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BACKGROUND AND AIM We aimed to investigate whether linked color imaging (LCI) improves endoscopic visibility of early gastric cancers (EGC) after Helicobacter pylori eradication, which are often difficult to detect, and reduces the miss rate when compared with white-light imaging (WLI). METHODS The visibility study used two images, one each with WLI and LCI, from 84 consecutive EGC after H. pylori eradication. Endoscopic visibility was evaluated using a visibility score and color difference (CD) value. To analyze miss rates, we studied a library of recorded videos using both WLI and LCI for 70 other consecutive patients after H. pylori eradication, among whom 19 had EGC. Endoscopic screening was done using the same protocol to map the entire stomach. Six endoscopists reviewed the videos in a randomized order. Miss rates of EGC were compared among the modalities. RESULTS Mean [(±standard deviation) visibility scores with LCI were significantly higher than those with WLI (3.19 ± 0.84 vs 2.52 ± 0.98, P

BACKGROUND AND AIM To assess the visibility of colorectal lesions using blue laser imaging (BLI)-bright and linked-color imaging (LCI) with an eye-tracking system. METHODS Eleven endoscopists evaluated 90 images of 30 colorectal lesions. The lesions were randomly selected. Three images of each lesion comprised white light imaging (WLI), BLI-bright, and LCI in the same position. Participants gazed at the images, and their eye movements were tracked by the eye tracker. We analyzed whether the participants could detect the lesion and how long they took to detect the lesion. We assessed the miss rate and detection time among the imaging modalities. RESULTS One endoscopist was excluded, and 10 endoscopists were assessed. Overall, 12.6% of lesions were missed with WLI, 6.0% with BLI-bright, and 4.3% with LCI; the miss rate of BLI-bright and LCI was significantly lower than that of WLI (P

This article shows how Bayesian thinking can help legal fact-finders to avoid some common fallacies and biases in the evaluation of legal evidence (false dichotomy, dependence neglect, and miss rate neglect).

Background and aim Right colon polyps can especially be overlooked when they are located on the backs of haustral folds. Previous studies have reported that repeated forward-view examinations in the right colon were effective in reducing adenoma miss rates. The aim of this study was to clarify the impact of retroflexion in the right colon after repeated forward-view examinations. Methods This multicenter, prospective, observational study was conducted at three institutions in Kumamoto, Japan, between February 2014 and December 2015. Subjects who were over 40 years old and scheduled for colonoscopy were recruited. For the forward view, after cecal intubation, the colonoscope was withdrawn to the hepatic flexure. The colonoscope was sequentially reinserted to the cecum and then withdrawn to the hepatic flexure. For the retroflexion view (RV), the colonoscope was reinserted to the cecum, retroflexed, and then withdrawn to the hepatic flexure. All polyps were resected at the time of detection. The primary outcome of this study was the adenoma miss rate for the repeated forward-view examinations. Results Of the 777 enrolled participants, retroflexion was successful in 730 (94.0%). The repeated forward-view withdrawal technique detected 291 adenomas, while the third withdrawal in the RV detected 53. The adenoma miss rate for the repeated forward-view withdrawal was 15.4%. No severe adverse events occurred during retroflexion. Conclusion Because adenomas located on potential blind spots can be missed when only using forward-view examinations, retroflexion in the right colon after repeated forward-view examinations might improve colonoscopy detection rates.

AIM In the UK Bowel Scope Screening Programme (BSSP), patients progress to colonoscopy based on high-risk features on flexible sigmoidoscopy (FS). We aim to assess the practice of colonoscopy conversion and predictors of detection of additional adenomas on colonoscopy. METHOD The Bowel Cancer Screening database was interrogated and collated with endoscopic and histological findings from patients undergoing colonoscopy following FS between August 2013 and August 2016. Multivariate analysis was performed to identify predictors of new adenomas. RESULTS FS was performed on 11 711 patients, with an adenoma detection rate (ADR) of 8.5% and conversion to colonoscopy in 421 (3.6%). The additional ADR at colonoscopy was 35.2%, with one additional malignant diagnosis (0.26%). The adenoma miss rate was 3.6%. On multivariate analysis, a polyp ≥ 10 mm was the only high-risk indication associated with additional ADR at colonoscopy (OR 3.68, 95% CI 1.51-3.65, P

