AIM: To investigate visceral fat accumulation in association with the risk of small bowel angioectasia.METHODS: We retrospectively investigated 198 consecutive patients who underwent both capsule endoscopy and CT for ...AIM: To investigate visceral fat accumulation in association with the risk of small bowel angioectasia.METHODS: We retrospectively investigated 198 consecutive patients who underwent both capsule endoscopy and CT for investigation of obscure gastrointestinal bleeding(OGIB) from January 2009 to September 2013. The visceral fat area(VFA) and subcutaneous fat area were measured by CT, and information on comorbidities, body mass index, and medications was obtained from their medical records.Logistic regression analysis was used to evaluate associations.RESULTS: Capsule endoscopy revealed small bowel angioectasia in 18/198(9.1%) patients with OGIB.Compared to patients without small bowel angioectasia,those with small bowel angioectasia had a significantly higher VFA(96 ± 76.0 cm2 vs 63.4 ±51.5 cm2, P = 0.016) and a higher prevalence of liver cirrhosis(61% vs 22%, P < 0.001). The proportion of patients with chronic renal failure was higher in patients with small bowel angioectasia(22% vs 9%,P = 0.11). There were no significant differences in subcutaneous fat area or waist circumference. The prevalence of small bowel angioectasia progressively increased according to the VFA. Multivariate analysis showed that the VFA [odd ratio(OR) for each 10-cm2 increment = 1.1; [95% confidence interval(CI):1.02-1.19; P = 0.021] and liver cirrhosis(OR = 6.1,95%CI: 2.2-18.5; P < 0.001) were significant risk factors for small bowel angioectasia.CONCLUSION: VFA is positively associated with theprevalence of small bowel angioectasia, for which VFA and liver cirrhosis are independent risk factors in patients with OGIB.展开更多
The proposed deep learning algorithm will be integrated as a binary classifier under the umbrella of a multi-class classification tool to facilitate the automated detection of non-healthy deformities, anatomical landm...The proposed deep learning algorithm will be integrated as a binary classifier under the umbrella of a multi-class classification tool to facilitate the automated detection of non-healthy deformities, anatomical landmarks, pathological findings, other anomalies and normal cases, by examining medical endoscopic images of GI tract. Each binary classifier is trained to detect one specific non-healthy condition. The algorithm analyzed in the present work expands the ability of detection of this tool by classifying GI tract image snapshots into two classes, depicting haemorrhage and non-haemorrhage state. The proposed algorithm is the result of the collaboration between interdisciplinary specialists on AI and Data Analysis, Computer Vision, Gastroenterologists of four University Gastroenterology Departments of Greek Medical Schools. The data used are 195 videos (177 from non-healthy cases and 18 from healthy cases) videos captured from the PillCam<sup>(R)</sup> Medronics device, originated from 195 patients, all diagnosed with different forms of angioectasia, haemorrhages and other diseases from different sites of the gastrointestinal (GI), mainly including difficult cases of diagnosis. Our AI algorithm is based on convolutional neural network (CNN) trained on annotated images at image level, using a semantic tag indicating whether the image contains angioectasia and haemorrhage traces or not. At least 22 CNN architectures were created and evaluated some of which pre-trained applying transfer learning on ImageNet data. All the CNN variations were introduced, trained to a prevalence dataset of 50%, and evaluated of unseen data. On test data, the best results were obtained from our CNN architectures which do not utilize backbone of transfer learning. Across a balanced dataset from no-healthy images and healthy images from 39 videos from different patients, identified correct diagnosis with sensitivity 90%, specificity 92%, precision 91.8%, FPR 8%, FNR 10%. Besides, we compared the performance of our best CNN algorithm versus our same goal algorithm based on HSV colorimetric lesions features extracted of pixel-level annotations, both algorithms trained and tested on the same data. It is evaluated that the CNN trained on image level annotated images, is 9% less sensitive, achieves 2.6% less precision, 1.2% less FPR, and 7% less FNR, than that based on HSV filters, extracted from on pixel-level annotated training data.展开更多
