Narrow-band Imaging Colonoscopy Research Articles

Narrow-band imaging endoscopy in differential diagnosis of colorectal proliferative lesions

Objective To evaluate the narrow-band imaging （NBI） in differential diagnosis of colorectal proliferative lesions. Methods Suspected lesions in colon were examined with white light and NBI colonoscopy, respectively. The ensitivity and specificity in diagnosing colorectal inflammatory hyperplasia, adenoma, early cancer and advanced cancer were compared between NBI and conventional colonoscopy with reference to pathology as gold standard. The pit patterns and the surface microvessels of the lesions were also determined and scored with NBI combined with magnifying endoscopy, and were compared with pathological diagnosis. Results （ 1 ） A total of 368 lesions were detected in 280 patients with conventional colonoscopy and NBI. The sensitivity and specificity of NBI in differential diagnosis of colorectal lesions were superior to those of conventional colonoscopy. （2） The pit patterns of colorectal inflammatory hyperplasia were mainly type Ⅰ and Ⅱ , while in adenomas were mainly type Ⅱ and Ⅲ （94. 2% ）. The pit patterns of early cancer were type Ⅲ （ 18.8% ）, Ⅳ （56. 3% ） and V （25.0%）, and those of advanced cancer were mainly typeⅤ （94. 0% ）. （ 3 ） The average scores of surface microvessels of colorectal inflammatory hyperplasia, adenoma, early cancer and advanced cancer were 1.35 ± 0. 72, 3.86 ± 1.07, 6. 52 ± 2.59 and 11.42 ± 3.59, respectively. Scores over 6. 5 was a strong indicator of malignant lesions. Conclusion NBI is superior to conventional eolonoseopy in differential diagnosis of colorectal lesions. Observing pit patterns and microves-sels of the lesion with combination of NBI and magnifying endoscopy is helpful in diagnosis. Key words: Colonscopy ; Narrow-band imaging; lntestimal Neoplasms ; Microvessel

Narrow-Band Imaging in diagnosis of colorectal neoplasm

Objective To evaluate the efficacy of narrow-band imaging （NBI） in diagnosis of colorectal neoplasm. Methods A total of 96 eolorectal neoplasm from 78 patients were observed under NBI, and the findings were compared with those from magnifying chromo-endoscopy and pathologic examinations. Resuits The sensitivity of conventional colonoscopy in diagnosis of polyps was 78. 7% , which was increased to 99% （ P 〈 0. 05 ） under NBI, with the clear identification of the shape and boundary of the lesions. Magnifying NBI colonoscopy provided images of pit patterns similar to those from chromo-endoscopy in diagnosis of type Ⅱ , ⅢL, Ⅳ andⅤN, which showed better recognition than conventional colonoscopy, but less sensitivity than chromo-endoscopy. Superficial vascular morphologic features could be better classified with NBI, with sensitivity of 100% and specificity at 87. 8%, which was superior to conventional colonoscopy but inferior to chromo-endoscopy. Conclusion Both chromo-endoscopy and NBI colonoscopy have better sensitivity and specificity in detection of colon polyps, while chromo-endoscopy reveals clear superficial structure of lesion and pit pattern, and NBI demenstrates capillary morphology, which can distinguish neoplasm from nonneoplasm colorectal lesions. NBI, easy and convenient to switch, is an effective technique to make early diagnosis of colorectal neoplasm. Key words: Colonic neoplasm ; Endoscopy ; Narrow-band imaging; Chromo-endoscopy

Chromoendoscopy, Narrow-Band Imaging Colonoscopy, and Autofluorescence Colonoscopy for Detection of Diminutive Colorectal Neoplasia in Familial Adenomatous Polyposis

