PIT PATTERN DIAGNOSIS FOR COLORECTAL NEOPLASIA USING NARROW BAND IMAGING MAGNIFICATION

Pit pattern analysis of colorectal polyps using Storz professional image enhancement system (SPIES) endoscopy: A pilot study

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MORPHOLOGICAL CHARACTERIZATION OF COLORECTAL PITS USING AUTOFLUORESCENCE MICROSCOPY IMAGES

BACKGROUND

Colorectal cancer is one of the most prevalent pathologies. Its prognosis is linked to the early detection and treatment. Currently diagnosis is performed by histological analysis from polyp biopsies, followed by morphological classification. Kudo's pit pattern classification is frequently used for the differentiation of neoplastic colorectal lesions using hematoxylin-eosin stained samples. Few articles have reported this classification with image software processing, using exogenous markers over the samples. The processing of autofluorescence images is an alternative that could allow the characterization of the pits from the crypts of Lieberkühn, bypassing staining techniques.

OBJECTIVE

Processing and analysis of widefield autofluorescence microscopy images obtained by fresh colon tissue samples from a murine model of colorectal cancer in order to quantify and characterize the pits morphology by measuring morphology parameters and shape descriptors.

METHODS

Adult male BALB/cCmedc strain mice (n=27), ranging from 20 to 30 g, were randomly assigned to four and five groups of treated and control animals. Colon samples were collected at day zero and at fourth, eighth, sixteenth and twentieth weeks after treatmentwith azoxymethane. Two-dimensional (2D) segmentation, quantification and morphological characterization of pits by image processing applied using macro programming from FIJI.

RESULTS

Type I is the pit morphology prevailing between 53 and 81% in control group weeks. III-L and III-S types were detected in reduced percentages. Between the 33 and 56% of type I was stated as the prevailing morphology for the 4th, 8th and 20th weeks of treated groups, followed by III-L type. For the 16th week, the 39% of the pits was characterized as III-L type, followed by type I. Further, pattern types as IV, III-S and II were also found mainly in that order for almost all of the treated weeks.

CONCLUSION

These preliminaries outcomes could be considered an advance in two-dimensional pit characterization as the whole image processing, comparing to the conventional procedure, takes a few seconds to quantify and characterize non-pathological colon pits as well as to estimate early pathological stages of colorectal cancer.

The submucosal fibrosis: what does it mean for colorectal endoscopic submucosal dissection?

Background/Aims

Endoscopic submucosal dissection (ESD) allows removal of colorectal epithelial neoplasms en bloc regardless of size. Colorectal ESD is a difficult procedure because of technical difficulties and risks of complications. This study aimed to assess the relationship between ESD outcome and degree of submucosal fibrosis.

Methods

Patients with colorectal tumors undergoing ESD and their medical records were reviewed retrospectively. The degree of submucosal fibrosis was classified into three types. The relationship between ESD outcome and degree of submucosal fibrosis was analyzed.

Results

ESD was performed in 158 patients. Thirty-eight cases of F0 (no) fibrosis (24.1%) and 46 cases of F2 (severe) fibrosis (29.1%) were observed. Complete resection was achieved for 138 lesions (87.3%). Multivariate analysis demonstrated that submucosal invasion of tumor and histology of carcinoma were independent risk factors for F2 fibrosis. Severe fibrosis was an independent risk factor for incomplete resection.

Conclusions

Severe fibrosis is an important factor related to incomplete resection during colorectal ESD. In cases of severe fibrosis, the rate of complete resection was low even when ESD was performed by an experienced operator. Evaluation of submucosal fibrosis may be helpful to predict the submucosal invasion of tumors and technical difficulties in ESD.

Computer-aided diagnosis of colorectal polyp histology by using a real-time image recognition system and narrow-band imaging magnifying colonoscopy

BACKGROUND AND AIMS

It is necessary to establish cost-effective examinations and treatments for diminutive colorectal tumors that consider the treatment risk and surveillance interval after treatment. The Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) committee of the American Society for Gastrointestinal Endoscopy published a statement recommending the establishment of endoscopic techniques that practice the resect and discard strategy. The aims of this study were to evaluate whether our newly developed real-time image recognition system can predict histologic diagnoses of colorectal lesions depicted on narrow-band imaging and to satisfy some problems with the PIVI recommendations.

METHODS

We enrolled 41 patients who had undergone endoscopic resection of 118 colorectal lesions (45 nonneoplastic lesions and 73 neoplastic lesions). We compared the results of real-time image recognition system analysis with that of narrow-band imaging diagnosis and evaluated the correlation between image analysis and the pathological results.

RESULTS

Concordance between the endoscopic diagnosis and diagnosis by a real-time image recognition system with a support vector machine output value was 97.5% (115/118). Accuracy between the histologic findings of diminutive colorectal lesions (polyps) and diagnosis by a real-time image recognition system with a support vector machine output value was 93.2% (sensitivity, 93.0%; specificity, 93.3%; positive predictive value (PPV), 93.0%; and negative predictive value, 93.3%).

