Randomized Trial Comparing Left Colon Mucus Production Using Water vs Saline During Water Exchange Colonoscopy.

INTRODUCTION: Water-assisted colonoscopy increases left colon mucus production; however, the effect of saline on mucus production is unclear. We tested the hypothesis that saline infusion may reduce mucus production in a dose-related manner. METHODS: In a randomized trial, patients were assigned to colonoscopy with CO 2 insufflation, water exchange (WE) with warm water, 25% saline, or 50% saline. The primary outcome was the Left Colon Mucus Scale (LCMS) score (5-point scale). Blood electrolytes were measured before and after saline infusion. RESULTS: A total of 296 patients with similar baseline demographics were included. The mean LCMS score for WE with water was significantly higher than that for WE with saline and CO 2 (1.4 ± 0.8 [WE water] vs 0.7 ± 0.6 [WE 25% saline] vs 0.5 ± 0.5 [WE 50% saline] vs 0.2 ± 0.4 [CO 2 ]; overall P < 0.0001), with no significant difference between the 25% and 50% saline groups. The left colon adenoma detection rate (ADR) was highest in the 50% saline group, followed by the 25% saline and the water groups (25.0% vs 18.7% vs 13.3%), but the difference was not significant. Logistic regression showed water infusion as the only predictor of moderate mucus production (odds ratio 33.3, 95% confidence interval 7.2-153.2). No acute electrolyte abnormalities were documented indicating a safe modification. DISCUSSION: The use of 25% and 50% saline significantly inhibited mucus production and numerically increased ADR in the left colon. Evaluation of the impact of mucus inhibition by saline on ADR may refine the outcomes of WE.

A Novel Computer-Aided Detection/Diagnosis System for Detection and Classification of Polyps in Colonoscopy.

Using a deep learning algorithm in the development of a computer-aided system for colon polyp detection is effective in reducing the miss rate. This study aimed to develop a system for colon polyp detection and classification. We used a data augmentation technique and conditional GAN to generate polyp images for YOLO training to improve the polyp detection ability. After testing the model five times, a model with 300 GANs (GAN 300) achieved the highest average precision (AP) of 54.60% for SSA and 75.41% for TA. These results were better than those of the data augmentation method, which showed AP of 53.56% for SSA and 72.55% for TA. The AP, mAP, and IoU for the 300 GAN model for the HP were 80.97%, 70.07%, and 57.24%, and the data increased in comparison with the data augmentation technique by 76.98%, 67.70%, and 55.26%, respectively. We also used Gaussian blurring to simulate the blurred images during colonoscopy and then applied DeblurGAN-v2 to deblur the images. Further, we trained the dataset using YOLO to classify polyps. After using DeblurGAN-v2, the mAP increased from 25.64% to 30.74%. This method effectively improved the accuracy of polyp detection and classification.

Computer-Aided Image Enhanced Endoscopy Automated System to Boost Polyp and Adenoma Detection Accuracy.

Colonoscopy is the gold standard to detect colon polyps prematurely. Early detection, characterization and resection of polyps decrease colon cancer incidence. Colon polyp missing rate remains high despite novel methods development. Narrowed-band imaging (NBI) is one of the image enhance techniques used to boost polyp detection and characterization, which uses special filters to enhance the contrast of the mucosa surface and vascular pattern of the polyp. However, the single-button-activated system is not convenient for a full-time colonoscopy operation. We selected three methods to simulate the NBI system: Color Transfer with Mean Shift (CTMS), Multi-scale Retinex with Color Restoration (MSRCR), and Gamma and Sigmoid Conversions (GSC). The results show that the classification accuracy using the original images is the lowest. All color transfer methods outperform the original images approach. Our results verified that the color transfer has a positive impact on the polyp identification and classification task. Combined analysis results of the mAP and the accuracy show an excellent performance of the MSRCR method.

Polyp detection and false-positive rates by computer-aided analysis of withdrawal-phase videos of colonoscopy of the right-sided colon segment in a randomized controlled trial comparing water exchange and air insufflation.

