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Introduction: Although endocytoscopy (EC) with narrow-band imaging (NBI) is effective in diagnosing gastric cancer, no diagnostic system has been validated. We explored a specific diagnostic system for gastric cancer using EC with NBI. Methods: Equal numbers of images from cancerous and noncancerous areas (114 images each) were assessed by endoscopists with (development group: 33) and without (validation group: 28) specific training in magnifying endoscopy with NBI. Microvascular and microsurface patterns (MS) in each image were evaluated. Lesions were diagnosed as cancerous when patterns were deemed “irregular.” The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of a diagnosis according to patterns on EC with NBI (microvascular pattern [MV] alone, MS alone, and both) were evaluated and compared between groups to determine the diagnostic performance. Results: In the development and validation groups, diagnoses based on the MV alone had significantly higher accuracy (91.7% vs. 76.3%, p < 0.0001 and 92.5% vs. 67.5%, p < 0.0001, respectively) and sensitivity (88.6% vs. 68.3%, p < 0.0001 and 89.5% vs. 38.6%, p < 0.0001, respectively) than those based on the MS alone. In both groups, there were no significant differences in diagnostic accuracy between using the MV alone and both patterns. Discussion/Conclusion: Evaluation of the MV alone is a simple and accurate diagnostic method for gastric cancer. This system could find widespread applications in clinical practice.

Aims: Evaluating the accuracy of the modified Endoscopic ABC (Endo ABC) classification with an electronic endoscopy with narrow band imaging without magnification in diagnosing Helicobacter pylori (H. pylori)-infected gastritis. Methods: A total of 576 patients were enrolled and they underwent modified Endo ABC. They were stratified into 5 groups (A to E) based on the grades of endoscopic findings. H. pylori-infected gastritis status was determined in the following ways: current H. pylori gastritis was defined as active gastritis and/or chronic atrophic gastritis (CAG) seen on endoscopy and positive H. pylori test, naïve H. pylori gastritis was defined as regular arrangement of collecting venules in the angle of the lesser curvature without CAG and negative H. pylori test, and previous H. pylori gastritis was defined as negative H. pylori tests regardless of the presence of CAG. Results: Endo A has 97% accuracy and 100% positive predictive value in diagnosing naïve H. pylori gastritis. Endo E has 97% accuracy and 100% positive predictive value in diagnosing previous H. pylori gastritis. The accuracy of Endo B and Endo C in diagnosing current H. pylori gastritis was 89 and 82% respectively. Endo D has 87% accuracy in diagnosing previous H. pylori gastritis. Conclusion: This study showed that the modified Endo ABC classification enables to accurately determine the H. pylori-infected gastritis status.

Background/Aims: The aim of the present study was to evaluate the efficacy of magnifying narrow band imaging with acetic acid spray (MA-NBI) in differentiating category 4/5 lesions from category 3 lesions of superficial non-ampullary duodenal epithelial tumors (SNADETs) as per Vienna Classification and to compare the diagnostic performances of both MA-NBI and magnifying narrow band imaging (M-NBI). Methods: We retrospectively identified 60 resected SNADETs (31 category 3 lesions and 29 category 4/5 lesions) in 60 patients who underwent M-NBI and MA-NBI preoperatively. We evaluated vascular and surface patterns using M-NBI and MA-NBI for characterizing category 3 and 4/5 lesions. The surface pattern was classified as tubular, villous, or mix structure using MA-NBI. In addition, lesions with disorganized and unclear structures with irregular margins that can be clearly recognized by MA-NBI were defined as irregular surface structures. Results: For MA-NBI, category 4/5 lesions had a significantly higher mix structure rate and higher irregular surface structure rate than category 3 lesions (62 vs. 16%, p < 0.001, and 86 vs. 19%, p < 0.001, respectively). The diagnostic accuracy of MA-NBI using mix and irregular surface structures for identifying category 4/5 lesions was as follows: sensitivity, 62/86%; specificity, 84/77%; positive predictive value, 78/78%; negative predictive value, 70/86%; and accuracy, 73/82%. The diagnostic accuracy of MA-NBI using irregular surface structure was significantly higher than that of M-NBI (p < 0.05). Conclusion: MA-NBI may be useful in differentiating between category 3 and category 4/5 lesions of SNADETs.