CONCLUSIONS

Although further investigation is necessary to establish our computer-aided diagnosis system, this real-time image recognition system may satisfy the PIVI recommendations and be useful for predicting the histology of colorectal tumors.

Polyp-Alert: near real-time feedback during colonoscopy

We present a software system called "Polyp-Alert" to assist the endoscopist find polyps by providing visual feedback during colonoscopy. Polyp-Alert employs our previous edge-cross-section visual features and a rule-based classifier to detect a polyp edge-an edge along the contour of a polyp. The technique employs tracking of detected polyp edge(s) to group a sequence of images covering the same polyp(s) as one polyp shot. In our experiments, the software correctly detected 97.7% (42 of 43) of polyp shots on 53 randomly selected video files of entire colonoscopy procedures. However, Polyp-Alert incorrectly marked only 4.3% of a full-length colonoscopy procedure as showing a polyp when they do not. The test data set consists of about 18 h worth of video data from Olympus and Fujinon endoscopes. The technique is extensible to other brands of colonoscopes. Furthermore, Polyp-Alert can provide as high as ten feedbacks per second for a smooth display of feedback. The performance of our system is by far the most promising to potentially assist the endoscopist find more polyps in clinical practice during a routine screening colonoscopy.

Two-stage optical system for colorectal polyp assessments

BACKGROUND AND AIMS

Macroscopic real-time evaluations of the histopathology and degree of invasion of colorectal polyps help to select the most suitable endoscopic treatment method. Dual-focus (DF) narrow-band imaging (NBI) is a new imaging enhancement system that uses digital and optical methods to enhance the view of blood vessels on mucosal surfaces. However, the superiority of this technique over standard imaging techniques has not been previously reported. The aim of this study was to determine whether the two-stage optical systems in a new generation of endoscopes will increase the diagnostic accuracy of colorectal polyp recognition.

METHODS

The study included 270 patients, and 386 colorectal polyps were diagnosed and removed. The polyps were assessed with white light and NBI using one- and two-stage optical systems, respectively. After being classified according to the Kudo pit pattern schemes, the polyps were removed and histopathologically verified.

RESULTS

Regarding non-neoplastic lesions (Kudo I and II), no difference was observed in the recognition of polyps when using the NBI-DF function. We observed improved accuracy in the preliminary diagnoses of Kudo IIIL lesions (from 87.16 to 90.09%, p < 0.05) and Kudo IIIS lesions (from 87.29 to 92.79%, p < 0.01). NBI-DF also increased the accuracy of preliminary diagnoses of Kudo IV lesions (from 88.24 to 94.12%, p < 0.01). The Kudo V pit patterns were also more distinct with NBI-DF imaging, increasing the diagnostic accuracy from 91.67 to 100%.

CONCLUSIONS

Using a two-stage optical system with electronic colorization of the mucosa increased diagnostic accuracy for differentiating colorectal polyps with neoplastic potential.

Risk factors for delayed bleeding after endoscopic submucosal dissection for colorectal neoplasms

PURPOSE

Although delayed bleeding is a major complication of endoscopic submucosal dissection (ESD) for colorectal neoplasms, few reports have assessed the risk factors for delayed bleeding after colorectal ESD.

METHODS

This study included 363 consecutive patients in whom 377 colorectal neoplasms were resected using ESD between April 2006 and August 2012. We classified patients and lesions into two groups on the basis of presence or absence of delayed bleeding and retrospectively compared the clinicopathological characteristics and clinical outcomes of ESD between the two groups.

RESULTS

Delayed bleeding occurred in 25 (6.6 %) of 377 lesions, and all cases of delayed bleeding were successfully controlled by endoscopic procedures. With respect to patient-related factors, there was no significant difference between the groups in mean age, sex ratio, and current use of antithrombotic agents. With respect to lesion-related factors, there was no significant difference between the groups in mean lesion size, growth pattern, and mean procedure time (p = 0.6). Lesions located in the rectum (vs colon, p = 0.0005) and lesions with severe submucosal fibrosis (vs no or mild fibrosis, p = 0.022) were significantly related to delayed bleeding. Upon multivariate analysis, lesions located in the rectum (vs colon, odds ratio 4.19; p = 0.0009) were significantly related to delayed bleeding after colorectal ESD.

CONCLUSIONS

This study demonstrated that location of lesions in the rectum was a significant independent risk factor for delayed bleeding after ESD for colorectal neoplasms.

Narrow band imaging to differentiate neoplastic and non-neoplastic colorectal polyps in real time: a meta-analysis of diagnostic operating characteristics

PURPOSE

Many studies have reported on the use of narrow band imaging (NBI) colonoscopy to differentiate neoplastic from non-neoplastic colorectal polyps. It has potential to replace pathological diagnosis of diminutive polyps. We aimed to perform a systematic review and meta-analysis on the real-time diagnostic operating characteristics of NBI colonoscopy.