With software-defined networking (SDN) becoming the leading technology for large-scale networks, it is definitely expected that SDN will suffer various types of distributed denial-of-service (DDoS) attacks because of its centralized control logic. However, almost all of existing works concentrate on the controller overloading DDoS attacks, while vulnerabilities exposed by data plane of SDN for DDoS attacks are largely ignored. In this paper, we firstly investigate a flow rule flooding DDoS attack. By thoroughly analyzing the flow table size and miss rate, we find that attackers are able to inflict significant performance degradation over the system with limited volume of attack resource. We then prove that it is possible for attackers to maximize the performance degradation and minimize the attack rate at the same time. Besides the flooding DDoS attack, we also study a novel DDoS attack targeting data plane of SDN. By utilizing the entry lifetime management mechanism of flow tables, this attack almost never exhibits an intensive controller access behavior. It flies under the radar by inflicting non-notable performance impact on the system, while it creates heavy long-term financial burden on the target application. Finally, we present a potential countermeasure for this stealthy DDoS attack. Through extensive experiments, we conclude that DDoS attacks targeting data plane are possible. Copyright © 2016 John Wiley & Sons, Ltd.

BACKGROUND AND AIM Colonoscopy is sensitive at detecting large polyps; however, a significant polyp miss rate is still recognized. Indicators such as the adenoma detection rate (ADR) and, more recently, the adenoma per colonoscopy rate (APC) are increasingly used to ensure quality in colonoscopy. We carried out a prospective, randomized, controlled study evaluating improvement in adenoma detection between wide-screen, high-definition (WSHD) monitors compared to standard monitors (SD). METHODS Patients undergoing screening or surveillance colonoscopy were randomized to a WSHD room or SD. Polyp size, location, shape, and histology were recorded. Right-sided polyps were considered to be those proximal to the splenic flexure. RESULTS A total of 152 patients were enrolled in the study, with 78 (51.3%) and 74 (48.7%) enrolled in the WSHD and SD groups, respectively. A 10% absolute difference in favor of the WSHD group was noted for the ADR (41% vs 31% patients); however, the difference was statistically not significant. In the WSHD and SD groups, APC of 0.9 ± 1.4 versus 0.7 ± 1.4 (P = 0.49) were noted, respectively. For polyps

Early detection and removal of adenomatous polyps reduces colorectal cancer death. However, many studies have reported that up to 20% of adenomas can be missed during colonoscopy. To improve visualization and reduce the blind spot of the colonic mucosa for an increase in the adenoma detection rate, many endoscopic techniques and technologies have been developed. The benefit of the high-definition endoscope for improving adenoma and polyp detection is marginal. Wide-angle colonoscope has failed to improve adenoma detection compared to standard colonoscopy. Although the cap-assisted colonoscope can reduce cecal intubation times, it does not seem to improve adenoma and polyp detection. The diagnostic accuracy of the colon capsule endoscope is low compared to the conventional colonoscope. Third Eye(®) retroscope(®) , which provides additional retrograde viewing, has revealed significant improvement in adenoma and polyp detection compared to standard colonoscopy. However, this device increases procedural times. Recently developed full-spectrum endoscopy colonoscope and extra-wide-angle-view colonoscope have demonstrated a significantly lower miss rate of polyps. However, clinical trials are mandatory to determine the efficacy of these novel technologies for cancer screening. In addition, education and training for these novel techniques and technologies should seriously be considered to improve adenoma and polyp detection.

Background and Aim Capsule endoscopy (CE) has a high sensitivity for diagnosing small bowel Crohn's disease, but video analysis is time-consuming. The quick view (qv) function is an effective tool to reduce time consumption. The aim of this study was to determine the rate of missed small bowel ulcerations with qv-CE compared with standard view and the diagnostic accuracy of qv-CE in suspected Crohn's disease. Methods This study consisted of two parts: (i) 12 small bowel segments with Crohn's disease of varying severity were selected for a detailed analysis of the number and type of lesions visualized with CE and qv-CE, and (ii) a blinded study of the diagnostic accuracy of qv-CE including 40 patients with suspected Crohn's disease. Ileocolonoscopy and CE served as gold standard. Results Part 1: CE visualized 171 ulcerations compared with 102 detected with qv-CE (miss rate 40%, P = 0.02). Part 2: qv-CE identified 15 of 16 patients with small bowel Crohn's disease corresponding to a 94% sensitivity, and overall, 39 out of 40 patients were classified correct (diagnostic accuracy 98%). Qv-CE was false negative in one patient because of a leap of 3 min and 20 s in the terminal ileum. Reading times varied from 5 to 18 min (median 10). Conclusion Despite a significant number of missed lesions, qv-CE is a safe and time-reducing method for diagnosing small bowel Crohn's disease. To avoid false negative cases, we recommend viewing the terminal ileum in standard view.

