Association between white opaque substance under magnifying colonoscopy and lipid droplets in colorectal epithelial neoplasms

AIM To examine the association between white opaque substance(WOS) and histologically verified lipiddroplets in colorectal epithelial neoplasms.METHODS We reviewed colonoscopy records at our institution from 2014 to 2016 and identified cases of endoscopically or surgically resected colorectal epithelial neoplasms observed by magnifying narrow-band imaging(M-NBI) colonoscopy. Immunohistochemistry was used to stain tumors with a monoclonal antibody specific to adipophilin as a marker of lipids. The expression and distribution of adipophilin were compared between WOS-positive and WOS-negative lesions and among tumors classified by histologic type and depth of invasion.RESULTS Under M-NBI colonoscopy, 81 lesions were positive for WOS and 48 lesions were negative for WOS. The rate of adipophilin expression was significantly higher in WOS-positive lesions(95.1%) than in WOS-negative lesions(68.7%)(P = 0.0001). The incidence of deep adipophilin expression was higher in WOS-positive lesions(24.7%) than in WOS-negative lesions(4.2%)(P = 0.001). The incidence of deep expression was predominant among cancers with massive submucosal invasion(62.5%) compared to adenoma(7.2%) and high-grade dysplasia or cancers with slight submucosal invasion(12.7%)(P = 0.0001).CONCLUSION The distribution of lipid droplets may be closely associated with the visibility of WOS under M-NBI colonoscopy, and with histologic grade and depth of tumor invasion.

Magnifying narrow-band imaging endoscopy is superior in diagnosis of early gastric cancer

AIM:To evaluate the diagnostic effectiveness of white light endoscopy,magnifying endoscopy(ME),and magnifying narrow-band imaging endoscopy(ME-NBI) in detecting early gastric cancer(EGC).METHODS:From March 2010 to June 2012,a total of 3616 patients received screening for gastric cancer by magnifying endoscopy. There were 3675 focal gastric lesions detected using conventional high definition white light endoscopy(HD-WLE) in four different referentialhospitals that were recruited for further investigation using ME and ME-NBI. The images obtained from HD-WLE,ME,and ME-NBI were reviewed by four experienced endoscopists to evaluate their diagnostic effectiveness for EGC. The diagnosis of cancerous and non-cancerous lesions was conducted by evaluating the microvascular and microsurface patterns using the VS classification system. The final endoscopic diagnosis of each lesion was determined by consultation when a disagreement occurred. We used histopathological results as the gold standard for the diagnosis of EGC.RESULTS:Among the 3675 lesions found,1508 were validated by pathological findings as chronic gastritis,1279 as chronic gastritis with intestinal metaplasia,631 as low-grade neoplasia,and 257 as EGC. The sensitivity,specificity,positive predictive value,negative predictive value,and accuracy of HD-WLE for the diagnosis of EGC were 71.2%,99.1%,85.5%,97.9% and 97.1%,respectively. The results of ME for diagnosing EGC were 81.3%,98.8%,83.3%,98.6% and 97.6%,respectively. The results of ME-NBI for the diagnosis of EGC were 87.2%,98.6%,82.1%,99.0% and 97.8%,respectively. The diagnostic sensitivity and accuracy of paired ME and ME-NBI were significantly better than those of HD-WLE(P < 0.05).CONCLUSION:HD-WLE has a relatively high accuracy for diagnosing EGC and is an effective screening tool. Further investigations of ME and ME-NBI are required to achieve superior accuracy.

Diagnostic performance of magnifying narrow-band imaging for early gastric cancer: A meta-analysis

