3 (95% CI: 1.8–207.7) for brownish dots. Intraobserver agreement was substantial for brownish epithelium and brownish dots. Interobserver agreement was moderate in brownish epithelium and brownish dots. Conclusions: Brownish epithelium and brownish dots were confirmed to be significant and reproducible NBI findings in the diagnosis of squamous mucosal high‐grade neoplasia of the esophagus. Initial assessment of esophageal lesions should be done based on these findings.     

Meta‐analysis of the effects of endoscopy with narrow band imaging in detecting dysplasia in Barrett's esophagus

Narrow band imaging (NBI) is a real‐time imaging technique. The aim of this meta‐analysis was to estimate the sensitivity, specificity, and diagnostic accuracy on the role of NBI in the detection and characterization of specialized intestinal metaplasia (SIM), high‐grade dysplasia (HGD) in the Barrett's esophagus. We identified studies by performing a literature search of Medline, EMBASE, and the Cochrane Library databases up to May 2013. We performed data analysis using Meta‐DiSc (version 1.4) software. To assess study quality and potential for bias, we used the Quality Assessment of Diagnostic Accuracy Studies‐2 tool (QUADAS‐2). Overall, seven eligible studies including over 3988 lesions of 502 patients were retrieved. The results showed that endoscopic diagnosis of dysplasia performed using NBI has a high diagnostic performance, with an area under the summary receiver operating characteristic (SROC) curve near 0.90 both in HGD lesions and SIM lesions. We also found that NBI has a sensitive and specificity of 0.91 (95% confidence interval [CI] = 0.86–0.94) and 0.85 (95% CI = 0.76–0.92) on a per‐patient element, and 0.97 (95% CI = 0.95–0.98) and 0.64 (95% CI = 0.59–0.68) on a per‐lesion element for SIM diagnosis, respectively. The pooled per‐patient sensitivity and specificity for identifying HGD are 0.91 (95% CI = 0.75–0.98) and 0.95 (95% CI = 0.91–0.97). The pooled per‐lesion sensitivity and specificity for identifying HGD are 0.69 (95% CI = 0.63–0.74) and 0.90 (95% CI = 0.88–0.91). In conclusion, we found that endoscopic diagnosis with NBI is an accurate test to diagnosis dysplasia of Barrett's esophagus.     

Narrow band imaging with magnification for dysplasia detection and pit pattern assessment in ulcerative colitis surveillance: a case with multiple dysplasia associated lesions or masses

A 62 year old man with longstanding ulcerative colitis and previous endoscopic excision of two dysplasia associated lesions or masses (DALMs) was admitted to our endoscopy unit for evaluation and resection of other possible DALMs. He had previously been offered and refused colectomy because of comorbidity from Parkinson's disease. He had multiple polypoid and sessile lesions which were assessed using a third generation prototype narrow band imaging (NBI) colonoscope with magnification. Selected lesions were either biopsied or resected with a combination of endoscopic submucosal dissection and endoscopic mucosal resection techniques. We correlated the pit pattern and vascular pattern intensity seen with magnification NBI with histology of both inflammatory and dysplastic lesions. Dysplastic areas showed Kudo pit patterns II, IIIL, and IV and high vascular pattern intensity. Non-dysplastic and dysplastic areas of recurrence immediately adjacent to the scar from a previous endoscopic mucosal resection site were also assessed. This is the first case report where NBI has been shown to help in DALM detection and to distinguish dysplastic from non-dysplastic mucosa in ulcerative colitis.     

Original article: Prospective evaluation of narrow‐band imaging endoscopy for screening of esophageal squamous mucosal high‐grade neoplasia in experienced and less experienced endoscopists

