White Light Imaging Endoscopy Research Articles

Flexible transnasal endoscopy with white light or narrow band imaging for the diagnosis of laryngeal malignancy: diagnostic value, observer variability and influence of previous laryngeal surgery

PurposeFlexible transnasal endoscopy is a common examination technique for the evaluation of laryngeal lesions, while the use of narrow band imaging (NBI) has been reported to enhance the diagnostic value of white light endoscopy (WLE). The purpose of this study is to assess observer variability and diagnostic value of both modalities and investigate the possible influence of previous laryngeal surgery on the detection rates of laryngeal malignancy.MethodsThe study was based on the retrospective evaluation of 170 WLE and NBI images of laryngeal lesions by three observers in a random order. The histopathological diagnoses serve as the gold standard.ResultsIn identifying laryngeal malignancy, the sensitivity of NBI proved to be higher than that of WLE (93.3% vs. 77.0%). NBI was also superior to WLE in terms of accuracy (96.3% vs. 92%) and diagnostic odds ratio (501.83 vs. 120.65). Both modalities had a specificity of 97.3%. The inter-observer agreement was substantial (kappa = 0.661) for WLE and almost perfect (kappa = 0.849) for NBI. Both WLE and NBI showed a high level of intra-observer agreement. The sensitivity was significantly lower in images with history of previous laryngeal surgery compared to those without.ConclusionsFlexible transnasal endoscopy has been proved to be a valuable tool in the diagnosis of laryngeal malignancy. The use of NBI can increase the sensitivity and observer reliability in that context and can also provide a diagnostic gain in cases with previous laryngeal surgery

Blue laser imaging with acetic acid enhancement improved the detection rate of gastric intestinal metaplasia.

Our aim was to evaluate the ability of blue laser imaging (BLI) combined with acetic acid (BLI-AA) to detect gastric intestinal metaplasia (GIM). Participants undergoing gastroscopy from July 2017 to February 2018 in our hospital were enrolled prospectively. The abilities of white light imaging endoscopy, BLI endoscopy, and BLI-AA to detect GIM were compared. One hundred six patients undergoing gastroscopy met the inclusion criteria. GIM was diagnosed in 41 patients. For BLI-AA, the sensitivity, specificity, positive predictive, and negative predictive values were 85.4%, 84.6%, 77.8%, and 90.2% respectively. The diagnostic accuracy rate for BLI-AA was 84.9%, which was higher than that of white light imaging endoscopy and BLI endoscopy. For target biopsy, the GIM detection rate for the BLI-AA mode was significantly higher (77.8%, 105/135) than that for the BLI mode (58.3%, 84/144) or the white light endoscopy mode (40.4%, 57/141) (p < 0.05). BLI-AA is an efficient and simple method for the detection of GIM.

Effects of preoperative biopsy on endoscopic submucosal dissection (ESD) for early gastric cancer and intraepithelial neoplasia

Objective To compare the effects of the multi-time patch biopsy under the conventional white light imaging endoscopy (C-WLI) and precise targeted biopsy under magnifying narrow-band imaging endoscopy (M-NBI) on the ESD operation of early gastric cancer and intraepithelial neoplasia. Methods Patients were divided into C-WLI group and M-NBI group, 36 cases in each group. The ESD operations of 2 groups were compared quantitively. Results The mean frequency of selecting biopsy specimen in M-NBI group was (1.45±0.62), significantly lower than that of C-WLI(9.62±2.25) (P 0.05). Whereas submucosal injection time, mucosal dissection time, hemostasis time, wound processing time of M-NBI group were significantly shorter than those of C-WLI group (P<0.01). Conclusion Precise targeted biopsy under M-NBI can obviously shorten the time of the endoscopic submucosal dissection (ESD) operation, with small quantity of biopsy tissues and high positive rate of tissues. Key words: Biopsy; Precancerous lesion; Early gastric cancer; Endoscopic submucosal dissection

Intentional examination of esophagus by narrow-band imaging endoscopy increases detection rate of cervical inlet patch.

