Duodenogastric Reflux Research Articles

Immunohistochemical analysis of protease activated receptor-2 (PAR2) and cyclooxygenase-2 (COX2) co expression in Barrett esophagus

Our previous results suggested that the metaplastic process resulting in Barrett's esophagus is considered as a regenerative answer to mixed duodenogastric reflux. We also established that PAR2 is expressed on the metaplastic cells, and the expression showed correlation with the histological stage of the disease. Furthermore we demonstrated that COX2 similarly correlated with the reflux severity.

Spontaneous clearance of Helicobacter pylori after pylorus-preserving gastrectomy for gastric cancer

Residual mucosa in the gastric stump after pylorus-preserving gastrectomy (PPG) is considered a risk factor for the development of gastric stump carcinoma (GSC). Duodenogastric reflux (DGR) and Helicobacter pylori (H. pylori) infection are suspected to contribute to the development of GSC. The aim of this study was to investigate the prevalence of H. pylori in the residual stomach after PPG for gastric cancer and to assess factors associated with the presence of H. pylori. We investigated 72 patients who had undergone PPG at least 1 year prior to the study and were confirmed to be positive for H. pylori infection on presurgical endoscopic biopsy. The extent of DGR, the prevalence of H. pylori infection based on H. pylori stool antigen (HpSA) tests and the severity of gastritis were analyzed in these post-PPG patients. None of the patients had DGR, as shown by (99m)Tc-PMT. Of the 72 post-PPG patients, 33 (46%) were positive for HpSA. The prevalence of H. pylori infection was significantly lower after surgery than before surgery. The endoscopic severity of remnant gastritis, as well as histological inflammation and activity, were higher in H. pylori-positive patients than in H. pylori-negative patients. In conclusion, some patients who undergo PPG and are negative for DGR experience spontaneous clearance of H. pylori infection.

Weighted cross‐correlation based variational optical flow for gastric flow analysis in ultrasonic videos

Estimating the fluid motion in ultrasonic videos is a crucial step in the analysis of duodenogastric reflux. Severe image noise and illumination changes in the pyloric region (the region of interest) challenge the accurate estimation of gastric flow. In this paper, the authors propose an illumination-robust optical flow method based on the weighted cross-correlation. Cross-correlation was combined with the variational optical method framework as an illumination-robust local feature identifier. In consideration of accuracy near edges, they constructed visual similarity weights according to the characteristics of ultrasonic images. A processing procedure containing coarse-to-fine step and refinement was designed to get the final results. They tested the proposed method on synthetic and real ultrasonic images and compared it with other three optical flow methods. For quantitative evaluation, two metrics of angular and amplitude error were used. The synthetic results demonstrate that the proposed method performs better on ultrasonic images, with angular error of 4.1° and amplitude error of 3.3%. In qualitative comparison, the proposed method kept the motion field smooth in the homogeneous region while preserving edge information. When they used the results of the proposed method to judge the gastric flow direction, the automatic judgments agreed well with visual observation. The proposed method is a good tool for image velocimetry in ultrasonic images. It provides promising results to estimate the motion of gastric flow in ultrasonic videos.

Barrett-Ösophagus

Whereas attention in the past has been focused on goblet cells as the primary marker for Barrett's esophagus (BE), the recent change in the definition now includes the non-goblet cell columnar cell-lined esophagus. In the present study the histological features of neoplasia of the lower esophagus and esophago-gastric junction in a German cohort were examined using immunohistochemical staining for MUC, CD10, intestinal and gastric type major tight junction proteins (claudins). Experimental studies using rat duodenogastric content reflux models have also been performed and data show that most neoplastic lesions of the esophageal glands in humans express gastric mucin phenotypes. Cardiac type mucosa was the main histological type in the surrounding mucosa of neoplastic lesions; however, most cardiac type mucosa has intestinal type tight junction proteins. BE with goblet cells has been reported to originate from stem cells located in the basal layer of esophageal squamous cell epithelium in previous models. However, the cardiac type mucosa seems to develop from the site of the stomach and not from the basal layer of esophageal squamous cell epithelium according to our model.