AIM:To define which segments of the gastrointestinal tract are most likely to yield angioectasias for ablative therapy. METHODS:A retrospective chart review was performed for patients treated in the Louisiana State Un...AIM:To define which segments of the gastrointestinal tract are most likely to yield angioectasias for ablative therapy. METHODS:A retrospective chart review was performed for patients treated in the Louisiana State University Health Sciences Center Gastroenterology clinics between the dates of July 1, 2007 and October 1, 2010. The selection of cases for review was initiated by use of our electronic medical record to identify all patients with a diagnosis of angioectasia, angiodysplasia, or arteriovenous malformation. Of these cases, chart reviews identified patients who had a complete evaluation of their gastrointestinal tract as defined by at least one upper endoscopy, colonoscopy and small bowel capsule endoscopy within the past three years. Patients without evidence of overt gastrointestinal bleeding or iron deficiency anemia associated with intestinal angioectasias were classified as asymptomatic and excluded from this analysis. Thirty-five patients with confirmed, bleeding intestinal angioectasias who had undergone complete endoscopic evaluation of the gastrointestinal tract were included in the final analysis. RESULTS:A total of 127 cases were reviewed. Sixtysix were excluded during subsequent screening due to lack of complete small bowel evaluation and/or lack of documentation of overt bleeding or iron deficiency anemia. The 61 remaining cases were carefully examined with independent review of endoscopic images as well as complete capsule endoscopy videos. This anal- ysis excluded 26 additional cases due to insufficient records/images for review, incomplete capsule examination, poor capsule visualization or lack of confirmation of typical angioectasias by the principal investigator on independent review. Thirty-five cases met criteria for final analysis. All study patients were age 50 years or older and 13 patients (37.1%) had chronic kidney disease stage 3 or higher. Twenty of 35 patients were taking aspirin (81 mg or 325 mg), clopidogrel, and/or warfarin, with 8/20 on combination therapy. The number and location of angioectasis was documented for each case. Lesions were then classified into the following segments of the gastrointestinal tract:esophagus, stomach, duodenum, jejunum, ileum, right colon and left colon. The location of lesions within the small bowel observed by capsule endoscopy was generally defined by percentage of total small bowel transit time with times of 0%-9%, 10%-39%, and 40%-100% corresponding to the duodenum, jejunum and ileum, respectively. Independent review of complete capsule studies allowed for deviation from this guideline if capsule passage was delayed in one or more segments. In addition, the location and number of angioectasias observed in the small bowel was further modified or confirmed by subsequent device-assisted enteroscopy (DAE) performed in the 83% of cases. In our study population, angioectasias were most commonly found in the jejunum (80%) followed by the duodenum (51%), stomach (22.8%), and right colon (11.4%). Only two patients were found to have angioectasias in the ileum (5.7%). Twenty-one patients (60%) had angioectasias in more than one location.CONCLUSION:Patients being considered for endoscopic ablation of symptomatic angioectasias should undergo push enteroscopy or anterograde DAE and reinspection of the right colon.展开更多
Gastrointestinal angiodysplasias (GIADs), also called angioectasias, are the most frequent vascular lesions. Its precise prevalence is unknown since most of them are asymptomatic. However, the incidence may be increas...Gastrointestinal angiodysplasias (GIADs), also called angioectasias, are the most frequent vascular lesions. Its precise prevalence is unknown since most of them are asymptomatic. However, the incidence may be increasing since GIADs affect individuals aged more than 60 years and population life expectancy is globally increasing worldwide. They are responsible of about 5% to 10% of all gastrointestinal bleeding (GIB) cases. Most GIADs are placed in small bowel, where are the cause of 50 to 60% of obscure GIB diagnosed with video capsule endoscopy. They may be the cause of fatal severe bleeding episodes;nevertheless, recurrent overt or occult bleeding episodes requiring repeated expensive treatments and disturbing patient’s quality-of-life are more frequently observed. Diagnosis and treatment of GIADs (particularly those placed in small bowel) are a great challenge due to insidious disease behavior, inaccessibility to affected sites and limitations of available diagnostic procedures. Hemorrhagic causality out of the actively bleeding lesions detected by diagnostic procedures may be difficult to establish. No treatment guidelines are currently available, so there is a high variability in the management of these patients. In this review, the epidemiology and pathophysiology of GIADs and the status in the diagnosis and treatment, with special emphasis on small bowel angiodysplasias based on multiple publications, are critically discussed. In addition, a classification of GIADs based on their endoscopic characteristics is proposed. Finally, some aspects that need to be clarified in future research studies are highlighted.展开更多