AIM: To investigate the performance of magnifying endoscopy with narrow-band imaging(ME-NBI) in the diagnosis of early gastric cancer(EGC).METHODS: Systematic literature searches were conducted until February 2014 in Pub Med, EMBASE, Web of Science, Ovid, Scopus and the Cochrane Library databases by two independent reviewers. Meta-analysis was performed to calculate the pooled sensitivity, specificity and diagnostic odds ratio and to construct a summary receiver operating characteristic(ROC) curve. Subgroup analyses were performed based on the morphology type of lesions, diagnostic standard, the size of lesions, type of assessment, country and sample size to explore possible sources of heterogeneity. A Deeks' asymmetry test was used to evaluate the publication bias.RESULTS: Fourteen studies enrolling 2171 patients were included. The pooled sensitivity, specificity and diagnostic odds ratio for ME-NBI diagnosis of EGC were 0.86(95%CI: 0.83-0.89), 0.96(95%CI: 0.95-0.97) and 102.75(95%CI: 48.14-219.32), respectively, with the area under ROC curve being 0.9623. Among the 14 studies, six also evaluated the diagnostic value of conventional white-light imaging, with a sensitivityof 0.57(95%CI: 0.50-0.64) and a specificity of 0.79(95%CI: 0.76-0.81). When using "VS"(vessel plus surface) ME-NBI diagnostic systems in gastric lesions of depressed macroscopic type, the pooled sensitivity and specificity were 0.64(95%CI: 0.52-0.75) and 0.96(95%CI: 0.95-0.98). For the lesions with a diameter less than 10 mm, the sensitivity and specificity were 0.74(95%CI: 0.65-0.82) and 0.98(95%CI: 0.97-0.98).CONCLUSION: ME-NBI is a promising endoscopic tool in the diagnosis of early gastric cancer and might be helpful in further target biopsy.

Clinical significance of white gastric crypt openings observed via magnifying endoscopy

AIM:To evaluate the relationship between Helicobacter pylori(H.pylori)-induced gastritis and white gastric mucosal crypt openings(COs)in the gastric corpus.METHODS:A total of 175 consecutive patients(including 69 patients with gastric cancer)were enrolled in this study.We used magnifying endoscopy(ME)to observe the mucosa microsurface of the lesser and greater curvature of the gastric corpus(350 areas in all).We focused on areas with a round pit microstructure(primarily observed in non-atrophied areas)and evaluated the white openings of these gastric pits.We classified the whiteness of the COs as the"white-edged dark spot"type(consisting of a dark spot bordered by white);the"white"type(pure white with no dark spot);and the"dense white pit(DWP)"type(dense white,resembling a snowball).Gastritis was also histologically evaluated according to the updated Sydney System.RESULTS:We detected round COs using ME in 246 of the 350 areas examined.The histological examination showed significantly more mononuclear cells and neutrophil infiltration in the"white"and"DWP"types than the"white-edged dark spot"type(P<0.001).Furthermore,significantly high-grade inflammation and evidence of active H.pylori-induced gastritis was observed in the"DWP"type(P<0.001).Significant differences were observed in the whiteness of COs between H.pylori-positive(n=139)and negative(n=36)patients(P<0.001).The sensitivity and specificity of the"white"and"DWP"types for predicting H.pylori infection were78.5%and 81.7%,respectively.Of the patients with gastric cancer,22.5%(18/80)had"white-edged dark spots",51.3%(41/80)had"white"COs,and 26.3%(21/80)had"DWP"-type COs."DWPs"were frequently observed among patients with undifferentiated gastric cancer[45.7%(16/35)].CONCLUSION:CO whiteness detected via ME was associated with histological evidence of gastritis and helps to predict the severity of inflammation and H.pyloriinduced activity.

Standard vs magnifying narrow-band imaging endoscopy for diagnosis of Helicobacter pylori infection and gastric precancerous conditions