METHODS

We searched PubMed, SCOPUS and Cochrane databases and abstracts. We used a two-level bivariate meta-analysis following a random effects model to summarise the data and fit hierarchical summary receiver-operating characteristic (HSROC) curves. The area under the HSROC curve serves as an indicator of the diagnostic test strength. We calculated summary sensitivity, specificity and negative predictive value (NPV). We assessed agreement of surveillance interval recommendations based on endoscopic diagnosis compared to pathology.

RESULTS

For NBI diagnosis of colorectal polyps, the area under the HSROC curve was 0.92 (95% CI 0.90 to 0.94), based on 28 studies involving 6280 polyps in 4053 patients. The overall sensitivity was 91.0% (95% CI 87.6% to 93.5%) and specificity was 82.6% (95% CI 79.0% to 85.7%). In eight studies (n=2146 polyps) that used high-confidence diagnostic predictions, sensitivity was 93.8% and specificity was 83.3%. The NPVs exceeded 90% when 60% or less of all polyps were neoplastic. Surveillance intervals based on endoscopic diagnosis agreed with those based on pathology in 92.6% of patients (95% CI 87.9% to 96.3%).

CONCLUSIONS

NBI diagnosis of colorectal polyps is highly accurate--the area under the HSROC curve exceeds 0.90. High-confidence predictions provide >90% sensitivity and NPV. It shows high potential for real-time endoscopic diagnosis.

Part-based multiderivative edge cross-sectional profiles for polyp detection in colonoscopy

This paper presents a novel technique for automated detection of protruding polyps in colonoscopy images using edge cross-section profiles (ECSP). We propose a part-based multiderivative ECSP that computes derivative functions of an edge cross-section profile and segments each of these profiles into parts. Therefore, we can model or extract features suitable for each part. Our features obtained from the parts can effectively describe complex properties of protruding polyps including the shape of the parts, texture, and protrusion and smoothness of the polyp surface. We evaluated our method against two existing polyp image detection techniques on 42 different polyps, including those with little protrusion. Each polyp has a large variation of appearance in viewing angles, light conditions, and scales in different images. The evaluation showed that our technique outperformed the existing techniques in both accuracy and analysis time. Our method has a higher area under the free-response receiver operating characteristic curve. For instance, when both techniques have a true positive rate for polyp image detection of 81.4%, the average number of false regions per image of our technique is 0.32 compared to 1.8 of the best existing technique under study. Additionally, our technique can precisely mark edges of candidate polyp regions as visual feedback. These results altogether indicate that our technique is promising to provide visual feedback of polyp regions in clinical practice.

Magnifying narrow-band imaging of surface patterns for diagnosing colorectal cancer

Narrow-band imaging (NBI) of surface microvessels of colorectal lesions is useful for differentiating neoplasms from non-neoplasms and for predicting histopathological diagnosis. Furthermore, NBI of surface microstructure, or 'surface pattern', is valuable for predicting histopathology in colorectal cancer. The aim of the present study was to investigate whether surface patterns could be used to predict invasion depth in colorectal cancer, and to compare the accuracy of surface pattern diagnosis in each macroscopic type. Between January 2010 and March 2011, a series of 357 consecutive patients with 378 early colorectal cancers were observed by magnifying NBI and the surface pattern was prospectively evaluated. Surface pattern was classified into 3 types: type I, microstructure was clearly recognised with uniform arrangement and form; type II, microstructure was obscured with heterogeneous arrangement and form; and type III, microstructure was invisible. We also classified the macroscopic type into 3 categories: depressed, protruded and flat elevated. Assuming that type III was an index of massively invasive lesions in the submucosal layer (SMm), the sensitivity, specificity and accuracy were 56.9, 91.7 and 85.7%, respectively. The sensitivity, specificity and accuracy of type III for the diagnosis of SMm in each macroscopic type were: depressed, 88.9, 40.0 and 63.2%, respectively; protruded: 34.8, 96.4 and 90.0%, respectively; and flat elevated, 54.2, 92.7 and 85.0%, respectively. These results suggest that the diagnostic accuracy of surface pattern was insufficient and particularly poor for depressed-type lesions.

Characteristic magnifying narrow-band imaging features of colorectal tumors in each growth type

PURPOSE

We investigated the surface characteristics and vascular patterns of colorectal tumors according to growth type by means of magnifying narrow-band imaging (NBI).

METHODS

Four hundred ninety-seven colorectal tumors larger than 10 mm (204 tubular adenomas [TAs], 199 frankly invasive intramucosal carcinomas to shallow invasive submucosal [M/SM-s] carcinomas, and 94 deeply invasive submucosal [SM-d] carcinomas) were analyzed. These colorectal tumors were classified according to growth type as follows: polypoid type, n = 224; laterally spreading tumor-granular (LST-G) type, n = 133; and LST-non-granular (LST-NG) type, n = 140. Surface and vascular patterns were evaluated in relation to histology and growth type.

