Colonoscopy For Detection Of Polyps Research Articles

Benchmarking definitions of false-positive alerts during computer-aided polyp detection in colonoscopy.

The occurrence of false-positive alerts is an important outcome measure in computer-aided colon polyp detection (CADe) studies. However, there is no consensus definition of a false positive in clinical trials evaluating CADe in colonoscopy. We aimed to study the diagnostic performance of CADe based on different threshold definitions for false-positive alerts. A previously validated CADe system was applied to screening/surveillance colonoscopy videos. Different thresholds for false-positive alerts were defined based on the time an alert box was continuously traced by the system. Primary outcomes were false-positive results and specificity using different threshold definitions of false positive. 62 colonoscopies were analyzed. CADe specificity and accuracy were 93.2 % and 97.8 %, respectively, for a threshold definition of ≥ 0.5 seconds, 98.6 % and 99.5 % for a threshold definition of ≥ 1 second, and 99.8 % and 99.9 % for a threshold definition of ≥ 2 seconds. Our analysis demonstrated how different threshold definitions of false positive can impact the reported diagnostic performance of CADe for colon polyp detection.

Diagnostic accuracy of capsule endoscopy compared with colonoscopy for polyp detection: systematic review and meta-analyses.

Colon capsule endoscopy (CCE) is a technology that might contribute to colorectal cancer (CRC) screening programs as a filter test between fecal immunochemical testing and standard colonoscopy. The aim was to systematically review the literature for studies investigating the diagnostic yield of second-generation CCE compared with standard colonoscopy. A systematic literature search was performed in PubMed, Embase, and Web of Science. Study characteristics including quality of bowel preparation and completeness of CCE transits were extracted. Per-patient sensitivity and specificity were extracted for polyps (any size, ≥ 10 mm, ≥ 6 mm) and lesion characteristics. Meta-analyses of diagnostic yield were performed. The literature search revealed 1077 unique papers and 12 studies were included. Studies involved a total of 2199 patients, of whom 1898 were included in analyses. The rate of patients with adequate bowel preparation varied from 40 % to 100 %. The rates of complete CCE transit varied from 57 % to 100 %. Our meta-analyses demonstrated that mean (95 % confidence interval) sensitivity, specificity, and diagnostic odds ratio were: 0.85 (0.73-0.92), 0.85 (0.70-0.93), and 30.5 (16.2-57.2), respectively, for polyps of any size; 0.87 (0.82-0.90), 0.95 (0.92-0.97), and 136.0 (70.6-262.1), respectively, for polyps ≥ 10 mm; and 0.87 (0.83-0.90), 0.88 (0.75-0.95), and 51.1 (19.8-131.8), respectively, for polyps ≥ 6 mm. No serious adverse events were reported for CCE. CCE had high sensitivity and specificity for per-patient polyps compared with standard colonoscopy However, the relatively high rate of incomplete investigations limits the application of CCE in a CRC screening setting.

An Adaptive Regularization Approach to Colonoscopic Polyp Detection Using a Cascaded Structure of Encoder–Decoders

This research aims to segment colonoscopic images by automatically extracting polyp features by exploiting the strengths of convolution neural networks (CNN). The proposed model employs deep learning and adaptive regularization techniques. The model is structurally composed of two cascaded encoder–decoder networks, each of which is constructed by four CNN layers and two full connection layers. The front model is built on backpropagation learning for segmenting a colonoscopic polyp image. The output images from the precedent hetero-encoder are regarded as corrupted labeled images, especially during the time period close to the end of learning, and are selectively fed into the successive auto-encoder for denoising learning to enhance its discriminative power and relieve the problem of a lack of labeled data for medical image tasks. The performance of the proposed model can be further improved by a simple fuzzy logic approach setting the regularization parameter in the loss function. The proposed method utilizes features learned from some open medical datasets and our own collected dataset. The performance of the proposed architecture is compared with a state-of-the-art network. The evaluation shows the performances of the proposed method are consistent across all the datasets and often outperform the state-of-art model.