BACKGROUND Advances in endoscopic imaging enable the identification of patients at high risk of gastric cancer.However,there are no comparative data on the utility of standard and magnifying narrow-band imaging(M-NBI)endoscopy for diagnosing Helicobacter pylori(H.pylori)infection,gastric atrophy,and intestinal metaplasia.AIM To compare the diagnostic performance of standard and M-NBI endoscopy for H.pylori gastritis and precancerous conditions.METHODS In 254 patients,standard endoscopy findings were classified into mosaic-like appearance(type A),diffuse homogenous redness(type B),and irregular redness with groove(type C).Gastric mucosal patterns visualized by M-NBI were classified as regular round pits with polygonal sulci(type Z-1),more dilated and linear pits without sulci(type Z-2),and loss of gastric pits with coiled vessels(type Z-3).RESULTS The diagnostic accuracy of standard and M-NBI endoscopy for H.pylori gastritis was 93.3%and 96.1%,respectively.Regarding gastric precancerous conditions,the accuracy of standard and M-NBI endoscopy was 72.0%vs 72.6%for moderate to severe atrophy,and 61.7%vs.61.1%for intestinal metaplasia in the corpus,respectively.Compared to type A and Z-1,types B+C and Z-2+Z-3 were significantly associated with moderate to severe atrophy[odds ratio(OR)=5.56 and 8.67]and serum pepsinogen I/II ratio of≤3(OR=4.48 and 5.69).CONCLUSION Close observation of the gastric mucosa by standard and M-NBI endoscopy is useful for the diagnosis of H.pylori gastritis and precancerous conditions.

Narrow-band imaging with magnifying endoscopy for the evaluation of gastrointestinal lesions

Narrow band imaging(NBI) endoscopy is an optical image enhancing technology that allows a detailed inspection of vascular and mucosal patterns, providing the ability to predict histology during real-time endoscopy. By combining NBI with magnification endoscopy(NBI-ME), the accurate assessment of lesions in the gastrointestinal tract can be achieved, as well as the early detection of neoplasia by emphasizing neovascularization. Promising results of the method in the diagnosis of premalignant and malignant lesions of gastrointestinal tract have been reported in clinical studies. The usefulness of NBI-ME as an adjunct to endoscopic therapy in clinical practice, the potential to improve diagnostic accuracy, surveillance strategies and cost-saving strategies based on this method are summarized in this review. Various classification systems of mucosal and vascular patterns used to differentiate preneoplastic and neoplastic lesions have been reviewed. We concluded that the clinical applicability of NBI-ME has increased, but standardization of endoscopic criteria and classification systems, validation in randomized multicenter trials and training programs to improve the diagnostic performance are all needed before the widespread acceptance of the method in routine practice. However, published data regarding the usefulness of NBI endoscopy are relevant in order to recommend the method as a reliable tool in diagnostic and therapy, even for less experienced endoscopists.

Investigation of relationships among gastroesophageal reflux disease subtypes using narrow band imaging magnifying endoscopy

AIM:To investigate the relationships among subtypes of gastroesophageal reflux disease(GERD)using narrow band imaging(NBI)magnifying endoscopy.METHODS:A reflux disease questionnaire was used to screen 120 patients representing the three subtypes of GERD(n=40 for each subtypes):nonerosive reflux disease(NERD),reflux esophagitis(RE)and Barrett’s esophagus(BE).NBI magnifying endoscopic procedure was performed on the patients as well as on 40 healthy controls.The demographic and clinical characteristics,and NBI magnifying endoscopic features,were recorded and compared among the groups.Targeted biopsy and histopathological examination were conducted if there were any abnormalities.SPSS 18.0 software was used for all statistical analysis.RESULTS:Compared with healthy controls,a significantly higher proportion of GERD patients had increased number of intrapapillary capillary loops(IPCLs)(78.3%vs 20%,P<0.05),presence of microerosions(41.7%vs 0%,P<0.05),and a non-round pit pattern below the squamocolumnar junction(88.3%vs 30%,P<0.05).The maximum(228±4.8 vs 144±4.7,P<0.05),minimum(171±3.8 vs 103±4.4,P<0.05),and average(199±3.9 vs 119±3.9,P<0.05)numbers of IPCLs/field were also significantly greater in GERD patients.However,comparison among groups of the three subtypes showed no significant differences or any linear trend,except that microerosions were present in 60%of the RE patients,but in only 35%and 30%of the NERD and BE patients,respectively(P<0.05).CONCLUSION:Patients with GERD,irrespective of subtype,have similar micro changes in the distal esophagus.The three forms of the disease are probably independent of each other.