This letter presents a very simple yet very effective solution for fast reference frame (RF) selection in H.264/AVC. By efficiently making use of the correlation between the best RF indices in various inter modes, the proposed method significantly reduces the number of RFs to be examined at the expense of a very small miss rate. Simulation results show that the proposed method not only improves upon the coding performance of conventional methods but also reduces the encoding time significantly.

Aim To determine the sensitivity of computed tomographic colonography (CTC) in the detection of colorectal cancer in our population and evaluate the reasons why these lesions may be missed on CTC. Methods All patients who underwent CTC in the 65-month period from 1 January 2004 to 1 July 2009 were included in the analysis. Demographic data and CTC findings were recorded, according to the CT Colonography Reporting and Data System. Data were cross-matched with the National Cancer Registry results for colorectal cancer cases between 1 January 2004 and 1 October 2009, 3 months longer to include any delayed diagnoses. Results There were 2026 consecutive CTC patients, comprising 52.6% female, average age of 60 years; range 19–87. Approximately 84% were symptomatic. There were 45 confirmed colorectal cancers among this patient group in the National Cancer Registry during the relevant time period compared with 43 suspected cancers on CTC, giving a miss rate of 2 of 45, or 4.4%. Conclusion The sensitivity of 95% for CTC in the detection of colorectal cancer compares favourably with the published national and international data.

Introduction The aim of colonoscopy is to examine the colon completely and meticulously looking for malignant and pre-malignant lesions (adenomas). The measure for completeness is the caecal intubation rate (CIR) and for thoroughness the adenoma detection rate (ADR). National Standards (NS) are ≥90% and ≥10% respectively. 1 Variability in CIR, ADR and thusly quality, have been shown but comparison between individuals and units is difficult. 2 3 We aimed to use graphical representation to assess colonoscopy performance in the North East of England. Methods Data on colonoscopy performance and sedation use were collected over 3 months from 12 units. Colonoscopies performed by screening colonoscopists were included in the global CIR only. Funnel plots with upper and lower 95% confidence limits (CL) for CIR and ADR were created using the binomial probability distributions for inferences about a single proportion. Results CIR was 92.5% (n=5720) and ADR 15.9% (n=4748). All units and 128 (99.2%) colonoscopists were above the lower limit for CIR. All units achieved the ADR standard with 10 above the upper limit. Ninety-nine (76.7%) colonoscopists were above 10%, 16 (12.4%) above the upper limit and 7 (5.4%) below the lower limit (Abstract PWE-189 figure 1). Median medication doses were: 2.2 mg midazolam, 29.4 mg pethidine, and 83.3 mg fentanyl. 15.1% of colonoscopies were unsedated. Complications were bleeding (0.10%) and perforation (0.02%). There was 1 death possibly related to bowel preparation. Conclusion Results indicate colonoscopies are performed safely and to a high standard. Funnel plots can highlight variability and areas for improvement. Analyses of ADR presented graphically around the global mean suggest that the NS should be reset at 15%. Competing interests None declared. References 1. The Joint Advisory Group for Gastrointestinal Endoscopy . Guidance for colonoscopy certification and continued practice. Dr Colin Rees and Dr John Painter. 2006. http://www.thejag.org.uk 2. Bowles CJ , Leicester R, Romaya C. A prospective study of colonoscopy practice in the UK today: are we adequately prepared for the national colorectal cancer screening tomorrow? Gut 2004; 53 :277–83. 3. van Rijn JC , Reitsma JB, Stoker J, et al. Polyp miss rate determined by tandem colonoscopy: a systematic review. Am J Gastroenterol 2006; 101 :343–50.

Objective Quality assurance in colonoscopy is important, and subjective assessment of completion based on endoscopic signs can be inaccurate leading to missed lesions. We aimed to determine the technique of endomucosal clips with follow-up X-rays in objectively documenting completion and correlation with pathology miss rates. Method A total of 82 patients undergoing colonoscopy by trained colonoscopists had an endomucosal clip applied to the most proximal bowel reached. A plain abdominal X-ray was performed while there was still a pneumocolon, and the clip position was assessed by a blinded radiologist to determine objective completion rates. Repeat colonoscopies were performed in patients with incomplete procedures. Pathology and endoscopy database were also reviewed to identify missed lesions at a median follow-up of 6 years. These were correlated with colonoscopy completions. Results The clip was found in caecum of 76 (93%), ascending-colon in three (3.6%), hepatic flexure in one (1.2%) and splenic flexure in two (2.4%) patients. The endoscopist opinion was incorrect in six incomplete colonoscopies. A total of 33 patients underwent repeat colonoscopies over the median 6-year follow-up. Three adenomas and one carcinoma were missed in the incomplete group and were subsequently picked up in repeat endoscopies. Only one adenoma was truly missed in complete colonoscopies, providing an overall miss rate of 1.3%. Conclusion Use of endomucosal clips with follow-on abdominal X-ray is a safe and effective method of determining completion of colonoscopy. This technique is also an excellent objective measure of quality assurance of completion and miss rates in colonoscopy, especially when combined with an audit to determine the missed lesions at two years postprocedure.