Foci of heterotopic gastric mucosa have been identified at different sites in the human body and the most common location is the proximal esophagus which is referred to as cervical inlet patch (CIP). The true prevalence of CIP varies and it is usually incidental findings during endoscopy. Because CIP is always asymptomatic, it was believed to be of little clinical relevance. However, emerging studies have described the acid-secreting characteristics of heterotopic gastric mucosa and associations of CIP with gastroesophageal reflux disease (GERD). In addition, complications such as stricture, fistula, infection, mucosal hyperplasia, and malignant transformation have been reported. In this study, we investigated the prevalence of CIP, its associations with clinical manifestations, and the effect of intentional screening upper esophagus by magnifying endoscopy-narrow-band imaging (ME-NBI) system. Consecutive healthy adults who underwent panendoscopy were separated into two groups. Patients in group I (n = 471) were examined by an endoscopist who intended to find CIPs by ME-NBI. Patients in group II (n = 428) were examined by two endoscopists who were unaware of the study and performed white-light imaging endoscopy. Participants provided questionnaires on GERD-related symptoms. Higher CIP prevalence (11.7% vs. 1.9%, P < 0.0001) and longer duration of esophageal examination (mean ± standard deviation, 17.50 ± 12.40 vs. 15.24 ± 10.78 seconds, P = 0.004) were noted in group I than in group II. Analyzing group I patients revealed the higher prevalences of reflux symptoms (32.7% vs. 18.3%, P = 0.013) and erosive esophagitis (43.6% vs. 25.5%, P = 0.005) in patients with CIP than in those without. CIP was not associated with globus or dysphagia symptoms. More small CIPs (< 5 mm) were detected by ME-NBI than by white-light imaging (85.3% vs. 41.4%, P = 0.001). In conclusion, CIP prevalence was not low under intentional ME-NBI examination of the upper esophagus. The clinical relevance of CIP and its association with GERD require further investigation.

PWE-046 Eye Tracking Assessment Suggests Faster Time To Detection And Greater Attention Span For Dysplastic Lesions With Autofluoresence Compared To White Light Endoscopy

IntroductionSurveillance endoscopy is crucial to the management of Barrett’s oesophagus to diagnose and treat dysplasia. Recent studies have confirmed that increased time of inspection of the Barrett’s mucosa increases detection...

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.

Procedure Time and the Determination of Polypoid Abnormalities with Experience

Procedure length and agreement in detection of abnormalities may limit implementation of chromoendoscopy (CE) for dysplasia surveillance in ulcerative colitis (UC). We investigated these factors among endoscopists inexperienced in this technique. Six investigators performed surveillance colonoscopy with white light endoscopy (WLE) followed by CE on 75 patients with long-standing UC. Interobserver agreement for WLE and CE images of polyps and nonpolypoid mucosa was determined. Withdrawal times from the cecum were compared based on number of colonoscopies performed. Dysplasia detection rate with WLE was compared with CE. The analysis of 586 images (266 WLE and 320 CE) from 57 patients included images of 160 polyps (64 flat) with 29 dysplastic lesions. All investigators identified 10/11 WLE images of dysplasia and 4 identified all 18 CE dysplasia images, 1 missed 1 and 1 missed 3. Four dysplastic lesions were not identified by 1 or more investigators and all measured <5 mm. Interobserver agreement for lesions was high with kappa scores of 0.91 and 0.86 for WLE and CE, respectively. Among the 75 patients enrolled, dysplasia was found in 9.3% with WLE compared with 21.3% with WLE and CE (P = 0.007). Median colonoscopy withdrawal time improved from 31 minutes for endoscopists performing fewer than 5 procedures to 18 minutes for 5 to 14 and 19 minutes for more than 15 procedures. Indigo carmine CE for UC surveillance resulted in high rates of interobserver agreement for polyp detection, acceptable withdrawal times, and enhanced dysplasia detection. These results are encouraging for the implementation of CE programs for chronic UC.

