Capsule endoscopy and panendoscopy:A journey to the future of gastrointestinal endoscopy

In 2000,the small bowel capsule revolutionized the management of patients with small bowel disorders.Currently,the technological development achieved by the new models of double-headed endoscopic capsules,as miniaturized devices to evaluate the small bowel and colon[pan-intestinal capsule endoscopy(PCE)],makes this non-invasive procedure a disruptive concept for the management of patients with digestive disorders.This technology is expected to identify which patients will require conventional invasive endoscopic procedures(colonoscopy or balloon-assisted enteroscopy),based on the lesions detected by the capsule,i.e.,those with an indication for biopsies or endoscopic treatment.The use of PCE in patients with inflammatory bowel diseases,namely Crohn’s disease,as well as in patients with iron deficiency anaemia and/or overt gastrointestinal(GI)bleeding,after a non-diagnostic upper endoscopy(esophagogastroduodenoscopy),enables an effective,safe and comfortable way to identify patients with relevant lesions,who should undergo subsequent invasive endoscopic procedures.The recent development of magnetically controlled capsule endoscopy to evaluate the upper GI tract,is a further step towards the possibility of an entirely non-invasive assessment of all the segments of the digestive tract,from mouth-to-anus,meeting the expectations of the early developers of capsule endoscopy.

Detachable string magnetically controlled capsule endoscopy for the noninvasive diagnosis of esophageal diseases:A prospective,blind clinical study

BACKGROUND Traditional esophagogastroduodenoscopy(EGD),an invasive examination method,can cause discomfort and pain in patients.In contrast,magnetically controlled capsule endoscopy(MCE),a noninvasive method,is being applied for the detection of stomach and small intestinal diseases,but its application in treating esophageal diseases is not widespread.AIM To evaluate the safety and efficacy of detachable string MCE(ds-MCE)for the diagnosis of esophageal diseases.METHODS Fifty patients who had been diagnosed with esophageal diseases were pros-pectively recruited for this clinical study and underwent ds-MCE and conven-tional EGD.The primary endpoints included the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for patients with esophageal diseases.The secondary endpoints consisted of visualizing the esophageal and dentate lines,as well as the subjects'tolerance of the procedure.RESULTS Using EGD as the gold standard,the sensitivity,specificity,positive predictive value,negative predictive value,and diagnostic accuracy of ds-MCE for esophageal disease detection were 85.71%,86.21%,81.82%,89.29%,and 86%,respectively.ds-MCE was more comfortable and convenient than EGD was,with 80%of patients feeling that ds-MCE examination was very comfortable or comfortable and 50%of patients believing that detachable string v examination was very convenient.CONCLUSION This study revealed that ds-MCE has the same diagnostic effects as traditional EGD for esophageal diseases and is more comfortable and convenient than EGD,providing a novel noninvasive method for treating esophageal diseases.

Convolutional neural network-based segmentation network applied to image recognition of angiodysplasias lesion under capsule endoscopy

BACKGROUND Small intestinal vascular malformations(angiodysplasias)are common causes of small intestinal bleeding.While capsule endoscopy has become the primary diagnostic method for angiodysplasia,manual reading of the entire gastrointestinal tract is time-consuming and requires a heavy workload,which affects the accuracy of diagnosis.AIM To evaluate whether artificial intelligence can assist the diagnosis and increase the detection rate of angiodysplasias in the small intestine,achieve automatic disease detection,and shorten the capsule endoscopy(CE)reading time.METHODS A convolutional neural network semantic segmentation model with a feature fusion method,which automatically recognizes the category of vascular dysplasia under CE and draws the lesion contour,thus improving the efficiency and accuracy of identifying small intestinal vascular malformation lesions,was proposed.Resnet-50 was used as the skeleton network to design the fusion mechanism,fuse the shallow and depth features,and classify the images at the pixel level to achieve the segmentation and recognition of vascular dysplasia.The training set and test set were constructed and compared with PSPNet,Deeplab3+,and UperNet.RESULTS The test set constructed in the study achieved satisfactory results,where pixel accuracy was 99%,mean intersection over union was 0.69,negative predictive value was 98.74%,and positive predictive value was 94.27%.The model parameter was 46.38 M,the float calculation was 467.2 G,and the time length to segment and recognize a picture was 0.6 s.CONCLUSION Constructing a segmentation network based on deep learning to segment and recognize angiodysplasias lesions is an effective and feasible method for diagnosing angiodysplasias lesions.