Small bowel vascular lesions, including angioectasia (AE), Dieulafoy’s lesion (DL) and arteriovenous malformation (AVM), are the most common causes of obscure gastrointestinal bleeding. Since AE are considered to be ...Small bowel vascular lesions, including angioectasia (AE), Dieulafoy’s lesion (DL) and arteriovenous malformation (AVM), are the most common causes of obscure gastrointestinal bleeding. Since AE are considered to be venous lesions, they usually manifest as a chronic, well-compensated condition. Subsequent to video capsule endoscopy, deep enteroscopy can be applied to control active bleeding or to improve anemia necessitating blood transfusion. Despite the initial treatment efficacy of argon plasma coagulation (APC), many patients experience re-bleeding, probably because of recurrent or missed AEs. Pharmacological treatments can be considered for patients who have not responded well to other types of treatment or in whom endoscopy is contraindicated. Meanwhile, a conservative approach with iron supplementation remains an option for patients with mild anemia. DL and AVM are considered to be arterial lesions;therefore, these lesions frequently cause acute life-threatening hemorrhage. Mechanical hemostasis using endoclips is recommended to treat DLs, considering the high re-bleeding rate after primary APC cauterization. Meanwhile, most small bowel AVMs are large and susceptible to re-bleeding therefore, they usually require surgical resection. To achieve optimal diagnostic and therapeutic approaches for each type of small bowel lesion, the differences in their epidemiology, pathology and clinical presentation must be understood.展开更多
Continuous-flow left ventricular assist devices(CF-LVADs)have significantly improved outcomes for patients with end-stage heart failure when used as a bridge to cardiac transplantation or,more recently,as destination ...Continuous-flow left ventricular assist devices(CF-LVADs)have significantly improved outcomes for patients with end-stage heart failure when used as a bridge to cardiac transplantation or,more recently,as destination therapy.However,its implantations carries a risk of complications including infection,device malfunction,arrhythmias,right ventricular failure,thromboembolic disease,postoperative and nonsurgical bleeding.A significant number of left ventricular assist devices(LVAD)recipients may experience recurrent gastrointestinal hemorrhage,mainly due to combination of antiplatelet and vitamin K antagonist therapy,activation of fibrinolytic pathway,acquired von Willebrand factor deficiency,and tendency to develop small intestinal angiodysplasias due to increased rotary speed of the pump.Gastrointestinal bleeding in LVAD patients remains a source of increased morbidity including the need for blood transfusions,extended hospital stays,multiple readmissions,and overall mortality.Management of gastrointestinal bleeding in LVAD patients involves multidisciplinary approach in stabilizing the patients,addressing risk factors and performing structured endoluminal evaluation with focus on upper gastrointestinal tract including jejunum to find and eradicate culprit lesion.Medical and procedural intervention is largely successful and universal bleeding cessation occurs in transplanted patients.展开更多
Splenic rupture is a rare complication of diagnostic and therapeutic gastrointestinal endoscopy procedures.Herein,we report for the first time a case of splenic rupture following therapeutic retrograde double-balloon ...Splenic rupture is a rare complication of diagnostic and therapeutic gastrointestinal endoscopy procedures.Herein,we report for the first time a case of splenic rupture following therapeutic retrograde double-balloon enteroscopy,which occurred in an 85-year-old man who was treated for recurrent mid-intestinal bleeding that resulted from ileal angioectasia.This patient promptly underwent an operation and eventually recovered.展开更多
AIM: To determine the test characteristics of community based video capsule endoscopy (VCE) in patients undergoing sequential VCE and double balloon enteroscopy (DBE). METHODS: Eighty-nine patients (34 females, 55 mal...AIM: To determine the test characteristics of community based video capsule endoscopy (VCE) in patients undergoing sequential VCE and double balloon enteroscopy (DBE). METHODS: Eighty-nine patients (34 females, 55 males, mean age 66) who underwent both VCE and DBE from 2008-2010 were retrospectively reviewed. Lesions detected at VCE were categorized. Capsule directed DBE followed and included 44 antegrade, 11 retrograde and 34 combined antegrade and retrograde procedures. Lesions detected were compared utilizing the McNemar's test. RESULTS: Angioectasia detection with VCE was 25% and with DBE 35% (P < 0.03) with a calculated sensitivity and specificity of 58% and 93% respectively. Polyps were detected by VCE in 22% and in DBE 20%, (P = 0.6), with a sensitivity and specificity for VCE of 61% and 87%. Small bowel diverticula were only seen in 1% of VCE but in 12% of DBE patients (P < 0.002) with a calculated sensitivity and specificity of VCE of 9% and 100%. CONCLUSION: VCE would be moderately sensitiveand specific overall with considerable variation by lesion. Furthermore, VCE cannot be relied upon to diagnose small bowel diverticula.展开更多