Narrow‐band imaging (NBI) is a novel, noninvasive optical technique that uses reflected light to visualize the organ surface. However, few prospective studies that examine the efficacy of NBI screening for esophageal cancer have been reported. To compare the diagnostic yield of NBI endoscopy for screening of squamous mucosal high‐grade neoplasia of the esophagus between experienced and less experienced endoscopists. Patients with a history of esophageal neoplasia or head and neck cancer received NBI endoscopic screening for esophageal neoplasia followed by chromoendoscopy using iodine staining. Biopsy specimens were taken from iodine‐unstained lesions and the histological results of mucosal high‐grade neoplasias served as the reference standard. The primary outcome was the sensitivity of NBI for detecting new lesions. The secondary outcome was the positive predictive value of NBI and the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of NBI in a per lesion basis. A total of 350 patients (170 by experienced endoscopists and 180 by less experienced endoscopists) underwent endoscopic examination. A total of 42 new mucosal high‐grade neoplastic lesions (25 in the experienced endoscopist group and 17 in the less experienced endoscopist group) were detected. In the per‐lesion‐based analysis, the sensitivity was significantly higher in the experienced endoscopist group (100%; 25/25) compared with the less experienced endoscopist group (53%; 9/17) (P < 0.001). The positive predictive value of NBI was higher in the experienced endoscopist group than in the less experienced endoscopist group (45%, 25/55 vs. 35%, 9/26), although the difference was not significant (P = 0.50). The sensitivity of NBI in the less experienced endoscopist group was 43% in the former half of patients, and increased to 60% in the latter half of patients. In the per‐patient‐based analysis, the sensitivity of NBI was significantly higher in the experienced endoscopist group (100%) than in the less experienced endoscopist group (100 vs. 69%, respectively; P = 0.04). The positive predictive values of the experienced endoscopist group and the less experienced endoscopist group were similar, and were 48 and 47%, respectively. In conclusion, compared with the gold standard of chromoendoscopy with iodine staining, the sensitivity of NBI for screening of mucosal high‐grade neoplasia was 100% with the experienced endoscopists but was low with the less experienced endoscopists. Electronic chromoendoscopy with NBI is a promising screening tool in these high‐risk patients with esophageal mucosal high‐grade neoplasia, particularly when performed by endoscopists with experience of using NBI.     

PIT PATTERN DIAGNOSIS FOR COLORECTAL NEOPLASIA USING NARROW BAND IMAGING MAGNIFICATION

Narrow band imaging (NBI) is a newly developed technology that uses optical filters for RGB sequential illumination and narrows the bandwidth of spectral transmittance. NBI enables the observation of the fine capillaries in the superficial mucosa of the gastrointestinal tract. In this report, the authors assessed the clinical usefulness of NBI magnification in pit pattern diagnosis for colorectal neoplasia. A total of 90 colorectal lesions including nine cases of hyperplasia, 60 of tubular adenoma and 21 of early carcinoma were analyzed. Histologic diagnosis was undertaken according to World Health Organization classifications. Magnified observation of the lesions was performed using NBI without chromoendoscopy, and pit pattern diagnosis was then recorded. After endoscopic or surgical resection of the lesion, the authors performed stereoscopic examination to confirm the pit pattern. From these data, the authors estimated the ability to diagnose pit patterns using NBI magnification without chromoendoscopy. The correspondence rate of pit pattern diagnosis between NBI magnification without chromoendoscopy and stereoscopic findings was 100% (9/9) for type II, 100% (56/56) for type IIIl , 100% (3/3) for type IV, 80% (12/15) for type Vi , and 57% (4/7) for type Vn . NBI magnification without chromoendoscopy demonstrated good results for pit pattern diagnosis of colorectal neoplasia, especially for lesions with regular pit pattern.     

Utility of narrow band imaging for identification of the orifice of the bile duct during ERCP

Exact identification of the orifice of the bile duct in the major duodenal papilla is required for selective cannulation during endoscopic retrograde cholangiopancreatography (ERCP). However, there are some cases in which the orifice is unclear. The narrow band imaging (NBI) system is an endoscopic imaging technique based on modification of spectral features that enhances visualization of the vascular network. On NBI, bile appears as a bright red fluid, and it is enhanced in the digestive tract. We report two cases in which the NBI was useful for identification of the orifice of the bile duct during ERCP. We recommend the NBI technique before cannulation in cases where the orifice is unclear on the standard image.     

ENDOSCOPIC DIAGNOSIS OF INTRADUCTAL PAPILLARY‐MUCINOUS NEOPLASM OF THE PANCREAS BY MEANS OF PERORAL PANCREATOSCOPY USING A SMALL‐DIAMETER VIDEOSCOPE AND NARROW‐BAND IMAGING