Understanding deep learning in capsule endoscopy: Can artificial intelligence enhance clinical practice?

Wireless capsule endoscopy(WCE)enables physicians to examine the gastrointestinal tract by transmitting images wirelessly from a disposable capsule to a data recorder.Although WCE is the least invasive endoscopy technique for diagnosing gastrointestinal disorders,interpreting a WCE study requires significant time effort and training.Analysis of images by artificial intelligence,through advances such as machine or deep learning,has been increasingly applied to medical imaging.There has been substantial interest in using deep learning to detect various gastrointestinal disorders based on WCE images.This article discusses basic knowledge of deep learning,applications of deep learning in WCE,and the implementation of deep learning model in a clinical setting.We anticipate continued research investigating the use of deep learning in interpreting WCE studies to generate predictive algorithms and aid in the diagnosis of gastrointestinal disorders.

Role of capsule endoscopy in inflammatory bowel disease:Anything new?

Capsule endoscopy(CE)is a recently developed diagnostic method for diseases of the small bowel that is non-invasive,safe,and highly tolerable.Its role in patients with inflammatory bowel disease has been widely validated in suspected and established Crohn’s disease(CD)due to its ability to assess superficial lesions not detected by cross-sectional imaging and proximal lesions of the small bowel not evaluable by ileocolonoscopy.Because CE is a highly sensitive but less specific technique,differential diagnoses that can simulate CD must be considered,and its interpretation should be supported by other clinical and laboratory indicators.The use of validated scoring systems to characterize and estimate lesion severity(Lewis score,Capsule Endoscopy Crohn’s Disease Activity Index),as well as the standardization of the language used to define the lesions(Delphi Consensus),have reduced the interobserver variability in CE reading observed in clinical practice,allowing for the optimization of diagnoses and clinical management strategies.The appearance of the panenteric CE,the incorporation of artificial intelligence,magnetically-guided capsules,and tissue biopsies are elements that contribute to CE being a promising,unique diagnostic tool in digestive tract diseases.

Fields of applications,diagnostic yields and findings of OMOM capsule endoscopy in 2400 Chinese patients

AIM:To retrospectively analyze the fields of application,diagnostic yields and findings of OMOM capsule endoscopy in Chinese patients.METHODS:A database including 2400 Chinese patients who received OMOM capsule endoscopy in 27 endoscopy centers in China was retrieved from the Jianshan Science and Technology Ltd.OMOM capsule endoscopy database.The patient's age,gender,fields of application,the potentially relevant findings,pyloric transit time(PTT),small bowel transit time(SBTT),and complete small-bowel examination rate(CSER) were recorded and analyzed.RESULTS:Two thousand four hundred patients aged 9-91 years(mean,49 years),of whom 1510 were males(62.9%),underwent 2400 OMOM capsule endoscopy procedures.One thousand two hundred and thirty two(51.3%) were referred with obscure gastrointestinal bleeding(OGIB),642(26.8%) with abdominal pain,and 223(9.3%) with chronic diarrhea.The overall diagnostic yield was 47.7%(1144/2400).The diagnostic yield of OMOM capsule endoscopy in OGIB subgroup was much higher than in the non-OGIB subgroup(62.4% vs 32.1%,P<0.001).The most common findings of the small bowel in Chinese patients with OGIB were arteriovenous malformation(28.1%) and tumors(18.9%).There was no significant difference in the diagnostic yield between the male and female patients with OGIB.However,the diagnostic yield in patients aged more than 60 was higher than in patients aged less than 60(69.8% vs 58.9%,P<0.001).The median PTT was 41 min(range:1-544 min) and the mean SBTT was 247.2 ± 88.9 min.The overall CSER was 86.8%.CONCLUSION:The OMOM capsule endoscopy is a valuable tool for small bowel evaluation with good overall diagnostic yield and CSER.

