Magnetic Resonance Imaging Including Magnetic Resonance Cholangiopancreatography for Tumor Localization and Therapy Planning in Malignant Hilar Obstructions

International Nuclear Information System (INIS)

Haenninen, E.L.

2005-01-01

PURPOSE: To assess image quality and overall accuracy of magnetic resonance imaging (MRI), including two magnetic cholangiopancreatography (MRCP) techniques, for the diagnostics and preoperative work-up of malignant hilar obstructions. MATERIAL AND METHODS: Thirty-one patients with malignant hilar obstructions (hilar cholangiocarcinoma, n=30; hepatocellular carcinoma, n=1) received MRCP by two techniques (single-shot thick-slab and multisection thin-slice MRCP) and unenhanced and contrast material-enhanced MRI. MR assessment included the evaluation of image quality and visualization of bile ducts (5-point scale), and the classification of tumor status. MR results were subsequently correlated with the results from surgery and pathology. RESULTS: The maximum intensity projections of multisection thin-slice MRCP had significantly more artifacts compared to MRCP in the single-shot thick-slab technique, and overall image quality of single-shot thick-slab MRCP was rated significantly superior compared to multisection thin-slice MRCP (4.4 ± 0.7 and 4.1 ± 0.9, respectively). Moreover, ductal visualization of different parts of the biliary system was rated superior with single-shot thick-slab MRCP. In contrast, the original data from multisection thin slice MRCP facilitated visualization of periductal lesions and adjacent structures. Overall MR accuracy for the assessment of tumor status, periductal infiltration, and lymph node metastases was 90%, 87%, and 66%, respectively. CONCLUSION: For evaluation of malignant hilar obstructions, MRCP by the single-shot thick-slab technique had superior image quality and fewer artifacts; in contrast, besides sole biliary visualization, multisection MRCP depicted complementary adjacent parenchymal and periductal structures. We therefore recommend MRI, with a combination of both MRCP techniques, for the diagnostic work-up and therapy planning of malignant hilar obstructions

Inpatient magnetic resonance cholangiopancreatography: does it increase the efficiency in emergency hepatopancreaticobiliary surgery services?

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Milburn, J A; Bailey, J A; Dunn, Wk; Cameron, I C; Gomez, D S

2017-04-01

INTRODUCTION Magnetic resonance cholangiopancreatography (MRCP) is commonly used to evaluate the biliary tree, although indications for patients who require inpatient imaging are not fully defined. The aim of this study was to evaluate inpatient MRCP performed on surgical patients and to devise a treatment pathway for these patients. MATERIAL AND METHODS All adult inpatient MRCP examinations between January 2012 and December 2013 were reviewed. Demographic, clinical and radiological data were collated. RESULTS During the study period, 271 inpatient MRCP were requested, of which 234 examinations were included. The majority of patients were female (n=140) and the median age was 63 years (range 16-93 years). Surgical admissions accounted for 171 (73%) of cases. Indications for inpatient MRCP include gallstone-related complications (n=173; 74%), malignant process (n=17; 7%) and other indications (n=44; 19%). Overall, inpatient MRCP led to further inpatient interventions in 22% (gallstone group, n=32, 18%; patients with malignancy, n=8, 47%; other indications, n=12, 27%). The median duration of inpatient MRCP from request to examination was 2 days (range 0-15 days) and median reporting after examination was 1 day (range 0-14 days). DISCUSSION AND CONCLUSION Improved access and timely reporting of iMRCP may reduce length of hospital stay. Inpatient MRCP also led to further inpatient interventions, in particular, in patients with malignancy.

Cost-effectiveness analysis of endoscopic ultrasound versus magnetic resonance cholangiopancreatography in patients with suspected common bile duct stones.

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Stephen Morris

Full Text Available Patients with suspected common bile duct (CBD stones are often diagnosed using endoscopic retrograde cholangiopancreatography (ERCP, an invasive procedure with risk of significant complications. Using endoscopic ultrasound (EUS or Magnetic Resonance CholangioPancreatography (MRCP first to detect CBD stones can reduce the risk of unnecessary procedures, cut complications and may save costs.This study sought to compare the cost-effectiveness of initial EUS or MRCP in patients with suspected CBD stones.This study is a model based cost-utility analysis estimating mean costs and quality-adjusted life years (QALYs per patient from the perspective of the UK National Health Service (NHS over a 1 year time horizon. A decision tree model was constructed and populated with probabilities, outcomes and cost data from published sources, including one-way and probabilistic sensitivity analyses.Using MRCP to select patients for ERCP was less costly than using EUS to select patients or proceeding directly to ERCP ($1299 versus $1753 and $1781, respectively, with similar QALYs accruing to each option (0.998, 0.998 and 0.997 for EUS, MRCP and direct ERCP, respectively. Initial MRCP was the most cost-effective option with the highest monetary net benefit, and this result was not sensitive to model parameters. MRCP had a 61% probability of being cost-effective at $29,000, the maximum willingness to pay for a QALY commonly used in the UK.From the perspective of the UK NHS, MRCP was the most cost-effective test in the diagnosis of CBD stones.

Magnetic resonance cholangiopancreatography in the diagnosis of pancreas divisum: a systematic review and meta-analysis.

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Rustagi, Tarun; Njei, Basile

2014-08-01

This study aimed to perform a structured meta-analysis of all eligible studies to assess the overall diagnostic use of magnetic resonance cholangiopancreatography (MRCP) alone or with secretin enhancement (secretin-enhanced MRCP [S-MRCP]) in the detection of pancreas divisum. Two authors independently performed a comprehensive search of PubMed, MEDLINE, and the Cochrane Library from inception to September 2013. Studies were included if they allowed construction of 2 × 2 contingency tables of MRCP and/or S-MRCP compared with criterion standard. DerSimonian-Laird random effect models were used to estimate the pooled sensitivity, specificity, specificity, and quantitative receiver operating characteristics. Of 51 citations, 10 studies with 1474 patients were included. Secretin-enhanced MRCP had a higher overall diagnostic performance than MRCP (S-MRCP: pooled sensitivity, 86% [95% confidence interval (CI), 77%-93%]; specificity, 97% [95% CI, 94%-99%]; and area under the curve, 0.93 ± 0.056 compared with MRCP: sensitivity, 52% [95% CI, 45%-59%]; specificity, 97% [95% CI, 94%-99%]; and area under the curve, 0.76 ± 0.104). Pooled diagnostic odds ratios were 72.19 (95% CI, 5.66-938.8) and 23.39 (95% CI, 7.93-69.02) for S-MRCP and MRCP, respectively. Visual inspection of the funnel plot showed low potential for publication bias. Secretin-enhanced MRCP has a much higher diagnostic accuracy than MRCP and should be preferred for diagnosis of pancreas divisum.

Does secretin add value in pediatric magnetic resonance cholangiopancreatography?

International Nuclear Information System (INIS)

Trout, Andrew T.; Podberesky, Daniel J.; Serai, Suraj D.; Towbin, Alexander J.; Ren, Yan; Altaye, Mekebib

2013-01-01

Secretin - a hormone that stimulates pancreatic exocrine secretion - is described to improve visualization of the pancreatic duct by magnetic resonance cholangiopancreatography (MRCP). In our pediatric practice, however, we have not observed substantial benefit with the use of secretin. To determine whether secretin dilates and improves visualization of the pancreatic duct in pediatric MRCP. Retrospective evaluation of secretin-enhanced MRCPs performed over a 15-month period. One reviewer measured the pancreatic duct pre- and post-secretin and two reviewers, blinded to the administration of secretin, assessed image quality and subjective duct visibility. Similar assessments of the biliary tree served as internal controls. We reviewed 20 MRCPs in 17 children. Following secretin administration, there was a small (0.3 mm) but statistically significant increase in pancreatic duct diameter (P = 0.002) and small (<0.2 mm) but significant increase in intrahepatic bile duct diameter (P = 0.0104). On subjective review, there was no significant difference in image quality or duct visibility based on the administration of secretin. Secretin induces dilatation of the pancreatic duct but the value of that effect in pediatric MRCP is suspect given the small change in duct diameter and the lack of improvement in image quality and duct visibility. (orig.)

Pineapple juice labeled with gadolinium: a convenient oral contrast for magnetic resonance cholangiopancreatography

International Nuclear Information System (INIS)

Coppens, Emmanuel; Metens, Thierry; Winant, Catherine; Matos, Celso

2005-01-01

The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP. (orig.)

Pineapple juice labeled with gadolinium: a convenient oral contrast for magnetic resonance cholangiopancreatography

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Coppens, Emmanuel; Metens, Thierry; Winant, Catherine; Matos, Celso [Hopital Erasme, Universite Libre de Bruxelles, Department of Radiology, Division of Magnetic Resonance, Brussels (Belgium)

2005-10-01

The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP. (orig.)

A prospective pilot study: Can the biliary tree be visualized in children younger than 3 months on Magnetic Resonance Cholangiopancreatography?

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Siles, Pascale [La Timone Children' s Hospital, Department of Radiology, Marseille (France); Aschero, Audrey; Gorincour, Guillaume; Bourliere-Najean, Brigitte; Petit, Philippe [La Timone Children' s Hospital, Department of Pediatric Radiology, Marseille (France); Roquelaure, Bertrand [La Timone Children' s Hospital, Department of Pediatrics, Marseille (France); Delarue, Arnauld [La Timone Children' s Hospital, Department of Pediatric Surgery, Marseille (France)

2014-09-15

Magnetic resonance cholangiopancreatography (MRCP) could aid in the diagnosis of biliary atresia, a hepatic pathology with thin, irregular or interrupted biliary ducts. There is little published evidence of MRCP appearances in normal neonates and young infants. To assess the use of MR cholangiopancreatography in visualizing the biliary tree in neonates and infants younger than 3 months with no hepatobiliary disorder, and to assess this visibility in relationship to the child's age, weight, and sedation and fasting states. Between December 2008 and October 2010 our department performed MRI of the brain, orbits and face on 16 full-term neonates and infants. Each child was younger than 3 months (90 days) and without any hepatobiliary disorders. The children were scanned with a respiratory-gated 0.54 x 0.51 x 0.4-mm{sup 3} 3-D MRCP sequence. We used a reading grid to assess subjectively the visibility of the extrahepatic bile ducts along with extrahepatic bile duct confluence. The visibility of the extrahepatic bile duct confluence was assessed against age, weight, and sedation and fasting states. The extrahepatic bile duct confluence was seen in 10 children out of 16 (62.5%). In the neonate sub-group (corrected age younger than 30 days), the MRCP was technically workable and the extrahepatic bile duct confluence was seen in four cases out of eight (50%). This visualization was up to 75% in the subgroup older than 30 days. However, statistically there was no significant difference in visibility of the extrahepatic bile duct confluence in relationship to age, weight or MRCP performance conditions (feeding, fasting or sedation). The complete normal biliary system (extrahepatic bile duct confluence included) is not consistently visualized in infants younger than 3 months old on non-enhanced MRCP. Thus the use of MRCP to exclude a diagnosis of biliary atresia is compromised at optimal time of surgery. (orig.)

A prospective pilot study: Can the biliary tree be visualized in children younger than 3 months on Magnetic Resonance Cholangiopancreatography?

International Nuclear Information System (INIS)

Siles, Pascale; Aschero, Audrey; Gorincour, Guillaume; Bourliere-Najean, Brigitte; Petit, Philippe; Roquelaure, Bertrand; Delarue, Arnauld

2014-01-01

Magnetic resonance cholangiopancreatography (MRCP) could aid in the diagnosis of biliary atresia, a hepatic pathology with thin, irregular or interrupted biliary ducts. There is little published evidence of MRCP appearances in normal neonates and young infants. To assess the use of MR cholangiopancreatography in visualizing the biliary tree in neonates and infants younger than 3 months with no hepatobiliary disorder, and to assess this visibility in relationship to the child's age, weight, and sedation and fasting states. Between December 2008 and October 2010 our department performed MRI of the brain, orbits and face on 16 full-term neonates and infants. Each child was younger than 3 months (90 days) and without any hepatobiliary disorders. The children were scanned with a respiratory-gated 0.54 x 0.51 x 0.4-mm 3 3-D MRCP sequence. We used a reading grid to assess subjectively the visibility of the extrahepatic bile ducts along with extrahepatic bile duct confluence. The visibility of the extrahepatic bile duct confluence was assessed against age, weight, and sedation and fasting states. The extrahepatic bile duct confluence was seen in 10 children out of 16 (62.5%). In the neonate sub-group (corrected age younger than 30 days), the MRCP was technically workable and the extrahepatic bile duct confluence was seen in four cases out of eight (50%). This visualization was up to 75% in the subgroup older than 30 days. However, statistically there was no significant difference in visibility of the extrahepatic bile duct confluence in relationship to age, weight or MRCP performance conditions (feeding, fasting or sedation). The complete normal biliary system (extrahepatic bile duct confluence included) is not consistently visualized in infants younger than 3 months old on non-enhanced MRCP. Thus the use of MRCP to exclude a diagnosis of biliary atresia is compromised at optimal time of surgery. (orig.)

Clinical role of secretin loading magnetic resonance cholangiopancreatography in the patients undergoing pancreatic resection

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Shimada, Ken; Takahashi, Tsuyoshi; Yoshida, Muneki; Kakita, Akira [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine

2002-01-01

We determined factors contributing to increased signal intensity in the reconstructed jejunal loop in patients undergoing pancreatic resection, frequently observed on magnetic resonance cholangiopancreatography following intravenous injection of secretin (S/MRCP). We also evaluated the possible roles of S/MRCP in assessing the patency of pancreatojejunal anastomosis and the secretory function of the remnant pancreas. Subject were 44 patients undergoing several types of pancreatic resection. Baseline output and response to secretin of the remnant pancreas were measured after surgery. S/MRCP and pancreatic function diagnostant (PFD) tests were conducted preoperatively, and in early and late periods after surgery. Baseline pancreatic output was 1.2{+-}0.7 ml/10-min, and increased after secretin load to a maximum 9.0{+-}6.6 ml/10-min in 10 min. Signal intensity of the jejunal loop increased in 2 patients versus 40 patients (95%) during the early versus late postoperative periods. During the late period, PFD was significantly higher in patients with increased signal intensity than in those without. PFD correlated well with cumulative pancreatic output following secretin loading (r=0.820). A major factor responsible for increased signal intensity in S/MRCP of the jejunal loop was increased pancreatic output. The increase in signal intensity was a definitive sign of patent pancreatojejunal anastomosis. S/MRCP thus seems to have a potential for evaluating the secretory function of the remnant pancreas. (author)

Clinical role of secretin loading magnetic resonance cholangiopancreatography in the patients undergoing pancreatic resection

International Nuclear Information System (INIS)

Shimada, Ken; Takahashi, Tsuyoshi; Yoshida, Muneki; Kakita, Akira

2002-01-01

We determined factors contributing to increased signal intensity in the reconstructed jejunal loop in patients undergoing pancreatic resection, frequently observed on magnetic resonance cholangiopancreatography following intravenous injection of secretin (S/MRCP). We also evaluated the possible roles of S/MRCP in assessing the patency of pancreatojejunal anastomosis and the secretory function of the remnant pancreas. Subject were 44 patients undergoing several types of pancreatic resection. Baseline output and response to secretin of the remnant pancreas were measured after surgery. S/MRCP and pancreatic function diagnostant (PFD) tests were conducted preoperatively, and in early and late periods after surgery. Baseline pancreatic output was 1.2±0.7 ml/10-min, and increased after secretin load to a maximum 9.0±6.6 ml/10-min in 10 min. Signal intensity of the jejunal loop increased in 2 patients versus 40 patients (95%) during the early versus late postoperative periods. During the late period, PFD was significantly higher in patients with increased signal intensity than in those without. PFD correlated well with cumulative pancreatic output following secretin loading (r=0.820). A major factor responsible for increased signal intensity in S/MRCP of the jejunal loop was increased pancreatic output. The increase in signal intensity was a definitive sign of patent pancreatojejunal anastomosis. S/MRCP thus seems to have a potential for evaluating the secretory function of the remnant pancreas. (author)

Magnetic resonance cholangiopancreatography findings of pancreatic diseases: quantitative analysis

International Nuclear Information System (INIS)

Xu Jun; Lu Jianping; Wang Jian; Wang Fei; Liu Qi; Wang Li; Gong Jianguo; Jin Aiguo; Zeng Hao

2004-01-01

Objective: To study the MR cholangiopancreatography (MRCP) characteristics of different pancreatic diseases, and to identify the diagnostic value of MRCP for pancreatic diseases. Methods: One hundred and eleven patients with suspected pancreatic diseases underwent MRCP examination. The MRCP sequences included thick-slice turbo spin echo (TSE) and thin-slice half-Fourier acquisition single shot turbo spin echo (HASTE) sequences. The pancreatic diseases included pancreatic carcinoma (n=46), chronic pancreatitis (n=39), peri-ampullar carcinoma (n=23), and choledocholith (n=3). Results: (1) The abnormal manifestation of pancreatic duct was observed in 37 cases of pancreatic carcinoma, 24 cases of chronic pancreatitis, and 12 cases of peri-ampullar carcinoma. Dilated pancreatic duct with smooth and regular caliber was observed in 33 cases of pancreatic carcinoma, 0 case of chronic pancreatitis, and 12 cases of peri-ampullar carcinoma, and statistical analysis showed significant difference (χ 2 =57.911, P 2 =60.343, P 2 =61.217, P 2 =34.654, P 2 =54.593, P<0.01). Conclusion: Different MRI characteristics were observed in various pancreatic diseases respectively. MRCP can show the subtle differences among the pancreatic diseases, and is very helpful in the diagnosis and differential diagnosis of pancreatic diseases

The role of MR cholangiopancreatography in acute abdominal pain (a case study)

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Obradovic, G.

2000-01-01

Rapid technological advances have resulted in improved Magnetic Resonance Imaging (MRI) of the abdomen. In particular, the development of single breath hold sequences have led to a resurgence in imaging of the binary tree and pancreatic duct. For this reason, Magnetic Resonance Cholangiopancreatography (MRCP) is recognised as a valuable tool which is safe, fast and noninvasive. This case study demonstrates that MRCP could identify the intrahepatic duct obstruction adequately, so that the appropriate course of management could be readily instigated. In addition, the excellent quality of MR imaging will lead to an increase in referrals for MRCP if the modality is available and there are no patient contra-indications. Copyright (1999) Australian Institute of Radiography

Utility of MRCP in clinical decision making of suspected choledocholithiasis: An institutional analysis and literature review.

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Badger, Wesley R; Borgert, Andrew J; Kallies, Kara J; Kothari, Shanu N

2017-08-01

The ideal treatment algorithm for suspected choledocholithiasis is not yet well defined. Imaging options include magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiopancreatography (ERCP), and intraoperative cholangiogram (IOC). MRCP is diagnostic, while the other two modalities can also be therapeutic. Each of these modalities for diagnosis and treatment carries its own set of risks, benefits, and institutional costs. We hypothesized that there would be a significant difference between the biochemical profiles and characteristics of patients who undergo ERCP vs. MRCP vs. operative intervention as the initial choice of treatment/imaging modality. We performed a retrospective review of the electronic medical records for all patients with a coded diagnosis of choledocholithiasis from 2011 to 2014. The initial diagnostic modality was assessed for each hospital encounter. The statistical characteristics of MRCP as compared to fluoroscopic imaging of the biliary tree (ERCP, IOC) were analyzed. Overall, 527 hospital encounters were identified. Initial intervention included ERCP in 63%, MRCP in 12%, and cholecystectomy in 25% of patients. Patients undergoing cholecystectomy first, compared to MRCP or ERCP, tended to have lower values for alkaline phosphatase (P utility in this patient population should be questioned. Further research is needed to better define the pretest characteristics which would predict which patients do not need further intervention after MRCP as well as defining the most cost-effective strategy. Copyright © 2016 Elsevier Inc. All rights reserved.

Magnetic Resonance Cholangiopancreatography (MRCP)

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... radio waves and a computer to evaluate the liver, gallbladder, bile ducts, pancreas and pancreatic duct for disease. It is ... of the hepatobiliary and pancreatic systems, including the liver, gallbladder, bile ducts, pancreas and pancreatic duct . Magnetic resonance imaging (MRI) ...

Does secretin stimulation add to magnetic resonance cholangiopancreatography in characterising pancreatic cystic lesions as side-branch intraductal papillary mucinous neoplasm?

International Nuclear Information System (INIS)

Purysko, Andrei S.; Gandhi, Namita S.; Veniero, Joseph C.; Walsh, R.M.; Obuchowski, Nancy A.

2014-01-01

To assess the value of secretin during magnetic resonance cholangiopancreatography (MRCP) in demonstrating communication between cystic lesions and the pancreatic duct to help determine the diagnosis of side-branch intraductal papillary mucinous neoplasm (SB-IPMN). This is an IRB-approved, HIPAA-compliant retrospective study of 29 SB-IPMN patients and 13 non-IPMN subjects (control) who underwent secretin-enhanced MRCP (s-MRCP). Two readers blinded to the final diagnosis reviewed three randomised image sets: (1) pre-secretin HASTE, (2) dynamic s-MRCP and (3) post-secretin HASTE. Logistic regression, generalised linear models and ROC analyses were used to compare pre- and post-secretin results. There was no significant difference in median scores for the pre-secretin [reader 1: 1; reader 2: 2 (range -2 to 2)] and post-secretin HASTE [reader 1: 1; reader 2: 1 (range -2 to 2)] in the SB-IPMN group (P = 0.14), while the scores were lower for s-MRCP [reader 1: 0.5 (range -2 to 2); reader 2: 0 (range -1 to 2); P = 0.016]. There was no significant difference in mean maximum diameter of SB-IPMN on pre- and post-secretin HASTE, and s-MRCP (P > 0.05). Secretin stimulation did not add to MRCP in characterising pancreatic cystic lesions as SB-IPMN. (orig.)

Sensitivity of endoscopic ultrasound, multidetector computed tomography, and magnetic resonance cholangiopancreatography in the diagnosis of pancreas divisum: a tertiary center experience.

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Kushnir, Vladimir M; Wani, Sachin B; Fowler, Kathryn; Menias, Christine; Varma, Rakesh; Narra, Vamsi; Hovis, Christine; Murad, Faris M; Mullady, Daniel K; Jonnalagadda, Sreenivasa S; Early, Dayna S; Edmundowicz, Steven A; Azar, Riad R

2013-04-01

There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: (1) evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP), and multidetector computed tomography (MDCT) for pancreas divisum; and (2) assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent endoscopic retrograde pancreatography and cross-sectional imaging. The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than the sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) (P pancreas divisum; IOA was moderate (κ = 0.43). Endoscopic ultrasound is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum.

3 T MR cholangiopancreatography appearances of biliary ascariasis

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Ding, Z.X., E-mail: hangzhoudzx73@126.co [Department of Radiology, Zhejiang Provincial People' s Hospital, Hangzhou (China); Yuan, J.H. [Department of Radiology, Zhejiang Provincial People' s Hospital, Hangzhou (China); Chong, V. [Department of Diagnostic Imaging, National University Health System, Yong Loo Lin School of Medicine, National University of Singapore (Singapore); Zhao, D.J. [Department of Hepatobiliary Surgery, Zhejiang Provincial People' s Hospital, Hangzhou (China); Chen, F.H.; Li, Y.M. [Department of Radiology, Zhejiang Provincial People' s Hospital, Hangzhou (China)

2011-03-15

Aim: To evaluate the 3 T MR cholangiopancreatography (MRCP) appearances of biliary ascariasis. Materials and methods: Nine patients with a MRCP diagnosis of biliary ascariasis were reviewed. All patients had endoscopic retrograde cholangiopancreatography (ERCP) or surgical confirmation of the disease. Results: On thin-slab MRCP imaging, Ascaris worms are clearly demarcated within the biliary tree. All the identified worms demonstrated a characteristic three-parallel-lines appearance. The middle high-signal intensity line is sandwiched between two low-signal intensity lines and they are in turn surrounded by high signal bile. On thick-slab MRCP the worms also show the three-line sign but with less clarity. However, thick-slab MRCP has the advantage of providing three-dimensional ERCP-like images of the pancreaticobiliary system. Conclusion: The 'three-line' sign appears to be a characteristic sign of biliary ascariasis on 3 T MRCP.

SENSITIVITY OF ENDOSCOPIC ULTRASOUND, MULTIDETECTOR COMPUTER TOMOGRAPHY AND MAGNETIC RESONANCE CHOLANGIOPANCREATOGRAPHY IN THE DIAGNOSIS OF PANCREAS DIVISUM: A TERTIARY CENTER EXPERIENCE

Science.gov (United States)

Kushnir, Vladimir M.; Wani, Sachin B.; Fowler, Kathryn; Menias, Christine; Varma, Rakesh; Narra, Vamsi; Hovis, Christine; Murad, Faris; Mullady, Daniel; Jonnalagadda, Sreenivasa S.; Early, Dayna S.; Edmundowicz, Steven A.; Azar, Riad R.

2014-01-01

OBJECTIVES There are limited data comparing imaging modalities in the diagnosis of pancreas divisum. We aimed to: 1. Evaluate the sensitivity of endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP) and multi-detector computed tomography (MDCT) for pancreas divisum. 2. Assess interobserver agreement (IOA) among expert radiologists for detecting pancreas divisum on MDCT and MRCP. METHODS For this retrospective cohort study, we identified 45 consecutive patients with pancreaticobiliary symptoms and pancreas divisum established by endoscopic retrograde pancreatography (ERP) who underwent EUS and cross-sectional imaging. The control group was composed of patients without pancreas divisum who underwent ERP and cross-sectional imaging. RESULTS The sensitivity of EUS for pancreas divisum was 86.7%, significantly higher than sensitivity reported in the medical records for MDCT (15.5%) or MRCP (60%) [ppancreas divisum; IOA was moderate (қ=0.43). CONCLUSIONS EUS is a sensitive test for diagnosing pancreas divisum and is superior to MDCT and MRCP. Review of MDCT studies by expert radiologists substantially raises its sensitivity for pancreas divisum. PMID:23211370

Normal pancreatic exocrine function does not exclude MRI/MRCP chronic pancreatitis findings.

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Alkaade, Samer; Cem Balci, Numan; Momtahen, Amir Javad; Burton, Frank

2008-09-01

Abnormal pancreatic function tests have been reported to precede the imaging findings of chronic pancreatitis. Magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) is increasingly accepted as the primary imaging modality for the detection of structural changes of early mild chronic pancreatitis. The aim of this study was to evaluate MRI/MRCP findings in patients with symptoms consistent with chronic pancreatitis who have normal Secretin Endoscopic Pancreatic Function test. A retrospective study of 32 patients referred for evaluation of chronic abdominal pain consistent with chronic pancreatitis and reported normal standard abdominal imaging (ultrasound, computed tomography, or MRI). All patients underwent Secretin Endoscopic Pancreatic Function testing and pancreatic MRI/MRCP at our institution. We reviewed the MRI/MRCP images in patients who had normal Secretin Endoscopic Pancreatic Function testing. MRI/MRCP images were assessed for pancreatic duct morphology, gland size, parenchymal signal and morphology, and arterial contrast enhancement. Of the 32 patients, 23 had normal Secretin Endoscopic Pancreatic Function testing, and 8 of them had mild to marked spectrum of abnormal MRI/MRCP findings that were predominantly focal. Frequencies of the findings were as follows: pancreatic duct stricture (n=3), pancreatic duct dilatation (n=3), side branch ectasia (n=4), atrophy (n=5), decreased arterial enhancement (n=5), decreased parenchymal signal (n=1), and cavity formation (n=1). The remaining15 patients had normal pancreatic structure on MRI/MRCP. Normal pancreatic function testing cannot exclude abnormal MRI/MRCP especially focal findings of chronic pancreatitis. Further studies needed to verify significance of these findings and establish MRI/MRCP imaging criteria for the diagnosis of chronic pancreatitis.

Noninvasive study of anatomic variations of the bile and pancreatic duct using magnetic resonance cholangiopancreatography; Estudio no invasivo de variantes anatomicas de la via biliar y pancreatica mediante colangiopancreatografia por resonancia magnetica (CPRM)

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Fernandez, E.; Falco, J.; Campo, R.; Martin, J.; Brullet, E. [SDI-UDIAT Corporacio Sanitaria Parc Tauli. Sabadell (Spain); Espinos, J. [Hospital Mutua de Tarrasa (Spain)

1999-07-01

To identify anatomic variations of the bile duct and pancreatic duct and papillary anomalies by means of magnetic resonance cholangiopancreatography (MRCP) and determine their correlation with endoscopic retrograde cholangiopancreatography (ERCP) findings. Eighty-five patients were selected by means of a prospective study comparing MRCP and ERCP. Coronal and axial HASTE images and coronal and oblique coronal RARE images were acquired in all the patients. Four of the studies (6%) were excluded because of poor technical quality. Anatomic variations were observed in 26 cases (30.5%), including trifurcation (n=7; 27%), right hepatic duct draining into left hepatic duct (n=2, 7.7%), right hepatic duct draining into common bile duct (n=4; 15.4%), extrahepatic confluence (n=2; 7.7%), medial cystic duct (n=2; 7.7%), parallel cystic duct (n=3; 11.5%), juxtapapillary duodenal diverticulum (n=3; 11.5%) and pancreas divisum (n=3; 11.5%). A good correlation was observed between the MRCP and ERCP findings. The introduction of MRCP into the noninvasive study of biliary disease may be useful in the detection of anatomic variations relevant to laparoscopic surgery and other endoscopic and interventional techniques. (Author) 11 refs.

Assessment of MRI and MRCP in diagnosis of biliary cystadenoma and cystadenocarcinoma

International Nuclear Information System (INIS)

Lewin, Maite; Arrive, Lionel; Tubiana, Jean-Michel; Mourra, Najat; Flejou, Jean-Francois; Honigman, Isabelle; Parc, Rolland

2006-01-01

Magnetic resonance imaging (MRI) and magnetic resonance cholangio-pancreatography (MRCP) features were analyzed in the diagnosis of seven surgically resected hepatobiliary cystic tumors with reference to histopathological data. Homogeneity, size, location, signal intensity, presence or absence of septa and/or nodules and MRCP features of the lesions were studied. Histological evidence demonstrated six biliary cystadenoma (BCA) including four pseudo-ovarian stroma (POS) and one biliary cystadenocarcinoma (BCAC). Cystic lesions (3-15 cm in diameter) were homogeneous in the six BCA, heterogeneous in the one BCAC, and were located in the left and right liver, respectively. On T2-weighted images all lesions were hyperintense. On T1-weighted images hypointensity was found in three BCA (all serous fluid, including one POS), isointensity was found in the three others (two mucinous and one hemorrhagic fluid, including three POS) and in the one BCAC (containing mucinous fluid). Septas were present in all cases and nodules only in the one BCAC. On MRCP a hyperintense cystic lesion was found in all cases and a bile ducts dilatation in two BCA and the one BCAC. Gadolinium-enhanced MRI in combination with MRCP is a valuable tool for the diagnosis of BCA or BCAC. However, no specific information is gained for POS detection. (orig.)

The exploratory development of A self-made oral Gd-DTPA solution for low field MRCP in children

International Nuclear Information System (INIS)

Sheng Mao; Zhou Min; Gu Zhicheng; Wu Jizhi; Guo Wanliang; Ni Yongbiao; Fang Lin

2010-01-01

Objective: To evaluate the value of ingestion self-made Gd-DTPA solutin for low field magnetic resonance cholangiopancreatography (MRCP) (0.35T) in children. Methods: Phantom experiments were performed to select the optimal concentration of Gd-DTPA to be used as an oral negative contrast agent in low field MRCP. Twenty children suspected of celiac disease were performed with MRCP before and after ingestion Gd-DTPA solution. Signal intensity measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. Results: The selected Gd-DTPA concentration was 1.992 mmol/L. Ingestion of 80 ml solution eliminated or suppressed efficiently the gastroduodenal signal intensity, improving the MRCP image quality scores (P<0.01) significantly in children. Conclusion: 1.992 mmol/L self-made Gd-DTPA solutin can suppress or eliminate water signals from gastrointestinal tract and improve the quality of low field MRCP image in children. (authors)

MRCP and 3D LAVA imaging of extrahepatic cholangiocarcinoma at 3 T MRI

Energy Technology Data Exchange (ETDEWEB)

Li, N.; Liu, C.; Bi, W.; Lin, X.; Jiao, H. [Shandong Medical Imaging Research Institute, Shandong University, Jinan (China); Zhao, P., E-mail: Gavinsdu@163.com [Department of Radiology, Shandong Provincial Hospital, Shandong University, Jinan (China)

2012-06-15

Extrahepatic cholangiocarcinoma (CCA) is a primary bile duct malignant tumour with poor prognosis. Familiarity with their varied imaging characteristics can be helpful in developing a correct diagnosis and in optimal treatment planning, and thus contribute to a better prognosis. The purpose of this article is to illustrate the typical appearances of extrahepatic CCA on magnetic resonance cholangiopancreatography (MRCP) and three-dimensional (3D) LAVA (liver acquisition with volume acceleration) sequences at 3 T magnetic resonance imaging (MRI), and to discuss the superiority of the two techniques in the diagnosis of CCA.

An incidental case of biliary fascioliasis with subtle clinical findings: US and MRCP findings

International Nuclear Information System (INIS)

Önder, Hakan; Ekici, Faysal; Adin, Emin; Kuday, Suzan; Gümüş, Hatice; Bilici, Aslan

2013-01-01

Fascioliasis is a disease caused by the trematode Fasciola hepatica. Cholangitis is a common clinical manifestation. Although fascioliasis may show various radiological and clinical features, cases without biliary dilatation are rare. We present unique ultrasound (US) and magnetic resonance cholangiopancreatography (MRCP) findings of a biliary fascioliasis case which doesn’t have biliary obstruction or cholestasis. Radiologically, curvilinear parasites compatible with juvenile and mature Fasciola hepatica within the gallbladder and common bile duct were found. The parasites appear as bright echogenic structures with no acoustic shadow on US and hypo-intense curvilinear lesions on T2 weighted MRCP images. Imaging studies may significantly contribute to the diagnosis of patients with subtle clinical and laboratory findings, particularly in endemic regions

Contribution of abdoscan using MR cholangio-pancreatography and MR urography

International Nuclear Information System (INIS)

Lecesne, R.; Drouillard, J.; Cisse, R.; Schiratti, M.

1998-01-01

MR cholangio-pancreatography (MRCP) and MR Urography (MRU) are promising recent imaging modalities. Oral magnetic particles (Abdoscan, Nycomed SA, Oslo, Norway) is an negative contrast agent eliminating signal intensity of the gastro-intestinal tract thus improvising image quality at MRCP and MRU. (author)

MR cholangiopancreatography in children: feasibility, safety, and initial experience

International Nuclear Information System (INIS)

Delaney, Lisa; Karmazyn, Boaz; Akisik, M.F.; Jennings, S.G.; Applegate, Kimberly E.

2008-01-01

The indications for MR cholangiopancreatography (MRCP) in children, and its safety and findings, might differ from those in adults and are not well described. To investigate the safety, feasibility, and accuracy of MRCP in children. We reviewed all prospective MRCP reports, noting the indication, the use of secretin, endoscopic retrograde cholangiopancreatography (ERCP) findings, and patient outcomes. Two readers reviewed each MRCP study by consensus to rate duct visualization and compare pancreatic duct sizes before and after secretin administration (paired t-test). The likelihood of a normal versus an abnormal MRCP study was compared by gender, pancreatitis as the primary indication, secretin use, and whether ERCP was performed (Fisher's exact test), as well as age (t-test). A total of 85 MRCP studies were performed in children (mean age 10.3 years), most commonly for evaluation of pancreatitis (n=47, 55%); 41 (48%) used secretin and 39 (46%) used a negative oral contrast agent. Of the 85 studies, 72 (85%) had excellent image quality and 43 were normal. ERCP was performed after 16 of the 85 MRCP studies (19%); the diagnoses were concordant with those of MRCP in 13 (81%). There were 42 abnormal MRCP studies, and these were more likely to be in girls (P=0.03) and in children who had undergone ERCP (P<0.01). Secretin and the negative oral contrast agent were well-tolerated. Secretin improved duct visualization (P<0.001). MRCP safely and accurately depicted pancreaticobiliary anatomy in children. The use of secretin improved visualization of the pancreatic duct. (orig.)

Clinical evaluation of further-developed MRCP sequences in comparison with standard MRCP sequences

International Nuclear Information System (INIS)

Hundt, W.; Scheidler, J.; Reiser, M.; Petsch, R.

2002-01-01

The purpose of this study was the comparison of technically improved single-shot magnetic resonance cholangiopancreatography (MRCP) sequences with standard single-shot rapid acquisition with relaxation enhancement (RARE) and half-Fourier acquired single-shot turbo spin-echo (HASTE) sequences in evaluating the normal and abnormal biliary duct system. The bile duct system of 45 patients was prospectively investigated on a 1.5-T MRI system. The investigation was performed with RARE and HASTE MR cholangiography sequences with standard and high spatial resolutions, and with a delayed-echo half-Fourier RARE (HASTE) sequence. Findings of the improved MRCP sequences were compared with the standard MRCP sequences. The level of confidence in assessing the diagnosis was divided into five groups. The Wilcoxon signed-rank test at a level of p<0.05 was applied. In 15 patients no pathology was found. The MRCP showed stenoses of the bile duct system in 10 patients and choledocholithiasis and cholecystolithiasis in 16 patients. In 12 patients a dilatation of the bile duct system was found. Comparison of the low- and high spatial resolution sequences and the short and long TE times of the half-Fourier RARE (HASTE) sequence revealed no statistically significant differences regarding accuracy of the examination. The diagnostic confidence level in assessing normal or pathological findings for the high-resolution RARE and half-Fourier RARE (HASTE) was significantly better than for the standard sequences. For the delayed-echo half-Fourier RARE (HASTE) sequence no statistically significant difference was seen. The high-resolution RARE and half-Fourier RARE (HASTE) sequences had a higher confidence level, but there was no significant difference in diagnosis in terms of detection and assessment of pathological changes in the biliary duct system compared with standard sequences. (orig.)

MR cholangiopancreatography: prospective comparison of a breath-hold 2D projection technique with diagnostic ERCP

International Nuclear Information System (INIS)

Lomas, D.J.; Bearcroft, P.W.P.; Gimson, A.E.

1999-01-01

The aim of this study was to compare prospectively a breath-hold projection magnetic resonance cholangiopancreatography (MRCP) technique with diagnostic endoscopic retrograde cholangiopancreatography (ERCP). Seventy-six patients with suspected strictures or choledocholithiasis were referred for MRCP and subsequent ERCP examination, which were performed within 4 h of each other. The MRCP technique was performed using fat-suppressed rapid acquisition with relaxation enhancement (RARE) projection images obtained in standardised planes with additional targeted projections as required by the supervising radiologist. Two radiologists (in consensus) assessed the MRCP results prospectively and independently for the presence of bile duct calculi, strictures, non-specific biliary dilatation and pancreatic duct dilatation, and recorded a single primary diagnosis. The ERCP was assessed prospectively and independently by a single endoscopist and used as a gold standard for comparison with MRCP. Diagnostic agreement was assessed by the Kappa statistic. The MRCP technique failed in two patients and ERCP in five. In the remaining 69 referrals ERCP demonstrated normal findings in 23 cases, strictures in 19 cases, choledocholithiasis in 9 cases, non-specific biliary dilatation in 14 cases and chronic pancreatitis in 4 cases. The MRCP technique correctly demonstrated 22 of 23 normal cases, 19 strictures with one false positive (sensitivity 100 %, specificity 98 %), all 9 cases of choledocholithiasis with two false positives (sensitivity 100 %, specificity 97 %), 12 of 14 cases of non-specific biliary dilatation and only 1 of 4 cases of chronic pancreatitis. There was overall good agreement for diagnosis based on a kappa value of 0.88. Breath-hold projection MRCP can provide non-invasively comparable diagnostic information to diagnostic ERCP for suspected choledocholithiasis and biliary strictures and may allow more selective use of therapeutic ERCP. (orig.)

Hepatic involvement of Langerhans cell histiocytosis in children - imaging findings of computed tomography, magnetic resonance imaging and magnetic resonance cholangiopancreatography

International Nuclear Information System (INIS)

Shi, Yingyan; Qiao, Zhongwei; Gong, Ying; Yang, Haowei; Li, Guoping; Pa, Mier; Xia, Chunmei

2014-01-01

Langerhans cell histiocytosis is a rare disease that occurs mainly in children, and hepatic involvement is generally a poor prognostic factor. To describe CT and MRI findings of hepatic involvement of Langerhans cell histiocytosis in children, especially the abnormal bile duct manifestation on magnetic resonance cholangiopancreatography (MRCP). Thirteen children (seven boys, six girls; mean age 28.9 months) were diagnosed with disseminated Langerhans cell histiocytosis. They underwent CT (n = 5) or MRI (n = 4), or CT and MRI examinations (n = 4) to evaluate the liver involvement. Periportal abnormalities presented as band-like or nodular lesions on CT and MRI in all 13 children. The hepatic parenchymal lesions were found in the peripheral regions of the liver in seven children, including multiple nodules on MRI (n = 6), and cystic-like lesions on CT and MRI (n = 3). In 11 of the 13 children the dilatations of the bile ducts were observed on CT and MRI. Eight of the 13 children underwent MR cholangiopancreatography, which demonstrated stenoses or segmental stenoses with slight dilatation of the central bile ducts, including the common hepatic duct and its first-order branches. The peripheral bile ducts in these children showed segmental dilatations and stenoses. Stenosis of the central bile ducts revealed by MR cholangiopancreatography was the most significant finding of liver involvement in Langerhans cell histiocytosis in children. (orig.)

Hepatic involvement of Langerhans cell histiocytosis in children - imaging findings of computed tomography, magnetic resonance imaging and magnetic resonance cholangiopancreatography

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Shi, Yingyan; Qiao, Zhongwei; Gong, Ying; Yang, Haowei; Li, Guoping; Pa, Mier [Children' s Hospital of Fudan University, Department of Radiology, Shanghai (China); Xia, Chunmei [Shanghai Medical College of Fudan University, Physiology and Pathophysiology Department, Shanghai (China)

2014-06-15

Langerhans cell histiocytosis is a rare disease that occurs mainly in children, and hepatic involvement is generally a poor prognostic factor. To describe CT and MRI findings of hepatic involvement of Langerhans cell histiocytosis in children, especially the abnormal bile duct manifestation on magnetic resonance cholangiopancreatography (MRCP). Thirteen children (seven boys, six girls; mean age 28.9 months) were diagnosed with disseminated Langerhans cell histiocytosis. They underwent CT (n = 5) or MRI (n = 4), or CT and MRI examinations (n = 4) to evaluate the liver involvement. Periportal abnormalities presented as band-like or nodular lesions on CT and MRI in all 13 children. The hepatic parenchymal lesions were found in the peripheral regions of the liver in seven children, including multiple nodules on MRI (n = 6), and cystic-like lesions on CT and MRI (n = 3). In 11 of the 13 children the dilatations of the bile ducts were observed on CT and MRI. Eight of the 13 children underwent MR cholangiopancreatography, which demonstrated stenoses or segmental stenoses with slight dilatation of the central bile ducts, including the common hepatic duct and its first-order branches. The peripheral bile ducts in these children showed segmental dilatations and stenoses. Stenosis of the central bile ducts revealed by MR cholangiopancreatography was the most significant finding of liver involvement in Langerhans cell histiocytosis in children. (orig.)

Magnetic Resonance Cholangiopancreatography: Image Quality, Ductal Morphology, and Value of Additional T2- and T1-weighted Sequences for the Assessment of Suspected Pancreatic Cancer

International Nuclear Information System (INIS)

Lopez Haenninen, E.; Ricke, H.; Amthauer, H.; Roettgen, R.; Boehmig, M.; Langrehr, J.; Pech, M.; Denecke, T.; Rosewicz, S.; Felix, R.

2005-01-01

Purpose: To assess image quality and duct morphology on magnetic resonance cholangiopancreatography (MRCP) and also the value of additional T2- and T1-weighted sequences for differentiation of benignity and malignancy in patients with suspected pancreatic tumors. Material and Methods: One-hundred-and-fourteen patients received MRCP and unenhanced and contrast material-enhanced MR imaging. MR results were analyzed independently by two blinded readers, and subsequently correlated with the results from surgery, biopsy, and follow-up. Assessment included the evaluation of image quality, duct visualization and morphology, and the differentiation of pancreatic lesion status (benign versus malignant).Results: Overall, 49 patients had benign final diagnoses, while 65 had a malignant diagnosis. Image quality of single-shot thick-slab MRCP was rated significantly better than the MIP images of multisection MRCP. With MRCP alone, the two readers' accuracy in the assessment of pancreatic lesion status was 72% (95% CI, 64% to 83%) and 69% (95% CI, 56% to 77%), respectively; with the addition of T2- and T1-weighted images the accuracy significantly improved to 89% (95% CI, 82% to 95%) and 84% (95% CI, 77% to 92%) for readers 1 and 2, respectively. Conclusion: Single-shot thick-slab MRCP and multisection MRCP provide complementary results; however, single-shot MRCP had superior image quality. Moreover, assessment of ductal morphology with MRCP alone facilitated the diagnosis of different pathologic conditions of the pancreatobiliary system in the majority of patients. However, with the addition of T2- and T1-weighted sequences the overall diagnostic accuracy was significantly improved and thus we consider that a comprehensive MR approach should comprise both MRCP techniques and parenchymal sequences

Magnetic resonance cholangiopancreaticography as a diagnostic tool for common bile duct stones - A comparison with ERCP and clinical follow-up

NARCIS (Netherlands)

Kats, J; Kraai, M; Dijkstra, AJ; Koster, K; ter Borg, F; Hazenberg, HJA; Schattenkerk, ME; des Plantes, BGZ; Eddes, EH

2003-01-01

Background/Aims: The diagnostic potential of magnetic resonance cholangiopancreaticography (MRCP) has improved as a result of evolving technique. MRCP has the advantage of negligible morbidity and mortality in contrast to endoscopic retrograde cholangiopancreatography (ERCP). This study was

Non-invasive quantification of pancreatic exocrine function using secretin-stimulated MRCP

International Nuclear Information System (INIS)

Punwani, S.; Gillams, A.R.; Lees, W.R.

2003-01-01

Our objective was to quantify water volume using magnetic resonance cholangiopancreatography (MRCP) sequences and apply this to secretin-stimulated studies with the aim of quantifying pancreatic exocrine function. A commercially available single-shot MRCP sequence was used in conjunction with a body phased-array coil and a 1.5-T MR system. Signal intensity was measured in samples of water, pancreatic, duodenal juice, and secretin-stimulated pancreatic juice. A water phantom was made and MR calculated volumes compared with known water volumes within the phantom. Changes in small intestinal volume in response to secretin were measured in a group of 11 patients with no evidence of pancreatic disease. Changes in water volume were plotted over time. The pancreatic duct diameter before and after secretin was noted and filling defects were sought. All patients also underwent an axial breath-hold T1-weighted gradient-echo sequence and the pancreatic parenchyma was evaluated for size and signal intensity. There was no difference in the signal intensity of the different juice samples. There was excellent correlation between known and calculated MRCP volumes (χ 2 =0.99). All patients demonstrated normal duct morphology on MRCP and normal pancreatic parenchyma on T1-weighted imaging. The mean flow rate in the patient population was 8.1±2.5 ml/s over a median of 7 min (range 5-9 min). The MRCP sequence can be used to measure water volume. Sequential MRCP measurements following secretin permitted calculation of volume change and flow rate. This should prove useful as an indicator of pancreatic exocrine function. (orig.)

Noninvasive investigation of exocrine pancreatic function: Feasibility of cine dynamic MRCP with a spatially selective inversion-recovery pulse.

Science.gov (United States)

Yasokawa, Kazuya; Ito, Katsuyoshi; Tamada, Tsutomu; Yamamoto, Akira; Hayashida, Minoru; Tanimoto, Daigo; Higaki, Atsushi; Noda, Yasufumi; Kido, Ayumu

2015-11-01

To investigate the feasibility of noncontrast-enhanced cine dynamic magnetic resonance cholangiopancreatography (MRCP) with a spatially selective inversion-recovery (IR) pulse for evaluating exocrine pancreatic function in comparison with the N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA) test as a pancreatic exocrine function test. Twenty subjects with or without chronic pancreatitis were included. MRCP with a spatially selective IR pulse was repeated every 15 seconds for 5 minutes to acquire a total of 20 images (cine-dynamic MRCP). The median and mean frequency of the observation (the number of times) and the moving distance (mean secretion grading scores) of pancreatic juice inflow on cine-dynamic MRCP were compared with a BT-PABA test. The urinary PABA excretion rate (%) had significant positive correlations with both the mean secretion grade (r = 0.66, P = 0.002) and frequency of secretory inflow (r = 0.62, P = 0.004) in cine dynamic MRCP. Both the mean frequency of observations of pancreatic secretory inflow (1.4 ± 1.6 times vs. 14.3 ± 4.2 times, P Cine dynamic MRCP with a spatially selective IR pulse may have potential for estimating the pancreatic exocrine function noninvasively as a substitute for the BT-PABA test. © 2015 Wiley Periodicals, Inc.

Imaging of the normal and abnormal pancreaticobiliary system with single-shot MR cholangiopancreatography: a pictorial review

International Nuclear Information System (INIS)

Little, A. F.; Smith, P.J.; Lee, W.K.; Hennessy, O.F.; Lourensz, M.E.; Desmond, P.V.; Banting, S.W.

1999-01-01

Magnetic resonance cholangiopancreatography (MRCP) is a rapidly evolving non-invasive imaging modality that produces images of the pancreatic duct and binary tree without the need for intravenous or oral contrast. The images are equivalent to those from endoscopic retrograde cholangiopancreatography (ERCP), but the non-invasive acquisition avoids the morbidity and mortality associated with diagnostic ERCP. Magnetic resonance cholangiopancreatography is indicated in patients who require only a diagnostic ERCP, who fail an ERCP or who are unable to undergo ERCP due to altered post-surgical anatomy. Other evolving indications include triaging of patients with obstructive jaundice into percutaneous or endoscopic management drainage pathways depending on the site, length and nature of the duct obstruction, thereby potentially decreasing the number of failed or unsuccessful ERCP. Preoperative identification of anomalous binary anatomy and choledocholithiasis prior to laparoscopic cholecystectomy promise to modify the pre-operative and operative management of the patient in order to minimize the risk of duct injury and unnecessary intra-operative dissection and cholangiography. The advantages of the technique include its non-invasiveness, the absence of contrast administration, its relative operator independence and the ability to evaluate both sides of an obstructed duct, thereby accurately evaluating stricture morphology and length. The disadvantages of MRCP compared to ERCP include its lack of an immediate therapeutic solution to duct obstruction, procedural cost, unit availability and the inability to evaluate patients with pacemakers or ferromagnetic implants. Copyright (1999) Blackwell Science Pty Ltd

Role of diffusion-weighted magnetic resonance imaging in the diagnosis of extrahepatic cholangiocarcinoma

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

AIM: To determine the clinical value of diffusion-weight- ed imaging (DWI) for the diagnosis of extrahepatic cholangiocarcinoma (EHCC) by comparing the diagnostic sensitivity of DWI and magnetic resonance cholan-giopancreatography (MRCP). METHODS: Magnetic resonance imaging examination was performed in 56 patients with suspected EHCC. T1- weighted imaging, T2-weighted imaging, MRCP and DWI sequence, DWI using single-shot spin-echo echoplanar imaging sequence with different b values (100, 300, 500, 800 and 1...

MR cholangiopancreatography diagnosis for cholangitis caused by clonorchis sinensis

International Nuclear Information System (INIS)

Cui Bing; Hu Qiugen; Wang Yan

2003-01-01

Objective: To evaluate the MR cholangiopancreatography (MRCP) diagnosis for cholangitis caused by clonorchis sinensis. Methods: Fifty-four cases with cholangitis caused by clonorchis sinensis were examined by MRCP (3D FASE-Heavy T 2 WI sequence). The results of MRCP were compared with that of ERCP, laparoscopy, and pathology. Results: The diagnostic accuracy for the cause of the disease was 88.9%. Main findings on MRCP included slight dilation of the intra-hepatic biliary duct (n=46), small cystiform dilation of peripheral biliary ending (n=43), extra-hepatic biliary dilations (n=15) and strictures (n=19), and low signal intensity filling defect in the common bile duct and gallbladder (n=6). Conclusion: MRCP of biliary tree images can be obtained with 3D FASE Heavy T 2 WI sequence in considerable details. The characteristic of the cholangitis caused by clonorchis sinensis on MRCP was the slight dilation or stricture of extensive intra-hepatic biliary duct, combined with small cystiform dilation of peripheral biliary ending. MRCP was an ideal technique in diagnosing the disease

Diagnosis of mild chronic pancreatitis (Cambridge classification): comparative study using secretin injection-magnetic resonance cholangiopancreatography and endoscopic retrograde pancreatography.

Science.gov (United States)

Sai, Jin-Kan; Suyama, Masafumi; Kubokawa, Yoshihiro; Watanabe, Sumio

2008-02-28

To investigate the usefulness of secretin injection-MRCP for the diagnosis of mild chronic pancreatitis. Sixteen patients having mild chronic pancreatitis according to the Cambridge classification and 12 control subjects with no abnormal findings on the pancreatogram were examined for the diagnostic accuracy of secretin injection-MRCP regarding abnormal branch pancreatic ducts associated with mild chronic pancreatitis (Cambridge Classification), using endoscopic retrograde cholangiopancreatography (ERCP) for comparison. The sensitivity and specificity for abnormal branch pancreatic ducts determined by two reviewers were respectively 55%-63% and 75%-83% in the head, 57%-64% and 82%-83% in the body, and 44%-44% and 72%-76% in the tail of the pancreas. The sensitivity and specificity for mild chronic pancreatitis were 56%-63% and 92%-92%, respectively. Interobserver agreement (kappa statistics) concerning the diagnosis of an abnormal branch pancreatic duct and of mild chronic pancreatitis was good to excellent. Secretin injection-MRCP might be useful for the diagnosis of mild chronic pancreatitis.

Evaluation fo MR cholangio-pancreatography in the diagnosis of pancreaticobiliary diseases. In comparison with ERCP

International Nuclear Information System (INIS)

Saito, Masayuki; Watahiki, Hajime; Yamamoto, Hideaki

1995-01-01

The clinical usefulness of MR cholangio-pancreatography (MRCP) by fast spin echo method was compared with that of endoscopic retrograde cholangio pancreatography (ERCP). In MRCP, favorable images of bile and pancreatic ducts were obtained in 66.7% (78/117) and bile duct images in 16.2% (19/117), showing the overall efficacy rate of 92.9% (97/117). Seventy-seven of these images were compared with simultaneously obtained favorable ERCP images. The excellent and favorable rate of MRCP reached 84.5% (65/77), showing clinical usefulness of MRCP. Obscure images were considered due to insufficient breath-hold time. (S.Y.)

