NEWLY DEVELOPED OPTIMAL BAND IMAGING SYSTEM FOR THE DIAGNOSIS OF EARLY GASTRIC CANCER

Background: Magnifying narrow band imaging system is useful for the diagnosis of early gastric cancer. However, it is difficult for the operator of the scope to maintain the correct distance between the tip of the endoscope and the gastric mucosa for appropriate visualization. The newly developed optimal band imaging system can reconstruct good spectral images derived from ordinary endoscopic images and enhance the mucosal surface without magnification as well as with low magnification. This imaging technique is based on narrowing the bandwidth of the conventional image arithmetically, using spectral estimation technology. Methods: We evaluated endoscopic features of 30 lesions with elevated‐type, 32 lesions with depressed‐type and two lesions with flat‐type early gastric cancer using this new system. Results: We found the best images in all cases of early gastric cancers by using a specific combination of the following three wavelengths available in this system: 470 nm for blue, 500 nm for green and 550 nm for red. The optimal band images showed the depressed‐type early gastric cancer as reddish lesions distinct from the surrounding yellowish non‐cancerous area, leading to a clear demarcation line between the cancerous and non‐cancerous mucosa without magnification. Moreover, 30–40‐fold magnified optimal band images showed a clearly irregular microvascular pattern or a microstructure pattern of the mucosal surface in all types of gastric cancers. Conclusion: This new system can provide useful information for diagnosing various types of early gastric cancers without and with low magnification.     

Diagnosis of extent of early gastric cancer using flexible spectral imaging color enhancement

The demarcation line between the cancerous lesion and the surrounding area could be easily recognized with flexible spectral imaging color enhancement (FICE) system compared with conventional white light images. The characteristic f inding of depressed-type early gastric cancer (EGC) in most cases was revealed as reddish lesions distinct from the surrounding yellowish non-cancerous area without magnification. Conventional endoscopic images provide little information regarding depressed lesions located in the tangential line, but FICE produces higher color contrast of such cancers. Histological f indings in depressed area with reddish col- or changes show a high density of glandular structure and an apparently irregular microvessel in intervening parts between crypts, resulting in the higher color con- trast of FICE image between cancer and surrounding area. Some depressed cancers are shown as whitish lesion by conventional endoscopy. FICE also can pro- duce higher color contrast between whitish cancerous lesions and surrounding atrophic mucosa. For nearly flat cancer, FICE can produce an irregular structuralpattern of cancer distinct from that of the surrounding mucosa, leading to a clear demarcation. Most elevated-type EGCs are detected easily as yellowish lesions with clearly contrasting demarcation. In some cases, a partially reddish change is accompanied on the tumor surface similar to depressed type cancer. In addition, the FICE system is quite useful for the detection of minute gastric cancer, even without magnif ication. These new contrasting images with the FICE system may have the potential to increase the rate of detection of gastric cancers and screen for them more effectively as well as to determine the extent of EGC.     

ENDOSCOPIC SUBMUCOSAL DISSECTION FOR EARLY GASTRIC CANCER USING MAGNIFYING ENDOSCOPY WITH A COMBINATION OF NARROW BAND IMAGING AND ACETIC ACID INSTILLATION

Demarcation of early gastric cancers is sometimes unclear. Enhanced‐magnification endoscopy with acetic acid instillation and magnifying endoscopy with a narrow band imaging (NBI) system have been useful for recognition of demarcation of early gastric cancers. We report a patient with early gastric cancer who underwent a successful endoscopic submucosal dissection (ESD) by magnifying endoscopy with the combined use of NBI and acetic acid instillation. A 72‐year‐old man with early gastric cancer underwent ESD. Demarcation of the lesion was not clear, but magnifying endoscopy using the combination of NBI and acetic acid clearly revealed the demarcation. ESD was carried out after spots were marked circumferentially. We identified the positional relation between the demarcation and all markings. Resection of the lesion was on the outside of the markings. Histopathologically, the lesion was diagnosed as a well‐differentiated adenocarcinoma limited to the mucosa. The margins were carcinoma free. Magnifying endoscopy combining the use of NBI with acetic acid instillation is simple and helpful for identifying the demarcation of early gastric cancer. This method may be useful in increasing the rate of complete resection by ESD for early gastric cancer.     