Background: An education system for narrow band imaging (NBI) interpretation requires sufficient exposure to key features. However, access to didactic lectures by experienced teachers is limited in the United States. Aim: To develop and assess the effectiveness of a colorectal lesion identification tutorial. Methods: In the image analysis pretest, subjects including 9 experts and 8 trainees interpreted 50 white light (WL) and 50 NBI images of colorectal lesions. Results were not reviewed with subjects. Trainees then participated in an online tutorial emphasizing NBI interpretation in colorectal lesion analysis. A post-test was administered and diagnostic yields were compared to pre-education diagnostic yields. Results: Under the NBI mode, experts showed higher diagnostic yields (sensitivity 91.5% [87.3–94.4], specificity 90.6% [85.1–94.2], and accuracy 91.1% [88.5–93.7] with substantial interobserver agreement [κ value 0.71]) compared to trainees (sensitivity 89.6% [84.8–93.0], specificity 80.6% [73.5–86.3], and accuracy 86.0% [82.6–89.2], with substantial interobserver agreement [κ value 0.69]). The online tutorial improved the diagnostic yields of trainees to the equivalent level of experts (sensitivity 94.1% [90.0–96.6], specificity 89.0% [83.0–93.2], and accuracy 92.0% [89.3–94.7], p < 0.001 with substantial interobserver agreement [κ value 0.78]). Conclusions: This short, online tutorial improved diagnostic performance and interobserver agreement.

Introduction: Magnifying narrow-band imaging (NBI) is a beneficial modality for the prediction of histology in colonoscopy. The Japan NBI Expert Team (JNET) classification has been established based on the results of online surveys of the diagnostic accuracy of histological features. However, the reliability of the JNET classification has not been examined. The aim of this study was to evaluate the degree of interobserver agreement for JNET classification among endoscopists when evaluating colonic lesions. Methods: We analyzed a total of 246 colonic lesions in this interpretation test. Each lesion image was subsequently reviewed by 3 experienced endoscopists and then classified based on 4 established JNET categories and indeterminate categories between fixed categories. The primary endpoint was the interobserver agreement rate for evaluation of endoscopic findings using the JNET classification. Results: The complete concordance (defined as 3 out of 3 observer agreement) rate was 73% (179/246), while the partial concordance (defined as 2 out of 3 observer agreement) rate was 26% (64/246). Therefore, concordance of at least 2 out of 3 was achieved in 99% of all the lesions and disagreement of the 3 endoscopists was found in only 1% (3/246). Fleiss’s kappa coefficient (κ) was 0.72 for all cases, which represents moderate interobserver agreement for observers. Discussion/Conclusion: Our study highlights the reliability of the JNET classification for colonic neoplastic lesions among experienced endoscopists and demonstrates acceptable interobserver agreement. Further studies validating the clinical applicability of JNET classification are required among endoscopists with a variety of expertise in several clinical settings.

Background: Magnifying endoscopy (ME) with narrow-band imaging (NBI) can visualize a white opaque substance (WOS) in gastric epithelial neoplasms, gastric intestinal metaplasias, and colorectal epithelial neoplasms. Histological examination showed the WOS to be lipid droplets accumulated in the epithelium. The white appearance of colorectal hyperplastic polyps suggests that they may contain WOS, but this has not been investigated as yet. Aims: The purpose of this study was to determine whether WOS is present in colorectal hyperplastic polyps. Methods: We retrospectively evaluated endoscopic images of 26 consecutive lesions investigated by ME with NBI and subsequently endoscopically resected and confirmed to be hyperplastic polyps. Results: WOS was present in 21 of the 26 colorectal hyperplastic polyps (80.8%) based on the findings of ME with NBI. Adipophilin was present in 24 of the 26 colorectal hyperplastic polyps (92.3%). Conclusions: This study is the first to demonstrate that WOS (i.e. lipid droplets) accumulates in the epithelium of colorectal hyperplastic polyps.