RESULTS

The absent and irregular surface patterns were observed in approximately 40 % of the SM-d carcinomas of the polypoid and LST-G type. The unclear surface pattern was more frequent in tumors of the LST-NG type than in those of other growth types, regardless of histology. Among TAs and M/SM-s carcinomas, the dense vascular pattern was most frequent in polypoid type, the dense and corkscrew vascular patterns were most frequent in the LST-G type, and the honeycomb and avascular and/or fragmentary patterns were most frequent in the LST-NG type. The avascular and/or fragmentary vessel pattern was more frequent in SM-d carcinomas than in TA and M/SM-s carcinomas, regardless of growth type.

CONCLUSIONS

A part of LST-NG was difficult to identify the NBI magnifying surface pattern. Although NBI magnifying findings were almost same in each type lesion in SM-d lesion, those of LST-NG were different from those of LST-G and polypoid type in M/SM-s lesion.

Meta-analysis for evaluating the accuracy of endoscopy with narrow band imaging in detecting colorectal adenomas

BACKGROUND AND AIM

The aim of this study was to determine whether the use of the narrow band imaging (NBI) system could enhance the accuracy of adenoma detection during an endoscopic examination of the colon and rectum.

METHODS

MEDLINE, EMBASE, and the Cochrane Library databases were searched along with a hand search of abstracts from relevant conferences up to June 2011. The rates of adenoma and flat adenoma detection, and withdrawal time were analyzed using Review Manager 4.2.

RESULTS

A total of 3049 subjects in eight trials were included. Meta-analysis revealed that there was no statistically significant difference in the rates of adenoma detection between the NBI group and the white light colonoscopy group (pooled relative risk [RR]: 1.09, 95% confidence interval [CI]: 1.00-1.19, P = 0.05). However, after exclusion of high-definition television modalities, the rate of adenoma detection by NBI was significantly higher than that by white light, particularly for patients with one adenoma (pooled RR 1.36, 95%CI 1.07-1.71, P = 0.02). Endoscopy with the NBI system significantly increased the rate of flat adenoma detection (pooled RR 1.96, 95%CI 1.09-3.52, P = 0.02). However, endoscopy with NBI had longer withdrawal time than that with white light (pooled weighted mean difference: 0.90, 95%CI: 0.38-1.42, P = 0.0006).

CONCLUSIONS

Endoscopy with NBI seems to improve the detection of flat adenomas, particularly with high-definition technology, but prolongs the withdrawal time. These results indicate that endoscopy routinely using the NBI system for the surveillance of adenomas may be recommended after the technique is further modified.

Clinical outcomes of endoscopic submucosal dissection and endoscopic mucosal resection for laterally spreading tumors larger than 20 mm

BACKGROUND AND AIMS

Colorectal laterally spreading tumors (LST) > 20 mm are usually treated by endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR). Endoscopic piecemeal mucosal resection (EPMR) is sometimes required. The aim of our study was to compare the outcomes of ESD and EMR, including EPMR, for such LST.

METHODS

A total of 269 consecutive patients with a colorectal LST > 20 mm were treated endoscopically at our hospital from April 2006 to December 2009. We retrospectively evaluated the complications and local recurrence rates associated with ESD, hybrid ESD (ESD with EMR), EMR, and EPMR.

RESULTS

ESD and EMR were performed successfully for 89 and 178 LST, respectively: 61 by ESD; 28 by hybrid ESD; 70 by EMR; and 108 by EPMR. Between-group differences in perforation rates were not significant. Local recurrence rates in cases with curative resection were as follows: 0% (0/56) in ESD; 0% (0/27) in hybrid ESD; 1.4% (1/69) in EMR; and 12.1% (13/107) in EPMR; that is, significantly higher in EPMR. No metastasis was seen at follow up. The recurrence rate for EPMR yielding ≥ three pieces was significantly high (P < 0.001). All 14 local recurrent lesions were adenomas that were cured endoscopically.

CONCLUSIONS

As for safety, ESD/hybrid ESD is equivalent to EMR/EPMR. ESD/hybrid ESD is a feasible technique for en bloc resection and showed no local recurrence. Although local recurrences associated with EMR/EPMR were seen, which were conducted based on our indication criteria, all local recurrences could obtain complete cure by additional endoscopic treatment.

Correlation of narrow band imaging with magnifying colonoscopy and histology in colorectal tumors

Background/Aims

Narrow band imaging (NBI) is a new technique that uses optical filters for imaging of mucosal morphology. The aim of this study was to correlate findings of NBI with magnifying colonoscopy and histology for prediction of neoplastic colorectal lesion.