This study was designed to compare the diagnostic yield of white light colonoscopy, chromoendoscopy, narrow-band imaging, and autofluorescence imaging in the detection of diminutive lesions. Thirteen patients with adenomatous polyposis were examined by total colonoscopy using an instrument that incorporated both narrow-band and autofluorescence imaging. Colonoscopic images were obtained using white light colonoscopy, autofluorescence imaging, narrow-band imaging, and chromoendoscopy. All images were captured at equivalent angles and distances from the colorectal mucosa. Chromoendoscopy detected the greatest number of lesions at all sites within the large intestine, and it detected a significantly greater number than the other procedures on the left side of the large intestine. Narrow-band imaging depicted a greater number of lesions than did white light in the transverse colon, descending colon, and rectum. Autofluorescence imaging showed a greater number of lesions than did white light in the rectum. The total number of depicted lesions under chromoendoscopy (43.3 +/- 38.5) was significantly greater than the total number detected with white light (12.2 +/- 13.9, P = 0.005), autofluorescence imaging (21.4 +/- 27.5, P = 0.0006), and narrow-band imaging (20.1 +/- 21.5, P = 0.003). Narrow-band imaging detected a significantly higher total number of lesions than did white light (P = 0.04). Chromoendoscopy is superior to white light colonoscopy, autofluorescence imaging, and narrow-band imaging for detection of diminutive colorectal lesions in adenomatous polyposis.

W1075 Angiogenesis of Colorectal Lesions Observed By Narrow Band Imaging Colonoscopy

W1075 Angiogenesis of Colorectal Lesions Observed By Narrow Band Imaging Colonoscopy

Chromocolonoscopy detects more adenomas than white light colonoscopy or narrow band imaging colonoscopy in hereditary nonpolyposis colorectal cancer screening

Individuals carrying germline mutations in one of the genes responsible for hereditary nonpolyposis colon cancer (HNPCC) have a lifetime risk of up to 80 % of developing colorectal cancer. As there is evidence for a higher incidence of flat adenomatous precursors and because an accelerated adenoma-carcinoma sequence has been postulated for these patients, early detection of these lesions is essential. It was the aim of the present study to assess the detection rate of polypoid lesions by comparing chromocolonoscopy with standard white light colonoscopy and narrow-band imaging (NBI) colonoscopy. 109 patients were included (98 with a functionally relevant mutation in a mismatch repair gene, 11 fulfilling the strict Amsterdam criteria). In 47 patients, standard colonoscopy was followed by chromocolonoscopy with indigo carmine. In 62 patients, NBI was performed first followed by chromocolonoscopy. A total of 128 hyperplastic and 52 adenomatous lesions were detected. In the first series, 0.5 lesions/patient were identified by standard colonoscopy and 1.5 lesions/patient by chromocolonoscopy ( P < 0.001). In the second series, 0.7 lesions/patient were detected by NBI colonoscopy and 1.8 lesions/patient by chromocolonoscopy ( P = 0.01). At least one adenoma was detected in 15 % of patients by both standard and NBI colonoscopy compared with 28 % of patients by chromocolonoscopy. According to this study, chromocolonoscopy detects significantly more hyperplastic and, in particular, adenomatous lesions than standard white light colonoscopy or NBI.

Narrow-band imaging for improving colorectal adenoma detection: appropriate system function settings are required

We read with considerable interest the report by Alder et al ( Gut 2008; 57 :59–64) concerning their prospective randomised study on narrow-band imaging (NBI) versus conventional high-resolution imaging for...

Mucosal vascular pattern in ulcerative colitis: observations using narrow band imaging colonoscopy with special reference to histologic inflammation