Comparative evaluation of intragastric bile acids and hepatobiliary scintigraphy in the diagnosis of duodenogastric reflux

To assess the diagnostic value of a combination of intragastric bile acids and hepatobiliary scintigraphy in the detection of duodenogastric reflux (DGR). The study contained 99 patients with DGR and 70 healthy volunteers who made up the control group. The diagnosis was based on the combination of several objective arguments: a long history of gastric symptoms (i.e., nausea, epigastric pain, and/or bilious vomiting) poorly responsive to medical treatment, gastroesophageal reflux symptoms unresponsive to proton-pump inhibitors, gastritis on upper gastrointestinal (GI) endoscopy and/or at histology, presence of a bilious gastric lake at > 1 upper GI endoscopy, pathologic 24-h intragastric bile monitoring with the Bilitec device. Gastric juice was aspirated in the GI endoscopy and total bile acid (TBA), total bilirubin (TBIL) and direct bilirubin (DBIL) were tested in the clinical laboratory. Continuous data of gastric juice were compared between each group using the independent-samples Mann-Whitney U-test and their relationship was analysed by Spearman's rank correlation test and Fisher's linear discriminant analysis. Histopathology of DGR patients and 23 patients with chronic atrophic gastritis was compared by clinical pathologists. Using the Independent-samples Mann-Whitney U-test, DGR index (DGRi) was calculated in 28 patients of DGR group and 19 persons of control group who were subjected to hepatobiliary scintigraphy. Receiver operating characteristic curve was made to determine the sensitivity and specificity of these two methods in the diagnosis of DGR. The group of patients with DGR showed a statistically higher prevalence of epigastric pain in comparison with control group. There was no significant difference between the histology of gastric mucosa with atrophic gastritis and duodenogastric reflux. The bile acid levels of DGR patients were significantly higher than the control values (Z: TBA: -8.916, DBIL: -3.914, TBIL: -6.197, all P < 0.001). Two of three in the DGR group have a significantly associated with each other (r: TBA/DBIL: 0.362, TBA/TBIL: 0.470, DBIL/TBIL: 0.737, all P < 0.001). The Fisher's discriminant function is followed: Con: Y = 0.002TBA + 0.048DBIL + 0.032TBIL - 0.986; Reflux: Y = 0.012TBA + 0.076DBIL + 0.089TBIL - 2.614. Eighty-four point zero five percent of original grouped cases were correctly classified by this method. With respect to the DGR group, DGRi were higher than those in the control group with statistically significant differences (Z = -5.224, P < 0.001). Twenty eight patients (59.6%) were deemed to be duodenogastric reflux positive by endoscopy, as compared to 37 patients (78.7%) by hepatobiliary scintigraphy. The integrated use of intragastric bile acid examination and scintigraphy can greatly improve the sensitivity and specificity of the diagnosis of DGR.

The role of duodenogastric reflux in formation of precarcinogenic gastric lesions: An experimental study

Duodenogastric reflux, commonly encountered as an aftermath of gastroenteroanastomosis, with or without gastric resection (Billroth I, Billroth II), vagotomy and pyloroplastic surgery, is known to cause inflammatory-dystrophic-metaplastic lesions of gastric mucosa. Our objective was to determine the effects of surgery-induced duodenogastric reflux on the development of precarcinogenic lesions or carcinoma in correlation with the reflux duration. The experiment was performed on three groups of Wistar rats with 1) Billroth II-induced reflux surgery, 2) resection of the Rouxr-en-Y type reconstruction, and 3) control group with no resection. The aim of the experiment was to study the effects ofduodenogastric reflux on the rat gastric mucosa in correlation with two different types of gastroenteroanastomosis 8, 16 and 24 weeks after the surgery. In Billroth II group, hyperplastic changes were observed as early as in week 16. Statistically significant results were recorded in week 24, with 6.7% of metaplastic alterations, including dysplasia of all three degrees, dominantly severe dysplasia in 66.67%, early carcinoma in 20% and gastric carcinoma in 6.67%. In the Roux-en-Y group, gastric mucosa remained predominantly normal (60%), with somewhat increased frequency ofgastritis and dysplasia in week 24. In the control group, the finding of normal gastric mucosa was constant. The experiment confirms that direct contact of duodenal juice with gastric mucosa associated with Billroth II resection causes precarcinogenic lesions. Development of adenocarcinoma caused solely by duodenogastric reflux, excluding a carcinogenic agent is possible 20 weeks after the experiment--earlier than suggested by previous researchers.

IS GASTROESOPHAGEAL REFLUX DISEASE INFLUENCED BY DUODENOGASTRIC REFLUX ?