Clinical application of simethicone emulsion on bowel preparation for colonoscopy

Objective To assess the clinical effects of simethicone emulsion combined with polyethylene glycol on bowel preparation for colonoscopy. Methods Two hundred out-patients, who underwent colonoscopy, were randomly divided into the study group and the control group. The study group was given simethicone in addition with polyethylene glycol, and the control group was given polyethylene glycol only. The differences on bowel preparation scores, air bubble reduction rate, colon lens sharpness, ileocecal region arrival time, colon polyp detection rate, the number of colon poly detection, and adverse event rate between the two groups were compared. Results The air bubble reduction rate, colon lens sharpness score and ileocecal region arrival time of the study group was 1(0-3) score, 1.0(0-2) score, and 9 (5-21) min, respectively, which was 2 (1-3) score, 1.5 (0-2) score and 12 (6-22) min, respectively in the control group. Differences between the two groups were statistically significant(Z=-9.490, P=0.000; Z=-6.768, P=0.000; Z=-5.521, P=0.000). For the bowel preparation score, colonoscopy polyp detection rate, the detection rate of colon polyp of diameter less than 5 mm, and number of colonoscopy polyp detection, there was no statistical difference between the two groups (P>0.05). No adverse events were observed in the both two groups. Conclusion The bowel preparation using simethicone combined with polyethylene glycol could effectively decrease the number of air bubble, enhance colon lens sharpness and shorten operation time, which contributes significant improvement for colonoscopy quality. Key words: Colonoscopy; Bowel preparation; Simethicone; Polyethylene glycol

Heuristic Classifier for Observe Accuracy of Cancer Polyp Using Video Capsule Endoscopy

Methods:Colonoscopy is a technique for examine colon cancer, polyps. In endoscopy, video capsule is universally used mechanism for finding gastrointestinal stages. But both the mechanisms are used to find the colon cancer or colorectal polyp. The Automatic Polyp Detection sub-challenge conducted as part of the Endoscopic Vision Challenge (http://endovis.grand-challenge.org).Method:Colonoscopy may be primary way of improve the ability of colon cancer detection especially flat lesions. Which otherwise may be difficult to detect. Recently, automatic polyp detection algorithms have been proposed with various degrees of success. Though polyp detection in colonoscopy and other traditional endoscopy procedure based images is becoming a mature field, due to its unique imaging characteristics, detecting polyps automatically in colonoscopy is a hard problem. So the proposed video capsule cam supports to diagnose the polyps accurate and easy to identify its pattern. Existing methodology mainly concentrated on high accuracy and less time consumption and it uses many different types of data mining techniques. To analyse these high resolution video scale image we have to take segmentation of image in pixel level binary pattern with the help of a mid-pass filter and relative gray level of neighbours. This work consists of three major steps to improve the accuracy of video capsule endoscopy such as missing data imputation, high dimensionality reduction or feature selection and classification. The above steps are performed using a dataset called endoscopy polyp disease dataset with 500 patients. Our binary classification algorithm relieves human analyses using the video frames. SVM has given major contribution to process the dataset.Results:In this paper the key aspect of proposed results provide segmentation, binary pattern approach with Genetic Fuzzy based Improved Kernel Support Vector machine (GF-IKSVM) classifier. The segmented images all are mostly round shape. The result is refined via smooth filtering, computer vision methods and thresholding steps.Conclusion:Our experimental result produces 94.4% accuracy in that the proposed fuzzy system and genetic Fuzzy, which is higher than the methods, used in the literature. The GF-IKSVM classifier is well-organized and provides good accuracy results for patched VCE polyp disease diagnosis.