BACKGROUND AND AIMS: Water exchange (WE) improves lesion detection but misses polyps because of human limitations. Computer-aided detection (CADe) identifies additional polyps overlooked by the colonoscopist. Additional polyp detection rate (APDR) is the proportion of patients with at least 1 additional polyp detected by CADe. The number of false positives (because of feces and air bubble) per colonoscopy (FPPC) is a major CADe limitation, which might be reduced by salvage cleaning with WE. We compared the APDR and FPPC by CADe between videos of WE and air insufflation in the right-sided colon. METHODS: CADe used a convolutional neural network with transfer learning. We edited and coded withdrawal-phase videos in a randomized controlled trial that compared right-sided colon findings between air insufflation and WE. Two experienced blinded endoscopists analyzed the CADe-overlaid videos and identified additional polyps by consensus. An artifact triggered by CADe but not considered a polyp by the reviewers was defined as a false positive. The primary outcome was APDR. RESULTS: Two hundred forty-five coded videos of colonoscopies inserted with WE (n = 123) and air insufflation (n = 122) methods were analyzed. The APDR in the WE group was significantly higher (37 [30.1%] vs 15 [12.3%], P = .001). The mean [standard deviation] FPPC related to feces (1.78 [1.67] vs 2.09 [2.09], P = .007) and bubbles (.53 [.89] vs 1.25 [2.45], P = .001) in the WE group were significantly lower. CONCLUSIONS: CADe showed significantly higher APDR and lower number of FPPC related to feces and bubbles in the WE group. The results support the hypothesis that the strengths of CADe and WE complement the weaknesses of each other in optimizing polyp detection.

Computer-Aided Colon Polyp Detection on High Resolution Colonoscopy Using Transfer Learning Techniques.

Colonoscopies reduce the incidence of colorectal cancer through early recognition and resecting of the colon polyps. However, the colon polyp miss detection rate is as high as 26% in conventional colonoscopy. The search for methods to decrease the polyp miss rate is nowadays a paramount task. A number of algorithms or systems have been developed to enhance polyp detection, but few are suitable for real-time detection or classification due to their limited computational ability. Recent studies indicate that the automated colon polyp detection system is developing at an astonishing speed. Real-time detection with classification is still a yet to be explored field. Newer image pattern recognition algorithms with convolutional neuro-network (CNN) transfer learning has shed light on this topic. We proposed a study using real-time colonoscopies with the CNN transfer learning approach. Several multi-class classifiers were trained and mAP ranged from 38% to 49%. Based on an Inception v2 model, a detector adopting a Faster R-CNN was trained. The mAP of the detector was 77%, which was an improvement of 35% compared to the same type of multi-class classifier. Therefore, our results indicated that the polyp detection model could attain a high accuracy, but the polyp type classification still leaves room for improvement.

Computer-Aided Detection False Positives in Colonoscopy.

Randomized control trials and meta-analyses comparing colonoscopies with and without computer-aided detection (CADe) assistance showed significant increases in adenoma detection rates (ADRs) with CADe. A major limitation of CADe is its false positives (FPs), ranked 3rd in importance among 59 research questions in a modified Delphi consensus review. The definition of FPs varies. One commonly used definition defines an FP as an activation of the CADe system, irrespective of the number of frames or duration of time, not due to any polypoid or nonpolypoid lesions. Although only 0.07 to 0.2 FPs were observed per colonoscopy, video analysis studies using FPs as the primary outcome showed much higher numbers of 26 to 27 per colonoscopy. Most FPs were of short duration (91% < 0.5 s). A higher number of FPs was also associated with suboptimal bowel preparation. The appearance of FPs can lead to user fatigue. The polypectomy of FPs results in increased procedure time and added use of resources. Re-training the CADe algorithms is one way to reduce FPs but is not practical in the clinical setting during colonoscopy. Water exchange (WE) is an emerging method that the colonoscopist can use to provide salvage cleaning during insertion. We discuss the potential of WE for reducing FPs as well as the augmentation of ADRs through CADe.

A review of water exchange and artificial intelligence in improving adenoma detection.

Water exchange (WE) and artificial intelligence (AI) have made critical advances during the past decade. WE significantly increases adenoma detection and AI holds the potential to help endoscopists detect more polyps and adenomas. We performed an electronic literature search on PubMed using the following keywords: water-assisted and water exchange colonoscopy, adenoma and polyp detection, artificial intelligence, deep learning, neural networks, and computer-aided colonoscopy. We reviewed relevant articles published in English from 2010 to May 2020. Additional articles were searched manually from the reference lists of the publications reviewed. We discussed recent advances in both WE and AI, including their advantages and limitations. AI may mitigate operator-dependent factors that limit the potential of WE. By increasing bowel cleanliness and improving visualization, WE may provide the platform to optimize the performance of AI for colonoscopies. The strengths of WE and AI may complement each other in spite of their weaknesses to maximize adenoma detection.