Magnifying endoscopy with narrow-band imaging achieves superior accuracy in the differential diagnosis of superficial gastric lesions identified with white-light endoscopy: a prospective study

Conventional, white-light imaging endoscopy (WLE) results in a significant number of misdiagnoses in early gastric cancer. Magnifying endoscopy combined with narrow-band imaging (ME-NBI) is more accurate in the diagnosis of gastric cancer when the diagnostic triad of the disappearance of fine mucosal structure, microvascular dilation, and heterogeneity is used. The aim of the present study was to evaluate the superiority of ME-NBI in the differential diagnosis of superficial gastric lesions identified with conventional WLE. Prospective, comparative study. Single academic center. This study involved patients who underwent WLE and ME-NBI for surveying synchronous or metachronous cancers because they had a high risk of gastric cancer. Patients with superficial gastric lesions that were diagnosed by WLE as cancer or non-cancer with a slight suspicion of cancer were prospectively enrolled in the study. ME-NBI was used to further characterize lesions picked up with WLE. Sensitivity and specificity for the diagnosis of gastric cancer, with pathology as the criterion standard. A total of 201 lesions (mean diameter [+/- SD] 7.0 +/- 4.0 mm) from 111 patients (98 men, 13 women; mean age 66.3 years) were evaluated. Fourteen of the 201 lesions were pathologically proven as gastric cancer; the others were noncancerous lesions. The sensitivity and specificity for ME-NBI diagnosis with the use of the triad (92.9% and 94.7%, respectively) were significantly better than for WLE (42.9% and 61.0%, respectively; P < .0001). Single center and a highly selected population at high risk for gastric cancer. ME-NBI achieved superior accuracy in the differential diagnosis of superficial gastric lesions identified with WLE. Thus, ME-NBI may increase the diagnostic value of endoscopy in a population at high risk of gastric cancer.

“Eye-tracking” for assessment of image perception in gastrointestinal endoscopy with narrow-band imaging compared with white-light endoscopy

Narrow-band imaging (NBI) is a new imaging methodology for improving the detection rate of gastrointestinal lesions. We aimed to evaluate perception of images by NBI and corresponding standard white-light-endoscopy (WLE) using a computer-guided eye-tracking system. A total of 23 NBI images of various lesions with the 23 corresponding WLE images were assessed in random order by 18 subjects with various endoscopy experience. Before evaluation, a teaching set of three NBI and corresponding WLE images was shown to highlight the characteristics of lesions. An eye-tracking system (Tobii X series with integrated 17-inch monitor) was used to record the eye movements of the subjects while they examined respective images. The following parameters were measured: total time spent on image, time until first fixation of lesion, total number of fixations per image and per lesion, and number of fixations until finding the lesion. In total, 828 experiments were conducted. Lesions could not be detected in 6.5 % (NBI) and 4.1 % (WLE) of images ( P = NS). The total number of fixations and total time spent on respective figures as a whole were significantly greater for NBI images compared with WLE images ( P < 0.003). However, the number of fixations until the lesion was found, the number of fixations on the lesion, and the time until first fixation of the lesion did not differ between the two image groups ( P > 0.1). This is the first study using eye tracking to evaluate image perception in gastrointestinal endoscopy. Significant differences in the interpretation of NBI and WLE images were observed, which may be relevant for the detection and characterization of lesions during endoscopy.

Evaluation of visualization of squamous cell carcinoma of esophagus and pharynx using an autofluorescence imaging videoendoscope system

An autofluorescence imaging (AFI) videoendoscope system produces pseudo-color images combining autofluorescence and green reflectance, with the utility of this system previously confirmed for the diagnosis of bronchial squamous cell carcinoma (SCC). Our aim was to evaluate visualization of esophageal and pharyngeal SCC comparing AFI with white light endoscopy (WLE). Thirty-two patients with superficial esophageal SCC and 11 patients with superficial pharyngeal SCC diagnosed in other hospitals were enrolled in this prospective study. We observed the esophagus and pharynx with WLE followed by AFI and took both WLE and AFI images of the esophageal and pharyngeal SCC. Three experienced endoscopists subsequently evaluated the visualization quality of images from both systems on a three-tier scale: visible, illegible and invisible. A total of 39 superficial esophageal SCC were diagnosed with 20, 11 and eight lesions classified as visible, illegible and invisible, respectively, by WLE compared to 31, three and five lesions, respectively, using AFI. Using AFI, 79% of superficial esophageal SCC lesions were visible, compared to only 51% with WLE (P < 0.05). In addition, 12 superficial pharyngeal SCC were diagnosed with four, five and three lesions considered as visible, illegible and invisible, respectively, using WLE in contrast to nine, three and 0 lesions, respectively, by AFI. Thus, using AFI, 75% of superficial pharyngeal SCC lesions were visible compared with only 33% with WLE (P = 0.13). The AFI system appears to be more useful than WLE for early diagnosis of SCC of the esophagus and pharynx.