Narrow band imaging (NBI) is a novel endoscopy system, which enables a clear visualization of the mucosal vasculature of the gastrointestinal tract. The aim of this study is to determine whether this system may be of value for assessing the disease severity in ulcerative colitis (UC). We observed the mucosal vascular pattern (MVP) in 157 colorectal segments of 30 patients with UC using both conventional and NBI colonoscopy. The MVP was determined to be normal or distorted under conventional colonoscopy and, subsequently, to be clear or obscure under NBI colonoscopy. The histologic variables in each segment were assessed in biopsy specimen. The possible correlation between MVP and the histologic grade of inflammation was evaluated. The MVP under conventional colonoscopy was normal in 60 segments while it was distorted in 97 segments. In all of the former 60 segments, their MVP was clear under NBI colonoscopy. The MVP in the latter 97 segments were determined to be clear (n = 44) or obscure (n = 53) under NBI colonoscopy. Acute inflammatory cell infiltrates (26% vs. 0%, p = 0.0001), goblet cell depletion (32% vs. 5%, p = 0.0006), and basal plasmacytosis (2% vs. 21%, p = 0.006) were more frequently observed in segments with an obscure MVP than in those with a clear MVP. NBI colonoscopy may be of value for determining the grade of inflammation in patients with quiescent UC.

Detectability of colorectal neoplastic lesions using a narrow‐band imaging system: A pilot study

Flat and depressed colorectal neoplastic lesions can be difficult to identify using conventional colonoscopy techniques. Narrow-band imaging (NBI) provides unique views especially of mucosal vascular network and helps in visualization of neoplasia by improving contrast. The aim of this study was to assess the feasibility of using NBI for colorectal neoplasia screening. Forty-seven consecutive patients, who underwent high definition colonoscopy (HDC) screening examinations revealing neoplastic lesions, were enrolled in our prospective study. No biopsies or resections were performed during the initial HDC, but patients in whom lesions were detected underwent further colonoscopies using NBI, with the results of the first examination blinded from the colonoscopist. They then received appropriate treatment. We compared diagnostic detection rates of neoplastic lesions for HDC and NBI procedures using total number of all identified neoplastic lesions as reference standard. Altogether, 153 lesions were detected and analyzed in 43 patients. Mean diagnostic extubation times were not significantly different (P = 0.18), but the total number of lesions detected by NBI was higher (134 vs 116; P = 0.02). Based on macroscopic type, flat lesions were identified more often by NBI (P = 0.04). As for lesion size, only flat lesions < 5 mm were detected more frequently (P = 0.046). Lesions in the right colon were identified more often by NBI (P = 0.02), but NBI missed two flat lesions >or= 10 mm located there. Narrow band imaging colonoscopy may represent a significant improvement in the detection of flat and diminutive lesions, but a future multi-center controlled trial should be conducted to fully evaluate efficacy for screening colonoscopies.

Narrow-band imaging colonoscopy with a transparent hood for more polyp detection

Narrow-band imaging colonoscopy with a transparent hood for more polyp detection

A randomised tandem colonoscopy trial of narrow band imaging versus white light examination to compare neoplasia miss rates

Objective:Colonoscopy, the “gold standard” screening test for colorectal cancer (CRC), has known diagnostic limitations. Advances in endoscope technology have focused on improving mucosal visualisation. In addition to increased angle of...

Can Magnification Narrow-Band Imaging (NBI) Colonoscopy Determine Invasion Depth of Early Colorectal Cancer? - A Prospective Study -

Can Magnification Narrow-Band Imaging (NBI) Colonoscopy Determine Invasion Depth of Early Colorectal Cancer? - A Prospective Study -

Narrow-band imaging optical chromocolonoscopy: Advantages and limitations

Narrow-band imaging (NBI) is an innovative optical technology that modifies the center wavelength and bandwidth of an endoscope's light into narrow-band illumination of 415 +/- 30 nm. NBI markedly improves capillary pattern contrast and is an in vivo method for visualizing microvessel morphological changes in superficial neoplastic lesions. The scientific basis for NBI is that short wavelength light falls within the hemoglobin absorption band, thereby facilitating clearer visualization of vascular structures. Several studies have reported advantages and limitations of NBI colonoscopy in the colorectum. One difficulty in evaluating results, however, has been non-standardization of NBI systems (Sequential and non-sequential). Utilization of NBI technology has been increasing worldwide, but accurate pit pattern analysis and sufficient skill in magnifying colonoscopy are basic fundamentals required for proficiency in NBI diagnosis of colorectal lesions. Modern optical technology without proper image interpretation wastes resources, confuses untrained endoscopists and delays inter-institutional validation studies. Training in the principles of "optical image-enhanced endoscopy" is needed to close the gap between technological advancements and their clinical usefulness. Currently available evidence indicates that NBI constitutes an effective and reliable alternative to chromocolonoscopy for in vivo visualization of vascular structures, but further study assessing reproducibility and effectiveness in the colorectum is ongoing at various medical centers.