It is well known that the gastroesophageal reflux is a frequent disease in medical practice. A lot of factors are involved in its pathogenesis. The aim of our study was to find out if the duodenogastric reflux is one of these factors. We also looked for the pathological conditions associated with duodenogastric reflux. We studied a lot of 59c (30c females and 29c males) with ages between 39 and 54 years old suffering from gastroesophageal disease. Material and methods: EDS examination and abdominal ultrasound were done and we calculated the score of gastroesophageal reflux by GERD Q method. Results and discussion: Our results show the high frequency of cholesterolosis (45.7%). All of these cases presented duodenogastric reflux, which means that biliary disease can be one of the causes of the gastroesophageal reflux. Conclusion: The duodenogastric reflux aggravated gastroesophageal reflux and induced esophagitis in 50% of cases.

REVIEW ARTICLE; DUODENO-GASTRO-ESOPHAGEAL REFLUX COMBINED AND ISOLATED

Barrett’s esophagus is the chief risk factor for esophageal adenocarcinoma. Reflux of gastric acid has long been related to the development of esophagitis and Barrett’s esophagus, but the role of duodenal contents is controversial. We review the literature on the role of duodenal contents in the development of esophagitis, Barrett’s esophagus and adenocarcinoma in addition to the role of acid suppressant therapy in the development or prevention of these changes. A computer-based search of the literature using the terms "Bilirubin, Barrett, Bile Reflux, duodeno-gastric reflux and oesophagus/esophagus" was performed. The role of bile and other constituents of duodenal refluxate were examined. Techniques for identifying non-acid reflux were also reviewed, as were the role of pH, medication and surgery in modulating disease severity. Complicated Barrett’s esophagus is associated with increased exposure to gastric and duodenal refluxate. Biological effect of bile acids depends on the conjugation status, the pH of the milieu and the pKa of bile acids. While Proton Pump Inhibitors reduce the levels of DGER, they also produce changes in gastric and lower esophageal pH that activate different bile acids at different pH levels resulting in unexpected injury. Conjugated bile acids are harmful in acidic environment while unconjugated bile acids are harmful at neutral pH environment. An overlap of toxicity among conjugated and unconjugated bile acids occurs between strongly acidic and neutral pH levels. Normalisation of gastric and duodenal refluxate should ideally be the goal of treatment.

Significance of ultrasonic measurement of pyloric canal diameter in diagnosis of duodenogastric reflux

Significance of ultrasonic measurement of pyloric canal diameter in diagnosis of duodenogastric reflux

胆道再建後の胆汁排泄動態およびduodenogastric reflux について

胆道再建後の胆汁排泄動態およびduodenogastric reflux について

Endotoxin-induced changes in phospholipid dynamics of the stomach

BackgroundThe gastric mucosa is protected in part by a hydrophobic layer of phosphatidylcholine (PC) that overlies the mucus gel on the stomach. Endotoxin treatment (i.e., lipopolysaccharide [LPS]) results in an apparent disruption of this layer, as evidenced by a reduction in surface hydrophobicity and an increase in transmural permeability. The current studies compared PC and lyso-PC levels in mucus and gastric mucosa before and after LPS treatment, and examined potential mechanisms for surface phospholipid changes. MethodsRats were administered LPS (5 mg//kg, intraperitoneally) and samples were collected after 5 h for analysis of PC and its primary degradant, lyso-PC, in the loosely and firmly adherent mucus layers and the mucosa. The dependence of LPS-induced effects on gastric alkalinization, PC synthetic activity, and intestinal reflux material was assessed. ResultsThe gastric contents after LPS, which also contained duodenal reflux material, had greatly increased amounts of PC and lyso-PC. The firmly adherent mucus layer was unchanged. The gastric mucosa after LPS revealed significant reductions of PC levels and no change in lyso-PC content. These phospholipid changes were not caused by alkalinization of the stomach or altered PC synthesis. Prevention of duodenogastric reflux by pylorus ligation blocked the LPS-induced increase in luminal lyso-PC and the reduction in mucosal PC. ConclusionsLPS appears to induce a release of PC from gastric mucosa into the lumen, along with degradation of PC to lyso-PC, without an effect on PC synthesis. Component(s) of intestinal reflux material appear to be required for these effects. The lowered PC levels in gastric mucosa after LPS may contribute to reduced barrier properties of this tissue.