Clinical relevance of fluorodeoxyglucose positron emission tomography/computed tomography and magnifying endoscopy with narrow band imaging in decision-making regarding the treatment strategy for esophageal squamous cell carcinoma

BACKGROUND Recent advances in endoscopic technology,especially magnifying endoscopy with narrow band imaging(ME-NBI)enable us to detect superficial esophageal squamous cell carcinoma(ESCC),but determining the appropriate method of resection,endoscopic resection(ER)vs surgical resection,is often challenging.Recently,several studies have reported that 18F-fluorodeoxyglucose positron emission tomography(FDG-PET)is a useful indicator for decision-making regarding treatment for superficial ESCC.Although,there are not enough reports on association between FDG-PET uptake and clinicopathological characteristics of superficial ESCC.And,there are not enough reports on evaluating the usefulness of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.This study evaluated clinical relevance of FDG-PET and ME-NBI in decision-making regarding the treatment strategy for ESCC.AIM To investigate the association between FDG uptake and the clinicopathological characteristics of superficial ESCC and its usefulness of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.METHODS A database of all patients with superficial ESCC who had undergone both MENBI and FDG-PET for pre-treatment staging at Aichi Cancer Center Hospital between January 2008 and November 2018 was retrospectively analyzed.FDG uptake was defined positive or negative whether the primary lesion was visualized or could be distinguished from the background,or not.The invasion depth of ESCC was classified according to the Japan Esophageal Society.Primary endpoint is to evaluate the association between FDG uptake and clinicopathological characteristics of superficial ESCC.Secondary endpoint is to investigate the efficacy of combination of FDG-PET and ME-NBI for determining the treatment strategy for superficial ESCC.RESULTS A total of 82 lesions in 82 patients were included.FDG-PET showed positive uptake in 29(35.4%)lesions.Univariate analysis showed that uptake of FDG-PET had significant correlations with circumferential extension(P=0.014),pathological depth of tumor invasion(P<0.001),infiltrative growth pattern(P<0.001),histological grade(P=0.002),vascular invasion(P=0.001),and lymphatic invasion(P<0.001).On multivariate analysis,only depth of tumor invasion was independently correlated with FDG-PET/computed tomography visibility(P=0.018).The sensitivity,specificity,positive predictive value(PPV),negative predictive value(NPV),and accuracy of Type B2 in ME-NBI for the invasion depth of T1a muscularis mucosae and T1b upper submucosal layer were 68.4%/79.4%/50.0%/89.3%/76.8%,respectively,and those of Type B3 for the depth of T1b middle and deeper submucosal layers(SM2 and SM3)were 46.7%/100%/100%/89.3%/90.2%,respectively.On the other hand,those of FDGPET for SM2 and SM3 were 93.3%/77.6%/48.2%/98.1%/80.5%,respectively,whereas,if the combination of positive FDG uptake and type B2 and B3 was defined as an indicator for radical esophagectomy or definitive chemoradiotherapy,the sensitivity,specificity,PPV,NPV,and accuracy were 78.3%/91.5%/78.3%/91.5%/87.8%,respectively.CONCLUSION FDG uptake was correlated with the invasion depth of superficial ESCC.Combined use of FDG-PET and ME-NBI,especially with the microvascular findings of Type B2 and B3,is useful to determine whether ER is indicated for the lesion.

Magnifying endoscopy of gastric epithelial dysplasia based on the morphologic characteristics

AIM:To investigate the difference in magnifying endoscopic findings of gastric epithelial dysplasias(GEDs)according to the morphologic characteristics.METHODS:This study included 46 GED lesions in 45patients who underwent magnifying endoscopy using narrow band imaging(ME-NBI)before endoscopic resection.During ME-NBI,the microvascular and microsurface(MS)patterns and the presence of light blue crest(LBC)and white opaque substance were investigated.GEDs were categorized as adenomatous,foveolar,and hybrid types,and their mucin phenotype was evaluated.RESULTS:Of the 46 lesions,27(59%)were categorized as adenomatous,15(32%)as hybrid,and the remaining 4(9%)as foveolar.All adenomatous GEDs showed the round pit and/or tubular MS patterns,all foveolar GEDs showed the papillary pattern,and hybrid GEDs showed mixed patterns(P<0.001).LBC was more frequently observed in adenomatous GEDs than in hybrid or foveolar GEDs(52%,33%,0%,respectively),although this difference was not significant(P=0.127).The papillary MS pattern was associated with MUC5AC and MUC6 expression,and the round pit and/or tubular MS patterns were associated with CD10expression.CONCLUSION:The MS pattern in ME-NBI findings is useful for predicting the morphologic category and mucin phenotype of GEDs,and ME-NBI findings may guide decisions regarding GED treatment.