Background: The Japan narrow-band imaging Expert Team (JNET) classification of colorectal polyps based on magnifying endoscopy is used in Japan, but not worldwide. The objective of this study was to clarify differences of diagnostic accuracy between JNET users in Japan and non-JNET users in other countries. Methods: A total of 185 colorectal tumors were assessed. Six endoscopists (3 each from Japan and Taiwan) participated in the study. The Japanese endoscopists normally used the JNET classification and the Taiwanese endoscopists normally used the narrow-band imaging International Colorectal Endoscopic classification for diagnosis of colorectal tumors. After receiving a lecture on the JNET classification, they all observed one blue laser imaging magnified image per lesion and performed diagnosis based on the JNET classification. Results: Diagnostic ability was equivalent for Type 1, Type 2A, and Type 2B. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of Type 3 for deep submucosal invasive carcinoma was, respectively, 44.4, 98.3, 57.1, and 97.2% in Group J and 70.0, 94.7, 40.4, and 98.4% in Group T. The PPV for diagnosis of Type 3 with a high confidence was significantly higher in Group J than in Group T (81.8% [55.4–94.6] vs. 44.4% [33.6–50.9], p < 0.05). Conclusions: The PPV for Type 3 differed between the 2 groups, suggesting the need to become familiar with differentiation between Type 2B and Type 3.

Background/Aims: The aim of this study was to evaluate the diagnostic accuracy of magnifying narrow-band imaging (M-NBI) with histopathological confirmation in identifying the demarcation line (DL) of early gastric cancer (EGC). Methods: EGCs resected by endoscopic submucosal dissection after identifying the DL using M-NBI following histopathological confirmation were included. After determining the DL for the entire EGC lesion using M-NBI, at least 4 biopsies were taken from non-cancerous tissues outside the EGC lesion for histopathological confirmation. Results: A total of 330 EGCs were analyzed in this study. The rate of biopsy-negative and negative horizontal margin were 96.7% (319/330) and 97.9% (323/330) in EGC respectively. Tumors larger than 20 mm showed a higher risk for showing remnant cancer cells on biopsies taken outside the DL. Risk factors for a positive horizontal resection margin were tumor size > 20 mm and moderately or poorly differentiated adenocarcinomas. Conclusion: The assessment of demarcation of EGC using M-NBI was excellent in well-differentiated (WD) adenocarcinoma and lesions below 20 mm in size. However, histopathological confirmation is needed to assess the demarcation of non-WD adenocarcinomas and EGC over 20 mm in size.

Background/Aim: The aim of this study was to compare the accuracy of magnifying endoscopy with narrow band imaging for the diagnosis of depth of invasion by Japan Esophageal Society (JES) classification and inter- and intraobserver agreement of JES intrapapillary capillary loop (IPCL) classification. Methods: It was a retrospective observational study that has analyzed 136 patients with esophageal malignant neoplasia with magnifying endoscopy narrow band imaging to compare JES’s IPCL classification to the histopathologic findings and to evaluate the inter- and intraobserver agreement. Results: Histopathologic examinations revealed 34 (25.7%) intraepithelial neoplasias, 70 (51.5%) squamous cell carcinomas (SCCs) in the epithelium or with invasion into the lamina propria mucosa, 21 (15.4%) SCCs with invasion into the muscularis mucosa or mild invasion into the submucosa, and 11 (8.1%) SCCs with moderate or deep invasion into the submucosa. IPCL types B1, B2, and B3 also showed high accuracies of 80.8, 83.1, and 94.1%, respectively. The kappa values for inter- and intraobserver agreements of the IPCL classifications were moderate to almost perfect. Conclusions: In the present study, the JES’s IPCL classification has good accuracy to predict the depth of SCC invasion and moderate to almost perfect intra- and interobserver agreements.