Chronic Dyspepsia with a Negative Workup: Consider an Early Cholecystokinin-HIDA Scan

Purpose: Dyspeptic symptoms are common in the general population, leading to frequent visits to the doctor and repeated diagnostic tests. Quite often no evidence of structural disease is found that would explain the symptoms. Cholecystokinin-HIDA scan (CCK-HIDA) provides a quantitative method for assessing gallbladder contraction and calculation of the gallbladder ejection fraction (GBEF). We hypothesize that CCK-HIDA would identify a functional gallbladder disorder as the cause of dyspeptic symptoms in a significant percentage of patients with previously negative workup. Methods: We performed a retrospective analysis of patients who underwent CCK-HIDA at our hospital between October 2009 and October 2011. We included patients whose abdominal ultrasound/CT scan, upper and lower GI endoscopy did not provide an explanation for their symptoms. We excluded patients with cholelithiasis/choledocholithiasis, previous sphincterotomy, any biliary surgery, and patients taking prokinetic medications. We collected demographic data, information regarding clinical presentation, abdominal ultrasound and/or CT scan, esogastroduodenoscopy, colonoscopy and CCK-HIDA; we documented GBEF, the presence of reflux into the gallbladder, and duodenogastric reflux. CCK-HIDA was performed according to a standardized protocol, with GBEF of 35% and below being considered abnormal. Data were analyzed using SPSS; parametric methods were employed. Results are shown as median (range). Results: Eighty-six consecutive patients underwent CCK-HIDA in our hospital during the above period; 63 patients (20 M/43 F) met the inclusion criteria; 42 of these patients (13 M/29 F) had evidence of negative GI workup as described above and were included in the analysis. Patients' median age was 52 (range 21-89). Forty-seven percent of patients complained of right upper quadrant pain at presentation; 23% had epigastric pain. Twenty-three out of the 42 patients (55%) had a low GBEF as defined above; median GBEF in this group was 19 (range 3-35). Five patients showed reflux into the gallbladder, or duodenogastric reflux. There was no significant difference between the patients with low and those with normal GBEF in terms of age (p=0.875) or gender (p=0.555). No correlation was found between age and GBEF overall. Conclusion: A significant percentage of patients with dyspeptic symptoms and otherwise negative GI workup exhibit a low GBEF. This is not associated with a particular age or gender. Employment of the CCK-HIDA early in the diagnostic process might help in elucidating faster the etiology of these complaints.

Reactive gastropathy is associated with inflammatory conditions throughout the gastrointestinal tract

The epidemiology of reactive gastropathy and its relationship with other conditions of the gastrointestinal tract associated with NSAID use have not been evaluated. To test the hypothesis that if reactive gastropathy shares common aetiological factors with these conditions, the analysis of a large cohort would unveil associations. We queried a national pathology database for subjects with a diagnosis of reactive gastropathy; controls were patients with normal gastric biopsies. We also extracted diagnoses of H. pylori infection, intestinal metaplasia, duodenal lymphocytosis, duodenitis, ileitis, microscopic colitis and focal colitis. Of 504011 patients with gastric biopsies, 69101 had oesophageal, 166134 duodenal, 13010 ileal and 83334 colonic biopsies. Reactive gastropathy was diagnosed in 15.6% of patients, H. pylori infection in 10.3% and normal gastric mucosa in 16.3%. Reactive gastropathy was evenly distributed across the US and increased from 2.0% in the first decade of life to>20% in octogenarians. Compared with controls, reactive gastropathy was significantly associated with Barrett's mucosa (OR 1.21 95% CI 1.16-129); duodenitis (OR 1.36; 95% CI 1.28-1.44); duodenal intraepithelial lymphocytosis (OR 1.25; 95% CI 1.13-1.39); active ileitis (OR 1.88; 95% CI 1.47-2.40); focal active colitis (OR 1.57; 95% CI 1.33-1.86); and collagenous colitis (OR 1.50; 95% CI 1.12-2.03). Reactive gastropathy, a common histopathological feature of the stomach, shows an age-dependent rise and is associated with changes of the digestive tract believed to be caused by NSAID use or duodenogastric reflux. However, a large fraction of reactive gastropathy remains unexplained; its frequent occurrence merits further efforts at elucidating its aetiology.