Early colon cancer within a diverticulum treated by magnifying chromoendoscopy and laparoscopy

We report a unique case of intramucosal carcinoma in a tubulovillous adenoma arising from a single diverticulum.Endoscopic mucosal resection(EMR)was carried out successfully and completely with the assistance of laparoscopy.A 71-year-old man was admitted to our hospital because of melena and anemia.Emergent colonoscopy showed diverticulosis in the right-sided colon.However,endoscopy could not exactly detect the bleeding site.A flat elevated polyp was found within a single diverticulum located in the descending colon and diagnosed as an intramucosal carcinoma,as magnifying chromoendoscopy revealed a type Ⅳ pit pattern.As his diverticular bleeding repeated,a rightsided hemicolectomy was decided for treatment,the polyp within the diverticulum was also completely removed by EMR with the assistance of laparoscopy.Although a colonic perforation was detected immediately after EMR,the perforation was closed with endoclips intraluminally and also repaired laparoscopically from the serosal side.Histologically,the resected lesion was an intramucosal well-differentiated adenocarcinoma and the surgical margin was free of tumor.

Magnifying chromoendoscopy combined with immunohistochemical staining for early diagnosis of gastric cancer

AIM:To assess the diagnostic value of using magnifying chromoendoscopy combined with immunohisto-chemical staining of proliferating cell nuclear antigen (PCNA)and p53 in the detection of gastric precancerous lesions. METHODS:Ninety-five patients who were treated for abdominal discomfort,abdominal pain,bloating,and acid reflux at our hospital from January 2010 to December 2011 were included in the study.An ordinary gastroscopic procedure was initially performed to select the lesions.All subjects underwent magnifying chromo-endoscopy to observe morphological changes of gastric pits.Biopsies were then taken from each area of interest and sent for pathological examination and detection of PCNA and p53 expression by immunohistochemistry. An immunoreactivity score for each lesion was calcu-lated.Based on immunoreactivity scores,immunohisto-chemical staining was then considered. RESULTS:Compared to intestinal metaplasia,gastric pits were more diverse in size,more irregular in shape, and more disorderly in arrangement in moderate and severe dysplasia.PCNA and p53 expression was sig-nificantly higher in precancerous lesions(intestinal metaplasia and dysplasia)than in chronic gastritis. PCNA expression showed an upward trend in types A-F pits.The number of cases that showed strong PCNA positivity increased significantly with an increase in the severity of lesions.Rank sum test for independent samples showed that p53 expression was significantly higher in types E and F pits than in types A-D pits(H =33.068,P=0.000).Rank sum test for independent samples showed that PCNA expression was significantly higher in types E and F pits than in types A-D pits(H =31.791,P=0.001). CONCLUSION:The presence of types E and F pits,in which p53 and PCNA are highly expressed,is highly sug- gestive of the occurrence of early cancer,and patients developing these changes should be closely followed.

Evolving roles of magnifying endoscopy and endoscopic resection for neoplasia in inflammatory bowel diseases

Magnifying endoscopy is a useful technique to differentiate neoplasia from non-neoplastic lesions. Data regarding the clinical utility of magnifying endoscopy for neoplasia in patients with inflammatory bowel disease(IBD) has been emerging.While Kudo’s pit pattern types Ⅲ-Ⅴ are findings suggestive of neoplasia in non-IBD patients, these pit patterns are predictive of IBD-associated neoplasia as well.However, active chronic inflammatory processes, particularly regenerative changes, can mimic neoplastic pit patterns and may affect a meticulous evaluation of pit pattern diagnosis in patients with IBD. The clinical evidence regarding the utility of magnifying endoscopy with narrow band imaging or endocytoscopy has also been evolving in regard to the diagnosis of IBD-associated neoplasia. These advanced endoscopic techniques are promising for multiple reasons;not only for making an accurate diagnosis of neoplasia, but also in determining if endoscopic resection is appropriate for such lesions in patients with IBD. In this review, we discuss the diagnostic accuracy and limitations of magnifying endoscopy in assessing IBD-associated neoplasia and examine the feasibility and outcomes of endoscopic resection for these lesions.