Methods

Between September 2005 and December 2007, 107 colon polyps from 68 patients were detected by conventional colonoscopy and subsequently evaluated by NBI with magnifying colonoscopy and analyzed for a pit pattern and a capillary pattern. More analysis was done regarding thickness and irregularity of capillary features.

Results

Pit pattern with NBI magnification to discriminate between neoplastic and non-neoplastic lesions had a sensitivity of 88.9% and a specificity of 87.5%; capillary pattern yielded test performance characteristics of 91.9% and 87.5%. In respect of capillary thickness, invisible capillaries were found significantly more often in hyperplastic lesions. All thick capillaries were found in neoplastic polyps, and found significantly more often in carcinomas with submucosal massive invasion (sm-m) (p<0.01). In respect of capillary irregularity, invisible capillaries were found significantly more often in hyperplasic lesions, and severely irregular capillaries were found significantly more often in sm-m lesions (p<0.01).

Conclusions

Observation of capillary thickness and irregularity by NBI magnification is useful for correlating histological grade with carcinoma, especially with depth of submucosal invasion.

Proceedings of a preliminary workshop at Gastro 2009--narrow banding imaging in digestive endoscopy: clinical outcome of classification (Omed-Jges Educational Meeting held on 22 November, 2009)

This publication reports the proceedings of the preliminary meeting of the working party that met at Gastro 2009 during the World Congress in London. The purpose of the preliminary meeting was to consider the areas that require attention, to discuss some of the findings that have already been published and to agree on the way forward. Our reason for publishing these proceedings is to stimulate interest in this venture and to provide the opportunity for input from the endoscopy community worldwide. The next meeting of the working party will be at the JGES Society meeting in Aomori in April 2011 when we hope to prepare a preliminary classification. This will be presented for general discussion and debate at the International Congress of Endoscopy (ICE) in Los Angeles in September 2011.

Clinical usefulness of narrow band imaging magnifying classification for colorectal tumors based on both surface pattern and microvessel features

We use the narrow band imaging (NBI) magnifying classification (Hiroshima Classification) on the basis of both their surface pattern and microvascular architecture to characterize colorectal tumors. Herein, we describe the Hiroshima Classification in detail and provide statistical data supporting its usefulness in diagnosing histologic type, whether a hyperplastic lesion, tubular adenoma, carcinoma with intramucosal to submucosal scanty invasion or carcinoma with submucosal massive invasion, and thus in selecting the appropriate treatment strategy. We also discuss the circumstances in which the Hiroshima Classification must be augmented by conventional pit pattern diagnosis. NBI magnification is easily carried out. We strongly recommend application of NBI magnification to the differential diagnosis of colorectal lesions as well as treatment decision making.

Vascular pattern classification of colorectal lesions with narrow band imaging magnifying endoscopy

Magnifying narrow band imaging (NBI) has enabled to observe the vascular pattern of colorectal lesions. Their broad findings have been divided into six groups according to endoscopical vascular features: normal, faint, network, dense, irregular and sparse. Most hyperplastic polyps show a faint pattern. The vascular patterns of adenomas are mainly network or dense ones. The predominant vascular patterns of cancer were irregular and sparse. Indeed, irregular pattern has found to be characteristic for protruded or flat-elevated cancer, whereas sparse pattern unique for depressed cancer. Through NBI, neoplastic lesions could be differentiated from those non-neoplastic with sensitivity of 83.5%, specificity of 98.7% and accuracy of 98.2%. It was able to distinguish between massively submucosal invasive cancers and slightly submucosal invasive cancers by using the vascular pattern with 91.0% sensitivity and 79.4% specificity. The overall accuracy was 88.3%. NBI system has showed to be a valuable technique for distinguishing neoplastic from non-neoplastic lesions, as well as massively from slightly submucosal invasive cancer. Therefore, vascular pattern analysis might be a promising tool for determining treatment selection, whether endoscopical or surgically.

Aim to unify the narrow band imaging (NBI) magnifying classification for colorectal tumors: current status in Japan from a summary of the consensus symposium in the 79th Annual Meeting of the Japan Gastroenterological Endoscopy Society

At present, there are many narrow band imaging (NBI) magnifying observation classifications for colorectal tumor in Japan. To internationally standardize the NBI observation criteria, a simple classification system is required. When a colorectal tumor is closely observed using the recent high-resolution videocolonoscope, a pit-like pattern on the tumor can be observed to a certain degree without magnification. In the symposium we could have a consensus that we will name the pit-like pattern as 'surface pattern.' Using the NBI system, the microvessels on the tumor surface can also be recognized to a certain degree. When the NBI system is used, the structure is emphasized, and consequently, the surface pattern can be recognized easily. Recently, an international cooperative group was formed and consists of members from Japan, the USA and Europe, which is named as the Colon Tumor NBI Interest Group. This group has developed a simple category classification (NBI international colorectal endoscopic [NICE] classification), which classifies colorectal tumors into types 1-3 even by closely observing colorectal tumors using a high-resolution videocolonoscope (Validation study is now ongoing by Colon Tumor NBI Interest Group.). The key advantage of this is simplification of the NBI classification. Although the magnifying observation is the best for getting detailed NBI findings, both close observation and magnifying observation using the NICE classification might give almost similar results. Of course the NICE classification can be used more precisely with magnification. In this report we also refer the issues on NBI magnification, which should be solved as early as possible.