Diagnosis of depressed‐type early gastric cancer using small‐caliber endoscopy with flexible spectral imaging color enhancement

Background and Aim: Small‐caliber endoscopy has lower resolution than normal‐caliber endoscopy, limiting its use in routine outpatient practice. Flexible spectral imaging color enhancement (FICE) strengthens the color contrast of depressed‐type early gastric cancer without magnification. The aim of the present study was to evaluate the detection of depressed‐type early gastric cancer using small‐caliber endoscopy with the FICE system. Methods: Eighty‐two patients diagnosed with depressed‐type early gastric cancer by standard endoscopy and biopsy were evaluated by small‐caliber endoscopy. FICE images and conventional images were compared. Color differences in all 82 lesions were measured between malignant lesions and the surrounding mucosa using the Commission Internationale de L'Eclairage (CIE) 1976 color space. Results: Most cancers were readily detected as reddish lesions on FICE images. Lines of demarcation between the malignant lesion and the surrounding mucosa were easily identified with FICE images, as such cancers could be clearly distinguished from the surrounding atrophic mucosa. Greater median color differences between malignant lesions and the surrounding mucosa were present in FICE images compared with conventional images, resulting in images with better contrast (27.2 vs 18.7, P < 0.0001). Conclusions: Small‐caliber endoscopy with the FICE system provides better color contrast of depressed‐type early gastric cancers than conventional small‐caliber endoscopy, and the FICE system may facilitate the diagnosis of this type of cancer as a new endoscopic modality.     

共聚焦显微内镜对胃凹陷型病变的鉴别诊断价值

目的共聚焦显微内镜（CEM）是将共聚焦显微镜整合于内镜头端的一种新型内镜,可在细胞水平观察活体组织。本研究目的是评价CEM在内镜检查的同时对胃凹陷型病变的病理预测价值。方法应用CEM对43例患者的51个凹陷型病灶进行检查。将CEM诊断与相应部位活检标本的常规病理结果进行前瞻性和双盲对比。结果对每个病灶的边缘和（或）中心的共172个点进行共聚焦扫描,获得4872幅共聚焦图像。CEM可以获得活体的胃黏膜表面和表面下清晰的细胞和胃小凹结构的荧光图像。CEM对胃癌诊断的敏感度、特异度和准确度分别为95．7％、97．6％、97．1％。结论CEM可以在内镜检查的同时对胃癌组织做出准确度很高的虚拟病理学检查,对于胃凹陷型病变的鉴别诊断及胃癌的早期诊断具有较高的应用价值。     

Diagnosis of early gastric cancer using narrow band imaging and acetic acid

AIM: To determine whether the endoscopic findings of depressed-type early gastric cancers(EGCs) could precisely predict the histological type.METHODS: Ninety depressed-type EGCs in 72 patients were macroscopically and histologically identified. We evaluated the microvascular(MV) and mucosal surface(MS) patterns of depressed-type EGCs using magnifying endoscopy(ME) with narrow-band imaging(NBI)(NBI-ME) and ME enhanced by 1.5% acetic acid, respectively. First, depressed-type EGCs were classified according to MV pattern by NBI-ME. Subsequently, EGCs unclassified by MV pattern were classified according to MS pattern by enhanced ME(EME) images obtained from the same angle.RESULTS: We classified the depressed-type EGCs into the following 2 MV patterns using NBI-ME: a fine-network pattern that indicated differentiated adenocarcinoma(25/25, 100%) and a corkscrew pattern that likely indicated undifferentiated adenocarcinoma(18/23, 78.3%). However, 42 of the 90(46.7%) lesions could not be classified into MV patterns by NBI-ME. These unclassified lesions were then evaluated for MS patterns using EME, which classified 33(81.0%) lesions as MS patterns, diagnosed as differentiated adenocarcinoma. As a result, 76 of the 90(84.4%) lesions were matched with histological diagnoses using a combination of NBI-ME and EME.CONCLUSION: A combination of NBI-ME and EME was useful in predicting the histological type of depressedtype EGC.     