Brown slits for colorectal adenoma crypts on conventional magnifying endoscopy with narrow band imaging using the X1 system

BACKGROUND Accurate diagnosis of colorectal premalignant polyps,including adenomas,is vital in clinical practice.AIM To investigate the diagnostic yields of novel findings of brown slits for adenomas.METHODS Patients who underwent colonoscopy at the Toyoshima Endoscopy Clinic were enrolled.Polyps sized≥5 mm suspected of adenomas or clinically significant serrated polyps were included in the study.We defined the surface structures of colorectal polyps,which were brown curves inside and along the tubular glands identified using a combination of a new X1 system(Olympus Corporation)and a conventional magnifying colonoscope with non-staining narrow band imaging(NBI),as brown slits.The brown slits corresponded to slit-like lumens on endocytoscopy and histological crypt openings of an adenoma.We evaluated the diagnostic performance of brown slits for adenoma.RESULTS A total of 108 Lesions from 62 patients were eligible.The average age was 60.4 years and 41.9%were male.The mean polyp size was 7.45±2.83 mm.Fifty-seven lesions were positive for brown slits.Histopathological diagnosis comprised 59 low-grade tubular adenomas,16 sessile serrated lesions,and 33 hyperplastic polyps.Among 59 adenomas,56(94.9%)were positive for brown slits.Among 16 sessile serrated lesions,0(0%)was positive for brown slits.Among 33 hyperplastic polyps,1(3.0%)was positive for brown slits.The sensitivity,specificity,and accuracy of brown slits for adenoma were 94.9%,98.0%,and 96.3%,respectively.The positive predictive value and negative predictive value of brown slits for adenoma were also excellent for 98.2%,and 94.1%,respectively.CONCLUSION Brown slits on conventional magnifying endoscopy with non-staining NBI using the X1 system were useful for diagnosing colorectal adenoma.The new endoscopy system could be examined using new standards.

A Strategy for Magnifying Vibration in High-Energy Orbits of a Bistable Oscillator at Low Excitation Levels

This work focuses on how to maintain a high-energy orbit motion of a bistable oscillator when subjected to a low level excitation. An elastic magnifier （EM） positioned between the base and the bistable oscillator is used to magnify the base vibration displacement to significantly enhance the output characteristics of the bistable oscillator. The dimensionless electromechanical equations of the bistable oscillator with an EM are derived, and the effects of the mass and stiffness ratios between the EM and the bistable oscillator on the output displacement are studied. It is shown that the jump phenomenon occurs at a lower excitation level with increasing the mass and stiffness ratios. With the comparison of the displacement trajectories and the phase portraits obtained from experiments, it is vMidated that the bistable oscillator with an EM can effectively oscillate in a high-energy orbit and can generate a superior output vibration at a low excitation level as compared with the bistable oscillator without an EM.

Usefulness of magnifying endoscopy for iodine-unstained lesions in a high-risk esophageal cancer population

AIM: To investigate the usefulness of magnified observations of iodine-unstained esophageal lesions in the histological diagnosis of esophageal mucosa abnormalities, in high-risk esophageal cancer groups. METHODS: The subjects included 38 patients who had at least one of the four criteria known to be highrisk factors for esophageal cancer. Following endoscopic observation, magnified observations were performed on iodine-unstained lesions of the esophagus. The total number of lesions was 43. These lesions were classified as type A (clear papilla), type B (fused papilla), and type C (non-visible papilla) according to the findings. Tissue biopsy was then carried out. Finally the histological findings were graded in terms of histological factors, and their relationships were compared. RESULTS: Of the 43 lesions, 11 were type A, 17 were type B, and 15 were type C under magnifying endoscopy. Histological findings such as inflammatory cell infiltration and basal cell hyperplasia were significantly increased in type B and type C lesions compared with type A lesions (P < 0.05). Low-grade esophageal dysplasia was apparent in 1 (9%) of 11 type A lesions, in 3 (18%) of 17 type B lesions, and in 6 (40%) of 15 type C lesions, with the highest rate in type C. CONCLUSION: Magnified observations of the esophagus, classified by papillary aspects using magnifying endoscopy of iodine-unstained lesions in high-risk esophageal cancer groups, are considered useful in estimating dysplasia and inflammation of esophageal mucosa.