Conditional Expression of Wnt9b in Six2-Positive Cells Disrupts Stomach and Kidney Function

During kidney development, canonical Wnt signaling activates differentiation, while the transcription factor Six2 maintains the progenitor pool. These opposing signals help to regulate nephron formation and ensure the full complement of nephrons are formed. Since these two factors control differing fates in kidney mesenchyme, we hypothesized that overexpression of Wnt9b in Six2-expressing cells would disrupt kidney formation and may alter cell differentiation decisions in other tissues. We created a transgenic mouse that conditionally expressed the canonical Wnt ligand in the developing kidney, Wnt9b. The transgene is activated by cre recombinase and expresses GFP. We first tested its biological activity using Hoxb7-cre and found that transgenic Wnt9b was capable of inducing differentiation genes and of rescuing kidney development in Wnt9b−/− homozygous deficient mice. In contrast, expression of Wnt9b in cells using Six2-cre caused gastrointestinal distress and severe renal failure in adult mice. Transgenic kidneys had numerous cystic tubules and elevated creatinine values (0.652±0.044) compared to wild-type mice (0.119±0.002). These animals also exhibited a malformed pyloric sphincter, duodenogastric reflux, and a transformation of the distal stomach into proximal fate. The gene expression changes observed for the Wnt9b:EGFP transgene were compared to a stabilized β-catenin allele to determine that Wnt9b is activating the canonical Wnt pathway in the tissues analyzed. These results demonstrate that expression of Wnt9b in Six2-positive cells disrupts cell fate decisions in the kidney and the gastrointestinal tract.

식도 재건 수술에 있어 유문 성형과 식도 접합 경로에 따른 음식물 역류 현상 연구

In this study, duodenogastric reflux has been investigated according to pyloroplasty and the path of the gastric tube in esophageal reconstruction. The paths of the gastric graft (front and rear paths) were determined from the CT images of ten patients, and the gastric tube model was constructed using an RP technique. The gastric tubes were connected to the pylorus models with and without pyloroplasty. Various distal pressures and pulse widths were applied, and the volume and maximum height of the refluxate were measured. The results show that the volume and height of the refluxate increase with the distal pressure, and the front path leads to a smaller volume and lesser height of the refluxate than the rear path if pyloroplasty is conduced. The volume of the refluxate is markedly increased by a larger pulse width, but its effect on the maximum height depends on whether pyloroplasty is conducted.

Patients with partial gastrectomy and Barrett esophagus are in higher risk to develop esophageal adenocarcinoma than those with Barretts without gastrectomy.

Duodenogastric reflux is a possible risk factor for esophageal adenocarcinoma (CA) development. Gastric surgery that destroys or distorts the pylorus is a good model to study the effects of duodenogastric reflux. To define the consequences of gastrectomy in patients with Barrett esophagus (BE). Records of all BE/CA patients examined in Blackpool-Wyre-Fylde area were reviewed. All surviving patients completed validated questionnaires. Gastrectomy was more prevalent in CA patients (14 (3.6%) BE vs. 15 (13.3%) CA, p=0.0002). Partial gastrectomy was more prevalent in CA patients, (7 (1.8%) BE vs. 10 (8.8%) CA, p=0.0004), while there was no difference in total gastrectomy between the two groups. Persistence of H. pylori infection after gastrectomy and smoking were more frequent among CA patients with gastrectomy. Mean follow-up time in patients with prior gastrectomy was 78 (SD=76.4) months for BE patients and 119.3 (SD=72.9) months for CA patients (p=0.07). In logistic regression analysis gastrectomy, in addition to old age, long-term reflux, absence of hiatal hernia and H. pylori infection were risk factors for CA. Gastrectomy and especially partial gastrectomy was more prevalent in CA patients.

Usefulness of Pyloric Reconstruction Without Compromising Curative Resection in Gastric Cancer Treatment

IntroductionWe herein report the short-term results of the newly developed modified technique of Billroth I (modified B-I; pylorus reconstruction) that prevents duodenogastric reflux (DGR) and remnant gastritis after distal gastrectomy. Patients and MethodsDistal gastrectomy with this technique was performed in 20 patients (age, 41 to 86 years [mean, 68.5±11.8 years], male/female = 12:8) with gastric cancer from June 2006 through December 2009. These patients were compared with another 20 patients who underwent conventional B-I after distal gastrectomy (age, 41 to 85 years [mean, 69.3±8.69 years], male/female = 11:9). The side effects of gastric surgery evaluated in this study were the degree of remnant gastritis, the presence of dumping syndrome, and the degree of weight loss. ResultsBy gastrografin contrast imaging on the fifth day after pylorus reconstruction, the remnant stomach was not dilated and gastrografin flowed physiologically to the duodenum without backward reflux into the remnant stomach. By gastroscopy at 6 months after the operation, DGR and the degree of remnant gastritis after pylorus reconstruction was lower than those of conventional B-I (P = 0.00068). The bile acid concentration of remnant gastric juice of pylorus reconstruction was lower than that of conventional B-I (55.5±93.5 vs. 1,369.5 ± 2,502.1 μmol/L, P = 0.0415). Weight loss at 1 year after distal gastrectomy was less in pylorus reconstruction compared with conventional B-I (6.2 ± 5.2% vs. 9.8 ± 8.7%, P = 0.0725). ConclusionPylorus reconstruction is a simple and safe anastomotic technique that reduces the side effects of B-I reconstruction.