Factors associated with incomplete small bowel capsule endoscopy studies

AIM:To identify patient risk factors associated with incomplete small bowel capsule endoscopy(CE) studies.METHODS:Data from all CE procedures performed at St.Paul's Hospital in Vancouver,British Columbia,Canada,between December 2001 and June 2008 were collected and analyzed on a retrospective basis.Data collection for complete and incomplete CE study groups included patient demographics as well as a number of potential risk factors for incomplete CE including indication for the procedure,hospitalization,diabetes mellitus with or without end organ damage,limitations in mobility,renal insufficiency,past history of bowel obstruction,abdominal surgery,abdominal radiation therapy and opiate use.Risk factors were analyzed using a univariable and multivariable logistic regression model.RESULTS:From a total of 535 CE procedures performed,158 were incomplete(29.5%).The univariable analysis showed that CE procedures performed for overt gastrointestinal bleeding(P = 0.002),and for patients with a prior history of abdominal surgery(P = 0.023) or bowel obstruction(P = 0.023) were significantly associated with incomplete CE studies.Patients on opiate medications(P = 0.094) as well as hospitalized patients(P = 0.054) were not statistically significant,but did show a trend towards incomplete CE.The multivariable analysis showed that independent risk factors for an incomplete CE procedure include prior history of bowel obstruction [odds ratios(OR) 2.77,P = 0.02,95% confidence intervals(CI):1.17-6.56] and procedures performed for gastrointestinal bleeding(Occult OR 2.04,P = 0.037,95% CI:1.04-4.02 and Overt OR 2.69,P = 0.002,95% CI:1.44-5.05).Patients with a prior history of abdominal surgery(OR 1.46,P = 0.068,95% CI:0.97-2.19),those taking opiate medications(OR 1.54,P = 0.15,95% CI:0.86-2.76) and hospitalized patients(OR 1.82,P = 0.124,95% CI:0.85-3.93) showed a trend towards statistical significance.CONCLUSION:We have identified a number of risk factors for incomplete CE procedures that can be used to risk-stratify patients and guide interventions to improve completion rates.

Wireless capsule endoscopy and proximal small bowel lesions in Crohn’s disease

AIM: To investigate the prevalence of proximal small bowel (SB) lesions detected by wireless capsule endoscopy (WCE) in Crohn's disease (CD). METHODS: WCE was performed in 64 patients: 32 with CD of the distal ileum, and 32 controls with iron-deficiency anemia (IDA) or diarrhea. WCE was performed using the Given SB-WCE, followed by small intestine contrast ultrasonography (SICUS). Findings compatible with CD by using WCE included erosions, aphthoid or deep ulcers, and strictures/stenosis. RESULTS: WCE detected proximal SB lesions in 16/32 (50%) patients (14 aphthoid ulcers, 2 deep ulcers, one stricture), which appeared not to be related to clinical parameters [epigastric pain, age, smoking, non-steroidalanti-inflammatory drugs (NSAIDs), IDA]. Among patients with proximal SB lesions, 6 (37%) were smokers, 3 (19%) NSAID users, 3 (19%) had epigastric pain and 4 (25%) had IDA. SICUS detected proximal SB lesions in 3/32 patients (19%) also showing lesions with WCE. No correlations were observed between proximal SB lesions assessed by WCE or by SICUS (χ2 = 1.5, P = 0.2). CONCLUSION: The use of WCE allows the detection of previously unknown upper SB lesions in a high proportion of patients with a previous diagnosis of CD involving the distal ileum.

Meta-analysis of capsule endoscopy in patients diagnosed or suspected with esophageal varices

The PillCam ESO(Given Imaging,Israel) or esophageal capsule endoscopy(ECE) is a novel technique used in the diagnostic evaluation of esophagus.Many studies have been performed to compare the accuracy of ECE against the current gold standard esophagogastro-duodenoscopy and a meta-analysis recently published by Lu et al suggests that ECE may have an acceptable sensitivity and specificity in detecting esophageal varices.We would like to discuss the importance and implication of publication bias in this meta-analysis.