Packet networks are currently enabling the integration of traffic with a wide range of characteristics that extend from video traffic with stringent quality of service (QoS) requirements to the best-effort traffic requiring no guarantees. QoS guarantees can be provided in conventional packet networks by the use of proper packet-scheduling algorithms. As a computer revolution, many scheduling algorithms have been proposed to provide different schemes of QoS guarantees, with Earliest Deadline First (EDF) as the most popular one. With EDF scheduling, all flows receive the same miss rate regardless of their traffic characteristics and deadlines. This makes the standard EDF algorithm unsuitable for situations in which the different flows have different miss rate requirements since in order to meet all miss rate requirements it is necessary to limit admissions so as to satisfy the flow with the most stringent miss rate requirements. In this paper, we propose a new priority assignment scheduling algorithm, Hierarchal Diff-EDF (Differentiate Earliest Deadline First), which can meet the real-time needs of these applications while continuing to provide best-effort service to non-real time traffic. The Hierarchal Diff-EDF features a feedback control mechanism that detects overload conditions and modifies packet priority assignments accordingly.

Background: The incidence rate after a colonoscopic polypectomy includes the true incidence rate of new polyp formation and miss rate of polyps at the initial colonoscopy. It is therefore important to assess accurate incidence rates of polyps as well as those of missing polyps with colocoscopy. Methods: Six hundred and eighty-eight patients who underwent total colonoscopy twice within 30 days were investigated to determine the miss rates of neoplastic polyps under colonoscopy. The cumulative incidence rates of neoplasm were evaluated by the Kaplan-Meier method in another series of investigations on 864 patients who underwent surveillance total colonoscopy over 31 days. Results: In 157 (22.8%) patients out of 688, 200 neoplastic lesions (all adenomas) were missed during the first examination. The miss rate was 16% for adenomas ≤ 5 mm and 2% for adenomas > 10 mm. The miss rates of patients with 0, 1, 2, or > 2 neoplastic polyps on the first examination was 5.3%, 19.6%, 23.5% and 35.5%, respectively. One year cumulative incidence rates of patients with 1, 2, or > 2 neoplastic polyps on the first examination were 18.4%, 21.1% and 34.2%, respectively. Conclusion: Detection of multiple neoplasms on index colonoscopy predicts a high miss rate and cumulative incidence rate on surveillance colonoscopy. A substantial proportion of neoplasms detected at nearly 1-year postpolypectomy surveillance colonoscopy were missed at the initial total colonoscopy.

Aim This study examined the relevance of using a two-sample quantitative immunochemical faecal occult blood test (FIT) at a high cut-off stringency by the first population-based colorectal cancer (CRC) pilot screening programme in Ireland. Method Approximately 10 000 individuals between the ages of 50 and 74 years were invited to perform two consecutive FITs. These were analysed in tandem using the OC Sensor and participants with at least one positive result with a haemoglobin cut-off for positivity at 100 ng/ml were offered colonoscopy. Results A total of 5023 (52%) [2177 (43%) male, 2846 (57%) female] individuals with a median age of 64 years participated. At least one positive FIT was detected from 514 (10%) individuals. From the 419 (82%) patients who proceeded to colonoscopy 17 (4%) had CRC and 132 (33%) had an advanced adenoma. The detection rate for these screen-relevant lesions was 3% (95% CI 2.5–3.5) and the FIT-positive colonoscopy detection rate was 36% (95% CI 31–40). The number needed to undergo colonoscopy to find an advanced lesion was 2.8. The two-test system detected four (23.5%) additional patients with CRC and 37 (28%) with an advanced adenoma compared with a single test. Conclusion The CRC miss rate estimated for a single test (23.5%) was unacceptably high when the goal was to maximize the discovery of advanced lesions in the initial screening round. We conclude that the two-test protocol at a high cut-off threshold is suitable for optimizing FIT screening in Ireland.