Background/Aims: The diagnostic efficacy of magnifying blue laser imaging (M-BLI) and M-BLI in bright mode (M-BLI-bright) in the identification of early gastric cancer (EGC) was evaluated for comparison to that of magnifying narrow-band imaging (M-NBI). Methods: This prospective, multicenter study evaluated 114 gastric lesions examined using M-BLI, M-BLI-bright, and M-NBI between May 2012 and November 2012; 104 EGCs were evaluated by each modality. The vessel plus surface classification system was used to evaluate the demarcation line (DL), microvascular pattern (MVP), and microsurface pattern (MSP). Results: M-BLI, M-BLI-bright, and M-NBI revealed a DL for 96.1, 98.1, and 98.1% and irregular MVP for 95.1, 95.1, and 96.2% of lesions, respectively, with no significant difference. Irregular MSP was observed by M-BLI, M-BLI-bright, and M-NBI in 97.1, 90.4, and 78.8% of lesions, respectively, with significant differences (p < 0.001). The proportion of moderately differentiated adenocarcinoma with irregular MSP on M-BLI and absent MSP on M-NBI was significantly higher than that with irregular MSP on M-BLI and M-NBI (35.0 and 9.9%, respectively; p = 0.002). Conclusion: M-BLI and M-BLI-bright provided excellent visualization of microstructures and microvessels similar to M-NBI. Irregular MSP in a moderately differentiated adenocarcinoma might be frequently visualized using M-BLI and M-BLI-bright compared with using M-NBI.

Background/Aim: The aim of this study was to examine the relationship between narrow-band imaging (NBI) magnifying observation using the surface pattern as the main evaluation criterion and pit pattern diagnosis on the basis of magnifying observation using a dye in relation to the characteristics of colorectal tumors according to their morphologies. Methods: In this study, NBI observation and pit pattern diagnosis using a dye with magnifying observation were simultaneously performed in our hospital, and the consecutive 786 cases of colorectal lesions (hyperplasia, adenomata and early carcinomas) that had been endoscopically or surgically resected were retrospectively analyzed. NBI magnifying observation was in conformance with the Hiroshima classification and pit pattern diagnosis was in conformance with the Kudo and Tsuruta classification. The relationship between NBI magnifying observation and pit pattern diagnosis and that between NBI magnifying observation and the histological type/invasion depth were examined in relation to colorectal tumor morphology. Results: Type A corresponded to the type II pit pattern, type B corresponded to the type IIIS, type IIIL and type IV regular pit patterns, type C1 corresponded to the type VI slightly irregular pit pattern, type C2 corresponded to the type VI highly irregular pit pattern and type C3 corresponded to the type VN pit pattern. In the protruded type, the irregularity of type C1 or C2 lesions agreed with the type VI slightly or highly irregular pit pattern, respectively, in 114 cases (64.0%). Moreover, the irregularity was higher with NBI magnifying observation than with pit pattern diagnosis in 58 cases (32.6%). In the superficial type, the irregularity of type C1 or C2 lesions agreed with the type VI slightly or highly irregular pit pattern, respectively, in 63 cases (71.6%). Moreover, the irregularity was higher with NBI magnifying observation than with pit pattern diagnosis in 19 cases (21.6%). In the case of type C1 or C2 lesions, the irregularity tended to be higher with NBI magnifying observation than with pit pattern diagnosis in the protruded type compared to the superficial type (p = 0.087). Conclusion: The surface pattern, which was visible in NBI magnifying observation, differed from the pit pattern findings obtained by magnifying endoscopic observation using a dye. Findings were more detailed in pit pattern diagnosis using a dye than in NBI magnifying observation.