Evidence based review of the impact of image enhanced endoscopy in the diagnosis of gastric disorders

Gastric cancer is the third most common cause of cancer-related death.Advanced stages of gastric cancersgenerally have grim prognosis.But,good prognosis can be achieved if such cancers are detected,diagnosed and resected at early stages.However,early gastric cancers and its precursors often produce only subtle mucosal changes and therefore quite commonly remain elusive at the conventional examination with white light endoscopy.Image-enhanced endoscopy makes mucosal lesions more conspicuous and can therefore potentially yield earlier and more accurate diagnoses.Recent years have seen growing work of research in support of various types of image enhanced endoscopy(IEE) techniques(e.g.,dye-chromoendoscopy;magnification endoscopy;narrow-band imaging;flexible spectral imaging color enhancement;and I-SCAN) for a variety of gastric pathologies.In this review,we will examine the evidence for the utilization of various IEE techniques in the diagnosis of gastric disorders.     

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.     

STUDY OF THE TUMOR VESSELS IN DEPRESSED‐TYPE EARLY GASTRIC CANCERS USING NARROW BAND IMAGING MAGNIFYING ENDOSCOPY AND CDNA ARRAY ANALYSIS

Background: Since endoscopic mucosal resection has been applied to differentiated gastric cancers with invasion limited to the mucosal layer, the diagnosis of their differentiation is important. The degree of differentiation varies depending on the size and location of the tumors. Correct diagnosis by biopsy can be difficult because depressed‐type early gastric cancers sometimes contain mixed histology. Methods: Fifteen patients with depressed‐type early gastric cancers were observed by magnifying endoscopy with a narrow band lighting system. The fine mucosal vascular pattern was recorded and compared with the histological differentiation and features of vessels by staining with CD34. In some patients, cDNA array analysis was performed to determine differences among histological types. Results: Tumor vascular patterns were classified into two categories. Grid‐like network patterns not only characterized differentiated type but were also associated with high microvascular density. Short twig‐like patterns typified the undifferentiated type and a low vascular density. Differentiated types highly expressed some angiogenic factors, such as VEGFc and Flt‐4. Conclusions: Tumor vessel pattern of depressed‐type early gastric cancer obtained by narrow band imaging magnifying endoscopy reflects both the histological features and the degree of expression of angiogenic factors.     

内镜窄带成像技术在早期胃癌及异型增生诊断中的应用

目的探讨内镜窄带成像技术（NBI）对早期胃癌及异型增生的诊断价值。方法217例普通胃镜和（或）NBI下表现异常者,依次采用普通放大、NBI结合放大、靛胭脂染色并放大观察,评价各检查方法图像的清晰度,并在NBI模式下于改变最显著部位活检行病理学检查。胃癌和重度异型增生者行内镜超声检查（EUS）,早期胃癌和重度异型增生者行内镜下治疗或手术治疗。结果在观察病变轮廓方面,NBI与染色内镜或普通内镜之间差异均有统计学意义,NBI最清晰,尤其是对于局灶性浅表性病变的观察;对于胃小凹的形态观察,NBI或染色内镜均优于普通内镜;在对胃黏膜微血管的观察中,NBI具有绝对优势。217例中发现轻度异型增生19例,中度异型增生9例,重度异型增生4例,早期胃癌5例。NBI模式下,胃小凹形态分为6种类型,异型增生主要表现为Ⅴ1型及Ⅳ型,早期胃癌主要表现为Ⅵ型。NBI放大内镜下3例早期胃癌可见新生或粗大血管,其中2例观察到螺旋形毛细血管。结论NBI技术操作简便,对胃黏膜病变轮廓显示清晰,放大后更可清晰观察到胃小凹及微血管形态,有助于提高早期胃癌及异型增生的靶向活检准确率。     

Surface pattern classification by enhanced-magnification endoscopy for identifying early gastric cancers