A novel cleansing score system for capsule endoscopy

AIM:To suggest a new cleansing score system for small bowel preparation and to evaluate its clinical efficacy.METHODS:Twenty capsule endoscopy cases were reviewed and small bowel preparation was assessed with the new scoring system.For the assessment,two visual parameters were used:proportion of visualized mucosa and degree of obscuration.Representative frames from small bowel images were serially selected and scored at 5-min intervals.Intraclass correlation coefficient(ICC)was obtained to assess the reliability of the new scoring system.For efficacy evaluation and validation,scores of our new scoring system were compared with another previously reported cleansing grading system.RESULTS:Concordance with the previous system,inter-observer agreement,and intra-patient agreement were excellent with ICC values of 0.82,0.80,and 0.76,respectively.The intra-observer agreements at four-week intervals were also excellent.The cutoff value of adequate image quality was found to be 2.25.CONCLUSION:Our new scoring system is simple,efficient,and can be considered to be applicable in clinical practice and research.

Role of wireless capsule endoscopy in inflammatory bowel disease

Capsule endoscopy(CE) offers state-of-the-art imaging of the small bowel.In Crohn's disease its clinical role is still uncertain.This report analyses the usefulness of CE in patients with suspected Cronh's disease,in patients with established Crohn's disease(when assessing severity,occult gastrointestinal bleeding and/or as a guide to therapy),in patients with inflammatory bowel disease unclassified(IBDU),and in individuals with ulcerative colitis.The first item in this group is the most important although there is no strong evidence to establish the position of CE in the diagnostic workup.In patients with established Crohn's disease,recently developed activity scores are promising tools for an accurate assessment of severity.As a guide to therapy,CE should be focused on patients with unexplained symptoms when other investigations are inconclusive.In postoperative Crohn's Disease,international consensus recommended considering CE only ifileocolonoscopy is contraindicated or unsuccessful.In the case of IBDU,studies have shown a significant proportion of patients reclassified with Crohn's disease.In this setting,CE could have a role determining small bowel involvement.The role of CE in ulcerative colitis is limited.Some authors advocate CE before colectomy for refractory cases in order to exclude Crohn's disease.In summary,CE offers a new horizon in inflammatory bowel disease,and a better knowledge of mucosal abnormalities that could offer a paradigm shift:changing from symptombased disease activity estimation to direct mucosal healing monitoring.Nevertheless,randomized controlled studies are still needed to provide stronger evidence in this setting.

Enhanced segmentation of gastrointestinal polyps from capsule endoscopy images with artifacts using ensemble learning

BACKGROUND Endoscopy artifacts are widespread in real capsule endoscopy(CE)images but not in high-quality standard datasets.AIM To improve the segmentation performance of polyps from CE images with artifacts based on ensemble learning.METHODS We collected 277 polyp images with CE artifacts from 5760 h of videos from 480 patients at Guangzhou First People’s Hospital from January 2016 to December 2019.Two public high-quality standard external datasets were retrieved and used for the comparison experiments.For each dataset,we randomly segmented the data into training,validation,and testing sets for model training,selection,and testing.We compared the performance of the base models and the ensemble model in segmenting polyps from images with artifacts.RESULTS The performance of the semantic segmentation model was affected by artifacts in the sample images,which also affected the results of polyp detection by CE using a single model.The evaluation based on real datasets with artifacts and standard datasets showed that the ensemble model of all state-of-the-art models performed better than the best corresponding base learner on the real dataset with artifacts.Compared with the corresponding optimal base learners,the intersection over union(IoU)and dice of the ensemble learning model increased to different degrees,ranging from 0.08%to 7.01%and 0.61%to 4.93%,respectively.Moreover,in the standard datasets without artifacts,most of the ensemble models were slightly better than the base learner,as demonstrated by the IoU and dice increases ranging from-0.28%to 1.20%and-0.61%to 0.76%,respectively.CONCLUSION Ensemble learning can improve the segmentation accuracy of polyps from CE images with artifacts.Our results demonstrated an improvement in the detection rate of polyps with interference from artifacts.