Usefulness of magnetic resonance cholangiography in the diagnosis of biliary tract lesions in patients with suspected complication following cholecystectomy

International Nuclear Information System (INIS)

Cecin, Alexandre de Oliveira; Goldman, Suzan Menasce; Caetano, Simone; Rosas, George de Queiroz; Coelho, Rafael Darahem de Souza; Lobo, Edson Jose; Abdalla, Nitamar; Szejnfeld, Jacob

2005-01-01

Objective: to determine the usefulness of magnetic resonance cholangiopancreatography (MRCP) in the diagnoses of bile duct injuries following cholecystectomy. Material and method: MRCP was retrospectively evaluated in 40 patients with suspected bile duct injury after laparoscopic or conventional cholecystectomy. Eight of these patients had been submitted to biliary reconstruction. All patients were symptomatic (jaundice, fever and chills, weight loss and abdominal pain). The scans were independently reviewed by two radiologists. The results were confirmed by surgery, percutaneous drainage, endoscopic retrograde cholangiopancreatography and clinical follow-up. The level and severity of bile duct injury were rated according to the Bismuth classification. Results: in a total of 40 symptomatic patients, 10 (25%) had normal findings on MRCP; Postoperative complications were seen in 29 (72.5%) patients, seven of them with more than one finding. Pancreatic head neoplasia was diagnoses in one patient. The most frequent finding was sclerosing (41.4%) followed by biliary duct stenosis (34.5%), residual or recurrent biliary stones (31.0%) and fluid collections (17.2%). The images obtained by MRCP were considered of good quality. Conclusion: MRCP is an effective method for the evaluation of patients with suspected postcholecystectomy biliary tract complications. (author)

Differential diagnosis of benign and malignant intraductal papillary mucinous tumors of the pancreas: MR cholangiopancreatography and MR angiography

International Nuclear Information System (INIS)

Choi, Byung Se; Kim, Tae Kyoung; Kim, Ah Young; Kim, Kyoung Won; Park, Sung Won; Kim, Pyo Nyun; Ha, Kyun Kwon; Lee, Moon Gyu; Kim, Song Cheol

2003-01-01

To compare the usefulness of magnetic resonance cholangiopancreatography (MRCP) and MR angiography (MRA) in differentiating malignant from benign intraductal papillary mucinous tumors of the pancreas (IPMTs), and to determine the findings which suggest malignancy. During a 6-year period, 46 patients with IPMT underwent MRCP. Morphologically, tumor type was classified as main duct, branch duct, or combined. The diameter of the main pancreatic duct (MPD), the extent of the dilated MPD, and the location and size of the cystic lesion, septum, and communicating channel were assessed. For all types of IPMTs, enhanced mural nodules and portal vein narrowing were evaluated at MRA. Combined-type IPMTs were more frequently malignant (78%) than benign (42%) (p<0.05). Compared with benign lesions, malignant lesions were larger, and the caliber of the communicating channel was also larger (p < 0.05). Their dilated MPD was more extensive and of greater diameter (p<0.05), and the presence of mural nodules was more frequent (p<0.001). Combined MRCP and MRA might be useful for the differential diagnosis of malignant and benign IPMTs of the pancreas

Detection of common bile duct stones: comparison between endoscopic ultrasonography, magnetic resonance cholangiography, and helical-computed-tomographic cholangiography

International Nuclear Information System (INIS)

Kondo, Shintaro; Isayama, Hiroyuki; Akahane, Masaaki; Toda, Nobuo; Sasahira, Naoki; Nakai, Yosuke; Yamamoto, Natsuyo; Hirano, Kenji; Komatsu, Yutaka; Tada, Minoru; Yoshida, Haruhiko; Kawabe, Takao; Ohtomo, Kuni; Omata, Masao

2005-01-01

Objectives: New modalities, namely, endoscopic ultrasonography (EUS), magnetic resonance cholangiopancreatography (MRCP), and helical computed-tomographic cholangiography (HCT-C), have been introduced recently for the detection of common bile duct (CBD) stones and shown improved detectability compared to conventional ultrasound or computed tomography. We conducted this study to compare the diagnostic ability of EUS, MRCP, and HCT-C in patients with suspected choledocholithiasis. Methods: Twenty-eight patients clinically suspected of having CBD stones were enrolled, excluding those with cholangitis or a definite history of choledocholithiasis. Each patient underwent EUS, MRCP, and HCT-C prior to endoscopic retrograde cholangio-pancreatography (ERCP), the result of which served as the diagnostic gold standard. Results: CBD stones were detected in 24 (86%) of 28 patients by ERCP/IDUS. The sensitivity of EUS, MRCP, and HCT-C was 100%, 88%, and 88%, respectively. False negative cases for MRCP and HCT-C had a CBD stone smaller than 5 mm in diameter. No serious complications occurred while one patient complained of itching in the eyelids after the infusion of contrast agent on HCT-C. Conclusions: When examination can be scheduled, MRCP or HCT-C will be the first choice because they were less invasive than EUS. MRCP and HCT-C had similar detectability but the former may be preferable considering the possibility of allergic reaction in the latter. When MRCP is negative, EUS is recommended to check for small CBD stones

Biliary anatomy in potential right hepatic lobe living donor liver transplantation (LDLT): The utility of CT cholangiography in the setting of inconclusive MRCP

International Nuclear Information System (INIS)

McSweeney, Sean E.; Kim, Tae Kyoung; Jang, Hyun-Jung; Khalili, Korosh

2012-01-01

Objective: To determine the utility of CT cholangiography (CT-Ch) in preoperative evaluation of the biliary anatomy of living-donor liver transplantation (LDLT) donors when magnetic resonance cholangiopancreatography (MRCP) is inconclusive. Materials and methods: Over a 2-year period, 22 potential living liver donors underwent contrast-enhanced CT-Ch for preoperative evaluating biliary anatomy due to inconclusive results on MRCP and subsequently donated their right hepatic lobe. Nineteen of them underwent intraoperative cholangiography and were included in this study. Two radiologists retrospectively reviewed both MRCP and CT-Ch with 1-month interval and documented the types of bile duct branching patterns and visualization score of intrahepatic bile ducts (4-point scale). Results: There were no complications associated with CT-Ch examinations. CT-Ch was concordant with the reference standard in 18/19 (95%) including 7/8 typical branching type and 11/11 anomalous branching types. MRCP was concordant with the reference standard in 14/19 (74%) including 4/8 typical branching types and 10/11 anomalous branching types. The discordant case by CT-Ch was the identification of a tiny accessory right intrahepatic duct joining the common bile duct which was not visualized on intraoperative cholangiography. CT-Ch showed higher visualization score (mean, 3.9) than MRCP (mean, 2.6) (P < .001). Conclusion: CT-Ch can be effectively used for the depiction of the branching pattern of the bile duct at the hepatic hilum when MRCP is inconclusive.

Magnetic Resonance Cholangiopancreatographv: A Meta-Analysis of Test Performance in Suspected Biliary Disease

International Nuclear Information System (INIS)

Romagnuolo J; Bardou M; Rahme, E and others

2004-01-01

Magnetic resonance cholangiopancreatography (MRCP) is one of many newer noninvasive tests that can image the biliary tree. To precisely estimate the overall sensitivity and specificity of MRCP in suspected biliary obstruction and to evaluate clinically important subgroups. MEDLINE search (January 1987 to March 2003) for studies in English or French, bibliographies, and subject matter experts. Studies were included if they allowed construction of 2x2 contingency tables of MRCP compared with a reasonable gold standard for at least 1 of the following: the presence, level, or cause of biliary obstruction. Two independent observers graded study quality, which included consecutive enrollment, blinding, use of a single (versus composite) gold standard, and nonselective use of the gold standard. Logistic regression was used to examine the influence of publication year, quality score, proportion of patients having a direct gold standard, and clinical context on diagnostic performance. Of 498 studies identified, 67 were included (4711 patients). Mixed-effect models were used to estimate the sensitivity and specificity, and quantitative receiver-operating characteristic analysis was performed. Magnetic resonance cholangiopancreatography had a high overall pooled sensitivity (95% (+/-1.96 SD: spread of SD, 75% to 99%) and specificity (97% (spread of SD, 86% to 99 %)) The procedure was less sensitive for stones (92%; odds ratio, 0.51 (CI, 0.35 to 0.75) and malignant conditions (88%; odds ratio, 0.28 (CI, 0.18 to 0.44f) than for the presence of obstruction, In addition, diagnostic performance was higher in studies that were larger, did not use consecutive enrollment, and did not use gold standard assessment for some patients. Magnetic resonance cholangiopancreatography is a noninvasive imaging test with excellent overall sensitivity and specificity for demonstrating the level and presence of biliary obstruction; however, it seems less sensitive for detecting stones or

The Impact of Gd-Eob-Dtpa-Enhanced MR Cholangiography in Biliary Diseases: Comparison with T2-Weighted MR Cholangiopancreatography

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Evrim Özmen

2016-06-01

Full Text Available Background: Contrast enhanced magnetic resonance cholangiography is a novel technique and promising method in demonstrating biliary tree anatomy and evaluating biliary disorders. However, to date, there are a limited number of studies that have focused on the impact of this technique. Aims: We aimed to evaluate the additional role of contrast enhanced MR cholangiography (MRC and compare contrast enhanced MRC with T2-weighted (w magnetic resonance cholangiopancreatography (MRCP in the diagnosis of biliary disorders. Study Design: Diagnostic accuracy study. Methods: The T2w-MRCP and contrast enhanced MRC sequences of 31 patients whose gold standard test results were available were scored visually for the existence of pathological findings with regard to any of the biliary diseases. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA was used as the contrast agent. The correlation values were determined according to the statistical analysis made from those scores and the sensitivity, specificity and accuracy values of each sequence were detected as well. Results: We detected that the correlation values with gold standard methods of contrast enhanced MRC sequences were significantly higher than the ones of T2w-MRCP sequences. The correlation ratios of T2w-MRCP sequences were between 26 and 34%, while those for contrast enhanced MRC sequences were between 81 and 83% for the first reader and the correlation ratios of T2w-MRCP sequences were between 10 and 61%, whereas those of contrast enhanced MRC were between 79 and 81% for the second reader The mean sensitivity, specificity and accuracy values of T2w-MRCP sequences were 14.3-42.5%, 85-89.2% and 59.3-72.5%, respectively, while the mean sensitivity, specificity and accuracy values of contrast enhanced MRC sequences were 100%, 86.7% and 93.2-93.3%, respectively. Conclusion: We suggest that obtaining of contrast enhanced MRC sequences in addition to the T2w-MRCP can be useful in

Gadopentetate dimeglumine-enhanced MR cholangiopancreatography in infants with cholestasis

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Lee, Mi-Jung; Kim, Myung-Joon [Yonsei University, College of Medicine, Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Seoul (Korea, Republic of); Severance Pediatric Liver Disease Research Group, Seoul (Korea, Republic of); Yoon, Choon-Sik [Yonsei University, College of Medicine, Department of Radiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Chung, Yong Eun [Yonsei University, College of Medicine, Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Seoul (Korea, Republic of); Han, Seok Joo [Yonsei University, College of Medicine, Department of Pediatric Surgery, Severance Children' s Hospital, Seoul (Korea, Republic of); Severance Pediatric Liver Disease Research Group, Seoul (Korea, Republic of); Koh, Hong [Yonsei University, College of Medicine, Department of Pediatric Gastroenterology, Hepatology, and Nutrition, Severance Children' s Hospital, Seoul (Korea, Republic of); Severance Pediatric Liver Disease Research Group, Seoul (Korea, Republic of)

2011-04-15

Biliary atresia (BA) is a progressive, obliterative cholangiopathy that occurs in neonates with hepatic portoenterostomy the treatment of choice, but early surgery is important for optimum outcomes. MRI, including MR cholangiopancreatography (MRCP) may be a diagnostically useful alternative to US, but the heavily T2-weighted sequences used include not only bile duct signals, but also other heterogeneously high signal intensities from surrounding structures. To evaluate the effects of gadolinium when used to decrease background signal intensity on T2-weighted MR cholangiopancreatography (MRCP) in infants and to evaluate the qualitative improvement of the depiction of the common bile duct (CBD) for evaluating neonatal cholestasis. Our Institutional Review Board approved this prospective study. MRCP was performed with gadopentetate dimeglumine injection using a 1.5-T scanner. Pre- and postcontrast MRCP images were compared. Forty-nine infants (male:female = 21:28; age 0-12 months, mean 2.3) were included. The final diagnoses were biliary atresia (BA) in 28 cases and non-BA in 21. Quantitative analysis was conducted using region-of-interest measurements of mean signal intensities of the liver, pancreatic head and gallbladder (if defined). Qualitative analysis was performed by four radiologists who subjectively scored image confidence in the presence of CBD on a 4-point scale (0 for definitely absent, 1 for probably absent, 2 for probably present, and 3 for definitely present). The signal-to-noise ratios were significantly decreased in the liver and pancreatic head after contrast medium enhancement (mean 5.7{yields}4.0 in liver and mean 44.9{yields}12.7 in the pancreatic head; P < 0.0001), and this finding was constant in both the BA and the non-BA group. The mean confidence score in the presence of CBD decreased in the BA group (0.9{yields}0.5; P < 0.0001), but did not change significantly in the non-BA group (2.0{yields}2.1; P = 0.459) after contrast medium

Automatic gallbladder segmentation using combined 2D and 3D shape features to perform volumetric analysis in native and secretin-enhanced MRCP sequences.

Science.gov (United States)

Gloger, Oliver; Bülow, Robin; Tönnies, Klaus; Völzke, Henry

2017-11-24

We aimed to develop the first fully automated 3D gallbladder segmentation approach to perform volumetric analysis in volume data of magnetic resonance (MR) cholangiopancreatography (MRCP) sequences. Volumetric gallbladder analysis is performed for non-contrast-enhanced and secretin-enhanced MRCP sequences. Native and secretin-enhanced MRCP volume data were produced with a 1.5-T MR system. Images of coronal maximum intensity projections (MIP) are used to automatically compute 2D characteristic shape features of the gallbladder in the MIP images. A gallbladder shape space is generated to derive 3D gallbladder shape features, which are then combined with 2D gallbladder shape features in a support vector machine approach to detect gallbladder regions in MRCP volume data. A region-based level set approach is used for fine segmentation. Volumetric analysis is performed for both sequences to calculate gallbladder volume differences between both sequences. The approach presented achieves segmentation results with mean Dice coefficients of 0.917 in non-contrast-enhanced sequences and 0.904 in secretin-enhanced sequences. This is the first approach developed to detect and segment gallbladders in MR-based volume data automatically in both sequences. It can be used to perform gallbladder volume determination in epidemiological studies and to detect abnormal gallbladder volumes or shapes. The positive volume differences between both sequences may indicate the quantity of the pancreatobiliary reflux.

Single dose oral ranitidine improves MRCP image quality: a double-blind study

International Nuclear Information System (INIS)

Bowes, M.T.; Martin, D.F.; Melling, A.; Roberts, D.; Laasch, H.-U.; Sukumar, S.; Morris, J.

2007-01-01

Aim: To investigate the possibility of whether a single 300 mg dose of ranitidine given orally 2-3 h before magnetic resonance cholangiopancreatography (MRCP) could reduce the signal from the stomach and duodenum, and thus increase the conspicuousness of the biliary tree. Materials and methods: Thirty-five volunteers (22 female, 13 male), (age range 21-50) were underwent MRCP in a double-blind, placebo-controlled, randomized, crossover trial on a Philips Intera 1.5 T machine using a phased array surface coil. Imaging was carried out in the coronal oblique plane. Six 40 mm sections were acquired at varying angles to delineate the biliary tree and pancreatic duct. The 70 examinations were blindly scored by three consultants experienced in cholangiography. Results: After ranitidine administration there was a significant decrease in signal from the stomach (mean = 17.7, p = 0.0005, CI 10, 25.3) and duodenum (mean = 18.4, p = 0.0005, 95%CI 9.6, 27.1) with a significant increase in conspicuousness of the distal common duct (mean = 7.7, p = 0.033, 95%CI 0.7, 14.7) and proximal common duct (mean = 8.7, p = 0.010 CI 2.2, 15.2). There were no adverse effects. Conclusion: Oral ranitidine is a cheap and effective agent to decrease signal from the upper gastrointestinal tract and to improve visibility of the biliary tree

Diagnostic value of high strength MRCP in the obstructive jaundice

International Nuclear Information System (INIS)

Yang Yang; Dong Yuhai; Yin Jie; Lv Guoyi

2007-01-01

Objective: To evaluate the diagnostic value of high strength MRCP in patients with obstructive jaundice. Methods: Routine MRI and MRCP examination on 161 patients with obstructive jaundice were carded out with 1.5T Siemens super-conductive magnetic resonance machine. Of them, 103 cases were benign lesions and 58 were malignant after surgical and ERCP pathological confirmation. Results: The diagnostic accuracy of MRCP was 100%, with the qualitative diagnostic accuracy at 90.2%. Conclusion: MRCP was the best method in diagnosing patients with obstructive jaundice, the concerned performances of MRCP could provide the dependable basis for surgical operation project. (authors)

Imaging features of portal biliopathy: Frequency of involvement patterns with emphasis on MRCP

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Ozkavukcu, Esra [Ankara University School of Medicine, Department of Radiology (Turkey)], E-mail: eozkavukcu@gmail.com; Erden, Ayse; Erden, Ilhan [Ankara University School of Medicine, Department of Radiology (Turkey)

2009-07-15

Purpose: To investigate the imaging features of portal biliopathy with emphasis on MR cholangiopancreatography (MRCP). The ancillary vascular findings of portal biliopathy were also evaluated by accompanying MR portography, dynamic contrast-enhanced (CE) CT, and dynamic CE MRI studies. Materials and methods: Sixteen patients with portal cavernoma were included in the study. Patients had undergone MRCP (n = 16) studies accompanied by MR portography (n = 13), dynamic CE CT (n = 3) or dynamic CE MRI (n = 2) of the liver. Two patients had undergone both dynamic CE CT and dynamic CE MRI. Two radiologists evaluated all the examinations together, retrospectively. MRCP images were analyzed for the presence of biliary stenosis, upstream (prestenotic) dilatation, wavy appearance of the bile ducts, angulation of the common bile duct (CBD), and choledocholithiasis. MR portography, dynamic CE CT and dynamic CE MRI studies were evaluated for the existence of portal cavernomas, and the presence of gall bladder/choledochal varices. Results: All patients had signs of portal biliopathy on MRCP. Frequencies of the biliary findings on MRCP were as follows: biliary stenosis, 93.7%; upstream dilatation, 68.7%; wavy appearance of the biliary tree, 87.5%; angulation of the CBD, 75%. None of the patients had choledocholithiasis. Frequencies of the ancillary vascular findings detected on CE studies were as follows: gall bladder varices, 100%, choledochal varices, 93.7%. Conclusion: MRCP features of portal biliopathy in order to their frequencies were as follows: biliary stenosis, wavy appearance of the bile ducts, angulation of the CBD, and upstream dilatation of the bile ducts.

Usefulness of magnetic resonance cholangiography in the diagnosis of biliary tract lesions in patients with suspected complication following cholecystectomy; Valor da colangiopancreatografia por ressonancia magnetica no diagnostico de lesoes das vias biliares em pacientes com suspeita de complicacao pos-colecistectomia

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Cecin, Alexandre de Oliveira [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil); Goldman, Suzan Menasce; Caetano, Simone; Rosas, George de Queiroz; Coelho, Rafael Darahem de Souza [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem; Lobo, Edson Jose [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Gastroenterologia Cirurgica; Abdalla, Nitamar; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem

2005-01-15

Objective: to determine the usefulness of magnetic resonance cholangiopancreatography (MRCP) in the diagnoses of bile duct injuries following cholecystectomy. Material and method: MRCP was retrospectively evaluated in 40 patients with suspected bile duct injury after laparoscopic or conventional cholecystectomy. Eight of these patients had been submitted to biliary reconstruction. All patients were symptomatic (jaundice, fever and chills, weight loss and abdominal pain). The scans were independently reviewed by two radiologists. The results were confirmed by surgery, percutaneous drainage, endoscopic retrograde cholangiopancreatography and clinical follow-up. The level and severity of bile duct injury were rated according to the Bismuth classification. Results: in a total of 40 symptomatic patients, 10 (25%) had normal findings on MRCP; Postoperative complications were seen in 29 (72.5%) patients, seven of them with more than one finding. Pancreatic head neoplasia was diagnoses in one patient. The most frequent finding was sclerosing (41.4%) followed by biliary duct stenosis (34.5%), residual or recurrent biliary stones (31.0%) and fluid collections (17.2%). The images obtained by MRCP were considered of good quality. Conclusion: MRCP is an effective method for the evaluation of patients with suspected postcholecystectomy biliary tract complications. (author)

The primary applications of Gd-DTPA as an oral negative gastrointestinal contrast agent for MRCP

International Nuclear Information System (INIS)

Chen Yanping; Zhang Xuelin; Cheng Guanxun; Chang Renmin; Zhang Yuzhong; Cang Peng; Xia Qiong

2003-01-01

Objective: Using oral Gd-DTPA as a negative contrast agent to null the bowel signal during MR cholangiopancreatography (MRCP) to improve the quality of MRCP. Methods: A phantom study was performed to select the optimal concentration of Gd-DTPA to be used as an oral negative contrast agent in MRCP. 15 patients suspected of biliary tract and pancreatic disease were performed with MRCP before and after using 250 ml oral contrast agents (1:5 diluted Gd-DTPA, 1.488 g/L). All MR images were acquired using a 1.5 T whole body MR scanner (Vision Plus, Siemens). MRCP was acquired using two-dimensional single slice fast spin-echo sequence and HASTE (half-fourier acquisition single-shot fast spin echo) sequence. Results: The phantom study showed that the dilution ratio 1:5 of Gd-DTPA oral contrast agent was best in decreasing the signal intensity both in T 2 WI (59.3%) and in HASTE sequence (82.45%). All the dilution ratio of Gd-DTPA oral contrast agent decreased the signal intensity up to 90% on single slice MRCP. In all the patients the high signal intensity from the stomach and intestinal fluid was completely suppressed. The depictions of common bile duct and pancreatic duct were markedly improved by the oral contrast agent (P<0.05). Conclusion: 1:5 diluted (1.488 g/L) oral MR contrast agent Gd-DTPA can be an effective and safe negative contrast agent in eliminating signal intensity of the gastrointestinal tract, thus improving the depiction of the biliary system in MRCP

The role of multi-detector-row computed tomograph in the diagnosis of intraductal papillary-mucinous tumors of the pancreas in comparison to endoscopic retrograde pancreatography, endoscopic ultrasonography, magnetic resonance cholangiopancreatography

International Nuclear Information System (INIS)

Arikawa, Shunji; Uchida, Masafumi; Shinagawa, Masaharu

2007-01-01

Thirty patients with intraductal papillary-mucinous tumor (IPMT) of the pancreas underwent multidetector-row CT (MD-CT) in addition to endoscopic retrograde pancreatography (ERP), and, in 27 cases magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasonography (EUS). The usefulness of MD-CT was investigated by comparing various imaging methods of the communication from the main pancreatic duct (MPD) to patulous/bulging papilla in addition to the indices for benign or malignant disease, the degree of dilation of the MPD, localization and size of cystic lesions, and presence or absence of neoplastic lesions, such as thickened walls and septa, intramural nodule, solid mass. With MD-CT, dilation of the MPD and localization and size of cystic lesions were accurately assessed, even in patients with obstruction of the main pancreatic duct in whom ERP was difficult to perform regardless of the presence or absence of massive amount of mucus. MD-CT with reconstructive imaging, such as multiplanar reformation (MPR) imaging and curred planar reformation (CPR) imaging, allowed us to assess communication with the MPD and patulous/bulging papilla easier than MRCP. In our study, MD-CT was useful in the evaluation of thickened walls and septa that are predictive factors of malignancy in IPMT. (author)

Quantification of pancreatic exocrine function with secretin-enhanced magnetic resonance cholangiopancreatography: normal values and short-term effects of pancreatic duct drainage procedures in chronic pancreatitis. Initial results

International Nuclear Information System (INIS)

Bali, M.A.; Sztantics, A.; Metens, T.; Matos, C.; Arvanitakis, M.; Delhaye, M.; Deviere, J.

2005-01-01

The aim of this study was to quantify pancreatic exocrine function in normal subjects and in patients with chronic pancreatitis (CP) before and after pancreatic duct drainage procedures (PDDP) with dynamic secretin-enhanced magnetic resonance (MR) cholangiopancreatography (S-MRCP). Pancreatic exocrine secretions [quantified by pancreatic flow output (PFO) and total excreted volume (TEV)] were quantified twice in ten healthy volunteers and before and after treatment in 20 CP patients (18 classified as severe, one as moderate, and one as mild according to the Cambridge classification). PFO and TEV were derived from a linear regression between MR-calculated volumes and time. In all subjects, pancreatic exocrine fluid volume initially increased linearly with time during secretin stimulation. In controls, the mean PFO and TEV were 6.8 ml/min and 97 ml; intra-individual deviations were 0.8 ml/min and 16 ml. In 10/20 patients with impaired exocrine secretions before treatment, a significant increase of PFO and TEV was observed after treatment (P<0.05); 3/20 patients presented post-procedural acute pancreatitis and a reduced PFO. The S-MRCP quantification method used in the present study is reproducible and provides normal values for PFO and TEV in the range of those obtained from previous published intubation studies. The initial results in CP patients have demonstrated non-invasively a significant short-term improvement of PFO and TEV after PDDP. (orig.)

Secretin-stimulating MRCP in patients with pancreatobiliary maljunction and occult pancreatobiliary reflux: direct demonstration of pancreatobiliary reflux

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Motosugi, Utaroh; Ichikawa, Tomoaki; Araki, Tsutomu [University of Yamanashi, Department of Radiology, Chuo-shi, Yamanashi (Japan); Kitahara, Fumiaki; Sato, Tadashi [University of Yamanashi, First Department of Internal Medicine, Chuo-shi, Yamanashi (Japan); Itakura, Jun; Fujii, Hideki [University of Yamanashi, First Department of Surgery, Chuo-shi, Yamanashi (Japan)

2007-09-15

We propose the hypothesis that the enlargement of the common bile duct (CBD) or gallbladder (GB) that is occasionally demonstrated on magnetic resonance cholangiopancreatography (MRCP) after secretin stimulation is caused by pancreatobiliary reflux. Recently, occult pancreatobiliary reflux (OPR) has been demonstrated in patients without morphological pancreatobiliary maljunction (MPBM). The aim of this study was to evaluate the efficacy of secretin-stimulating MRCP (SMRCP) in the diagnosis of pancreatobiliary reflux. The study included 14 patients with MPBM and 32 patients with a normal pancreatobiliary junction. OPR was evaluated by bile collection and diagnosed in seven of the 32 patients. All the patients underwent SMRCP; the related findings were considered positive when enlargement of the CBD or GB was observed. Positive findings on SMRCP were observed in all MPBM patients. In the patients with normal pancreatobiliary junction, there was significant difference between the mean amylase levels in the patients with positive and negative SMRCP findings (mean, 4,755.7 and 29.7 IU/l). The sensitivity and specificity of SMRCP for diagnosing OPR was 85.7% and 68.0%, respectively. SMRCP provides a non invasive method for excluding PBR and can identify patients who could benefit from bile duct sampling to diagnose OPR. (orig.)

On the appearance of bile in clinical MR cholangiopancreatography

International Nuclear Information System (INIS)

Haakansson, K.; Christoffersson, J.O.; Leander, P.; Ekberg, O.; Haakansson, H.O.

2002-01-01

Purpose: To study the appearance of bile in clinical MR cholangiopancreatography (MRCP) with special reference to its chemical and physical properties. Material and Methods: Gallbladder bile was collected during surgery from 38 patients and studied with respect to chemical constituents. The relaxation rates 1/T1 and 1/T2 of bile were also determined in vitro. In 16 of these 38 patients, abdominal imaging was performed using MRCP as well as T1-weighted GE sequences. Results: For 9 of the 13 chemical parameters studied, a positive significant correlation with 1/T1 as well as 1/T2 was found. The median relaxation rates 1/T1 and 1/T2 were 0.76 and 1.48/s, respectively. The corresponding ranges were 0.38-3.13/s and 0.70-5.75/s, respectively. On the MRCP images a few patients showed gallbladder of poor visibility due to low signal-to-noise ratio. This coincided with a high relaxation rate 1/T2 of bile. On the T1-weighted GE sequences a few patients showed hyperintense gallbladder relative to liver, coinciding with high relaxation rates 1/T1 of bile. Conclusion: Bile was found to show a large interindividual variation with respect to relaxation rates 1/T1 and 1/T2. The relaxation rates increased with increasing amounts of substances in the bile. For some patients (11%) MRCP imaging is unsuccessful due to high relaxation rate of bile

The value of adding conventional MR imaging to MR cholangiopancreatography in differentiation of benign and malignant causes of postoperative disorders

International Nuclear Information System (INIS)

Sun Changjin; Zhou Xiangping; Song Bin; Chen Xian; Liu Rongbo; Yan Zhihan; Xiong Yan

2003-01-01

Objective: To determine the value of conventional T 1 - and T 2 -weighted images and gadolinium-enhanced magnetic resonance (MR) images as a supplement to MR cholangiopancreatography (MRCP) in differentiation of benign from malignant causes of postoperative disorders in the biliary ductal system. Methods: Sixty-one patients with postoperative disorders in the biliary ductal system with proved causes underwent MRCP, conventional T 1 - and less heavily T 2 -weighted images, as well as gadolinium-enhanced images. Two radiologists independently reviewed MRCP images alone, MRCP plus nonenhanced T 1 - and T 2 -weighted images, and MRCP plus nonenhanced and gadolinium-enhanced images. The results of MR findings were compared with that of the surgical findings and the pathology. Results: For the diagnosis of postoperative disorders only with MRCP images, the sensitivity, specificity, and accuracy was 42.1%, 80.9% and 68.9% for radiologist 1 and 47.4%, 85.7%, and 73.8% for radiologist 2, respectively. When MRCP images were interpreted with T 1 - and T 2 -weighted images, the sensitivity, specificity, and accuracy was 78.9%, 92.9% and 88.5% for radiologist 1 and, 78.9%, 95.2%, and 90.2% for radiologist 2, respectively. When MRCP images were combined with both nonenhanced T 1 - and T 2 -weighted images and enhanced MR images, the sensitivity, specificity, and accuracy was 84.2%, 95.2% and 91.8% for radiologist 1 and 84.2%, 97.6%, and 93.4% for radiologist 2, respectively. There was no significant difference between the 2 readers (P>0.05). For differentiation of benign from malignant causes of postoperative disorders, the area under the receiver operating characteristic curve (Az) was significantly larger for MRCP images interpreted with T 1 - and T 2 weighted images (0.907 for reader 1, 0.920 for reader 2) than for MRCP images alone (0.682 reader 1, 0.714 for reader 2) (P 1 - and T 2 -weighted images did not significantly increase the accuracy (Az = 0.948 for reader 1, 0

Comparison of respiratory-triggered 3-D fast spin-echo and single-shot fast spin-echo radial slab MR cholangiopancreatography images in children

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Chavhan, Govind B.; Almehdar, Abeer; Gupta, Sumeet [The Hospital for Sick Children and University of Toronto, Department of Diagnostic Imaging, Toronto (Canada); Moineddin, Rahim [University of Toronto, Department of Family and Community Medicine, Toronto (Canada); Babyn, Paul S. [Royal University Hospital, Department of Medical Imaging, Saskatoon (Canada)

2013-09-15

The two most commonly performed magnetic resonance cholangiopancreatography (MRCP) sequences, 3-D fast spin-echo (3-D FSE) and single-shot fast spin-echo radial slabs (radial slabs), have not been compared in children. The purpose of this study was to compare 3-D FSE and radial slabs MRCP sequences on a 3-T scanner to determine their ability to show various segments of pancreaticobiliary tree and presence of artifacts in children. We reviewed 79 consecutive MRCPs performed in 74 children on a 3-T scanner. We noted visibility of major ducts on 3-D FSE and radial slabs. We noted the order of branching of ducts in the right and left hepatic ducts and the degree of visibility of the pancreatic duct. Statistical analysis was performed using McNemar and signed rank tests. There was no significant difference in the visibility of major bile ducts and the order of branching in the right hepatic lobe between sequences. A higher order of branching in the left lobe was seen on radial slabs than 3-D FSE (mean order of branching 2.82 versus 2.27; P-value = 0.0002). The visibility of pancreatic duct was better on radial slabs as compared to 3-D FSE (mean value of 1.53 vs. 0.90; P-value < 0.0001). 3-D FSE sequence was artifact-free in 25/79 (31.6%) MRCP exams as compared to radial slabs, which were artifact-free in 18/79 (22.8%) MRCP exams (P-value = 0.0001). There is no significant difference in the visibility of major bile ducts between 3-D FSE and radial slab MRCP sequences at 3-T in children. However, radial slab MRCP shows a higher order of branching in the left hepatic lobe and superior visibility of the pancreatic duct than 3-D FSE. (orig.)

A prospective, comparative study of magnetic resonance cholangipancreatography and direct cholangiography in the diagnosis of biliary diseases

International Nuclear Information System (INIS)

Fernandez, E.; Falco, J.; Martin, J.; Brullet, E.; Campo, R.; Espinos, J.; Darnell, A.

2001-01-01

To assess the sensitivity and specificity of magnetic resonance cholangiopancreatography (MRCP) as a noninvasive diagnostic technique, comparing it with endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTHC) in the diagnosis of biliary disease, focusing particularly on patients with choledocholithiasis. Between June 1997 and february 1998, 109 patients referred by the Corporacio Sanitaria del Parc Tauli and the Hospital Mutua de terrasa in Barcelona, Spain were evaluated. MRCP and ERCP or PTHC were performed in every case, always in that order and separated by a maximum of 7 days. Twenty-four patients were excluded from the study for different reasons, leaving a series of 85 patients. All the studies were performed with a 1-Tesla Siemens Magneton Impact Expert using half-fourier single-short turbo spin-echo (HASTE) and rapid acquisition with relaxation enhancement (RARE) methods in several coronal and axial planes. The MRCP readings were carried out by consensus by two radiologists who are experts in the assessment of diseases of the digestive tract. In this series of 85 patients; MCRP showed a sensitivity of 98.4%, a specificity of 94.7%, a positive predictive value of 98.4% and a negative predictive value of 94.7% for the detection of biliary diseases. For the detection choledocholithiasis, these values were 100%, 89.5%, 88% and 100%, respectively. MRCP is extremely reliable in the diagnosis of biliary diseases, especially in cases of choledocholithiasis. Its high negative predictive value obviates the need for other invasive diagnostic tests. (Author) 30 refs

MR cholangiopancreatography. Comparison of images obtained with 1.0 and 1.5 tesla units

International Nuclear Information System (INIS)

Yasui, Masayasu; Ito, Katsuyoshi; Koike, Shinji; Matsunaga, Naofumi

2002-01-01

The purpose of this study was to compare the image quality and visualization obtained in MR cholangiopancreatography (MRCP) using different high-field strength (1.0 vs. 1.5 Tesla) MR units and to assess the effect of field strength on MRCP. This study population included 10 healthy volunteers and 37 patients suspected of having pancreatobiliary diseases. MRCP images were obtained using two MR units with different high-field strengths (1.0 and 1.5 Tesla), with half-Fourier acquisition single-shot turbo spin-echo (HASTE) and rapid acquisition by relaxation enhancement (RARE) sequences. The image quality and visualization of each portion of the pancreatobiliary system were graded and recorded using a four-point scale. Additionally, the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured. The SNR and CNR in HASTE sequences acquired with the 1.5 Tesla (T) unit were significantly higher than those acquired with the 1.0 T unit (p=0.001). In qualitative analysis, there were no statistically significant differences in image quality or visualization of the ducts in either HASTE or RARE sequences between 1.0 T and 1.5 T. Our study showed that visual image quality provided by MRCP was equivalent at 1.0 and 1.5 T. (author)

Santorinicele: secretin-enhanced magnetic resonance cholangiopancreatography findings before and after minor papilla sphincterotomy

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Boninsegna, Enrico; Manfredi, Riccardo; Ventriglia, Anna; Negrelli, Riccardo; Pedrinolla, Beatrice; Mehrabi, Sara; Pozzi Mucelli, Roberto [University of Verona, Department of Radiology - Policlinico G.B. Rossi, Verona (Italy); Gabbrielli, Armando [University of Verona, Department of Medicine - Policlinico G.B. Rossi, Verona (Italy)

2015-08-15

To evaluate secretin-enhanced MRCP (S-MRCP) findings of patients with pancreas divisum and Santorinicele, before and after minor papilla sphincterotomy. S-MRCP examinations of 519 patients with suspected pancreatic disease were included. Size of the main pancreatic duct, presence and calibre of Santorinicele were evaluated. Duodenal filling was assessed on dynamic images. After sphincterotomy the same parameters and the clinical findings were re-evaluated. Pancreas divisum was depicted in 55/519 patients (11 %) by MRCP and an additional 26/519 by S-MRCP (total 81/519, 16 %). Santorinicele was detected in 7/81 patients (8.6 %) with pancreas divisum by MRCP and an additional 20/81 by S-MRCP (total 27/81, 33 %). Dorsal duct in patients with Santorinicele was significantly larger in the head compared with patients with only pancreas divisum (p < 0.01), in basal conditions (average 2.4 versus 1.9 mm) and after secretin administration (average 3.0 versus 2.4 mm). Duodenal filling was impaired in 11/27 patients (41 %) with Santorinicele. After sphincterotomy significant reduction in size of Santorinicele (-33 %) and dorsal duct (-17 %), increase of pancreatic juice and symptoms improvement were observed. Secretin administration increases the accuracy of MRCP in detecting Santorinicele and demonstrates the impaired duodenal filling. S-MRCP is useful to assess results of sphincterotomy. (orig.)

Conservative treatment of bronchobiliary fistula evaluated with magnetic resonance imaging

Directory of Open Access Journals (Sweden)

Adžić-Vukičević Tatjana N.

2015-01-01

Full Text Available Introduction. Bronchobiliary fistula (BBF is a pathological communication between the bronchial system and the biliary tree that presents with bilioptysis. Many conditions can cause its development. There is still no optimal therapy for BBF. Conservative treatment is rarely indicated, as was published before in a few cases. Case report. We presented a 71-year-old Caucasian Serbian woman with BBF secondary to previous laparotomy due to multiple echinococcus liver cysts. The diagnosis was established by the presence of bilirubin and bile acids in sputum and magnetic resonance cholangiopancreatography (MRCP. A repeat MRCP performed after conservative procedure, did not reveal fistulous communication. Conclusion. We suggest that in small and less severe fistulas between the biliary and the bronchial tract, conservative treatment may be used successfully, and invasive treatment methods are not needed in all patients.

Primary biliary cirrhosis: Evaluation with T2-weighted MR imaging and MR cholangiopancreatography

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Haliloglu, Nuray [Ankara University, Faculty of Medicine, Department of Radiology, Ibni Sina Hospital, 06100 Ankara (Turkey)], E-mail: nurayunsal2@hotmail.com; Erden, Ayse; Erden, Ilhan [Ankara University, Faculty of Medicine, Department of Radiology, Ibni Sina Hospital, 06100 Ankara (Turkey)

2009-03-15

Purpose: The aim of this retrospective study is to evaluate the role of T2-weighted MR imaging (MRI) and MR cholangiopancreatography (MRCP) findings in the diagnosis of primary biliary cirrhosis (PBC). Materials and methods: The following T2-weighted MRI and MRCP findings: segmental hepatic atrophy/hypertrophy, irregular liver surface, parenchymal lace-like fibrosis, rounded low signal intensity lesions centering portal vein branches (periportal halo sign), periportal hyperintensity (cuffing), splenomegaly, ascites, lymphadenopathy, venous collaterals, and the configuration of intrahepatic biliary ducts were reviewed for their diagnostic significance by two observers in 13 female patients (mean age: 49 years) with PBC. Discordant readings of the observers were resolved at consensus. Results: When parenchymal lace-like fibrosis and periportal halo sign were seen together the sensitivity of T2-weighted MR images was 69%. In six cases periportal hyperintensity (cuffing) and periportal halo sign were seen together. Segmental hypertrophy was present in nine patients and hepatic surface irregularity due to regenerative nodules were present in 10 patients. Lymphadenopathy was seen in 10, splenomegaly was seen in 5, collateral vascular structures were seen in 2 and minimal perihepatic free fluid was seen in 2 patients. MRCP images revealed various mild irregularity in the intrahepatic bile ducts in 8 patients and focal narrowing at the common bile duct level in 1 patient. Conclusion: MRI and MRCP may support the clinical and laboratory findings of PBC even in the early stages of the disease. MRI can also be a choice of method for the recommended prolonged follow up.

Primary biliary cirrhosis: Evaluation with T2-weighted MR imaging and MR cholangiopancreatography

International Nuclear Information System (INIS)

Haliloglu, Nuray; Erden, Ayse; Erden, Ilhan

2009-01-01

Purpose: The aim of this retrospective study is to evaluate the role of T2-weighted MR imaging (MRI) and MR cholangiopancreatography (MRCP) findings in the diagnosis of primary biliary cirrhosis (PBC). Materials and methods: The following T2-weighted MRI and MRCP findings: segmental hepatic atrophy/hypertrophy, irregular liver surface, parenchymal lace-like fibrosis, rounded low signal intensity lesions centering portal vein branches (periportal halo sign), periportal hyperintensity (cuffing), splenomegaly, ascites, lymphadenopathy, venous collaterals, and the configuration of intrahepatic biliary ducts were reviewed for their diagnostic significance by two observers in 13 female patients (mean age: 49 years) with PBC. Discordant readings of the observers were resolved at consensus. Results: When parenchymal lace-like fibrosis and periportal halo sign were seen together the sensitivity of T2-weighted MR images was 69%. In six cases periportal hyperintensity (cuffing) and periportal halo sign were seen together. Segmental hypertrophy was present in nine patients and hepatic surface irregularity due to regenerative nodules were present in 10 patients. Lymphadenopathy was seen in 10, splenomegaly was seen in 5, collateral vascular structures were seen in 2 and minimal perihepatic free fluid was seen in 2 patients. MRCP images revealed various mild irregularity in the intrahepatic bile ducts in 8 patients and focal narrowing at the common bile duct level in 1 patient. Conclusion: MRI and MRCP may support the clinical and laboratory findings of PBC even in the early stages of the disease. MRI can also be a choice of method for the recommended prolonged follow up.

A prospective, comparative study of magnetic resonance cholangipancreatography and direct cholangiography in the diagnosis of biliary diseases; Estudio propsective comparativo en el diagnostico de la patologia biliar. Colangiopancreatografia por resonancia magnetica frente a colangiografia directa

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Fernandez, E.; Falco, J.; Martin, J.; Brullet, E.; Campo, R.; Espinos, J.; Darnell, A.

2001-07-01

To assess the sensitivity and specificity of magnetic resonance cholangiopancreatography (MRCP) as a noninvasive diagnostic technique, comparing it with endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTHC) in the diagnosis of biliary disease, focusing particularly on patients with choledocholithiasis. Between June 1997 and february 1998, 109 patients referred by the Corporacio Sanitaria del Parc Tauli and the Hospital Mutua de terrasa in Barcelona, Spain were evaluated. MRCP and ERCP or PTHC were performed in every case, always in that order and separated by a maximum of 7 days. Twenty-four patients were excluded from the study for different reasons, leaving a series of 85 patients. All the studies were performed with a 1-Tesla Siemens Magneton Impact Expert using half-fourier single-short turbo spin-echo (HASTE) and rapid acquisition with relaxation enhancement (RARE) methods in several coronal and axial planes. The MRCP readings were carried out by consensus by two radiologists who are experts in the assessment of diseases of the digestive tract. In this series of 85 patients; MCRP showed a sensitivity of 98.4%, a specificity of 94.7%, a positive predictive value of 98.4% and a negative predictive value of 94.7% for the detection of biliary diseases. For the detection choledocholithiasis, these values were 100%, 89.5%, 88% and 100%, respectively. MRCP is extremely reliable in the diagnosis of biliary diseases, especially in cases of choledocholithiasis. Its high negative predictive value obviates the need for other invasive diagnostic tests. (Author) 30 refs.

MRI of oriental cholangiohepatitis

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Wani, N.A., E-mail: ahmad77chinar@gmail.co [Department of Radiodiagnosis and Imaging, Sher-I-Kashmir Institute of Medical Sciences (SKIMS), Srinagar (India); Robbani, I.; Kosar, T. [Department of Radiodiagnosis and Imaging, Sher-I-Kashmir Institute of Medical Sciences (SKIMS), Srinagar (India)

2011-02-15

Oriental cholangiohepatitis (OCH) also called recurrent pyogenic cholangitis is characterized by intrahepatic duct calculi, strictures, and recurrent infections. In turn cholangitis can result in multiple hepatic abscesses, further biliary strictures, and in severe cases, progressive hepatic parenchymal destruction, cirrhosis, and portal hypertension. Magnetic resonance cholangiopancreatography (MRCP) and conventional T1-weighted (T1 W) and T2-weighted (T2 W) magnetic resonance imaging (MRI) findings have been described in patients with OCH. MRCP findings include duct dilation, strictures, and calculi. MRCP can help to localize the diseased ducts and determine the severity of involvement. T1 and T2 W sequences reveal the parenchymal changes of atrophy, abscess formation, and portal hypertension in addition to calculi. Post-treatment changes are also well depicted using MRI. Comprehensive, non-invasive assessment is achieved by using conventional MRI and MRCP in OCH providing a roadmap for endoscopic or surgical management.

Pancreatic adenocarcinoma: combination of MR imaging, MR angiography and MR cholangiopancreatography for the diagnosis and assessment of resectability

International Nuclear Information System (INIS)

Catalano, C.; Pavone, P.; Laghi, A.; Panebianco, V.; Scipioni, A.; Fanelli, F.; Brillo, R.; Passariello, R.

1998-01-01

The purpose of this study was to determine the possibility of integrating MR cholangiopancreatography (MRCP) and MR angiography (MRA) to conventional MR images in the diagnosis and assessment of resectability of pancreatic adenocarcinoma. Twenty-three patients with pancreatic adenocarcinoma were prospectively examined with MR. Conventional MR images were acquired in all patients. Three-dimensional MRCP and MRA images were acquired in all patients with suspected biliary and vascular involvement. Acquisition time was less than 45 min in all cases. Images were independently evaluated by two radiologists, with final reading decided by consensus among readers. Diagnosis was confirmed with surgery in 16 patients and with percutaneous biopsy in 7. Concordance among readers was high with a kappa value of 0.83. Pancreatic adenocarcinoma was observed in all patients. Correct assessment of unresectability due to vascular involvement was found in 22 of 23 patients. Biliary obstruction was evident in 13 patients, involving the biliary and pancreatic ducts in 9 and the biliary ducts only in 4. Technical advances permit extensive use of MRI in the evaluation of abdominal pathologies. The combination of MR imaging, MRCP, and MRA can provide sufficient information for the diagnosis and assessment of resectability of pancreatic adenocarcinoma, which otherwise would require three different exams. (orig.)

Pancreatic duct abnormalities in focal autoimmune pancreatitis: MR/MRCP imaging findings

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Negrelli, Riccardo; Manfredi, Riccardo; Pedrinolla, Beatrice; Boninsegna, Enrico; Ventriglia, Anna; Mehrabi, Sara; Pozzi Mucelli, Roberto [G.B. Rossi University Hospital, University of Verona, Department of Radiology, Verona (Italy); Frulloni, Luca [Universita di Verona, Department of Gastroenterology, Policlinico G.B. Rossi, Verona (Italy)

2014-08-09

To evaluate the magnetic resonance (MR) imaging-MR cholangiopancreatographic (MRCP) findings of focal forms of autoimmune pancreatitis (AIP) to describe ductal involvement at diagnosis. MR examinations of 123 patients affected by AIP were analysed. We included 26 patients who satisfied International Consensus Diagnostic Criteria and were suffering from focal AIP. Image analysis included: site of parenchymal enlargement, main pancreatic duct (MPD) diameter, MPD stenosis, stricture length, presence of upstream dilation within the stricture, signal intensity, and pancreatic enhancement. Signal intensity abnormalities were localized in the head in 10/26 (38.5 %) and in the body-tail in 16/26 (61.5 %) patients. MRCP showed a single MPD stenosis in 12/26 (46.1 %) and multiple MPD stenosis in 14/26 (53.8 %) patients, without a dilation of the upstream MPD (mean: 3.83 mm). Lesions showed hypointensity on T1-weighted images in all patients, and hyperintensity on T2-weighted images in 22/26 (84.6 %) patients. The affected parenchyma was hypovascular during the arterial phase in 25/26 (96.2 %) patients with contrast retention. MR-MRCP are effective techniques for the diagnosis of AIP showing the loss of the physiological lobulation and the typical contrastographic appearance. The presence of multiple, long stenoses without an upstream MPD dilation at MRCP suggests the diagnosis of AIP, and can be useful in differential diagnosis of pancreatic adenocarcinoma. (orig.)

Imaging patients with 'post-cholecystectomy syndrome': an algorithmic approach

International Nuclear Information System (INIS)

Terhaar, O.A.; Abbas, S.; Thornton, F.J.; Duke, D.; O'Kelly, P.; Abdullah, K.; Varghese, J.C.; Lee, M.J.

2005-01-01

AIM: To assess the role of ultrasound (US), magnetic resonance cholangiopancreatography (MRCP) and liver function tests (LFTs) in the evaluation of selected patients presenting with late post-cholecystectomy syndrome (PCS) who were referred for endoscopic retrograde cholangiopancreatography (ERCP) MATERIALS AND METHODS: In a retrospective study a final group of 42 patients with PCS referred for diagnostic ERCP underwent MRCP and abdominal US. ERCP and MRCP images were assessed for bile duct diameters and the presence of strictures and stones. A common bile duct (CBD) diameter of <10 mm was considered normal, whereas ≥10 mm was considered abnormal on US. Findings were correlated to LFTs with contingency table results performed for single techniques and combination of methods. RESULTS: In total 14 stones and one stricture were seen. US had a high negative predictive value (86.4%). MRCP had a sensitivity of 100% and specificity of 88.0%. ERCP is the most accurate test but failed in 11 patients, five of whom had a stone. The accuracy of US and LFTs increases to 93.8% if test results agree in either negative or positive outcome. CONCLUSION: US and LFTs are first-line tests in PCS. If the CBD on US is ≥10 mm, but no cause is identified, MRCP should be performed. If US and LFTs are normal then MRCP is not necessary. The availability of LFTs raises the diagnostic value of imaging

MR cholangio-pancreatography using an open, low magnetic field of 0.2 Tesla. Early clinical results and comparison with a higher magnetic field (1.5 Tesla) and with ERCP

International Nuclear Information System (INIS)

Wacker, Q.; Branding, G.; Wolf, K.J.; Zimmer, T.; Faiss, S.

1997-01-01

Aim: To evaluate MR cholangio-pancreatography (MRCP) using an open low magnetic field apparatus in normals and in patients with mechanical cholestasis. Methods: MRCP was performed on five normals and on 30 patients, using both an 0.2 Tesla and 1.5 Tesla apparatus. With the low field system, rapid acquisition by relaxation enhancement was used, for the high field system, half Fourier acquisition single shot turbo spin-echo sequences were used. In all patients, sonography and ERCP of PTC was performed; 23 underwent surgery. Results: In all normals it was possible to show the bile duct, hepatic duct, gall bladder and intrahepatic ducts of the first order. Using the high field system, second order ducts could be shown and sometimes third order ducts. In the patients, MRCP, using either system, demonstrated all 21 obstructive sites due to tumours or stenoses. Stones were shown in 69% by the low field system and in 88% by the high field system. Conclusion: MRCP can be successfully carried out using the low field system. In the presence of mechanical cholestasis, image quality is adequate for the localisation of stenoses and occlusions, and using an open magnet, is suitable for planning further intervention. (orig.) [de

Does Courvoisier's sign stand the test of time?

LENUS (Irish Health Repository)

Murphy, K

2012-11-01

To investigate the validity of Courvoisier\\'s sign, in the age of cross-sectional imaging and image analysis software by objectively measuring gallbladder volumes at magnetic resonance cholangiopancreatography (MRCP) in patients with and without biliary obstruction and to assess whether gallbladder volume is more significantly increased in patients with gallstone-related rather than non-gallstone-related biliary obstruction.

An increased flip angle in late phase Gd-EOB-DTPA MRI shows improved performance in bile duct visualization compared to T2w-MRCP

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Stelter, Lars, E-mail: lars.stelter@charite.de [Klinik für Radiologie, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Freyhardt, Patrick, E-mail: patrick.freyhardt@charite.de [Klinik für Radiologie, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Grieser, Christian, E-mail: christian.grieser@charite.de [Klinik für Radiologie, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Walter, Thula, E-mail: thula.walter@charite.de [Klinik für Radiologie, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Geisel, Dominik, E-mail: dominik.geisel@charite.de [Klinik für Radiologie, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Baur, Alexander, E-mail: alexander.baur@charite.de [Klinik für Radiologie, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); and others

2014-10-15

Highlights: • EOB-MRC acquired with a flip angle of 35° revealed a better diagnostic performance compared to T2w-MRCP. • EOB-MRC increased the readers’ confidence in identifying anatomic variations of the biliary tree. • As EOB-MRC comprises functional information it is a valuable adjunct to T2w-MRCP. - Abstract: Objectives: To estimate the additional value of an increased flip angle of 35° in late phase Gd-EOB-DTPA-enhanced magnetic resonance cholangiography, as compared to T2w-MRCP. Methods: 40 adult patients underwent Gd-EOB-DTPA enhanced MRI of the liver including a T2-weighted 3D TSE MRCP (T2w-MRCP) as well as a late phase T1-weighted THRIVE sequences applying a flip angle of 35° (fa35). Two experienced observers evaluated the images regarding the delineation of the different biliary regions using a three-point grading system. A five-point scale was applied to determine the readers’ confidence in identifying anatomical variations of the biliary tree. ROI analysis was performed to compare the signal-to-noise (SNR) and contrast-to-noise (CNR) ratios. Results: The quality for visualizing the biliary tree differed between T2w-MRCP and fa35 (p = <0.001). Late phase EOB-MRC was rated as good for delineating the entire biliary system, whereas T2w-MRCP received an overall poor rating. Especially the depiction of the intrahepatic bile ducts was estimated as problematic in T2w-MRCP. T2w-MRCP and fa35 revealed a discordant assessment of anatomical variations in 12.5% of the cases, comprising a generally higher confidence level for fa35 (4.0 ± 1.1 vs. 2.2 ± 1.2, p = <0.001). SNR proofed to be significantly higher in fa35 (p = <0.001), whereas T2w-MRCP revealed a significantly higher CNR (<0.001). Conclusions: Gd-EOB-DTPA enhanced magnetic resonance cholangiography acquired with a flip angle of 35° revealed a better diagnostic performance compared to T2w-MRCP and might be a valuable adjunct in assessing functional bile duct abnormalities.

Ansa Pancreatica: A Case Report of a Type of Ductal Variation in a Patient with Idiopathic Acute Recurrent Pancreatitis

International Nuclear Information System (INIS)

Kim, Hye Mi; Park, Jung Yup; Kim, Myeong Jin

2010-01-01

Ansa pancreatica is a rare type of pancreatic ductal variation. Recently, ansa pancreatic has been considered as a predisposing factor in patients with idiopathic acute pancreatitis. To the best of our knowledge, no previously published report in Korea has described ansa pancreatica. We report a case of acute recurrent pancreatitis with ansa pancreatica, which was revealed on magnetic resonance cholangiopancreatography (MRCP)

Quality rating of MR-cholangiopancreatography with oral application of iron oxide particles

International Nuclear Information System (INIS)

Lorenzen, M.; Wedegaertner, U.; Fiehler, J.; Adam, G.

2003-01-01

Purpose: To compare image quality in magnetic resonance cholangiopancreatography (MRCP) performed with and without oral application of Loesferron trademark (ferrous gluconate, Lilly Pharma, Hamburg). Materials and Methods: A prospective study compares MRCPs performed on 52 patients with a 1.5 T clinical whole body scanner using a standard body coil. After randomization, patients ingested either 0.5 l of Loeseferron trademark (n=27, group 1) or no oral contrast agent (n=25, group 2) prior to the examination. 7 RARE (40 to 20 ) sequences were obtained, followed by selected 3 mm HASTE (T 2 -weighted with fat suppression) sequences. After blinding, image quality was rated by two radiologists using a scale of 1 (not discernible) to 5 (very well discernible). The following sections of the biliary ductal system were evaluated: left and right hepatic duct, extrahepatic bile duct and intrapancreatic bile duct. The pancreatic duct was evaluated by its location: head, body and tail of the pancreas. A Wilcoxon-Mann-Whitney test was used to determine significant differences (p trademark was well tolerated by all patients, and all sequences could be acquired and evaluated in all 52 patients. For the different sections of the biliary system, the mean ratings with and without Loesferron trademark were, respectively, 3.28 and 3.36 for the left hepatic duct, 3.26 and 3.33 for the right hepatic duct, 3.46 and 4.0 for the extrahepatic bile duct, and 2.8 and 3.48 for the intrapancreatic bile duct. The corresponding ratings for the pancreatic duct were 2.8 and 3.24 for the pancreatic head, 2.84 and 3.38 for the pancreatic body, and 2.68 and 3.22 for the pancreatic tail. The differences with and without contrast agent were not statistically significant. Interobserver variability was between 0.37 for the pancreatic duct in the tail of the pancreas and 0.66 for the right hepatic duct. Conclusion: Despite the trend toward a better rating of the image quality for all sections of the

MRCP in the evaluation of pancreaticobiliary disease in children

International Nuclear Information System (INIS)

Arcement, C.M.; Meza, M.P.; Arumanla, S.; Towbin, R.B.