BACKGROUND: The correlation between fine surface patterns of gastric mucosal lesions and early gastric cancer is not sufficiently clear. OBJECTIVE: To evaluate the efficacy of surface pattern classification by enhanced-magnification endoscopy (EME) for identifying early gastric cancers. DESIGN: Observational study. SETTING: All procedures were performed at Mie University Hospital. PATIENTS: A total of 380 consecutive patients who underwent EGD by using magnification endoscopy. Among these subjects were found 250 newly detected lesions suspected of being gastric cancer. METHODS: Conventional magnification endoscopy (CME), magnification chromoendoscopy (MCE), and EME were performed, and surface patterns of lesions were classified into 5 types: type I, small round pits of uniform size and shape; type II, slit-like pits; type III, gyrus and villous patterns; type IV, irregular arrangement and size; and type V, destructive pattern. Biopsy specimens were obtained from all lesions. MAIN OUTCOME MEASUREMENTS: Correlation between surface pattern classification by EME and histopathologic findings of early gastric cancer. RESULTS: Surface patterns were evident by CME/MCE in only 66.4% (166/250) of lesions but in 100% (250/250) of lesions by EME. Classification by EME was as follows: type I, 52 lesions; type II, 12; type III, 146; type IV, 32; and type V, 8. By histopathologic examination, 16 early gastric cancers were detected between type IV or V lesions. Thus, classification of types IV-V strongly correlated with the presence of gastric cancer (sensitivity 100%, specificity 89.7%). LIMITATIONS: Single-center study. CONCLUSIONS: Surface pattern classification by EME may be useful for identifying early gastric cancers.     

MAGNIFICATION ENDOSCOPIC VIEW OF AN EARLY GASTRIC CANCER USING ACETIC ACID AND NARROW‐BAND IMAGING SYSTEM

A 62‐year‐old woman was referred to Mie University Hospital, Tsu, Japan, for examination of upper gastrointestinal tract. The conventional endoscopy showed a slightly depressed lesion on the greater curvature at the gastric body. The surface of surrounding non‐neoplastic mucosa using magnification endoscopy with acetic acid was gyrus‐villous pattern whereas the surface of the lesion was rough. Furthermore, magnification endoscopy using acetic acid and narrow‐band imaging system visualized clearer fine surface pattern of carcinoma. The lesion had a rough mucosa with irregularly arranged small pits. The lesion was resected completely by endoscopic mucosal resection with insulated‐tip electrosurgical knife. Narrow‐band imaging system with acetic acid may be able to visualize not only the capillary pattern but also the fine surface pattern of gastric carcinoma.     

Endoscopic features of early-stage signet-ring-cell carcinoma of the stomach

AIM: To identify the features of early signet ring cell gastric carcinoma using magnification endoscopy with narrow band imaging (NBI).METHODS: A retrospective review was conducted of 12 cases of early signet ring cell gastric carcinoma who underwent treatment in a single institution between January 2009 and April 2013. All patients had magnification endoscopy with NBI and indigo carmine contrast to closely examine the mucosal architecture, including the microvasculature and arrangement of gastric pits. Histologic examination of the final endoscopic submucosal dissection or gastrectomy specimen was performed and compared with the endoscopic findings to identify patterns specific to signet ring cell carcinoma.RESULTS: Twelve patients with early signet ring cell gastric carcinoma were identified; 75% were male, and average age was 61 years. Most of the lesions were stage T1a (83%), while the remainder were T1b (17%). The mean lesion size was 1.4 cm². On standard endoscopy, all 12 patients had a pale, flat lesion without any evidence of mucosal abnormality such as ulceration, elevation, or depression. On magnification endoscopy with NBI, all of the patients had irregularities in the glands and microvasculature consistent with early gastric cancer. In addition, all 12 patients exhibited the “stretch sign”, an elongation or expansion of the architectural structure. Histologic examination of the resected specimens demonstrated an expanded and edematous mucosal layer infiltrated with tumor cells.CONCLUSION: The “stretch sign” appears to be specific for signet ring cell carcinoma and may aid in the early diagnosis and treatment of this aggressive pathology.     

Diagnostic performance of routine esophagogastroduodenoscopy using magnifying endoscope with narrow‐band imaging for gastric cancer

Background and Aim

In Japan, an increase in the number of routine esophagogastroduodenoscopy procedures is expected because several studies have reported that endoscopy screening has reduced gastric cancer mortality. Magnifying narrow‐band imaging has been reported to be effective for accurate diagnosis of gastric abnormalities such as cancers, adenomas, and intestinal metaplasia. However, the efficacy of this method in routine esophagogastroduodenoscopy has not been clarified.