Autofluorescence imaging with a transparent hood for detection of colorectal neoplasms: a prospective, randomized trial

BACKGROUND

Colonoscopy is one of the most reliable methods for detection of colorectal neoplasms, but conventional colonoscopy can miss some lesions.

OBJECTIVE

To evaluate the efficacy of autofluorescence imaging (AFI) with a transparent hood (TH) for detection of colorectal neoplasms.

DESIGN

A 2 × 2 factorial designed, prospective, randomized, controlled trial.

SETTING

This study was conducted at the Osaka Medical Center for Cancer and Cardiovascular Diseases, a tertiary cancer center.

PATIENTS

A total of 561 patients.

INTERVENTIONS

Patients were allocated to 1 of 4 groups: (1) white light imaging (WLI) alone--colonoscopy using WLI without a TH; (2) WLI+TH--colonoscopy using WLI with a TH; (3) AFI alone--colonoscopy using AFI without a TH; and (4) AFI+TH--colonoscopy using AFI with a TH. Eight colonoscopists used each allocated method.

MAIN OUTCOME MEASUREMENT

The difference in neoplasm detection rate (number of detected neoplasms per patient) between the WLI alone and AFI+TH groups.

RESULTS

Neoplasm detection rate (95% confidence interval) in the AFI+TH group was significantly higher than in the WLI alone group (1.96 [1.50-2.43] vs 1.19 [0.93-1.44]; P = .023, Tukey-Kramer multiple comparison test). Relative detection ratios (95% confidence interval) for polypoid neoplasms based on Poisson regression model were significantly increased by mounting a TH (1.69 [1.34-2.12], P < .001), and relative detection ratios for flat neoplasms were significantly increased by AFI observation (1.83 [1.24-2.71], P = .002).

LIMITATIONS

Open trial performed in single cancer referral center.

CONCLUSION

AFI colonoscopy with a TH detected significantly more colorectal neoplasms than did conventional WLI colonoscopy without a TH.

Computerized virtual chromoendoscopy versus indigo carmine chromoendoscopy combined with magnification for diagnosis of small colorectal lesions: a randomized and prospective study

BACKGROUND AND STUDY AIMS

Magnifying colonoscopy with indigo carmine dye and the analysis of the capillary and the pit patterns by computed virtual chromoendoscopy (Fujinon Intelligent Color Enhancement, FICE) with magnification are effective for the differential diagnosis of neoplastic and non-neoplastic lesions. This study aimed to compare the accuracy of virtual and real chromoendoscopy in differentiating neoplastic and non-neoplastic colorectal lesions.

PATIENTS AND METHODS

A prospective randomized trial of magnification colonoscopy with targeted FICE (Group I - 72 patients/111 lesions) versus magnification colonoscopy with targeted indigo carmine dye (Group II - 72 patients/137 lesions) was performed in consecutive patients with lesions 1 cm or less. Histopathology of the specimens was regarded as the gold standard.

RESULTS

In group I, 86 (77.5%) lesions showed an intense vascular pattern (positive capillary meshwork), of which 80 (93%) were histologically confirmed as adenomas. From 25 lesions with negative capillary meshwork, 23 (92%) were non-neoplastic. Sensitivity, specificity, accuracy, positive and negative predictive values of the capillary meshwork for the differential diagnosis of these lesions was 97.8, 79.3, 92.8, 93 and 92%, respectively. The same parameters for pit pattern analysis by FICE were 92.7, 82.3, 90.1, 93.8 and 80%, respectively. Indigo carmine magnified chromoscopy showed sensitivity, specificity, accuracy, positive and negative predictive values of 97, 88.9, 94.9, 96.1 and 91.4%, respectively in the discrimination between neoplastic and non-neoplastic lesions.

CONCLUSION

Magnified virtual chromoendoscopy is as accurate as indigo carmine magnified chromoendoscopy in distinguishing between neoplastic from non-neoplastic small colorectal lesions.

Characterization of colorectal tumors using narrow-band imaging magnification: combined diagnosis with both pit pattern and microvessel features

OBJECTIVE

We aimed to clarify the clinical usefulness of narrow-band imaging (NBI) magnification for evaluating both pit appearances and microvessel architecture in comparison with evaluation of microvessel architecture alone in invasion depth of colorectal tumors.