Essential role of small bowel capsule endoscopy in reclassification of colonic inflammatory bowel disease type unclassified

AIM To evaluate the role of small bowel capsule endoscopy(SBCE) on the reclassification of colonic inflammatory bowel disease type unclassified(IBDU).METHODS We performed a multicenter, retrospective study including patients with IBDU undergoing SBCE, between 2002 and 2014. SBCE studies were reviewed and the inflammatory activity was evaluated by determining the Lewis score(LS). Inflammatory activity was considered significant and consistent with Crohn's disease(CD) when the LS ≥ 135. The definitive diagnosis during follow-up(minimum 12 mo following SBCE) was based on the combination of clinical, analytical, imaging, endoscopic and histological elements.RESULTS Thirty-six patients were included, 21 females(58%) with mean age at diagnosis of 33 ± 13(15-64) years. The mean follow-up time after the SBCE was 52 ± 41(12-156) mo. The SBCE revealed findings consistent with significant inflammatory activity in the small bowel(LS ≥ 135) in 9 patients(25%); in all of them the diagnosis of CD was confirmed during follow-up. In 27 patients(75%), the SBCE revealed no significant inflammatory activity(LS < 135); among these patients, the diagnosis of Ulcerative Colitis(UC) was established in 16 cases(59.3%), CD in 1 case(3.7%) and 10 patients(37%) maintained a diagnosis of IBDU during follow-up. A LS ≥ 135 at SBCE had a sensitivity = 90%, specificity = 100%, positive predictive value = 100% and negative predictive value = 94% for the diagnosis of CD.CONCLUSION SBCE proved to be fundamental in the reclassification of patients with IBDU. Absence of significant inflammatory activity in the small intestine allowed exclusion of CD in 94% of cases.

First prospective European study for the feasibility and safety of magnetically controlled capsule endoscopy in gastric mucosal abnormalities

BACKGROUND While capsule endoscopy(CE)is the gold standard diagnostic method of detecting small bowel(SB)diseases and disorders,a novel magnetically controlled capsule endoscopy(MCCE)system provides non-invasive evaluation of the gastric mucosal surface,which can be performed without sedation or discomfort.During standard SBCE,passive movement of the CE may cause areas of the complex anatomy of the gastric mucosa to remain unexplored,whereas the precision of MCCE capsule movements inside the stomach promises better visualization of the entire mucosa.AIM To evaluate the Ankon MCCE system’s feasibility,safety,and diagnostic yield in patients with gastric or SB disorders.METHODS Of outpatients who were referred for SBCE,284(male/female:149/135)were prospectively enrolled and evaluated by MCCE.The stomach was examined in the supine,left,and right lateral decubitus positions without sedation.Next,all patients underwent a complete SBCE study protocol.The gastric mucosa was explored with the Ankon MCCE system with active magnetic control of the capsule endoscope in the stomach,applying three standardized pre-programmed computerized algorithms in combination with manual control of the magnetic movements.RESULTS The urea breath test revealed Helicobacter pylori positivity in 32.7%of patients.The mean gastric and SB transit times with MCCE were 0 h 47 min 40 s and 3 h 46 min 22 s,respectively.The average total time of upper gastrointestinal MCCE examination was 5 h 48 min 35 s.Active magnetic movement of the Ankon capsule through the pylorus was successful in 41.9%of patients.Overall diagnostic yield for detecting abnormalities in the stomach and SB was 81.9%(68.6%minor;13.3%major pathologies);25.8%of abnormalities were in the SB;74.2%were in the stomach.The diagnostic yield for stomach/SB was 55.9%/12.7%for minor and 4.9%/8.4%for major pathologies.CONCLUSION MCCE is a feasible,safe diagnostic method for evaluating gastric mucosal lesions and is a promising non-invasive screening tool to decrease morbidity and mortality in upper gastrointestinal diseases.