To date,limited research has been carried out in developing methods and materials that offer three-dimensional(3-D) representation of the digestive tract.In the field of capsule endoscopy(CE),hardware approaches have ...To date,limited research has been carried out in developing methods and materials that offer three-dimensional(3-D) representation of the digestive tract.In the field of capsule endoscopy(CE),hardware approaches have been developed that provide real time both 3-D information and texture using an infrared projector and a complementary metal oxide semiconductor camera.The major drawbacks of this system are its size,power consumption and packaging issues.A software approach to approximate a 3-D representation of digestive tract surface utilising current CE technology has been proposed.The algorithm utilizes the Shape from Shading technique and seem to provide promising results for polypoid structures and angioectasias.Further clinical evaluation is currently under way.展开更多
文摘AIM: To investigate visceral fat accumulation in association with the risk of small bowel angioectasia.METHODS: We retrospectively investigated 198 consecutive patients who underwent both capsule endoscopy and CT for investigation of obscure gastrointestinal bleeding(OGIB) from January 2009 to September 2013. The visceral fat area(VFA) and subcutaneous fat area were measured by CT, and information on comorbidities, body mass index, and medications was obtained from their medical records.Logistic regression analysis was used to evaluate associations.RESULTS: Capsule endoscopy revealed small bowel angioectasia in 18/198(9.1%) patients with OGIB.Compared to patients without small bowel angioectasia,those with small bowel angioectasia had a significantly higher VFA(96 ± 76.0 cm2 vs 63.4 ±51.5 cm2, P = 0.016) and a higher prevalence of liver cirrhosis(61% vs 22%, P < 0.001). The proportion of patients with chronic renal failure was higher in patients with small bowel angioectasia(22% vs 9%,P = 0.11). There were no significant differences in subcutaneous fat area or waist circumference. The prevalence of small bowel angioectasia progressively increased according to the VFA. Multivariate analysis showed that the VFA [odd ratio(OR) for each 10-cm2 increment = 1.1; [95% confidence interval(CI):1.02-1.19; P = 0.021] and liver cirrhosis(OR = 6.1,95%CI: 2.2-18.5; P < 0.001) were significant risk factors for small bowel angioectasia.CONCLUSION: VFA is positively associated with theprevalence of small bowel angioectasia, for which VFA and liver cirrhosis are independent risk factors in patients with OGIB.
文摘The proposed deep learning algorithm will be integrated as a binary classifier under the umbrella of a multi-class classification tool to facilitate the automated detection of non-healthy deformities, anatomical landmarks, pathological findings, other anomalies and normal cases, by examining medical endoscopic images of GI tract. Each binary classifier is trained to detect one specific non-healthy condition. The algorithm analyzed in the present work expands the ability of detection of this tool by classifying GI tract image snapshots into two classes, depicting haemorrhage and non-haemorrhage state. The proposed algorithm is the result of the collaboration between interdisciplinary specialists on AI and Data Analysis, Computer Vision, Gastroenterologists of four University Gastroenterology Departments of Greek Medical Schools. The data used are 195 videos (177 from non-healthy cases and 18 from healthy cases) videos captured from the PillCam<sup>(R)</sup> Medronics device, originated from 195 patients, all diagnosed with different forms of angioectasia, haemorrhages and other diseases from different sites of the gastrointestinal (GI), mainly including difficult cases of diagnosis. Our AI algorithm is based on convolutional neural network (CNN) trained on annotated images at image level, using a semantic tag indicating whether the image contains angioectasia and haemorrhage traces or not. At least 22 CNN architectures were created and evaluated some of which pre-trained applying transfer learning on ImageNet data. All the CNN variations were introduced, trained to a prevalence dataset of 50%, and evaluated of unseen data. On test data, the best results were obtained from our CNN architectures which do not utilize backbone of transfer learning. Across a balanced dataset from no-healthy images and healthy images from 39 videos from different patients, identified correct diagnosis with sensitivity 90%, specificity 92%, precision 91.8%, FPR 8%, FNR 10%. Besides, we compared the performance of our best CNN algorithm versus our same goal algorithm based on HSV colorimetric lesions features extracted of pixel-level annotations, both algorithms trained and tested on the same data. It is evaluated that the CNN trained on image level annotated images, is 9% less sensitive, achieves 2.6% less precision, 1.2% less FPR, and 7% less FNR, than that based on HSV filters, extracted from on pixel-level annotated training data.