Magnifying endoscopy combined with narrow-band imaging for differential diagnosis of superficial depressed gastric lesions

Magnifying endoscopy combined with narrow-band imaging (ME-NBI) has been used for differential diagnosis of various focal lesions. The aim of our study was to evaluate ME-NBI criteria for cancer diagnosis in superficial depressed gastric lesions in comparison to conventional white light endoscopy (WLE). ME-NBI and WLE images of 100 superficial gastric depressions (55 depressed cancers, 45 benign depressions) were independently evaluated by 11 endoscopists blinded to the diagnosis in each case. The presence or absence of predefined ME-NBI findings relating to microvasculature and fine mucosal structure (FMS) was recorded. A general diagnosis of benign or malignant also had to be given on the basis of a general assessment of features of color and shape as shown in the ME-NBI and WLE images, respectively, without regard to any prespecified criteria. Multivariate and ROC analysis demonstrated that the triad of FMS disappearance, microvascular dilation, and heterogeneity appeared to be the best combination for diagnosis of gastric cancer. ME-NBI diagnosis with the triad attained a good specificity (85 %, theoretically calculated if all of the triad were positive), which was significantly ( P < 0.001) superior to WLE general diagnosis (65 %), and comparable with ME-NBI general diagnosis (80 %). The sensitivities of the three diagnoses (ME-NBI with the triad 69 %, WLE general diagnosis 71 %, ME-NBI general diagnosis 72 %) were comparably moderate. The kappa values (interobserver concordance) for ME-NBI diagnosis with the triad (0.47) and ME-NBI general diagnosis (0.48) were superior to the kappa value for WLE diagnosis (0.34). The triad of FMS disappearance, microvascular dilation, and heterogeneity has good specificity for the diagnosis of superficial depressed gastric carcinoma, but the sensitivity needs to be improved.

Chromoendoscopy and Narrow-Band Imaging Compared With High-Resolution Magnification Endoscopy in Barrett’s Esophagus

The aim of this study was to compare magnified still images obtained with high-resolution white light endoscopy, indigo carmine chromoendoscopy, acetic acid chromoendoscopy, and narrow-band imaging to determine the best technique for use in Barrett's esophagus. We obtained magnified images from 22 areas with the 4 aforementioned techniques. Seven endoscopists with no specific expertise in Barrett's esophagus or advanced imaging techniques and 5 international experts in this field evaluated these 22 areas for overall image quality, mucosal image quality, and vascular image quality. In addition, the regularity of mucosal and vascular patterns and the presence of abnormal blood vessels were evaluated, and this was correlated with histology. The interobserver agreement for the 3 features of mucosal morphology with white light images ranged from kappa = 0.51 (95% confidence interval [CI]: 0.46-0.55) to kappa = 0.53 (95% CI: 0.50-0.57) for all observers, from kappa = 0.43 (95% CI: 0.33-0.54) to kappa = 0.53 (95% CI: 0.41-0.64) for experts, and from kappa = 0.51 (95% CI: 0.15-0.33) to kappa = 0.64 (95% CI: 0.58-0.70) for nonexperts. The interobserver agreement in these groups did not improve by adding one of the enhancement techniques. The yield for identifying early neoplasia with white light images was 86% for all observers, 90% for experts, and 84% for nonexperts. The addition of enhancement techniques did not improve the yield neoplasia. The addition of indigo carmine chromoendoscopy, acetic acid chromoendoscopy, or narrow-band imaging to white light images did not improve interobserver agreement or yield identifying early neoplasia in Barrett's esophagus.