Methods

We divided 3763 patients into two groups. The non‐magnification group included 1842 patients who underwent endoscopy screening using GIF‐H260/LUCERA‐SPECTRUM between October 2014 and February 2015, whereas the magnification group included 1921 patients who underwent screening using GIF‐H290Z/LUCERA‐ELITE between March 2015 and May 2015. In the magnification group, diagnosis of cancer was conducted using the VS classification system. We did not carry out a biopsy when results were confirmed as non‐cancer using magnifying narrow‐band imaging. If cancer was diagnosed, or when a cancer or non‐cancer diagnosis was difficult, we carried out a biopsy. We analyzed and compared the diagnostic performance between the two groups.

Results

Gastric biopsy rate was significantly lower in the magnification group (29%) than in the non‐magnification group (41%) (P < 0.001). Positive predictive value (PPV) for gastric cancer was significantly higher in the magnification group (5.5%) than in the non‐magnification group (2.5%) (P < 0.001). Furthermore, PPV for gastric epithelial neoplasia was significantly higher in the magnification group (7.9%) than in the non‐magnification group (3.2%) (P < 0.001).

Conclusion

Magnifying narrow‐band imaging improves the diagnostic performance of routine esophagogastroduodenoscopy.     

Magnifying endoscopy simple diagnostic algorithm for early gastric cancer (MESDA‐G)

Gastric cancer is the third leading cause of cancer death worldwide. Early detection and accurate diagnosis of mucosal cancer is desirable in order to achieve decreased mortality; cause‐specific survival of patients with early gastric cancer is reported to exceed 95%. Endoscopy is the functional modality to detect early cancer; however, the procedure is not definitive when using conventional white‐light imaging. In contrast, magnifying narrow‐band imaging (M‐NBI), a novel endoscopic technology, is a powerful tool for characterizing gastric mucosal lesions because it can visualize the microvascular architecture and microsurface structure. To date, many reports on the diagnosis of early gastric cancer by M‐NBI, including multicenter prospective randomized studies conducted in Japan, have been published in peer‐reviewed international journals. Based on these published data, we devised a proposal for a diagnostic strategy for gastric mucosal cancer using M‐NBI to simplify the process of diagnosis and improve accuracy. Herein, we recommend a diagnostic algorithm for early gastric cancer using magnifying endoscopy.     

Endoscopic surveillance of gastric cancers after Helicobacter pylori eradication

The incidence and mortality of gastric cancer remains high in East Asian countries. Current data suggest that Helicobacter pylori(H. pylori) eradication might be more effective for preventing gastric cancer in young people before they develop atrophic gastritis and intestinal metaplasia. However, the long-term effect of H. pylori eradication on metachronous cancer prevention after endoscopic resection(ER) of early gastric cancer remains controversial, with some discordance between results published for Japanese and Korean studies.The detection ability of synchronous lesions before ER and eradication of H. pylori directly influences these results. After eradication, some gastric cancers are more difficult to diagnose by endoscopy because of morphologic changes that lead to a flat or depressed appearance. Narrow-band imaging with magnifying endoscopy(NBI-ME) is expected to be useful for identifying metachronous cancers. However, some gastric cancers after eradication show a "gastritislike"appearance under NBI-ME. The gastritis-like appearance correlates with the histological surface differentiation of the cancer tubules and superficial non-neoplastic epithelium atop or interspersed with the cancer. Till date, it remains unclear whether H.pylori eradication could prevent progression of gastric cancer. Until we can establish more useful endoscopic examination methodologies, regular endoscopic surveillance of high-risk groups is expected to be the most beneficial approach for detection.     

窄带成像技术在早期胃癌内镜诊断中的应用

目的探讨窄带成像（NBI）技术对早期胃癌的诊断价值。方法46例常规内镜发现病灶者,分别于放大内镜下行NBI及靛胭脂染色,观察黏膜腺管形态及微血管结构变化,计算清晰度评分;评价病变性质并与术后病理检查结果进行比较。结果NBI与靛胭脂染色腺管结构清晰度评分无显著差异,但微血管结构评分前者明显高于后者,P〈0．05。二者诊断早期胃癌的敏感性、特异性及与病理诊断的符合率无明显差异。结论NBI诊断早期胃癌效果确切,其优点为能清晰显示病灶微血管结构变化,从而提高诊断的精确性。     

Narrow‐band imaging endoscopy with magnification is useful for detecting metachronous superficial pharyngeal cancer in patients with esophageal squamous cell carcinoma