Therapeutic efficacy of acotiamide in patients with functional dyspepsia based on enhanced postprandial gastric accommodation and emptying: randomized controlled study evaluation by real‐time ultrasonography

Improvement in subjective symptoms has been reported in functional dyspepsia (FD) patients administered with acotiamide. Improvement was confirmed in meal-related symptoms, such as postprandial fullness, upper abdominal bloating, and early satiety. We examined the mechanism underlying the effects of acotiamide on gastric accommodation reflex (GAR) and gastroduodenal motility in FD patients. Thirty-four FD patients (mean age, 40.4 years) were examined ultrasonographically before and after 14-18 days of acotiamide (100 mg t.i.d.) or placebo administration. To assess GAR, expansion rate in cross-sectional area of the proximal stomach was measured after every 100-mL ingestion, using a straw, of up to 400 mL of a liquid meal (consommé soup, 13.1 kcal; 400 mL) in a supine position. Next, we measured gastric emptying rate (GER), motility index (MI, antral contractions), and reflux index (RI, duodenogastric reflux) to assess gastroduodenal motility. Patients also completed a survey based on the seven-point Likert scale both before and after drug administration. Of the 37 cases, 19 and 18 were administered with acotiamide and placebo A respectively, significant difference was observed in GAR between the acotiamide and placebo groups (21.7%vs 4.4%) after 400 mL ingestion. GER significantly accelerated after treatment in the acotiamide group (P = 0.012), no significant differences were observed in MI and RI between the two groups. Improvement rates were 35.3 and 11.8% for the acotiamide and placebo groups. Acotiamide significantly enhances GAR and GER in FD patients. Acotiamide may have therapeutic potential for FD patients.

Histological features of the gastric mucosa in children with primary bile reflux gastritis

BackgroundBile reflux is one of the primary factors involved in the pathogenesis of gastric mucosal lesions in patients with chronic gastritis; however, little is known about the exact histological features of bile reflux and its contributions to gastric mucosal lesions in this disease, especially in children with primary bile reflux gastritis (BRG). The aim of this study was to investigate the classic histological changes of the gastric mucosa in children with primary BRG.MethodsThe Bilitec 2000 was used for 24 h monitoring of gastric bile in 59 children with upper gastrointestinal symptoms. The histological characteristics of the gastric mucosa were examined and scored.ResultsThirteen of the 59 patients had a helicobacter pylori infection and were excluded; therefore, 46 cases were included in this study. The positive rate of pathological duodenogastric reflux was significantly higher in patients with foveolar hyperplasia than those without foveolar hyperplasia; however, the rate was significantly lower in patients with vascular congestion than those without vascular congestion. The longest reflux time and the total percentage time of bile reflux were significantly lower in patients with vascular congestion than those without vascular congestion. A total of 9 types of histological changes were analyzed using a binary logistic regression. Foveolar hyperplasia and vascular congestion in the superficial layer became significant variables in the last step of the stepwise regression.ConclusionsFoveolar hyperplasia was associated with the severity of bile reflux, suggesting that it is a histological feature of primary BRG in children, while vascular congestion may be a protective factor.

Tracking Pylorus in Ultrasonic Image Sequences With Edge-Based Optical Flow

Tracking pylorus in ultrasonic image sequences is an important step in the analysis of duodenogastric reflux (DGR). We propose a joint prediction and segmentation method (JPS) which combines optical flow with active contour to track pylorus. The goal of the proposed method is to improve the pyloric tracking accuracy by taking account of not only the connection information among edge points but also the spatio-temporal information among consecutive frames. The proposed method is compared with other four tracking methods by using both synthetic and real ultrasonic image sequences. Several numerical indexes: Hausdorff distance (HD), average distance (AD), mean edge distance (MED), and edge curvature (EC) have been calculated to evaluate the performance of each method. JPS achieves the minimum distance metrics (HD, AD, and MED) and a smaller EC. The experimental results indicate that JPS gives a better tracking performance than others by the best agreement with the gold curves while keeping the smoothness of the result.