***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Chromoendoscopy can accurately differentiate neoplastic from nonneoplastic polyps in the colon .  Narrow b and imaging ( NBI ) has been described as " electronic chromoendoscopy , " but it is unclear whether pit patterns seen with chromoendoscopy are identical to those with NBI . OBJECTIVE Pilot study to compare features of diminutive polyps assessed with magnification NBI and chromoendoscopy . DESIGN Prospect i ve polyp series . SETTING Single tertiary referral center in the United Kingdom . PATIENTS Twenty patients seen for routine colonoscopy .  INTERVENTION Digital images of each polyp recorded with NBI and chromoendoscopy were subsequently assessed as single images in a r and om order and as paired polyp images by experienced European- and Japanese-trained endoscopists . MAIN OUTCOME MEASUREMENTS Pit pattern ( Kudo classification ) ; vascular pattern intensity ( weak , normal , strong ) ; predicted histology ; pit pattern and vessel network clarity ( scale 1 - 3 , 1 poor , 3 excellent ) . RESULTS A total of 33 polyps < or=6 mm were assessed . Chromoendoscopic and NBI pit patterns were different for 12 and 20 of 33 polyps ( Japanese and European , respectively ) , combined kappa 0.23 , P < .001 compared with published intraobsever variation . Sensitivity , specificity , and accuracy for neoplasia were comparable for chromoendoscopic and NBI pit patterns and vascular pattern intensity for both observers . Vessel network clarity was better with NBI , P < .001 ( both ) , as was pit pattern clarity , P = .04 ( European ) . LIMITATIONS Small sample size ; pilot study . CONCLUSIONS Pit patterns were not always identical with NBI and chromoendoscopy . The Kudo classification may need to be modified and revali date d before it can be used with confidence with NBI .  Vascular pattern intensity , a simple color change , appears as accurate as pit pattern Objective Cap-assisted colonoscopy ( CAC ) uses a small plastic transparent cap attached to the tip of the colonoscope that can depress and flatten colonic folds and thus improve visualisation of their proximal aspects . The aim of this study was to compare CAC with st and ard colonoscopy ( SC ; high-definition white light ) for adenoma detection rates . Design This is a prospect i ve r and omised controlled trial . Setting The study was performed in a tertiary-care Veterans Affairs Medical Center in the USA . Patients Subjects undergoing screening or surveillance colonoscopy were enrolled . Interventions Subjects were r and omised to undergo either CAC or SC . Main outcome measures The outcome measures were the proportion of subjects with at least one adenoma , the number of adenomas detected per subject , insertion time , caecal intubation rates and complications . Results 420 subjects were enrolled and included in the study ( 210 in each group ) . The proportion of subjects with at least one adenoma was higher with CAC compared to SC ( 69 % vs 56 % , p=0.009 ) . CAC also detected a higher number of adenomas per subject ( 2.3 vs 1.4 , p<0.001 ) . The caecal intubation time was shorter with CAC ( 3.29 min vs 3.98 min , p<0.001 ) . The caecal intubation rates were similar in the two groups ( 99 % vs 98 % , p=0.37 ) . There were no complications associated with CAC or SC . Conclusions CAC detected a 13 % higher number of subjects with at least one adenoma and 59 % higher adenomas per subject . CAC is a safe , effective and practical means to improve adenoma detection rates . Clinical Trial Registration NCT 01211132 Objectives Colonoscopy is central to colorectal cancer ( CRC ) screening . Success of CRC screening is dependent on colonoscopy quality . The NHS Bowel Cancer Screening Programme ( BCSP ) offers biennial faecal occult blood ( FOB ) testing to 60–74 year olds and colonoscopy to those with positive FOB tests . All colonoscopists in the screening programme are required to meet predetermined st and ards before starting screening and are subject to ongoing quality assurance . In this study , the authors examine the quality of  colonoscopy  in the NHS BCSP and describe new and established measures to assess and maintain quality . Design The NHS BCSP data base collects detailed data on all screening colonoscopies . Prospect ively collected data from the first 3 years of the programme ( August 2006 to August 2009 ) were analysed . Colonoscopy quality indicators ( adenoma detection rate ( ADR ) , polyp detection rate , colonoscopy withdrawal time , caecal intubation rate , rectal retroversion rate , polyp retrieval rate , mean sedation doses , patient comfort scores , bowel preparation quality and adverse event incidence ) were calculated along with measures of total adenoma detection . Results 2 269 983 individuals returned FOB tests leading to 36 460 colonoscopies .  