MATERIAL AND METHODS

A total of 189 colorectal lesions [37 adenomas, 73 intramucosal to scanty submucosal invasive carcinomas and 79 massive submucosal invasive (SM-m) carcinomas] were analyzed. All lesions showing irregular pit structure were observed by NBI magnifying endoscopy. Based on both pit appearance and microvessel features, lesions were classified into three grades (C1, C2, C3), as described previously. Also, lesions were classified as high or low by microvessel irregularity. Furthermore, the histopathological background and the inter- and intraobserver variability of C subtype were assessed.

RESULTS

The SM-m rate of C1, C2 and C3 was 5.2, 60.5 and 92.7%, respectively. On the other hand, SM-m rate of lesion with mildly and highly irregular vessels was 13.3 and 55.0%, respectively. For the histopathological background, a high percentage of destruction of the glandular orifice, disappearance of the lamina muscularis mucosae and superficial exposure of desmoplastic reaction (DR) were observed in type C3. For C subtype classification of NBI magnification findings, the kappa value for interobserver variability was 0.749, and the kappa value for intraobserver variability was 0.745.

CONCLUSIONS

NBI magnification findings evaluated by both pit appearances and microvessel features (C subtype) showing a good kappa value in variability are more useful in invasion depth diagnosis of colorectal tumor than those evaluated by microvessel features alone.

Diagnostic accuracy of pit pattern and vascular pattern analyses in colorectal lesions

BACKGROUND

The aim of this prospective study is to compare the usefulness of magnifying narrow band imaging (NBI) and magnifying chromoendoscopy in the diagnosis of colorectal lesions.

METHODS

The subjects were 1185 patients who underwent a complete colonoscopic examination and endoscopic or surgical treatment, from January 2006 to February 2008. A total of 1473 lesions were evaluated (53 hyperplastic polyps, 1317 adenomas, 103 submucosally invasive cancers). The digital images with NBI or chromoendoscopy were recorded and diagnosed independently from each other by two endoscopists who were blinded to the final pathological diagnosis.

RESULTS

We could differentiate between neoplastic and non-neoplastic lesions with sensitivity of 88.9%, specificity of 98.5% and accuracy of 98.2% according to the vascular pattern. By recognizing an irregular or sparse pattern with NBI, massively invasive submucosal cancer could be diagnosed with the sensitivity and specificity of 94.9% and 76.0%. Using chromoendoscopy, we could differentiate between neoplastic and non-neoplastic lesions with sensitivity of 86.8% and specificity of 99.2%. We were able to differentiate between massively invasive cancers and slightly invasive cancers using the pit patterns with sensitivity of 89.7% and specificity of 88.0%. The specificity was superior to that of NBI colonoscopy.

CONCLUSION

Both NBI and chromoendoscopy can be useful for distinguishing between neoplastic and non-neoplastic lesions. In the diagnosis of submucosal cancer, pit pattern diagnosis was slightly superior to vascular pattern diagnosis. It is desirable to perform chromoendoscopy in addition to NBI for distinguishing between slightly and massively invasive submucosal cancer lesions and determining the treatment.

Surveillance colonoscopy using a transparent hood and image-enhanced endoscopy

Colonoscopists can miss adenomas during colonoscopy screening. A transparent hood attached to the tip of the colonoscope helps detection of colorectal adenomas, but as far as we are aware, there has been no trial indicating its statistically significant effectiveness. Total colonic dye spray might improve the adenoma detection rate but it is complicated and time-consuming for routine clinical usage. Moreover, the efficacy of narrow band imaging for detection of colorectal adenoma is controversial and is still under debate. Autofluorescence imaging (AFI) might be better able to detect flat lesions than white light imaging (WLI), but its ability is influenced easily by the area of the observation. Therefore, we have attached a transparent hood to the tip of an AFI colonoscope during colonoscopy screening in clinical usage. AFI can detect a flat lesion, which is difficult to detect using WLI. A transparent hood can help to detect lesions behind the folds by pushing the colonic fold. We expect that mounting a transparent hood would work complimentary to AFI. Further improvements, including a combination of AFI and a transparent hood, are needed and they would provide optimal surveillance intervals.

Estudo comparativo entre MBI (FICE®) e a magnificação com índigo-carmin no diagnóstico diferencial de lesões neoplásicas e não-neoplásicas de cólon e reto