Polyp Detection and Segmentation from Video Capsule Endoscopy: A Review

Video capsule endoscopy (VCE) is used widely nowadays for visualizing the gastrointestinal (GI) tract. Capsule endoscopy exams are prescribed usually as an additional monitoring mechanism and can help in identifying polyps, bleeding, etc. To analyze the large scale video data produced by VCE exams, automatic image processing, computer vision, and learning algorithms are required. Recently, automatic polyp detection algorithms have been proposed with various degrees of success. Though polyp detection in colonoscopy and other traditional endoscopy procedure based images is becoming a mature field, due to its unique imaging characteristics, detecting polyps automatically in VCE is a hard problem. We review different polyp detection approaches for VCE imagery and provide systematic analysis with challenges faced by standard image processing and computer vision methods.

PWE-115 Detection and Characterisation of Colorectal Polyps Using High Definition White Light and I-Scan: Evidence and Delphi Process-Based Consensus Recommendations

Introduction Electronic imaging technologies such as i-Scan, Narrow Band Imaging (NBI) and Fujinon Intelligence Colour Enhancement (FICE) are increasingly used for polyp detection and characterisation, but to date, their use is limited to expert settings. I-scan is a relatively novel technology. Insufficient literature with i-scan and the lack of RCT’s hinder its implementation in clinical practice. Our goal was to review the current literature on the clinical utility of i-scan and develop evidence-based practical recommendations. Methods We conducted a systematic review on the role of high definition white-light (HDWL) and i-Scan colonoscopy for polyp detection and characterisation. A series of evidence-based statements were developed and put through anonymous voting along the lines of a modified Delphi process. A one day consensus meeting was held (June 20, 2015, Milan). Each statement was voted until consensus (i.e >80% agreement) was achieved or rejection agreed. GRADE recommendations were assigned to the agreed statements. Results The Consensus Panel consisted of 11 international experts. In total, 11 statements were proposed, of which 9 achieved consensus: HDWL is recommended rather than standard definition (SD) for the detection and characterisation of colorectal polyps; HDWL + i-Scan improves polyp and adenoma detection rates; HDWL + i-Scan are superior to HDWL alone for the optical diagnosis of colorectal polyps; HDWL + i-Scan in expert hands meet the ASGE PIVI standards for the optical diagnosis of diminutive polyps; HDWL+i-Scan in non-expert hands do not meet the ASGE PIVI standards for the optical diagnosis of diminutive polyps; Optical diagnosis of polyps with i-Scan has a learning curve and needs systematic training; The performance of i-Scan for real time characterisation of colorectal polyps is similar to NBI & FICE. Two statements failed to achieve consensus: HDWL alone can be effective for the in-vivo characterisation of polyps in expert hands; The adenoma detection rate is comparable when using HDWL + i-scan versus chromoendoscopy. Conclusion The Consensus Panel proposes evidence-based recommendations for the detection and characterisation of colorectal polyps using high-definition white light endoscopy and i-scan, to facilitate implementation of this technology in clinical practice. Areas of uncertainty, controversy and future research needs are addressed. Disclosure of Interest None Declared

PTH-039 The First Randomised Controlled Trial of Endocuff Vision® Assisted Colonoscopy Versus Standard Colonoscopy for Polyp Detection in Bowel Cancer Screening Patients (E-Cap Study): Abstract PTH-039 Table 1

PTH-039 The First Randomised Controlled Trial of Endocuff Vision® Assisted Colonoscopy Versus Standard Colonoscopy for Polyp Detection in Bowel Cancer Screening Patients (E-Cap Study): Abstract PTH-039 Table 1

Sensitive and Noninvasive Detection of Aberrant SFRP2 and MGMT-B Methylation in Iranian Patients with Colon Polyps.