2001-01-01

Background. Radiologic assessment of pancreaticobiliary ductal disease (PBDD) in children currently consists of physiologic tests (radionuclide examinations) or invasive anatomic studies (ERCP and PTC). An accurate noninvasive and reproducible examination that can direct the subsequent need for more invasive studies would be helpful in this patient group. Objective. To determine the effectiveness of MRCP as a screening tool for PBBD in the pediatric population. Materials and methods. Over the last year, 33 patients ranging from 7 months to 20 years of age were prospectively evaluated with MRCP on a 1.5 T magnet. One patient was examined twice, several months apart. Thirteen patients had liver transplants. Coronal SPGR and heavily T-2W FSE cross-sectional images were obtained. Standard and oblique 2- to 6-cm-thick slab SSFSE (single-shot fast spin echo) acquisition and 3D MIP reconstruction of 2D FSE images were obtained in the planes of the CBD and pancreatic duct. Nine studies were performed with the patient under sedation with chloral hydrate or nembutal and fentanyl with quiet respiration, and the non-sedated patients were assessed with single breath hold or quiet respiration. Three patients received secretin. MRCP results were correlated with ERCP (9), PTC (7), liver biopsy (13), clinical information (6), surgery (3), and autopsy (2). Results. All 34 studies performed were considered diagnostic. Periportal fluid, proximal bowel fluid, and gallbladder distention did not significantly diminish the diagnostic information in any cases. Motion artifact did not cause serious degradation in image quality. MRCP depicted abnormalities including stones, stricture, intraductal tumor, and extrinsic compression, all of which were confirmed at ERCP, PTC (two unsuccessful in patients with non-dilated ducts by MRCP), surgery, liver biopsy, and autopsy. There were no false-negative examinations. Normal pancreatic studies performed to exclude pancreas divisum were followed

MRCP in the evaluation of pancreaticobiliary disease in children

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Arcement, C.M.; Meza, M.P.; Arumanla, S.; Towbin, R.B. [Children' s Hospital of Pittsburgh, Dept. of Radiology, Pittsburgh, PA (United States)

2001-02-01

Background. Radiologic assessment of pancreaticobiliary ductal disease (PBDD) in children currently consists of physiologic tests (radionuclide examinations) or invasive anatomic studies (ERCP and PTC). An accurate noninvasive and reproducible examination that can direct the subsequent need for more invasive studies would be helpful in this patient group. Objective. To determine the effectiveness of MRCP as a screening tool for PBBD in the pediatric population. Materials and methods. Over the last year, 33 patients ranging from 7 months to 20 years of age were prospectively evaluated with MRCP on a 1.5 T magnet. One patient was examined twice, several months apart. Thirteen patients had liver transplants. Coronal SPGR and heavily T-2W FSE cross-sectional images were obtained. Standard and oblique 2- to 6-cm-thick slab SSFSE (single-shot fast spin echo) acquisition and 3D MIP reconstruction of 2D FSE images were obtained in the planes of the CBD and pancreatic duct. Nine studies were performed with the patient under sedation with chloral hydrate or nembutal and fentanyl with quiet respiration, and the non-sedated patients were assessed with single breath hold or quiet respiration. Three patients received secretin. MRCP results were correlated with ERCP (9), PTC (7), liver biopsy (13), clinical information (6), surgery (3), and autopsy (2). Results. All 34 studies performed were considered diagnostic. Periportal fluid, proximal bowel fluid, and gallbladder distention did not significantly diminish the diagnostic information in any cases. Motion artifact did not cause serious degradation in image quality. MRCP depicted abnormalities including stones, stricture, intraductal tumor, and extrinsic compression, all of which were confirmed at ERCP, PTC (two unsuccessful in patients with non-dilated ducts by MRCP), surgery, liver biopsy, and autopsy. There were no false-negative examinations. Normal pancreatic studies performed to exclude pancreas divisum were followed

Added value of gadoxetic acid-enhanced T1-weighted magnetic resonance cholangiography for the diagnosis of post-transplant biliary complications

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Kinner, Sonja [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Schubert, Tilman B. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); Basel University Hospital, Clinic of Radiology and Nuclear Medicine, Basel (Switzerland); Said, Adnan [University of Wisconsin-Madison, Department of Medicine, Madison, WI (United States); Mezrich, Joshua D. [University of Wisconsin-Madison, Department of Surgery, Madison, WI (United States); Reeder, Scott B. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); University of Wisconsin-Madison, Department of Medicine, Madison, WI (United States); University of Wisconsin-Madison, Department of Biomedical Engineering, Madison, WI (United States); University of Wisconsin-Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin-Madison, Department of Emergency Medicine, Madison, WI (United States)

2017-10-15

Biliary complications after liver transplantation (LT) are common. This study aimed to ascertain the value of gadoxetic acid-enhanced T1-weighted (T1w) magnetic resonance cholangiography (MRC) to evaluate anastomotic strictures (AS), non-anastomotic strictures (NAS) and biliary casts (BC). Sixty liver-transplanted patients with suspicion of biliary complications and T2w-MRCP and T1w-MRC followed by endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC) were analysed. Two readers reviewed the MRCs and rated image quality (IQ) and likelihood for AS/NAS/BC on Likert scales. Sensitivity, specificity and predictive values were calculated, ROC curve analysis performed, and inter-reader variability assessed. The subjective added value of T1w-MRC was rated. IQ was high for all sequences without significant differences (2.83-2.88). In 39 patients ERCP/PTC detected a complication. Sensitivity and specificity for AS were 64-96 using T2w-MRCP, increasing to 79-100 using all sequences. Use of all sequences increased the sensitivity of detecting NAS/BC from 72-92% to 88-100% and 67-89% to 72-94%, respectively. Kappa values were substantial (0.45-0.62). T1w-MRC was found to be helpful in 75-83.3%. Combining T1w-MRC and T2w-MRCP increased sensitivity and specificity and diagnostic confidence in patients after LT with suspected biliary complications. T1w-MRC is a valuable tool for evaluating post-transplant biliary complications. (orig.)

Usefulness of MR cholangiopancreatography after intravenous morphine administration

International Nuclear Information System (INIS)

Lee, So Jung; Ko, Ji Ho; Cho, Young Duk; Jung, Mi Hee; Yoon, Byung Chull

2007-01-01

We wanted to assess the usefulness of MRCP after intravenous morphine administration in the evaluation of the hepatopancreatic pancreatico-biliary ductal system. We studied 15 patients who were suspected of having disease of hepatopancreatic ductal system and they did not have any obstructive lesion on ultrasonography and/or CT. MRCP was acquired before and after morphine administration (0.04 mg/kg, intravenously). Three radiologists scored the quality of the images of the anatomic structures in the hepatopancreatic ductal system. We directly compared the quality of the images obtained with using the two methods and the improvement of the artifacts by pulsatile vascular compression. The MRCP images obtained after intravenous morphine administration were better than those obtained before morphine administration for visualizing the hepatopancreatic ductal system. On direct comparison, the MRCP images obtained after morphine administration were better in 12 cases, equivocal in two cases, and the images before morphine administration were better in only one case. In three patients, MRCP before morphine injection showed signal loss at the duct across the pulsatile hepatic artery. In two of three patients, MRCP after morphine injection showed no signal loss in this ductal area. MRCP after intravenous morphine administration enables physicians to see the hepatopancreatic ductal system significantly better and the artifacts caused by pulsation of the hepatic artery can be avoided

Vergleich von 2D- und 3D-Sequenzen für die MRCP. Klinischer Stellenwert der einzelnen Techniken

NARCIS (Netherlands)

Wallnoefer, A. M.; Herrmann, K. A.; Beuers, U.; Zech, C. J.; Gourtsoyianni, S.; Reiser, M. F.; Schoenberg, S. O.

2005-01-01

Magnetic resonance cholangio-pancreaticograpy (MRCP) is a non-invasive imaging modality of the pancreatico-biliary system which plays an increasingly important role in the clinical and diagnostic workup of patients with biliary or pancreatic diseases. The present review is designed to give an

Comparison of 2D and 3D sequences for MRCP. Clinical value of the different techniques; Vergleich von 2D- und 3D-Sequenzen fuer die MRCP. Klinischer Stellenwert der einzelnen Techniken

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Wallnoefer, A.M.; Herrmann, K.A.; Zech, C.J.; Gourtsoyianni, S.; Reiser, M.F.; Schoenberg, S.O. [Klinikum Grosshadern der Ludwig-Maximilian-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Beuers, U. [Klinikum Grosshadern der Ludwig-Maximilian-Universitaet Muenchen (Germany). Klinik fuer Innere Medizin II

2005-11-01

Magnetic resonance cholangio-pancreaticograpy (MRCP) is a non-invasive imaging modality of the pancreatico-biliary system which plays an increasingly important role in the clinical and diagnostic workup of patients with biliary or pancreatic diseases. The present review is designed to give an overview of the currently available and appropriate sequences, their technical background, as well as new developments and their relevance to the various clinical issues and challenges. The impact of the latest technical innovations, such as integrated parallel imaging techniques and navigator-based respiratory triggering, on the diagnostic capacities of MRCP is discussed. In this context, the individual value of RARE, T2w single shot turbo/fast spin echo (SSFSE) and the recently introduced 3D T2w turbo/fast spin echo sequences (T2w 3D-T/FSE) is reviewed. RARE imaging may be preferred in severely ill patients with limitations in cooperation, SSFSE is particularly effective in differentiating benign and malignant stenosis, and 3D-FSE offers additional advantages in the detection of small biliary concrements. (orig.) [German] Die Magnetresonanzcholangiopankreatikographie (MRCP) ist eine nichtinvasive Untersuchungsmethode des pankreatikobiliaeren Systems, die heute einen festen Platz in der klinischen Diagnostik eingenommen hat. Die vorliegende Arbeit gibt einen Ueberblick ueber die derzeit gaengigen Sequenzen, ihre technischen Grundlagen sowie ihre jeweilige Bedeutung in den verschiedenen klinischen Einsatzgebieten und Fragestellungen. Darueber hinaus werden die Bedeutung der parallelen Bildgebung, der navigatorbasierten Atemtriggerung und der neu eingefuehrten dreidimensionalen Sequenzen fuer die MRCP sowie ihre moeglichen Einsatzgebiete behandelt. Fuer die MRCP haben die 3 gaengigen Sequenzen, die SS-RARE-Sequenz, die T2w-single-shot-fast-spin-echo- (SSFSE) und die 3D-FSE-Sequenz spezifische Vor- und Nachteile. Die SS-RARE-Sequenz ist aufgrund der sehr kurzen Messzeit bei

Massive pleural effusion in a young woman

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Ghiringhelli, Paolo; Cattaneo, Roberto; Tiso, Angelo; Cesaro, Claudia

2012-01-01

Pleural effusion is a clinical manifestation shared by several underlying pathologies. The differential diagnosis is based on the clinical history, the physical examination, the analysis of the pleural fluid, and the laboratory data (mainly blood tests). There are cases, such as the patient described, where TC is not enough, and unusual imaging techniques are required for the study of pleural effusion, i.e. magnetic resonance cholangiography, cholangiopancreatography (MRCP) and endoscopic ret...

Evaluation of dynamic MRCP after secretin stimulation for biliopancreatic diseases

International Nuclear Information System (INIS)

Ohhigashi, Seiji; Nishio, Takeki; Watanabe, Fumihiko; Haradome, Hiroki; Doi, Osamu

2000-01-01

Both pancreaticobiliary maljunction and pancreatogastrostomy after pancreatoduodenectomy were analyzed to assess the utility of dynamic MRCP after secretin stimulation. Dynamic MRCP obtained every 60 seconds for 15 minutes after secretin administration revealed the bile and pancreatic fluid kinetics. Calculating the intensity value from the MR images allowed objective estimation of the bile and pancreatic fluid kinetics. Thus, this study demonstrated that dynamic MRCP after secretin stimulation was significantly useful in evaluating not only the morphologic features in pancreaticobiliary maljunction but also pancreatic exocrine function after resection of the pancreas. (author)

Papel da ranitidina como meio de aprimorar a qualidade do exame de colangiopancreatografia por ressonância magnética The role of ranitidine in the enhancement of imaging quality in magnetic resonance cholangiopancreatography

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Lucas Rios Torres

2013-04-01

Full Text Available OBJETIVO: Avaliar o impacto da ranitidina por via oral na qualidade do exame de colangiopancreatografia por ressonância magnética (CPRM. MATERIAIS E MÉTODOS: Trinta e dois pacientes realizaram CPRM com aquisições 3D e 2D, com três estratégias de supressão do sinal líquido gastrintestinal: a apenas em jejum; b 12 horas após ingerir 300 mg de ranitidina; c após a ingestão de solução de gadolínio. Três observadores avaliaram os estudos, atentos para o grau de visualização da árvore biliopancreática. Foi medida a concordância interobservador com o teste kappa. A diferença entre técnicas e formas de aquisição foi avaliada pela média da soma dos escores de graduação. RESULTADOS: As três estratégias de supressão do sinal líquido gastrintestinal apresentaram elevada reprodutibilidade. A supressão do sinal líquido gastrintestinal com a ranitidina foi semelhante ao jejum e ambas foram piores do que a solução de gadolínio. As aquisições 3D superaram a 2D apenas na visualização do ducto cístico e da vesícula biliar, sendo inferior ou equivalente nos demais segmentos ductais biliopancreáticos. CONCLUSÃO: O uso da ranitidina não parece justificado para aprimorar a avaliação da árvore biliopancreática em exames de CPRM. A CPRM 2D apenas em jejum permite a visualização ductal com elevada qualidade e reprodutibilidade na maioria dos casos.OBJECTIVE: To assess the impact of oral ranitidine on the imaging quality in magnetic resonance cholangiopancreatography (MRCP. MATERIALS AND METHODS: Thirty-two patients underwent MRCP with 3D and 2D acquisitions, and three strategies for suppression of the gastrointestinal fluid signal: a only at fasting; b 12 hours after ingestion of 300 mg ranitidine; c after oral administration of gadolinium solution. Three observers reviewed the images with a focus on the degree of visualization of the biliopancreatic tree. The interobserver agreement was evaluated with the kappa test

Hilar cholangiocarcinoma: Cross sectional evaluation of disease spectrum

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Mahajan, Mangal S; Moorthy, Srikanth; Karumathil, Sreekumar P; Rajeshkannan, R; Pothera, Ramchandran

2015-01-01

Although hilar cholangiocarcinoma is relatively rare, it can be diagnosed on imaging by identifying its typical pattern. In most cases, the tumor appears to be centered on the right or left hepatic duct with involvement of the ipsilateral portal vein, atrophy of hepatic lobe on that side, and invasion of adjacent liver parenchyma. Multi-detector computed tomography (MDCT) and magnetic resonance cholangiopancreatography (MRCP) are commonly used imaging modalities to assess the longitudinal and horizontal spread of tumor. PMID:25969643

The role of MRI in evaluation of acute pancreatitis

International Nuclear Information System (INIS)

Baba, Maiko; Munechika, Horotsugu

2003-01-01

The purpose of this study is to assess the role of MRI in acute pancreatitis. The findings of MPD (main pancreatic duct) and CBD (common bile duct) on MR cholangiopancreatography (MRCP) images were retrospectively reviewed in 60 patients with acute pancreatitis. The patients were divided into two groups; severe and mild pancreatitis, according to the criteria of Japanese group of investigation for pancreatic diseases. T2 weighed MR images were compared with contrast-enhanced CT images for evaluation of severity of the disease. MRCP images were also compared with endoscopic retrograde cholangiopancreatography (ERCP) images for evaluation of MPD and CBD. CBD was more clearly demonstrated by MRCP than MPD. Both MPD and CBD were more clearly seen in the mild group than in the severe group. A few false-negative cases were seen in MRCP. T2 weighed MR images were almost the same as contrast-enhanced CT images in diagnosis of acute pancreatitis. MRCP is useful for evaluation of CBD in severe cases and for evaluation of both CBD and MPD in mild cases of acute pancreatitis. The severity of disease can be evaluated by combination of T2 weighted MR images and MRCP alternative to contrast-enhanced CT. (author)

Medical image of the week: ascending cholangitis from biliary obstruction

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Wong C

2013-04-01

Full Text Available A 79 year old man with a history of quadriplegia presented to an outside hospital in septic shock. He was found to have an elevated total bilirubin of 10 mg/dL, direct bilirubin of 7 mg/dL, alkaline phosphatase of 405 U/L, and lipase of 370 U/L. Imaging showed cholelithiasis with likely intra- and extrahepatic biliary duct dilatation. The patient underwent placement of a biliary drain with clinical improvement. Additional imaging was requested prior to endoscopic retrograde cholangiopancreatography (ERCP, but magnetic resonance cholangiopancreatography (MRCP was unavailable due to metallic implants. Interventional radiology performed a cholangiogram using the biliary drain which confirmed biliary obstruction. ERCP was then performed, with significant biliary sludge found and two stents placed.

Secretin-stimulated MR cholangio-pancreatography in the evaluation of asymptomatic patients with non-specific pancreatic hyperenzymemia

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Donati, Francescamaria, E-mail: fra.donati@katamail.co [2nd Department of Radiology, Pisa University-Hospital, Via Paradisa 2, I-56124 Pisa (Italy); Boraschi, Piero; Gigoni, Roberto; Salemi, Simonetta [2nd Department of Radiology, Pisa University-Hospital, Via Paradisa 2, I-56124 Pisa (Italy); Faggioni, Lorenzo; Bertucci, Cristina; Cecchi, Claudia; Bartolozzi, Carlo [Diagnostic and Interventional Radiology, University of Pisa, Via Rome 67, I-56126 Pisa (Italy); Falaschi, Fabio [2nd Department of Radiology, Pisa University-Hospital, Via Paradisa 2, I-56124 Pisa (Italy)

2010-08-15

Purpose: To assess the diagnostic value of secretin-stimulated MRCP (SS-MRCP) compared with conventional MRCP in asymptomatic patients with mild elevations of pancreatic enzymes. Materials and methods: Eighty asymptomatic patients with pancreatic hyperenzymemia underwent MR imaging at 1.5 T-device (Signa EXCITE, GE Healthcare). After the acquisition of axial T1w,T2w sequences, and conventional MRCP, SS-MRCP was performed using a single-slice coronal breath-hold, thick-slab, SSFSE T2w sequence, repeated every 30 s up to 15 min following intravenous injection of secretin (Secrelux, Sanochemia). Results: On the basis of the standards of reference, our final diagnoses were: negative findings (n = 23), pancreas divisum (n = 22), mild chronic pancreatitis (n = 14), inflammatory ampullary stenosis (n = 3), juxtapapillary duodenal diverticulum (n = 1), small cystic lesions (<1 cm) (n = 22; 5/22 cases associated with pancreas divisum). The image quality of SS-MRCP was significantly higher than that of conventional MRCP (p < 0.0001). Standards of reference did not differ significantly from of SS-MRCP findings (p = 0.5), while was statistically different from those of conventional MRCP (p < 0.0001). A significant difference was found between conventional MRCP and SS-MRCP findings (p < 0.0001). Conclusion: In asymptomatic patients with non-specific pancreatic hyperenzymemia SS-MRCP may represent the best non-invasive diagnostic technique, since it gives morphological and functional information.

Evaluation of date syrup as an oral negative contrast agent for MRCP.

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Govindarajan, Arunkumar; Lakshmanan, Prakash Manikka; Sarawagi, Radha; Prabhakaran, Velu

2014-11-01

The purpose of this study was to compare the in vitro effects of date syrup with those of other contrast agents by qualitative and quantitative analysis and in vivo evaluation of the use of date syrup to improve the quality of MRCP images. Phantoms containing date syrup, ferumoxsil, pineapple juice, and water were imaged by 1.5-T MRI with T2-weighted and MRCP sequences, and signal-to-noise ratios were calculated. Biochemical analysis of date syrup was performed to find the nature of iron in it, and the iron content was quantified by energy-dispersive x-ray spectroscopy. Sixty patients underwent MRCP before and 30 minutes after ingestion of 100 mL of date syrup. Unenhanced and contrast-enhanced images were scored for gastrointestinal tract signal suppression and visualization of various pancreaticobiliary structures. In vitro evaluation showed that images obtained with date syrup had a signal-to-noise ratio comparable to that of images obtained with ferumoxsil in T2-weighted and MRCP sequences. The iron concentration in date syrup was 2.6 mg/dL, and it was in ferric form. Images obtained after oral contrast administration had statistically significant improvement in gastrointestinal tract signal suppression (p Date syrup can be used as a negative oral contrast agent for gastrointestinal tract signal suppression during MRCP and for improving visualization of various pancreaticobiliary structures.

The diagnostic value of MRI and MRCP in congenital duct cysts and complications

International Nuclear Information System (INIS)

Xiao Fang; Huang Suiqiao; Hu Tao

2009-01-01

Objective: To investigate the value of MRI and MRCP in diagnosis of congenital duct cysts and their complications. Methods: The MRI and MRCP of 29 cases of congenital duct cyst verified by pathological findings were analyzed retrospectively. Results: In 29 cases of Congenital choledochocele, 10 of which are type lb and 7 were Ic, appearing as the focal choledochal ecstasis, which were connected with the bile duct tree and displayed by MRCP. 10 cases were type IV and 2 are type V, appearing as the multiple cholangiectasis extrahepaticly and/or intrahepaticly and displayed by MRCP as the multiple cystoid with different sizes. There were 7 cases with complication of calculus, 4 in type Ib and 3 in type IV, appearing as single or multiple non-enhanced lesion with clear border. There were 3 cases with complication of tumors, 1 cholangiocarcinoma in type IV and type V respectively, appearing as the enhanced nodus within the wall of dilatant bile duct, 1 gallbladder carcinoma in type lb with multiple liver metastasis. The interruption of distal choledochocele was demonstrated in the complication of biliary atresia in 1 of type V. There was pancreatitis in 1 of type IV. The diagnosis and typing of choledochocele can be accurately made by MRI combined with MRCP, and complications were easily and clearly showed. The accuracy rate for location of choledochocele was 100%. Conclusion: There is an important value for MRI and MRCP examination in diagnosis of congenital bile duct cysts and their complications. (authors)

[Comparison of 2D and 3D sequences for MRCP. Clinical value of the different techniques].

Science.gov (United States)

Wallnoefer, A M; Herrmann, K A; Beuers, U; Zech, C J; Gourtsoyianni, S; Reiser, M F; Schoenberg, S O

2005-11-01

Magnetic resonance cholangio-pancreaticograpy (MRCP) is a non-invasive imaging modality of the pancreatico-biliary system which plays an increasingly important role in the clinical and diagnostic workup of patients with biliary or pancreatic diseases. The present review is designed to give an overview of the currently available and appropriate sequences, their technical background, as well as new developments and their relevance to the various clinical issues and challenges. The impact of the latest technical innovations, such as integrated parallel imaging techniques and navigator-based respiratory triggering, on the diagnostic capacities of MRCP is discussed. In this context, the individual value of RARE, T2w single shot turbo/fast spin echo (SSFSE) and the recently introduced 3D T2w turbo/fast spin echo sequences (T2w 3D-T/FSE) is reviewed. RARE imaging may be preferred in severely ill patients with limitations in cooperation, SSFSE is particularly effective in differentiating benign and malignant stenosis, and 3D-FSE offers additional advantages in the detection of small biliary concrements.

Endoscopic Sphincterotomy Using the Rendezvous Technique for Choledocholithiasis during Laparoscopic Cholecystectomy: A Case Report.

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Tanaka, Takayuki; Haraguchi, Masashi; Tokai, Hirotaka; Ito, Shinichiro; Kitajima, Masachika; Ohno, Tsuyoshi; Onizuka, Shinya; Inoue, Keiji; Motoyoshi, Yasuhide; Kuroki, Tamotsu; Kanemastu, Takashi; Eguchi, Susumu

2014-05-01

A 50-year-old male was examined at another hospital for fever, general fatigue and slight abdominal pain. He was treated with antibiotics and observed. However, his symptoms did not lessen, and laboratory tests revealed liver dysfunction, jaundice and an increased inflammatory response. He was then admitted to our hospital and underwent an abdominal computed tomography scan and magnetic resonance cholangiopancreatography (MRCP), which revealed common bile duct (CBD) stones. He was diagnosed with mild acute cholangitis. As the same time, he was admitted to our hospital and an emergency endoscopic retrograde cholangiopancreatography was performed. Vater papilla opening in the third portion of the duodenum and presence of a peripapillary duodenal diverticulum made it difficult to perform cannulation of the CBD. In addition, MRCP revealed that the CBD was extremely narrow (diameter 5 mm). We therefore performed laparoscopic cholecystectomy and endoscopic sphincterotomy using the rendezvous technique for choledocholithiasis simultaneously rather than laparoscopic CBD exploration. After the operation, the patient was discharged with no complications. Although the rendezvous technique has not been very commonly used because several experts in the technique and a large operating room are required, this technique is a very attractive and effective approach for treating choledocholithiasis, for which endoscopic treatment is difficult.

Endoscopic Sphincterotomy Using the Rendezvous Technique for Choledocholithiasis during Laparoscopic Cholecystectomy: A Case Report

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Takayuki Tanaka

2014-08-01

Full Text Available A 50-year-old male was examined at another hospital for fever, general fatigue and slight abdominal pain. He was treated with antibiotics and observed. However, his symptoms did not lessen, and laboratory tests revealed liver dysfunction, jaundice and an increased inflammatory response. He was then admitted to our hospital and underwent an abdominal computed tomography scan and magnetic resonance cholangiopancreatography (MRCP, which revealed common bile duct (CBD stones. He was diagnosed with mild acute cholangitis. As the same time, he was admitted to our hospital and an emergency endoscopic retrograde cholangiopancreatography was performed. Vater papilla opening in the third portion of the duodenum and presence of a peripapillary duodenal diverticulum made it difficult to perform cannulation of the CBD. In addition, MRCP revealed that the CBD was extremely narrow (diameter 5 mm. We therefore performed laparoscopic cholecystectomy and endoscopic sphincterotomy using the rendezvous technique for choledocholithiasis simultaneously rather than laparoscopic CBD exploration. After the operation, the patient was discharged with no complications. Although the rendezvous technique has not been very commonly used because several experts in the technique and a large operating room are required, this technique is a very attractive and effective approach for treating choledocholithiasis, for which endoscopic treatment is difficult.

The value of cholangiography through Jackson-Pratt drains in the management of postoperative biliary injuries.

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Macedo, Francisco Igor B; Casillas, Victor J; Davis, James S; Levi, Joe U; Sleeman, Danny

2014-01-01

Iatrogenic biliary injury is the most significant complication after laparoscopic cholecystectomy. We present our experience with an alternative diagnostic approach using transcatheter cholangiography (TCC) through a Jackson-Pratt (JP) drain and discuss potential benefits and limitations of the technique. From March 2002 to February 2012, 40 patients with major postoperative biliary injury underwent biliary reconstruction at our institution. Mean age was 51.7 ± 18.1 years (range, 19 to 86 years) with 30 (75%) females. Seventeen (42.5%) injuries were detected intraoperatively and in 13 (32.5%) cases, JP drains were placed for biliary drainage. Lesions were classified according to Bismuth grade: I (10 patients [25%]), II (10 patients [25%]), III (six patients [15%]), IV (10 patients [25%]), and V (four patients [10%]). TCC was performed in seven patients with JP drains (53.8%). It fully defined the injury site in three cases of limited magnetic resonance cholangiopancreatography (MRCP) such as common hepatic duct and common bile duct leaks and in four cases (57.1%) that endoscopic retrograde cholangiopancreatography (ERCP) was limited as a result of clipping of the distal common bile duct. TCC showed promising results in cases of limited MRCP and ERCP such as fistulous orifices or leakage. It may represent an alternative adjunct in the diagnostic armamentarium of complex biliary injuries.

The use of endoscopic ultrasonography in the diagnosis of the causes of common bile duct dilation

International Nuclear Information System (INIS)

Sajewicz, Z.; Wozniak-Stolarska, B.; Salomon, A.; Poniewierka, E.; Kempinski, R.

2006-01-01

Background. Ultrasonography (US) does not come up to the expectations in the diagnosis of the causes of common bile duct (CBD) dilation. Objectives. An assessment of the usefulness of endoscopic ultrasonography (EUS) in the diagnosis of the causes of CBD dilation. Material and Methods. The authors examined 30 persons (16 females and 14 males) with CBD dilated > 7 mm in US. In these patients the authors performed EUS with the usage of Pentax FG-38UX echoendoscope of 5-10 MHz frequency connected with EUB 6000 Hitachi ultrasonograph looking for the cause of CBD dilation. Findings gathered were verified with the usage of endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP). Results. In 16 patients the authors found stones in CBD. In ERCP or MRCP the frequency of CBD stones was a bit higher. In these examinations CBD stones were found in 18 patients. The authors found out that pancreatic head carcinoma was the cause of CBD dilation in 8 patients; in 2 patients the authors diagnosed ampullary carcinoma and in 1 patient - carcinoma of distal part of CBD. In 1 patient the authors pointed out a benign stricture of CBD with dilation above the stricture. Conclusions. EUS is a useful diagnosing method of the causes of CBD dilation. (authors)

Incremental value of secretin-enhanced magnetic resonance cholangiopancreatography in detecting ductal communication in a population with high prevalence of small pancreatic cysts

International Nuclear Information System (INIS)

Rastegar, Neda; Matteoni-Athayde, Luciana G.; Eng, John; Takahashi, Naoki; Tamm, Eric P.; Mortele, Koenraad J.; Syngal, Sapna; Margolis, Daniel; Lennon, Anne Marie; Wolfgang, Christopher L.; Fishman, Elliot K.; Hruban, Ralph H.; Goggins, Michael; Canto, Marcia I.; Kamel, Ihab R.

2015-01-01

Highlights: •Secretin improved visualization of ductal communication of a cystic pancreatic lesion. •No association between cysts and gender, ethnicity or type of high risk. •Incremental value of secretin could offset the added cost and time. -- Abstract: Purpose: We investigated the incremental diagnostic yield of S-MRCP in a population with high prevalence of small pancreatic cysts. Methods: Standard MRCP protocol was performed with and without secretin using 1.5 T units in subjects undergoing pancreatic screening because of a strong family history of pancreatic cancer as part of the multicenter Cancer of the Pancreas Screening-3 trial (CAPS 3). All studies were reviewed prospectively by two independent readers who recorded the presence and number of pancreatic cysts, the presence of visualized ductal communication before and after secretin, and the degree of confidence in the diagnoses. Result: Of 202 individuals enrolled (mean age 56 years, 46% males), 93 (46%) had pancreatic cysts detected by MRCP, and 64 of the 93 had pre-and post-secretin MRCP images available for comparison. Data from the 128 readings show that 6 (6/128 = 4.7%) had ductal communication visualized only on the secretin studies compared to pre-secretin studies (odds ratio 1.28, p = 0.04). In addition, there was a statistically significant increase in confidence in reporting ductal communication after secretin compared to before secretin (p < 0.0005). Conclusion: At 1.5 T MRI, the use of secretin can improve the visualization of ductal communication of cystic pancreatic lesions

Incremental value of secretin-enhanced magnetic resonance cholangiopancreatography in detecting ductal communication in a population with high prevalence of small pancreatic cysts

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Rastegar, Neda; Matteoni-Athayde, Luciana G.; Eng, John [Departments of Medicine (Gastroenterology) and Radiology, The Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins Medical Institutions (United States); Takahashi, Naoki [Mayo Clinic (United States); Tamm, Eric P. [MD Anderson Cancer Center (United States); Mortele, Koenraad J. [Beth Israel Deaconess Medical Center (United States); Syngal, Sapna [Dana Farber Cancer Institute (United States); Margolis, Daniel [University of California, Los Angeles (United States); Lennon, Anne Marie; Wolfgang, Christopher L.; Fishman, Elliot K.; Hruban, Ralph H.; Goggins, Michael; Canto, Marcia I. [Departments of Medicine (Gastroenterology) and Radiology, The Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins Medical Institutions (United States); Kamel, Ihab R., E-mail: ikamel@jhmi.edu [Departments of Medicine (Gastroenterology) and Radiology, The Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins Medical Institutions (United States)

2015-04-15

Highlights: •Secretin improved visualization of ductal communication of a cystic pancreatic lesion. •No association between cysts and gender, ethnicity or type of high risk. •Incremental value of secretin could offset the added cost and time. -- Abstract: Purpose: We investigated the incremental diagnostic yield of S-MRCP in a population with high prevalence of small pancreatic cysts. Methods: Standard MRCP protocol was performed with and without secretin using 1.5 T units in subjects undergoing pancreatic screening because of a strong family history of pancreatic cancer as part of the multicenter Cancer of the Pancreas Screening-3 trial (CAPS 3). All studies were reviewed prospectively by two independent readers who recorded the presence and number of pancreatic cysts, the presence of visualized ductal communication before and after secretin, and the degree of confidence in the diagnoses. Result: Of 202 individuals enrolled (mean age 56 years, 46% males), 93 (46%) had pancreatic cysts detected by MRCP, and 64 of the 93 had pre-and post-secretin MRCP images available for comparison. Data from the 128 readings show that 6 (6/128 = 4.7%) had ductal communication visualized only on the secretin studies compared to pre-secretin studies (odds ratio 1.28, p = 0.04). In addition, there was a statistically significant increase in confidence in reporting ductal communication after secretin compared to before secretin (p < 0.0005). Conclusion: At 1.5 T MRI, the use of secretin can improve the visualization of ductal communication of cystic pancreatic lesions.

Magnetic resonance cholangiographic (MRCP) features of ischemic-type biliary lesions (ITBL). A case-control study

International Nuclear Information System (INIS)

Collettini, F.; Kroencke, T.J.; Renz, D.M.; Bucourt, M. de; Poellinger, A.; Heidenhain, C.; Neuhaus, P.

2011-01-01

Purpose: To evaluate the spectrum of MR cholangiography (MRCP) features of ischemic-type biliary lesions (ITBL) after orthotopic liver transplantation (OLT). Materials and Methods: 30 patients (16 m, 14 f) with an average age of 52 years (9 - 69 y) were examined in two 1.5 MR units using breath-hold 2D-SS-FSE-sequences and 3D-MRCP sequences. 20 of the 30 patients had an established ITBL, and the remaining 10 patients were post-OLT controls. MRCPs were evaluated independently by two experienced radiologists that were blinded to the clinical history as well as the results of other imaging modalities. All images were analyzed for the presence of 16 different pathological features. Differences between ITBL patients and controls were analyzed using the Mann-Whitney-U Test. Inter-rater variability was tested using the Cohen's Kappa test. Results: Abnormal findings of bile ducts were seen in all patients. The most common findings were (in percentage for reader 1/2) intrahepatic bile duct dilatation (95 %/95 %) and extrahepatic bile duct stenoses (95 %/85 %), followed by intrahepatic main duct stenoses (90 %/95 %) and segmental duct stenoses (85 %/85 %). Differences between ITBL patients and controls were significant for most of the analyzed features (Mann-Whitney-U test, p < 0.05). For 12 of 16 features, there was substantial or almost perfect agreement (K = 0.61 - 1.00), for 2 of 16 features moderate agreement (K = 0.41- 0.60) and for 2 of 16 features fair agreement (K < 0.40). Conclusion: In patients with ITBL, MR cholangiography reveals characteristic features that may allow differentiation from other biliary complications after liver transplantation. (orig.)

PLAB and UK graduates’ performance on MRCP(UK) and MRCGP examinations: data linkage study

Science.gov (United States)

Wakeford, Richard

2014-01-01

Objectives To assess whether international medical graduates passing the two examinations set by the Professional and Linguistic Assessments Board (PLAB1 and PLAB2) of the General Medical Council (GMC) are equivalent to UK graduates at the end of the first foundation year of medical training (F1), as the GMC requires, and if not, to assess what changes in the PLAB pass marks might produce equivalence. Design Data linkage of GMC PLAB performance data with data from the Royal Colleges of Physicians and the Royal College of General Practitioners on performance of PLAB graduates and UK graduates at the MRCP(UK) and MRCGP examinations. Setting Doctors in training for internal medicine or general practice in the United Kingdom. Participants 7829, 5135, and 4387 PLAB graduates on their first attempt at MRCP(UK) Part 1, Part 2, and PACES assessments from 2001 to 2012 compared with 18 532, 14 094, and 14 376 UK graduates taking the same assessments; 3160 PLAB1 graduates making their first attempt at the MRCGP AKT during 2007-12 compared with 14 235 UK graduates; and 1411 PLAB2 graduates making their first attempt at the MRCGP CSA during 2010-12 compared with 6935 UK graduates. Main outcome measures Performance at MRCP(UK) Part 1, Part 2, and PACES assessments, and MRCGP AKT and CSA assessments in relation to performance on PLAB1 and PLAB2 assessments, as well as to International English Language Testing System (IELTS) scores. MRCP(UK), MRCGP, and PLAB results were analysed as marks relative to the pass mark at the first attempt. Results PLAB1 marks were a valid predictor of MRCP(UK) Part 1, MRCP(UK) Part 2, and MRCGP AKT (r=0.521, 0.390, and 0.490; all PIELTS scores correlated significantly with later performance, multiple regression showing that the effect of PLAB1 (β=0.496) was much stronger than the effect of IELTS (β=0.086). Changes to PLAB pass marks that would result in international medical graduate and UK medical graduate equivalence were assessed in two

PLAB and UK graduates' performance on MRCP(UK) and MRCGP examinations: data linkage study.

Science.gov (United States)

McManus, I C; Wakeford, Richard

2014-04-17

To assess whether international medical graduates passing the two examinations set by the Professional and Linguistic Assessments Board (PLAB1 and PLAB2) of the General Medical Council (GMC) are equivalent to UK graduates at the end of the first foundation year of medical training (F1), as the GMC requires, and if not, to assess what changes in the PLAB pass marks might produce equivalence. Data linkage of GMC PLAB performance data with data from the Royal Colleges of Physicians and the Royal College of General Practitioners on performance of PLAB graduates and UK graduates at the MRCP(UK) and MRCGP examinations. Doctors in training for internal medicine or general practice in the United Kingdom. 7829, 5135, and 4387 PLAB graduates on their first attempt at MRCP(UK) Part 1, Part 2, and PACES assessments from 2001 to 2012 compared with 18,532, 14,094, and 14,376 UK graduates taking the same assessments; 3160 PLAB1 graduates making their first attempt at the MRCGP AKT during 2007-12 compared with 14,235 UK graduates; and 1411 PLAB2 graduates making their first attempt at the MRCGP CSA during 2010-12 compared with 6935 UK graduates. Performance at MRCP(UK) Part 1, Part 2, and PACES assessments, and MRCGP AKT and CSA assessments in relation to performance on PLAB1 and PLAB2 assessments, as well as to International English Language Testing System (IELTS) scores. MRCP(UK), MRCGP, and PLAB results were analysed as marks relative to the pass mark at the first attempt. PLAB1 marks were a valid predictor of MRCP(UK) Part 1, MRCP(UK) Part 2, and MRCGP AKT (r=0.521, 0.390, and 0.490; all PIELTS scores correlated significantly with later performance, multiple regression showing that the effect of PLAB1 (β=0.496) was much stronger than the effect of IELTS (β=0.086). Changes to PLAB pass marks that would result in international medical graduate and UK medical graduate equivalence were assessed in two ways. Method 1 adjusted PLAB pass marks to equate median performance of PLAB

[New guidelines on chronic pancreatitis : interdisciplinary treatment strategies].

Science.gov (United States)

Lerch, M M; Bachmann, K A; Izbicki, J R

2013-02-01

Chronic pancreatitis is a common disorder associated with significant morbidity and mortality. Interdisciplinary consensus guidelines have recently updated the definitions and diagnostic criteria for chronic pancreatitis and provide a critical assessment of therapeutic procedures. Diagnostic imaging relies on endoscopic ultrasound (EUS) as the most sensitive technique, whereas computed tomography (CT) and magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP) remain a frequent preoperative requirement. Endoscopic retrograde cholangiopancreatography (ERCP) is now used mostly as a therapeutic procedure except for the differential diagnosis of autoimmune pancreatitis. Complications of chronic pancreatitis, such as pseudocysts, duct stricture and intractable pain can be treated with endoscopic interventions as well as open surgery. In the treatment of pseudocysts endoscopic drainage procedures now prevail while pain treatment has greater long-term effectiveness following surgical procedures. Currently, endocopic as well as surgical treatment of chronic pancreatitis require an ever increasing degree of technical and medical expertise and are provided increasingly more often by interdisciplinary centres. Surgical treatment is superior to interventional therapy regarding the outcome of pain control and duodenum-preserving pancreatic head resection is presently the surgical procedure of choice.

Massive pleural effusion in a young woman

Directory of Open Access Journals (Sweden)

Paolo Ghiringhelli

2012-12-01

Full Text Available Pleural effusion is a clinical manifestation shared by several underlying pathologies. The differential diagnosis is based on the clinical history, the physical examination, the analysis of the pleural fluid, and the laboratory data (mainly blood tests. There are cases, such as the patient described, where TC is not enough, and unusual imaging techniques are required for the study of pleural effusion, i.e. magnetic resonance cholangiography, cholangiopancreatography (MRCP and endoscopic retrograde cholangiopancreatography (ERCP.This case analyses a 42-year-old female patient who arrived with progressive dyspnoea, chest pain, cough, a history of alcohol abuse, and a recent episode of acute pancreatitis. The physical examination revealed signs of right-sided pleural effusion. These features, together with laboratory data, made it possible to pose the diagnosis of pancreaticopleural fistula, to treat it, and to obtain a complete healing in a two-month period.

Inaccurate preoperative imaging assessment on biliary anatomy not increases biliary complications after living donor liver transplantation

International Nuclear Information System (INIS)

Xu Xiao; Wei Xuyong; Ling Qi; Wang Kai; Bao Haiwei; Xie Haiyang; Zhou Lin; Zheng Shusen

2012-01-01

Backgrounds and aims: Accurate assessment of graft bile duct is important to plan surgical procedure. Magnetic resonance cholangiopancreatography (MRCP) has become an important diagnostic procedure in evaluation of pancreaticobiliary ductal abnormalities and has been reported as highly accurate. We aim to estimate the efficacy of preoperative MRCP on depicting biliary anatomy in living donor liver transplantation (LDLT), and to determine whether inaccurate preoperative imaging assessment would increase the biliary complications after LDLT. Methods: The data of 118 cases LDLT were recorded. Information from preoperative MRCP was assessed using intraoperative cholangiography (IOC) as the gold standard. The possible risk factors of recipient biliary complications were analyzed. Results: Of 118 donors, 84 had normal anatomy (type A) and 34 had anatomic variants (19 cases of type B, 9 cases of type C, 1 case of type E, 2 cases of type F and 3 cases of type I) confirmed by IOC. MRCP correctly predicted all 84 normal cases and 17 of 34 variant cases, and showed an accuracy of 85.6% (101/118). The incidence of biliary complications was comparable between cases with accurate and inaccurate classification of biliary tree from MRCP, and between cases with normal and variant anatomy of bile duct. While cases with graft duct opening ≤5 mm showed a significant higher incidence of total biliary complications (21.1% vs. 6.6%, P = 0.028) and biliary stricture (10.5% vs. 1.6%, P = 0.041) compared with cases with large duct opening >5 mm. Conclusion: MRCP could correctly predict normal but not variant biliary anatomy. Inaccurate assessment of biliary anatomy from MRCP not increases the rate of biliary complications, while small-sized graft duct may cause an increase in biliary complications particularly biliary stricture after LDLT.

Development of a novel fusion imaging technique in the diagnosis of hepatobiliary-pancreatic lesions

International Nuclear Information System (INIS)

Soga, Koichi; Ochiai, Jun; Miyajima, Takashi; Kassai, Kyoichi; Itani, Kenji; Yagi, Nobuaki; Naito, Yuji

2013-01-01

Multi-row detector computed tomography (MDCT) and magnetic resonance cholangiopancreatography (MRCP) play an important role in the imaging diagnosis of hepatobiliary-pancreatic lesions. Here we investigated whether unifying the MDCT and MRCP images onto the same screen using fusion imaging could overcome the limitations of each technique, while still maintaining their benefits. Moreover, because reports of fusion imaging using MDCT and MRCP are rare, we assessed the benefits and limitations of this method for its potential application in a clinical setting. The patient group included 9 men and 11 women. Among the 20 patients, the final diagnoses were as follows: 10 intraductal papillary mucinous neoplasms, 5 biliary system carcinomas, 1 pancreatic adenocarcinoma and 5 non-neoplastic lesions. After transmitting the Digital Imaging and Communication in Medicine data of the MDCT and MRCP images to a workstation, we performed a 3-D organisation of both sets of images using volume rendering for the image fusion. Fusion imaging enabled clear identification of the spatial relationship between a hepatobiliary-pancreatic lesion and the solid viscera and/or vessels. Further, this method facilitated the determination of the relationship between the anatomical position of the lesion and its surroundings more easily than either MDCT or MRCP alone. Fusion imaging is an easy technique to perform and may be a useful tool for planning treatment strategies and for examining pathological changes in hepatobiliary-pancreatic lesions. Additionally, the ease of obtaining the 3-D images suggests the possibility of using these images to plan intervention strategies.

Magnetic resonance cholangiographic (MRCP) features of ischemic-type biliary lesions (ITBL). A case-control study; Magnetresonanz-Cholangiografie (MRCP) bei Patienten mit Ischemic-Type Biliary Lesions (ITBL). Eine Fall-Kontroll-Studie

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Collettini, F.; Kroencke, T.J.; Renz, D.M.; Bucourt, M. de; Poellinger, A. [Charite, Berlin (Germany). Klinik fuer Radiologie; Heidenhain, C.; Neuhaus, P. [Charite, Berlin (Germany). Klinik fuer Allgemein-, Visceral- und Transplantationschirurgie CVK

2011-08-15

Purpose: To evaluate the spectrum of MR cholangiography (MRCP) features of ischemic-type biliary lesions (ITBL) after orthotopic liver transplantation (OLT). Materials and Methods: 30 patients (16 m, 14 f) with an average age of 52 years (9 - 69 y) were examined in two 1.5 MR units using breath-hold 2D-SS-FSE-sequences and 3D-MRCP sequences. 20 of the 30 patients had an established ITBL, and the remaining 10 patients were post-OLT controls. MRCPs were evaluated independently by two experienced radiologists that were blinded to the clinical history as well as the results of other imaging modalities. All images were analyzed for the presence of 16 different pathological features. Differences between ITBL patients and controls were analyzed using the Mann-Whitney-U Test. Inter-rater variability was tested using the Cohen's Kappa test. Results: Abnormal findings of bile ducts were seen in all patients. The most common findings were (in percentage for reader 1/2) intrahepatic bile duct dilatation (95 %/95 %) and extrahepatic bile duct stenoses (95 %/85 %), followed by intrahepatic main duct stenoses (90 %/95 %) and segmental duct stenoses (85 %/85 %). Differences between ITBL patients and controls were significant for most of the analyzed features (Mann-Whitney-U test, p < 0.05). For 12 of 16 features, there was substantial or almost perfect agreement (K = 0.61 - 1.00), for 2 of 16 features moderate agreement (K = 0.41- 0.60) and for 2 of 16 features fair agreement (K < 0.40). Conclusion: In patients with ITBL, MR cholangiography reveals characteristic features that may allow differentiation from other biliary complications after liver transplantation. (orig.)

Hepatocellular carcinoma with bile duct tumor thrombi: Correlation of magnetic resonance imaging features to histopathologic manifestations

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Liu Qingyu, E-mail: liu.qingyu@163.co [Department of Radiology, Second Affiliated Hospital of Sun Yat-sen University, 107 Yan Jiang Xi Road, Guangzhou, 510120, Guangdong Province (China); Chen Jianyu, E-mail: chenjianyu5562@sina.co [Department of Radiology, The Second Affiliated Hospital of Sun Yat-sen University, 107 Yan Jiang Xi Road, Guangzhou, 510120, Guangdong Province (China); Li Haigang, E-mail: lhg00433@yahoo.com.c [Department of Pathology, Second Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong Province (China); Liang Biling, E-mail: liangbl@163.ne [Department of Radiology, Second Affiliated Hospital of Sun Yat-sen University, 107 Yan Jiang Xi Road, Guangzhou, 510120, Guangdong Province (China); Zhang Lei, E-mail: zhanglei646@126.co [Department of Hepatobiliary Surgery, Second Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong Province (China); Hu Tao, E-mail: htwuaini@hotmail.co [Department of Radiology, Second Affiliated Hospital of Sun Yat-sen University, 107 Yan Jiang Xi Road, Guangzhou, 510120, Guangdong Province (China)

2010-10-15

Purpose: This study was to analyze the magnetic resonance imaging (MRI) features of hepatocellular carcinoma (HCC) with bile duct tumor thrombi, and explore their correlations to histopathology to improve the accuracy of diagnosis. Materials and methods: 21 patients with pathologically confirmed HCC with bile duct tumor thrombi was performed with a superconducting 1.5-T MR imager within two weeks before operation. Magnetic resonance cholangiopancreatography (MRCP) was performed on 18 patients. Images were retrospectively assessed for the size, location and MRI manifestations of HCC lesions and associated bile duct tumor thrombi. The differentiation of HCC lesions and the pathologic changes of bile duct tumor thrombi were retrospectively analyzed under microscope. Results: The average diameter of HCC lesions was 5.8 {+-} 2.8 cm, and {<=}5.0 cm in nine cases. Capsule formation was observed on MRI or pathology in 4 cases of HCC (19%). Of the 21 cases with bile duct tumor thrombi, 20 were clearly presented on MRI as cord-like or columnar masses in the bile duct with proximal cholangiectasis. The tumor thrombi showed slightly hypointense on T1WI and slightly hyperintense on T2WI. On enhanced scan, three cases of tumor thrombi, which were mainly consisted of necrotic tissue, did not show enhancement; 17 cases, which were mainly consisted of cancer cells, showed mild or moderate enhancement. On magnetic resonance cholangiopancreatogram (MRCP), 14 cases of tumor thrombi presented as filling defect in the bile duct, abrupt obstruction of the bile duct, and cholangiectasis above the obstruction; four presented as dilated intra-hepatic bile ducts with missing common bile duct. Of the 21 patients, 16 had biliary hemorrhage; three also had tumor thrombi in the portal vein. Seventeen of the 21 HCC with biliary thrombi were poorly differentiated, unencapsulated and with an invasive growth. Nineteen of 21 bile duct tumor thrombi did not invade the bile duct wall and could be

Hepatocellular carcinoma with bile duct tumor thrombi: Correlation of magnetic resonance imaging features to histopathologic manifestations

International Nuclear Information System (INIS)

Liu Qingyu; Chen Jianyu; Li Haigang; Liang Biling; Zhang Lei; Hu Tao

2010-01-01

Purpose: This study was to analyze the magnetic resonance imaging (MRI) features of hepatocellular carcinoma (HCC) with bile duct tumor thrombi, and explore their correlations to histopathology to improve the accuracy of diagnosis. Materials and methods: 21 patients with pathologically confirmed HCC with bile duct tumor thrombi was performed with a superconducting 1.5-T MR imager within two weeks before operation. Magnetic resonance cholangiopancreatography (MRCP) was performed on 18 patients. Images were retrospectively assessed for the size, location and MRI manifestations of HCC lesions and associated bile duct tumor thrombi. The differentiation of HCC lesions and the pathologic changes of bile duct tumor thrombi were retrospectively analyzed under microscope. Results: The average diameter of HCC lesions was 5.8 ± 2.8 cm, and ≤5.0 cm in nine cases. Capsule formation was observed on MRI or pathology in 4 cases of HCC (19%). Of the 21 cases with bile duct tumor thrombi, 20 were clearly presented on MRI as cord-like or columnar masses in the bile duct with proximal cholangiectasis. The tumor thrombi showed slightly hypointense on T1WI and slightly hyperintense on T2WI. On enhanced scan, three cases of tumor thrombi, which were mainly consisted of necrotic tissue, did not show enhancement; 17 cases, which were mainly consisted of cancer cells, showed mild or moderate enhancement. On magnetic resonance cholangiopancreatogram (MRCP), 14 cases of tumor thrombi presented as filling defect in the bile duct, abrupt obstruction of the bile duct, and cholangiectasis above the obstruction; four presented as dilated intra-hepatic bile ducts with missing common bile duct. Of the 21 patients, 16 had biliary hemorrhage; three also had tumor thrombi in the portal vein. Seventeen of the 21 HCC with biliary thrombi were poorly differentiated, unencapsulated and with an invasive growth. Nineteen of 21 bile duct tumor thrombi did not invade the bile duct wall and could be easily

The inconsistent nature of symptomatic pancreatico-jejunostomy anastomotic strictures

Science.gov (United States)

Demirjian, Aram N; Kent, Tara S; Callery, Mark P; Vollmer, Charles M

2010-01-01

Background Pancreatico-jejunostomy strictures (PJS) after pancreatiocoduodenectomy (PD) are poorly understood. Methods Patients treated for PJS were identified from all PDs (n =357) performed for all indications in our practice (2002 to 2009). Technical aspects of the original operation, as well as the presentation, management and outcomes of the resultant stricture were assessed. Results Seven patients developed a symptomatic PJS for an incidence of 2%. ‘Soft’ glands and small ducts (≤3 mm) were each present in 3/7 of the original anastomoses. Pancreatic fistula occurred in 6/7. The latency period to stricture presentation averaged 41 months. Diagnosis of PJS was confirmed by secretin magnetic resonance cholangio-pancreatography (MRCP). Therapeutic endoscopic retrograde cholangiopancreatography (ERCP) was attempted – each unsuccessfully – in four patients. All patients required operative correction of their PJS by takedown/revision of the original pancreatico-jejunal anastomoses (PJA) (n =4) ± a modified Puestow (n =2). One patient's PJS was completely inaccessible due to dense adhesions. Another patient's stricture recurred and was successfully revised with a stricturoplasty. At a mean follow-up of 25 months, all are alive, but only 4/7 are pain free. Conclusion A symptomatic PJS appears to be independent of original pathological, glandular or technical features but pancreatic fistulae may contribute. Secretin MRCP is diagnostically useful, whereas ERCP has been proven to be therapeutically ineffective. Durable resolution of symptoms after surgical revision is unpredictable. PMID:20815857

Comparison of ultrasound evaluation of patients of obstructive jaundice with endoscopic retrograde cholangio-pancreatography findings

International Nuclear Information System (INIS)

Farrukh, S.Z.U.I.; Siddiqui, A.R.; Haqqi, S.A.; Muhammad, A.J.

2017-01-01

Ultrasonography has proven to be quite effective in differentiating hepatocellular from obstructive cause of jaundice in various studies. This study was conducted with the aim to determine the efficacy of ultrasonography and Endoscopic Retrograde Cholangio-Pancreatography (ERCP) in the diagnosis of obstructive reason of jaundice. Methods: In this descriptive case series, 200 patients with >15 years age of either gender with cholestatic liver enzymes were included, i.e., those patients who had an ultrasound prior to ERCP at the department of gastroenterology of Patel Hospital, Karachi. Patients known to have liver disease with cholestatic jaundice had imaging other than ultrasound were excluded. The results of ultrasonography and ERCPs were compared in particularly looking for the cause of obstruction. Results: Out of total 200 patients, mean age was 41.22+-12.46 years with 107 (53.5 percent) females. Ability of ultrasound in correctly diagnosing obstructive reason for stone CBD was found to be 72.5 percent, dilated CBD without reason 41.7 percent, proximal obstruction, 63.15 percent, distal CBD obstruction 60 percent, and sludge 66.7 percent. Overall ability of ultrasound in correctly diagnosing the cause of obstruction was 64.17 percent. Conclusion: Ultrasound is recommended as the initial examination, which provides a guide to choose patients for either a more advanced non-invasive imaging like MRCP or to an invasive procedure like ERCP. (author)

Pancreatitis. An update; Pankreatitis. Ein Update

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Schreyer, A.G. [Universitaetsklinikum Regensburg, Institut fuer Roentgendiagnostik, Regensburg (Germany); Grenacher, L. [Diagnostik Muenchen, MVZ Radiologie, Muenchen (Germany); Juchems, M. [Klinikum Konstanz, Diagnostische und Interventionelle Radiologie, Konstanz (Germany)

2016-04-15

Acute and chronic pancreatitis are becoming increasingly more severe diseases in the western world with far-reaching consequences for the individual patient as well as the socioeconomic situation. This article gives an overview of the contribution of radiological imaging to the diagnostics and therapy of both forms of the disease. Acute pancreatitis can be subdivided into severe (20 %) and mild manifestations. The diagnostics should be performed with computed tomography (CT) or magnetic resonance imaging (MRI) for assessing necrosis or potential infections only in severe forms of pancreatitis. In chronic pancreatitis transabdominal ultrasound should initially be adequate for assessment of the pancreas. For the differential diagnosis between pancreatic carcinoma and chronic pancreatitis, MRI with magnetic resonance cholangiopancreatography (MRCP) followed by an endoscopic ultrasound-guided fine needle aspiration is the method of choice. For the primary diagnosis for acute and chronic pancreatitis ultrasound examination is the modality of first choice followed by radiological CT and MRI with MRCP examinations. (orig.) [German] Akute und chronische Pankreatitis sind in der westlichen Welt zunehmende schwere Krankheitsbilder mit tiefgreifenden Konsequenzen fuer den einzelnen Patienten sowie soziooekonomisch. Der Beitrag radiologischer Bildgebung zur Diagnostik und Therapie beider Erkrankungsformen soll im vorliegenden Uebersichtsbeitrag diskutiert werden. Die akute Pankreatitis kann in eine schwere (20 %) und milde Verlaufsform unterteilt werden. Lediglich bei den schweren Formen sollte eine CT- oder MRT-Diagnostik bzgl. der Beurteilung von Nekrosen und moeglichen Infektionen erfolgen. Bei der chronischen Pankreatitis genuegt zunaechst eine Beurteilung des Pankreas durch transabdominellen Ultraschall. Hier sind die MRT mit der Magnetresonanzcholangiopankreatikographie (MRCP) sowie die endosonographisch gesteuerte Feinnadelpunktion die Methode, um

Pancreas divisum: Analysis and therapeutic alternatives with a case report

Directory of Open Access Journals (Sweden)

Jokić Radoica

2013-01-01

Full Text Available Introduction. Pancreas divisum is a relatively common pancreatic duct anatomic variant, firstly described in the 17th century. Case report. We reported a 2-year-old child admitted to the Pediatric Clinic with breathing difficulties and abdominal pains. Examination and X-ray image, showed a vast right hydrothorax containing rusty coloured solution with a high degree of amylase. Ultrasound and computed tomography examination revealed pancreatic polycyclic pseudocysts; following magnetic resonance cholangiopancreatography (MRCP, the diagnosis of pancreas divisum was confirmed. The general condition of the patient worsened, requiring an urgent operation. External drainage of the perforated pancreatic pseudocyst was performed. Following external fistula maturation, a change from external to internal drainage was performed using Roux-en-Y fistulojejunostomy. A 3-year postoperative period was uneventful. Conclusion. Pancreas divisum cases are unique requiring clinical experience, rational approach, and complex multimodal management. MRCP is a valuable diagnostic method. Amongst therapeutic options, outer and internal drainage can be seen as reliable methods. Further investigations are absolutely required to determine practical and appropriate conclusions.