文摘AIM:To define which segments of the gastrointestinal tract are most likely to yield angioectasias for ablative therapy. METHODS:A retrospective chart review was performed for patients treated in the Louisiana State University Health Sciences Center Gastroenterology clinics between the dates of July 1, 2007 and October 1, 2010. The selection of cases for review was initiated by use of our electronic medical record to identify all patients with a diagnosis of angioectasia, angiodysplasia, or arteriovenous malformation. Of these cases, chart reviews identified patients who had a complete evaluation of their gastrointestinal tract as defined by at least one upper endoscopy, colonoscopy and small bowel capsule endoscopy within the past three years. Patients without evidence of overt gastrointestinal bleeding or iron deficiency anemia associated with intestinal angioectasias were classified as asymptomatic and excluded from this analysis. Thirty-five patients with confirmed, bleeding intestinal angioectasias who had undergone complete endoscopic evaluation of the gastrointestinal tract were included in the final analysis. RESULTS:A total of 127 cases were reviewed. Sixtysix were excluded during subsequent screening due to lack of complete small bowel evaluation and/or lack of documentation of overt bleeding or iron deficiency anemia. The 61 remaining cases were carefully examined with independent review of endoscopic images as well as complete capsule endoscopy videos. This anal- ysis excluded 26 additional cases due to insufficient records/images for review, incomplete capsule examination, poor capsule visualization or lack of confirmation of typical angioectasias by the principal investigator on independent review. Thirty-five cases met criteria for final analysis. All study patients were age 50 years or older and 13 patients (37.1%) had chronic kidney disease stage 3 or higher. Twenty of 35 patients were taking aspirin (81 mg or 325 mg), clopidogrel, and/or warfarin, with 8/20 on combination therapy. The number and location of angioectasis was documented for each case. Lesions were then classified into the following segments of the gastrointestinal tract:esophagus, stomach, duodenum, jejunum, ileum, right colon and left colon. The location of lesions within the small bowel observed by capsule endoscopy was generally defined by percentage of total small bowel transit time with times of 0%-9%, 10%-39%, and 40%-100% corresponding to the duodenum, jejunum and ileum, respectively. Independent review of complete capsule studies allowed for deviation from this guideline if capsule passage was delayed in one or more segments. In addition, the location and number of angioectasias observed in the small bowel was further modified or confirmed by subsequent device-assisted enteroscopy (DAE) performed in the 83% of cases. In our study population, angioectasias were most commonly found in the jejunum (80%) followed by the duodenum (51%), stomach (22.8%), and right colon (11.4%). Only two patients were found to have angioectasias in the ileum (5.7%). Twenty-one patients (60%) had angioectasias in more than one location.CONCLUSION:Patients being considered for endoscopic ablation of symptomatic angioectasias should undergo push enteroscopy or anterograde DAE and reinspection of the right colon.
文摘Gastrointestinal angiodysplasias (GIADs), also called angioectasias, are the most frequent vascular lesions. Its precise prevalence is unknown since most of them are asymptomatic. However, the incidence may be increasing since GIADs affect individuals aged more than 60 years and population life expectancy is globally increasing worldwide. They are responsible of about 5% to 10% of all gastrointestinal bleeding (GIB) cases. Most GIADs are placed in small bowel, where are the cause of 50 to 60% of obscure GIB diagnosed with video capsule endoscopy. They may be the cause of fatal severe bleeding episodes;nevertheless, recurrent overt or occult bleeding episodes requiring repeated expensive treatments and disturbing patient’s quality-of-life are more frequently observed. Diagnosis and treatment of GIADs (particularly those placed in small bowel) are a great challenge due to insidious disease behavior, inaccessibility to affected sites and limitations of available diagnostic procedures. Hemorrhagic causality out of the actively bleeding lesions detected by diagnostic procedures may be difficult to establish. No treatment guidelines are currently available, so there is a high variability in the management of these patients. In this review, the epidemiology and pathophysiology of GIADs and the status in the diagnosis and treatment, with special emphasis on small bowel angiodysplasias based on multiple publications, are critically discussed. In addition, a classification of GIADs based on their endoscopic characteristics is proposed. Finally, some aspects that need to be clarified in future research studies are highlighted.