A trade-off dual-factor model to investigate discontinuous intention of health app users: From the perspective of information disclosure.

Numerous mobile apps have been developed for making our lives more convenient and improving our quality of life. Health apps are among them. These types of apps are designed to help users for recording their health-related behaviors and to give advice about improving users' physical conditions. However, users frequently do not continue to use these health apps. As a result, the companies of health apps have paid the development cost but cannot get back the benefit from the apps they launch. To find out the reason, this study conducts an empirical investigation and develops a trade-off dual-factor model to dissect the reason why users discontinue use of health apps. The research model is based on the perspectives of information disclosure and expectation-confirmation theory. Users may worry about the disclosure of individual health privacy; however, on the other hand, they enjoy the functions of health apps, proffering various kinds of health-related assistance. The decision of whether or not to continue using this kind of app turns into a trade-off issue. To delve into the determinants, we conduct an online survey and collect 242 qualified responses as our research samples. Structural equation modeling is employed to analyze the samples in this study. The result reveals that our research model explains 31% of the variance. The findings and implications can serve as references for researchers and practitioners.

Gastropericardial fistula and Candida albicans pericarditis: a rare complication of gastric adenocarcinoma treated with radiation and chemotherapy.

Gastropericardial fistula is generally associated with benign gastric diseases and is an uncommon complication of gastric adenocarcinoma. Pericarditis and cardiac tamponade are the ultimate outcome, with extremely high mortality rates. We report a 47-year-old man with gastric adenocarcinoma who had completed radiotherapy and was on scheduled chemotherapy, who presented with fever and chest pain. Gastric adenocarcinoma complicated with gastropericardial fistula and Candida albicans pericarditis were diagnosed and treated successfully with conservative management. Initial chest radiography and computed tomography (CT) revealed no evident pericardial air or fluid. However, follow-up panendoscopy 2 weeks later revealed a malignant ulcer with a fistula opening over the lesser curvature of the high body of the stomach. Subsequent chest radiography and CT revealed pneumopericardium with fluid accumulation. Emergent CT-guided pericardial drainage was performed. The fluid was positive for Candida albicans. Total parenteral nutrition and antifungal therapy were administered. The patient refused surgical intervention and survived with medical management alone. This case demonstrates that first, panendoscopy may be safely performed in patients with gastropericardial fistula without significant risk of cardiac tamponade; second, although early diagnosis of gastropericardial fistula is generally important, delayed recognition may not lead to devastating outcomes even in the absence of surgical intervention.

Cholestatic jaundice as the predominant presentation in a patient with autoimmune hepatitis.

Autoimmune hepatitis is a heterogeneous liver disease of unknown etiology. It is predominant in females and characterized by elevation of transaminase, hypergammaglobulinemia and circulating autoantibodies. Interface hepatitis and plasma cell infiltration are the main findings on liver biopsy. However, deep cholestatic jaundice is rarely seen. We present here an unusual case of type 1 autoimmune hepatitis with hyperbilirubinemia as the initial and predominant presentation. Although rare, autoimmune hepatitis should be considered in patients with cholestasis without history of drug or viral hepatitis.

Nonalcoholic fatty liver disease manifesting esophageal variceal bleeding.

Nonalcoholic fatty liver disease (NAFLD) is a fatty liver disease occurring in patients without alcohol consumption. It includes a broad spectrum of liver disease, from fatty infiltration, inflammation and fibrosis, to cirrhosis, usually having obesity, hyperlipidemia, and diabetes mellitus as its etiology. NAFLD-related cirrhosis has rarely been reported in Taiwan. We herein report a 41-year-old male patient with nonalcoholic fatty liver cirrhosis (NAFLC), with the first clinical manifestation being bleeding esophageal varices (EV). The patient was obese with diabetes mellitus, but without hyperlipidemia or any history of drinking alcohol. The laboratory tests, abdominal sonography, and computed tomography revealed a typical case of liver cirrhosis. The pan-endoscopy disclosed EV with red-color sign. EV ligation was performed successfully to stop the bleeding. When the patient was in a stabilized clinical condition, a liver biopsy showed a typical histologic finding of NAFLD. Most of the cases of NAFLC reported in the literature have silent signs and symptoms. Sudden onset of the EV as the first clinical manifestation, as in this case, is rare. This case reminds us that NAFLD may indeed induce severe liver impairment, such as liver cirrhosis. Liver biochemical tests and abdominal sonography should be considered in patients with overt obesity and diabetes.