Quality rating of MR-cholangiopancreatography with oral application of iron oxide particles; Wertigkeit der MR-Cholangiopankreatikographie nach Gabe eines oralen eisenhaltigen Kontrastmittels

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Lorenzen, M.; Wedegaertner, U.; Fiehler, J.; Adam, G. [Universitaetsklinikum Hamburg, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie (Germany)

2003-07-01

Purpose: To compare image quality in magnetic resonance cholangiopancreatography (MRCP) performed with and without oral application of Loesferron {sup trademark} (ferrous gluconate, Lilly Pharma, Hamburg). Materials and Methods: A prospective study compares MRCPs performed on 52 patients with a 1.5 T clinical whole body scanner using a standard body coil. After randomization, patients ingested either 0.5 l of Loeseferron {sup trademark} (n=27, group 1) or no oral contrast agent (n=25, group 2) prior to the examination. 7 RARE (40 to 20 ) sequences were obtained, followed by selected 3 mm HASTE (T{sub 2}-weighted with fat suppression) sequences. After blinding, image quality was rated by two radiologists using a scale of 1 (not discernible) to 5 (very well discernible). The following sections of the biliary ductal system were evaluated: left and right hepatic duct, extrahepatic bile duct and intrapancreatic bile duct. The pancreatic duct was evaluated by its location: head, body and tail of the pancreas. A Wilcoxon-Mann-Whitney test was used to determine significant differences (p<0.05) between sampled ductal segments. Correction for multiple testing was applied. Results: The oral application of Loeseferron {sup trademark} was well tolerated by all patients, and all sequences could be acquired and evaluated in all 52 patients. For the different sections of the biliary system, the mean ratings with and without Loesferron {sup trademark} were, respectively, 3.28 and 3.36 for the left hepatic duct, 3.26 and 3.33 for the right hepatic duct, 3.46 and 4.0 for the extrahepatic bile duct, and 2.8 and 3.48 for the intrapancreatic bile duct. The corresponding ratings for the pancreatic duct were 2.8 and 3.24 for the pancreatic head, 2.84 and 3.38 for the pancreatic body, and 2.68 and 3.22 for the pancreatic tail. The differences with and without contrast agent were not statistically significant. Interobserver variability was between 0.37 for the pancreatic duct in the tail of

The use of magnetic resonance tomography in gastrointestinal diagnostics

International Nuclear Information System (INIS)

Geitung, Jonn Terje

2000-01-01

Background: Magnetic resonance imaging (MRI) is a promising method for examination of the gastrointestinal tract. In this article we present the present status and potential of MRI. Material and method: The review is based on personal experience and selected published, international papers. Results: Magnetic resonance cholangio-pancreatography (MRCP) and MRI of the liver are well documented examinations which are widely performed. These examinations partly replace existing modalities such as CT and ERCP and represent additional possibilities for examining this anatomic area. MRI is not as yet accepted as the standard examination of the pancreas, but it is regarded as comparable to CT. The adrenals may be examined even more accurately with MRI than with CT. MRI examinations of the oesophagus and gastric ventricle seem promising, but it should be said that they are in an early and not well document phase. MRI of the small and large bowels is not common. With the exception of preoperative staging of rectal cancers, it is still experimental. MR angiography, functional MRI studies and perfusion studies are not yet common in abdominal diseases. We may, however, believe that they will become important diagnostic tools. Interpretation: MRI is rapidly increasing its share of gastrointestinal imaging examinations. This is mainly due to the increased speed of newer machines. The diagnostic quality has improved and will improve more. It is thus likely that MRI will, in a large amount of abdominal imaging, replace CT and to some extent other diagnostic modalities. It is, however, not possible to replace CT for emergencies and we will probably look forward to more and better imaging with more diagnostic modalities in the future

Secretin-enhanced magnetic resonance cholangiopancreaticography: value for the diagnosis of chronic pancreatitis

International Nuclear Information System (INIS)

Heverhagen, J.T.; Burbelko, M.; Schenck zu Schweinsberg, T.; Funke, C.; Wecker, C.; Walthers, E.M.; Rominger, M.

2007-01-01

Endoscopic retrograde cholangiopancreaticography (ERCP) is the morphologic gold standard for the diagnosis of chronic pancreatitis. Magnetic Resonance Imaging (MRI) enables the visualization of not only the pancreatic duct but also the surrounding parenchyma using T2- and T1-weighted sequences before and after the application of a contrast agent. Moreover, it allows the depiction of ductal segments distal to a stenosis or occlusion. However, conventional Magnetic Resonance Cholangiopancreaticography (MRCP) was not able to achieve accuracy similar to that of ERCP. Despite many technological innovations, such as fast breath-hold acquisitions or respiratory-gated 3D sequences, this drawback could not be overcome. In recent years, secretin-enhanced MRCP has been used for the diagnosis of chronic pancreatitis. A recent study showed that secretin not only improves the visibility of the pancreatic duct and its side branches but it also enhances the diagnostic accuracy of MRCP. The sensitivity, specificity, and positive and negative predictive values were improved by the application of secretin. Moreover, the agreement between independent observers increased after the use of secretin. In addition, quantitative post-processing tools have been developed that enable the measurement of the exocrine pancreatic output non-invasively using secretin-enhanced MRCP. These tools facilitate applications, such as functional follow-up after pancreaticogastrostomy and pancreaticogastric anastomoses, evaluation of the functional status of the graft after pancreas transplantation and follow-up of pancreatic drainage procedures and duct disruption. (orig.)

Endoscopic retrograde cholangiopancreatography and endoscopic ...

African Journals Online (AJOL)

An approach to suspected gallstone pancreatitis'based on endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy (ES) was adopted in 1976 and was followed in 29 patients. ERCp became the routine method of early biliary tract assessment when gallstone pancreatitis was suspected on ...

Oral gadopentetate dimeglumine administration as a negative gastrointestinal contrast agent to improve image quality of MR cholangiopancreatography

International Nuclear Information System (INIS)

Chen Yi; Xu Yikai; Zhao Yuhui; Wang Guisheng

2008-01-01

Objective: To choose optimal concentration and volume of Gd-DTPA solution as a oral gastrointestinal negative contrast agent for MRCP. To evaluate the role of Gd-DTPA solution in improving image quality of MRCP. Methods: In vitro experiment: Gd-DTPA solution was made with different concentrations. T 1 WI, T 2 WI, two-dimensional single slice fast spin echo sequence and three-dimensional half-fourier acquisition single-shot fast spin echo sequence were performed to measure the signal intensity of these contrast agents respectively, so Gd-DTPA solution with the optimal concentration can be decided as oral negative gastrointestinal contrast agent on MRCP. Clinical study: The Gd-DTPA solution with optimal concentration and volume was regarded as an oral negative gastrointestinal contrast agent of MRCP. Twenty- four' patients were performed with MRCP before and after (5-10 minutes and 10-15 minutes) administration of oral negative gastrointestinal contrast agent and image quality was analyzed. Statistical analysis was performed using analysis of variance with SPSS 10.0. Results: When the concentration of Gd-DTPA solution was ≤0.01 mol/L, the contrast agent was hyperintense on T 1 WI. On T 2 WI, when the concentration was ≥0.015 mol/L, it was as hypointense as basic ground; On 2D FSE MRCP images, controls were hyperintense and the contrast agent with concentration ranging from 0.0025 mol/L to 0.03 mol/L was hypointense. On 3D HEAST MRCP image, controls were hyperintense and when the concentration of Gd-DTPA was ≥0.01 mol, the contrast agent was hypointense. The Gd-DTPA solution with the concentration of 0.01 mol/L and the volume of 100 ml was chosen as MRCP oral negative gastrointestinal contrast agent. On MRCP images after oral administration of the contrast agent, in 10-15 minutes, the average grade scores within 24 patients of the intrahepatic bile duct, the common hepatic bile duct, the gall bladder, the common bile duct and pancreatic duct (the average grade

Pancreatic changes in patients with primary sclerosing cholangitis: MR cholangiopancreatography and MRI findings

International Nuclear Information System (INIS)

Ozkavukcu, Esra; Erden, Ayse; Erden, Ilhan

2009-01-01

Purpose: To evaluate the possible pancreatic changes and their frequencies in patients with primary sclerosing cholangitis (PSC) on MR cholangiopancreatography (MRCP), and conventional abdominal MRI. Materials and Methods: Patient group consisted of 29 PSC (13 male, 16 female) cases, whereas cohort 1 consisted of 12 female patients with primary biliary cirrhosis, and cohort 2 consisted of 17 patients (6 male, 11 female) with non-immune chronic liver disease. Two radiologists retrospectively evaluated the MR examinations paying special attention to the pancreatic size (atrophy or enlargement), T1- and T2-signal intensity of the pancreas, focal pancreatic lesion, capsule-like rim, peripancreatic edema or fluid, fascial thickening, and pancreatic ducts (dilatation or narrowing). The results are expressed as percentages. Three groups were compared using Pearson chi-square test for each feature. However, only p-value for 'dilatation of the pancreatic duct' was determined, whereas p-value could not be calculated because of the insufficient number of subjects/sequences for the other features. Results: Twelve PSC patients (41.3%) had pancreatic abnormalities. The most common pancreatic changes in PSC patients were decreased T1-signal intensity (44%) and dilatation of the pancreatic duct (13.8%), respectively. Increased T2-signal intensity was also shown in 2 PSC patients (6.9%). Conclusion: Even PSC patients without any sign of pancreatitis, can show MR changes in the pancreatic parenchyma or the pancreatic duct. The etiologies of these changes, and whether they are unique to PSC, are still controversial. Histopathological studies bringing light to these pancreatic changes are needed.

Optimal Timing for Laparoscopic Cholecystectomy After Endoscopic Retrograde Cholangiopancreatography: A Systematic Review.

Science.gov (United States)

Friis, C; Rothman, J P; Burcharth, J; Rosenberg, J

2018-06-01

Endoscopic retrograde cholangiopancreatography followed by laparoscopic cholecystectomy is often used as definitive treatment for common bile duct stones. The aim of this study was to investigate the optimal time interval between endoscopic retrograde cholangiopancreatography and laparoscopic cholecystectomy. PubMed and Embase were searched for studies comparing different time delays between endoscopic retrograde cholangiopancreatography and laparoscopic cholecystectomy. Observational studies and randomized controlled trials were included. Primary outcome was conversion rate from laparoscopic to open cholecystectomy and secondary outcomes were complications, mortality, operating time, and length of stay. A total of 14 studies with a total of 1930 patients were included. The pooled estimate revealed an increase from a 4.2% conversion rate when laparoscopic cholecystectomy was performed within 24 h of endoscopic retrograde cholangiopancreatography to 7.6% for 24-72 h delay to 12.3% when performed within 2 weeks, to 12.3% for 2-6 weeks, and to a 14% conversion rate when operation was delayed more than 6 weeks. According to this systematic review, it is preferable to perform cholecystectomy within 24 h of endoscopic retrograde cholangiopancreatography to reduce conversion rate. Early laparoscopic cholecystectomy does not increase mortality, perioperative complications, or length of stay and on the contrary it reduces the risk of reoccurrence and progression of disease in the delay between endoscopic retrograde cholangiopancreatography and laparoscopic cholecystectomy.

Imaging of blunt pancreatic trauma: The value of initial and sequential CT examinations

International Nuclear Information System (INIS)

Szmigielski, W.; Darweesh, A.; Kassem, H.; Alhilli, S.

2008-01-01

The purpose of the study was to assess the value of initial, repeated and sequential computed tomography (CT) in patients with blunt pancreatic trauma, and then define and correlate CT findings with endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP), ultrasound (US), both laboratory and surgical findings. This retrospective study covers an eight-year period from 1999 to 2007. The material includes 21 patients (17 males and 4 females) with confirmed pancreatic injury. CT was performed on admission in all cases and in 15 cases follow-up CT was performed from 24 hrs to 14 days later. US was performed in 9 cases, ERCP in 8 cases and MRCP in one case. Serum amylase level was obtained at the admission in all cases. The CT at admission was positive in 17 patients (81.0%); the diagnosis was missed in 4 patients (19.0%), all performed on single row spiral CT. In all these four cases repeated CT was positive. ERCP showed rupture of the main pancreatic duct in 7 cases, one was inconclusive. One MRCP was positive. The serum amylase was elevated in 14 cases (66.7%) Specific CT features in initial and repeated examinations together were: organ fracture - 33.3%, swelling - 38.1%, haematoma/ contusion - 38.1%, fluid between splenic vein and pancreas - 19.0%. Non-specific features were: thickening of anterior-renal fascia- 23.8%, fluid in lesser sac - 28.6%, extra peritoneal fluid - 42.9%, associated splenic injury -14.3% and intraperitoneal fluid - 38.1%. On retrospective analysis, two out of four false negative CT results could have been avoided. No correlation between the CT features and the outcome of surgical and conservative management could be found in this study. A proper technique and accurate reading of images are mandatory for the diagnosis of pancreatic injury. When CT performed on admission is negative and there is abdominal pain and an elevated serum amylase, CT examination should be repeated within 24-48 hours

Evaluation of late stage iatrogenic extrahepatic bile duct stricture by using magnetic resonance cholangiopancreagraphy

International Nuclear Information System (INIS)

Sun Changjin; Zhou Xiangping; Liu Rongbo; Song Bin; Yan Zhihan; Chen Xian; Wang Wentao; Xiong Yan; Xu Minsheng; Gu Jianping

2003-01-01

Objective: To assess the role of magnetic resonance cholangiopancreagraphy (MRCP) in the preoperative evaluation of late stage iatrogenic extrahepatic bile duct stricture. Methods: Eighteen cases, which were diagnosed as late stage iatrogenic extrahepatic bile duct strictures only by MRCP and proved by surgery and pathology, were classified according to Bismuth classification and the surgical operation strategy was planed on the basis of MR cholangiopancreagraphic findings before surgery. The results were compared with surgery. Results: Diagnostic MR Cholangiopancreagrams were acquired in 18 patients. Among all 18 patients, the level of stricture was classified as Bismuth I in 3 patients, Bismuth II in 7 patients, Bismuth III in 3 patients, and Bismuth IV in 3 patients. A Bismuth II stricture was incorrectly classified as a Bismuth III lesion. On the basis of MR cholangiopancreagraphic findings, a surgical operation strategy can be planed. The therapeutic plan anticipated with MRCP matched the actually used procedure in 16 of 18 patients. conclusion: MRCP plays an important role in the evaluation of late stage iatrogenic extrahepatic bile duct stricture

Postprandial changes in secretory flow of pancreatic juice in the main pancreatic duct: evaluation with cine-dynamic MRCP with a spatially selective inversion-recovery (IR) pulse.

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Yasokawa, Kazuya; Ito, Katsuyoshi; Tamada, Tsutomu; Yamamoto, Akira; Hayashida, Minoru; Torigoe, Teruyuki; Tanimoto, Daigo; Higaki, Atsushi; Noda, Yasufumi; Kido, Ayumu

2016-12-01

To evaluate the influence of oral ingestion on the secretory flow dynamics of physiological pancreatic juice within the main pancreatic duct in healthy subjects by using cine-dynamic MRCP with spatially-selective inversion-recovery (IR) pulse non-invasively. Thirty-eight healthy subjects were investigated. MRCP with spatially-selective IR pulse was repeated every 15 s for 5 min to acquire a total of 20 images (cine-dynamic MRCP). A set of 20 MRCP images was repeatedly obtained before and after liquid oral ingestion every 7 min (including 2-min interval) for 40 min (a total of seven sets). Secretion grade of pancreatic juice on cine-dynamic MRCP was compared before and after oral ingestion using the nonparametric Wilcoxon signed-rank test. Median secretion grades of pancreatic juice at 5 min (score = 2.15), 12 min (score = 1.95) and 19 min (score = 2.05) after ingestion were significantly higher than that before ingestion (score = 1.40) (P = 0.004, P = 0.032, P = 0.045, respectively). Secretion grade of pancreatic juice showed a maximum peak of 2.15 at 5 min after ingestion. Thereafter, the secretion grade of pancreatic juice tended to gradually decline. Non-invasive cine-dynamic MRCP using spatially-selective IR pulse showed potential for evaluating postprandial changes in the secretory flow dynamics of pancreatic juice as a physiological reaction. • Secretion grade of pancreatic juice at cine-dynamic MRCP after ingestion was evaluated. • Secretion grade was significantly increased within 19 min after liquid meal ingestion. • Secretion grade showed maximum peak of 2.15 at 5 min after ingestion. • Postprandial changes in pancreatic juice flow can be assessed by cine-dynamic MRCP.

Postprandial changes in secretory flow of pancreatic juice in the main pancreatic duct: evaluation with cine-dynamic MRCP with a spatially selective inversion-recovery (IR) pulse

International Nuclear Information System (INIS)

Yasokawa, Kazuya; Ito, Katsuyoshi; Tamada, Tsutomu; Yamamoto, Akira; Hayashida, Minoru; Torigoe, Teruyuki; Tanimoto, Daigo; Higaki, Atsushi; Noda, Yasufumi; Kido, Ayumu

2016-01-01

To evaluate the influence of oral ingestion on the secretory flow dynamics of physiological pancreatic juice within the main pancreatic duct in healthy subjects by using cine-dynamic MRCP with spatially-selective inversion-recovery (IR) pulse non-invasively. Thirty-eight healthy subjects were investigated. MRCP with spatially-selective IR pulse was repeated every 15 s for 5 min to acquire a total of 20 images (cine-dynamic MRCP). A set of 20 MRCP images was repeatedly obtained before and after liquid oral ingestion every 7 min (including 2-min interval) for 40 min (a total of seven sets). Secretion grade of pancreatic juice on cine-dynamic MRCP was compared before and after oral ingestion using the nonparametric Wilcoxon signed-rank test. Median secretion grades of pancreatic juice at 5 min (score = 2.15), 12 min (score = 1.95) and 19 min (score = 2.05) after ingestion were significantly higher than that before ingestion (score = 1.40) (P = 0.004, P = 0.032, P = 0.045, respectively). Secretion grade of pancreatic juice showed a maximum peak of 2.15 at 5 min after ingestion. Thereafter, the secretion grade of pancreatic juice tended to gradually decline. Non-invasive cine-dynamic MRCP using spatially-selective IR pulse showed potential for evaluating postprandial changes in the secretory flow dynamics of pancreatic juice as a physiological reaction. (orig.)

Postprandial changes in secretory flow of pancreatic juice in the main pancreatic duct: evaluation with cine-dynamic MRCP with a spatially selective inversion-recovery (IR) pulse

Energy Technology Data Exchange (ETDEWEB)

Yasokawa, Kazuya; Ito, Katsuyoshi; Tamada, Tsutomu; Yamamoto, Akira; Hayashida, Minoru; Torigoe, Teruyuki; Tanimoto, Daigo; Higaki, Atsushi; Noda, Yasufumi; Kido, Ayumu [Kawasaki Medical School, Department of Diagnostic Radiology, Kurashiki, Okayama (Japan)

2016-12-15

To evaluate the influence of oral ingestion on the secretory flow dynamics of physiological pancreatic juice within the main pancreatic duct in healthy subjects by using cine-dynamic MRCP with spatially-selective inversion-recovery (IR) pulse non-invasively. Thirty-eight healthy subjects were investigated. MRCP with spatially-selective IR pulse was repeated every 15 s for 5 min to acquire a total of 20 images (cine-dynamic MRCP). A set of 20 MRCP images was repeatedly obtained before and after liquid oral ingestion every 7 min (including 2-min interval) for 40 min (a total of seven sets). Secretion grade of pancreatic juice on cine-dynamic MRCP was compared before and after oral ingestion using the nonparametric Wilcoxon signed-rank test. Median secretion grades of pancreatic juice at 5 min (score = 2.15), 12 min (score = 1.95) and 19 min (score = 2.05) after ingestion were significantly higher than that before ingestion (score = 1.40) (P = 0.004, P = 0.032, P = 0.045, respectively). Secretion grade of pancreatic juice showed a maximum peak of 2.15 at 5 min after ingestion. Thereafter, the secretion grade of pancreatic juice tended to gradually decline. Non-invasive cine-dynamic MRCP using spatially-selective IR pulse showed potential for evaluating postprandial changes in the secretory flow dynamics of pancreatic juice as a physiological reaction. (orig.)

Increased cholestatic enzymes in two patients with long-term history of ulcerative colitis: consider primary biliary cholangitis not always primary sclerosing cholangitis.

Science.gov (United States)

Polychronopoulou, Erietta; Lygoura, Vasiliki; Gatselis, Nikolaos K; Dalekos, George N

2017-09-25

Several hepatobiliary disorders have been reported in ulcerative colitis (UC) patients with primary sclerosing cholangitis (PSC) being the most specific. Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, rarely occurs in UC. We present two PBC cases of 67 and 71 years who suffered from long-standing UC. Both patients were asymptomatic but they had increased cholestatic enzymes and high titres of antimitochondrial antibodies (AMA)-the laboratory hallmark of PBC. After careful exclusion of other causes of cholestasis by MRI/magnetic resonance cholangiopancreatography (MRCP), virological and microbiological investigations, a diagnosis of PBC associated with UC was established. The patients started ursodeoxycholic acid (13 mg/kg/day) with complete response. During follow-up, both patients remained asymptomatic with normal blood biochemistry. Although PSC is the most common hepatobiliary manifestation among patients with UC, physicians must keep also PBC in mind in those with unexplained cholestasis and repeatedly normal MRCP. In these cases, a reliable AMA testing can help for an accurate diagnosis. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Implementing statistical equating for MRCP(UK) Parts 1 and 2.

Science.gov (United States)

McManus, I C; Chis, Liliana; Fox, Ray; Waller, Derek; Tang, Peter

2014-09-26

The MRCP(UK) exam, in 2008 and 2010, changed the standard-setting of its Part 1 and Part 2 examinations from a hybrid Angoff/Hofstee method to statistical equating using Item Response Theory, the reference group being UK graduates. The present paper considers the implementation of the change, the question of whether the pass rate increased amongst non-UK candidates, any possible role of Differential Item Functioning (DIF), and changes in examination predictive validity after the change. Analysis of data of MRCP(UK) Part 1 exam from 2003 to 2013 and Part 2 exam from 2005 to 2013. Inspection suggested that Part 1 pass rates were stable after the introduction of statistical equating, but showed greater annual variation probably due to stronger candidates taking the examination earlier. Pass rates seemed to have increased in non-UK graduates after equating was introduced, but was not associated with any changes in DIF after statistical equating. Statistical modelling of the pass rates for non-UK graduates found that pass rates, in both Part 1 and Part 2, were increasing year on year, with the changes probably beginning before the introduction of equating. The predictive validity of Part 1 for Part 2 was higher with statistical equating than with the previous hybrid Angoff/Hofstee method, confirming the utility of IRT-based statistical equating. Statistical equating was successfully introduced into the MRCP(UK) Part 1 and Part 2 written examinations, resulting in higher predictive validity than the previous Angoff/Hofstee standard setting. Concerns about an artefactual increase in pass rates for non-UK candidates after equating were shown not to be well-founded. Most likely the changes resulted from a genuine increase in candidate ability, albeit for reasons which remain unclear, coupled with a cognitive illusion giving the impression of a step-change immediately after equating began. Statistical equating provides a robust standard-setting method, with a better

Treatment of Duodenal Duplication by Trans-umbilical Exploratory Minimal Laparotomy

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Li-Lan Chiang

2009-08-01

Full Text Available Duodenal duplication cysts are rare congenital lesions. Their presentation is often non-specific and physical examination and laboratory studies usually reveal no abnormal findings. The diagnosis of duodenal duplication cysts can thus be challenging and relies on ultrasonography, barium swallow, contrast enhanced computed tomography (CT, magnetic resonance imaging (MRI, and magnetic resonance cholangiopancreatography (MRCP. The management of duodenal duplication cyst is surgical. Laparotomy is usually necessary, and complete resection is the management goal. Subtotal excision with stripping of the mucosa due to close involvement of the pancreatobiliary tree, and endoscopic resection have Duodenal duplication cysts are rare congenital lesions usually diagnosed in infancy, although they may present in adulthood. Prenatal diagnosis is difficult, and postnatal diagnosis relies on ultrasonography, barium swallow, contrast-enhanced computerized tomography, magnetic resonance imaging (MRI, and magnetic resonance cholangiopancreatography. A female newborn was diagnosed with an abdominal cyst (size around 6 ×; 5 × 4 cm at gestational age (GA 24 weeks, by regular prenatal examination. After her birth at GA 37 weeks, we performed abdominal ultrasonography and MRI, but there was no definite diagnosis. The usual management of an abdominal cyst involves resection by laparotomy (requiring a large incision or laparoscopy (requiring several small incisions. We performed an exploratory trans-umbilical minimal laparotomy excision for surgery, and the pathology revealed duodenal duplication. In our case, there was no recurrence of the cyst after 18 months follow-up, and the operation scar was almost undetectable. Trans-umbilical minimal laparotomy excision may be considered as an alternative choice for the management of abdominal and duodenal duplication cysts.

Primary Follicular Lymphoma of the Common Bile Duct Mimicking Cholangiocarcinoma

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Khaled Youssef Elbanna

2014-01-01

Full Text Available Primary non-Hodgkin′s lymphoma of the common bile duct is extremely rare. We present a case with history of inflammatory bowel disease and clinical manifestations of obstructive jaundice. Abdominal magnetic resonance imaging with magnetic resonance cholangiopancreatography (MRCP was done and demonstrated tight stricture at the middle part of common bile duct, and radiological findings were supportive of extra-hepatic cholangiocarcinoma. Whipple′s procedure was performed and the case was histopathologically proven to be non-Hodgkin′s lymphoma of follicular subtype involving the common bile duct. Lymphoma of the hepatobiliary system is usually present as secondary manifestation of systemic malignant lymphoma. However, primary malignant lymphomas arising from the hepatobiliary tree are extremely rare. The radiological appearance of common bile duct lymphoma is very similar to cholangiocarcinoma, making preoperative diagnosis very difficult, as in our present case. We also compare the imaging findings of our case to those seen in reported cases of follicular lymphoma of the common bile duct.

Value of selective MIP reconstructions of respiratory triggered 3D-TSE-MR cholangiography on a workstation versus standard MIP reconstructions and single-shot MRCP

International Nuclear Information System (INIS)

Schaible, R.; Textor, J.; Kreft, B.; Schild, H.; Neubrand, M.

2001-01-01

Comparison of anatomical visualisation and diagnostic value of selective MIP reconstructions of respiratory triggered 3D-TSE-MRCP versus standard MIP reconstructions and single-shot MRCP. Material and Methods: 50 patients with pancreaticobiliary disease were examined at 1.5 Tesla (ACS NT II, Philips Medical Systems) using a breath-hold single-shot (SS) and a respiratory triggered 3D-TSE-MRCP technique in 12 standard MIP projections. Additional selective MIP reconstructions with different slice thickness (2, 4, 10 cm) and projections were performed on a workstation. Visualization of the pancreaticobiliary system and the diagnostic value of the examinations were analysed. Results: Single-shot and 3D-TSE in standard projections showed comparable anatomical visualisation. On selective MIP reconstructions the biliary system (SS p [de

MR imaging and MR cholangiopancreatography in the preoperative evaluation of hilar cholangiocarcinoma: correlation with surgical and pathologic findings

Energy Technology Data Exchange (ETDEWEB)

Masselli, Gabriele; Gualdi, Gianfranco [Umberto I Hospital-La Sapienza University Rome, Department of Radiology, Rome (Italy); Manfredi, Riccardo [University of Verona, Department of Radiology, Verona (Italy); Vecchioli, Amorino [A. Gemelli Hospital-University of Sacred Heart, Department of Radiology, Rome (Italy)

2008-10-15

The primary aim was to evaluate delayed contrast-enhanced MRI in depicting perineural spread of hilar cholangiocarcinoma (CCC) and consequently to determine the capability of MRI/MRCP for staging CCC. Fifteen patients that underwent MRI/MRCP and surgical treatment were retrospectively included. Two radiologists evaluated MR images to assess delayed periductal enhancement, extent of bile duct stenosis, liver parenchymal and vascular involvement and presence of liver atrophy. An agreement between delayed enhancement of the bile duct walls and perineural neoplastic spread showed a very good correlation factor (0.93). The overall accuracy in detecting biliary neoplastic invasion was higher for delayed T1-weighted images (93.3%) than for the MRCP images (80%), and T1-delayed image increased the MR accuracy in assessing the neoplastic resectability (p < 0.05). MRI correctly predicted vascular involvement in 73% and liver involvement in 80% of the cases. The number of overall correctly assessed patients with regard to resectability was 11 true positive, 1 false positive and 3 true negative. The combination of MRI/MRCP is a reliable diagnostic method for staging hilar cholangiocarcinomas. Delayed periductal enhancement is accurate in the evaluation of neoplastic perineural spread, and it can improve diagnostic accuracy to identify resectable and unresectable tumours. (orig.)

Anatomic variants of the pancreatic duct and their clinical relevance: an MR-guided study in the general population

International Nuclear Information System (INIS)

Buelow, Robin; Thiel, Robert; Thamm, Patrick; Messner, Philip; Hosten, Norbert; Kuehn, Jens-Peter; Simon, Peter; Lerch, Markus M.; Mayerle, Julia; Voelzke, Henry

2014-01-01

To investigate the frequency of pancreatic duct (PD) variants and their effect on pancreatic exocrine function in a population-based study using non-invasive secretin-stimulated magnetic resonance cholangiopancreatography (sMRCP). Nine hundred and ninety-five volunteers, 457 women and 538 men, aged 51.9 ± 13.4 years, underwent navigator-triggered, T2-weighted, 3D turbo spin echo MRCP on a 1.5 T system after 1 unit/kg secretin administration. Two readers evaluated images for PD variants. Pancreatic exocrine function and morphological signs of chronic pancreatitis such as abnormalities of the main PD, side branch dilatation, and pancreatic cysts were evaluated and related to PD variants using a Kruskal-Wallis test and post hoc analysis. Of all sMRCP, 93.2 % were of diagnostic quality. Interobserver reliability for detection of PD variants was found to be kappa 0.752 (95 %CI, 0.733 - 0.771). Normal PD variants were observed in 90.4 % (n = 838/927). Variants of pancreas divisum was identified in 9.6 % (n = 89/927). Abnormalities of the main PD, side branch dilatation, and pancreatic cysts were observed in 2.4 %, 16.6 %, and 27.7 %, respectively, and were not significantly different between pancreas divisum and non-divisum group (P = 0.122; P = 0.152; P = 0.741). There was no association between PD variants and pancreatic exocrine function (P = 0.367). PD variants including pancreas divisum are not associated with morphological signs of chronic pancreatitis or restriction of pancreatic exocrine function. (orig.)

Anatomic variants of the pancreatic duct and their clinical relevance: an MR-guided study in the general population

Energy Technology Data Exchange (ETDEWEB)

Buelow, Robin; Thiel, Robert; Thamm, Patrick; Messner, Philip; Hosten, Norbert; Kuehn, Jens-Peter [University Medicine, Ernst Moritz Arndt University Greifswald, Department of Radiology and Neuroradiology, Greifswald (Germany); Simon, Peter; Lerch, Markus M.; Mayerle, Julia [University Medicine, Ernst Moritz Arndt University Greifswald, Division of Gastroenterology and Department of Medicine A, Greifswald (Germany); Voelzke, Henry [University Medicine, Ernst Moritz Arndt University Greifswald, Institute for Community Medicine, Greifswald (Germany)

2014-12-15

To investigate the frequency of pancreatic duct (PD) variants and their effect on pancreatic exocrine function in a population-based study using non-invasive secretin-stimulated magnetic resonance cholangiopancreatography (sMRCP). Nine hundred and ninety-five volunteers, 457 women and 538 men, aged 51.9 ± 13.4 years, underwent navigator-triggered, T2-weighted, 3D turbo spin echo MRCP on a 1.5 T system after 1 unit/kg secretin administration. Two readers evaluated images for PD variants. Pancreatic exocrine function and morphological signs of chronic pancreatitis such as abnormalities of the main PD, side branch dilatation, and pancreatic cysts were evaluated and related to PD variants using a Kruskal-Wallis test and post hoc analysis. Of all sMRCP, 93.2 % were of diagnostic quality. Interobserver reliability for detection of PD variants was found to be kappa 0.752 (95 %CI, 0.733 - 0.771). Normal PD variants were observed in 90.4 % (n = 838/927). Variants of pancreas divisum was identified in 9.6 % (n = 89/927). Abnormalities of the main PD, side branch dilatation, and pancreatic cysts were observed in 2.4 %, 16.6 %, and 27.7 %, respectively, and were not significantly different between pancreas divisum and non-divisum group (P = 0.122; P = 0.152; P = 0.741). There was no association between PD variants and pancreatic exocrine function (P = 0.367). PD variants including pancreas divisum are not associated with morphological signs of chronic pancreatitis or restriction of pancreatic exocrine function. (orig.)

Endoscopic retrograde cholangiopancreatography causes reduced myocardial blood flow

DEFF Research Database (Denmark)

Christensen, M; Hendel, H W; Rasmussen, V

2002-01-01

BACKGROUND AND STUDY AIMS: Previous studies have shown that up to 50% of healthy patients may develop ST-segment changes during upper gastrointestinal endoscopy. The aim of the study was to evaluate myocardial blood flow in patients during endoscopic retrograde cholangiopancreatography (ERCP...

Evaluation of pancreatic exocrine insufficiency by cine-dynamic MRCP using spatially selective inversion-recovery (IR) pulse: Correlation with severity of chronic pancreatitis based on morphological changes of pancreatic duct.

Science.gov (United States)

Yasokawa, Kazuya; Ito, Katsuyoshi; Kanki, Akihiko; Yamamoto, Akira; Torigoe, Teruyuki; Sato, Tomohiro; Tamada, Tsutomu

2018-05-01

To evaluate the correlation between the pancreatic exocrine insufficiency estimated by cine-dynamic MRCP using spatially selective IR pulse and the severity stages (modified Cambridge classification) based on morphological changes of the pancreatic duct in patients with suspected chronic pancreatitis. Thirty-nine patients with suspected chronic pancreatitis underwent cine-dynamic MRCP with a spatially selective IR pulse. The secretion grading score (5-point scale) based on the moving distance of pancreatic juice inflow on cine-dynamic MRCP was assessed, and compared with the stage of the severity of chronic pancreatitis based on morphological changes of pancreatic duct. The stage of the severity of chronic pancreatitis based on morphological changes had significant negative correlations with the secretion grade (r=-0.698, P0.70 in 2 (33%) of 6 patients showing normal pancreatic exocrine function. It should be noted that the degree of morphological changes of pancreatic duct does not necessarily reflect the severity of pancreatic exocrine insufficiency at cine-dynamic MRCP in stage 2-3 chronic pancreatitis. Copyright © 2017 Elsevier Inc. All rights reserved.

Vagal withdrawal during endoscopic retrograde cholangiopancreatography

DEFF Research Database (Denmark)

Christensen, M; Rasmussen, Verner; Schulze, S

2000-01-01

BACKGROUND: Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) are at risk of developing cardiorespiratory complications, but the mechanism is still unknown. Treatment with metoprolol 2 h before the endoscopy has been shown to decrease the incidence of myocardial ischaemia......: The existence of a defence-like reaction ('vagal withdrawal') during ERCP has been shown. Metoprolol given 2 h before the procedure did not affect the occurrence of this phenomenon. The interaction of other periendoscopic factors is still unclear and should be studied further....

Huge biloma after endoscopic retrograde cholangiopancreatography and endoscopic biliary sphincterotomy

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Harith M. Alkhateeb

2015-01-01

Conclusions: (1 Following endoscopic retrograde cholangiopancreatography, a patient’s complaints should not be ignored. (2 A massive biloma can occur due to such procedures. (3 Conservative treatment with minimal invasive technique can prove to be effective.

An unusual experience with endoscopic retrograde cholangiopancreatography

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Mallikarjun Patil

2013-01-01

Full Text Available The endoscopic retrograde cholangiopancreatography (ERCP is known for its varied diagnostic and therapeutic utility for a variety of disorders. However it has greater likelihood of procedure related complications among the endoscopic procedures of gastrointestinal tract. The extraluminal hemorrhagic complications following ERCP are potentially life threatening though relatively rare. We present a 50 year patient with choledocholithiasis and cholelithiasis developing rare complication of subcapsular hepatic hematoma, following ERCP due to guide wire injury.

Imaging of the intrabiliary rupture of hepatic hydatid cysts

International Nuclear Information System (INIS)

Liu Wenya; Wang Jian; Liu Xinli

2009-01-01

Objective: To discuss the imaging features of ultrasonography (USG), CT /CT cholangiography (CTC), MR/MR cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) of the hepatic hydatid cysts ruptured into biliary duct, and to evaluate the diagnostic efficacy of different modalities. Methods: Fifty one cases of hepatic hydatid cysts with intrabiliary rupture were divided into 4 groups according to imaging modality used to study these cases. 46 cases, 41 cases, 35 cases and 14 cases were examined by USG, CT, MRCP and ERCP respectively. Comparison of the imaging findings from different imaging modalities with surgical results were made to evaluate the efficacy of each imaging modality. Analysis of χ 2 were performed for the positive predictive value among the 4 groups. Results: The positive predictive values of these four methods in diagnosing the intrabiliary rupture of liver hydatid cyst were 67.4% (31/46), 80.5% (33/41), 94.3% (33/35)and respectively (χ 2 =13.1370, P<0.05). There were statistical difference between USG and 100.0% (14/14) MRCP (P<0.0084). The direct manifestations of intrabiliary rupture of hepatic hydatid cysts on USG, CT, MRCP and ERCP were as following: (1) Communication break point was seen in 3/46,3/41,9/35 and 13/14 eases respectively; (2) Increased biliary density due to the presence of membrane of echinococcus cysts and daughter cysts were seen in 5/46, 6/41,6/35 and 8/14 cases respectively; (3) Lesions adjacent to bile duct, gall bladder wall thickening, and/or interruption of bile duct, remote biliary dilatation were seen in 24/46, 26/41, 31/35 and 8/14 of cases respectively. Indirect signs included: (1) Cyst collapse, increased cyst fluid density were seen in 30/46, 33/41, 27/35 and 0/14 of cases respectively; (2) Detached membrane signs were seen in 21/46, 24/41,22/35 and 0/14; (3) Dilatation of adjacent hepatic bile duct were seen in 30/46, 29/41, 34/35 and 6/14 of cases respectively. Conclusions: Both

Importance of early diagnosis of pancreaticobiliary maljunction without biliary dilatation

Science.gov (United States)

Takuma, Kensuke; Kamisawa, Terumi; Tabata, Taku; Hara, Seiichi; Kuruma, Sawako; Inaba, Yoshihiko; Kurata, Masanao; Honda, Goro; Tsuruta, Koji; Horiguchi, Shin-ichiro; Igarashi, Yoshinori

2012-01-01

AIM: To clarify the strategy for early diagnosis of pancreaticobiliary maljunction (PBM) without biliary dilatation and to pathologically examine gallbladder before cancer develops. METHODS: The anatomy of the union of the pancreatic and bile ducts was assessed by using endoscopic retrograde cholangiopancreatography (ERCP). Patients with a long common channel in which communication between the pancreatic and bile ducts was maintained even during sphincter contraction were diagnosed as having PBM. Of these, patients in which the maximal diameter of the bile duct was less than 10 mm were diagnosed with PBM without biliary dilatation. The process of diagnosing 54 patients with PBM without biliary dilatation was retrospectively investigated. Histopathological analysis of resected gallbladder specimens from 8 patients with PBM without biliary dilatation or cancer was conducted. RESULTS: Thirty-six PBM patients without biliary dilatation were diagnosed with gallbladder cancer after showing clinical symptoms such as abdominal or back pain (n = 16) or jaundice (n = 12). Radical surgery for gallbladder cancer was only possible in 11 patients (31%) and only 4 patients (11%) survived for 5 years. Eight patients were suspected as having PBM without biliary dilatation from the finding of gallbladder wall thickening on ultrasound and the diagnosis was confirmed by ERCP and/or magnetic resonance cholangiopancreatography (MRCP). The median age of these 8 patients was younger by a decade than PBM patients with gallbladder cancer. All 8 patients underwent prophylactic cholecystectomy and bile duct cancer has not occurred. Wall thickness and mucosal height of the 8 resected gallbladders were significantly greater than controls, and hyperplastic changes, hypertrophic muscular layer, subserosal fibrosis, and adenomyomatosis were detected in 7 (88%), 5 (63%), 7 (88%) and 5 (63%) patients, respectively. Ki-67 labeling index was high and K-ras mutation was detected in 3 of 6 patients

Imaging diagnosis of intraductal papillary mucinous tumor of the pancreas

International Nuclear Information System (INIS)

Zhang Huimao; Lai Ying; Yang Shuqin; Yang Haishan; Murakami, K.

2005-01-01

Objective: To explore the diagnostic value of intraductal papillary mucinous tumor (IPMT) of the pancreas, and to assess its clinical and characteristic radiological features. Methods: Thirty-six cases with IPMT who underwent CT and MRI with plain and contrast enhancement before operation were reviewed. The clinical presentation and characteristic imaging findings of main duct type (8 cases) and branch duct type (28 cases) were retrospectively reviewed. Results: Typical imaging findings of main duct type were segmental or diffuse dilation of MPD (diameter was over 9 mm) with enhanced mural nodules after contrast medium administration. MR cholangiopancreatography (MRCP) showed dilation of MPD with flat/nodule filling defects in 4 cases and MPD dilatation in the head side in 2 cases. Branch duct type was more frequently located in the head or uncinate. Typical imaging findings of branch duct type were unilocular or multilocular cystic tumors with septa, mural nodules, and MPD dilatation. MRCP showed septa in 24 cases, filling defects in 15 cases, and MPD dilatation in 8 cases. Communication between the cystic lesion and the MPD was demonstrated in 19 cases by MRCP. Conclusion: It is extremely important to accurately make the diagnosis of IPMT for planning the surgical strategy. MRCP is a noninvasive and useful method in detecting and making definite diagnosis of IPMT. (authors)

Efficiency of the confocal method of laser endomicroscopy in complex diagnoses of diseases of common bile duct

International Nuclear Information System (INIS)

Anaskin, S G; Korniletsky, I D; Panchenkov, D N; Chertyuk, V B; Sazonov, D V; Zabozlayev, F G; Danilevskaya, O V; Mokshina, N V

2017-01-01

One of the more frequent manifestations of diseases of the bile ducts are its’ strictures or stenoses that could be of either malignant or benign nature. Current methods of diagnosing this pathology include computer tomography (CT) scan, magnetic resonance cholangiopancreatography (MRCP), endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP). However, these methods are not always informative, which makes this a current and topical problem. A fundamentally new method that broadens the capabilities of ERCP when diagnosing diseases of the bile duct accompanied by the development of strictures or stenoses is probe-based confocal laser endomicroscopy (pCLE). The method is based on the principle of confocal fluorescence microscopy. The most elaborate complications arise with the presence of the pre-existing pancreatobiliary pathology: pseudotumoral chronic pancreatitis, acute cholangitis, etc. Early stage cholangiocarcinoma diagnosis can be difficult (and not always possible) even with the help of modern research methods. For the timely diagnostic it is advantageous to conduct pCLE and targeted biopsy of the zone with most manifested changes. In all instances, the first use of the pCLE method for diagnostic purposes allowed us to clarify and correctly verify the diagnosis. When concerning the diseases of the bile duct, the modern stage of pCLE development can be of critical importance when other methods are not effective. (paper)

Choledocholithiasis: Evolving standards for diagnosis and management

Institute of Scientific and Technical Information of China (English)

Marilee L Freitas; Robert L Bell; Andrew J Duffy

2006-01-01

Cholelithiasis, one of the most common medical conditions leading to surgical intervention, affects approximately 10 % of the adult population in the United States.Choledocholithiasis develops in about 10%-20% of patients with gallbladder stones and the literature suggests that at least 3%-10% of patients undergoing cholecystectomy will have common bile duct (CBD) stones.CBD stones may be discovered preoperatively, intraoperatively or postoperatively Multiple modalities are available for assessing patients for choledocholithiasis including laboratory tests, ultrasound, computed tomography scans (CT), and magnetic resonance cholangiopancreatography (MRCP). Intraoperative cholangiography during cholecystectomy can be used routinely or selectively to diagnose CBD stones.The most common intervention for CBD stones is ERCP. Other commonly used interventions include intraoperative bile duct exploration, either laparoscopic or open. Percutaneous, transhepatic stone removal other novel techniques of biliary clearance have been devised.The availability of equipment and skilled practitioners who are facile with these techniques varies among institutions. The timing of the intervention is often dictated by the clinical situation.

Advances in endoscopic retrograde cholangiopancreatography

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WANG Xiangping

2018-03-01

Full Text Available Endoscopic retrograde cholangiopancreatography (ERCP is a well-established advanced endoscopic technique for the diagnosis and treatment of pancreatobiliary diseases. New advances have been made in the treatment concept and techniques of ERCP in recent years. This article elaborates on the recent advances in ERCP, including the application of pancreatic duct stent, non-steroidal anti-inflammatory drugs, and aggressive hydration to prevent postoperative pancreatitis, covered metal stent for the treatment of benign bile duct stenosis, intraluminal radiofrequency ablation for malignant bile duct stenosis, extracorporeal shockwave lithotripsy and covered metal stent for the treatment of chronic pancreatitis, peroral choledochoscopy for qualitative diagnosis of bile duct stenosis and huge refractory stones, definition of difficult intubation, timing of pre-cut technique, and ERCP after gastrointestinal reconstruction.

Does Courvoisier's sign stand the test of time?

International Nuclear Information System (INIS)

Murphy, K.; McLaughlin, P.; O'Connor, B.R.; Breen, M.; O'Súilleabháin, C.; MacEneaney, P.; Maher, M.M.

2012-01-01

Aim: To investigate the validity of Courvoisier's sign, in the age of cross-sectional imaging and image analysis software by objectively measuring gallbladder volumes at magnetic resonance cholangiopancreatography (MRCP) in patients with and without biliary obstruction and to assess whether gallbladder volume is more significantly increased in patients with gallstone-related rather than non-gallstone-related biliary obstruction. Materials and methods: All MCRP investigations that were performed at a tertiary hepatobiliary centre over a 2-year period were analysed. The information recorded included the presence or absence of gallbladder stones as well as the presence and type of common bile duct (CBD) disease. Gallbladder volume was calculated from MRCP studies using image analysis software. Results: Three hundred and ninety-four of 645 examined MRCPs (61.1%) were eligible for analysis. A statistically significant difference in mean gallbladder volume existed between the summated obstructive and non-obstructive groups (p < 0.001). In addition, a significant difference existed in mean gallbladder volume between those with CBD stones and non-gallstone CBD obstruction (p = 0.03). Conclusion: A significant difference was observed in gallbladder volumes in the group with biliary obstruction from choledocholithiasis compared with the group with biliary obstruction from other causes. Thus, objective measurement of gallbladder volume from modern cross-sectional imaging studies appears to validate Courvoisier's sign as a valuable clinical sign, which could be applied to modern imaging studies in distinguishing different causes of biliary obstruction in the jaundiced patient.

Factors that affect the variability in heart rate during endoscopic retrograde cholangiopancreatography

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Christensen, Merete; Reinert, Rebekka; Rasmussen, Verner

2002-01-01

OBJECTIVE: To find out if drugs, position, and endoscopic manipulation during endoscopic retrograde cholangiopancreatography (ERCP) influence the changes in the variability of heart rate. DESIGN: Single-blind randomised trial. SUBJECTS: 10 volunteers given butyscopolamine, glucagon, or saline...

Utility of single shot fast spin echo technique in evaluating pancreaticobiliary diseases: T2-weighted image and magnetic resonance cholangiopancreatography

International Nuclear Information System (INIS)

Choi, Byoung Wook; Kim, Myeong Jin; Chung, Jae Bok; Ko, Heung Kyu; Kim, Dong Joon; Kim, Joo Hee; Chung, Jae Joon; Yoo, Hyung Sik; Lee, Jong Tae

1999-01-01

To evaluate the accuracy of T2-weighted imaging an MR cholangiopancreatography using the single shot fast spin-echo technique for evaluating pancreaticobiliary disease. Between March and July 1997, axial and coronal T2-weighted images(TE: 80-200 msec) and MR cholangiopancreatograms (TE: 800-1200 msec) were obtained in two ways [single slab (thickness: 30-50 mm) and multislice acquisition under chemical fat saturation] using SSFSE pulse sequencing in 131 cases of suspected pancreati-cobiliary disease. The accuracy of SSFSE MR imaging was assessed in 89 lesions of 74 patients [male, 48; female, 26; age range, 30-86 (mean, 59) years] confirmed surgicopathologically (50 lesions in 39 patients) and clinically (39 lesions in 35 patients). Two radiologists reviewed the MR images and diagnosis was determined by consensus. Correct diagnosis was confirmed in 84 of 89 lesions (94%). Seven lesions were falsely interpreted, false positive and false negative results accounting for two and five cases, respectively. Two pancreatic cancers were misdiagnosed as pancreatitis and a cancer of the proximal common bile duct(CBD) was interpreted as a distal CBD cancer. The sensitivity of SSFSE MR imaging for malignancy was 93 %. One CBD stone revealed by endoscopic retrograde cholangiopancreatography (ERCP) was not detected on MR images. In contrast, a stone in the CBD seen on MR images was not apparent on subsequent ERCP. Sensitivity and specificity for calculous disease were 96% and 99.7%, respectively. A benign stricture of the ampulla of Vater was falsely interpreted as normal, and correct diagnosis was possible in two falsely diagnosed cases when MR images were reviewed retrospectively. The combination of T2-weighted and cholangiographic images using SSFSE is an accurate method for diagnosing pancreatcobiliary diseases

Is the 'Trondsen Discriminant Function' useful in patients referred for endoscopic retrograde cholangiopancreatography?

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Ainsworth, A P; Pless, T; Mortensen, M B

2003-01-01

BACKGROUND: Ideally, patients should only be referred to endoscopic retrograde cholangiopancreatography (ERCP) if therapy is indicated. The aim of this study was to evaluate whether or not the 'Trondsen Discriminant Function' (DF) could be used for selecting patients directly for ERCP. METHODS...

Is the 'Trondsen Discriminant Function' useful in patients referred for endoscopic retrograde cholangiopancreatography?

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Ainsworth, A P; Pless, T; Mortensen, M B

2003-01-01

BACKGROUND: Ideally, patients should only be referred to endoscopic retrograde cholangiopancreatography (ERCP) if therapy is indicated. The aim of this study was to evaluate whether or not the 'Trondsen Discriminant Function' (DF) could be used for selecting patients directly for ERCP. METHODS: T...

[Symptoms, diagnosis and treatment of pancreaticobiliary maljunction associated with congenital cystic dilatation of bile duct].

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Funabiki, T; Matsubara, T; Ochiai, M

1996-08-01

The concept of congenital biliary dilatation (CBD) was established by Alonso-Lej whose classification has been widely accepted and become a standard. Todani, Komi and several investigators then added additional subclassifications and/or made a proposal of new classification. The trias, abdominal pain, abdominal mass and jaundice, had been characteristically found in these cases, but recently asymptomatic cases are often found. Many reports have shown that the cases with cystic dilation of the biliary duct frequently associated with biliary carcinoma and pancreaticobiliary maljunction (PBM), an anomalous union of pancreatic duct with biliary tree since the Rabbit's first report. Whereas extracorporeal ultrasound and CT scan are minimally invasive diagnostic procedures for these cases, a direct cholangiography, ERCP and PTC are the diagnostic procedures that make a definite diagnosis for the appropriate treatment. Recently, endoscopic ultrasound (EUS), helical CT and magnetic resonance cholangiopan-creatography (MRCP) have drawn an attention since these methods are less invasive than those ever being used. In particular, MRCP will be suitable for the screening of preoperative examination. Whereas cystoduodenostomy used to be performed in the past for these cases, the resection of dilatted bule duct along with the diversion of bile from pancreatic juice should be performed to prevent biliary carcinoma. Cholecystectomy along with the resection of bile duct and the biliary diversion from pancreatic juice should also be performed for cases of PBM without CBD because mutagenicity of bile mixed with pancreatic juice and K-ras point mutation in noncancerous bile duct epithelium in cases of PBM without CBD were demonstrated.

Pancreaticobiliary maljunction and biliary cancer.

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Kamisawa, Terumi; Kuruma, Sawako; Tabata, Taku; Chiba, Kazuro; Iwasaki, Susumu; Koizumi, Satomi; Kurata, Masanao; Honda, Goro; Itoi, Takao

2015-03-01

Pancreaticobiliary maljunction (PBM) is a congenital malformation in which the pancreatic and bile ducts join anatomically outside the duodenal wall. Japanese clinical practice guidelines on how to deal with PBM were made in 2012, representing a world first. According to the 2013 revision to the diagnostic criteria for PBM, in addition to direct cholangiography, diagnosis can be made by magnetic resonance cholangiopancreatography (MRCP), 3-dimensional drip infusion cholangiography computed tomography, endoscopic ultrasonography (US), or multiplanar reconstruction images by multidetector row computed tomography. In PBM, the common channel is so long that sphincter action does not affect the pancreaticobiliary junction, and pancreatic juice frequently refluxes into the biliary tract. Persistence of refluxed pancreatic juice injures epithelium of the biliary tract and promotes cancer development, resulting in higher rates of carcinogenesis in the biliary tract. In a nationwide survey, biliary cancer was detected in 21.6% of adult patients with congenital biliary dilatation (bile duct cancer, 32.1% vs. gallbladder cancer, 62.3%) and in 42.4% of PBM patients without biliary dilatation (bile duct cancer, 7.3% vs. gallbladder cancer, 88.1%). Pathophysiological conditions due to pancreatobiliary reflux occur in patients with high confluence of pancreaticobiliary ducts, a common channel ≥6 mm long, and occlusion of communication during contraction of the sphincter. Once the diagnosis of PBM is established, immediate prophylactic surgery is recommended. However, the surgical strategy for PBM without biliary dilatation remains controversial. To detect PBM without biliary dilatation early, MRCP is recommended for patients showing gallbladder wall thickening on screening US under suspicion of PBM.

Spontaneous biliary peritonitis: Is bed side diagnosis possible?

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Vijai Datta Upadhyaya

2013-01-01

Full Text Available Background: Spontaneous biliary peritonitis is a rare cause of acute abdomen. In spontaneous biliary peritonitis there is perforation in the wall of the extra-hepatic or intra-hepatic duct occurs without any traumatic or iatrogenic injury and have been described more often in neonates. The symptoms may be acute or insidious delaying the diagnosis. Present manuscript deals with diagnosis and management of these cases. Materials and Methods: This is a prospective study and all patients of suspected biliary peritonitis presented during Dec 2010 to Feb 2012 were included in the study. After preliminary investigations in all patients abdominal paracentesis was done and in cases where intra-abdominal fluid bilirubin level was several fold higher than serum bilirubin level were subjected to exploratory laparotomy. Further investigation like T-tube cholangiogram and magnetic resonance cholangiopancreatography (MRCP was done to rule out choledochal cyst before leveling these cases as SPBD. Results: A total of 6 patients were included in present series commonest presenting symptom was progressive abdominal distension without signs of overt peritonitis followed by progressive jaundice, fever and abdominal pain. On exploration site of perforation was observed in 50% of cases and in 50% of cases bile duct was not dilated. Second surgery was not required in 34% of cases. There was no mortality or significant morbidity in our series. Conclusion: Spontaneous perforation of bile duct is rare disease and high index of suspicion is required for diagnosis. Simple bed side test can help in diagnosis but T tube cholangiogram or MRCP are must to rule out choledochal cyst.

Cytology evaluation for brushing in biliary and pancreatic stenosis during endoscopic cholangiopancreatography

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Ruiz, Mario H; Castano, Rodrigo; Alvarez, Oscar A; Velez, Alejandro; Munera, Veronica

2002-01-01

No surgical pathologic confirmation of malignant bile duct strictures is desirable for defining subsequent treatment and prognosis. Endoscopic retrograde cholangiopancreatography is frequently performed in patients suspected of having pancreaticobiliary obstruction, but there exists no standardized method or instruments for defining benign or malignant nature of obstructing lesions by ERCP. We prospectively evaluated the yields of endoscopic retrograde brush cytology for the diagnosis of malignant bile and pancreatic duct strictures. Fluoroscopically guided endobiliary brush cytology was performed during endoscopic retrograde cholangiopancreatography in 29 consecutive patients, 20 with malignant strictures and 9 with benign stricture. A single pathologist classified the results of these studies as positive, or negative for malignancy. The sensitivities of the procedure were 69%. Specificity proved excellent, 100%. Two major complications that occurred in the same patient were acute pancreatitis in a patient with chronic pancreatitis and bleeding from pancreatic duct. Both were managed medically and improved. This study indicates that endoscopic retrograde brush cytology alone may be sufficient in daily practice, to differentiate against benign and malignant biliary or pancreatic stenosis

MR imaging of primary sclerosing cholangitis - Additional value of diffusion-weighted imaging and ADC measurement

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Djokicc Kovac, Jelena [Center for Radiology and Magnetic Resonance Imaging, Clinical Center Serbia, Belgrade (Serbia)], e-mail: jelenadjokic2003@yahoo.co.uk; Maksimovic, Ruzica [Center for Radiology and Magnetic Resonance Imaging, Clinical Center Serbia, Belgrade (Serbia); Faculty of Medicine, Univ. of Belgrade, Belgrade (Serbia); Jesic, Rada [Clinic for Gastroenterohepatology, Clinical Center Serbia, Belgrade (Serbia); Faculty of Medicine, Univ. of Belgrade, Belgrade (Serbia); Stanisavljevic, Dejana [Inst. for Statistics, Faculty of Medicine, Univ. of Belgrade, Belgrade (Serbia); Kovac, Bojan [Military Medical Academy, Belgrade (Serbia)

2013-04-15

Background: Primary sclerosing cholangitis (PSC) is a cholestatic liver disease with chronic inflammation and progressive destruction of biliary tree. Magnetic resonance (MR) examination with diffusion-weighted imaging (DWI) allows analysis of morphological liver parenchymal changes and non-invasive assessment of liver fibrosis. Moreover, MR cholangiopancreatography (MRCP), as a part of standard MR protocol, provides insight into bile duct irregularities. Purpose: To evaluate MR and MRCP findings in patients with primary sclerosing cholangitis and to determine the value of DWI in the assessment of liver fibrosis. Material and Methods: The following MR findings were reviewed in 38 patients: abnormalities in liver parenchyma signal intensity, changes in liver morphology, lymphadenopathy, signs of portal hypertension, and irregularities of intra- and extrahepatic bile ducts. Apparent diffusion coefficient (ADC) was calculated for six locations in the liver for b = 800 s/mm{sup 2}. Results: T2-weighted hyperintensity was seen as peripheral wedge-shaped areas in 42.1% and as periportal edema in 28.9% of patients. Increased enhancement of liver parenchyma on arterial-phase imaging was observed in six (15.8%) patients. Caudate lobe hypertrophy was present in 10 (26.3%), while spherical liver shape was noted in 7.9% of patients. Liver cirrhosis was seen in 34.2% of patients; the most common pattern was micronodular cirrhosis (61.5%). Other findings included lymphadenopathy (28.9%), signs of portal hypertension (36.7%), and bile duct irregularities (78.9%). The mean ADCs (x10{sup -3} mm{sup 2}/s) were significantly different at stage I vs. stages III and IV, and stage II vs. stage IV. No significant difference was found between stages II and III. For prediction of stage {>=}II and stage {>=}III, areas under receiver-operating characteristic curves were 0.891 and 0.887, respectively. Conclusion: MR with MRCP is a necessary diagnostic procedure for diagnosis of PSC and

Diclofenac Is Associated With a Reduced Incidence of Post–Endoscopic Retrograde Cholangiopancreatography Pancreatitis

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Leerhøy, Bonna; Nordholm-Carstensen, Andreas; Novovic, Srdan

2014-01-01

OBJECTIVE: The aim of this study was to assess the clinical effect of diclofenac administered as a single dose for the prevention of postprocedure pancreatitis in a consecutive series of patients who had undergone endoscopic retrograde cholangiopancreatography (ERCP). METHODS: Patients with a nat......OBJECTIVE: The aim of this study was to assess the clinical effect of diclofenac administered as a single dose for the prevention of postprocedure pancreatitis in a consecutive series of patients who had undergone endoscopic retrograde cholangiopancreatography (ERCP). METHODS: Patients...... with a native papilla Vateri subjected to ERCP during 2010 (control group, n = 218) and 2012 (diclofenac group, n = 182) were included. Patients with a history of chronic pancreatitis or recent acute pancreatitis were excluded. From January 2012, a rectal suppository containing 100 mg of diclofenac...... patients in the diclofenac group (P = 0.002). Moderate to severe pancreatitis occurred in 22 (10.1%) of the 218 patients in the control group versus 8 (4.4%) of the 182 patients in the diclofenac group (P = 0.036). CONCLUSIONS: This controlled cohort study suggests that the implementation of a single dose...