Narrow-band imaging colonoscopy—a pilot feasibility study for the detection of polyps and correlation of surface patterns with polyp histologic diagnosis

Colonoscopy is the preferred screening method for colorectal cancer. However, it has a substantial miss rate for colon polyps, and several techniques have been attempted to improve this limitation. Narrow-band imaging (NBI) is a novel technology that enhances the visualization of surface mucosal and vascular patterns. The aim of this study was to determine the detection rate of additional polyps by NBI after removal of polyps visualized by standard white light colonoscopy (WLC) and to correlate the surface mucosal and vascular patterns with polyp histologic diagnosis. This was a prospective pilot feasibility study. Kansas City Veterans Affairs Medical Center. Subjects referred for screening colonoscopy were prospectively enrolled. Subjects underwent colonoscopy after enrollment. After intubation of the cecum, colonic segments were sequentially examined, initially with WLC with removal of polyps followed by re-examination of the same segment with NBI. Additional polyps seen with NBI were photographed for their surface patterns and then removed. The total number of polyps visualized by WLC and NBI was calculated and the surface patterns were then correlated with polyp histologic features. Forty patients were enrolled in the study, all men, 32 white. The mean age was 62 years. A total of 72 polyps were detected by WLC (43 tubular adenoma, 28 hyperplastic polyps), whereas NBI detected an additional 51 polyps, of which 29 were tubular adenomas and 22 were hyperplastic. Five different surface/vascular patterns were observed: fine capillary network with absent mucosal pattern, circular pattern with dots, round/oval pattern, tubular pattern, and gyrus pattern. The sensitivity, specificity, and overall accuracy of the first two patterns for hyperplastic polyps were 86%, 96%, and 92%, respectively, and of the latter three patterns for tubular adenomas were 96%, 86%, and 92%, respectively. This pilot study demonstrates the feasibility of polyp detection and histologic correlation with NBI. These findings need to be confirmed in future randomized controlled trials.

Magnifying colonoscopy with narrow band imaging system for the diagnosis of dysplasia in ulcerative colitis: a pilot study

Narrow-band imaging (NBI) is a novel illumination technology for endoscopy that enhances vasculature of the GI tract. The aim was to elucidate whether NBI colonoscopy can identify dysplasia in patients with ulcerative colitis (UC). Cross-sectional study of eligible patients. Single center. 46 patients with UC. Apparently flat mucosa at each segment and visible protruding lesions were observed by magnifying NBI colonoscopy. The surface structure was classified into honeycomb-like, villous, or tortuous pattern. The grade of dysplasia was determined in the specimens obtained from protrusions and from flat mucosa. The positive predictive value of conventional and NBI colonoscopy for the diagnosis of dysplasia. A total of 296 sites (20 protruding lesions and 276 flat areas) were examined by NBI colonoscopy. The surface pattern was determined to be honeycomb like in 161 sites, villous in 85 sites, and tortuous in 50 sites. Five dysplastic lesions were detected in 3 patients. A patient had 3 dysplastic lesions and the other 2 had a dysplastic lesion each. The positive rate of dysplasia was higher in protrusions (2/20 sites, 10%) than in flat mucosa (3/276 sites, 1.1%, P = .038; however, correction for the multiple testing of data removes this significance). When the surface pattern was taken into account, the rate of positive dysplasia was higher in the tortuous pattern (4/50 sites, 8%) than in the honeycomb-like or villous patterns (1/246 sites, 0.4%, P = .003). Uncontrolled study. The tortuous pattern determined by NBI colonoscopy may be a clue for the identification of dysplasia during surveillance for UC.