CONTEXTO: O uso da cromoscopia virtual com sistema de imagem multibanda poderia auxiliar no diagnóstico in vivo de neoplasias colônicas. Objetivo - Avaliar a exatidão da magnificação associada à cromoendoscopia eletrônica ou com índigo-carmin na distinção entre lesões neoplásicas e não-neoplásicas do cólon e reto. MÉTODOS: Foram avaliadas prospectivamente 157 lesões colorretais em 75 pacientes. Empregou-se o sistema FICE® para a análise dos padrões de capilares, com a malha capilar negativa sendo considerada padrão de lesões não-neoplásicas, e a malha capilar positiva, o padrão das neoplasias. Após esta avaliação, ainda usando o sistema FICE®, o padrão de criptas foi definido conforme a classificação de Kudo. Por fim, instilou-se índigo-carmin à 0,8% e outro estudo das criptas foi realizado. RESULTADOS: Entre as 157 lesões colorretais, classificou-se 116 como malha capilar positiva, sendo 115 confirmadas histologicamente como neoplasias. Já entre as 41 lesões com malha capilar negativa, 32 eram não-neoplásicas. A sensibilidade foi de 92,7%, a especificidade de 97% e a precisão de 93,6%. Os padrões de criptas tipo I e II representaram as lesões não-neoplásicas e os tipos III-V, as neoplásicas. Com a utilização da cromoscopia eletrônica, observou-se sensibilidade de 94,4%, especificidade de 97% e precisão de 94,9%. Já com o uso da magnificação associada ao índigo-carmin, a sensibilidade foi de 97,6%, a especificidade de 93,9% e a precisão de 96,8%. CONCLUSÕES: Tanto a cromoendoscopia eletrônica, quanto o uso do índigo-carmin, associados à magnificação de imagens, apresentaram precisão elevada quanto ao diagnóstico histopatológico e não houve diferença estatística entre ambos os métodos.

Narrow-band imaging without high magnification to differentiate polyps during real-time colonoscopy: improvement with experience

BACKGROUND

There is no widely adopted, easily applied method for distinguishing between adenomatous and nonadenomatous polyps during real-time colonoscopy.

OBJECTIVE

To compare white light (WL) with narrow-band imaging (NBI) for the differentiation of colorectal polyps in vivo and to assess for a learning curve.

DESIGN

A prospective polyp series.

PATIENTS AND SETTING

A total of 302 patients referred for colonoscopy, between August 2006 and July 2007, to a single tertiary-referral center in the United States.

INTERVENTION

Standard WL colonoscopy was performed with Olympus 180-series colonoscopes. Each detected polyp was first characterized by WL and then by NBI. Modified Kudo pit pattern and vascular color intensity (VCI) were recorded, and the histology was predicted. Endoscopists were given feedback every 2 weeks.

MAIN OUTCOME MEASUREMENTS

Overall accuracy and sensitivity and specificity of endoscopic diagnosis by using WL alone and with NBI, as well as improvement in endoscopists' performance.

RESULTS

A total of 265 polyps were found in 131 patients. Diagnostic accuracy was 80% with NBI and 77% with WL (P = .35). NBI performed better than WL in diagnosing adenomas (sensitivity 80% vs 69%, P < .05). Nonadenomatous polyps were more likely to have a "light" VCI compared with adenomas (71% vs 29%, P < .001). During the second half of the study, NBI accuracy improved, from 74% to 87%, and outperformed an unchanged WL accuracy of 79% (P < .05).

CONCLUSIONS

Overall, NBI was not more accurate than WL in differentiating colorectal polyps in vivo; however, once a learning curve was achieved, NBI performed significantly better. Further refinements of an NBI pit-pattern classification and VCI scale are needed before broad application to clinical decisions regarding the necessity of polypectomy.

Evaluation of microvessels in colorectal tumors by narrow band imaging magnification

BACKGROUND

Narrow band imaging (NBI) uses optical filters for sequential green and blue illumination and narrows the bandwidth of spectral transmittance.

OBJECTIVE

We determined the clinical usefulness of NBI magnification for evaluation of microvascular architecture and qualitative diagnosis of colorectal tumors.

DESIGN

This study was a retrospective study.

SETTING

Department of Endoscopy, Hiroshima University, Hiroshima, Japan.

PATIENTS AND MAIN OUTCOME MEASUREMENTS

A total of 189 colorectal lesions were analyzed. Each lesion was observed by NBI magnifying endoscopy and classified according to microvascular features (ie, thickness and irregularity). Microvessel thickness was classified as invisible, thin, or thick, and microvessel irregularity was classified as invisible, regular, mildly irregular, or severely irregular. NBI endoscopic images were compared with histologic findings.

RESULTS

With respect to microvessel thickness, invisible microvessels were found significantly more often in hyperplasia lesions, and thick microvessels were found significantly more often in carcinoma with submucosal massive invasion (sm-m) (P < .01). With respect to microvessel irregularity, invisible microvessels were found significantly often in hyperplasia lesions, and severely irregular microvessels were found significantly often in sm-m lesions (P < .01). Accuracy of diagnosis of sm-m on the basis of thick and severely irregular lesions was 100%.

CONCLUSION

Microvascular features determined by NBI magnification are associated with histologic grade and depth of submucosal invasion. These results indicate that NBI magnification is useful for the prediction of histologic diagnosis and selection of therapeutic strategies of colorectal tumors.