Mucinous cystic neoplasms and serous cystadenomas arising in the body-tail of the pancreas: MR imaging characterization

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Manfredi, Riccardo; Ventriglia, Anna; Mehrabi, Sara; Boninsegna, Enrico; Pozzi Mucelli, Roberto [University of Verona, Department of Radiology, Verona (Italy); Mantovani, William [Provincial Health Services, Department of Public Health and Prevention, Trento (Italy); Zamboni, Giuseppe [University of Verona, Department of Pathology, Verona (Italy); Salvia, Roberto [University of Verona, Department of Surgery, Verona (Italy)

2015-04-01

To identify magnetic resonance (MR)/MR cholangiopancreatography (MRCP) imaging signs helpful in the differential diagnosis between serous cystadenomas (SCAs) and mucinous cystic neoplasms (MCNs), arising from the body/tail of the pancreas. This retrospective study had institutional review board approval and informed consent was waived. Fifty-three patients with non-communicating cystic pancreatic neoplasm of the body/tail, undergoing MR/MRCP, were included. Qualitative image analysis assessed the macroscopic pattern, number of cysts, presence of central scar, contrast enhancement of peripheral wall, and mural nodules. Quantitative analysis assessed the maximum diameter of the neoplasm, thickness of the peripheral wall, and calibre of the upstream main pancreatic duct. Histopathology results revealed that 27/53 (51 %) were SCAs, 26/53 (49 %) were MCNs. Microcystic pattern was observed in 88.2 % of SCAs and 11.8 % of MCNs; macrocystic pattern was observed in 90.5 % of MCNs and 9.5 % of SCAs (p < 0.0001). Central scar was detected in 29.6 % of SCAs and no MCNs (p = 0.003). Contrast enhancement of the peripheral wall was evident in 99.5 % of MCNs and 11.5 % of SCAs (p < 0.0001); mural nodules were depicted in 94.1 % of MCNs and 5.9 % of SCAs (p < 0.0001). Median maximum diameter was 54 mm for MCNs, 32 mm for SCAs (p = 0.001); median wall thickness was 4 mm for MCNs, 2 mm for SCAs (p < 0.0001). Macrocystic pattern, enhancement of a peripheral wall and mural nodules are suggestive of MCNs; whereas microcystic pattern, lack of peripheral wall and central scar are suggestive of SCAs. (orig.)

An unfortunate case of acquired hemochromatosis: a case report review of the clinical presentation, diagnosis, management, and prognosis

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Tariq A

2016-12-01

Full Text Available Anam Tariq,1 Kevin Westra,2 Arben Santo3 1Department of Internal Medicine, Pinnacle Health Internal Medicine, 2Department of Gastroenterology, Harrisburg Gastroenterology, Harrisburg, PA, 3Department of Pathology, Virginia College of Osteopathic Medicine-Virginia Tech, Blacksburg, VA, USA Background: While blood transfusions are commonly used for prophylaxis and treatment for acute chest syndromes and strokes in sickle cell patients, accumulation of excess iron resulting in secondary hemochromatosis remains a rare disease. Chelation is the mainstay for preventing and treating iron overload to deter potential end-organ damages; it is rare when therapy fails. Case report: A 52-year-old African American woman with chronic anemia secondary to sickle cell anemia and history of multiple blood transfusions presented with elevated serum ferritin (8000 ng/mL and bilirubin (16.8 mg/dL. She had no previous personal or family history of liver disease. A magnetic resonance cholangiopancreatography (MRCP and a liver biopsy confirmed the secondary hemochromatosis with marked fibrosis and 4+ iron deposits, but since she was therapeutically on deferasirox, her treatment regimen involved only closer monitoring. Her hemochromatosis led to readmission within a year for rapid progression of cardiac and hepatic failure. Conclusion: Since chronically transfused sickle cell patients are at a significantly higher risk of mortality due to the secondary hemochromatosis and end-stage organ damage, knowledge of prophylactic iron chelation is important. Minimizing unnecessary transfusions should be strongly emphasized to reduce the sequelae as iron burden remains a threat. The effectiveness of iron-chelating therapy is best monitored via periodic magnetic resonance imaging, liver transaminases, bilirubin, creatinine, ferritin, and cardiac function tests. Despite the prophylactic treatment and quarterly blood work, in this case the initial presentation did not correlate with

Efficacy and safety of endoscopic retrograde cholangiopancreatography in aged and elderly geriatric patients to treat acute cholecystitis

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GAO Feng

2013-03-01

Full Text Available ObjectiveTo retrospectively evaluate the therapeutic efficacy and safety of endoscopic retrograde cholangiopancreatography (ERCP for treating acute cholecystitis in geriatric patients 75 years and older in age. MethodsThe clinical records of our institute were searched to identify aged (75-84 years old and elderly (85 years and older patients who underwent ERCP between January 2008 and December 2012 for new or long-term cholecystitis. The cholecystitis was clinically characterized as acute attack time(s of one to five days and diagnosis was confirmed by imaging analysis (including abdominal ultrasound, computed tomography, and/or magnetic resonance cholangiopancreatography. All surgeries were carried out with the endoscopic nasogallbladder drainage (ENGBD procedure. Postoperative symptoms (such as abdominal pain and fever and clinical findings (such as C-reactive protein (CRP level, imaging findings, and bile drainage volume and consistency were recorded, along with follow-up data of outcome and symptomology, for summary evaluation. ResultsA total 24 patients, including 13 men and 11 women between the ages of 75 and 88 (mean: 81.00±3.23 years, underwent ERCP examination. The cases included general cholecystitis (75.0%, n=18 and acalculous cholecystitis (25.0%, n=6. In addition, 13 (54.2% cases had biliary stones and two (8.3% cases had bile pancreatitis. The ENGBD tube was successfully inserted into the gallbladder in all cases. Twenty-one (87.5% patients experienced relief of abdominal pain and fever within 24 h of the surgery. CRP level decreased to normal for all (100% patients within six days of the surgery. Two (8.3% patients experienced hyperamylasemia within three days of the surgery, and both cases resolved prior to hospital release. There were no cases of ERCP-related hemorrhage, perforation, pancreatitis, or death. Follow-up time ranged from three to 12 months, during which 23 (95.8% patients showed long-term remission. The presence

Recurrent Acute Pancreatitis as A Manifestation of Sphincter of Oddi Dysfunction

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Ira Laurentika

2016-04-01

Full Text Available Recurrent acute pancreatitis (RAP is defined as two or more occurance of acute pancreatitis with no evidence of underlying chronic pancreatitis. Prevalence of RAP varied from 10-30%. One of the postulated mechanism of this condition is sphincter of Oddi dysfunction (SOD which is a clinical biliary pain syndrome or acute pancreatitis (AP due to pancreatobiliary obstruction at the level of sphincter of Oddi. We reported a 29-year-old female patient who came to Cipto Mangunkusomo Hospital regarding upper quadrant abdominal pain with previously well documented history of AP in the last six months before admission. Laboratory findings showed elevated pancreatic enzyme level which was consistent with AP. The patient underwent magnetic resonance cholangio-pancreatography (MRCP and endoscopic ultrasound (EUS examination and both of the results showed dilatation of pancreatic duct which suggested SOD. Due to the lack of further diagnostic modality, manometry was not performed on this patient. However, after excluding other possible etiology of SOD, the patient underwent endoscopic retrograde cholangio-pamcreatograhy (ERCP and sphincterotomy was performed. The signs and symptoms of AP was relieved after sphincterotomy and not yet recurred.

Diagnosis and treatment with endoscopic retrograde cholangiopancreatography

International Nuclear Information System (INIS)

Soendenaa, K.; Horn, A.; Viste, A.

1994-01-01

Endoscopic retrograde cholangiopancreatography (ERCP) was carried out for the first time in 1968. Five years later endoscopic sphincterotomy was performed. Since then both modalities have become established as necessary adjuncts in the diagnosis and treatment of patients with pathology in the bile duct or pancreas. The main indication is common bile duct stone, and as a consequence of this treatment fewer patients are now treated surgically. Patients with malignant bile duct obstruction can be given reasonable palliation of both jaundice and pruritus and therefore improved quality of life. Some reports indicate that endoscopic drainage may be useful for pancreatic stenosis. Complications are few, but vigilance and prompt treatment is necessary to keep morbidity at a minimum. Follow-up after several years shows that sphincterotomy is successful also in the long term. The authors discuss the present diagnostic and therapeutic situation. 31 refs., 2 tabs

MRI system scoring for differentiation of malignant versus benign stricture of the common bile duct

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Savastano S

2016-11-01

Full Text Available The purpose of this study was to evaluate the ability of magnetic resonance imaging (MRI to differentiate between malignant and benign strictures of the common bile duct by using a scoring system. MRI scans of 34 patients with indeterminate biliary stricture on prior imaging were reviewed; non-enhanced MRI, magnetic resonance cholangiopancreatography (MRCP, diffusion weighted imaging, and contrast-enhanced MRIs were considered for analysis. Ten radiologic findings were significant for malignancy: luminal irregularity, post-contrast conspicuity, high signal intensity on diffusion weighted MRI, luminal stenosis asymmetry, T2-weighted MRI signal intensity, indistinct outer border, abrupt stenosis, bile duct dilatation ≥ 12.5 mm, stenosis length ≥ 10.5 mm, and wall thickness ≥ 4.5 mm. Since none of these findings was pathognomonic for malignancy, a simple system scoring based on statistically significant findings was developed, where each of the above findings counts for one point. A score of 6 or higher was found only in patients with a malignant stricture of the common bile duct; 70% of patients with a benign stenosis had a score of 1, or 2, and all patients with benign lesions had scores of less than 5. This MRI scoring system can assist in the differential diagnosis of common bile duct stricture with high accuracy; to be widely applicable, the MRI score needs to be validated in a prospective patient population.

MR elastography in primary sclerosing cholangitis: correlating liver stiffness with bile duct strictures and parenchymal changes.

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Bookwalter, Candice A; Venkatesh, Sudhakar K; Eaton, John E; Smyrk, Thomas D; Ehman, Richard L

2018-04-07

To determine correlation of liver stiffness measured by MR Elastography (MRE) with biliary abnormalities on MR Cholangiopancreatography (MRCP) and MRI parenchymal features in patients with primary sclerosing cholangitis (PSC). Fifty-five patients with PSC who underwent MRI of the liver with MRCP and MRE were retrospectively evaluated. Two board-certified abdominal radiologists in agreement reviewed the MRI, MRCP, and MRE images. The biliary tree was evaluated for stricture, dilatation, wall enhancement, and thickening at segmental duct, right main duct, left main duct, and common bile duct levels. Liver parenchyma features including signal intensity on T2W and DWI, and hyperenhancement in arterial, portal venous, and delayed phase were evaluated in nine Couinaud liver segments. Atrophy or hypertrophy of segments, cirrhotic morphology, varices, and splenomegaly were scored as present or absent. Regions of interest were placed in each of the nine segments on stiffness maps wherever available and liver stiffness (LS) was recorded. Mean segmental LS, right lobar (V-VIII), left lobar (I-III, and IVA, IVB), and global LS (average of all segments) were calculated. Spearman rank correlation analysis was performed for significant correlation. Features with significant correlation were then analyzed for significant differences in mean LS. Multiple regression analysis of MRI and MRCP features was performed for significant correlation with elevated LS. A total of 439/495 segments were evaluated and 56 segments not included in MRE slices were excluded for correlation analysis. Mean segmental LS correlated with the presence of strictures (r = 0.18, p duct strictures. Segments with increased LS show T2 hyperintensity, DWI hyperintensity, and post-contrast hyperenhancement. Global liver stiffness shows a moderate correlation with number of segmental strictures and significantly correlates with spleen stiffness, splenomegaly, and varices.

Recurrent acute pancreatitis: an approach to diagnosis and management.

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Kedia, Saurabh; Dhingra, Rajan; Garg, Pramod Kumar

2013-01-01

Recurrent acute pancreatitis (RAP) is defined as more than two attacks of acute pancreatitis (AP) without any evidence of underlying chronic pancreatitis (CP). As the known causes of AP are generally taken care of, RAP usually occurs in the idiopathic group, which forms 20%-25% of cases of AP. The causes of idiopathic RAP (IRAP) can be mechanical, toxic-metabolic, anatomical, or miscellaneous. Microlithiasis commonly reported from the West is not a common cause of IRAP among Indian patients. Pancreas divisum (PD) is now believed as a cofactor, the main factor being associated genetic mutations. The role of Sphincter of Oddi dysfunction (SOD) as a cause of IRAP remains controversial. Malignancy should be ruled out in any patient with IRAP > 50 years of age. Early CP can present initially as RAP. The work-up of patients with IRAP includes a detailed history and investigations. Primary investigations include liver function tests (LFT), serum calcium and triglyceride, abdominal ultrasonography (USG) and contrast-ehhanced computed tomography (CECT) abdomen. Endoscopic ultrasound (EUS), magnetic resonance cholangiopancreatography (MRCP) and possibly endoscopic retrograde cholangiopancreatography (ERCP) are indicated in the secondary phase if the work-up is negative after the primary investigations. EUS is advised usually 6-8 weeks after an acute episode. Treatment of patients with IRAP is aimed at the specific aetiology. In general, empirical cholecystectomy should be discouraged with the availability and widespread use of EUS. Endoscopic sphincterotomy is advised if there is strong suspicion of SOD. Minor papilla sphincterotomy should be carried out in those with PD but with limited expectations. Regular follow-up of patients with IRAP is necessary because most patients are likely to develop CP in due course.

Worsening cholestasis and possible cefuroxime-induced liver injury following "successful" therapeutic endoscopic retrograde cholangiopancreatography for a distal common bile duct stone: a case report.

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Niriella, Madunil Anuk; Kumarasena, Ravindu Sujeewa; Dassanayake, Anuradha Supun; Pathirana, Aloka; de Silva Hewavisenthi, Janaki; de Silva, Hithanadura Janaka

2016-12-21

Cefuroxime very rarely causes drug-induced liver injury. We present a case of a patient with paradoxical worsening of jaundice caused by cefuroxime-induced cholestasis following therapeutic endoscopic retrograde cholangiopancreatography for a distal common bile duct stone. A 51-year-old, previously healthy Sri Lankan man presented to our hospital with obstructive jaundice caused by a distal common bile duct stone. Endoscopic retrograde cholangiopancreatography with stone extraction, common bile duct clearance, and stenting failed to improve the cholestasis, with paradoxical worsening of his jaundice. A liver biopsy revealed features of drug-induced intrahepatic cholestasis. Although his case was complicated by an episode of cholangitis, the patient made a complete recovery in 4 months with supportive treatment and withdrawal of the offending drug. This case highlights a very rare drug-induced liver injury caused by cefuroxime as well as our approach to treating a patient with paradoxical worsening of jaundice after therapeutic endoscopic retrograde cholangiopancreatography.

Diagnostic and Prevention Approach in Post Endoscopic Retrograde Cholangiopancreatography Pancreatitis

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Stella Ilone

2016-12-01

Full Text Available Obstructive jaundice (icterus was an emergency situation in gastroenterology. Endoscopic retrograde cholangiopancreatography (ERCP was a nonsurgical approach to release obstruction, mostly in common bile duct. Nowadays, this procedure was become frequently used in daily practice, but several complications also emerging. One of the severe complication was Post-ERCP Pancreatitis (PEP. Since it has a high mortality and morbidity, and also reduce patient quality of life, several approaches have been developed to reduce its incidence. In general, approaches consist of patient identification, efficient procedure, until pharmacological agent prevention. Although there were still contradiction among these, careful approach should be considered for each patients for a better outcomes.

Revision of anastomotic stenosis after pancreatic head resection for chronic pancreatitis: is it futile?

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Morgan, Katherine A; Fontenot, Bennett B; Harvey, Norman R; Adams, David B

2010-01-01

Background: Because survival after pancreaticoduodenectomy for cancer is limited, it is difficult to assess longterm pancreaticojejunal anastomotic patency. However, in patients with benign disease, pancreaticojejunal anastomotic stenosis may become problematic. What happens when pancreaticojejunal anastomosis revision is undertaken? Methods: Patients undergoing pancreatic anastomotic revision after pancreatic head resection for benign disease between 1997 and 2007 at the Medical University of South Carolina were identified. A retrospective chart review and analysis were undertaken with the approval of the Institutional Review Board for the Evaluation of Human Subjects. Longterm follow-up was obtained by patient survey at a clinic visit or by telephone. Results: During the study period, 237 patients underwent pancreatic head resection. Of these, 27 patients (17 women; median age 42 years) underwent revision of pancreaticojejunal anastomosis. Six patients (22%) had a pancreatic leak or abscess at the time of the index pancreatic head resection. The indication for revision of anastomosis was intractable pain. All patients underwent preoperative magnetic resonance cholangiopancreatography (MRCP), which indicated anastomotic stricture in 18 patients (63%). Nine other patients underwent exploration based on clinical suspicion caused by recurrent pancreatitis and stenosis was confirmed at the time of surgery. Six patients (22%) had perioperative complications after revision. The median length of stay was 12 days. There were no perioperative deaths; however, late mortality occurred in four patients (15%). Six of 23 survivors (26%) at the time of follow-up (median 56 months) reported longterm pain relief. Conclusions: Stricture of the pancreaticojejunal anastomosis after pancreatic head resection presents with recurrent pancreatitis and pancreatic pain. MRCP has good specificity in the diagnosis of anastomotic obstruction, but lacks sensitivity. Pancreaticojejunal revision

Computed tomography, ultrasonography, and endoscopic retrograde cholangiopancreatography in the diagnosis of pancreatic disease

International Nuclear Information System (INIS)

Foley, W.D.; Stewart, E.T.; Lawson, T.L.; Maher, L.; Unger, G.F.; Geenan, J.; Loguidice, J.

1980-01-01

A prospective study was performed comparing the sensitivity of computed tomography, ultrasonography, and endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of pancreatic disease. Forty patients with suspected pancreatic carcinoma, acute recurrent or chronic pancreatitis, and/or jaundice were studied. CT was the most sensitive study in evaluation of pancreatitis. ERCP was most accurate in evaluation of pancreatic malignancy. Ultrasonography was the least sensitive method in detecting pancreatic disease and dilatation of the extrahepatic biliary ducts. (orig.) [de

Graduates of different UK medical schools show substantial differences in performance on MRCP(UK Part 1, Part 2 and PACES examinations

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Mollon Jennifer

2008-02-01

Full Text Available Abstract Background The UK General Medical Council has emphasized the lack of evidence on whether graduates from different UK medical schools perform differently in their clinical careers. Here we assess the performance of UK graduates who have taken MRCP(UK Part 1 and Part 2, which are multiple-choice assessments, and PACES, an assessment using real and simulated patients of clinical examination skills and communication skills, and we explore the reasons for the differences between medical schools. Method We perform a retrospective analysis of the performance of 5827 doctors graduating in UK medical schools taking the Part 1, Part 2 or PACES for the first time between 2003/2 and 2005/3, and 22453 candidates taking Part 1 from 1989/1 to 2005/3. Results Graduates of UK medical schools performed differently in the MRCP(UK examination between 2003/2 and 2005/3. Part 1 and 2 performance of Oxford, Cambridge and Newcastle-upon-Tyne graduates was significantly better than average, and the performance of Liverpool, Dundee, Belfast and Aberdeen graduates was significantly worse than average. In the PACES (clinical examination, Oxford graduates performed significantly above average, and Dundee, Liverpool and London graduates significantly below average. About 60% of medical school variance was explained by differences in pre-admission qualifications, although the remaining variance was still significant, with graduates from Leicester, Oxford, Birmingham, Newcastle-upon-Tyne and London overperforming at Part 1, and graduates from Southampton, Dundee, Aberdeen, Liverpool and Belfast underperforming relative to pre-admission qualifications. The ranking of schools at Part 1 in 2003/2 to 2005/3 correlated 0.723, 0.654, 0.618 and 0.493 with performance in 1999–2001, 1996–1998, 1993–1995 and 1989–1992, respectively. Conclusion Candidates from different UK medical schools perform differently in all three parts of the MRCP(UK examination, with the

Duodenal perforation: after endoscopic retrograde cholangiopancreatography: when to operate?

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Garcia Navarrete, Aldhem Francisco

2014-01-01

The mainly surgical management of duodenal perforation as the iatrogenicity of endoscopic retrograde cholangiopancreatography (ERCP) is defined and protocolized through the exhaustive review of the most conclusive literature available on the subject. Bibliography on the management of post-ERCP duodenal perforation is reviewed in scientific databases, textbooks, publications of medical journals, MD Consult and Medline. A total of 60 bibliographical citations were reviewed; succeeding in defining the protocol on the management of this type of complications, thanks to the appropriate selection of the most conclusive citations and the greatest consensus on the subject. A total of 60 bibliographical citations were reviewed; succeeding in defining the protocol on the management of this type of complications, based on the appropriate selection of the most conclusive citations and the greatest consensus on the subject [es

Antioxidant drugs to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis: What does evidence suggest?

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Fuentes-Orozco, Clotilde; Dávalos-Cobián, Carlos; García-Correa, Jesús; Ambriz-González, Gabriela; Macías-Amezcua, Michel Dassaejv; García-Rentería, Jesús; Rendón-Félix, Jorge; Chávez-Tostado, Mariana; Cuesta-Márquez, Lizbeth Araceli; Alvarez-Villaseñor, Andrea Socorro; Cortés-Flores, Ana Olivia; González-Ojeda, Alejandro

2015-06-07

To determine whether or not the use of antioxidant supplementation aids in the prevention of post- endoscopic retrograde cholangiopancreatography pancreatitis. A systematic review of randomized controlled trials (RCTs) was made to evaluate the preventive effect of prophylactic antioxidant supplementation in post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP). The inclusion criteria included: acute post-endoscopic retrograde cholangiopancreatography pancreatitis in adults; randomized clinical trials with the use of any antioxidant as an intervention compared with placebo, to reduce PEP. The outcome measure was the incidence and severity of PEP. Twelve RCTs involving 3110 patients since 1999 were included. The antioxidants used were selenite, β-carotene, and pentoxifylline (each one in one trial), N-acetylcysteine (NAC) in three trials, and allopurinol in six trials. The group of patients treated with NAC received different doses; either oral or intravenous, and allopurinol-treated patients received five different oral doses in two different administration periods. The results are expressed with raw numbers, proportions, as well as mean and standard deviations. The incidence of pancreatitis between groups was analyzed with Pearson's χ(2) test or Fisher's exact test (F). The main outcome is expressed as relative risks and 95%CI. The incidence of pancreatitis in all antioxidant treatment groups was 8.6%, whereas it was 9.7% in the control group. The antioxidants used were selenite, β-carotene, and pentoxifylline (each one in one trial), NAC in three trials, and allopurinol in six trials. In allopurinol trials, three different dosifications were used; two trials reported a low dosage (of less than 400 mg), two trials reported a moderate dose (600 mg) and the remaining two employed higher doses (more than 900 mg). Supplementation was not associated with a significant reduction in the incidence of PEP [relative risk (RR) = 0.93; 95%CI: 0.82-1.06; P

Research advances in the prevention and treatment of pancreatitis after endoscopic retrograde cholangiopancreatography

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ZHANG Weifeng

2018-03-01

Full Text Available Endoscopic retrograde cholangiopancreatography (ERCP is an important technique for the diagnosis and treatment of biliary and pancreatic diseases and post-ERCP pancreatitis (PEP is the most common complication of ERCP. Since the birth of ERCP, the prevention and treatment of PEP has become the focus of international research. In recent years, much progress has been made in the aspects of risk factors, pharmacological prevention, and prophylactic stent implantation in the pancreatic duct. Since these research findings are not consistent, further clinical studies are needed to demonstrate such findings.

Thyrotoxicosis and Choledocholithiasis Masquerading as Thyroid Storm

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Christian L. Horn

2017-01-01

Full Text Available A 26-year-old female, thirteen months postpartum, presented to the emergency department for four weeks of epigastric abdominal pain, pruritus, new onset jaundice, and 11.3 kgs (25 lbs unintentional weight loss. On examination, she was afebrile, tachycardic, alert, and oriented and had jaundice with scleral icterus. Labs were significant for undetectable TSH, FT4 that was too high to measure, and elevated total bilirubin, direct bilirubin, alkaline phosphatase, and transaminases. Abdominal ultrasound revealed cholelithiasis without biliary ductal dilation. Treatment for presumed thyroid storm was initiated. Further work-up with magnetic resonance cholangiopancreatography (MRCP revealed an obstructing cholelith within the distal common bile duct. With the presence of choledocholithiasis explaining the jaundice and abdominal pain, plus the absence of CNS alterations, the diagnosis of thyroid storm was revised to thyrotoxicosis complicated by choledocholithiasis. Endoscopic retrograde cholangiopancreatogram (ERCP with sphincterotomy was performed to alleviate the biliary obstruction, with prompt symptomatic improvement. Thyroid storm is a rare manifestation of hyperthyroidism with a high rate of morbidity and mortality. The diagnosis of thyroid storm is based on clinical examination, and abnormal thyroid function tests do not correlate with disease severity. Knowledge of the many manifestations of thyroid storm will facilitate a quick and accurate diagnosis and treatment.

Frequency and contributing factors for acute pancreatitis after endoscopic retrograde cholangiopancreatography in patients with obstructive jaundice

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Zubair, M.; Zaidi, A.R.; Hyder, A.

2017-01-01

To evaluate the frequency and contributing factors for acute pancreatitis after endoscopic retrograde cholangio-pancreatography in patients with obstructive jaundice. Study Design: Descriptive case series. Place and Duration of Study: A descriptive case series conducted at department of Gastroenterology, Shaikh Zayed Hospital, Lahore in the period of six months. Material and Methods: Two hundred and thirty patients diagnosed as having obstructive jaundice and undergoing ERCP who fulfilled the inclusion criteria were included in the study from the outpatient and indoor department of Gastroenterology-Hepatology Shaikh Zayed Hospital Lahore. Informed consent was taken. After the selection of the cases, patients were evaluated for the presence or absence of contributing factors like age, gender, cannulation attempts, cannulation time, percutaneous papillotomy, pancreatic duct contrast injection and previous history of post ERCP pancreatitis. Data was analysed by using the statistical software for social sciences (SPSS) version 15. Results: In our study, mean age was 44 +- 14.12 years. Out of 230 patients 42.17% (n=97) were male and 57.83% (n=133) were females. Frequency of acute pancreatitis after ERCP in patients with obstructive jaundice was 4.78% (n=11) while 95.22% (n=219) had no findings of acute pancreatitis after ERCP. Frequency of factors for acute pancreatitis after endoscopic retrograde cholangiopancreatography in patients with obstructive jaundice was recorded which shows that out of 11 cases, 45.45% (n=5) were females, 36.36% (n=4) had previous history of Post ERCP Pancreatitis, 27.27% (n=3) had >5 attempts of cannulation, 36.36% (n=4) had >5 minute time for cannulation, 54.55% (n=6) had pre-cut papillotomy while 63.64% (n=7) had pancreatic duct contrast injection. Conclusion: We concluded that frequency of acute pancreatitis after endoscopic retrograde cholangiopancreatography in patients with obstructive jaundice was found not very high in our practice

Increased fat in pancreas not associated with risk of pancreatitis post-endoscopic retrograde cholangiopancreatography

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Pokhrel B

2014-06-01

Full Text Available Bhupesh Pokhrel,1 Eun Kwang Choi,1 Omer Khalid,2 Kumar Sandrasegaran,3 Evan L Fogel,1 Lee McHenry,1 Stuart Sherman,1 James Watkins,1 Gregory A Cote,1 Henry A Pitt,4 Nicholas J Zyromski,4 Beth Juliar,1 Glen A Lehman11Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 2Department of Gastroenterology, St Louis University School of Medicine, St Louis, MO, 3Department of Radiology, 4Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USABackground: A preliminary study has shown increased pancreatic fat in patients with idiopathic pancreatitis and sphincter of Oddi dysfunction. In this study, we aimed to determine if an increased quantity of pancreatic fat is an independent risk factor for pancreatitis post-endoscopic retrograde cholangiopancreatography (ERCP.Methods: In this case control study, we retrospectively reviewed a local radiological and ERCP database to identify patients who had had abdominal magnetic resonance imaging (MRI followed by ERCP no more than 60 days later between September 2003 and January 2011. Percentage of fat was determined by recording signal intensity in the in-phase (Sin and out-of-phase (Sout T1-weighted gradient sequences, and calculation of the fat fraction as (Sin - Sout/(Sin × 2 by an abdominal radiologist blinded to clinical history. Controls matched for age, gender, and other pancreatobiliary disease were selected from a group with no post-ERCP pancreatitis (before fat content of the pancreas was analyzed.Results: Forty-seven patients were enrolled. Compared with controls, subjects with post-ERCP pancreatitis were similar in terms of age (41.4 years versus 41.1 years, gender (21.2% versus 20.2% males, pancreatobiliary disease characteristics, and most ERCP techniques. Measurements of pancreatic head, body, and tail fat and body mass index were similar in patients and controls.Conclusion: Increased pancreatic fat on MRI criteria is not an independent

Bedside Endoscopic Retrograde Cholangiopancreatography Using Portable X-Ray in Acute Severe Cholangitis

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Rushikesh Shah

2018-01-01

Full Text Available Patients with acute cholangitis require emergent biliary decompression. Those who are hemodynamically unstable on vasopressor support and mechanical ventilation are too critically ill to move outside of the intensive care unit. This prohibits performing Endoscopic Retrograde Cholangiopancreatography (ERCP in the endoscopy unit. Fluoroscopic guidance is required to confirm deep biliary cannulation during ERCP. There are a few reported cases of bedside ERCP using portable C-arm fluoroscopy unit or ultrasound guided cannulation. We present a unique case of life-saving emergent bedside ERCP in a severely ill patient with cholangitis and septic shock, using simple portable X-ray to confirm biliary cannulation.

Magnetic resonance (MR) in the diagnosis of pancreatic disease

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Anacker, H.; Rupp, N.; Reiser, M.; Technische Univ. Muenchen

1984-01-01

New methods of examination are measured in terms of the efficiency of their predecessors. The introduction of endoscopic retrograde cholangiopancreatography (ERCP) and computerised tomography (CT) constituted a turning point in the diagnosis of pancreatic disease. In this incipient stages as a clinical diagnostic method, the question is raised whether or not there is evidence that magnetic resonance (MR) can supplement, improve upon or replace the customary methods. It must, however, be taken into account that the technical development of MR is still in progress and that clinical experience with MR in the diagnosis of pancreatic disease, as in other areas, is still insufficient. At this point it is only possible to survey the trends. (orig.)

Diagnosis of choledocholithiasis and therapeutic results with endoscopic retrograde cholangiopancreatography

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Ramos Pachon, Carlos; Gonzalez Cansino, Juan; Fernandez Maderos, Irma

2009-01-01

A descriptive, prospective study was carried out on 451 patients that were attended for endoscopic retrograde cholangiopancreatography at CIMEQ's Hospital from January 2004-March 2006. The sample was constituted by 353 patients with choledocholithiasis suspicion. The information was search in the reports of ERCP and the variables were analyzed with the objective of evaluating the diagnostic possibilities and the therapy for choledocholithiasis by ERCP. Choledocholithiasis was detected in 1/4 of the patients with indication of ERCP, and was more frequent in patients of the female sex and in patients older than 40 years. The jaundice was the main clinical condition that motivated the ERCP in the patients with choledocholithiasis. The diagnostic effectiveness of the alkaline phosphatase and the ultrasound was not high. The treatment of the choledocholithiasis by means of ERCP showed good results and low morbidity

Activities in a social networking-based discussion group by endoscopic retrograde cholangiopancreatography doctors.

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Kang, Xiaoyu; Zhao, Lina; Liu, Na; Wang, Xiangping; Zhang, Rongchun; Liu, Zhiguo; Liang, Shuhui; Yao, Shaowei; Tao, Qin; Jia, Hui; Pan, Yanglin; Guo, Xuegang

2017-10-01

Online social networking is increasingly being used among medical practitioners. However, few studies have evaluated its use in therapeutic endoscopy. Here, we aimed to analyze the shared topics and activities of a group of endoscopic retrograde cholangiopancreatography (ERCP) doctors in a social networking-based endoscopic retrograde cholangiopancreatography discussion group (EDG). Six ERCP trainers working in Xijing Hospital and 48 graduated endoscopists who had finished ERCP training in the same hospital were invited to join in EDG. All group members were informed not to divulge any private information of patients when using EDG. The activities of group members on EDG were retrospectively extracted. The individual data of the graduated endoscopists were collected by a questionnaire. From June 2014 to May 2015, 6924 messages were posted on EDG, half of which were ERCP related. In total, 214 ERCP-related topics were shared, which could be categorized into three types: sharing experience/cases (52.3%), asking questions (38.3%), and sharing literatures/advances (9.3%). Among the 48 graduated endoscopists, 21 had a low case volume of less than 50 per year and 27 had a high volume case volume of 50 or more. High-volume graduated endoscopists posted more ERCP-related messages (P=0.008) and shared more discussion topics (P=0.003) compared with low-volume graduated endoscopists. A survey showed that EDG was useful for graduated endoscopists in ERCP performance and management of post-ERCP complications, etc. A wide range of ERCP-related topics were shared on the social networking-based EDG. The ERCP-related behaviors on EDG were more active in graduated endoscopists with an ERCP case volume of more than 50 per year.

Retrograde cholangiopancreatography in the diagnosis of biliary and pancreatic duct diseases

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Vasil'ev, Yu.D.; Sedletskaya, T.N.

1980-01-01

Results of retrograde cannulation with the aid of flexible fibroduodenoscopes with subsequent introduction of a contrast substance into biliary and pancreatic ducts are presented. The investigation is carried out on 120 patients with different diseases of hepatopancreatoduodenal zone. The standard technique of X-ray examination has been applied permitting to obtain the most exhaustive information. Using retrograde cholangiopancreatography revealed have been choledocholithiasis, deformation of biliary ducts after surgical intervention, pancreatic cyst, tumor of the main pancreatic duct etc. Results of investigation of biliary and pancreatic ducts using retrograde cannulation are reaffirmed with the data of operations on biliary tract in 72 patients. Intraoperational cholangiography has been carried out on 36 of them during operation. An attempt to cannulate big duodenal papilla in 12 patients proved to be ineffective. No complications have been observed during examination

Endoscopic retrograde cholangiopancreatography, endoscopic esphinterotomy and laparoscopic cholecystectomy in a patient with choledocolitiasis and cholelitiasis

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Riveron Quevedo, Kelly; Irsula Ballaga, Vladimir; Gonzalez Ulloa, Lianne; Deborah LLorca, Armando

2012-01-01

The case report of a 30 year-old presumably healthy patient, who attended the Gastroenterology Department from 'Dr Juan Bruno Zayas Alfonso' Teaching General Hospital in Santiago de Cuba, and suffering from biliary cholic, ictero, choluria, nausea, vomit and loss of appetite is presented. The complementary examinations confirmed the choledocolitiasis and cholelitiasis diagnosis, reason why it was necessary to carry out a endoscopic retrograde cholangiopancreatography, endoscopic esphinterotomy and ambulatory laparoscopic cholecystectomy, in a single anesthetic injection. The postoperative clinical course was favorable and she was discharged without complications 24 hours before the intervention

Sudden death after endoscopic retrograde cholangiopancreatography (ERCP)--case report and literature review.

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Hauser, Goran; Milosevic, Marko; Zelić, Marko; Stimac, Davor

2014-12-01

There are only a few cases found in literature regarding air embolism in endoscopic procedures, especially in connection to endoscopic retrograde cholangiopancreatography (ERCP). We are presenting a case of a 56-year-old female patient who suffered from non-Hodgkin lymphoma located in her right groin. She was also diagnosed with choledocholithiasis and underwent ERCP to remove the gallstones. Immediately after the procedure she went into sudden cardiac arrest and subsequently died, despite all of our efforts. We reviewed literature in order to identify possible causes of death because fatal outcome following an uneventful and successful procedure was not expected. It is important to bear in mind all possible complications of ERCP. Our focus during the literature search was on air embolism.

Sutureless choledochoduodenostomy with an intraluminal degradable stent in dog model

Institute of Scientific and Technical Information of China (English)

ZHU Ling-hua; LIANG Xiao; LIN Hui; WANG Yi-fan; ZHU Yi-ping; CAI Xiu-jun

2011-01-01

Background It is difficult and time-consuming for carrying out conventional hand-sewn bilioenteric anastomosis, especially for small bile duct anastomosis and laparoscopic procedure. In order to simplify it, we have developed a novel procedure of sutureless bilioenteric anastomosis with an intraluminal degradable stent. This study aimed to evaluate the feasibility and safety of this technique with cholangioduodenostomy in dog model.Methods A patent intraluminal degradable stent tube for sutureless choledochoduodenostomy in dog model was made with polylactic acid in diameter of 3 mm or 4 mm. Thirty-eight dogs were randomly divided into to a stent group (SG, n=20) and a control group (CG, n=18). Dogs in the SG underwent sutureless choledochoduodenostomy with intraluminal stent, while the CG underwent conventional choledochoduodenostomy (single layer discontinuous anastomosis with absorbable suture). Dogs of each group were divided into 4 subgroups according to time of death (1,3,6, and 12 months postoperatively) to evaluate the healing of anastomosis. Operation time, intraoperative tolerance pressure of anastomosis, rate of postoperative bile leakage, bursting pressure of anastomosis were compared between the two groups. Anastomosis tissue was observed afterwards by pathology evaluation, hydroxyproline content, serum bilirubin, liver enzyme level and magnetic resonance cholangio-pancreatography (MRCP) to assess the stricture.Results All procedures were completed successfully. The surgical time of the SG was significantly less than the CG (SG: (19.2±4.3) minutes, vs. CG: (29.2±7.1) minutes, P=0.000). One bile leakage was occurred in either group. No significant difference of intraoperative tolerance pressure of anastomosis, rate of bile leakage and postoperative bursting pressure of anastomosis, anastomotic stricture, hydroxyproline content, serum bilirubin and liver enzyme level was found between the two groups. MRCP showed no anastomosis stricture and obstruction

Fluorocholangiography: reincarnation in the laparoscopic era-evaluation of intra-operative cholangiography in 3635 laparoscopic cholecystectomies.

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Nassar, Ahmad H M; Mirza, Ahmad; Qandeel, Haitham; Ahmed, Zubir; Zino, Samer

2016-05-01

The introduction of laparoscopic cholecystectomy (LC) resulted in the decline of routine intra-operative cholangiography (IOC). Common bile duct stones are being diagnosed preoperatively using magnetic resonance cholangiopancreatography (MRCP). We aim to evaluate the use and benefits of IOC during laparoscopic biliary surgery at a high-volume biliary surgery unit. Prospective data from 4088 patients undergoing LC over 22 years were analysed. Referral protocols allow one firm to receive the great majority of biliary emergencies and all suspected ductal stones. All patients with gall stones on ultrasound scanning, fit for surgery, will undergo LC during the index admission. MRCP and ERCP are not part of preoperative investigation. A four-port LC is performed with a size 5Fr ureteric catheter within an open cannula to obtain an IOC through right sub-costal port. Of 4088 patients, IOC was attempted in 3691 (90.2 %) and 3635 had a successful IOC (98.4 %). 75 % were females. The mean age was 59 years. Patients presented with one or more of the following: chronic biliary pain in 60 %, acute pain 26.7 %, acute cholecystitis 8.4 %, gallstone pancreatitis 7.8 % and jaundice with or without cholangitis in 19.2 %. A total of 1328 patients (36.5 %) had risk factors for CBD stones. The IOC was abnormal in 975 cases (26.8 %), recording 1599 abnormalities. IOC identified 774 patients with CBD stones (21.3 %), including previously unsuspected CBD stones in 4.7 %. IOC was false negative in 20 cases (0.5 %) found to have stones on basket exploration. A decision not to perform IOC in 453 cases (11 %) was made preoperatively in 74.2 % and intra-operatively in 12.3 %. IOC can be safely and routinely performed in LC. It helps to identify CBD stones, even in patients with no known risk factors, delineate bile duct anatomy and facilitate single-stage management of CBD stones.

An unusual case of prolonged post-endoscopic retrograde cholangiopancreatography jaundice.

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Tziatzios, Georgios; Gkolfakis, Paraskevas; Papanikolaou, Ioannis S; Dimitriadis, George; Triantafyllou, Konstantinos

2016-04-01

Despite the effectiveness of endoscopic retrograde cholangiopancreatography (ERCP) for the treatment of choledocholithiasis, various complications have been described. We herein report the first case of prolonged post-ERCP jaundice due to toxicity of the contrast agent Iobitridol (®XENETIX, Guerbet, Roissy CdG Cedex, France) in a patient who underwent ERCP with sphincterectomy and common bile duct stone removal. While clinical improvement and normalization of aminotransferases and cholestatic enzymes after the procedure, an unexplained increase of direct bilirubin was noticed. A second ERCP was performed one week later, excluding possible remaining choledocholithiasis. Nevertheless, serum direct bilirubin increased further up to 15 mg/dL. Other potential causes of direct hyperbilirubinemia were ruled out and patient's liver biopsy was compatible with drug-induced liver toxicity. Additionally, the cause-result time connection between the use of Iobitridol and bilirubin increase indicated the possibility of a toxic effect related to the repeated use of the particular contrast agent. Iobitridol, a contrast agent, can induce prolonged direct hyperbilirubinemia.

A colangiopancreatografia retrógrada endoscópica pode ser realizada com segurança em caráter ambulatorial Safety of endoscopic retrograde cholangiopancreatography performed in ambulatory centers

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Mara Virginia Lellis Marçal

2005-03-01

á evolução nos pacientes inicialmente liberados, confirmando a segurança na realização da colangiopancreatografia endoscópica retrógrada em ambulatório.BACKGROUND: Endoscopic retrograde cholangiopancreatography is effective technique to approach various biliary and pancreatic disorders. Safety of endoscopic retrograde cholangiopancreatography on an outpatient basis has been questioned. OBJECTIVES: To evaluate the safety of outpatient endoscopic retrograde cholangiopancreatography and describe procedure complications. PATIENTS/METHOD: We prospectively assessed outpatients endoscopic retrograde cholangiopancreatography during 2001 to 2003 period. Complications were defined according to consensus criteria and all adverse effects related to procedure were included. RESULTS: One hundred and ninety five outpatients endoscopic retrograde cholangiopancreatography were performed, 79 (40.5% diagnostic and 116 (59.5% therapeutic. The study group included 112 women, mean age 51 (± 18.9 years. The most common diagnoses were: biliary calculi (30.2%, benign stenosis, (13.8%, malignant obstruction (10.2% and chronic pancreatitis (10.2%. Success was achieved in 88.6% of diagnostic endoscopic retrograde cholangiopancreatography and 78.5% in therapeutic. Complications necessitating observation developed in 10 (5.1% of 195 endoscopic retrograde cholangiopancreatography, among them, 7 (3.6% were hospitalized, (2 acute pancreatitis, 2 perforations, 1 bleeding, 1 cardio-respiratory e 1 fever. Among 188 patients initially discharged 8 (4.2% needed readmission (1 acute pancreatitis, 1 bleeding, 1 perforation, 3 cholangitis, 2 abdominal pain. Comparing the first group where complications were immediately identified to the second, no significant statistical difference concerning to age, sex, diagnoses and procedure difficulty degree was found. CONCLUSION: Sample size and negative statistical results failed to determinate independent risk factors for outpatients endoscopic retrograde

Villous adenoma of the common hepatic duct: the importance of contrast-enhanced ultrasound and endoscopic retrograde cholangiopancreatography for relevant diagnosis. A case report and review of the literature.

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Tefas, Cristian; Tanţău, Marcel; Szenftleben, Alexandru; Chiorean, Liliana; Badea, Radu

2015-12-01

Adenomas are frequently encountered in the lower digestive tract but are rarely diagnosed in the biliary tree. We report a case of villous adenoma of the common hepatic duct. A 58-year old male was admitted with a four week history of intermittent upper right quadrant pain. Gray scale and contrast-enhanced abdominal ultrasound showed a mass inside the common hepatic duct with arterial enhancement and slow wash-out during the late venous phase. Subsequent endoscopic retrograde cholangiopancreatography and intraductal ultrasound confirmed the presence of the lesion. The final histopathological examination showed villous adenoma of the common hepatic duct with high-grade dysplasia. Contrast enhanced ultrasonography used in conjecture with endoscopic retrograde cholangiopancreatography can help in differentiating biliary tumors.

[Obstructive cholangiopathy: are endoscopic retrograde cholangiopancreatography and papillotomy always really necessary?].

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Pierie, J P; van Vroonhoven, T J

1999-07-17

In two women aged 76 and 29 years, who presented with cholangitis and small ductus choledochus calculi and with painless icterus respectively, endoscopic retrograde cholangiopancreatography (ERCP) was carried out with papillotomy. Both developed a duodenal perforation which, however, could not be localized. The first patient eventually died, the second recovered after prolonged hospitalization. A third patient, a 53-year-old man, developed abdominal pain and fever four days after laparoscopic cholecystectomy. ERCP was planned, but in the meantime the patient showed signs of recovery. The ERCP was carried out nevertheless. It failed and the patient suffered a prolonged recovery with necrotizing pancreatitis and multiple operations necessitating a temporary colostoma. In all three patients the endoscopic procedure was performed routinely without strict individualized indication. ERCP and papillotomy may be relatively safe procedures, but it should always be considered whether they will really serve the patient.

The effect of mastication on human motor preparation processing: a study with CNV and MRCP.

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Sakamoto, Kiwako; Nakata, Hiroki; Honda, Yukiko; Kakigi, Ryusuke

2009-07-01

To clarify the effect of mastication on motor preparation processing using electroencephalography (EEG), we investigated the effect of mastication on contingent negative variation (CNV) and reaction time (RT) in Experiment 1, and movement-related cortical potentials (MRCPs) in Experiment 2. The twelve subjects performed four CNV or MRCP sessions, and in the Mastication condition chewed a gum base during the resting period between sessions, Pre (before chewing) and Post 1, 2, and 3 (after chewing). In the Control condition, the subjects performed the same sessions without chewing gum during the intervals between sessions on another day. In Experiment 1, the mean amplitudes of the early- and late-CNV were significantly larger in Mastication than Control at Post 2 and Post 3. RT also differed significantly between Mastication and Control at Post 3. By contrast, in Experiment 2, there were no significant differences between Mastication and Control for the mean amplitudes of MRCPs including Bereitschaftspotential (BP) and negative slope (NS') in any session. These results suggest that mastication influences cognitive processing reflected by CNV with stimulus-triggered movement, rather than motor-related processing reflected by MRCPs relating to self-initiated movement, and provide evidence concerning the mechanisms for the effect of mastication on the human brain.

Magnetic resonance in obstructive jaundice

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Gupta, R.K.; Jena, A.; Khushu, S.; Kakar, A.K.; Mishra, P.K.

1989-01-01

Twelve cases of obstructive jaundice in whom ultrasound failed to demonstrate the site and/or the cause of obstruction of the biliary tract were examined with magnetic resonance imaging (MRI), correctly diagnosing the site and cause of obstruction in 10 of 12 surgically proven cases. In one case of cholangiocarcinoma, the site of obstruction was well shown on MR but a definite cause could not be ascertained. In another patient who developed intermittent jaundice following surgery for choledochal cyst, MR demonstrated a solitary stone in the common hepatic duct. Surgical confirmation could not be achieved as the patient was lost to follow up. There were 6 cases of choledocholithiasis, 3 cases of gall bladder carcinoma and one case each of pancreatic adenocarcinoma and cholangiocarcinoma. It is believed that MRI will provide obstructive jaundice and will be able to minimize the use of percutaneous transhepatic cholangiography (PTC) and endoscopic retrograde cholangiopancreatography (ERCP) in view of its ability to perform multiplanar imaging in multiple sequences. 11 refs., figs., 1 tab

A Spanish multicenter study to estimate the prevalence and incidence of chronic pancreatitis and its complications

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J. Enrique Domínguez-Muñoz

2014-04-01

Full Text Available Background and objective: No nation-wide epidemiological study on the incidence and prevalence of chronic pancreatitis (CP had been thus far carried out in Spain. Our goal is to estimate the prevalence and incidence of CP, as well as to determine the diagnostic and therapeutic criteria used in Spanish pancreas units. Methods: An observarional, descriptive study of hospital pancreas units in Spain. CP-related epidemiology, etiology, manifestations, diagnostic tests, functional complications, and treatments were all assessed using a structured questionnaire. Overall results were estimated by weighting cases in each site. Results: Information was collected from six pancreas units with a sample frame of 1,900,751 inhabitants. Overall prevalence was 49.3 cases per 10(5 population (95 % CI, 46 to 52 and incidence was 5.5 cases per 10(5 inhabitant-years (95 % CI, 5.4 to 5.6. Most common etiologies included tobacco and alcoholism, which were associated with three in every four cases. The most prevalent symptoms were recurring pain (48.8 % and chronic abdominal pain (30.6 %. The most widely used diagnostic method was echoendoscopy (79.8 %, CT (computerized tomography (58.7 %, and MRI (magnetic resonance imaging/MRCP (magnetic resonance cholangiopancreatography (55.9 %. Most prevalent morphologic findings included calcifications (35 % and pseudocysts (27 %. Exocrine (38.8 % and endocrine (35.2 % pancreatic insufficiency had both a similar frequency. Treatments used were rather heterogeneous among sites, with enzyme replacement therapy (40.7 % and insulin (30.9 % being most commonly used. Conclusions: Pancreas units amass a significant number of both prevalent and incident CP cases. Patients seen in these units share a similar typology, and differences between units are greater regarding diagnostic and therapeutic strategies.

Location of disease on imaging may predict radiation exposure during endoscopic retrograde cholangiopancreatography

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Choi, Moon Hyung; Jung, Seung Eun; Yoon, Seung Bae; Lee, In Seokand; Byun, Jae Young

2017-01-01

Endoscopic retrograde cholangiopancreatography (ERCP) is performed for various diseases. The aim of this study is to evaluate the difference of dose-area product (DAP) during the ERCP procedures according to location of the lesion. We performed a retrospective study of consecutive 217 therapeutic ERCP examinations performed between November 2014 and April 2015 at a tertiary care center. ERCP procedures divided into two groups according to location of the lesion identified on imaging: lesions in the common hepatic duct (CHD) or the common bile duct (CBD) and lesions in the hepatic hilum or the intrahepatic duct (IHD). The mean DAP of the hilum-IHD group (48.7 Gy cm 2 ) was significantly higher than that of the CBD-CHD group (34.9 Gy cm 2 ) (P = 0.003). Radiation exposure during ERCP was significantly different according to location of bile duct lesion. (authors)

Occupational exposure to staff during endoscopic retrograde cholangiopancreatography in Sudan

International Nuclear Information System (INIS)

Sulieman, A.; Elzaki, M.; Khalil, M.

2011-01-01

Endoscopic retrograde cholangiopancreatography (ERCP) procedure is an invasive technique that requires fluoroscopic and radiographic exposure. The purpose of this study was to determine the occupational dose of ionising radiation at three gastroenterology departments (Fedial, Soba and Ibn seena hospitals) in Khartoum (Sudan). The radiation dose was measured during 55 therapeutic ERCP procedures. Thermoluminescence dosemeters were used. The mean radiation dose for the first operator was 0.27 mGy for the eye lens, 0.21 for the thyroid, 0.32 for the chest, 0.17 for the hand and 0.22 for the leg. The mean radiation dose for the second operator was 0.21 mGy for the hand and 0.20 mGy for the chest, while the mean radiation dose for the nurse was 0.44 mGy for the hand and 0.19 for the chest. The radiation dose received by the staff in these hospitals was found to be higher than most of the values in the literature. The radiation absorbed dose received by the different organs is relatively low. Additional studies need to be conducted for radiation dose optimisation. (authors)

Endoscopic retrograde cholangiopancreatography after Billroth-Ⅱ gastrectomy and its safety

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LEI Ting

2016-06-01

Full Text Available ObjectiveTo investigate the safety of endoscopic retrograde cholangiopancreatography (ERCP after Billroth-Ⅱ gastrectomy. MethodsA total of 43 patients who were admitted to our hospital and underwent Billroth-Ⅱ gastrectomy from June 2012 to June 2015 were enrolled and underwent ERCP. ResultsOf all 43 patients undergoing ERCP, 39 (90.7% received successful intubation, 2 (4.7% received failed intubation, and 2 (47% experienced the complication of digestive tract perforation. Among the 39 patients who underwent ERCP, 31 (79.5% were diagnosed with common bile duct stones (3 underwent sphincterotomy and 28 underwent endoscopic papillary balloon dilation to remove stones, 6 (15.4% were diagnosed with benign stenosis at the end of bile duct (4 underwent papillary balloon dilation alone and 2 underwent biliary plastic stent implantation, and 1 patient each (2.6% was diagnosed with ampullary tumor and hepatic portal metastasis of gastric cancer and received implantation of metal and plastic stents, respectively. One patient (26% experienced acute pancreatitis after surgery. ConclusionERCP is safe and effective in patients after Billroth-Ⅱ gastrectomy and holds promise for clinical application.

Ductal Mucus Obstruction and Reduced Fluid Secretion Are Early Defects in Chronic Pancreatitis

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Anita Balázs

2018-05-01

Full Text Available Objective: Defective mucus production in the pancreas may be an important factor in the initiation and progression of chronic pancreatitis (CP, therefore we aimed to (i investigate the qualitative and quantitative changes of mucus both in human CP and in an experimental pancreatitis model and (ii to correlate the mucus phenotype with epithelial ion transport function.Design: Utilizing human tissue samples and a murine model of cerulein induced CP we measured pancreatic ductal mucus content by morphometric analysis and the relative expression of different mucins in health and disease. Pancreatic fluid secretion in CP model was measured in vivo by magnetic resonance cholangiopancreatography (MRCP and in vitro on cultured pancreatic ducts. Time-changes of ductal secretory function were correlated to those of the mucin production.Results: We demonstrate increased mucus content in the small pancreatic ducts in CP. Secretory mucins MUC6 and MUC5B were upregulated in human, Muc6 in mouse CP. In vivo and in vitro fluid secretion was decreased in cerulein-induced CP. Analysis of time-course changes showed that impaired ductal ion transport is paralleled by increased Muc6 expression.Conclusion: Mucus accumulation in the small ducts is a combined effect of mucus hypersecretion and epithelial fluid secretion defect, which may lead to ductal obstruction. These results suggest that imbalance of mucus homeostasis may have an important role in the early-phase development of CP, which may have novel diagnostic and therapeutic implications.

Bronchobiliary Fistula Evaluated with Magnetic Resonance Imaging

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Ragozzino, A.; Rosa, R. De; Galdiero, R.; Maio, A.; Manes, G.

2005-01-01

Bronchobiliary fistula (BBF) is a rare disorder consisting of a passageway between the biliary ducts and the bronchial tree. Many conditions may give rise to this development. Management of these fistulas is often difficult and can be associated with high morbidity and mortality rates. We present a case of BBF developing after hemihepatectomy in a 74-year-old man treated with endoscopic biliary drainage and illustrate MRCP findings

Advances in endoscopic retrograde cholangiopancreatography for the treatment of cholangiocarcinoma.