A prospective randomised study on narrow-band imaging versus conventional colonoscopy for adenoma detection: does narrow-band imaging induce a learning effect?

Background and aims:Colonoscopy is an established method of colorectal cancer screening, but has an adenoma miss rate of 10–20%. Detection rates are expected to improve with optimised visualisation methods. This...

AUTOFLUORESCENCE IMAGING COLONOSCOPY IN ULCERATIVE COLITIS: COMPARISON WITH CONVENTIONAL AND NARROW‐BAND IMAGING COLONOSCOPY

Autofluorescence imaging (AFI) endoscopy is a procedure to demonstrate gastrointestinal neoplasia and inflammation as colored areas distinct from the surrounding normal tissue. In the present pilot study AFI colonoscopy findings in patients with ulcerative colitis (UC) were analyzed. Ten patients with UC were examined using conventional colonoscopy, followed by AFI colonoscopy and narrow band imaging (NBI) colonoscopy. Images under AFI colonoscopy were classified into high AF (green or white) and low AF (magenta). NBI colonoscopy determined vasculature, either into regular, irregular or obscure mucosal vascular pattern. A total of 48 colorectal segments were assessed with the three modes of colonoscopy. The AF was high in 100% of the segments with normal mucosa or with quiescent disease and in 44% of the segments with active mucosa (P &lt; 0.001). Mucosal vascular pattern under NBI was obscure more frequently in low‐AF segments than in high‐AF segments (P &lt; 0.001). Inflammatory infiltrate was more severe and crypt distortion was more frequent in the latter than in the former (P &lt; 0.001). There were trends towards more frequent obscure vascular pattern and more severe inflammation in active segments with low AF than in those with high AF mucosa. These findings suggest that AF status determined by AFI colonoscopy may be a clue for subclassification of active UC.

Narrow-Band Imaging Endoscopy As a Novel Tool to Assess In Vivo Mucosal Angiogenesis in Inflammatory Bowel Disease: A Preliminary Report

Background: Angiogenesis is a novel component of inflammatory bowel disease (IBD) pathogenesis. We have recently reported that in both Crohn's disease (CD) and ulcerative colitis (UC) actively inflamed mucosa, there is an increase of microvascular density, as assessed by CD31 staining. Narrow-band imaging (NBI) is a novel endoscopic technique that preferentially enhances the mucosal surface and the network of superficial capillaries. We aimed to investigate if NBI could be a useful tool to detect in vivo angiogenesis in IBD patients. Methods: Conventional and NBI colonoscopy was performed on 9 patients (6 UC and 3 CD) with colonic inflammation. Based on the vascular pattern intensity with NBI, we distinguished areas with a stronger (blacker) capillary vascular pattern (NBI+) compared with normal mucosa showing regular vascular pattern (NBI−). For each patient, biopsy samples were taken in 5 endoscopically normal areas and NBI−, in 5 normal areas at conventional endoscopy but NBI+, and in 5 endoscopically inflamed areas and positive at NBI. CD31 staining was performed by immunohistochemistry, and microvascular density assessed by vessel count. Results: NBI allowed to clearly detect mucosal microvasculature in IBD intestine. NBI was able to visualize areas of abnormal microvascular changes, not detected at conventional colonoscopy. Compared to endoscopically normal areas at conventional colonoscopy and NBI-, areas with a normal mucosa at conventional colonoscopy but with a stronger capillary vascular pattern (NBI+) displayed a significant (p < 0.05) increase in angiogenesis (12 ± 1 versus 18 ± 2 vessels/field). Areas inflamed at conventional endoscopy and NBI+ displayed a significant (p < 0.01) increase in vessel density (24 ± 7 vessel/field) compared to endoscopically normal areas at conventional colonoscopy and NBI. Finally, a stronger vascular pattern of the colonic mucosa (NBI+) was significantly associated with an increase in leukocyte infiltrate as assessed at histological analysis compared to the areas in which both conventional and NBI endoscopy did not show significant mucosal changes. Conclusions: NBI may be a useful tool that may allow in vivo imaging of intestinal angiogenesis observed in IBD, and could be used in clinical trials aimed to monitor the clinical effect of anti-angiogenic compounds in IBD. Larger studies are warranted to validate this endoscopical technique.