Mean unadjusted caecal intubation rate was 95.2 % , and mean withdrawal time for normal procedures was 9.2 min . The mean ADR per colonoscopist was 46.5 % . The mean number of adenomas per procedure ( MAP ) was 0.91 ; the mean number of adenomas per positive procedure ( MAP+ ) was 1.94 . Perforation occurred after 0.09 % of procedures . There were no procedure-related deaths . Conclusions The NHS BCSP provides high- quality colonoscopy , as demonstrated by high caecal intubation rate , ADR and comfort scores , and low adverse event rates . Quality is achieved by ensuring BCSP colonoscopists meet a high st and ard before starting screening and through ongoing quality assurance . Measuring total adenoma detection ( MAP and MAP+ ) as adjuncts to ADR may further enhance quality assurance Background Diminutive ( ≤5 mm ) colorectal polyps are common , and overwhelmingly benign . Routinely , after polypectomy , they are examined pathologically to determine the surveillance intervals . Advances in equipment and techniques , such as narrow-b and imaging ( NBI ) colonoscopy , now permit reliable real-time optical diagnosis . Methods We conducted a r and omised single-masked study involving three institutions to determine whether optical diagnosis of diminutive colorectal polyps meets clinical practice st and ards and reduces the need for histopathology . We r and omly assigned eligible patients undergoing routine high-definition colonoscopy  to optical diagnosis using near focus versus st and ard view , using computer-generated block sequence . By vali date d criteria , we rendered an optical diagnosis and a confidence level ( high vs low ) for all polyps , using NBI . Our primary endpoint was the number of accurate high-confidence optical diagnoses compared with central blinded pathology in the two groups . We analysed data using intention to treat . Findings We enrolled 558 subjects , and r and omly assigned 281 to near focus and 277 to st and ard view optical diagnosis . We detected 1309 predominantly diminutive ( 74.5 % ) and neoplastic ( 60.0 % ) polyps . Endoscopists were significantly more likely , OR 2.2 ( 95 % CI 1.6 to 3.0 , p<0.0001 ) , to make a high-confidence optical diagnosis with near focus ( 85.1 % ) than st and ard ( 72.6 % ) view . High-confidence diagnoses had 96.4 % and 92.0 % negative predictive value , respectively . Of all polyps , 75.3 % ( 95 % CI71.3 % to 78.9 % ) had a high-confidence accurate prediction using near focus , compared with 63.1 % ( 95 % CI 58.5 % to 67.6 % ) using st and ard view . Optical versus histopathological diagnosis showed excellent agreement between the surveillance intervals , 93.5 % in near focus and 92.2 % in st and ard view . The median diagnosis time was 14 s. Conclusions Real-time optical diagnosis using NBI colonoscopy may replace the pathology diagnosis for the majority of diminutive colorectal polyps . Using colonoscopy with near focus view increases the confidence level of the optical diagnosis . Optical diagnosis would be a paradigm shift in clinical practice of colonoscopy for colorectal cancer screening . Trial registration number Clinical Trials.gov Identifier : NCT01288833 BACKGROUND The EPKi system ( Pentax , Japan ) enables resolution above HDTV . Aim of the study was to test the efficacy of HD+ alone and with the new post-processing digital filter i-Scan or chromoendoscopy ( Methylene blue 0.1 % ) in screening for colorectal cancer . We focused on lesions less than 5 mm as a surrogate marker for the optical possibilities of the EPKi system . METHODS The last 30 cm of the colon in a screening population were inspected with HD+ alone , in combination with i-Scan ( 2:1 r and omisation ) and subsequently with chromoendoscopy . All lesions were characterized and targeted biopsies were performed . RESULTS i-Scan  augmented in 69 patients the identification of lesions from 176 to 335 ( p<0.001 ) and