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Uppal, Dushant S; Wang, Andrew Y

2015-06-25

Cholangiocarcinoma (CCA) is a malignancy of the bile ducts that carries high morbidity and mortality. Patients with CCA typically present with obstructive jaundice, and associated complications of CCA include cholangitis and biliary sepsis. Endoscopic retrograde cholangiopancreatography (ERCP) is a valuable treatment modality for patients with CCA, as it enables internal drainage of blocked bile ducts and hepatic segments by using plastic or metal stents. While there remains debate as to if bilateral (or multi-segmental) hepatic drainage is required and/or superior to unilateral drainage, the underlying tenant of draining any persistently opacified bile ducts is paramount to good ERCP practice and good clinical outcomes. Endoscopic therapy for malignant biliary strictures from CCA has advanced to include ablative therapies via ERCP-directed photodynamic therapy (PDT) or radiofrequency ablation (RFA). While ERCP techniques cannot cure CCA, advancements in the field of ERCP have enabled us to improve upon the quality of life of patients with inoperable and incurable disease. ERCP-directed PDT has been used in lieu of brachytherapy to provide neoadjuvant local tumor control in patients with CCA who are awaiting liver transplantation. Lastly, mounting evidence suggests that palliative ERCP-directed PDT, and probably ERCP-directed RFA as well, offer a survival advantage to patients with this difficult-to-treat malignancy.

Changes in the diagnostic and therapeutic methods for Lemmel′s syndrome over the past 20 years in China

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ZHU Fengshang

2018-03-01

Full Text Available ObjectiveTo investigate the changes in the diagnostic and therapeutic methods for Lemmel′s syndrome over the past 20 years in China, and to provide experience for standardized diagnosis and treatment of this disease. MethodsA retrospective analysis was performed for the clinical data of 23 patients with Lemmel′s syndrome who were diagnosed and treated in Tongji Hospital of Tongji University from January 1998 to June 2017 and 384 patients with Lemmel′s syndrome reported in China during the same period of time (407 patients in total. According to the admission time, the patients were divided into groups A (139 patients admitted from 1998 to 2007 and B (268 patients admitted from 2008 to 2017. The patients′ clinical features, diagnostic and therapeutic methods, and prognosis were recorded. The t-test was used for comparison of normally distributed continuous data between groups, and the Wilcoxon rank sum test was used for comparison of non-normally distributed continuous data between groups, the chi-square test was used for comparison of categorical data between groups. ResultsCompared with group A, group B had significantly higher age of onset (67.8±17.8 vs 62.3±12.3, t=-13.238, P= 0.019 and incidence rate of cholangitis (45.9% vs 32.4%, χ2=6.903, P=0.009. As for diagnostic methods, compared with group A, group B had a significantly higher proportion of patients who used multi-slice spiral CT (MSCT (26.9% vs 8.6%, χ2=18.576, P＜0.001, endoscopic ultrasonography (EUS (15.7% vs 5.8%, χ2=8.352, P=0.004, magnetic resonance cholangiopancreatography (MRCP (75.0% vs 33.1%, χ2=67.303, P＜0.001, or endoscopic retrograde cholangiopancreatography (ERCP (63.4% vs 36.7%, χ2=26377, P＜0.001, while the two groups had a similar false positive rate (22.8% vs 28.1%, χ2=1.385, P=0.239. As for therapeutic methods, compared with group A, group B had a significantly higher proportion of patients who underwent ERCP combined with conservative

Fatal air embolism during endoscopic retrograde cholangiopancreatography (ERCP): An 'impossible' diagnosis for the forensic pathologist.

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Marchesi, Matteo; Battistini, Alessio; Pellegrinelli, Moira; Gentile, Guendalina; Zoja, Riccardo

2016-01-01

Fatal air embolism related to endoscopic retrograde cholangiopancreatography is a very rare phenomenon. The authors describe the case of a 51-year-old female patient who developed this mortal complication; a computed tomography (CT) examination was performed in articulo mortis by the physicians. Autopsy was unreliable because of bizarre post-mortem changes (reabsorption of intra-cardiac gas vs. conservation of intra-cranial gas) and a lack of strong diagnostic value of histological findings. The right diagnosis was possible thanks only to the CT examination that permitted the assumption of this possible cause of death before the autopsy and to prepare the necessary procedures to recognise and probe air embolism. This case exemplifies how early post-mortem imaging can be crucial to avoid a wrong diagnosis. © The Author(s) 2015.

Pseudotumor of the distal common bile duct at endoscopic retrograde cholangiopancreatography

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Tan, Justin H.; Coakley, Fergus V; Wang, Zhen J.; Poder, Liina; Webb, Emily; Yeh, Benjamin M.

2010-01-01

Background Prior studies have described a pseudocalculus appearance in the distal common bile duct as a normal variant at cholangiography. The objective of this study is to describe the occurrence of pseudotumor in the distal common bile duct at endoscopic retrograde cholangiopancreatography (ERCP). Methods Nine patients who underwent ERCP between May 2004 and July 2008 were identified as having a transient eccentric mural-based filling defect in the distal common bile duct. A single reader systematically reviewed all studies and recorded the imaging findings. Results The mean diameter of the filling defect was 9 mm (range, 5 to 11). Eight patients had resolution of the filling defect during the same ERCP or on a subsequent ERCP, and in 2 of these patients the inferior border of the filling defect was not well visualized. The other patient underwent surgical resection of a presumed tumor with no evidence of malignancy on surgical pathology. Conclusion An eccentric mural-based filling defect in the distal common bile duct can be artifactual in nature and may reflect transient contraction of the sphincter of Oddi. Recognition of this pseudotumor may help avoid unnecessary surgery. PMID:21724120

Assessment of patient dose and radiogenic risks during endoscopic retrograde cholangiopancreatography

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Sulieman, A.; Elzaki, M. [Sudan University of Science and Technology, College of Medical Radiologic Science, P. O. Box 1908, Khartoum 11111 (Sudan); Alkhorayef, M.; Babikir, E. [King Saud University, College of Applied Sciences, Radiological Sciences Department, P. O. Box 10219, Riyadh 11433 (Saudi Arabia); Abuzaid, M. [University of Sharjah, College of Health Sciences, Medical Diagnostic Imaging Department, Sharjah (United Arab Emirates); Dalton, A.; Bradley, D., E-mail: Abdelmoneim_a@yahoo.com [University of Surrey, Centre for Nuclear and Radiation Physics, Department of Physics, GU2-7XH, Guildford, Surrey (United Kingdom)

2015-10-15

Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive technique that has been used for over 30 years in the diagnosis and management of pancreaticobiliary disorders. The objectives of this study were to evaluate the patient entrance surface air kerma doses (ESAK) and estimate the organ and effective doses during ERCP in three hospitals in Khartoum. A total of 55 patients were examined in three hospitals in Khartoum state, Sudan. Calibrated thermoluminescence dosimeters (TLD)-Gr-200-A)) were used to measure patients ESAK. The overall mean of ESAK for all ERCP procedures was 42.4 mGy. The mean patient ESAK in Fedail, Soba and Ibn sena centers were 26.7 mGy, 26.0 mGy, 72.4 mGy, respectively. The effective doses in three centers were 1.6, 1.56 and 2.67 mSv in that order and the overall mean effective dose was 2.01 mSv. Patient radiation doses vary widely among the different hospitals. Patient ESAK is low compared to previous studies in the light of the current practice. Patient dose was decreased significantly in the last two decades. (Author)

Assessment of patient dose and radiogenic risks during endoscopic retrograde cholangiopancreatography

International Nuclear Information System (INIS)

Sulieman, A.; Elzaki, M.; Alkhorayef, M.; Babikir, E.; Abuzaid, M.; Dalton, A.; Bradley, D.

2015-10-01

Endoscopic retrograde cholangiopancreatography (ERCP) is an invasive technique that has been used for over 30 years in the diagnosis and management of pancreaticobiliary disorders. The objectives of this study were to evaluate the patient entrance surface air kerma doses (ESAK) and estimate the organ and effective doses during ERCP in three hospitals in Khartoum. A total of 55 patients were examined in three hospitals in Khartoum state, Sudan. Calibrated thermoluminescence dosimeters (TLD)-Gr-200-A)) were used to measure patients ESAK. The overall mean of ESAK for all ERCP procedures was 42.4 mGy. The mean patient ESAK in Fedail, Soba and Ibn sena centers were 26.7 mGy, 26.0 mGy, 72.4 mGy, respectively. The effective doses in three centers were 1.6, 1.56 and 2.67 mSv in that order and the overall mean effective dose was 2.01 mSv. Patient radiation doses vary widely among the different hospitals. Patient ESAK is low compared to previous studies in the light of the current practice. Patient dose was decreased significantly in the last two decades. (Author)

Pancreatic cancer screening employing noncontrast magnetic resonance imaging combined with ultrasonography

International Nuclear Information System (INIS)

Kuroki-Suzuki, Seiko; Nagashima, Chieko; Machida, Minoru; Muramatsu, Yukio; Moriyama, Noriyuki; Kuroki, Yoshifumi; Nasu, Katsuhiro

2011-01-01

We have conducted an initial evaluation on the potential of combining noncontrast magnetic resonance imaging (MRI) and ultrasonography (US) to screen for pancreatic cancer. An independent ethics committee approved this study. A total of 2511 patients who underwent US were enrolled. Among them, noncontrast MRI was performed in patients in whom the entire pancreas was difficult to depict or in those with US-suspected pancreatic lesions. In total, using 1.5-T MRI, T1- and T2-weighted imaging, magnetic resonance cholangiopancreatography, and diffusion-weighted imaging, we acquired a variety of images. The efficacy of US and MRI in screening for pancreatic lesions, including pancreatic cancer, was evaluated. Of 2511 patients, 184 underwent MRI, and the pancreas was demonstrated in all of them. Among the 2511, five pancreatic cancers were detected by MRI combined with US (detection rate 0.20%). Of the five pancreatic cancers, three were detected by US (detection rate 0.12%) and two by MRI. Four of the five pancreatic cancers were resectable. By combining noncontrast MRI with US, pancreatic cancer can be detected with high accuracy. Other pancreatic lesions that require follow-up, including intraductal papillary mucinous neoplasms, can also be detected. Thus, pancreatic cancer screening with a combination of US and MRI is suggested. (author)

The Role of Per Oral Cholangiopancreatoscopy (POCPS in Complicated Pancreaticobiliary Disease

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Ari F Syam

2016-05-01

Full Text Available A fifty-five year old female patient presented with jaundice, subfebrile fever and dark yellow urine since one month before admission. She lost weight 10 kilograms during one month. One day before admission to Ciptomangunkusumo General Hospital, she complained of worsened abdominal pain at right upper quadrant urging her to come to the emergency room. An abdominal examination revealed Murphy sign, mild hepatomegaly and deeply icteric sclera. Serum bilirubin was 21.8 mg/dl, alkaline phosphatase and gamma-glutamyltransferase levels were significantly elevated (1090 IU/L and 560 IU/L consecutively while the transaminases were moderately high (ALT 80 U/L. The C-reactive protein was 555 mg/L. An abdominal ultrasound examination revealed dilatation of right and left intrahepatic bile duct and presence of common hepatic duct stone. Subsequent magnetic resonance imaging/ magnetic cholangiopancreatography (MRI/ MRCP revealed intrahepatic bile duct dilatation, multiple CBD stone and benign stricture at common hepatic duct causing right and left intrahepatic bile duct obstruction.We assessed the patient as acute cholangitis and obstructive jaundice suspected to be caused by biliary duct stone then we performed endoscopic retrograde cholangiopancreatography (ERCP, we revealing stenosis at distal CBD, multiple CBD stone, giant stone in CHD and dilatation of bilateral IHBD. We performed CBD stone extraction then inserted biliary stent for drainage. Then we planned to do second ERCP with SpyGlassTM for giant stone extraction. After the first ERCP, the clinical condition of the patient improved and the bilirubin decreased to 10 mg/dL. In the next two weeks we performed a second ERCP to extract the giant stone with SpyGlass TM. However, after we inserted SpyGlassTM into the biliary duct, what we found were not as we expected before. We revealed that there was a mass in biliary duct and there was no CBD stone. We did the biopsy and inserted a new plastic stent

Biliary and pancreatic stenting: Devices and insertion techniques in therapeutic endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography

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Mangiavillano, Benedetto; Pagano, Nico; Baron, Todd H; Arena, Monica; Iabichino, Giuseppe; Consolo, Pierluigi; Opocher, Enrico; Luigiano, Carmelo

2016-01-01

Stents are tubular devices made of plastic or metal. Endoscopic stenting is the most common treatment for obstruction of the common bile duct or of the main pancreatic duct, but also employed for the treatment of bilio-pancreatic leakages, for preventing post- endoscopic retrograde cholangiopancreatography pancreatitis and to drain the gallbladder and pancreatic fluid collections. Recent progresses in techniques of stent insertion and metal stent design are represented by new, fully-covered lumen apposing metal stents. These stents are specifically designed for transmural drainage, with a saddle-shape design and bilateral flanges, to provide lumen-to-lumen anchoring, reducing the risk of migration and leakage. This review is an update of the technique of stent insertion and metal stent deployment, of the most recent data available on stent types and characteristics and the new applications for biliopancreatic stents. PMID:26862364

Endoscopic retrograde cholangiopancreatography with rendezvous cannulation reduces pancreatic injury.

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Swahn, Fredrik; Regnér, Sara; Enochsson, Lars; Lundell, Lars; Permert, Johan; Nilsson, Magnus; Thorlacius, Henrik; Arnelo, Urban

2013-09-28

To examine whether rendezvous endoscopic retrograde cholangiopancreatography (ERCP) is associated with less pancreatic damage, measured as leakage of proenzymes, than conventional ERCP. Patients (n = 122) with symptomatic gallstone disease, intact papilla and no ongoing inflammation, were prospectively enrolled in this case-control designed study. Eighty-one patients were subjected to laparoscopic cholecystectomy and if intraoperative cholangiography suggested common bile duct stones (CBDS), rendezvous ERCP was performed intraoperatively (n = 40). Patients with a negative cholangiogram constituted the control group (n = 41). Another 41 patients with CBDS, not subjected to surgery, underwent conventional ERCP. Pancreatic proenzymes, procarboxypeptidase B and trypsinogen-2 levels in plasma, were analysed at 0, 4, 8 and 24 h. The proenzymes were determined in-house with a double-antibody enzyme linked immunosorbent assay. Pancreatic amylase was measured by an enzymatic colourimetric modular analyser with the manufacturer's reagents. All samples were blinded at analysis. Post ERCP pancreatitis (PEP) occurred in 3/41 (7%) of the patients cannulated with conventional ERCP and none in the rendezvous group. Increased serum levels indicating pancreatic leakage were significantly higher in the conventional ERCP group compared with the rendezvous ERCP group regarding pancreatic amylase levels in the 4- and 8-h samples (P = 0.0015; P = 0.03), procarboxypeptidase B in the 4- and 8-h samples (P rendezvous cannulation technique compared with patients that underwent cholecystectomy alone (control group). Post procedural concentrations of pancreatic amylase and procarboxypeptidase B were significantly correlated with pancreatic duct cannulation and opacification. Rendezvous ERCP reduces pancreatic enzyme leakage compared with conventional ERCP cannulation technique. Thus, laparo-endoscopic technique can be recommended with the ambition to minimise the risk for post ERCP

Differentiation between autoimmune pancreatitis and pancreatic carcinoma based on endoscopic retrograde cholangiopancreatography findings

International Nuclear Information System (INIS)

Nishino, Takayoshi; Oyama, Hiroyasu; Shiratori, Keiko; Toki, Fumitake

2010-01-01

We have reviewed the endoscopic retrograde cholangiopancreatography (ERCP) images of patients with autoimmune pancreatitis (AIP) and pancreatic carcinoma (Pca) in an attempt to identify findings that would facilitate making a differential diagnosis between AIP and Pca. The study cohort consisted of 39 patients diagnosed with AIP and 62 patients diagnosed with Pca. The ERCP findings in the pancreatic duct and biliary tract were compared between the two groups. The ERCP images revealed that AIP patients had a higher prevalence of narrowing of the main pancreatic duct (MPD) for ≥3 cm of its length and a higher prevalence for the presence of side branches in the narrowed portion of the MPD than Pca patients (p 5 cm of its length and the presence of side branches. Among our patient cohort, the ERCP findings in terms of the length of the narrowed portion of the MPD, the presence of side branches, and maximal diameter of the upstream MPD enabled differential diagnosis between AIP and Pca in most of the cases. However, it must be borne in mind that some Pca patients have ERCP findings similar to those of AIP patients. (author)

Sensitivity of ultrasonography in the demonstration of common bile duct and its ranking in comparison with intravenous cholangiography and endoscopic retrograde cholangiopancreatography

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Myllylae, V.; Paeivaensalo, M.; Pyhtinen, J.; Kairaluoma, M.I.; Niemelae, S.; Oulu Univ.; Oulu Univ.

1984-01-01

A series of 75 patients with surgically verified common bile duct (CBD) stones were re-examined in retrospect, in order to ascertain the sensitivity of ultrasonography (US) in the detection of CBD. The sensitivity of US turned out to be 19%. US detected bile duct dilatation in 58% and all the CBD stones detected or suspected were seen in cases with bile duct dilatation. The sensitivity of intravenous cholangiography (IVC) proved to be 24%. Endoscopic retrograde cholangiopancreatography (ERCP), however, was found to be by far the most sensitive method, since it demonstrated 84% of the CBD stones. (orig.) [de

[Value of MR imaging in the diagnosis of intraductal papillary neoplasm of the bile duct].

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Song, Fengxiang; Zhou, Jun; Shi, Yuxin; Zeng, Mengsu; Zhou, Kangrong; Ding, Yuqin; Cao, Yingli; Zhou, Jianjun

2015-01-01

To analyze the value of MR imaging in diagnosis of intraductal papillary neoplasm of the bile duct (IPN-B). Fourteen patients with intraductal papillary neoplasms of the bile duct confirmed by surgical pathology were included in this study. The patients underwent MR routine plain scanning and enhancement scanning (including T1WI, T2WI with fat suppression, FALSH T1WI, and three-phase enhancement scanning), diffusion weighted imaging(DWI) and magnetic resonance cholangiopancreatography (MRCP) before operation. The imaging data were reviewed and analyzed retrospectively in comparison with the surgical and pathological results. In these patients, 7 cases had tumors located in the left lobe, 2 cases had tumors in both the left and right lobes, 2 cases in the hepatic hilum, 2 cases in the common bile duct, and 1 case in both the right lobe and the common bile duct. Solitary or multiple intraductal masses could be found in 12 cases, with 11 cases appeared as papillary masses and one case as flat mass. In the other two cases the tumor was not visible (one case had too many stones, and in another case the tumor was too small). The tumors in the 12 cases showed hypointensity on T1WI and hyperintensity on T2WI. On the dynamic contrast-enhanced MRI, 11 cases showed mild and one showed moderate enhancement in arterial phase, and all the cases showed mildly and gradually delayed enhancement. On DWI, the lesion areas showed high signal intensity in all the cases, and the ADC value of the tumor area (1.697×10(-3)mm(2)/s) was significantly lower than that of the normal bile (3.973×10(-3)mm(2)/s) (t = -10.94, P invisible tumors ). In the 3 cases with aneurysmal bile dilatation, the multiple directions of MRCP images helped to find the communication between the aneurysmal dilatation and the bile duct. All the cases showed significant proximal bile duct dilatation (the extent of dilatation >100%), and 9 cases also showed distal bile duct dilatation. Bile duct stones were noted in 6

Retrieval of Surgical Clip from Common Bile Duct by Endoscopic Retrograde Cholangiopancreatography: A Rare Complication of Laparoscopic Cholecystectomy

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Shahid Rasool

2017-04-01

Full Text Available Laparoscopic cholecystectomy has become the standard procedure for the surgical management of symptomatic cholelithiasis. Laparoscopic cholecystectomy is generally considered a safe procedure although a few complications such as major bleeding, wound infection, bile leakage, biliary and bowel injury are well known. We are reporting a case of a thirty-seven year old male who presented with abdominal pain, three weeks after laparoscopic cholecystectomy. Abdominal ultrasound revealed a filling defect in common bile duct with deranged liver function tests. With an impression of choledocholithiasis, his endoscopic retrograde cholangiopancreatography (ERCP was done which revealed a surgical clip impacted in the ampulla. The surgical clip was retrieved successfully by ERCP. Intraductal clip migration is a rarely encountered complication after laparoscopic cholecystectomy. Appropriate management requires timely identification and retrieval during ERCP.

Resitting a high-stakes postgraduate medical examination on multiple occasions: nonlinear multilevel modelling of performance in the MRCP(UK examinations

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McManus IC

2012-06-01

Full Text Available Abstract Background Failure rates in postgraduate examinations are often high and many candidates therefore retake examinations on several or even many times. Little, however, is known about how candidates perform across those multiple attempts. A key theoretical question to be resolved is whether candidates pass at a resit because they have got better, having acquired more knowledge or skills, or whether they have got lucky, chance helping them to get over the pass mark. In the UK, the issue of resits has become of particular interest since the General Medical Council issued a consultation and is considering limiting the number of attempts candidates may make at examinations. Methods Since 1999 the examination for Membership of the Royal Colleges of Physicians of the United Kingdom (MRCP(UK has imposed no limit on the number of attempts candidates can make at its Part 1, Part2 or PACES (Clinical examination. The present study examined the performance of candidates on the examinations from 2002/2003 to 2010, during which time the examination structure has been stable. Data were available for 70,856 attempts at Part 1 by 39,335 candidates, 37,654 attempts at Part 2 by 23,637 candidates and 40,303 attempts at PACES by 21,270 candidates, with the maximum number of attempts being 26, 21 and 14, respectively. The results were analyzed using multilevel modelling, fitting negative exponential growth curves to individual candidate performance. Results The number of candidates taking the assessment falls exponentially at each attempt. Performance improves across attempts, with evidence in the Part 1 examination that candidates are still improving up to the tenth attempt, with a similar improvement up to the fourth attempt in Part 2 and the sixth attempt at PACES. Random effects modelling shows that candidates begin at a starting level, with performance increasing by a smaller amount at each attempt, with evidence of a maximum, asymptotic level for

Resitting a high-stakes postgraduate medical examination on multiple occasions: nonlinear multilevel modelling of performance in the MRCP(UK) examinations.

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McManus, I C; Ludka, Katarzyna

2012-06-14

Failure rates in postgraduate examinations are often high and many candidates therefore retake examinations on several or even many times. Little, however, is known about how candidates perform across those multiple attempts. A key theoretical question to be resolved is whether candidates pass at a resit because they have got better, having acquired more knowledge or skills, or whether they have got lucky, chance helping them to get over the pass mark. In the UK, the issue of resits has become of particular interest since the General Medical Council issued a consultation and is considering limiting the number of attempts candidates may make at examinations. Since 1999 the examination for Membership of the Royal Colleges of Physicians of the United Kingdom (MRCP(UK)) has imposed no limit on the number of attempts candidates can make at its Part 1, Part 2 or PACES (Clinical) examination. The present study examined the performance of candidates on the examinations from 2002/2003 to 2010, during which time the examination structure has been stable. Data were available for 70,856 attempts at Part 1 by 39,335 candidates, 37,654 attempts at Part 2 by 23,637 candidates and 40,303 attempts at PACES by 21,270 candidates, with the maximum number of attempts being 26, 21 and 14, respectively. The results were analyzed using multilevel modelling, fitting negative exponential growth curves to individual candidate performance. The number of candidates taking the assessment falls exponentially at each attempt. Performance improves across attempts, with evidence in the Part 1 examination that candidates are still improving up to the tenth attempt, with a similar improvement up to the fourth attempt in Part 2 and the sixth attempt at PACES. Random effects modelling shows that candidates begin at a starting level, with performance increasing by a smaller amount at each attempt, with evidence of a maximum, asymptotic level for candidates, and candidates showing variation in starting

Evaluation of radiation doses in patient and medical staff during endoscopic retrograde cholangio-pancreatography procedures

International Nuclear Information System (INIS)

Seo, Deoknam; Kim, Kie Hwan; Park, Kyung; Kim, Jung-Su; Han, Seonggyu; Kim, Jungmin

2016-01-01

The radiation exposure dose must be optimised because the hazard resulting from an interventional radiology procedure is long term depending on the patient. The aim of this study was to measure the radiation doses received by the patients and medical staff during endoscopic retrograde cholangio-pancreatography (ERCP) procedures. Data were collected during 126 ERCP procedures, including the dose-area product (DAP), entrance dose (ED), effective dose (E), fluoroscopy time (T) and number of digital radiographs (F). The medical staff members each wore a personal thermoluminescence dosemeter to monitor exposure during ERCP procedures. The mean DAP, ED, E and T were 47.06 Gy cm 2 , 196.06 mGy, 8.93 mSv, 7.65 min and 9.21 images, respectively. The mean dose to the staff was 0.175 mSv and that to the assistant was 0.069 mSv. The dose to the medical staff was minimal when appropriate protective measures were used. The large variation in the patient doses must be further investigated. (authors)

Implementation of remote video auditing with feedback and compliance for manual-cleaning protocols of endoscopic retrograde cholangiopancreatography endoscopes.

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Armellino, Donna; Cifu, Kelly; Wallace, Maureen; Johnson, Sherly; DiCapua, John; Dowling, Oonagh; Jacobs, Mitchel; Browning, Susan

2018-05-01

A pilot initiative to assess the use of remote video auditing in monitoring compliance with manual-cleaning protocols for endoscopic retrograde cholangiopancreatography (ERCP) endoscopes was performed. Compliance with manual-cleaning steps following the initiation of feedback was measured. A video feed of the ERCP reprocessing room was provided to remote auditors who scored items of an ERCP endoscope manual-cleaning checklist. Compliance feedback was provided in the form of reports and reeducation. Outcomes were reported as checklist compliance. The use of remote video auditing to document manual processing is a feasible approach and feedback and reeducation increased manual-cleaning compliance from 53.1% (95% confidence interval, 34.7-71.6) to 98.9% (95.0% confidence interval, 98.1-99.6). Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Radiological diagnosis and intervention of cholangiocarcinomas (CC); Radiologische Diagnostik und Intervention von Cholangiokarzinomen (CC)

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Vogl, T.J.; Zangos, S.; Eichler, K.; Gruber-Rouh, T.; Hammerstingl, R.M.; Weisser, P. [Frankfurt Univ. (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Trojan, J. [Frankfurt Univ. (Germany). Medizinische Klinik I: Gastroenterologie, Endokrinologie, Pneumologie/Allergologie

2012-10-15

To present current data on diagnosis, indication and different therapy options in patients with cholangiocarcinoma (CC) based on an analysis of the current literature and clinical experience. The diagnostic routine includes laboratory investigations with parameters of cholestasis and also serum tumor markers CA19 - 9 and CEA. After ultrasound for clarifying a tumor and/or dilated bile ducts, contrast-enhanced magnetic resonance imaging (MRI) should be performed with magnetic resonance cholangiography (MRCP). The accuracy (positive predictive value) for diagnosing a CC is 37 - 84 % (depending on the location) for ultrasound, 79 - 94 % for computed tomography (CT), and 95 % for MRI and MRCP. An endoscopic retrograde cholangiography (ERCP) can then be planned, especially if biliary drainage or cytological or histological specimen sampling is intended. A curative approach can be achieved by surgical resection, rarely by liver transplantation. However, many patients are not eligible for surgery. In addition to systemic chemotherapy, locoregional therapies such as transarterial chemoembolization (TACE), hepatic arterial infusion (HAI) - also known as chemoperfusion -, drug eluting beads-therapy (DEB) as well as thermoablative procedures, such as laser-induced thermotherapy (LITT), microwave ablation (MWA) and radiofrequency ablation (RFA) can be provided with a palliative intention.

Patient radiation doses in therapeutic endoscopic retrograde cholangiopancreatography in Patras and the key role of the operator

International Nuclear Information System (INIS)

Hadjiconstanti, Anastasia C.; Messaris, Gerasimos A. T.; Panayiotakis, George S.; Thomopoulos, Konstantinos C.

2017-01-01

The patient radiation doses, in conjunction with the operator experience, in therapeutic endoscopic retrograde cholangiopancreatography (ERCP) procedures, performed in our hospital, were obtained. Ninety-six patients participated in the study and were divided into 3 groups, based on the operator experience. The dosimetric indices, fluoroscopy time (FT), cumulative dose (K a,r ) and air kerma-area product (P KA ), were collected. For the total and weight banding group the third quartile values of the distribution of FT, K a,r and P KA were 2.90 and 2.92 min, 6.89 and 6.93 mGy and 1.84 and 1.85 Gycm 2 , respectively, and were comparative or significantly lower than the corresponding values previously reported. Taking as a criterion the operator, the differences in the patient radiation doses were statistically significant, with the highest dose recorded for the operator of the lowest experience degree. The values obtained could contribute in establishing local and national diagnostic reference levels and in optimising ERCP procedure. (authors)

Identification of risk factors for post-endoscopic retrograde cholangiopancreatography pancreatitis in a high volume center.

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Phillip, Veit; Schwab, Miriam; Haf, David; Algül, Hana

2017-01-01

Pancreatitis is the most common complication of endoscopic retrograde cholangiopancreatography (ERCP). Several patients´ or procedure related risk factors for post-ERCP pancreatitis (PEP) have been suggested. The aim of this study was to validate the risk factors for PEP in a high-volume center. All patients undergoing first time ERCP at a tertiary referral center between December 2010 and October 2013 were retrospectively included. PEP was defined according to the Atlanta Classification. 344 patients were included in the final analysis. The risk to develop PEP was increased in patients with chronic pancreatitis (odds ratio 3.7) and after inadvertent cannulation of the pancreatic duct (odds ratio 2.2), which occurred in 26.5% of the patients. Inadvertent cannulation occurred significantly more frequently in patients with difficult cannulation of the papilla duodeni major (odds ratio 12.7; passociated with an increased risk for difficult cannulation (odds ratio 3.0). Inadvertent cannulation of the pancreatic duct is a procedure related risk factor for PEP. Measurements on preventing inadvertent cannulation of the pancreatic duct should be established and studies on prophylactic measurements should focus particularly on patients with inadvertent cannulation of the pancreatic duct.

Risk of pancreatitis after pancreatic duct guidewire placement during endoscopic retrograde cholangiopancreatography.

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Yuki Ishikawa-Kakiya

Full Text Available Advanced techniques have been developed to overcome difficult cannulation cases in endoscopic retrograde cholangiopancreatography (ERCP. Pancreatic duct guidewire placement method (PGW is performed in difficult cannulation cases; it is possible that it places patients at risk of post-ERCP pancreatitis (PEP. The mechanism of PEP is still unclear, but pancreatic duct pressure and injury of pancreatic duct are known causes of PEP. Therefore, we hypothesized a relationship between pancreatic duct diameter and PEP and predicted that PGW would increase the risk of PEP in patients with non-dilated pancreatic ducts. This study aimed to investigate whether PGW increased the risk of PEP in patients with pancreatic duct diameter ≤ 3 mm.We analyzed 332 patients with pancreatic duct ≤ 3 mm who performed first time ERCP session. The primary endpoint was the rate of adverse event of PEP. We evaluated the risk of PEP in patients who had undergone PGW compared to those who had not, using the inverse probability of treatment weighting (IPTW analysis.PGW was found to be an independent risk factor for PEP by univariate analysis (odds ratio [OR], 2.45; 95% confidence interval [CI], 1.12-5.38; p = 0.03 after IPTW in patients with pancreatic duct diameter ≤ 3 mm. Adjusted for all covariates, PGW remained an independent risk factor for PEP (OR, 3.12; 95% CI, 1.33-7.33; p = 0.01.Our results indicate that PGW in patients with pancreatic duct diameter ≤ 3 mm increases the risk of PEP.

Hilar cholangiocarcinoma: diagnosis, treatment options, and management

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Soares, Kevin C.; Kamel, Ihab; Cosgrove, David P.; Herman, Joseph M.

2014-01-01

Hilar cholangiocarcinoma (HC) is a rare disease with a poor prognosis which typically presents in the 6th decade of life. Of the 3,000 cases seen annually in the United States, less than one half of these tumors are resectable. A variety of risk factors have been associated with HC, most notably primary sclerosing cholangitis (PSC), biliary stone disease and parasitic liver disease. Patients typically present with abdominal pain, pruritis, weight loss, and jaundice. Computed topography (CT), magnetic resonance imaging (MRI), and ultrasound (US) are used to characterize biliary lesions. Endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC) assess local ductal extent of the tumor while allowing for therapeutic biliary drainage. MRCP has demonstrated similar efficacies to PTC and ERCP in identifying anatomic extension of tumors with less complications. Treatment consists of surgery, radiation, chemotherapy and photodynamic therapy. Biliary drainage of the future liver remnant should be performed to decrease bilirubin levels thereby facilitating future liver hypertrophy. Standard therapy consists of surgical margin-negative (R0) resection with extrahepatic bile duct resection, hepatectomy and en bloc lymphadenectomy. Local resection should not be undertaken. Lymph node invasion, tumor grade and negative margins are important prognostic indicators. In instances where curative resection is not possible, liver transplantation has demonstrated acceptable outcomes in highly selected patients. Despite the limited data, chemotherapy is indicated for patients with unresectable tumors and adequate functional status. Five-year survival after surgical resection of HC ranges from 10% to 40% however, recurrence can be as high as 50-70% even after R0 resection. Due to the complexity of this disease, a multi-disciplinary approach with multimodal treatment is recommended for this complex disease. PMID:24696835

Reference values of MRI measurements of the common bile duct and pancreatic duct in children

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Gwal, Kriti; Bedoya, Maria A.; Patel, Neal; Darge, Kassa; Anupindi, Sudha A. [University of Pennsylvania Perelman School of Medicine, Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Rambhatla, Siri J. [Beth Israel Medical Center, Department of Pediatrics, Newark, NJ (United States); Sreedharan, Ram R. [University of Pennsylvania, Departments of Gastroenterology, Hepatology and Nutrition, The Children' s Hospital of Philadelphia, Perelman School of Medicine, Philadelphia, PA (United States)

2015-08-15

Magnetic resonance imaging/cholangiopancreatography (MRI/MRCP) is now an essential imaging modality for the evaluation of biliary and pancreatic pathology in children, but there are no data depicting the normal diameters of the common bile duct (CBD) and pancreatic duct. Recognition of abnormal duct size is important and the increasing use of MRCP necessitates normal MRI measurements. To present normal MRI measurements for the common bile duct and pancreatic duct in children. In this retrospective study we searched all children ages birth to 10 years in our MR urography (MRU) database from 2006 until 2013. We excluded children with a history of hepatobiliary or pancreatic surgery. We stratified 204 children into five age groups and retrospectively measured the CBD and the pancreatic duct on 2-D axial and 3-D coronal T2-weighted sequences. We performed statistical analysis, using logistic and linear regressions to detect the age association of the visibility and size of the duct measurements. We used non-parametric tests to detect gender and imaging plane differences. Our study included 204 children, 106 (52%) boys and 98 (48%) girls, with a median age of 33 months (range 0-119 months). The children were distributed into five age groups. The common bile duct was visible in all children in all age groups. The pancreatic duct was significantly less visible in the youngest children, group 1 (54/67, 80.5%; P = 0.003) than in the oldest children, group 5 (22/22, 100%). In group 2 the pancreatic duct was seen in 19/21 (90.4%), in group 3 52/55 (94.5%), and in group 4 39/39 (100%). All duct measurements increased with age (P < 0.001; r-value > 0.423), and the incremental differences between ages were significant. The measurement variations between the axial and coronal planes were statistically significant (P < 0.001); however these differences were fractions of millimeters. For example, in group 1 the mean coronal measurement of the CBD was 2.1 mm and the axial

Reference values of MRI measurements of the common bile duct and pancreatic duct in children

International Nuclear Information System (INIS)

Gwal, Kriti; Bedoya, Maria A.; Patel, Neal; Darge, Kassa; Anupindi, Sudha A.; Rambhatla, Siri J.; Sreedharan, Ram R.

2015-01-01

Magnetic resonance imaging/cholangiopancreatography (MRI/MRCP) is now an essential imaging modality for the evaluation of biliary and pancreatic pathology in children, but there are no data depicting the normal diameters of the common bile duct (CBD) and pancreatic duct. Recognition of abnormal duct size is important and the increasing use of MRCP necessitates normal MRI measurements. To present normal MRI measurements for the common bile duct and pancreatic duct in children. In this retrospective study we searched all children ages birth to 10 years in our MR urography (MRU) database from 2006 until 2013. We excluded children with a history of hepatobiliary or pancreatic surgery. We stratified 204 children into five age groups and retrospectively measured the CBD and the pancreatic duct on 2-D axial and 3-D coronal T2-weighted sequences. We performed statistical analysis, using logistic and linear regressions to detect the age association of the visibility and size of the duct measurements. We used non-parametric tests to detect gender and imaging plane differences. Our study included 204 children, 106 (52%) boys and 98 (48%) girls, with a median age of 33 months (range 0-119 months). The children were distributed into five age groups. The common bile duct was visible in all children in all age groups. The pancreatic duct was significantly less visible in the youngest children, group 1 (54/67, 80.5%; P = 0.003) than in the oldest children, group 5 (22/22, 100%). In group 2 the pancreatic duct was seen in 19/21 (90.4%), in group 3 52/55 (94.5%), and in group 4 39/39 (100%). All duct measurements increased with age (P < 0.001; r-value > 0.423), and the incremental differences between ages were significant. The measurement variations between the axial and coronal planes were statistically significant (P < 0.001); however these differences were fractions of millimeters. For example, in group 1 the mean coronal measurement of the CBD was 2.1 mm and the axial

Single-operator EUS-guided cholangiopancreatography for difficult pancreaticobiliary access (with video).

Science.gov (United States)

Brauer, Brian C; Chen, Yang K; Fukami, Norio; Shah, Raj J

2009-09-01

When conventional ERCP methods fail because of periampullary or ductal obstruction, EUS-guided cholangiopancreatography (EUS-CP) may aid in pancreaticobiliary access. To report our experience when using single-operator EUS-CP. An academic tertiary-referral center. Consecutive patients undergoing EUS-CP were prospectively identified. These patients had undergone failed attempt(s) at therapeutic ERCP. A data sheet was used to record indications, reasons for failed ERCP, EUS-CP visualization of the duct of interest, transpapillary or transenteric intervention, clinical follow-up, and complications. Technical success was decompression of the duct of interest. Clinical success was resolution of jaundice or a > or = 50% reduction in pain or narcotics, as applicable. Between February 2003 and June 2007, EUS-CP was attempted in 20 patients (11 men, 9 women; mean [SD] age 58 +/- 14.9 years). Indications included jaundice (n = 8), biliary stones (n = 3), chronic pancreatitis (n = 6), acute pancreatitis (n = 2), and papillary stenosis (n = 1). Reasons for failed ERCP included periampullary mass (n = 8), intradiverticular papillae (n = 4), and pancreatic duct (PD) stricture (n = 7) or stone (n = 1). Technical success was achieved in 18 of 20 patients (90%). Biliary decompression was obtained in 11 of 12 patients (92%) (7 transpapillary and 4 transenteric-transcholedochal). Pancreatic decompression was obtained in 7 of 8 patients (88%) (3 transpapillary, 4 transgastric). On follow-up, clinical improvement was noted in 15 of 20 patients (70%). For treatment of pain associated with chronic pancreatitis, pain scores decreased by a mean of 1.75 (P = .18). Complications (in 2 of 20 [10%]) included perforation (n = 1) and respiratory failure (n = 1). A single-center nonrandomized observational study with a small patient population. At our academic referral center, single-operator EUS-CP provided decompression of obstructed ducts and may be performed after a failed attempt at

The Role of Perioperative Endoscopic Retrograde Cholangiopancreatography and Biliary Drainage in Large Liver Hydatid Cysts

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A. Krasniqi

2014-01-01

Full Text Available Background. The best surgical technique for large liver hydatid cysts (LHCs has not yet been agreed on. Objectives. The objective of this study was to examine the role of perioperative endoscopic retrograde cholangiopancreatography (ERCP and biliary drainage in patients with large LHCs. Methods. A 20-year retrospective study of patients with LHCs treated surgically at the University Clinical Center of Kosovo (UCCK. We divided patients into 2 groups based on treatment period: 1981–1990 (Group I and 2001–2010 (Group II. Demographic characteristics (sex, age, the surgical procedure performed, complications rate, and outcomes were compared. Results. Of the 340 patients in our study, 218 (64.1% were female with median age of 37 years (range, 17 to 81 years. 71% of patients underwent endocystectomy with partial pericystectomy and omentoplication, 8% total pericystectomy, 18% endocystectomy with capitonnage, and 3% external drainage. In Group I, 10 patients underwent bile duct exploration and T-tube placement; in Group II, 39 patients underwent bile duct exploration and T-tube placement. In addition, 9 patients in Group II underwent perioperative ERCP with papillotomy. The complication rate was 14.32% versus 6.37%, respectively (P=0.001. Conclusion. Perioperative ERCP and biliary drainage significantly decreased the complication rate and improved outcomes in patients with large LHCs.

Identification of risk factors for post-endoscopic retrograde cholangiopancreatography pancreatitis in a high volume center.

Directory of Open Access Journals (Sweden)

Veit Phillip

Full Text Available Pancreatitis is the most common complication of endoscopic retrograde cholangiopancreatography (ERCP. Several patients´ or procedure related risk factors for post-ERCP pancreatitis (PEP have been suggested. The aim of this study was to validate the risk factors for PEP in a high-volume center.All patients undergoing first time ERCP at a tertiary referral center between December 2010 and October 2013 were retrospectively included. PEP was defined according to the Atlanta Classification.344 patients were included in the final analysis. The risk to develop PEP was increased in patients with chronic pancreatitis (odds ratio 3.7 and after inadvertent cannulation of the pancreatic duct (odds ratio 2.2, which occurred in 26.5% of the patients. Inadvertent cannulation occurred significantly more frequently in patients with difficult cannulation of the papilla duodeni major (odds ratio 12.7; p<0.001. ERCP on call was associated with an increased risk for difficult cannulation (odds ratio 3.0.Inadvertent cannulation of the pancreatic duct is a procedure related risk factor for PEP. Measurements on preventing inadvertent cannulation of the pancreatic duct should be established and studies on prophylactic measurements should focus particularly on patients with inadvertent cannulation of the pancreatic duct.

Endoscopic retrograde cholangiopancreatography, endoscopic esphinterotomy and laparoscopic cholecystectomy in a patient with choledocolitiasis and cholelitiasis; Colangiopancreatografia retrograda endoscopica, esfinterotomia endoscopica y colecistectomia laparoscopica en un paciente con coledocolitiasis y colelitiasis

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Riveron Quevedo, Kelly; Irsula Ballaga, Vladimir [Hospital General Docente ' Dr. Juan Bruno Zayas Alfonso' , Santiago de Cuba (Cuba); Gonzalez Ulloa, Lianne [Policlinico Docente ' Josue Pais Garcia' , Santiago de Cuba (Cuba); Deborah LLorca, Armando, E-mail: kellyr@hospclin.scu.sld.cu [Hospital General Docente ' Emilio Barcenas Pier' , II Frente, Santiago de Cuba (Cuba)

2012-07-01

The case report of a 30 year-old presumably healthy patient, who attended the Gastroenterology Department from 'Dr Juan Bruno Zayas Alfonso' Teaching General Hospital in Santiago de Cuba, and suffering from biliary cholic, ictero, choluria, nausea, vomit and loss of appetite is presented. The complementary examinations confirmed the choledocolitiasis and cholelitiasis diagnosis, reason why it was necessary to carry out a endoscopic retrograde cholangiopancreatography, endoscopic esphinterotomy and ambulatory laparoscopic cholecystectomy, in a single anesthetic injection. The postoperative clinical course was favorable and she was discharged without complications 24 hours before the intervention.

Repair of an Endoscopic Retrograde Cholangiopancreatography-Related Large Duodenal Perforation Using Double Endoscopic Band Ligation and Endoclipping

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Keunmo Kim

2017-03-01

Full Text Available Endoscopic closure techniques have been introduced for the repair of duodenal wall perforations that occur during endoscopic retrograde cholangiopancreatography (ERCP. We report a case of successful repair of a large duodenal wall perforation by using double endoscopic band ligation (EBL and an endoclip. Lateral duodenal wall perforation occurred during ERCP in a 93-year-old woman with acute calculous cholangitis. We switched to a forward endoscope that had a transparent band apparatus. A 2.0-cm oval-shaped perforation was found at the lateral duodenal wall. We repaired the perforation by sequentially performing double EBL and endoclipping. The first EBL was performed at the proximal edge of the perforation orifice, and two-thirds of the perforation were repaired. The second EBL, which also included the contents covered under the first EBL, repaired the defect almost completely. Finally, to account for the possible presence of a residual perforation, an endoclip was applied at the distal end of the perforation. The detection and closure of the perforation were completed within 10 minutes. We suggest that double EBL is an effective method for closure.

Endoscopic Ultrasound-guided Rendezvous Technique after Failed Endoscopic Retrograde Cholangiopancreatography: Which Approach Route Is the Best?

Science.gov (United States)

Okuno, Nozomi; Hara, Kazuo; Mizuno, Nobumasa; Hijioka, Susumu; Tajika, Masahiro; Tanaka, Tsutomu; Ishihara, Makoto; Hirayama, Yutaka; Onishi, Sachiyo; Niwa, Yasumasa; Yamao, Kenji

2017-12-01

Objective The endoscopic ultrasound-guided rendezvous technique (EUS-RV) is a salvage method for failed selective biliary cannulation. Three puncture routes have been reported, with many comparisons between the intra-hepatic and extra-hepatic biliary ducts. We used the trans-esophagus (TE) and trans-jejunum (TJ) routes. In the present study, the utility of EUS-RV for biliary access was evaluated, focusing on the approach routes. Methods and Patients In 39 patients, 42 puncture routes were evaluated in detail. EUS-RV was performed between January 2010 and December 2014. The patients were prospectively enrolled, and their clinical data were retrospectively collected. Results The patients' median age was 71 (range 29-84) years. The indications for endoscopic retrograde cholangiopancreatography (ERCP) were malignant biliary obstruction in 24 patients and benign biliary disease in 15. The technical success rate was 78.6% (33/42) and was similar among approach routes (p=0.377). The overall complication rate was 16.7% (7/42) and was similar among approach routes (p=0.489). However, mediastinal emphysema occurred in 2 TE route EUS-RV patients. No EUS-RV-related deaths occurred. Conclusion EUS-RV proved reliable after failed ERCP. The selection of the appropriate route based on the patient's condition is crucial.

Risk Evaluation of Endoscopic Retrograde Cholangiopancreatography-Related Contrast Media Allergic-Like Reaction: A Single Centre Experience

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Félix Trottier-Tellier

2018-01-01

Full Text Available Background and Aims. Few cases of endoscopic retrograde cholangiopancreatography- (ERCP- related contrast media (CM adverse reactions have been reported in the current literature. There is a lack of standardisation in practice regarding premedication prophylaxis for at-risk patients undergoing ERCP and there are few data to guide the practitioners. Our goal is to evaluate the risk of CM adverse reaction in a group of patients with a past history of allergic-like reaction to iodine product undergoing ERCP. Methods. A retrospective chart review study was performed of patients who underwent ERCP at our single centre from January 2010 to December 2015. Results. 2295 ERCPs were performed among 1766 patients. No anaphylactoid or severe adverse reaction occurred. One (0.04% ERCP-related CM benign reaction was reported in a patient known for penicillin allergy. Among 127 ERCPs performed on patients with a prior adverse reaction to iodine, 121 procedures were done without and 6 with a premedication prophylaxis. In both groups, no ERCP-related CM reaction occurred. Conclusions. To our knowledge, we report the largest cohort of iodine allergic patients undergoing ERCP ever published. These results suggest that ERCP-related CM adverse reactions are very rare even among patients at risk for CM reaction.

The clinical and radiological observation of endoscopic retrograde cholangiopancreatography

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Park, Choong Shik; Park, Byoung Lan; Chun, Hyun Woo; Kim, Byung Geun; Park, Hong Bae [Kwangju Christian Hospital, Kwangju (Korea, Republic of)

1981-12-15

Endoscopic retrograde cholangiopancreatography (ERCP) is a new diagnostic method for pancreatic and biliary disease which has been made possible by the development of fiberoptic duodenoscopy. It has been thought that ERCP will serve an important role in the early detection of pancreatic cancer, but in order to detect minor lesions of the pancreas and improve the diagnostic accuracy of resectable pancreatic cancer, Endoscopic Retrograde Parenchymography of the pancreas (ERPP) was developed recently. The authors analyzed 117 cases of ERCP performed at the Kwangju Christian Hospital between January and December 1980, and compared them with the final diagnosis. The results were as follows: 1. One of 117 cases, successful visualization of the duct of concern was achieved in 105 cases. Of these, 25 cases were ERPP. 2. The ratio of males to females was 1.44 : 1. Most patients were in the 4th to 6th decade. 3. The commonest clinical manifestations were upper abdominal pain (77 cases), jaundice (23 cases), indigestion, vomiting and abdominal mass, in order of frequency. 4. Out of 46 cases of suspected pancreatic diseases, the pancreatic duct was visualized in 36 cases, and 24 cases revealed pathognomonic findings. These were diagnosed as 16 cases of pancreatic cancer, 4 cases of chronic pancreatitis, 2 cases of pancreatic pseudocyst and 2 cases of periampullary cancer with pancreas invasion. In pancreatic cancer findings were; encasement, local dilatation, delayed excretion, poor filling, obstruction of pancreatic duct, accompanying C.B.D. obstruction or stenosis and so called double duct sign. The chronic pancreatitis findings included; ductal dilatation (with or without) obstruction, tortuosity with dilated saccular lateral branching, stone formation and the parenchymal filling defect. 5. Out of 71 cases of suspected biliary tract disease, the biliary tract was visualized in 57 cases, and in 31 cases abnormalities were suggested; such as 20 cases of biliary stone, 1 case

The effect of prophylactic peripapillary administration of methylprednisolone in reducing the risk and severity of postendoscopic retrograde cholangiopancreatography pancreatitis: A double blind clinical trial

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Ahmad Shavakhi

2015-01-01

Full Text Available Background : The most common complication of diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP is acute pancreatitis. A number of therapeutic trials have been studied due to reduce the occurrence of postendoscopic retrograde cholangiopancreatography pancreatitis (PEP but many of them were unsuccessful. Periampullary corticosteroid injection was proposed to use as prophylactic agents for PEP because of its anti-inflammatory property with relative low systemic side effects. Materials and Methods : By conducting a double blinded clinical trial study in a single center university hospital, all patients undergoing therapeutic or diagnostic ERCP in our gastrointestinal endoscopy ward, enrolled the study. During ERCP, we randomly assigned the patients in blocks of 40 to undergo a locally injection of methylprednisolone acetate (corticosteroid group or saline (control group on the major papilla and prospectively evaluated the occurrence of PEP pancreatitis in each groups. Clinical and laboratory findings of acute pancreatitis were collected by means of a validated questionnaire during the procedure and before discharge. At baseline and end of the study, were compared pancreatitis prevalence and also its severity by using Chi-square and t-test statistics. Results : The frequency of moderate to severe PEP pain was not significantly between the placebo and corticosteroid receiving group (13.7% ± 3.2% vs. 9.3% ± 2.1%, respectively; P = 0.8. There is no significant difference in the mean concentration of lipase and amylase between corticosteroid receiving group and placebo receiving group at the first, second, and third time. In the corticosteroid receiving group, 3 patients (10.3% while in the control group, 11 patients (11.3% developed pancreatitis. Conclusion: We found no significant difference in PEP rates and also severity between the corticosteroid and placebo groups. The mean increase in serum amylase and amylase level

Diagnosis of choledocholithiasis and therapeutic results with endoscopic retrograde cholangiopancreatography; Diagnostico de la coledocolitiasis y resultados de su terapeutica mediante colangiponcreatografia retrograda endoscopica

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Ramos Pachon, Carlos; Gonzalez Cansino, Juan; Fernandez Maderos, Irma [Centro Investigaciones Medicoquirurgicas (CIMEQ), La Habana (Cuba)

2009-07-01

A descriptive, prospective study was carried out on 451 patients that were attended for endoscopic retrograde cholangiopancreatography at CIMEQ's Hospital from January 2004-March 2006. The sample was constituted by 353 patients with choledocholithiasis suspicion. The information was search in the reports of ERCP and the variables were analyzed with the objective of evaluating the diagnostic possibilities and the therapy for choledocholithiasis by ERCP. Choledocholithiasis was detected in 1/4 of the patients with indication of ERCP, and was more frequent in patients of the female sex and in patients older than 40 years. The jaundice was the main clinical condition that motivated the ERCP in the patients with choledocholithiasis. The diagnostic effectiveness of the alkaline phosphatase and the ultrasound was not high. The treatment of the choledocholithiasis by means of ERCP showed good results and low morbidity

[Retrospective evaluation of 500 endoscopic cholangiopancreatographies performed at the Instituto Nacional de la Nutrición "Salvador Zubiran"].

Science.gov (United States)

Elizondo, J; Gallo, S; Valdovinos, M A; Paez, R

1989-01-01

We evaluated 500 endoscopic retrograde cholangiopancreatographies (ERCP) performed on 422 patients during a 5-year period in the Gastrointestinal Endoscopy Department, Instituto Nacional de la Nutrición Salvador Zubirán, México, D.F. ERCP combines endoscopic and radiologic techniques in order to obtain high quality opacification of pancreatic and biliary ducts. The rate of success for cannulation was 90%; desired duct opacification was possible in 89%. The most frequent indication for ERCP was to establish the differential diagnosis for jaundice; biliary stones in the common bile duct was the most frequent diagnosis, followed by normal biliary ducts. Pancreatography was normal in 74% of patients. ERCP complications were detected in 5.6%; fever and transient pain was the most common complaint in 1.6%. Mortality attributable to the procedure was 0.8%. From histological corroboration of cases by surgery or postmortem studies, diagnostic sensitivity was 92%, specificity 76%, positive predictive value 96% and a prevalence of 89%. We conclude that ERCP is highly sensitive and specific in diagnosing bilio-pancreatic-duodenal disease. Our results are comparable to other's experiences published throughout the world.

Percutaneous management of bile duct injury after laparoscopic cholecystectomy

International Nuclear Information System (INIS)

Islim, F.; Ors, S.; Salik, A.; Guven, K.; Yanar, F.; Alis, H.

2012-01-01

Full text: Introduction: The risk of bile duct injury after laparoscopic cholecystectomy is higher than open cholecystectomy. Objective: To discuss the importance of minimally invasive treatment options in the management of bile duct injuries after laparoscopic cholecystectomy and to present our approach in the management. Materials and methods: Management of 25 patients with symptomatic bile duct injury after laparoscopic cholecystectomy was retrospectively evaluated. Percutaneous collection drainage, endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTC) and percutaneous biliary drainage were performed for the management of the patients. Results: Mean age of the patients (15 women, 10 men) was 55. Either ultrasonography or computed tomography guided percutaneous drainage was performed in 13 patients. 9 of them completely recovered only with percutaneous drainage. In 4 of them ERCP was performed because of high drainage volume. In 9 of the patients with jaundice and high bilirubin levels ERCP was performed as the first option. And 3 patients were reoperated because of acute abdomen signs. ERCP, MRCP and PTC revealed type A in 7, type E2 in 3, type E3 in 3 and type E4 in 1 of the patients according to Strasberg classification. Conclusion: Presenting symptoms of the patients with symptomatic bile duct injury are useful in the determination of the treatment option.

Carbon dioxide insufflation is superior to air insufflation during endoscopic retrograde cholangiopancreatography: A randomized trial

Directory of Open Access Journals (Sweden)

Santosh Darisetty

2016-01-01

Full Text Available Background: Carbon dioxide (CO 2 insufflation has been shown to be superior to air insufflation in colonoscopy, and double balloon enteroscopy. However, the value of CO 2 insufflation in endoscopic retrograde cholangiopancreatography (ERCP is not established. This study aims to assess the efficacy and safety of CO 2 insufflation during ERCP. Materials and Methods: Consecutive patients referred for ERCP at a single center were randomized to either air or CO 2 insufflation during ERCP. The primary objectives were a post-ERCP abdominal pain (measured by 10 cm visual analog scale [VAS] 30 and 90 min, and 3 h and 24 h after ERCP. Secondary objectives included end-tidal CO 2 (ETCO 2 values and procedural complications. Results: We randomized 298 patients; 149 into air group and 149 into CO 2 group. The VAS score for pain was higher in the air group compared to the CO 2 group at 30 min, with a median of 1 (interquartile range 1-0 versus median of 1 (interquartile range 1-0; P = 0.031 and 90 min after the procedure with a median of 0 (interquartile range 1-0 versus median of 0 (interquartile range 0-0; P = 0.006. There were no serious adverse events, and the ETCO 2 was within normal limits in both groups. Conclusions: CO 2 insufflation is superior to air insufflation during ERCP with regard to patient pain and discomfort and warrants wide adoption. Clinical Trials.gov registration number NCT 01321203.

Comparison of Clinical Effects of Dexketoprofen and Paracetamol Used for Analgesia in Endoscopic Retrograde Cholangiopancreatography.