The pathogenesis of sporadic colorectal cancer (CRC) is influenced by the patient genetic background and environmental factors. Based on prior understanding, these are classified in two major pathways of genetic instability. Microsatellite instability (MSI) and CPG island methylator phenotype (CIMP) are categorized as features of the hypermethylated prototype, and chromosomal instability (CIN) is known to be indicative of the non-hypermethylated category. Secreted frizzled related protein 2 (SFRP2), APC1A in WNT signaling pathway and the DNA repair gene, O6-methylguanine-DNA methyltransferase (MGMT), are frequently hypermethylated in colorectal cancer. Detection of methylated DNA as a biomarker by easy and inexpensive methods might improve the quality of life of patients with CRC via early detection of cancer or a precancerous condition. To evaluate the rate of SFRP2 and MGMT hypermethylation in both polyp tissue and serum of patients in south Iran as compared with matched control normal population corresponding samples. Methylation-specific PCR was used to detect hypermethylation in DNA extracted from 48 polypoid tissue samples and 25 healthy individuals. Of total polyp samples, 89.5% had at least one promoter gene hypermethylation. The most frequent methylated locus was SFRP2 followed by MGMT-B (81.2 and 66.6 percent respectively). Serologic detection of hypermethylation was 95% sensitive as compared with polyp tissue. No hypermethylation was detected in normal tissue and serum and its detection in patients with polyps, especially of serrated type, was specific. Serologic investigation for detection of MGMT-B, SFRP2 hypermethylation could facilitate prioritization of high risk patients for colonoscopic polyp detection and excision.

Tu2087 The First Randomised Controlled Trial of Endocuff Vision® Assisted Colonoscopy Versus Standard Colonoscopy for Polyp Detection in Bowel Cancer Screening Patients (E-CAP study)

Introduction Up to 25% polyps are missed during colonoscopy. The Endocuff Vision® is a cap with soft flexible arms that attaches to the colonoscope tip and improves views during withdrawal. We have performed the first randomised controlled trial to identify the role of Endocuff Vision® in improving polyp detection. We aim to investigate the impact of Endocuff Vision® assisted colonoscopy on polyp detection, as compared to standard colonoscopy, in the UK Bowel Cancer Screening Programme (BCSP). Methods Single centre, parallel group, randomised controlled trial. Ethics ref: 14/SC/0207. Adopted on UKCRN portfolio (ID: 16985). Patients attending for BCSP colonoscopy were stratified based on attendance for index screening colonoscopy or for polyp surveillance. Within each stratum participants were randomised to either Standard or Endocuff assisted colonoscopy. All procedures were performed by accredited BSCP endoscopists, who have carried out > 5000 colonoscopies and have caecal intubation rates of >90%. Results 534 patients recruited from Sep 2014 to Sep 2015. 3 excluded due to new diagnosis of polyposis syndrome. 531 were included and randomised to the 2 study arms. No significant difference was seen between the 2 groups for the primary endpoint of number of polyps per patient. Secondary endpoints: No significant difference was observed between the 2 groups for adenoma detection rate (ADR) or number of adenomas per patient (Table 1). No significant adverse events were encountered during the study in either arm. The cecal intubation time was not prolonged and patients did not experience any additional discomfort due to the Endocuff Vision. Conclusion In the UK, bowel cancer screening is performed by highly experienced endoscopists. Our results suggest that in expert hands, ADR exceeds 60% even without Endocuff. In such settings, Endocuff Vision did not improve polyp detection rates (PDR) or ADR. However, it did not cause any adverse events, prolong procedure duration or cause additional discomfort. These data demonstrate the safety and feasibility of Endocuff. However, no additional gain was demonstrated in expert hands. Disclosure of Interest None Declared

Time-of-day effect and the yield of endoscopic ultrasound fine needle aspiration.