Detection of small bowel tumor in wireless capsule endoscopy images using an adaptive neuro-fuzzy inference system

Automatic diagnosis tool helps physicians to evaluate capsule endoscopic examinations faster and more accurate.The purpose of this study was to evaluate the validity and reliability of an automatic post-processing method for identifying and classifying wireless capsule endoscopic images, and investigate statistical measures to differentiate normal and abnormal images. The proposed technique consists of two main stages, namely, feature extraction and classification. Primarily, 32 features incorporating four statistical measures(contrast, correlation, homogeneity and energy) calculated from co-occurrence metrics were computed. Then, mutual information was used to select features with maximal dependence on the target class and with minimal redundancy between features. Finally, a trained classifier, adaptive neuro-fuzzy interface system was implemented to classify endoscopic images into tumor, healthy and unhealthy classes. Classification accuracy of 94.2% was obtained using the proposed pipeline. Such techniques are valuable for accurate detection characterization and interpretation of endoscopic images.

Impact of the timing of capsule endoscopy in overt obscure gastrointestinal bleeding on yield and rebleeding rate-is sooner than 14 d advisable?

AIM To evaluate the impact of the timing of capsule endoscopy(CE) in overt-obscure gastrointestinal bleeding(OGIB). METHODS Retrospective, single-center study, including patients submitted to CE in the setting of overt-OGIB between January 2005 and August 2017. Patients were divided into 3 groups according to the timing of CE(≤ 48 h; 48 h-14 d; ≥ 14 d). The diagnostic and therapeutic yield(DY and TY), the rebleeding rate and the time to rebleed were calculated and compared between groups. The outcomes of patients in whom CE was performed before(≤ 48 h) and after 48 h(> 48 h), and before(< 14 d) and after 14 d(≥ 14 d), were alsocompared.RESULTS One hundred and fifteen patients underwent CE for overt-OGIB. The DY was 80%, TY-46.1% and rebleeding rate-32.2%. At 1 year 17.8% of the patients had rebled. 33.9% of the patients performed CE in the first 48 h, 30.4% between 48 h-14 d and 35.7% after 14 d. The DY was similar between the 3 groups(P = 0.37). In the ≤ 48 h group, the TY was the highest(66.7% vs 40% vs 31.7%, P = 0.005) and the rebleeding rate was the lowest(15.4% vs 34.3% vs 46.3% P = 0.007). The time to rebleed was longer in the ≤ 48 h group when compared to the > 48 h groups(P = 0.03).CONCLUSION Performing CE within 48 h from overt-OGIB is associated to a higher TY and a lower rebleeding rate and longer time to rebleed.

Follow-up outcomes in patients with negative initial colon capsule endoscopy findings

BACKGROUND Colon capsule endoscopy(CCE),which became clinically applicable in 2006,is a simple and noninvasive procedure to evaluate colonic diseases;the accuracy of second-generation CCE,introduced in 2009,has dramatically improved.Currently,CCE is used as an alternative method for colorectal cancer screening,as well as for evaluating the mucosal lesions of inflammatory bowel disease,in cases where performing colonoscopy(CS)is difficult.However,the outcomes of CCE are uncertain.AIM To investigate the outcomes of Japanese patients with negative findings(no polyps or colorectal cancer)on initial CCE.METHODS This retrospective,single-center study was conducted at the Endoscopic Center at Aishinkai Nakae Hospital.This study included patients who underwent continuous CCE between November 2013 and August 2019,that exhibited no evidence of polyps or colorectal cancer at the initial CCE,and could be followed up using either the fecal immunochemical test(FIT),CS,or CCE.The observational period,follow-up method,presence or absence of polyps and colorectal cancer,pathological diagnosis,and number of colorectal cancer deaths were evaluated.RESULTS Thirty-one patients(mean age,60.4±15.6 years;range,28–84 years;14 men and 17 women)were enrolled in this study.The reasons for performing the first CCE were screening in 12,a positive FIT in six,lower abdominal pain in nine,diarrhea in two,and anemia in two patients.The mean total water volume at the time of examination was 3460±602 mL(2250–4800 mL),and a total CS was performed in 28 patients(90%).The degree of cleanliness was excellent in 15 patients and good in 16,and no poor cases were observed.No adverse events,such as retention or capsule aspiration,were observed in any of the patients.The mean follow-up period was 3.1±1.5 years(range,0.3–5.5 years).Follow-up included FIT in nine,CS in 20,and CCE in four patients(including duplicate patients).The FIT was positive in two patients,while CS revealed five polyp lesions(three in the ascending colon,one in the transverse colon,and one in the descending colon),with sizes ranging between 2 mm and 8 mm.Histopathological findings revealed a hyperplastic polyp in one patient,and adenoma with low grade dysplasia in four patients;colorectal cancers were not recognized.In the follow-up example by CCE,polyps and colorectal cancer could not be recognized.During the follow-up period,there were no deaths due to colorectal cancer in any of the patients.CONCLUSION We determined the outcomes in patients with negative initial CCE findings.