Background: Intraductal papillary‐mucinous neoplasm (IPMN) is an intraductal tumor in which the mucin‐producing epithelium shows proliferated papillary and a wide variety of pathological changes ranging from hyperplasia to adenocarcinoma. Therefore, it is important to determine whether an IPMN is benign or malignant. In the present study of patients with IPMN, the protrusion was observed by a peroral pancreatoscopy (PPS) using a small‐diameter videoscope and narrow‐band imaging (NBI). We carried out the differential diagnosis of benign lesion to malignant lesion. Methods: Between April 2003 and May 2009, PPS using a small‐diameter videoscope by means of NBI was carried out on 21 hospitalized patients with IPMN (10 cases of adenocarcinoma, 11 cases of adenoma or hyperplasia; 14 males and seven females, with a mean age of 69.4 years). Results: Fifteen focal lesions of the 16 cases in the head of the pancreas (93.7%) and four focal lesions of the five cases in the pancreatic body (80%) were observable, whereas two lesions (adenocarcinoma in the pancreatic body, and adenoma in the uncus of pancreas) were not observable. Endoscopically, seven cases were classified as villous type and two cases as vegetative type, and nine cases were diagnosed as adenocarcinoma. Ten cases with sessile type or semipedunculated type were diagnosed as adenoma or hyperplasia. Vascular patterns and protrusions were detected more clearly in the NBI images than under white light observation. Conclusions: When combined with a videoscope and NBI, pancreatoscopy provided a clear image and was useful for evaluating whether the IPMN was benign or malignant.     

Endoscopic video-autofluorescence imaging followed by narrow band imaging for detecting early neoplasia in Barrett's esophagus

BACKGROUND: Video-autofluorescence imaging (AFI) and narrow band imaging (NBI) are new endoscopic techniques that may improve the detection of high-grade intraepithelial neoplasia (HGIN) in Barrett's esophagus (BE). AFI improves the detection of lesions but may give false-positive findings. NBI allows for detailed inspection of the mucosal and (micro)vascular patterns, which are related to HGIN. OBJECTIVE: A proof-of-principle study to combine AFI and NBI to improve the detection of HGIN and to reduce false-positive findings. DESIGN: Cross-sectional study of consecutive eligible patients. SETTING: Single-center. PATIENTS: Twenty patients with BE with suspected or endoscopically treated HGIN were investigated with 2 prototype imaging systems: AFI (inspection with high-resolution videoendoscopy and autofluorescence imaging for detection of lesions) and NBI (for detailed inspection of mucosal and vascular patterns of identified lesions). Lesions were sampled for histopathologic evaluation. MAIN OUTCOME MEASUREMENTS: The positive predictive value of AFI alone and of AFI-NBI for detecting HGIN and the reduction of false-positive findings because of the use of NBI. RESULTS: All of the 28 lesions with HGIN were identified with AFI. Seventeen were identified with white light (61%). Forty-seven suspicious lesions were detected with AFI: 28 contained HGIN (60%) and 19 were false positive (40%). With NBI, 25 of the true-positive lesions had definitely suspicious patterns, and 3 had dubiously suspicious patterns. Of the 19 false positives, 14 were not suspicious on NBI. The false-positive rate, therefore, was reduced from 40% to 10%. Low-grade dysplasia was found in 4 of the remaining 5 false positives. All of the 14 patients with HGIN were identified by AFI-NBI (sensitivity 100%). LIMITATIONS: Uncontrolled study in high-risk patients. CONCLUSIONS: This proof-of-principle study confirms that AFI can be used as a red-flag technique to detect suspicious lesions. With NBI, detailed inspection of the surface patterns can be performed. This combination may increase the accuracy of detecting HGIN in BE.     

MAGNIFYING OBSERVATION OF MICROVASCULAR ARCHITECTURE OF COLORECTAL LESIONS USING A NARROW‐BAND IMAGING SYSTEM

We reviewed the magnifying observation of the microvascular architecture of colorectal lesions and discuss the utility of the detailed observation of the microvascular architecture for differential diagnosis during narrow‐band imaging (NBI) colonoscopy. Angiogenesis is critical to the transition of premalignant lesions in a hyperproliferative state to the malignant phenotype. Therefore, diagnosis based on angiogenic or vascular morphologic changes might be ideal for early detection or diagnosis of neoplasms. In this review, we propose the term ‘meshed capillary’ for the distinction between non‐neoplastic and neoplastic lesions and the capillary classification ‘capillary pattern’ for the differential diagnosis of colorectal lesions. We believe that the combined use of NBI optical chromoendoscopy and real chromoendoscopy decreases the time and cost of screening colonoscopy. To assess the feasibility and efficacy of using the NBI system, further studies are required for colorectal lesions and other lesions of the gastrointestinal tract.