Background and Aims: Head and neck cancers, especially pharyngeal cancers, as well as esophageal cancers frequently coexist either synchronously or metachronously, but most cases of pharyngeal cancer are detected at an advanced stage resulting in poor prognosis. The aim of this study is to evaluate the effectiveness of using narrow‐band imaging (NBI) endoscopy with magnification for early detection of pharyngeal cancer on patients following their treatment for esophageal squamous cell carcinoma (SCC). Methods: This case series was conducted at the National Cancer Center Hospital in Tokyo between April and October 2005 and included 424 consecutive patients for surveillance endoscopy who had previously undergone chemoradiotherapy (CRT) and/or surgery for esophageal SCC. Observation of the pharyngeal region was randomly conducted on 91 patients using NBI endoscopy with magnification (NBI group) and 333 patients using conventional white light endoscopy (control group). Results: The detection rate for pharyngeal cancer was significantly higher using NBI endoscopy with magnification (10.9%; 10/91) compared with conventional endoscopy (1.2%; 4/333) (P < 0.0001). In particular, the detection rate in CRT patients was significantly higher in the NBI group (12.9%; 7/54) than the control group (0.5%; 1/191) (P < 0.0001). In addition, diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the NBI group were 100% (10/10), 97.5% (79/81), 97.8% (89/91), 83.3% (10/12) and 100% (79/79), respectively. Conclusion: NBI endoscopy with magnification is a promising technique for detecting superficial pharyngeal cancer at an early stage in patients previously treated for esophageal SCC.     

Ease of early gastric cancer demarcation recognition: A comparison of four magnifying endoscopy methods

Background and Aim:  Various techniques using magnifying endoscopy (ME) have been developed to enhance images of early gastric cancer (EGC) demarcations, which are often obscure. We investigated four ME methods to determine which is most effective in enhancing the recognition of EGC demarcations: conventional ME (CME), ME with narrow band imaging (NBI-ME), enhanced-magnification endoscopy with acetic acid (EME), and ME with NBI and acetic acid (NBI-EME).
Methods:  Thirty-seven successive patients having a total of 40 EGCs participated in the investigation. The endoscope was fixed and magnification images of EGC demarcations in each patient were recorded using four different ME methods (CME, NBI-ME, EME and NBI-EME). Eight experts and eight non-experts scored each of the four images of each lesion for ease of recognition of demarcation (1 to 4, with 4 being easiest).
Results:  The mean scores of expert and non-expert judges, respectively, for images acquired using each technique were: CME 1.23, 1.24; NBI-ME 2.61, 2.95; EME 2.62, 2.32 and NBI-EME 3.54, 3.50. There were significant differences between the mean scores for the four techniques ( P  < 0.0001) using one-way repeated-measures anova . In a Bonferroni's multiple comparison, the average scores (expert and non-expert) of images acquired using NBI-EME were significantly higher than those acquired using other methods; images acquired by NBI-ME or EME also scored significantly higher than those by CME. Non-experts also scored NBI-ME images significantly higher than CME and EME images.
Conclusions:  Early gastric cancer demarcations were recognized most easily using NBI-EME, and more easily using EME or NBI-ME than CME.     

Efficacy of magnifying chromoendoscopy for the differential diagnosis of colorectal lesions

Magnifying chromoendoscopy is an exciting new tool and offers detailed analysis of the morphological architecture of mucosal crypt orifices. In this review, we principally show the efficacy of magnifying chromoendoscopy for the differential diagnosis of colorectal lesions such as prediction between non‐neoplastic lesions and neoplastic ones, and distinction between endoscopically treatable early invasive cancers and untreatable cancers based on a review of the literature and our experience at two National Cancer Centers in Japan. Overall diagnostic accuracy by conventional view, chromoendoscopy and chromoendoscopy with magnification ranged from 68% to 83%, 82% to 92%, and 80% to 96%, respectively, and diagnostic accuracy of accessing the stage of early colorectal cancer using magnifying colonoscopy was over 85%. Although the reliability depends on the skill in magnifying observation, widespread applications of the magnification technique could influence the indications for biopsy sampling during colonoscopy and the indication for mucosectomy. Moreover, the new detailed images seen with magnifying chromoendoscopy are the beginning of a new period in which new optical developments, such as narrow band imaging system, endocytoscopy system, and laser‐scanning confocal microscopy, will allow a unique look at glandular and cellular structures.