Improving CAD Hemorrhage Detection in Capsule Endoscopy

This study explores an automated framework to assist the recognition of hemorrhage traces and bleeding lesions in video streams of small bowel capsule endoscopy (SBCE). The proposed methodology aims to achieve fast image control (<10 minutes), save valuable time of the physicians, and enable high performance diagnosis. A specialized elimination algorithm excludes all identical consecutive frames by utilizing the difference of gray levels in pixel luminance. An image filtering algorithm is proposed based on an experimentally calculated bleeding index and blood-color chart, which inspects all remaining frames of the footage and identifies pixels that reflect active or potential hemorrhage in color. The bleeding index and blood-color chart are estimated of the chromatic thresholds in RGB and HSV color spaces, and have been extracted after experimenting with more than 3200 training images, derived from 99 videos of a pool of 138 patients. The dataset has been provided by a team of expert gastroenterologist surgeons, who have also evaluated the results. The proposed algorithms are tested on a set of more than 1000 selected frame samples from the entire 39 testing videos, to a prevalence of 50% pathologic frames (balanced dataset). The frame elimination of identical and consecutive frames achieved a reduction of 36% of total frames. The best statistical performance for diagnosis of positive pathological frames from a video stream is achieved by utilizing masks in the HSV color model, with sensitivity up to 99%, precision 94.41% to a prevalence of 50%, accuracy up to 96.1%, FNR 1%, FPR 6.8%. The estimated blood-color chart will be clinically validated and used in feature extraction schemes supporting machine learning ML algorithms to improve the localization potential.

The Use of Castor Oil for Bowel Preparation for Colon Capsule Endoscopy

Colon capsule endoscopy was approved for reimbursement under the national health insurance system of Japan in 2014. At our hospital, specialized mainly in renal, hepatic, and diabetic diseases, we have been performing colon capsule endoscopy since December 2014. Dialysis patients are potentially susceptible to bleeding because of the fragile intestine, impaired platelet function, or oral administration of nonsteroidalanti inflammatory drugs (NSAIDs) or anticoagulants. For this reason, detailed examination by capsule endoscopy appears to be useful. However, the capsule excretion rate after recommended bowel preparation reportedly ranges from 70% to 90%, and administration of boosters is also necessary. For dialysis patients, liquid loading is a problem. In this study, we evaluated the efficacy of bowel preparation with castor oil for improving the capsule excretion rate. In all 20 patients (including four dialysis patients), both capsule transit time and duration of capsule endoscopy were shortened. The results are presented and briefly discussed in this report.

Inverted Meckel’s diverticulum diagnosed using capsule endoscopy: A case report

BACKGROUND Meckel’s diverticulum is a common asymptomatic congenital gastrointestinal anomaly.However,its presentation as an inverted Meckel's diverticulum is a rare complication,of which few cases have been reported in the literature.CASE SUMMARY Here,we report the case of a 33-year-old man with iron deficiency anemia without manifestation of gastrointestinal bleeding.An upper gastrointestinal endoscopy and total colonoscopy were performed,but no abnormalities were found within the observed area.Finally,a capsule endoscopy was performed and offered us a clue to subsequently confirm the diagnosis of inverted Meckel's diverticulum via computed tomography scan.Laparoscopic intestinal resection surgery was performed.The final pathology report described a Meckel’s diverticulum.CONCLUSION Since inverted Meckel's diverticulum is an uncommon disease and its clinical presentation is not specific,it may go undetected by capsule endoscopy.Successful diagnosis and treatment of this disease requires a high index of clinical suspicion.