Science.gov (United States)

Akıncı, Nuran; Bakan, Nurten; Karaören, Gülşah; Tomruk, Senay Göksu; Sökmen, Hacı Mehmet; Yanlı, Yonca; Akçay, Mehmet Erdem

2016-02-01

This study aimed to compare 50 mg dexketoprofen vs. 1 g paracetamol that were parenterally administered before endoscopic retrograde cholangiopancreatography (ERCP) under sedoanalgesia with comparable anaesthesia depth regarding haemodynamic, pain, narcotic analgesic requirement, recovery and post-procedural cognitive functions. Overall, 80 ASA I-III patients aged 18-75 years who were undergoing scheduled ERCP were randomly assigned into three groups. In all patients, the mini-mental test (MMT) was conducted before the procedure. No drug was administered to controls (Group C; n=26); patients were transferred to ERCP unite 30 min after parenteral dexketoprofen (50 mg) in group D (n=27) and paracetamol (1 g) in group P (n=27). The standard monitoring was applied. After intravenously administering loading doses of midazolam (0.02 mgkg) and propofol (1 mg kg(-1)), propofol infusion was administered at a dose of 2-4 mg kg(-1) h(-1) to maintain a bispectral index value of 50-70. Fentanyl (0.05 μg kg(-1)) was intravenously administered when patients experienced pain. Haemodynamic effects, additional analgesic requirement, adverse effects during procedure, time to reach Aldrete score of 9 and satisfaction of an endoscopist and patient were recorded. MMT was repeated 3 h after completing the procedure. Fentanyl requirement during the procedure was significantly low in group D (pdexketoprofen provided better haemodynamic effect and pain control, thereby decreasing incidence of adverse events by reducing the requirement for narcotic analgesics.

MRI of the abdomen – how we do it?

International Nuclear Information System (INIS)

Zlatanov, Y.; Penkov, M.

2013-01-01

slices allowing good spatial resolution. Better suppression of adipose tissue and reduction of the motor artifacts allows better contrast resolution and better quality images. The diagnostic potential of magnetic resonance cholangiopancreatography is almost as close to that of endoscopic retrograde cholangiopancreatography, thereby the need for most diagnostic endoscopic retrograde cholangiopancreatography is eliminating. Looking to the future, it may be carried out more detailed functional assessment of the organs in the abdomen. Secretin - enhanced cholangiopancreatography provides information for exocrine pancreatic function. Diffusion, MRI perfusion and magnetic resonance elastography is currently used for experimental purposes. In the near future it is expected to become a part of the protocol in special indications

Diagnosis of choledocholithiasis and its therapeutic results with endoscopic retrograde cholangiopancreatography; Diagnostico de la coledocolitiasis y resultados de su terapeutica mediante colangiponcreatografia retrograda endoscopica

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Ramos Pachon, Carlos; Gonzalez Cansino, Juan; Fernandez Maderos, Irma; Samada Suarez, Marcia [Centro Investigaciones Medicoquirurgicas (CIMEQ), La Habana (Cuba)

2009-07-01

A descriptive, prospective study was carried out on 451 patients that were attended for endoscopic retrograde cholangiopancreatography at CIMEQ's Hospital from January 2004-March 2006. The sample was constituted by 353 patients with choledocholithiasis suspicion. The information was search in the reports of ERCP and the variables were analyzed with the objective of evaluating the diagnostic possibilities and the therapy for choledocholithiasis by ERCP. Choledocholithiasis was detected in 1/4 of the patients with indication of ERCP, and was more frequent in patients of the female sex and in patients older than 40 years. The jaundice was the main clinical condition that motivated the ERCP in the patients with choledocholithiasis. The diagnostic effectiveness of the alkaline phosphatase and the ultrasound was not high. The treatment of the choledocholithiasis by means of ERCP showed good results and low morbidity

The establishment of local diagnostic reference levels in endoscopic retrograde cholangiopancreatography: a practical tool for the optimisation and for quality assurance management

International Nuclear Information System (INIS)

Saukko, E.; Henner, A.; Nieminen, M.T.; Ahonen, S.-M.

2017-01-01

Fluoroscopic procedures are an area of special concern in relation to radiation protection. The aim of this study was to describe the current level of patient radiation doses in endoscopic retrograde cholangiopancreatography (ERCP) collected from a single centre, as well as to establish and review local diagnostic reference levels (DRLs) in ERCP. A total of 100 patients' radiation doses in ERCP were recorded, and the third-quartile method was adopted to establish local DRLs for ERCP. The mean dose area product (DAP) was 2.05 Gy cm 2 , fluoroscopy time (FT) 1.7 min and the number of images was 3. The proposed local DRLs for ERCP were 3.00 Gy cm 2 and 3.0 min. Local DRLs were reviewed in a sample of 25 patients 5 y after they had been established. In reviewing data, the averages of DAP and FT were below the local DRLs. Local DRLs help in the optimisation process of fluoroscopic procedures and guides to a good clinical practice. (authors)

Cholangiocarcinoma in Magnetic Resonance Cholangiopancreatography and Fascioliasis in Endoscopic Ultrasonography

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Amir Houshang Mohammad Alizadeh

2011-10-01

Full Text Available Fascioliasis is a worldwide zoonotic infection with Fasciola hepatica and Fasciola gigantica. The zoonoses are particularly endemic in sheep-raising countries and are also endemic in Iran. Typical symptoms that may be associated with fascioliasis can be divided by phases of the disease, including the acute or liver phase, the chronic or biliary phase, and ectopic or pharyngeal fascioliasis. Cholestatic symptoms may be absent, and in some cases diagnosis and treatment may be preceded by a long period of abdominal pain, eosinophilia and vague gastrointestinal symptoms. We report a case with epigastric and upper quadrant abdominal pain for the last 4 years, with imaging suggesting cholangiocarcinoma. Considering a new concept of endoscopic ultrasonography, at last F. hepatica was extracted with endoscopic retrograde cholangiography.

Ductal adenocarcinoma and unusual differential diagnosis; Duktales Adenokarzinom und ungewoehnliche Differenzialdiagnosen

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Haage, P.; Schwartz, C.A.; Scharwaechter, C. [Universitaet Witten/Herdecke, Zentrum fuer Radiologie HELIOS Universitaetsklinikum Wuppertal, Wuppertal (Germany)

2016-04-15

Ductal pancreatic adenocarcinoma is by far the most common solid tumor of the pancreas. It has a very poor prognosis, especially in the more advanced stages which are no longer locally confined. Due to mostly unspecific symptoms, imaging is key in the diagnostic process. Because of the widespread use of imaging techniques, incidental findings are to a greater extent discovered in the pancreas, which subsequently entail further work-up. Ductal pancreatic adenocarcinoma can be mimicked by a large number of different lesions, such as anatomical variants, peripancreatic structures and tumors, rarer primary solid pancreatic tumors, cystic tumors, metastases or different variants of pancreatitis. Additionally, a number of precursor lesions can be differentiated. The correct classification is thus important as an early diagnosis of ductal pancreatic adenocarcinoma is relevant for the prognosis and because the possibly avoidable treatment is very invasive. All major imaging techniques are principally suitable for pancreatic imaging. In addition to sonography of the abdomen, usually the baseline diagnostic tool, computed tomography (CT) with its superior spatial resolution, magnetic resonance imaging (MRI) with its good soft tissue differentiation capabilities, possibly in combination with MR cholangiopancreatography (MRCP), endosonography with its extraordinary spatial resolution, conceivably with additional endoscopic retrograde CP or the option of direct biopsy and finally positron emission tomography CT (PET-CT) as a molecular imaging tool are all particularly useful modalities. The various techniques all have its advantages and disadvantages; depending on the individual situation they may need to be combined. (orig.) [German] Das duktale Adenokarzinom ist der weitaus haeufigste solide Tumor des Pankreas. Die Prognose ist sehr schlecht, insbesondere bei fortgeschrittenen, nicht mehr lokal begrenzten Tumoren. Bei meist unspezifischen geringen Beschwerden kommt der

Low Alcohol and Cigarette Use Is Associated to the Risk of Developing Chronic Pancreatitis.

Science.gov (United States)

Di Leo, Milena; Leandro, Gioacchino; Singh, Satish K; Mariani, Alberto; Bianco, Margherita; Zuppardo, Raffaella Alessia; Goni, Elisabetta; Rogger, Teresa Marzia; Di Mario, Francesco; Guslandi, Mario; De Cobelli, Francesco; Del Maschio, Alessandro; Testoni, Pier Alberto; Cavestro, Giulia Martina

2017-02-01

The aim of this study was to investigate the contribution of smoking and alcohol intake and pancreas divisum on the risk of developing chronic pancreatitis (CP). Consecutive patients with CP who underwent secretin-enhanced magnetic resonance cholangiopancreatography were compared with consecutive patients without pancreatic disease who underwent secretin-enhanced magnetic resonance cholangiopancreatography for irritable bowel syndrome. We enrolled 145 consecutive CP patients and 103 irritable bowel syndrome patients from 2010 to 2014. In a univariate analysis, statistically significant differences in sex, mean age, and the duration and amount of cigarette and alcohol use were found. Per a receiver operating characteristic curve analysis, thresholds for cigarette and alcohol consumption were, respectively, 5.5 cigarettes and 13.5 g daily. In a multivariate analysis, independent risk factors for CP were male sex (odds ratio [OR], 2.05), smoking more than 5.5 cigarettes per day (OR, 2.72), and drinking more than 13.5 g/d (OR, 6.35). In an Italian population, we confirmed smoking and alcohol as cofactors in the development of CP. This study shows that alcohol intake and smoking habits are 2 of the most important risk factors for the development of CP.

Cholecystitis of a duplicated gallbladder complicated by a cholecystoenteric fistula

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Huang, Brady K. [University of Rochester Medical Center, Department of Imaging Sciences, Rochester, NY (United States); Chess, Mitchell A. [University of Rochester Medical Center, Department of Imaging Sciences, Rochester, NY (United States); Advanced Imaging, Batavia, NY (United States)

2009-04-15

Gallbladder duplications are uncommon anatomic variants that are sometimes mistaken for other entities on imaging. We present a surgically confirmed case of cholecystitis in a ductular-type duplicated gallbladder complicated by the formation of an inflammatory fistula to the adjacent duodenum. Both US and magnetic resonance cholangiopancreatography were performed preoperatively, in addition to intraoperative cholangiography, which confirmed the presence of a duplicated gallbladder. (orig.)

Surgeon-performed endoscopic retrograde cholangiopancreatography. Outcomes of 2392 procedures at two tertiary care centers.

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Al-Mansour, Mazen R; Fung, Eleanor C; Jones, Edward L; Zayan, Nichole E; Wetzel, Timothy D; Martin Del Campo, Sara E; Jalilvand, Anahita D; Suzo, Andrew J; Dettorre, Rebecca R; Fullerton, James K; Meara, Michael P; Mellinger, John D; Narula, Vimal K; Hazey, Jeffrey W

2018-06-01

Endoscopic retrograde cholangiopancreatography (ERCP) is a common procedure that, in the United States, is traditionally performed by gastroenterologists. We hypothesized that when performed by well-trained surgeons, ERCP can be performed safely and effectively. The objectives of the study were to assess the rate of successful cannulation of the duct of interest and to assess the 30-day complication and mortality rates. We retrospectively reviewed the charts of 1858 patients who underwent 2392 ERCP procedures performed by five surgeons between August 2003 and June 2016 in two centers. Demographic and historical data, indications, procedure-related data and 30-day complication and mortality data were collected and analyzed. The mean age was 53.4 (range 7-102) years and 1046 (56.3%) were female. 1430 (59.8%) of ERCP procedures involved a surgical endoscopy fellow. The most common indication was suspected or established uncomplicated common bile duct stones (n = 1470, 61.5%), followed by management of an existing biliary or pancreatic stent (n = 370, 15.5%) and acute biliary pancreatitis (n = 173, 7.2%). A therapeutic intervention was performed in 1564 (65.4%), a standard sphincterotomy in 1244 (52.0%), stent placement in 705 (29.5%) and stone removal in 638 (26.7%). When cannulation was attempted, the rate of successful cannulation was 94.1%. When cannulation was attempted during the patient's first ERCP the cannulation rate was 92.4%. 94 complications occurred (5.4%); the most common complication was post-ERCP pancreatitis in 75 (4.2%), significant gastrointestinal bleeding in 7 (0.4%), ascending cholangitis in 11 (0.6%) and perforation in 1 (0.05%). 11 mortalities occurred (0.5%) but none of which were ERCP-related. When performed by well-trained surgical endoscopists, ERCP is associated with high success rate and acceptable complication rates consistent with previously published reports and in line with societal guidelines.

Successful treatment of recurrent cholangitis by constructing a hepaticojejunostomy with long Roux-en-Y limb in a long-term surviving patient after a Whipple procedure for pancreatic adenocarcinoma.

Science.gov (United States)

Tsalis, Konstantinos; Antoniou, Nikolaos; Koukouritaki, Zambia; Patridas, Dimitrios; Sakkas, Leonidas; Kyziridis, Dimitrios; Lazaridis, Charalampos

2014-08-20

Female, 74. Recurrent cholangitis. -. -. -. Gastroenterology and Hepatology. Unusual clinical course. Cholangitis may result from biliary obstruction (e.g., biliary or anastomotic stenosis, or foreign bodies) or occur in the presence of normal biliary drainage. Although reflux of intestinal contents into the biliary tree after hepaticojejunostomy appears to be a rare complication, it is important to emphasize that there are few available surgical therapeutic techniques. A 74-year-old woman presented to our hospital after 17 years of episodes of cholangitis. The patient had undergone a pancreatoduodenectomy (Whipple procedure) 18 years earlier due to pancreatic adenocarcinoma. The reconstruction was achieved through the sequential placement of pancreatic, biliary, and retrocolic gastric anastomosis into the same jejunal loop. The postoperative course was uneventful and the patient received adjuvant chemotherapy. Approximately 6 months after the initial operation, the patient started having episodes of cholangitis. Over the next 17 years she experienced several febrile episodes presumed to be secondary to cholangitis. A computing tomography (CT) scan of the abdomen revealed intrahepatic bile ducts partially filled with orally administered contrast material (Gastrografin). Magnetic resonance cholangiopancreatography (MRCP) showed dilatation of the left intrahepatic bile ducts. A percutaneous transhepatic cholangiography showed that the bilioenteric anastomosis was normal, without stenosis. Based on these findings, a diagnosis of a short loop between the hepaticojejunostomy and the gastrojejunostomy permitting the reflux of intestinal juice into the biliary tree was made. During the re-operation, a new hepaticojejunal anastomosis in a 100-cm long Roux-en-Y loop was performed to prevent the reflux of the intestinal fluid into the biliary tree. The patient was discharged on postoperative day 10. One year after the second procedure, the patient enjoys good health and has

Influence of spontaneous rhythm on movement-related cortical potential

DEFF Research Database (Denmark)

Yao, Lin; Chen, Mei Lin; Sheng, Xinjun

2017-01-01

We have recently developed an associative Brain-Computer Interface (BCI) for neuromodulation in chronic and acute stroke patients that leads to functional improvements. The control signal is the movement related cortical potential (MRCP) that develops prior to movement execution. The MRCP increases...

Surgical Success in Chronic Pancreatitis: Sequential Endoscopic Retrograde Cholangiopancreatography and Surgical Longitudinal Pancreatojejunostomy (Puestow Procedure).

Science.gov (United States)

Ford, Kathryn; Paul, Anu; Harrison, Phillip; Davenport, Mark

2016-06-01

Introduction Chronic pancreatitis (CP) can be a cause of recurrent, severe, disabling abdominal pain in children. Surgery has been suggested as a useful therapy, although experience is limited and the results unpredictable. We reviewed our experience of a two-stage protocol-preliminary endoscopic retrograde cholangiopancreatography (ERCP) and duct stenting, and if symptoms resolved, definitive surgical decompression by longitudinal pancreatojejunostomy (LPJ) (Puestow operation). Patients and Methods This is a single-center, retrospective review of children with established CP who underwent an LPJ between February 2002 and September 2012. A questionnaire was completed (incorporating visual analog scale pain and lifestyle scores) to assess functional outcome. Data are expressed as median (range). Results In this study, eight (M:F ratio of 4:4) children underwent an LPJ and one female child had a more limited pancreatojejunostomy anastomosis following preliminary ERCP and stent placement where possible. Diagnoses included hereditary pancreatitis (n = 3), idiopathic or structural pancreatitis (n = 5), and duct stricture following radiotherapy (n = 1). Median duct diameter presurgery was 5 (4-11) mm. Endoscopic placement of a Zimmon pancreatic stent was possible in six with relief of symptoms in all. Median age at definitive surgery was 11 (range, 7-17) years with a median postoperative stay of 9 (range, 7-12) days and a follow-up of 6 (range, 0.5-12) years. All children reported markedly reduced episodes of pain postprocedure. One developed diabetes mellitus, while three had exocrine deficiency (fecal elastase Puestow operation was safe and complication-free with good medium-term relief of symptoms. We were not able to identify a consistent etiology-associated outcome. Georg Thieme Verlag KG Stuttgart · New York.

A comparison of ultrasound, computed tomography and endoscopic retrograde cholangiopancreatography in the differential diagnosis of benign and malignant jaundice and cholestasis

International Nuclear Information System (INIS)

Pasanen, P.A.; Alhava, E.M.; Partanen, K.P.; Pirinen, A.E.; Pikkarainen, P.H.; Janatuinen, E.K.

1993-01-01

To assess the accuracy of ultrasonography (US), computed tomography (CT), and endoscopic retrograde cholangiopancreatography (ERCP) in distinguishing between benign and malignant causes of jaundice and cholestasis without jaundice, a consecutive series of patients with jaundice or cholestasis without jaundice were studied. The most common benign disease was choledocholithiasis and the most common malignant disease was carcinoma of pancreas. The benign nature of the extrahepatic obstruction was correctly defined by US, CT, and ERCP in 53%, 53%, and 90% of patients, respectively, and the corresponding figure for choledocholithiasis were 22%, 25%, and 79%. Intrahepatic benign diseases were diagnosed by US and CT in a third of cases. Malignant extrahepatic obstruction was correctly diagnosed in 57%, 80%, and 83%, respectively and the corresponding figures for pancreatic cancer were 60%, 97% and 89%. Intrahepatic malignant lesions were diagnosed by US, CT, and ERCP in 100%, 77%, and 60% of patients, respectively. When the obstruction was benign and extrahepatic ERCP was the most accurate, but when it was malignant CT was comparable. Intrahepatic disease was best diagnosed by US and CT. The results emphasise that the three methods of imaging are complementary

Risk factors for pancreatic cancer and early diagnosis of pancreatic cancer

International Nuclear Information System (INIS)

Yamao, Kenji; Mizuno, Nobumasa; Sawaki, Akira; Shimizu, Yasuhiro; Chang, K.J.

2008-01-01

This paper describes the strategy for improving the poor prognosis of the pancreatic (P) cancer by its early imaging diagnosis followed by resection, based on recent findings on its high risk group. Epidemiological studies have revealed that patients with diabetes, chronic pancreatitis, intraductal papillary-mucious tumor, P cyst, familial history of P cancer, and hereditary P cancer syndrome are involved in the high risk group of P cancer. Imaging diagnosis with CT and/or endoscopic ultrasonography (EUS) followed by histological confirmation for resection can be a useful approach to improve the prognosis in those high risk, asymptomatic individuals with abnormal levels of P enzyme and tumor marker, and with US findings of P ductal dilation and cyst. The guideline 2006 for P cancer by Japan Pancreas Society shows the algorithm leading to the final diagnosis for the positive high risk group: firstly, CT and/or MRCP (MR cholangiopancreatography (CP)); or, in case of uncertainty, EUS and/or ERCP (E retrograde CP) and/or PET; and finally, cytological, histological diagnosis. The newer approach proposed recently for the group is: multi detector row (MD)-CT and EUS; then cytodiagnosis guided by ERCP and/or with fine needle aspiration by EUS, also a promising early diagnosis. As well, molecular biological approaches are supposedly useful for the future diagnosis. (R.T.)

Diagnosis and management of pancreaticopleural fistula.

Science.gov (United States)

Tay, Clifton Ming; Chang, Stephen Kin Yong

2013-04-01

Pancreaticopleural fistula is a rare diagnosis requiring a high index of clinical suspicion due to the predominant manifestation of thoracic symptoms. The current literature suggests that confirmation of elevated pleural fluid amylase is the most important diagnostic test. Magnetic resonance cholangiopancreatography is the recommended imaging modality to visualise the fistula, as it is superior to both computed tomography and endoscopic retrograde cholangiopancreatography (ERCP) in delineating the tract within the pancreatic region. It is also less invasive than ERCP. While a trial of medical regimen has traditionally been the first-line treatment, failure would result in higher rates of complications. Hence, it is suggested that management strategies be planned based on pancreatic ductal imaging, with patients having poor chances of spontaneous closure undergoing either endoscopic or surgical intervention. We also briefly describe a case of pancreaticopleural fistula in a patient who was treated using a modified Puestow procedure after failed endoscopic treatment.

Laparoendoscopic rendezvous may be an effective alternative to a failed preoperative endoscopic retrograde cholangiopancreatography in patients with cholecystocholedocholithiasis.

Science.gov (United States)

Tsiopoulos, Fotios; Kapsoritakis, Andreas; Psychos, Athanassios; Manolakis, Anastasios; Oikonomou, Konstantinos; Tzovaras, George; Baloyiannis, Ioannis; Tsikrika, Alexandra; Potamianos, Spyros

2018-01-01

Endoscopic retrograde cholangiopancreatography (ERCP), followed by laparoscopic cholecystectomy (LC), remains the standard way of management for patients with cholecystocholedocholithiasis. Laparoendoscopic rendezvous (LERV), a combined procedure for removing the gallbladder laparoscopically and clearing the common bile duct (CBD) endoscopically at the same time, could be an attractive alternative. The aim of this study was to compare LERV with classic ERCP in patients with cholecystocholedocholithiasis. 886 patients with cholecystocholedocholithiasis were treated either with the LERV technique (90 patients), or with the 2-stage approach, which includes preoperative ERCP followed by LC (796 patients). The primary endpoint was any difference in the success of CBD cannulation and clearance; secondary endpoints were the detection of differences in morbidity (especially post-ERCP pancreatitis [PEP]), and the feasibility of the two approaches. Successful cannulation of the CBD was more frequent with conventional ERCP compared with the LERV technique (89.8% vs. 75.5%, P=0.0001). LERV appears to be as effective as conventional ERCP for complete CBD clearance (85.5% vs. 82.8%, P<0.1). None of the patients in the LERV group had an episode of clinical PEP, whereas in the conventional ERCP group there were 23 episodes of PEP and one death. The median amylase level was higher in patients undergoing conventional ERCP group compared to patients in LERV group. Classic ERCP has a higher rate of successful CBD cannulation and a similar rate of CBD clearance compared to LERV.

Efficiency and Safety of One-Step Procedure Combined Laparoscopic Cholecystectomy and Eretrograde Cholangiopancreatography for Treatment of Cholecysto-Choledocholithiasis: A Randomized Controlled Trial.

Science.gov (United States)

Liu, Zhiyi; Zhang, Luyao; Liu, Yanling; Gu, Yang; Sun, Tieliang

2017-11-01

We aimed to evaluate the efficiency and safety of one-step procedure combined endoscopic retrograde cholangiopancreatography (ERCP) and laparoscopic cholecystectomy (LC) for treatment of patients with cholecysto-choledocholithiasis. A prospective randomized study was performed on 63 consecutive cholecysto-choledocholithiasis patients during 2008 and 2011. The efficiency and safety of one-step procedure was assessed by comparing the two-step LC with ERCP + endoscopic sphincterotomy (EST). Outcomes including intraoperative features, postoperative features (length of stay and postoperative complications) were evaluated. One- or two-step procedure of LC with ERCP + EST was successfully performed in all patients, and common bile duct stones were completely removed. Statistical analyses showed that length of stay and pulmonary infection rate were significantly lower in the test group compared with that in the control group (P 0.05). The one-step procedure of LC with ERCP + EST is superior to the two-step procedure for treatment of patients with cholecysto-choledocholithiasis regarding to the reduced hospital stay and inhibited occurrence of pulmonary infections. Compared with two-step procedure, one-step procedure of LC with ERCP + EST may be a superior option for cholecysto-choledocholithiasis patients treatment regarding to hospital stay and pulmonary infections.

Hepatoduodenal lymph node metastasis mimicking Klatskin tumor in a patient with sigmoid colon mucinous cancer

Directory of Open Access Journals (Sweden)

Hovhannes Vardevanyan, PhD

2017-09-01

Full Text Available We report a case of a 48-year-old female patient, who presented with abdominal pain, jaundice, and lack of appetite. Ultrasound showed intrahepatic biliary dilatation with retroperitoneal lymphadenopathy. Further magnetic resonance cholangiopancreatography detected Klatskin tumor. Computed tomography (CT confirmed the Klatskin tumor with liver metastases and retroperitoneal lymphadenopathy. Biopsy from the hepatic lesion identified mucinous adenocarcinoma, likely originating from bile ducts. Endoscopic retrograde cholangiopancreatography was performed 3 times with stents placed in the left and right hepatic bile ducts. Later the patient had hematochezia and was referred to colonoscopy. Tubulovillous adenoma with dysplasia was diagnosed with signs of in situ cancer. Preoperative CT was done for further staging: new pulmonary metastases were discovered. Sigmoid colon was resected. Histopathology verified a poorly differentiated mucinous adenocarcinoma within the tubulovillous adenoma. Intraoperative biopsies of porta hepatis mass resembled metastatic lymph nodes in hepatoduodenal ligament, mimicking Klatskin tumor. Retrospective analysis of CT data demonstrated presence of sigmoid colon tumor.

Evolving Role of Endoscopic Retrograde Cholangiopancreatography in Management of Extrahepatic Hepatic Ductal Injuries due to Blunt Trauma: Diagnostic and Treatment Algorithms

Directory of Open Access Journals (Sweden)

Nikhil P. Jaik

2008-01-01

Full Text Available Extrahepatic hepatic ductal injuries (EHDIs due to blunt abdominal trauma are rare. Given the rarity of these injuries and the insidious onset of symptoms, EHDI are commonly missed during the initial trauma evaluation, making their diagnosis difficult and frequently delayed. Diagnostic modalities useful in the setting of EHDI include computed tomography (CT, abdominal ultrasonography (AUS, nuclear imaging (HIDA scan, and cholangiography. Traditional options in management of EHDI include primary ductal repair with or without a T-tube, biliary-enteric anastomosis, ductal ligation, stenting, and drainage. Simple drainage and biliary decompression is often the most appropriate treatment in unstable patients. More recently, endoscopic retrograde cholangiopancreatography (ERCP allowed for diagnosis and potential treatment of these injuries via stenting and/or papillotomy. Our review of 53 cases of EHDI reported in the English-language literature has focused on the evolving role of ERCP in diagnosis and treatment of these injuries. Diagnostic and treatment algorithms incorporating ERCP have been designed to help systematize and simplify the management of EHDI. An illustrative case is reported of blunt traumatic injury involving both the extrahepatic portion of the left hepatic duct and its confluence with the right hepatic duct. This injury was successfully diagnosed and treated using ERCP.

A rare case of suprahepatic gall bladder with phocomelia and pancytopenia: detected by tc-99m mebrofenin scintigraphy.

Science.gov (United States)

Rather, Tanveeer Ah; Khan, Shoukat H; Singh, Manjeet; Choh, Naseer A

2013-01-01

The possibility of an ectopic gallbladder should always be considered whenever there is a failure to localize it in its normal anatomical position on routine imaging. Although a very rare entity, the anomalous position of gallbladder can result in misinterpretation of imaging findings and create clinical confusion. Awareness of such an anomaly facilitates proper diagnosis and subsequent management. The authors report a very rare case of suprahepatic gallbladder associated with phocomelia, pancytopenia, and splenomegaly in a young 25-year-old female. The suprahepatic gallbladder was initially visualized on Technetium-99m (Tc-99m) Mebrofenin radionuclide hepatobiliary scintigraphy. Subsequent magnetic resonance cholecystopancreatography (MRCP) was also done to confirm the diagnosis.

A Rare Case of Suprahepatic Gall Bladder with Phocomelia and Pancytopenia: Detected by Tc-99m Mebrofenin Scintigraphy

International Nuclear Information System (INIS)

Rather, Tanveeer Ah; Khan, Shoukat H.; Singh, Manjeet; Choh, Naseer A.

2013-01-01

The possibility of an ectopic gallbladder should always be considered whenever there is a failure to localize it in its normal anatomical position on routine imaging. Although a very rare entity, the anomalous position of gallbladder can result in misinterpretation of imaging findings and create clinical confusion. Awareness of such an anomaly facilitates proper diagnosis and subsequent management. The authors report a very rare case of suprahepatic gallbladder associated with phocomelia, pancytopenia, and splenomegaly in a young 25-year-old female. The suprahepatic gallbladder was initially visualized on Technetium-99m (Tc-99m) Mebrofenin radionuclide hepatobiliary scintigraphy. Subsequent magnetic resonance cholecystopancreatography (MRCP) was also done to confirm the diagnosis

The Antistreptolysin Titre Diagnostic Index (ASO Titre) Hepatitis as a

African Journals Online (AJOL)

N. GITLIN, M.B., CH.B., M.R.C.P, (LOND.), M.R.C.P. (EDlN.) AA'D 1. R. DOWDESWELL, M.B., CH.B.,. Liver Clinic, Groote Schuur Hospital and Department of Medicine and Liver Research Group, University of Cape Town, O. L. MEYERS, M.B., CH.B., F.C.P. (S.A.), Immunology Laboratory, Department of Medi- cine, University ...

Pancreatico-pleural Fistula: Case Series

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Manoj Munirathinam

2018-01-01

Full Text Available Pancreatico-pleural fistula is a rare but serious complication of acute and chronic pancreatitis. The pleural effusion caused by pancreatico-pleural fistula is usually massive and recurrent. It is predominately left-sided but right-sided and bilateral effusion does occur. We report four cases of pancreatico-pleural fistula admitted to our hospital. Their clinical presentation and management aspects are discussed. Two patients were managed by pancreatic endotherapy and two patients were managed conservatively. All four patients improved symptomatically and were discharged and are on regular follow-up. Most of these patients would be evaluated for their breathlessness and pleural effusion delaying the diagnosis of pancreatic pathology and management. Hence, earlier recognition and prompt treatment would help the patients to recover from their illnesses. Pancreatic pleural fistula diagnosis requires a high index of suspicion in patients presenting with chest symptoms or pleural effusion. Extremely high pleural fluid amylase levels are usual but not universally present. A chest X-ray, pleural fluid analysis, and abdominal imaging (magnetic resonance cholangiopancreatography/magnetic resonance imaging abdomen more useful than contrast-enhanced computed tomography abdomen would clinch the diagnosis. Endoscopic retrograde cholangiopancreatography with stent or sphincterotomy should be considered when pancreatic duct (PD reveals a stricture or when medical management fails in patients with dilated or irregular PD. Surgical intervention may be indicated in patients with complete disruption of PD or multiple strictures.

Rutinemaessig endoskopisk retrograd kolangiopankreatikografi kan ikke anbefales ved galdestenspankreatitis

DEFF Research Database (Denmark)

Ainsworth, Alan Patrick; Svendsen, Lars Bo

2009-01-01

Danish guidelines recommend that patients with presumed severe gallstone-induced acute pancreatitis (GAP) should receive endoscopic retrograde cholangiopancreatography (ERCP) within 72 hours. The results of a newly performed meta-analysis show that acute ERCP in patients with GAP does not reduce...... the risk of complications, and ERCP is therefore not to be used routinely in GAP patients. The possible benefits of replacing ERCP with either endoscopic ultrasonography or magnetic resonance cholangiopancreatograhy have yet to be demonstrated. Udgivelsesdato: 2009-Aug-31...

75 r:t

African Journals Online (AJOL)

1971-01-16

Jan 16, 1971 ... The over-all standard of the reproductions and printing is outstanding, and I have no hesitation in recommending that ... visers in the Pharmaceutical Industry. Ed. by E. L. Harris. M.B., B.Ch., M.R.C.P., M.R.C.P. ... Industry (Great Britain) in February 1969. The work is inter- esting on 2 counts. Firstly it is a clear ...

Urgent endoscopic retrograde cholangiopancreatography is not superior to early ERCP in acute biliary pancreatitis with biliary obstruction without cholangitis.

Science.gov (United States)

Lee, Hee Seung; Chung, Moon Jae; Park, Jeong Youp; Bang, Seungmin; Park, Seung Woo; Song, Si Young; Chung, Jae Bock

2018-01-01

Acute pancreatitis is a common diagnosis worldwide, with gallstone disease being the most prevalent cause (50%). The American College of Gastroenterology recommends urgent endoscopic retrograde cholangiopancreatography (ERCP) (within 24 h) for patients with biliary pancreatitis accompanied by cholangitis. Most international guidelines recommend that ERCP be performed within 72 h in patients with biliary pancreatitis and a bile duct obstruction without cholangitis, but the optimal timing for endoscopy is controversial. We investigated the optimal timing for ERCP in patients with biliary pancreatitis and a bile duct obstruction without cholangitis, and whether performing endoscopy within 24 h is superior to performing it after 24 h. We analyzed the clinical data of 505 patients with newly diagnosed acute pancreatitis, from January 1, 2005 to December 31, 2014. We divided the patients into two groups according to the timing of ERCP: pancreatitis and a bile duct obstruction without cholangitis. The mean age of the patients was 55 years (range: 26-90 years). Bile duct stones and biliary sludge were identified on endoscopy in 45 (61.6%) and 11 (15.0%) patients, respectively. The timing of ERCP within 72 h was not associated with ERCP-related complications (P = 0.113), and the total length of hospital stay was not different between urgent and early ERCP (5.9 vs. 5.7 days, P = 0.174). No significant differences were found in total length of hospitalization or procedural-related complications, in patients with biliary pancreatitis and a bile duct obstruction without cholangitis, according to the timing of ERCP (< 24 h vs. 24-72 h).

Primary non-Hodgkin's lymphoma of the common bile duct: A case report and literature review

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Ali Zakaria

2017-01-01

Full Text Available Hepatobiliary involvement by malignant lymphoma is usually a secondary manifestation of systemic disease, whereas primary non-Hodgkin's lymphoma of the extrahepatic biliary ducts is an extremely rare entity. We describe the case of a 57-year-old man who presented with an acute onset of obstructive jaundice and severe itching. Abdominal ultrasonography and computed tomography revealed intrahepatic and common hepatic ducts dilatation. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography showed a mid-common bile duct stricture. The patient was presumed to have cholangiocarcinoma of the common bile duct, and an en bloc resection of the tumor with Roux-en-Y hepaticojejunostomy and porta-hepatis lymph nodes dissection was performed. Histopathology and immunohistochemistry revealed a large B cell non-Hodgkin's lymphoma. The patient received six cycles of combination chemotherapy using cyclophosphamide, vincristine, prednisone, and rituximab (CVP-R protocol, and after a 5-year follow-up he is still in complete remission. We also reviewed the cases published from 1982 to 2012, highlighting the challenges in reaching a correct preoperative diagnosis and the treatment modalities used in each case.

Clinical usefulness of a short-type, prototype single-balloon enteroscope for endoscopic retrograde cholangiopancreatography in patients with altered gastrointestinal anatomy: preliminary experiences.

Science.gov (United States)

Kawamura, Takuji; Uno, Koji; Suzuki, Azumi; Mandai, Koichiro; Nakase, Kojiro; Tanaka, Kiyohito; Yasuda, Kenjiro

2015-01-01

A limited number of endoscopic retrograde cholangiopancreatography (ERCP) accessories are compatible with the conventional single-balloon enteroscope (SBE) because of the latter's dimensions. The aim of the present study was to assess the utility of a prototype SBE that has a shorter working length and a wider channel than the conventional SBE. ERCP procedures carried out between January 2012 and July 2013 using the short SBE prototype were reconstructions such as Billroth II (B-II), post-gastrectomy with Roux-en-Y (RY-G), and post-choledochojejunostomy with Roux-en-Y (RY-CJ). We retrospectively analyzed the rate of reaching the blind end of the intestine, the diagnostic success rate, the interventional success rate, and the frequency of related complications. Twenty-seven ERCP procedures on 18 patients analyzed comprised two B-II, 15 RY-G, and 10 RY-CJ reconstructions. With a mean procedure time of 56 min (range 40-150 min), the rate of reaching the blind end, the diagnostic success rate, and the interventional success rate were 24/27 (89%), 20/27 (74%), and 19/27 (70%), respectively. There were no major ERCP-related complications in any patient. The prototype short-type SBE appears safe and effective for use in ERCP, and is compatible with conventional endoscopy accessories. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.

MRI and MRCP of chronic pancreatitis. 1: technique and methods; La valutazione delle pancreatiti croniche con Risonanza Magnetica e colangiopancreatografia con Risonanza Magnetica. Prima parte: aspetti tecnico-metodologici

Energy Technology Data Exchange (ETDEWEB)

Laghi, A.; Pavone, P.; Catalano, C.; Panebianco, V.; Luccichenti, G.; Fabiano, S.; Passariello, R. [Rome Univ. La Sapienza, Rome (Italy). Ist. di Radiologia

1999-10-01

Until recently, MR examinations of the pancreas were limited by motion artifacts, vascular pulsatility and poor spatial resolution. Today, new techniques have been developed, which allow to overcome these problems and provide additional information such as selective images of biliary and pancreatic ducts and vascular structures. As a complement to baseline sequences, MR cholangiopancreatography images can be acquired, possibly integrated by functional examination after secretin administration. Finally, contrast-enhanced MR angiography opens new perspectives for vascular studies, particularly for the locoregional staging of pancreatic cancer. [Italian] Lo studio del pancreas con risonanza magnetica e' stato fino a pochi anni fa limitato dagli artefatti da movimento, da pulsatilita' vascolare e dalla ridotta risoluzione spaziale. Recentemente sono state sviluppate nuove tecniche che consentono da un lato di risolvere tali problemi e dall'altro di fornire informazioni aggiuntive, quali immagini selettive delle vie biliari e del dotto pancreatico e delle strutture vascolari. Come completamento all'esame di base si possono ottenere immagini di colangiopancreatografia con RM, eventualmente integrate da prove funzionali, rappresentate dall'iniezione di secretina. Infine, le nuove tecniche di angiografia con RM con mdc, nelle quali si effettua un'acquisizione durante la prima fase di passaggio arterioso o venoso dopo introduzione rapida del mdc a livello di una vena periferica, aprono nuove prospettive per lo studio vascolare, in particolare nella stadiazione loco-regionale dei processi neoplastici.

Resonances, resonance functions and spectral deformations

International Nuclear Information System (INIS)

Balslev, E.

1984-01-01

The present paper is aimed at an analysis of resonances and resonance states from a mathematical point of view. Resonances are characterized as singular points of the analytically continued Lippman-Schwinger equation, as complex eigenvalues of the Hamiltonian with a purely outgoing, exponentially growing eigenfunction, and as poles of the S-matrix. (orig./HSI)

Measuring the value of endoscopic retrograde cholangiopancreatography activity: an opportunity to stratify endoscopists on the basis of their value.

Science.gov (United States)

Parihar, Vikrant; Moran, Carthage; Maheshwari, Pardeep; Cheriyan, Danny; O'Toole, Aoibhlinn; Murray, Frank; Patchett, Stephen E; Harewood, Gavin C

2018-07-01

As finite healthcare resources come under pressure, the value of physician activity is assuming increasing importance. The value in healthcare can be defined as patient health outcomes achieved per monetary unit spent. Even though some attempts have been made to quantify the value of clinician activity, there is little in the medical literature describing the importance of endoscopists' activity. This study aimed to characterize the value of endoscopic retrograde cholangiopancreatography (ERCP) performance of five gastroenterologists. We carried out a retrospective-prospective cohort study using the databases of patients undergoing ERCP between September 2014 and March 2017. We collected data from 1070 patients who underwent ERCP comparing value among the ERCPists at index ERCP. Procedure value was calculated using the formula Q/(T/C), where Q is the quality of procedure, T is the duration of procedure and C is the adjusted for complexity level. Quality and complexity were derived on a 1-4 Likert scale on the basis of American Society for Gastrointestinal Endoscopy criteria; time was recorded (in min) from intubation to extubation. Endoscopist time calculated from procedure time was considered a surrogate marker of cost as individual components of procedure cost were not itemized. In total, 590 procedures were analysed: 465 retrospectively over 24 months and 125 prospectively over 6 months. There was a 32% variation in the value of endoscopist activity in a more substantial retrospective cohort, with an even more considerable 73% variation in a smaller prospective arm. In an analysis of greater than 1000 ERCPs by a small cohort of experienced ERCPists, there was a wide variation in the value of endoscopist activity. Although the precision of estimating procedural costs needs further refinement, these findings show the ability to stratify ERCPists on the basis of the value their activity. As healthcare costs are scrutinized more closely, such value measurements are

Rationale diagnostic approach to biliary tract imaging

International Nuclear Information System (INIS)

Helmberger, H.; Huppertz, A.; Ruell, T.; Zillinger, C.; Ehrenberg, C.; Roesch, T.

1998-01-01

Since the introduction of MR cholangiography (MRC) diagnostic imaging of the biliary tract has been significantly improved. While percutaneous ultrasonography is still the primary examination, computed tomography (CT), conventional magnetic resonance imaging (MRI), as well as the direct imaging modalities of the biliary tract - iv cholangiography, endoscopic-retrograde-cholangiography (ERC), and percutaneous-transhepatic-cholangiography (PTC) are in use. This article discusses the clinical value of the different diagnostic techniques for the various biliary pathologies with special attention to recent developments in MRC techniques. An algorithm is presented offering a rational approach to biliary disorders. With further technical improvement shifts from ERC(P) to MRC(P) for biliary imaging could be envisioned, ERCP further concentrating on its role as a minimal invasive treatment option. (orig.) [de

Efficient primary and parametric resonance excitation of bistable resonators

KAUST Repository

Ramini, Abdallah

2016-09-12

We experimentally demonstrate an efficient approach to excite primary and parametric (up to the 4th) resonance of Microelectromechanical system MEMS arch resonators with large vibrational amplitudes. A single crystal silicon in-plane arch microbeam is fabricated such that it can be excited axially from one of its ends by a parallel-plate electrode. Its micro/nano scale vibrations are transduced using a high speed camera. Through the parallel-plate electrode, a time varying electrostatic force is applied, which is converted into a time varying axial force that modulates dynamically the stiffness of the arch resonator. Due to the initial curvature of the structure, not only parametric excitation is induced, but also primary resonance. Experimental investigation is conducted comparing the response of the arch near primary resonance using the axial excitation to that of a classical parallel-plate actuation where the arch itself forms an electrode. The results show that the axial excitation can be more efficient and requires less power for primary resonance excitation. Moreover, unlike the classical method where the structure is vulnerable to the dynamic pull-in instability, the axial excitation technique can provide large amplitude motion while protecting the structure from pull-in. In addition to primary resonance, parametrical resonances are demonstrated at twice, one-half, and two-thirds the primary resonance frequency. The ability to actuate primary and/or parametric resonances can serve various applications, such as for resonator based logic and memory devices. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license

Cyclotron resonance for electrons over helium in resonator

CERN Document Server

Shikin, V B

2002-01-01

The problem on the cyclotron resonance (CR) for electrons on the helium film, positioned in the resonator lower part, is solved. It is shown, that it relates to one of the examples of the known problem on the oscillations of the coupled oscillators system. The coupling constant between these oscillators constituting the variable function of the problem parameters. It is minimal in the zero magnetic field and reaches its maximum under the resonance conditions, when the cyclotron frequency coincides with one of the resonator modes. The CR details of the Uhf CR-energy absorption coupled by the electrons + resonator system, are calculated. The applications of the obtained results to the available CR experiments for electrons over helium

Microstrip resonators for electron paramagnetic resonance experiments

Science.gov (United States)

Torrezan, A. C.; Mayer Alegre, T. P.; Medeiros-Ribeiro, G.

2009-07-01

In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5×1010 spins/GHz1/2 despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.

Microstrip resonators for electron paramagnetic resonance experiments.

Science.gov (United States)

Torrezan, A C; Mayer Alegre, T P; Medeiros-Ribeiro, G

2009-07-01

In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5 x 10(10) spins/GHz(1/2) despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.

Multiphoton resonances

International Nuclear Information System (INIS)

Shore, B.W.

1977-01-01

The long-time average of level populations in a coherently-excited anharmonic sequence of energy levels (e.g., an anharmonic oscillator) exhibits sharp resonances as a function of laser frequency. For simple linearly-increasing anharmonicity, each resonance is a superposition of various multiphoton resonances (e.g., a superposition of 3, 5, 7, . . . photon resonances), each having its own characteristic width predictable from perturbation theory

Prevention effect of allopurinol on post-endoscopic retrograde cholangiopancreatography pancreatitis: a meta-analysis of prospective randomized controlled trials.

Directory of Open Access Journals (Sweden)

Wei-Li Cao

Full Text Available BACKGROUND: Pancreatitis is the most common complication of endoscopic retrograde cholangiopancreatography (ERCP which can be severe and cause death in approximately 10% of cases. Up to now, six randomized controlled trials (RCTs have been found relevant to the effect of allopurinol on prevention of Post-ERCP pancreatitis (PEP. However, these results remained controversial. OBJECTIVE: To conduct a meta-analysis with RCTs published in full text to determine the effectiveness of prophylactic allopurinol of different dosages and administration time in the incidence and severity of PEP. METHODS: Literature search was performed in PubMed, Embase, Web of Science and Cochrane Library from databases inception to May 2014. RCTs comparing the effect of allopurinol with placebo on prevention of PEP were included. Statistical heterogeneity was quantitatively evaluated byχ2 test with the significance set P50%. RESULTS: Six RCTs consisting of 1974 participants were eventually included. The incidences of PEP in allopurinol group and placebo group were 8.4%(83/986 and 9.9%(98/988 respectively. Meta-analysis showed no evident prevention effect of allopurinol on the incidence of PEP (RR 0.75, 95%CI 0.39-1.42 with significant heterogeneity (I2 = 70.4%, P = 0.005. When studies were stratified according to the dosages and administration time of allopurinol they applied, there was still no evident prevention effect of allopurinol on mild, moderate or severe PEP. However, statistically substantial heterogeneity was presented in the subgroup of moderate PEP when the effect of high dose of allopurinol was analyzed (Imoderate2 = 82.3%, Pmoderate = 0.018. Statistically significant heterogeneity was also observed in subgroup of mild PEP, when the effect of long adminstration time of allopurinol was investigated (Imild2 = 62.8%, Pmild = 0.068. CONCLUSION: The prophylactic use of allopurinol in different dosages and administration time had no effect

Magnetic resonance annual 1986

International Nuclear Information System (INIS)

Kressel, H.Y.

1986-01-01

This book contains papers written on magnetic resonance during 1986. Topics include: musculosketetal magnetic resonance imaging; imaging of the spine; magnetic resonance chemical shift imaging; magnetic resonance imaging in the central nervous system; comparison to computed tomography; high resolution magnetic resonance imaging using surface coils; magnetic resonance imaging of the chest; magnetic resonance imaging of the breast; magnetic resonance imaging of the liver; magnetic resonance spectroscopy of neoplasms; blood flow effects in magnetic resonance imaging; and current and potential applications of clinical sodium magnetic resonance imaging

Diagnostic Dilemma in a Patient with Jaundice: How to Differentiate between Autoimmune Pancreatitis, Primary Sclerosing Cholangitis and Pancreas Carcinoma

Directory of Open Access Journals (Sweden)

Matthias Buechter

2012-04-01

Full Text Available A 68-year-old male patient was referred to our institution in May 2011 for a suspected tumor in the pancreatic head with consecutive jaundice. Using magnetic resonance imaging, further differentiation between chronic inflammation and a malignant process was not possible with certainty. Apart from cholestasis, laboratory studies showed increased values for CA 19-9 to 532 U/ml (normal <37 U/ml and hypergammaglobulinemia (immunoglobulin G, IgG of 19.3% (normal 8.0–15.8% with an elevation of the IgG4 subtype to 2,350 mg/l (normal 52–1,250 mg/l. Endoscopic retrograde cholangiopancreatography revealed a prominent stenosis of the distal ductus hepaticus communis caused by pancreatic head swelling and also a bihilar stenosis of the main hepatic bile ducts. Cytology demonstrated inflammatory cells without evidence of malignancy. Under suspicion of autoimmune pancreatitis with IgG4-associated cholangitis, immunosuppressive therapy with steroids and azathioprine was started. Follow-up endoscopic retrograde cholangiopancreatography after 3 months displayed regressive development of the diverse stenoses. Jaundice had disappeared and blood values had returned to normal ranges. Moreover, no tumor of the pancreatic head was present in the magnetic resonance control images. Due to clinical and radiological similarities but a consecutive completely different prognosis and therapy, it is of fundamental importance to differentiate between pancreatic cancer and autoimmune pancreatitis. Especially, determination of serum IgG4 levels and associated bile duct lesions induced by inflammation should clarify the diagnosis of autoimmune pancreatitis and legitimate immunosuppressive therapy.

Single- and double-balloon enteroscopy-assisted endoscopic retrograde cholangiopancreatography in patients with Roux-en-Y plus hepaticojejunostomy anastomosis and Whipple resection.

Science.gov (United States)

Itokawa, Fumihide; Itoi, Takao; Ishii, Kentaro; Sofuni, Atsushi; Moriyasu, Fuminori

2014-04-01

In patients with Roux-en-Y hepaticojejunostomy (HJ with R-Y) and Whipple resection, endoscopic retrograde cholangiopancreatography (ERCP) can be challenging. We report our experience with ERCP using balloon-assisted enteroscopy (BAE) (BAE-ERCP) in patients with HJ with R-Y, and Whipple resection. BAE-ERCP procedures were carried out in 62 patients (HJ with R-Y:Whipple resection=34:28). Overall, the rates of reaching the anastomosis were 85.3% (29/34) in HJ with R-Y and 96.4% (27/28) in Whipple resection. In terms of HJ with R-Y, insertion success rate by standard single-balloon enteroscopy (SBE) was 89.3% (25/28). Insertion success rate by short BAE, including SBE and double-balloon enteroscopy (DBE), was 50% (3/6). There was a statistically significant difference of insertion success rate between standard long BE and short BE (P=0.021). However, in the Whipple patients, insertion success rate by standard and short SBE was 93.8% (15/16) and 91.7% (11/12), respectively. Initial insertion success rate by short BAE in Whipple patients was significantly higher than in HJ with R-Y (91.7% vs 50%, P=0.045). Therapeutic interventions included dilation of anastomosis stricture, stone extraction, endoscopic mechanical lithotripsy, biliary stent placement, stent extraction, endoscopic nasobiliary drainage, direct cholangioscopy, and electrohydraulic lithotripsy. Our HJ with R-Y series and Whipple series treatment success rate was 90% (18/20) and 95.0% (19/20), respectively. BAE-ERCP enabled ERCP to be carried out in patients with HJ. It is considered safe and feasible. Further experience and device improvement are needed. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.

Effects of melatonin on the acute inflammatory response associated with endoscopic retrograde cholangiopancreatography: A randomized, double-blind, placebo-controlled trial.

Science.gov (United States)

Hernández-Velázquez, B; Camara-Lemarroy, C R; González-González, J A; García-Compean, D; Monreal-Robles, R; Cordero-Pérez, P; Muñoz-Espinosa, L E

2016-01-01

Endoscopic retrograde cholangiopancreatography (ERCP) is associated with an acute inflammatory response and melatonin has a variety of immunomodulatory and antioxidant effects studied experimentally in pancreatobiliary pathology. The aim of our study was to evaluate the effects of peri-procedural administration of melatonin on the inflammatory response and lipid peroxidation associated with ERCP. In this proof-of-concept clinical trial, 37 patients with a high probability of choledocholithiasis were randomized to receive peri-procedure (ERCP) melatonin or placebo. We measured the serum concentration of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), lipid peroxidation, amylase, and liver function tests 24h before and after the procedure. We found no pre-procedure or post-procedure differences between the melatonin group or the placebo group (P>.05) in the serum concentrations of TNF-alpha (melatonin: 153.8 vs. 149.4ng/m; placebo: 103.5 vs. 107.3ng/ml), IL-6 (melatonin: 131.8 vs. 133.3ng/ml; placebo: 177.8 vs. 197.8ng/ml), or VEGF (melatonin: 157.3 vs. 157.8pg/ml; placebo: 97.3 vs. 97.8pg/ml), or in relation to lipid peroxidation (melatonin: 39.2 vs. 72.3μg/ml; placebo: 66.4 vs. 90.5μg/ml). After ERCP, a significant decrease in the AST, ALT, and total bilirubin levels was found only in the melatonin group (P<.05). The administration of melatonin was safe and tolerable. Melatonin is safe and tolerable in patients undergoing ERCP, but it does not appear to affect inflammatory cytokine concentrations or lipid peroxidation. Copyright © 2016 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

Comparison of different magnetic resonance cholangiography techniques in living liver donors including Gd-EOB-DTPA enhanced T1-weighted sequences.

Directory of Open Access Journals (Sweden)

Sonja Kinner

Full Text Available Preoperative evaluation of potential living liver donors (PLLDs includes the assessment of the biliary anatomy to avoid postoperative complications. Aim of this study was to compare T2-weighted (T2w and Gd-EOB-DTPA enhanced T1-weighted (T1w magnetic resonance cholangiography (MRC techniques in the evaluation of PLLDs.30 PLLDs underwent MRC on a 1.5 T Magnetom Avanto (Siemens, Erlangen, Germany using (A 2D T2w HASTE (Half Fourier Acquisition Single Shot Turbo Spin Echo fat saturated (fs in axial plane, (B 2D T2w HASTE fs thick slices in coronal plane, (C free breathing 3D T2w TSE (turbo spin echo RESTORE (high-resolution navigator corrected plus (D maximum intensity projections (MIPs, (E T2w SPACE (sampling perfection with application optimized contrasts using different flip angle evolutions plus (F MIPs and (G T2w TSE BLADE as well as Gd-EOB-DTPA T1w images without (G and with (H inversion recovery. Contrast enhanced CT cholangiography served as reference imaging modality. Two independent reviewers evaluated the biliary tract anatomy on a 5-point scale subjectively and objectively. Data sets were compared using a Mann-Whitney-U-test. Kappa values were also calculated.Source images and maximum intensity projections of 3D T2w TSE sequences (RESTORE and SPACE proved to be best for subjective and objective evaluation directly followed by 2D HASTE sequences. Interobserver variabilities were good to excellent (k = 0.622-0.804.3D T2w sequences are essential for preoperative biliary tract evaluation in potential living liver donors. Furthermore, our results underline the value of different MRCP sequence types for the evaluation of the biliary anatomy in PLLDs including Gd-EOB-DTPA enhanced T1w MRC.

996 RESONANCE November 2013

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Pancreaticopleural Fistula Causing Massive Right Hydrothorax and Respiratory Failure

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Esther Ern-Hwei Chan

2016-01-01

Full Text Available Hydrothorax secondary to a pancreaticopleural fistula (PPF is a rare complication of acute pancreatitis. In patients with a history of pancreatitis, diagnosis is made by detection of amylase in the pleural exudate. Imaging, particularly magnetic resonance cholangiopancreatography, aids in the detection of pancreatic ductal disruption. Management includes thoracocentesis and pancreatic duct drainage or pancreatic resection procedures. We present a case of massive right hydrothorax secondary to a PPF due to recurrent acute pancreatitis. Due to respiratory failure, urgent thoracocentesis was done. Distal pancreatectomy with splenectomy and cholecystectomy was performed. The patient remains well at one-year follow-up.

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A modified technique reduced operative time of laparoendoscopic rendezvous endoscopic retrograde cholangiopancreatography combined with laparoscopic cholecystectomy for concomitant gallstone and common bile ductal stone.

Science.gov (United States)

Liu, Wei; Wang, Qunwei; Xiao, Jing; Zhao, Liying; Huang, Jiangsheng; Tan, Zhaohui; Li, Pengfei

2014-01-01

Laparoendoscopic rendezvous (LERV) endoscopic retrograde cholangiopancreatography (ERCP) and laparoscopic cholecystectomy (LC+ERCP/LERV) are considered an optimal approach for concomitant gallstones and common bile duct stones. The rendezvous technique is essential for the success of procedure. We applied two different LERV techniques, traditional technique and modified technique, in 60 consecutive cases from January 2011 to November 2012. 32 cases who underwent modified technique (group 1) from February 2012 to November 2012 were retrospectively compared to 28 cases (group 2) who underwent traditional technique from January 2011 to January 2012. There was no significant difference between two groups with respect to preoperative demographic features. Although the difference was not statistically significant, the procedure was successfully performed in 31 cases (96.9%) in group 1 and 24 cases (86.2%) in group 2. The mean operative time and time of endoscopic part were 82.6 ± 19.6 min and 26.5 ± 5.99 min in group 1 which were significantly shorter than those in group 2 (118.0 ± 23.1 min and 58.7 ± 13.3 min, resp.). There was no postoperative pancreatitis and mortality in both groups. The mean hospital stay, blood loss, incidence of complications, and residual stone were of no difference in both groups. This study proved that this modified technique can effectively reduce the operative time and time of endoscopic part of LC+ERCP/LERV compared with traditional technique.

Snake resonances

International Nuclear Information System (INIS)

Tepikian, S.

1988-01-01

Siberian Snakes provide a practical means of obtaining polarized proton beams in large accelerators. The effect of snakes can be understood by studying the dynamics of spin precession in an accelerator with snakes and a single spin resonance. This leads to a new class of energy independent spin depolarizing resonances, called snake resonances. In designing a large accelerator with snakes to preserve the spin polarization, there is an added constraint on the choice of the vertical betatron tune due to the snake resonances. 11 refs., 4 figs

1004 RESONANCE November 2013

Indian Academy of Sciences (India)

IAS Admin

1004. RESONANCE │ November 2013. Page 2. 1005. RESONANCE │ November 2013. Page 3. 1006. RESONANCE │ November 2013. Page 4. 1007. RESONANCE │ November 2013. Page 5. 1008. RESONANCE │ November 2013. Page 6. 1009. RESONANCE │ November 2013. Page 7. 1010. RESONANCE ...