Comparison of white-light endoscopy,optical-enhanced and aceticacid magnifying endoscopy for detecting gastric intestinal metaplasia:A randomized trial

BACKGROUND Gastric intestinal metaplasia(GIM)is a precancerous lesion of the stomach,which severely affects human life and health.Currently,a variety of endoscopic techniques are used to screen/evaluate GIM.Traditional white-light endoscopy(WLE)and acetic-acid chromoendoscopy combined with magnifying endoscopy(MEAAC)are the interventions of choice due to their diagnostic efficacy for GIM.Optical-enhanced magnifying endoscopy(ME-OE)is a new virtual chromoendoscopy technique to identify GIM,which combines bandwidth-limited light and image enhancement processing technology to enhance the detection of mucosal and vascular details.We hypothesized that ME-OE is superior to WLE and MEAAC in the evaluation of GIM.AIM To directly compare the diagnostic value of WLE,ME-AAC,and ME-OE for detection of GIM.METHODS A total of 156 patients were subjected to consecutive upper gastrointestinal endoscopy examinations using WLE,ME-AAC,and ME-OE.Histopathological findings were utilized as the reference standard.Accuracy,sensitivity,specificity,and positive and negative predictive values of the three endoscopy methods in the diagnosis of GIM were evaluated.Moreover,the time to diagnosis with MEAAC and ME-OE was analyzed.Two experts and two non-experts evaluated the GIM images diagnosed using ME-OE,and diagnostic accuracy and intra-and inter-observer agreement were analyzed.RESULTS GIM was detected in 68 of 156 patients(43.6%).The accuracy of ME-OE was highest(91.7%),followed by ME-AAC(86.5%),while that of WLE(51.9%)was lowest.Per-site analysis showed that the overall diagnostic accuracy of ME-OE was higher than that of ME-AAC(P=0.011)and WLE(P<0.001).The average diagnosis time was lower in ME-OE than in ME-AAC(64±7 s vs 151±30 s,P<0.001).Finally,the inter-observer agreement was strong for both experts(k=0.862)and non-experts(k=0.800).The internal consistency was strong for experts(k=0.713,k=0.724)and moderate for non-experts(k=0.667,k=0.598).CONCLUSION For endoscopists,especially experienced endoscopists,ME-OE is an efficient,convenient,and time-saving endoscopic technique that should be used for the diagnosis of GIM.

Magnifying endoscopy for the diagnosis of specialized intestinal metaplasia in short-segment Barrett's esophagus

AIM:To determine whether magnified observation of short-segment Barrett’s esophagus(BE)is useful for the detection of specialized intestinal metaplasia(SIM).METHODS:Thirty patients with suspected short-segment BE underwent magnifying endoscopy up to×80.The magnified images were analyzed with respect to their pit-patterns,which were simultaneously classified into five epithelial types[Ⅰ(small round),Ⅱ(straight),Ⅲ(long oval),Ⅳ(tubular),Ⅴ(villous)]by Endo’s classification.Then,a 0.5%solution of methylene blue(MB)was sprayed over columnar mucosa.The patterns of the magnified image and MB staining were analyzed.Biopsies were obtained from the regions previously observed by magnifying endoscopy and MB chromoendoscopy.RESULTS:Three of five patients with a typeⅤ(villous)epithelial pattern had SIM,whereas 21 patients with a non-typeⅤepithelial patterns did not have SIM.The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of pit-patterns in detecting SIM were 100%,91.3%,92.3%,60%and100%,respectively(P=0.004).Three of the 12 patients with positive MB staining had SIM,whereas 14patients with negative MB staining did not have SIM.The sensitivity,specificity,accuracy,positive predictive value,and negative predictive value of MB staining in detecting SIM were 100%,60.9%,65.4%,25%and100%,respectively(P=0.085).The specificity and accuracy of pit-pattern evaluation were significantly superior compared with MB staining for detecting SIM by comparison with the exact McNemar’s test(P=0.0391).CONCLUSION:The magnified observation of a shortsegment BE according to the mucosal pattern and its classification can be predictive of SIM.