chromoendoscopy to 646 ( p<0.001 ) . The additional lesions were mainly flat ( type IIb , 74 % ) , which were only recognized using i-Scan or chromoendoscopy . The amount of neoplasias was not significantly different ( HD+ : 5 , i-Scan : 11 , Chromoendoscopy : 11 ) , but all could correctly be predicted using i-Scan or chromoendoscopy . CONCLUSIONS HD+ colonoscopy with and without i-Scan unmask a plethora of small lesions but chromoendoscopy can even advance the number . However , i-Scan was able to predict neoplasia as precisely as chromoendoscopy and might shortly replace chromoendoscopy as a more time efficient tool BACKGROUND AND STUDY AIMS Narrow-b and imaging ( NBI ) has shown promising results in discriminating adenomatous from non-adenomatous colonic polyps . In patients with small polyps ( < 10 mm ) , the application of NBI within a " resect and discard " strategy , might allow post-polypectomy surveillance intervals to be determined independently from histopathology . The aim of the present study was to assess the feasibility and safety of this approach in routine clinical practice . PATIENTS AND METHODS Consecutive colonoscopy out patients with one or more polyps smaller than 10 mm were prospect ively included . Each polyp was categorized by the endoscopist as adenoma or non-adenoma according to simplified NBI criteria , and future post-polypectomy surveillance interval was assigned accordingly . Following histopathology ,  post-polypectomy surveillance interval was subsequently re-assigned , and the accordance between endoscopy- and histology-directed surveillance  strategies was calculated . RESULTS Among 942 colonoscopy patients , 286 ( 30.4 % ) with only small polyps were included . In total , 511 small polyps were evaluated ; 350 ( 68.5 % ) were adenomas and 18 of these ( 5.1 % ) had histologic features of advanced neoplasia . For the in vivo diagnosis of adenoma , NBI sensitivity , specificity , accuracy , and positive and negative likelihood ratios were 94.9 % , 65.8 % , 85.7 % , 2.80 , and 0.08 , respectively . The endoscopy-directed surveillance strategy was in accordance with the  histology-directed strategy in 237 of 286 patients ( 82.9 % ) . In 9.8 % and 7.3 % patients , the endoscopy-directed approach would have result ed in early and delayed surveillance , respectively . CONCLUSIONS The resect and discard strategy seems to be a viable , safe , and cost-effective approach for the management of patients with small polyps . However , caution in the application of the strategy should be advocated for patients with polyps 6 - 9 mm in size and those with right-sided lesions , due to their malignant potential . The study was registered on Clinical trials.gov ( NCT01462123 ) OBJECTIVES : St and ard white light colonoscopy has limited ability to differentiate between polyp types ( adenomatous vs. hyperplastic ) . Narrow b and imaging ( NBI ) highlights the superficial mucosal/vascular patterns on polyps and may facilitate real-time characterization of polyp histology . The aim of this study was to prospect ively evaluate and compare the diagnostic characteristics of high-definition white light colonoscopy ( HDWL ) and NBI without magnification in the real-time prediction of polyp histology ( adenomatous vs. hyperplastic ) by evaluating the surface mucosal and vascular patterns . METHODS : We conducted a prospect i ve comparative study in a tertiary referral center . A total of 100 patients referred for screening or surveillance colonoscopy were prospect ively enrolled and underwent colonoscopy using a high-definition colonoscope with NBI capability . Every polyp detected was initially evaluated with HDWL followed by NBI for the presence of surface mucosal/vascular patterns . Based on these patterns , polyp histology was predicted by both modalities . The main outcome measurements were : ( i ) diagnostic characteristics of HDWL and NBI in predicting polyp histology and ( ii ) impact of polyp size and learning effect ( first half of study vs. second half ) on the ability of NBI to predict adenomas . RESULTS : A total of 236 polyps were detected in 100 patients —143 adenomas ,  
    Output:
    
VCE technologies , using HD systems without magnification , could potentially be used for the real-time assessment of diminutive colorectal polyps , if endoscopists have adequate experience and training .