文摘Small bowel vascular lesions, including angioectasia (AE), Dieulafoy’s lesion (DL) and arteriovenous malformation (AVM), are the most common causes of obscure gastrointestinal bleeding. Since AE are considered to be venous lesions, they usually manifest as a chronic, well-compensated condition. Subsequent to video capsule endoscopy, deep enteroscopy can be applied to control active bleeding or to improve anemia necessitating blood transfusion. Despite the initial treatment efficacy of argon plasma coagulation (APC), many patients experience re-bleeding, probably because of recurrent or missed AEs. Pharmacological treatments can be considered for patients who have not responded well to other types of treatment or in whom endoscopy is contraindicated. Meanwhile, a conservative approach with iron supplementation remains an option for patients with mild anemia. DL and AVM are considered to be arterial lesions;therefore, these lesions frequently cause acute life-threatening hemorrhage. Mechanical hemostasis using endoclips is recommended to treat DLs, considering the high re-bleeding rate after primary APC cauterization. Meanwhile, most small bowel AVMs are large and susceptible to re-bleeding therefore, they usually require surgical resection. To achieve optimal diagnostic and therapeutic approaches for each type of small bowel lesion, the differences in their epidemiology, pathology and clinical presentation must be understood.
文摘Continuous-flow left ventricular assist devices(CF-LVADs)have significantly improved outcomes for patients with end-stage heart failure when used as a bridge to cardiac transplantation or,more recently,as destination therapy.However,its implantations carries a risk of complications including infection,device malfunction,arrhythmias,right ventricular failure,thromboembolic disease,postoperative and nonsurgical bleeding.A significant number of left ventricular assist devices(LVAD)recipients may experience recurrent gastrointestinal hemorrhage,mainly due to combination of antiplatelet and vitamin K antagonist therapy,activation of fibrinolytic pathway,acquired von Willebrand factor deficiency,and tendency to develop small intestinal angiodysplasias due to increased rotary speed of the pump.Gastrointestinal bleeding in LVAD patients remains a source of increased morbidity including the need for blood transfusions,extended hospital stays,multiple readmissions,and overall mortality.Management of gastrointestinal bleeding in LVAD patients involves multidisciplinary approach in stabilizing the patients,addressing risk factors and performing structured endoluminal evaluation with focus on upper gastrointestinal tract including jejunum to find and eradicate culprit lesion.Medical and procedural intervention is largely successful and universal bleeding cessation occurs in transplanted patients.
文摘Splenic rupture is a rare complication of diagnostic and therapeutic gastrointestinal endoscopy procedures.Herein,we report for the first time a case of splenic rupture following therapeutic retrograde double-balloon enteroscopy,which occurred in an 85-year-old man who was treated for recurrent mid-intestinal bleeding that resulted from ileal angioectasia.This patient promptly underwent an operation and eventually recovered.
文摘AIM: To determine the test characteristics of community based video capsule endoscopy (VCE) in patients undergoing sequential VCE and double balloon enteroscopy (DBE). METHODS: Eighty-nine patients (34 females, 55 males, mean age 66) who underwent both VCE and DBE from 2008-2010 were retrospectively reviewed. Lesions detected at VCE were categorized. Capsule directed DBE followed and included 44 antegrade, 11 retrograde and 34 combined antegrade and retrograde procedures. Lesions detected were compared utilizing the McNemar's test. RESULTS: Angioectasia detection with VCE was 25% and with DBE 35% (P < 0.03) with a calculated sensitivity and specificity of 58% and 93% respectively. Polyps were detected by VCE in 22% and in DBE 20%, (P = 0.6), with a sensitivity and specificity for VCE of 61% and 87%. Small bowel diverticula were only seen in 1% of VCE but in 12% of DBE patients (P < 0.002) with a calculated sensitivity and specificity of VCE of 9% and 100%. CONCLUSION: VCE would be moderately sensitiveand specific overall with considerable variation by lesion. Furthermore, VCE cannot be relied upon to diagnose small bowel diverticula.
文摘To date,limited research has been carried out in developing methods and materials that offer three-dimensional(3-D) representation of the digestive tract.In the field of capsule endoscopy(CE),hardware approaches have been developed that provide real time both 3-D information and texture using an infrared projector and a complementary metal oxide semiconductor camera.The major drawbacks of this system are its size,power consumption and packaging issues.A software approach to approximate a 3-D representation of digestive tract surface utilising current CE technology has been proposed.The algorithm utilizes the Shape from Shading technique and seem to provide promising results for polypoid structures and angioectasias.Further clinical evaluation is currently under way.