Background and Objectives:The timing of the endoscopic procedures has been recently proposed to be a factor in the quality of colonoscopic polyp detection. We aimed to investigate whether the time-of-day has an effect on the diagnostic yield and specimen adequacy of endoscopic ultrasound fine needle aspiration (EUS-FNA).Materials and Methods:The retrospective study was set in a safety net community hospital. The 212 EUS-FNAs performed at our institution between July 2011 and January 2014 were retrospectively analyzed. Pancreatic masses, pancreatic cysts, and lymphadenopathy were most common indications for EUS-FNAs. Data were collected with regard to the timing of the procedure, presence of on-site cytopathologic evaluation, the number of needle passes, diagnosis, and specimen adequacy for cytopathologic evaluation. Statistical analysis was performed using unpaired two-tailed Student's t-test.Results:There was no difference in the diagnostic yield for malignancy across all indications between the AM and PM groups. In the morning group 31/87 (36%) procedures and in the afternoon group 50/125 (40%) procedures were diagnostic for malignancy (P = 0.522). There was no difference in the specimen adequacy for cytopathologic evaluation across all indications between the AM and PM groups. In the morning group, 58/87 (67%) procedures and in the afternoon group 90/125 (72%) procedures were adequate for cytopathologic evaluation (P = 0.408). On-site cytopathologist was more available for AM than PM procedures; however, the lack of AM vs. PM difference in the yield and specimen adequacy persisted regardless of on-site cytopathologist presence.Conclusions:Time-of-day of the procedure (morning vs. afternoon) does not affect EUS-FNA diagnostic yield for malignancy or specimen adequacy for cytopathologic evaluation.

Colonoscopic Polyp Detection and Follow-up Accuracy Amongst Three Specialties

Colonoscopic Polyp Detection and Follow-up Accuracy Amongst Three Specialties

Colonoscopic Polyp Detection and Follow-up Accuracy in a Native American Population

Introduction: Analyze polyp detection rate and the accuracy of follow up recommendations in a Native American population. Methods: The Sanford health system provides medical care for much of North Dakota and central Minnesota, including a significant population with Native American ancestry. A retrospective study of screening colonoscopies performed between June 2012 and July 2013 on those of Native American ancestry analyzed polyp detection rate and post-procedure recommendations. Results: There was a 42.5% (93/233) polyp detection rate and a 29.6% (69/233) rate of inaccurate recommendations. Premature callbacks occurred in 71% (49/69) of these. This compares favorably with a 38.9% polyp detection rate and a 26.3% inaccuracy rate seen in a similar study of the general Sanford population. Conclusion: Screening colonoscopies done on Native Americans produce polyp detection rates and follow up recommendations similar to the general population.

Colonoscopic polyp detection rate is stable throughout the workday including evening colonoscopy sessions

Objective: Polyp detection rate (PDR) is an accepted measure of colonoscopy quality. Several factors may influence PDR including time of procedure and order of colonoscopy within a session. Our unit provides evening colonoscopy lists (6-9 pm). We examined whether colonoscopy performance declines in the evening. Design: Data for all National Health Service (NHS) outpatient colonoscopies performed at Norfolk and Norwich University Hospital in 2011 were examined. Timing, demographics, indication and colonoscopy findings were recorded. Statistical analysis was performed using multivariate regression. Results: Data from 2576 colonoscopies were included: 1163 (45.1%) in the morning, 1123 (43.6%) in the afternoon and 290 (11.3%) in the evening. Overall PDR was 40.80%. Males, increasing age and successful caecal intubation were all significantly associated with higher polyp detection. The indications ‘faecal occult blood screening’ (p<0.001) and ‘polyp surveillance’ (p<0.001) were strongly positively associated and ‘anaemia’ (p=0.01) was negatively associated with PDR. Following adjustment for covariates, there was no significant difference in PDR between sessions. With the morning as the reference value, the odds ratio for polyp detection in the afternoon and evening were 0.93 (95% CI = 0.72-1.18) and 1.15 (95%CI = 0.82-1.61) respectively. PDR was not affected by rank of colonoscopy within a list, sedation dose or trainee-involvement. Conclusions: Time of day did not affect polyp detection rate in clinical practice. Evening colonoscopy had equivalent efficacy and is an effective tool in meeting increasing demands for endoscopy. Standardisation was shown to have a considerable effect as demographics, indication and endoscopist varied substantially between sessions. Evening sessions were popular with a younger population

Colonoscopic polyp detection rate is stable throughout the workday including evening colonoscopy sessions

Colonoscopic polyp detection rate is stable throughout the workday including evening colonoscopy sessions

Colonoscopic polyp detection rate is stable throughout the workday including evening colonoscopy sessions.