Magnifying endoscopic diagnosis of digestive erosions

Magnifying endoscopy is used to visualize the microstructure and microvascular architecture of gastrointestinal surface mucosa. Microsurface structure of the mucosa includes normal structure,changed structure by inflammation and biological response. Magnifying endoscopy is starting to play an important role in diagnosis of any upper gastrointestinal diseases by assessment of magnified observation. Magnifying endoscopy holds a great deal of promise in the near future because magnifying endoscopic observation is approaching optical biopsy[1].The aim of this review is to describe recent advances in endoscopic technology and to review the available literature pertaining to the clinical application of these techniques in the diagnosis of digestive erosions diseases.

Role of magnifying narrow-band imaging endoscopy for diagnosis of Helicobacter pylori infection and gastric precancerous conditions:Few issues

Standard endoscopy with biopsy and narrow-band imaging with guided biopsy are techniques for the detection of Helicobacter pylori(H.pylori)-related gastritis and precancerous lesions.In this study,the authors compared standard endoscopy and magnified narrow-band imaging(commonly known as NBI-M)in the diagnosis of H.pylori infections,atrophic gastritis,and intestinal metaplasia.Although the sensitivity of NBI-M is better than standard endoscopy,the diagnostic accuracy did not differ substantially between the diagnostic modalities.Future prospective studies may guide endoscopists in difficult cases regarding which modality is more useful and cost-effective for the diagnosis of H.pylorirelated gastritis and precancerous conditions.

Could near focus endoscopy,narrow-band imaging,and acetic acid improve the visualization of microscopic features of stomach mucosa?

BACKGROUND Conventional magnifying endoscopy with narrow-band imaging(NBI)observation of the gastric body mucosa shows dominant patterns in relation to the regular arrangement of collecting venules,subepithelial capillary network,and gastric pits.AIM To evaluate the effectiveness of a new one-dual(near)focus,NBI mode in the assessment of the microscopic features of gastric body mucosa compared to conventional magnification.METHODS During 2021 and 2022,68 patients underwent proximal gastrointestinal endoscopy using magnification endoscopic modalities subsequently applying acetic acid(AA).The GIF-190HQ series NBI system with dual focus capability was used for the investigation of gastric mucosa.At the time of the endoscopy,the gastric body mucosa of all enrolled patients was photographed using the white light endoscopy(WLE),near focus(NF),NF-NBI,AA-NF,and AA-NF-NBI modes.RESULTS The WLE,NF and NF-NBI endoscopic modes for all patients(204 images)were classified in the same order into three groups.Two images from each patient for the AA-NF and AA-NF-NBI endoscopic modes were classified in the same order.According to all three observers who completed the work independently,NF magnification was significantly superior to WLE(P<0.01),and the NF-NBI mode was significantly superior to NF magnification(P<0.01).After applying AA,the three observers confirmed that AA-NF-NBI was significantly superior to AA-NF(P<0.01).Interobserver kappa values for WLE were 0.609,0.704,and 0.598,respectively and were 0.600,0.721,and 0.637,respectively,for NF magnification.For the NF-NBI mode,the values were 0.378,0.471,and 0.553,respectively.For AA-NF,they were 0.453,0.603,and 0.480,respectively,and for AA-NF-NBI,they were 0.643,0.506,and 0.354,respectively.CONCLUSION When investigating gastric mucosa in microscopic detail,NF-NBI was the most powerful endoscopic mode for assessing regular arrangement of collecting venules,subepithelial capillary network,and gastric pits among the five endoscopic modalities investigated in this study.AA-NF-NBI was the most powerful endoscopic mode for analyzing crypt opening and intervening part.