Narrow Band Imaging (NBI) Influences the Learning Curve for Conventional Endoscopy - Final Results of a Prospective Randomized Study in the Detection of Colorectal Adenomas

Background: Results concerning staining and the use of the novel technology of narrow band imaging for the detection of colorectal adenomas are conflicting. It is well known from tandem colonoscopy studies that 15-20% of - mostly small - adenomas are missed. Staining has been proposed to increase the yield of especially flat adenomas, and intermediate results of Narrow Band Imaging (NBI), a new technique using different light filtering to increase contrast, have been encouraging with significantly more adenomas been found. Methods: Consecutive patients presenting for diagnostic colonoscopy with symptoms (pos. hemoccult, pain, diarrhea), for surveillance after polypectomy or for screening (cases with known tumors or IBD were excluded) were randomly allocated to NBI or conventional colonoscopy (Olympus Corp., Hamburg, Germany) according to availability of the instrument. The instrument was introduced as usual and on withdrawal from the cecum the control group (C) was examined conventionally with the NBI function not being activated, whereas the study group (NBI) was examined with NBI exclusively, with an option to switch back to normal imaging in case of uncertainty. These instances however were recorded and the reasons given. Polyp detection rate including polyp details as well as withdrawal time were recorded in both groups. Results: 401 patients (53% male, mean age 59 years) have been included; 5 cases with cancers were found but are excluded from this analysis. The overall rates of adenomas and hyperplastic polyps found were 19.7% and 19.9%, respectively. In the NBI group adenomas were detected in 22.7% compared to 16.7% in the control group, but this difference was statistically not significant (p = 0.129), neither in the entire group nor in any of the various subgroups (location, size, form). The number of colonoscopies to be performed to find one additional patient with adenoma would be 17 on the basis of the present adenoma difference. However, when comparing the first and the last 100 cases of the study, an initial significant different in adenoma rates ((NBI 26%, controls 8%, p = 0.015) was not sustained in the last 100 cases (27% vs. 19%, P = 0.33). Hyperplastic polyps were found more frequently in the NBI group than in controls (28.3% and 11.66%, p < 0.001). Conclusions: The new technique of NBI seems enhances the polyp detection rate in a high risk population, but this effect was present for adenomas only in the initial study period. Since the percentage of adenomas found in the control group increased with this rate being stable in the control group, a learning effect from NBI for conventional endoscopy could be postulated.

The Efficiency of Narrow Band Imaging with Magnification for the Estimation of Invasion Depth Diagnosis in Early Colorectal Cancer -A Prospective Study

Background: Narrow Band Imaging (NBI) colonoscopy has enabled the detailed observation of surface microstructure and capillary network of colorectal polyps, which have recently been reported to be useful in differentiating neoplastic from non-neoplastic lesions. We have previously reported in a retrospective review using standard magnification colonoscopy that lesions with either wide caliber or tortuous microvessels are significantly frequent in sm2-3 cancers. Aim: To clarify the efficiency of NBI system with magnification colonoscopy for the estimation of invasion depth.

Does Narrow Band Imaging (NBI) Colonoscopy Increase the Detection Rate of Colon Polyps? - A Pilot Feasibility Study

Does Narrow Band Imaging (NBI) Colonoscopy Increase the Detection Rate of Colon Polyps? - A Pilot Feasibility Study