Polyp detection rate (PDR) is an accepted measure of colonoscopy quality. Several factors may influence PDRincluding time of procedure and order of colonoscopy within a session. Our unit providesevening colonoscopy lists (6-9 pm). We examined whether colonoscopy performance declines in the evening. Data for all National Health Service (NHS) outpatient colonoscopies performed at Norfolk and Norwich University Hospital in 2011 were examined. Timing, demographics, indication and colonoscopy findings were recorded. Statistical analysis was performed using multivariate regression. Data from 2576 colonoscopies were included: 1163 (45.1%) in the morning, 1123 (43.6%) in the afternoon and 290 (11.3%) in the evening. Overall PDR was 40.80%. Males, increasing age and successful caecal intubation were all significantly associated with higher polyp detection.The indications'faecal occult blood screening' (p<0.001) and 'polyp surveillance' (p<0.001) were strongly positively associated and 'anaemia' (p=0.01) was negatively associated with PDR. Following adjustment for covariates, there was no significant difference in PDR between sessions. With the morning as the reference value, the odds ratio for polyp detection in the afternoon and evening were 0.93 (95% CI = 0.72-1.18) and 1.15 (95%CI = 0.82-1.61) respectively. PDR was not affected by rank of colonoscopy within a list, sedation dose or trainee-involvement. Time of day did not affect polyp detection rate in clinical practice. Eveningcolonoscopy had equivalent efficacy and is an effective tool in meeting increasing demands for endoscopy. Standardisation was shown to have a considerable effect as demographics, indication and endoscopist varied substantially between sessions. Evening sessions were popular with a younger population.

Detection rates of colonoscopic polyp and adenoma in average risk population of colorectal cancer and its age distribution： retrospective analysis of data from single tertiary medical center

Objective To evaluate the colonoscopic polyp detection rate （PDR） and adenoma de- tection rate （ADR） in average risk population of colorectal cancer and its age distribution, and to provide ev- idence for determining the starting age for screening colonoscopy in China. Methods Retrospective analysis was applied. Data of patients who received screening colonoseopy in the Digestive Endoscopic Center of Changhai Hospital from March 2010 to February 2013 were collected. PDR and ADR were calculated by dif- ferent genders, age groups and bowel preparation scores. Thex2 test was used to compare the PDR and ADR between different groups. Results A total of 1 928 patients received complete colonoseopies. The total PDR was 19. 55% [95% CI（ 17.78% -21.32% ） ], 23.87% and 10. 00% for men and women respectively. PDR of men was significantly higher than that of women among 40 to 70-year groups （ P 〈 0. 05 ）. The total ADR was 11.48% [95% CI（9.69% -13.28% ） ], 14. 68% and 5. 11% for men and women respectively. ADR of men was significantly higher than that of women among 40 to 70-year groups （ P 〈 O. 05 ）. The PDR of well preparation group was significantly higher than that of compromised preparation group （P 〈0. 05 ）. Conclusion Both PDR and ADR increase with age. And men have greater risk to develop polyps and adenomas than women. The quality of bowel preparation is directly related to PDR. Key words: Intestinal polyps ; Colonoscopy; Population surveillance ; Screening; Adenoma detection rate; Bowel preparation

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.

PTH-017 Strategy for Colorectal Cancer (CRC) Screening in Individuals with Significant Co-Morbid Conditions

IntroductionWith the advent of the Bowel cancer screening programme (BCSP) in the UK participants who have positive FOB tests are generally offered optical colonoscopy (OC) if considered safe, for early...

PTU-039 Colonoscopic Polyp Detection Rate is Stable Throughout the Workday including in evening Colonoscopy Sessions

IntroductionPolyp detection rate (PDR) is an accepted measure of quality of colonoscopy. Several factors may influence PDR including time of procedure and rank of colonoscopy within a session. Our unit...