Background/Aims: We established a new colorectal T1 invasion depth sub-classification and evaluated it to determine whether total excisional biopsy can be performed on colorectal carcinoma (CRC) cases using narrow-band imaging (NBI) magnification. Methods: The cases included 73 T1 carcinomas selected from 173 early CRC cases. The T1 invasion depth sub-classification was defined as follows: T1a, invasion less than 1,000 μm from the inferior border of the muscularis mucosae; T1b-1, between T1a and T1b-2; and T1b-2, T1b lesions with invasion from the deepest part of the carcinoma to within 1,000 μm of the superior border of the muscularis propria. The T1b-2 lesions were not suitable for total excisional biopsy to be performed on them. We examined the maximum diameter of Type C2 (NBI Hiroshima classification) areas and invasion depth. Results: Among 47 lesions classified as Type C2, 38 lesions showed a maximum diameter of 10 mm or less and were classified as Tis, T1a, or T1b-1. The remaining 9 lesions exceeded 10 mm, and among these, 3 cases were classified as T1b-2 (p = 0.0035). Conclusion: For using the new T1 invasion depth sub-classification to classify T1 CRCs in which total excisional biopsy is possible, it is useful to measure the maximum diameter of the Type C2 area.

Background: Endoscopic submucosal dissection (ESD) has become the standard endoscopic treatment for early gastric cancer without lymph node metastasis. At present, undifferentiated type intramucosal cancers without ulcer findings Method: Forty-six patients who had undergone ESD from July 2002 until July 2010, where the final pathological diagnosis was undifferentiated carcinoma, were assessed for the en-bloc resection ratio, the accuracy rate of depth or extent of diagnosis and survival. Results: In endoscopic ultrasonography studies, the accuracy rate of mucosal lesions was 86%. The rate of en-bloc resection was 91% (42/46) and 5 cases had a positive margin. Four cases had a positive margin in cases of piecemeal resection. Five cases underwent additional surgery, and residual cancer was found in 1 case. There were 2 cases of perforation, 2 of delayed hemorrhage, and no cases of delayed perforation. One case died of multiple liver metastases and 1 died of hepatocellular carcinoma. After a maximum of 8 years, an average of 3.8 years of observation, including 7 cases who had undergone additional surgery, recurrence occurred in only 1 case of liver metastasis. Conclusion: In this study the lesions of undifferentiated adenocarcinoma, which were limited to the mucosa

The narrow-band imaging system can be used to examine the microvascular architecture and surface pattern on the mucosal surface with high sensitivity. The clinical significance of NBI observation is summarized as follows: (1) differential diagnosis of hyperplasia, adenoma, and carcinoma; (2) diagnosis according to the presence of a surface pattern as an alternative to magnifying endoscopic observation with dye spraying, and (3) determination of the invasion depth of an early colorectal carcinoma. However, at present, many NBI magnifying observation classifications for colorectal tumor exist in Japan. To internationally standardize the NBI observation criteria, a simple classification system is required. On the basis of these backgrounds, an international cooperative group (Colon Tumor NBI Interest Group – CTNIG) has developed a simple category classification (NICE classification: NBI International Colorectal Endoscopic Classification) which classifies NBI findings into types 1–3.

Recent studies have suggested that narrow band imaging (NBI) is useful for detecting superficial pharyngeal cancer. Nevertheless, pharyngeal observation is not a routine practice during upper gastrointestinal (GI) endoscopy. Two aims of this study were to evaluate the feasibility of pharyngeal observation during upper GI endoscopy and to determine the prevalence of pharyngeal cancer in asymptomatic high-risk patients.Fifty-year-old or older asymptomatic males with smoking and drinking habits were prospectively recruited as a pharyngeal cancer high-risk group. A total of 224 high-risk patients underwent pharyngeal observation using NBI before conventional upper GI endoscopy. The feasibility of pharyngeal examination without sedation was assessed by a questionnaire for the first 60 participants.The median time for pharyngeal observation was 1.7 min. The questionnaire demonstrated 88% of participants thought the pharyngeal examination acceptable. The NBI examination identified 5 superficial pharyngeal cancers (2 Tis and 3 T1) in 224 high-risk patients; the prevalence of pharyngeal cancer in this group was 2.2%. Three of the 5 patients had a concurrent or past history of esophageal squamous cell carcinoma (ESCC).Pharyngeal observation using NBI during upper GI endoscopy is well tolerated and recommended for all high-risk patients, particularly those with a history of ESCC. Basel.