Synchrobetatron resonances

International Nuclear Information System (INIS)

1977-03-01

At the 1975 Particle Accelerator Conference it was reported that a class of resonances were observed in SPEAR II that had not appeared before in SPEAR I. While the existence of sideband resonances of the main betatron oscillation frequencies has been previously observed and analyzed, the resonances observed in SPEAR do not appear to be of the same variety. Experiments were performed at SPEAR to identify the mechanism believed to be the most likely explanation. Some of the current experimental knowledge and theoretical views on the source of these resonances are presented

Effects of indomethacin suppositories on serum amylase, inflammatory factors and immune function after endoscopic retrograde cholangiopancreatography

Directory of Open Access Journals (Sweden)

Xiao-Bin Peng

2016-10-01

Full Text Available Objective: To explore the effects of indomethacin suppositories on serum amylase, inflammatory factors and immune function after endoscopic retrograde cholangiopancreatography (ERCP. Methods: A total of 85 patients with common bile duct stones or obstructive jaundice were divided into the observation group (n=45 and the control group (n=40 according to the different treatment methods, both two groups patients were treated with ERCP, patients in the observation group was given indomethacin suppositories 50 mg preoperative 30 min. Serum amylase, inflammatory factors and T cell subsets were detected preoperative, postoperative 6 h and postoperative 24 h. Inflammatory factors including interleukin -10 (IL-10, interleukin -6 (IL-6, tumor necrosis factor alpha (TNF-α and interleukin-4 (IL-4. T cell subsets including CD3+ , CD4+ , CD8+ and calculated CD4+ / CD8+ . Results: In both two groups, postoperative 6 h, 24 h serum amylase were significantly higher than before surgery; in the observation group, the postoperative 6 h, 24 h serum amylase were significantly lower than in the control group at the same time point and the differences were statistically significant (P<0.05. Both two groups’ postoperative 6 h, 24 h serum proinflammatory factor IL-6 and TNF-α increased first and then decreased, both were significantly higher than before surgery; both two groups’ postoperative 6 h, 24 h serum anti-inflammatory factor IL-10 and IL-4 gradually increased, both were significantly higher than before surgery, and the differences were statistically significant (P<0.05; In the observation group, antiinflammatory factor IL-10 and IL-4 significantly increased while pro-inflammatory factor IL-6 and TNF-α significantly decreased compared with the control group at the same time point 6 h and 24 h after surgery, the difference between the two groups was statistically significant (P<0.05. Both two groups’ postoperative 6 h, 24 h T cell subsets CD3+ , CD4+ , CD4

The predictive validity of a situational judgement test, a clinical problem solving test and the core medical training selection methods for performance in specialty training .

Science.gov (United States)

Patterson, Fiona; Lopes, Safiatu; Harding, Stephen; Vaux, Emma; Berkin, Liz; Black, David

2017-02-01

The aim of this study was to follow up a sample of physicians who began core medical training (CMT) in 2009. This paper examines the long-term validity of CMT and GP selection methods in predicting performance in the Membership of Royal College of Physicians (MRCP(UK)) examinations. We performed a longitudinal study, examining the extent to which the GP and CMT selection methods (T1) predict performance in the MRCP(UK) examinations (T2). A total of 2,569 applicants from 2008-09 who completed CMT and GP selection methods were included in the study. Looking at MRCP(UK) part 1, part 2 written and PACES scores, both CMT and GP selection methods show evidence of predictive validity for the outcome variables, and hierarchical regressions show the GP methods add significant value to the CMT selection process. CMT selection methods predict performance in important outcomes and have good evidence of validity; the GP methods may have an additional role alongside the CMT selection methods. © Royal College of Physicians 2017. All rights reserved.

Even order snake resonances

International Nuclear Information System (INIS)

Lee, S.Y.

1993-01-01

We found that the perturbed spin tune due to the imperfection resonance plays an important role in beam depolarization at snake resonances. We also found that even order snake resonances exist in the overlapping intrinsic and imperfection resonances. Due to the perturbed spin tune shift of imperfection resonances, each snake resonance splits into two

Sample-size resonance, ferromagnetic resonance and magneto-permittivity resonance in multiferroic nano-BiFeO3/paraffin composites at room temperature

International Nuclear Information System (INIS)

Wang, Lei; Li, Zhenyu; Jiang, Jia; An, Taiyu; Qin, Hongwei; Hu, Jifan

2017-01-01

In the present work, we demonstrate that ferromagnetic resonance and magneto-permittivity resonance can be observed in appropriate microwave frequencies at room temperature for multiferroic nano-BiFeO 3 /paraffin composite sample with an appropriate sample-thickness (such as 2 mm). Ferromagnetic resonance originates from the room-temperature weak ferromagnetism of nano-BiFeO 3 . The observed magneto-permittivity resonance in multiferroic nano-BiFeO 3 is connected with the dynamic magnetoelectric coupling through Dzyaloshinskii–Moriya (DM) magnetoelectric interaction or the combination of magnetostriction and piezoelectric effects. In addition, we experimentally observed the resonance of negative imaginary permeability for nano BiFeO 3 /paraffin toroidal samples with longer sample thicknesses D=3.7 and 4.9 mm. Such resonance of negative imaginary permeability belongs to sample-size resonance. - Highlights: • Nano-BiFeO 3 /paraffin composite shows a ferromagnetic resonance. • Nano-BiFeO 3 /paraffin composite shows a magneto-permittivity resonance. • Resonance of negative imaginary permeability in BiFeO 3 is a sample-size resonance. • Nano-BiFeO 3 /paraffin composite with large thickness shows a sample-size resonance.

Antibiotic prophylaxis for patients undergoing elective endoscopic ...

African Journals Online (AJOL)

Antibiotic prophylaxis for patients undergoing elective endoscopic retrograde cholangiopancreatography. M Brand, D Bisoz. Abstract. Background. Antibiotic prophylaxis for endoscopic retrograde cholangiopancreatography (ERCP) is controversial. We set out to assess the current antibiotic prescribing practice among ...

Amplitude saturation of MEMS resonators explained by autoparametric resonance

International Nuclear Information System (INIS)

Van der Avoort, C; Bontemps, J J M; Steeneken, P G; Le Phan, K; Van Beek, J T M; Van der Hout, R; Hulshof, J; Fey, R H B

2010-01-01

This paper describes a phenomenon that limits the power handling of MEMS resonators. It is observed that above a certain driving level, the resonance amplitude becomes independent of the driving level. In contrast to previous studies of power handling of MEMS resonators, it is found that this amplitude saturation cannot be explained by nonlinear terms in the spring constant or electrostatic force. Instead we show that the amplitude in our experiments is limited by nonlinear terms in the equation of motion which couple the in-plane length-extensional resonance mode to one or more out-of-plane (OOP) bending modes. We present experimental evidence for the autoparametric excitation of these OOP modes using a vibrometer. The measurements are compared to a model that can be used to predict a power-handling limit for MEMS resonators

Amplitude saturation of MEMS resonators explained by autoparametric resonance

Energy Technology Data Exchange (ETDEWEB)

Van der Avoort, C; Bontemps, J J M; Steeneken, P G; Le Phan, K; Van Beek, J T M [NXP Research, Eindhoven (Netherlands); Van der Hout, R; Hulshof, J [Department of Mathematics, VU University—Faculty of Sciences, De Boelelaan 1081a, 1081 HV Amsterdam (Netherlands); Fey, R H B, E-mail: cas.van.der.avoort@nxp.com [Department of Mechanical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB, Eindhoven (Netherlands)

2010-10-15

This paper describes a phenomenon that limits the power handling of MEMS resonators. It is observed that above a certain driving level, the resonance amplitude becomes independent of the driving level. In contrast to previous studies of power handling of MEMS resonators, it is found that this amplitude saturation cannot be explained by nonlinear terms in the spring constant or electrostatic force. Instead we show that the amplitude in our experiments is limited by nonlinear terms in the equation of motion which couple the in-plane length-extensional resonance mode to one or more out-of-plane (OOP) bending modes. We present experimental evidence for the autoparametric excitation of these OOP modes using a vibrometer. The measurements are compared to a model that can be used to predict a power-handling limit for MEMS resonators.

Outcome of a session of extracorporeal shock wave lithotripsy before endoscopic retrograde cholangiopancreatography for problematic and large common bile duct stones

Science.gov (United States)

Tao, Tao; Zhang, Ming; Zhang, Qi-Jie; Li, Liang; Li, Tao; Zhu, Xiao; Li, Ming-Dong; Li, Gui-Hua; Sun, Shu-Xia

2017-01-01

AIM To compare the efficacy of a session of extracorporeal shock wave lithotripsy (ESWL) before endoscopic retrograde cholangiopancreatography (ERCP) vs ERCP only for problematic and large common bile duct (CBD) stones. METHODS Adult patients with CBD stones for whom initial ERCP was unsuccessful because of the large size of CBD stones were identified. The patients were randomized into two groups, an “ESWL + ERCP group” and an “ERCP-only” group. For ESWL + ERCP cases, ESWL was performed prior to ERCP. Clearance of the CBD, complications related to the ESWL/ERCP procedure, frequency of mechanical lithotripsy use and duration of the ERCP procedure were evaluated in both groups. RESULTS There was no significant difference in baseline characteristics between the two groups. A session of ESWL before ERCP compared with ERCP only resulted in similar outcomes in terms of successful stone removal within the first treatment session (74.2% vs 71.0%, P = 0.135), but a higher clearance rate within the second treatment session (84.4% vs 51.6%, P = 0.018) and total stone clearance (96.0% vs 86.0%, P = 0.029). Moreover, ESWL prior to ERCP not only reduced ERCP procedure time (43 ± 21 min vs 59 ± 28 min, P = 0.034) and the rate of mechanical lithotripsy use (20% vs 30%, P = 0.025), but also raised the clearance rate of extremely large stones (80.0% vs 40.0%, P = 0.016). Post-ERCP complications were similar for the two groups. CONCLUSION Based on the higher rate of successful stone removal and minimal complications, ESWL prior to ERCP appears to be a safe and effective treatment for the endoscopic removal of problematic and large CBD stones. PMID:28785149

Simultaneous electrical and mechanical resonance drive for large signal amplification of micro resonators

KAUST Repository

Hasan, M. H.

2018-01-12

Achieving large signal-noise ratio using low levels of excitation signal is key requirement for practical applications of micro and nano electromechanical resonators. In this work, we introduce the double electromechanical resonance drive concept to achieve an order-of-magnitude dynamic signal amplification in micro resonators. The concept relies on simultaneously activating the micro-resonator mechanical and electrical resonance frequencies. We report an input voltage amplification up to 15 times for a micro-resonator when its electrical resonance is tuned to match the mechanical resonance that leads to dynamic signal amplification in air (Quality factor enhancement). Furthermore, using a multi-frequency excitation technique, input voltage and vibrational amplification of up to 30 times were shown for the same micro-resonator while relaxing the need to match its mechanical and electrical resonances.

Simultaneous electrical and mechanical resonance drive for large signal amplification of micro resonators

KAUST Repository

Hasan, M. H.; Alsaleem, F. M.; Jaber, Nizar; Hafiz, Md Abdullah Al; Younis, Mohammad I.

2018-01-01

Achieving large signal-noise ratio using low levels of excitation signal is key requirement for practical applications of micro and nano electromechanical resonators. In this work, we introduce the double electromechanical resonance drive concept to achieve an order-of-magnitude dynamic signal amplification in micro resonators. The concept relies on simultaneously activating the micro-resonator mechanical and electrical resonance frequencies. We report an input voltage amplification up to 15 times for a micro-resonator when its electrical resonance is tuned to match the mechanical resonance that leads to dynamic signal amplification in air (Quality factor enhancement). Furthermore, using a multi-frequency excitation technique, input voltage and vibrational amplification of up to 30 times were shown for the same micro-resonator while relaxing the need to match its mechanical and electrical resonances.

Erbium-doped fiber ring resonator for resonant fiber optical gyro applications

Science.gov (United States)

Li, Chunming; Zhao, Rui; Tang, Jun; Xia, Meijing; Guo, Huiting; Xie, Chengfeng; Wang, Lei; Liu, Jun

2018-04-01

This paper reports a fiber ring resonator with erbium-doped fiber (EDF) for resonant fiber optical gyro (RFOG). To analyze compensation mechanism of the EDF on resonator, a mathematical model of the erbium-doped fiber ring resonator (EDFRR) is established based on Jones matrix to be followed by the design and fabrication of a tunable EDFRR. The performances of the fabricated EDFRR were measured and the experimental Q-factor of 2 . 47 × 108 and resonant depth of 109% were acquired separately. Compared with the resonator without the EDF, the resonant depth and Q-factor of the proposed device are increased by 2.5 times and 14 times, respectively. A potential optimum shot noise limited resolution of 0 . 042∘ / h can be obtained for the RFOG, which is promising for low-cost and high precise detection.

Quantum mechanical resonances

International Nuclear Information System (INIS)

Cisneros S, A.; McIntosh, H.V.

1982-01-01

A discussion of the nature of quantum mechanical resonances is presented from the point of view of the spectral theory of operators. In the case of Bohr-Feshbach resonances, graphs are presented to illustrate the theory showing the decay of a doubly excited metastable state and the excitation of the resonance by an incident particle with proper energy. A characterization of resonances is given as well as a procedure to determine widths using the spectral density function. A sufficient condition is given for the validity of the Breit-Wigner formula for Bohr-Feshbach resonances. (author)

3C-SiC microdisk mechanical resonators with multimode resonances at radio frequencies

Science.gov (United States)

Lee, Jaesung; Zamani, Hamidrera; Rajgopal, Srihari; Zorman, Christian A.; X-L Feng, Philip

2017-07-01

We report on the design, modeling, fabrication and measurement of single-crystal 3C-silicon carbide (SiC) microdisk mechanical resonators with multimode resonances operating at radio frequencies (RF). These microdisk resonators (center-clamped on a vertical stem pedestal) offer multiple flexural-mode resonances with frequencies dependent on both disk and anchor dimensions. The resonators are made using a novel fabrication method comprised of focused ion beam nanomachining and hydroflouic : nitric : acetic (HNA) acid etching. Resonance peaks (in the frequency spectrum) are detected through laser-interferometry measurements. Resonators with different dimensions are tested, and multimode resonances, mode splitting, energy dissipation (in the form of quality factor measurement) are investigated. Further, we demonstrate a feedback oscillator based on a passive 3C-SiC resonator. This investigation provides important guidelines for microdisk resonator development, ranging from an analytical prediction of frequency scaling law to fabrication, suggesting RF microdisk resonators can be good candidates for future sensing applications in harsh environments.

Consensus for the management of IPMN

International Nuclear Information System (INIS)

Tanaka, Masao

2012-01-01

International Consensus Guidelines for management of intraductal papillary mucious neoplasms (IPMIN) and mucious cystic neoplasms (MCN) of the pancreas defined their difference in 2006 Sendai Conference, and this paper describes about their still remaining problem in the consensus by referring related literatures. The author explains the macroscopic classification of IPMIN in types of brunch duct (BD), main duct (MD) and their mixture. Guidelines are obscure concerning which of the histology or preoperative imaging is appropriate for diagnosis of the mixed type and the author considers that the latter imaging is better as the method used has influence on indication of surgery thereafter. MD-IPMIN is easily diagnosed differentially from chronic pantreatitis, but differential diagnosis of BD-IPMIN and other cystic lesion is rather complex, particularly, for MCN tending to malignancy and macrocystic serous CN (SCN). For this, analysis of the intraductal mucious liquid obtained by endoscopic ultrasonography-fine needle aspiration biopsy (EUS-FNA) is useful but its safety to see the grade of malignancy for extending the indication leading to resection is not established. Diagnosis of the malignancy of BD-IPMIN can be done best based on the presence of mural nodules, and other markers are of low reliability. In fact, cysts with >3 cm, when resected, are found mostly (80%) benign, indicating the necessity of a more reliable sign and of detailed classification of sub-tissue type. The purpose of progress observation involves diagnoses of changing to malignancy, of concurrent cancer and of recurrence of resected lesion, and an author's case report of this is given with MR cholangiopancreatography (MRCP), CT and MRI images. Observatory approach, interval and period of the disease progression are yet unestablished. (T.T.)

Nonlinear resonances

CERN Document Server

Rajasekar, Shanmuganathan

2016-01-01

This introductory text presents the basic aspects and most important features of various types of resonances and anti-resonances in dynamical systems. In particular, for each resonance, it covers the theoretical concepts, illustrates them with case studies, and reviews the available information on mechanisms, characterization, numerical simulations, experimental realizations, possible quantum analogues, applications and significant advances made over the years. Resonances are one of the most fundamental phenomena exhibited by nonlinear systems and refer to specific realizations of maximum response of a system due to the ability of that system to store and transfer energy received from an external forcing source. Resonances are of particular importance in physical, engineering and biological systems - they can prove to be advantageous in many applications, while leading to instability and even disasters in others. The book is self-contained, providing the details of mathematical derivations and techniques invo...

Surgical management of bile duct injuries following open or laparoscopic cholecystectomy

International Nuclear Information System (INIS)

Hadi, A.; Aman, Z.; Khan, S.A.

2013-01-01

Objective: To evaluate the management of bile duct injuries following open and laparoscopic cholecystectomy in a tertiary care hospital. Methods: The descriptive case series was conducted from July 2002 to June 2008 at Hayatabad Medical Complex Peshawar, Pakistan. A total of 32 patients who sustained extra hepatic bile duct injuries during open and laparoscopic cholecystectomy were included. Patients having hepatobiliary malignancy or those managed through endoscopic retrograde cholangiopancreatography and stenting were excluded. Patients were thoroughly investigated including to reach a final diagnosis, and were followed up for 02 years. Results: The mean age of patients was 45.4+9-2.7 years with a female preponderance (M:F=1:9.7). The time of presentation was up to 03 months after initial surgery. Seven (21.87%) patients sustained bile duct injury during laparoscopic cholecystectomy, while 25 (78.13%) sustained injury during open procedure. Abdominal ultrasound scan was performed in 29 (90.63%) cases, endoscopic retrograde cholangiopancreatography in 14 (43.75%) and magnetic resonance cholangiopancreatography in 26 (81.25%) cases. Eleven (34.37%) patients had common bile duct leak, 9 (28.13%) had common hepatic duct injury, 9 (28.13%) had CBD strictures and 3 (09.37%) had injury to the biliary tree at porta hepatis level. Operative procedures performed included Roux-en-Y hepaticojejunostomy in 19 (59.38%) cases, choledochoduodenostomy in 7 (21.88%) cases, Roux-en-Y portoentrostomy and primary repair in 3 (09.37%) cases each. Postoperative morbidity included recurrent cholangitis 9 (28.12%), wound infection 4 (12.50%) and bile leakage 2 (06.25%). Hospital stay ranged 08-16 days. Hospital mortality rate was 03.13%, (n=1). Conclusion: The most frequent site of bile duct injury during open and laparoscopic cholecystectomy was the common bile duct, and Roux-en-Y hepaticojejunostomy was the procedure of choice by experienced surgeons for the management of such injuries

Regenerative feedback resonant circuit

Science.gov (United States)

Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

2014-09-02

A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

Sample-size resonance, ferromagnetic resonance and magneto-permittivity resonance in multiferroic nano-BiFeO{sub 3}/paraffin composites at room temperature

Energy Technology Data Exchange (ETDEWEB)

Wang, Lei; Li, Zhenyu; Jiang, Jia; An, Taiyu; Qin, Hongwei; Hu, Jifan, E-mail: hujf@sdu.edu.cn

2017-01-01

In the present work, we demonstrate that ferromagnetic resonance and magneto-permittivity resonance can be observed in appropriate microwave frequencies at room temperature for multiferroic nano-BiFeO{sub 3}/paraffin composite sample with an appropriate sample-thickness (such as 2 mm). Ferromagnetic resonance originates from the room-temperature weak ferromagnetism of nano-BiFeO{sub 3}. The observed magneto-permittivity resonance in multiferroic nano-BiFeO{sub 3} is connected with the dynamic magnetoelectric coupling through Dzyaloshinskii–Moriya (DM) magnetoelectric interaction or the combination of magnetostriction and piezoelectric effects. In addition, we experimentally observed the resonance of negative imaginary permeability for nano BiFeO{sub 3}/paraffin toroidal samples with longer sample thicknesses D=3.7 and 4.9 mm. Such resonance of negative imaginary permeability belongs to sample-size resonance. - Highlights: • Nano-BiFeO{sub 3}/paraffin composite shows a ferromagnetic resonance. • Nano-BiFeO{sub 3}/paraffin composite shows a magneto-permittivity resonance. • Resonance of negative imaginary permeability in BiFeO{sub 3} is a sample-size resonance. • Nano-BiFeO{sub 3}/paraffin composite with large thickness shows a sample-size resonance.

Depolarization due to the resonance tail during a fast resonance jump

International Nuclear Information System (INIS)

Ruth, R.D.

1980-01-01

The mechanism of depolarization due to a fast resonance jump is studied. The dominant effect for cases of interest is not dependent on the rate of passage through resonance, but rather on the size of the resonance jump as compared to the width, epsilon, of the resonance. The results are applied to a calculation of depolarization in the AGS at Brookhaven National Laboratory

Management of ampullary tumours in children: still a challenge.

Science.gov (United States)

Fernandez-Eire, P; Vazquez Castelo, J L; Herreros Villaraviz, M; Fernandez Caamaño, B; Gonzalez-Carreró, J; Ausania, F

2017-05-01

This study describes the case of the youngest patient ever reported with ampullary adenoma. The incidence of ampullary adenomas in childhood is unknown. Endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound are used in adults to assess and treat these lesions, although there are no instruments designed specifically for use in young children. A six-year-old girl was admitted for abdominal pain, vomiting, pruritus and weight loss. Abdominal ultrasound showed biliary tree (8mm) and pancreatic duct dilatation (4mm). Magnetic resonance cholangiopancreatography and computed tomography confirmed these findings, and also showed displacement of the ampulla to the left upper quadrant. An upper endoscopy confirmed a large ampullary adenoma. A laparotomy was performed and a 5cm villous tumour arising from the ampulla was excised. The postoperative course was uneventful. The histology demonstrated adenoma of the ampulla (intestinal type) without low-grade dysplasia. all clinical and radiological parameters are normal at 20 months follow-up. We describe the case of the youngest patient ever reported with ampullary adenoma. Pancreaticoduodenectomy carries high morbidity and mortality rates, and therefore it should be avoided in absence of histologically proven malignancy. We believe that surgical ampullectomy is a safe and oncologically correct procedure until better endoscopic instruments for peadiatric use will be designed.

Narrow dibaryon resonances

International Nuclear Information System (INIS)

Kajdalov, A.B.

1986-01-01

Experimental data on np interactions indicating to existence of narrow resonances in pp-system are discussed. Possible theoretical interpretations of these resonances are given. Experimental characteristics of the dibaryon resonances with isospin I=2 are considered

A Modified Technique Reduced Operative Time of Laparoendoscopic Rendezvous Endoscopic Retrograde Cholangiopancreatography Combined with Laparoscopic Cholecystectomy for Concomitant Gallstone and Common Bile Ductal Stone

Directory of Open Access Journals (Sweden)

Wei Liu

2014-01-01

Full Text Available Laparoendoscopic rendezvous (LERV endoscopic retrograde cholangiopancreatography (ERCP and laparoscopic cholecystectomy (LC+ERCP/LERV are considered an optimal approach for concomitant gallstones and common bile duct stones. The rendezvous technique is essential for the success of procedure. We applied two different LERV techniques, traditional technique and modified technique, in 60 consecutive cases from January 2011 to November 2012. 32 cases who underwent modified technique (group 1 from February 2012 to November 2012 were retrospectively compared to 28 cases (group 2 who underwent traditional technique from January 2011 to January 2012. There was no significant difference between two groups with respect to preoperative demographic features. Although the difference was not statistically significant, the procedure was successfully performed in 31 cases (96.9% in group 1 and 24 cases (86.2% in group 2. The mean operative time and time of endoscopic part were 82.6 ± 19.6 min and 26.5 ± 5.99 min in group 1 which were significantly shorter than those in group 2 (118.0 ± 23.1 min and 58.7 ± 13.3 min, resp.. There was no postoperative pancreatitis and mortality in both groups. The mean hospital stay, blood loss, incidence of complications, and residual stone were of no difference in both groups. This study proved that this modified technique can effectively reduce the operative time and time of endoscopic part of LC+ERCP/LERV compared with traditional technique.

Applied neutron resonance theory

International Nuclear Information System (INIS)

Froehner, F.H.

1980-01-01

Utilisation of resonance theory in basic and applications-oriented neutron cross section work is reviewed. The technically important resonance formalisms, principal concepts and methods as well as representative computer programs for resonance parameter extraction from measured data, evaluation of resonance data, calculation of Doppler-broadened cross sections and estimation of level-statistical quantities from resonance parameters are described. (author)

Applied neutron resonance theory

International Nuclear Information System (INIS)

Froehner, F.H.

1978-07-01

Utilisation of resonance theory in basic and applications-oriented neutron cross section work is reviewed. The technically important resonance formalisms, principal concepts and methods as well as representative computer programs for resonance parameter extraction from measured data, evaluation of resonance data, calculation of Doppler-broadened cross sections and estimation of level-statistical quantities from resonance parameters are described. (orig.) [de

Total Pancreatic Fracture Due to Blunt Trauma: Report of a Rare Case

Directory of Open Access Journals (Sweden)

Kamil Gulpinar

2016-05-01

Full Text Available A rare case of pancreatic fracture due to blunt trauma was presented. The patient was 70 year old male who had a motor vehicle collision and was suspected a pancreatic trauma due his examinations with ultrasound and computerized tomography. The diagnosis of splenic injury and pancreas body total fracture in the point where the portal vein crosses the pancreatic body was made with the help of magnetic resonance cholangiopancreatography. He was taken to emergency surgery where a splenectomy and a distal pancreatectomy were performed. We represented this infrequent case of pancreatic fracture and its complications after blunt abdominal trauma and discuss the diagnostic and management practices.

Rare bile duct anomaly: B3 duct draining to gallbladder

Directory of Open Access Journals (Sweden)

Seung Eun Lee

2016-01-01

Full Text Available A 10-year-old girl presented with recurrent right upper abdominal pain and dyspepsia. Magnetic resonance cholangiopancreatography revealed a dilated common channel of intrahepatic bile duct of segment 3 (B3 and segment 4 (B4 drained into the gallbladder directly. The patient underwent laparoscopic cholecystectomy and Roux-en Y hepaticojejunostomy (B3-jejunostomy. Among the anatomical variability of the biliary system, the cholecystohepatic ducts are controversial in existence and incidence. We report a very rare variant of a cholecystohepatic duct in which the B3 duct drained into gallbladder directly and to the best of our knowledge this is the first report.

Resonant snubber inverter

Science.gov (United States)

Lai, Jih-Sheng; Young, Sr., Robert W.; Chen, Daoshen; Scudiere, Matthew B.; Ott, Jr., George W.; White, Clifford P.; McKeever, John W.

1997-01-01

A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

Resonance

DEFF Research Database (Denmark)

Petersen, Nils Holger

2014-01-01

A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice.......A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice....

Multiple photon resonances

International Nuclear Information System (INIS)

Elliott, C.J.; Feldman, B.J.

1979-02-01

A detailed theoretical analysis is presented of the interaction of intense near-resonant monochromatic radiation with an N-level anharmonic oscillator. In particular, the phenomenon of multiple photon resonance, the process by which an N-level system resonantly absorbs two or more photons simultaneously, is investigated. Starting from the Schroedinger equation, diagrammatic techniques are developed that allow the resonant process to be analyzed quantitatively, in analogy with well-known two-level coherent phenomena. In addition, multiple photon Stark shifts of the resonances, shifts absent in two-level theory, are obtained from the diagrams. Insights into the nature of multiple photon resonances are gained by comparing the quantum mechanical system with classical coupled pendulums whose equations of motion possess identical eigenvalues and eigenvectors. In certain limiting cases, including that of the resonantly excited N-level harmonic oscillator and that of the equally spaced N-level system with equal matrix elements, analytic results are derived. The influence of population relaxation and phase-disrupting collisions on the multiple photon process are also analyzed, the latter by extension of the diagrammatic technique to the density matrix equations of motion. 11 figures

Lateral acoustic wave resonator comprising a suspended membrane of low damping resonator material

Science.gov (United States)

Olsson, Roy H.; El-Kady; , Ihab F.; Ziaei-Moayyed, Maryam; Branch; , Darren W.; Su; Mehmet F.,; Reinke; Charles M.,

2013-09-03

A very high-Q, low insertion loss resonator can be achieved by storing many overtone cycles of a lateral acoustic wave (i.e., Lamb wave) in a lithographically defined suspended membrane comprising a low damping resonator material, such as silicon carbide. The high-Q resonator can sets up a Fabry-Perot cavity in a low-damping resonator material using high-reflectivity acoustic end mirrors, which can comprise phononic crystals. The lateral overtone acoustic wave resonator can be electrically transduced by piezoelectric couplers. The resonator Q can be increased without increasing the impedance or insertion loss by storing many cycles or wavelengths in the high-Q resonator material, with much lower damping than the piezoelectric transducer material.

Resonator quantum electrodynamics on a microtrap chip; Resonator-Quantenelektrodynamik auf einem Mikrofallenchip

Energy Technology Data Exchange (ETDEWEB)

Steinmetz, Tilo

2008-04-29

In the present dissertation experiments on resonator quantum electrodynamics on a microtrap chip are described. Thereby for the first time single atoms catched in a chip trap could be detected. For this in the framework of this thesis a novel optical microresonator was developed, which can because of its miniaturization be combined with the microtrap technique introduced in our working group for the manipulation of ultracold atoms. For this resonator glass-fiber ends are used as mirror substrates, between which a standing light wave is formed. With such a fiber Fabry-Perot resonator we obtain a finess of up to {approx}37,000. Because of the small mode volumina in spite of moderate resonator quality the coherent interaction between an atom and a photon can be made so large that the regime of the strong atom-resonator coupling is reached. For the one-atom-one-photon coupling rate and the one-atom-one-photon cooperativity thereby record values of g{sub 0}=2{pi}.300 MHz respectively C{sub 0}=210 are reached. Just so for the first time the strong coupling regime between a Bose-Einstein condensate (BEC) and the field of a high-quality resonator could be reached. The BEC was thereby by means of the magnetic microtrap potentials deterministically brought to a position within the resonator and totally transformed in a well defined antinode of an additionally optical standing-wave trap. The spectrum of the coupled atom-resonator system was measured for different atomic numbers and atom-resonator detunings, whereby a collective vacuum Rabi splitting of more than 20 GHz could be reached. [German] In der vorliegenden Dissertation werden Experimente zur Resonator-Quantenelektrodynamik auf einem Mikrofallenchip beschrieben. Dabei konnte u. a. erstmals einzelne, in einer Chipfalle gefangene Atome detektiert werden. Hier fuer wurde im Rahmen dieser Arbeit ein neuartiger optischer Mikroresonator entwickelt, der sich dank seiner Miniaturisierung mit der in unserer Arbeitsgruppe

Cholangiographic Features in Opium-Addicted Patients at a Tertiary Hospital in Iran

Directory of Open Access Journals (Sweden)

Amir Houshang Mohammad Alizadeh

2012-01-01

Full Text Available Background/Aims. Destructive and metabolic changes in hepatobiliary system have been demonstrated following opium use; however, cholangiographic features of bile ducts in opium-addicted patients with sphincter of Oddi dysfunction are not clearly determined. We described these differences and assessed the effects of opium use on postendoscopic retrograde cholangiopancreatography complications. Methodology. One hundred and nineteen patients with the diagnosis of sphinctre of Oddi dysfunction according to the Geenen-Hogan classification were studied. Eight patients were confirmed opium-addicted and others were nonaddicted. Change of serum amylase concentrations after endoscopic retrograde cholangiopancreatography and clinical diagnosis of addicted and non-addicted patients were compared. Results. Serum concentrations of liver aminotransferases and alkaline phosphatase were similar between the two groups. Serum concentration of amylase before endoscopic retrograde cholangiopancreatography was similar between them, whereas concentration of this enzyme was higher in nonaddicted ones after endoscopic retrograde cholangiopancreatography. Regarding pathologic changes in papilla, opium addiction group in comparison with control group statistically showed more tumoral features (25.0% versus 5.4% and ulcerated changes (12.5% versus 0.0%. Conclusions. Opium use can increase probability of papilla ulcerative and tumoral changes in patients with sphinctre of Oddi dysfunction. Postendoscopic retrograde cholangiopancreatography serum amylase level may be reduced following opium addiction.

Electron paramagnetic resonance

CERN Document Server

Al'tshuler, S A

2013-01-01

Electron Paramagnetic Resonance is a comprehensive text on the field of electron paramagnetic resonance, covering both the theoretical background and the results of experiment. This book is composed of eight chapters that cover theoretical materials and experimental data on ionic crystals, since these are the materials that have been most extensively studied by the methods of paramagnetic resonance. The opening chapters provide an introduction to the basic principles of electron paramagnetic resonance and the methods of its measurement. The next chapters are devoted to the theory of spectra an

Influence of resonance parameters' correlations on the resonance integral uncertainty; 55Mn case

International Nuclear Information System (INIS)

Zerovnik, Gasper; Trkov, Andrej; Capote, Roberto; Rochman, Dimitri

2011-01-01

For nuclides with a large number of resonances the covariance matrix of resonance parameters can become very large and expensive to process in terms of the computation time. By converting covariance matrix of resonance parameters into covariance matrices of background cross-section in a more or less coarse group structure a considerable amount of computer time and memory can be saved. The question is how important is the information that is discarded in the process. First, the uncertainty of the 55 Mn resonance integral was estimated in narrow resonance approximation for different levels of self-shielding using Bondarenko method by random sampling of resonance parameters according to their covariance matrices from two different 55 Mn evaluations: one from Nuclear Research and Consultancy Group NRG (with large uncertainties but no correlations between resonances), the other from Oak Ridge National Laboratory (with smaller uncertainties but full covariance matrix). We have found out that if all (or at least significant part of the) resonance parameters are correlated, the resonance integral uncertainty greatly depends on the level of self-shielding. Second, it was shown that the commonly used 640-group SAND-II representation cannot describe the increase of the resonance integral uncertainty. A much finer energy mesh for the background covariance matrix would have to be used to take the resonance structure into account explicitly, but then the objective of a more compact data representation is lost.

Quasi-resonant converter with divided resonant capacitor on primary and secondary side

OpenAIRE

Shiroyama, Hironobu; Matsuo, Hirofumi; Ishizuka, Yoichi

2009-01-01

This paper presents a quasi-resonant converter with divided resonant capacitor on primary and secondary side of the isolation transformer. A conventional quasi-resonant converter using flyback topology can realize soft switching with simple circuit. However, relatively large surge voltage is generated in the switching device. To suppress such surge voltage, resonant capacitor is divided on primary side and secondary side in the proposed converter. In case of prototype 95W converter, the volta...

Diseases of the hepatobiliary system as a cause of acute abdomen; Erkrankungen des hepatobiliaeren Systems als Ursache des akuten Abdomens

Energy Technology Data Exchange (ETDEWEB)

Schima, W.; Eisenhuber-Stadler, E. [Krankenhaus Goettlicher Heiland, Abteilung fuer Radiologie und bildgebende Diagnostik, Wien (Austria); Koelblinger, C.; Kulinna-Cosentini, C.; Ba-Ssalamah, A. [Medizinische Universitaet Wien, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

2010-03-15

Diseases of the liver and biliary system are common causes of acute abdominal pain and gallstone disease predisposes to cholecystitis and cholangiolithiasis. Sonography is the method of choice for the assessment of cholecystitis, whereas magnetic resonance cholangiopancreaticography (MRCP) is the standard technique to detect stones in the common bile duct. Multi-detector computed tomography (MDCT) is ideal for detection of associated complications, including abscess formation and gall stone ileus. Pyogenic, amebic and fungal liver abscesses are reliably diagnosed with MDCT which can also be used for interventional radiologic therapy of liver abscesses by percutaneous aspiration or drainage procedures. The second most common cause of liver rupture after blunt trauma is spontaneous rupture of hypervascular liver tumors (i.e., HCC, adenoma, angiosarcoma) and due to medical procedures. Multi-phase contrast-enhanced MDCT can reliably detect active bleeding to guide further therapy in these cases. (orig.) [German] Die Cholezystitis ist eine der haeufigsten Ursachen fuer ein akutes Abdomen. Waehrend die Sonographie die Methode der Wahl zum Nachweis einer Cholezystolithiasis und Cholezystitis ist, steht bei der Entwicklung von Komplikationen die Multidetektorcomputertomographie (MDCT) diagnostisch im Vordergrund. Die Magnetresonanzcholangiopankreatikographie (MRCP) hat einen hohen Stellenwert bei der Abklaerung der Cholangiolithiasis, v. a. bei der Differenzialdiagnose zu anderen Ursachen einer Cholestase. Die Diagnose bakterieller, Amoeben- oder fungaler Leberabszesse kann mittels Sonographie oder MDCT rasch gestellt werden, wobei diese Methoden auch fuer die interventionelle radiologische Therapie von Leberabszessen (Punktion oder Drainage) gut geeignet sind. Die mehrphasige, kontrastmittelverstaerkte MDCT ist die Methode der Wahl fuer den Nachweis von Leberinfarkten oder -rupturen, da bei diesen Erkrankungen bzw. Verletzungsfolgen die Darstellung der

Advances in magnetic resonance 10

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 10, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters that examine superoperators in magnetic resonance; ultrasonically modulated paramagnetic resonance; and the utility of electron paramagnetic resonance (EPR) and electron-nuclear double-resonance (ENDOR) techniques for studying low-frequency modes of atomic fluctuations and their significance for understanding the mechanism of structural phase transitions in solids.

One-loop renormalization of Resonance Chiral Theory: scalar and pseudoscalar resonances

International Nuclear Information System (INIS)

Rosell, Ignasi; Ruiz-FemenIa, Pedro; Portoles, Jorge

2005-01-01

We consider the Resonance Chiral Theory with one multiplet of scalar and pseudoscalar resonances, up to bilinear couplings in the resonance fields, and evaluate its β-function at one-loop with the use of the background field method. Thus we also provide the full set of operators that renormalize the theory at one loop and render it finite

Slotted cage resonator for high-field magnetic resonance imaging of rodents

Energy Technology Data Exchange (ETDEWEB)

Marrufo, O; Vasquez, F; Solis, S E; Rodriguez, A O, E-mail: arog@xanum.uam.mx [Departamento de Ingenieria Electrica, Universidad Autonoma Metropolitana Iztapalapa, Mexico, DF 09340 (Mexico)

2011-04-20

A variation of the high-frequency cavity resonator coil was experimentally developed according to the theoretical frame proposed by Mansfield in 1990. Circular slots were used instead of cavities to form the coil endplates and it was called the slotted cage resonator coil. The theoretical principles were validated via a coil equivalent circuit and also experimentally with a coil prototype. The radio frequency magnetic field, B1, produced by several coil configurations was numerically simulated using the finite-element approach to investigate their performances. A transceiver coil, 8 cm long and 7.6 cm in diameter, and composed of 4 circular slots with a 15 mm diameter on both endplates, was built to operate at 300 MHz and quadrature driven. Experimental results obtained with the slotted cage resonator coil were presented and showed very good agreement with the theoretical expectations for the resonant frequency as a function of the coil dimensions and slots. A standard birdcage coil was also built for performance comparison purposes. Phantom images were then acquired to compute the signal-to-noise ratio of both coils showing an important improvement of the slotted cage coil over the birdcage coil. The whole-body images of the mouse were also obtained showing high-quality images. Volume resonator coils can be reliably built following the physical principles of the cavity resonator design for high-field magnetic resonance imaging applications of rodents.

Collaborative resonant writing and musical improvisation to explore the concept of resonance

DEFF Research Database (Denmark)

Lindvang, Charlotte; Pedersen, Inge Nygaard; Jacobsen, Stine Lindahl

2018-01-01

phenomenon consisting of physical vibrations and acoustic sounding that offers a clear logic, and (2) a metaphorical conceptualization used to describe and understand complex psychological processes of human relationships. The process of collaborative writing led to the discovery or development of a ninestep......Resonance is often used to characterize relationships, but it is a complex concept that explains quite different physical, physiological and psychological processes. With the aim of gaining deeper insight into the concept of resonance, a group of ten music therapy researchers, all colleagues...... procedure including different collaborative resonant writing procedures and musical improvisation, as well as of a series of metaphors to explain therapeutic interaction, resonant learning and ways of resonant exploration....

Injection-controlled laser resonator

Science.gov (United States)

Chang, J.J.

1995-07-18

A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality. 5 figs.

MRI (Magnetic Resonance Imaging)

Science.gov (United States)

... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Magnetic Resonance Imaging (MRI) is a medical imaging procedure for ...

Experimental Investigation of 2:1 and 3:1 Internal Resonances in Nonlinear MEMS Arch Resonators

KAUST Repository

Ramini, Abdallah; Hajjaj, Amal Z.; Younis, Mohammad I.

2016-01-01

We demonstrate experimentally internal resonances in MEMS resonators. The investigation is conducted on in-plane MEMS arch resonators fabricated with a highly doped silicon. The resonators are actuated electrostatically and their stiffness are tuned by electrothermal loading by passing an electrical current though the microstructures. We show that through this tuning, the ratio of the various resonance frequencies can be varied and set at certain ratios. Particularly, we adjust the resonance frequencies of two different vibrational modes to 2:1 and 3:1. Finally, we validate the internal resonances at these ratios through frequency-response curves and FFTs.

Experimental Investigation of 2:1 and 3:1 Internal Resonances in Nonlinear MEMS Arch Resonators

KAUST Repository

Ramini, Abdallah

2016-12-05

We demonstrate experimentally internal resonances in MEMS resonators. The investigation is conducted on in-plane MEMS arch resonators fabricated with a highly doped silicon. The resonators are actuated electrostatically and their stiffness are tuned by electrothermal loading by passing an electrical current though the microstructures. We show that through this tuning, the ratio of the various resonance frequencies can be varied and set at certain ratios. Particularly, we adjust the resonance frequencies of two different vibrational modes to 2:1 and 3:1. Finally, we validate the internal resonances at these ratios through frequency-response curves and FFTs.

Resonant ultrasound spectrometer

Science.gov (United States)

Migliori, Albert; Visscher, William M.; Fisk, Zachary

1990-01-01

An ultrasound resonant spectrometer determines the resonant frequency spectrum of a rectangular parallelepiped sample of a high dissipation material over an expected resonant response frequency range. A sample holder structure grips corners of the sample between piezoelectric drive and receive transducers. Each transducer is mounted on a membrane for only weakly coupling the transducer to the holder structure and operatively contacts a material effective to remove system resonant responses at the transducer from the expected response range. i.e., either a material such as diamond to move the response frequencies above the range or a damping powder to preclude response within the range. A square-law detector amplifier receives the response signal and retransmits the signal on an isolated shield of connecting cabling to remove cabling capacitive effects. The amplifier also provides a substantially frequency independently voltage divider with the receive transducer. The spectrometer is extremely sensitive to enable low amplitude resonance to be detected for use in calculating the elastic constants of the high dissipation sample.

Magnetic resonance of phase transitions

CERN Document Server

Owens, Frank J; Farach, Horacio A

1979-01-01

Magnetic Resonance of Phase Transitions shows how the effects of phase transitions are manifested in the magnetic resonance data. The book discusses the basic concepts of structural phase and magnetic resonance; various types of magnetic resonances and their underlying principles; and the radiofrequency methods of nuclear magnetic resonance. The text also describes quadrupole methods; the microwave technique of electron spin resonance; and the Mössbauer effect. Phase transitions in various systems such as fluids, liquid crystals, and crystals, including paramagnets and ferroelectrics, are also

Pneumoperitoneum after Endoscopic Retrograde Cholangiopancreatography due to Rupture of Intrahepatic Bile Ducts and Glisson’s Capsule in Hepatic Metastasis: A Case Report and Review of Literature

Directory of Open Access Journals (Sweden)

Zubair Khan

2017-10-01

Full Text Available Introduction: Endoscopic retrograde cholangiopancreatography (ERCP has been proven to be a safe and effective method for diagnosis and treatment of biliary and pancreatic disorders. Major complications of ERCP include pancreatitis, hemorrhage, cholangitis, and duodenal perforation. We report a third case in literature of pneumoperitoneum after ERCP due to rupture of intrahepatic bile ducts and Glisson’s capsule in a peripheral hepatic lesion. Case Report: A 50-year-old male with a history of metastatic pancreatic neuroendocrine tumor and who had a partially covered metallic stent placed in the biliary tree 1 year ago presented to the oncology clinic with fatigue, abdominal pain, and hypotension. He was planned for ERCP for possible cholangitis secondary to obstructed previously placed biliary stent. However, the duodenoscope could not be advanced to the level of the major papilla because of narrowed pylorus and severely strictured duodenal sweep. Forward-view gastroscope was then passed with careful manipulation to the severely narrowed second part of the duodenum where the previously placed metallic stent was visualized. Balloon sweeping of stenting was done. Cholangiography did not show any leak. Following the procedure, the patient underwent CT scan of the abdomen that showed pneumoperitoneum which was communicating with pneumobilia through a loculated air collection in necrotic hepatic metastasis perforating Glisson’s capsule. The patient was managed conservatively. Conclusion: In our case, pneumoperitoneum resulted from rupture of intrahepatic bile ducts and Glisson’s capsule in hepatic metastasis. This case emphasizes the need for close clinical and radiological observation of patients with hepatic masses (primary or metastatic subjected to ERCP.

Resonance Raman Optical Activity and Surface Enhanced Resonance Raman Optical Activity analysis of Cytochrome C

DEFF Research Database (Denmark)

Johannessen, Christian; Abdali, Salim; White, Peter C.

2007-01-01

High quality Resonance Raman (RR) and resonance Raman Optical Activity (ROA) spectra of cytochrome c were obtained in order to perform full assignment of spectral features of the resonance ROA spectrum. The resonance ROA spectrum of cytochrome c revealed a distinct spectral signature pattern due...... to resonance enhanced skeletal porphyrin vibrations, more pronounced than any contribution from the protein back-bone. Combining the intrinsic resonance enhancement of cytochrome c with surface plasmon enhancement by colloidal silver particles, the Surface Enhanced Resonance Raman Scattering (SERRS) and Chiral...... Enhanced Raman Spectroscopy (ChERS) spectra of the protein were successfully obtained at very low concentration (as low as 1 µM). The assignment of spectral features was based on the information obtained from the RR and resonance ROA spectra. Excellent agreement between RR and SERRS spectra is reported...

Mode Coupling and Nonlinear Resonances of MEMS Arch Resonators for Bandpass Filters

KAUST Repository

Hajjaj, Amal Z.

2017-01-30

We experimentally demonstrate an exploitation of the nonlinear softening, hardening, and veering phenomena (near crossing), where the frequencies of two vibration modes get close to each other, to realize a bandpass filter of sharp roll off from the passband to the stopband. The concept is demonstrated based on an electrothermally tuned and electrostatically driven MEMS arch resonator operated in air. The in-plane resonator is fabricated from a silicon-on-insulator wafer with a deliberate curvature to form an arch shape. A DC current is applied through the resonator to induce heat and modulate its stiffness, and hence its resonance frequencies. We show that the first resonance frequency increases up to twice of the initial value while the third resonance frequency decreases until getting very close to the first resonance frequency. This leads to the phenomenon of veering, where both modes get coupled and exchange energy. We demonstrate that by driving both modes nonlinearly and electrostatically near the veering regime, such that the first and third modes exhibit softening and hardening behavior, respectively, sharp roll off from the passband to the stopband is achievable. We show a flat, wide, and tunable bandwidth and center frequency by controlling the electrothermal actuation voltage.

Synchrobetatron resonances

International Nuclear Information System (INIS)

Anon.

1977-01-01

At the 1975 Particle Accelerator Conference it was reported that a class of resonances were observed in SPEAR II that had not appeared before in SPEAR I. These resonances occur when the betatron oscillation wave numbers ν/sub x/ or ν/sub y/ and the synchrotron wave number ν/sub s/ satisfy the relation (ν/sub x,y/ - mν/sub s/) = 5, with m an integer denoting the m/sup th/ satellite. The main difference between SPEAR II and SPEAR I is the value of ν/sub s/, which in SPEAR II is approximately 0.04, an order of magnitude larger than in SPEAR I. An ad hoc meeting was held at the 1975 Particle Accelerator Conference, where details of the SPEAR II results were presented and various possible mechanisms for producing these resonances were discussed. Later, experiments were performed at SPEAR to identify the mechanism believed to be the most likely explanation. Some of the current experimental knowledge and theoretical views on the source of these resonances are presented

Crossing simple resonances

International Nuclear Information System (INIS)

Collins, T.

1985-08-01

A simple criterion governs the beam distortion and/or loss of protons on a fast resonance crossing. Results from numerical integrations are illustrated for simple sextupole, octupole, and 10-pole resonances

Crossing simple resonances

Energy Technology Data Exchange (ETDEWEB)

Collins, T.

1985-08-01

A simple criterion governs the beam distortion and/or loss of protons on a fast resonance crossing. Results from numerical integrations are illustrated for simple sextupole, octupole, and 10-pole resonances.

Uncertainty quantification in resonance absorption

International Nuclear Information System (INIS)

Williams, M.M.R.

2012-01-01

We assess the uncertainty in the resonance escape probability due to uncertainty in the neutron and radiation line widths for the first 21 resonances in 232 Th as given by . Simulation, quadrature and polynomial chaos methods are used and the resonance data are assumed to obey a beta distribution. We find the uncertainty in the total resonance escape probability to be the equivalent, in reactivity, of 75–130 pcm. Also shown are pdfs of the resonance escape probability for each resonance and the variation of the uncertainty with temperature. The viability of the polynomial chaos expansion method is clearly demonstrated.

Iterative resonance self-shielding methods using resonance integral table in heterogeneous transport lattice calculations

International Nuclear Information System (INIS)

Hong, Ser Gi; Kim, Kang-Seog

2011-01-01

This paper describes the iteration methods using resonance integral tables to estimate the effective resonance cross sections in heterogeneous transport lattice calculations. Basically, these methods have been devised to reduce an effort to convert resonance integral table into subgroup data to be used in the physical subgroup method. Since these methods do not use subgroup data but only use resonance integral tables directly, these methods do not include an error in converting resonance integral into subgroup data. The effective resonance cross sections are estimated iteratively for each resonance nuclide through the heterogeneous fixed source calculations for the whole problem domain to obtain the background cross sections. These methods have been implemented in the transport lattice code KARMA which uses the method of characteristics (MOC) to solve the transport equation. The computational results show that these iteration methods are quite promising in the practical transport lattice calculations.

Equivalent-circuit model for the thickness-shear mode resonator with a viscoelastic film near film resonance.

Science.gov (United States)

Martin, S J; Bandey, H L; Cernosek, R W; Hillman, A R; Brown, M J

2000-01-01

We derive a lumped-element, equivalent-circuit model for the thickness-shear mode (TSM) resonator with a viscoelastic film. This modified Butterworth-Van Dyke model includes in the motional branch a series LCR resonator, representing the quartz resonance, and a parallel LCR resonator, representing the film resonance. This model is valid in the vicinity of film resonance, which occurs when the acoustic phase shift across the film is an odd multiple of pi/2 rad. For low-loss films, this model accurately predicts the frequency changes and damping that arise at resonance and is a reasonable approximation away from resonance. Elements of the parallel LCR resonator are explicitly related to film properties and can be interpreted in terms of elastic energy storage and viscous power dissipation. The model leads to a simple graphical interpretation of the coupling between the quartz and film resonances and facilitates understanding of the resulting responses. These responses are compared with predictions from the transmission-line and Sauerbrey models.

Atlas of neutron resonances

CERN Document Server

Mughabghab, Said

2018-01-01

Atlas of Neutron Resonances: Resonance Properties and Thermal Cross Sections Z= 1-60, Sixth Edition, contains an extensive list of detailed individual neutron resonance parameters for Z=1-60, as well as thermal cross sections, capture resonance integrals, average resonance parameters and a short survey of the physics of thermal and resonance neutrons. The long introduction contains: nuclear physics formulas aimed at neutron physicists; topics of special interest such as valence neutron capture, nuclear level density parameters, and s-, p-, and d-wave neutron strength functions; and various comparisons of measured quantities with the predictions of nuclear models, such as the optical model. As in the last edition, additional features have been added to appeal to a wider spectrum of users. These include: spin-dependent scattering lengths that are of interest to solid-state physicists, nuclear physicists and neutron evaluators; calculated and measured Maxwellian average 5-keV and 30-keV capture cross sections o...

Therapeutic Endoscopic Retrograde Cholangiopancreatography in Pediatric Patients With Acute Recurrent and Chronic Pancreatitis: Data From the INSPPIRE (INternational Study group of Pediatric Pancreatitis: In search for a cuRE) Study.

Science.gov (United States)

Troendle, David M; Fishman, Douglas S; Barth, Bradley A; Giefer, Matthew J; Lin, Tom K; Liu, Quin Y; Abu-El-Haija, Maisam; Bellin, Melena D; Durie, Peter R; Freedman, Steven D; Gariepy, Cheryl; Gonska, Tanja; Heyman, Melvin B; Himes, Ryan; Husain, Sohail Z; Kumar, Soma; Lowe, Mark E; Morinville, Veronique D; Ooi, Chee Y; Palermo, Joseph; Pohl, John F; Schwarzenberg, Sarah Jane; Werlin, Steven; Wilschanski, Michael; Zimmerman, M Bridget; Uc, Aliye

2017-07-01

The aim of this study was to characterize utilization and benefit of therapeutic endoscopic retrograde cholangiopancreatography (ERCP) in children with acute recurrent pancreatitis (ARP) or chronic pancreatitis (CP). From August 2012 to February 2015, 301 children with ARP or CP were enrolled in the INSPPIRE (INternational Study group of Pediatric Pancreatitis: In search for a cuRE) study. Physicians reported utilization and benefit of therapeutic ERCP at enrollment. Differences were analyzed using appropriate statistical methods. One hundred seventeen children (38.9%) underwent at least 1 therapeutic ERCP. The procedure was more commonly performed in children with CP compared with those with ARP (65.8% vs 13.5%, P < 0.0001). Utility of therapeutic ERCP was reported to be similar between ARP and CP (53% vs 56%, P = 0.81) and was found to be helpful for at least 1 indication in both groups (53/99 patients [53.5%]). Predictors for undergoing therapeutic ERCP were presence of obstructive factors in ARP and CP, Hispanic ethnicity, or white race in CP. Therapeutic ERCP is frequently utilized in children with ARP or CP and may offer benefit in selected cases, specifically if ductal obstruction is present. Longitudinal studies are needed to clarify the efficacy of therapeutic ERCP and to explore subgroups that might have increased benefit from such intervention.

Giant first-forbidden resonances

International Nuclear Information System (INIS)

Krmpotic, F.; Nakayama, K.; Sao Paulo Univ.; Pio Galeao, A.; Sao Paulo Univ.

1983-01-01

Recent experimental data on first-forbidden charge-exchange resonances are discussed in the framework of a schematic model. We also evaluate the screening of the weak coupling constants induced by both the giant resonances and the δ-isobar. It is shown that the last effect does not depend on the multipolarity of the one-particle moment. Due to the same reason, the fraction of the reaction strength pushed up into the δ-resonance region is always the same regardless of the quantum numbers carried by the excitation. Simple expressions are derived for the dependence of the excitation energies of the first-forbidden giant resonances on the mass number and isospin of the target. The model reproduces consistently both the Gamow-Teller and the first-forbidden resonances. (orig.)

Quantum Proximity Resonances

International Nuclear Information System (INIS)

Heller, E.J.

1996-01-01

It is well known that at long wavelengths λ an s-wave scatterer can have a scattering cross section σ on the order of λ 2 , much larger than its physical size, as measured by the range of its potential. Very interesting phenomena can arise when two or more identical scatterers are placed close together, well within one wavelength. We show that, for a pair of identical scatterers, an extremely narrow p-wave open-quote open-quote proximity close-quote close-quote resonance develops from a broader s-wave resonance of the individual scatterers. A new s-wave resonance of the pair also appears. The relation of these proximity resonances (so called because they appear when the scatterers are close together) to the Thomas and Efimov effects is discussed. copyright 1996 The American Physical Society

Nuclear magnetic resonance

International Nuclear Information System (INIS)

Ethier, R.; Melanson, D.; Peters, T.M.

1983-01-01

Ten years following computerized tomography, a new technique called nuclear magnetic resonance revolutionizes the field of diagnostic imaging. A major advantage of nuclear magnetic resonance is that the danger of radiation is non-existent as compared to computerized tomography. When parts of the human body are subject to radio-frequencies while in a fixed magnetic field, its most detailed structures are revealed. The quality of images, the applications, as well as the indications are forever increasing. Images obtained at the level of the brain and spinal cord through nuclear magnetic resonance supercede those obtained through computerized tomography. Hence, it is most likely that myelography, along with pneumoencephalography will be eliminated as a diagnostic means. It is without a doubt that nuclear magnetic resonance is tomorrow's computerized tomography [fr

Excitation of the Roper resonance and study of higher baryon resonances

International Nuclear Information System (INIS)

Morsch, H.P.; Forschungszentrum Juelich GmbH

1992-01-01

The region of the P 11 resonance N(1440) is investigated in inelastic α-scattering on hydrogen using alpha-particles from Saturne with a beam momentum of 7 GeV/c. In the missing mass spectra of the scattered α-particles two effects are observed, excitation of the projectile, preferentially excited to the Δ-resonance, and excitation of the Roper resonance. The large differential cross sections indicate a structure of a compression mode. From this the compressibility of the nucleon K N may be extracted. The Roper resonance excitation corresponds to a surface mode which may be related to an oscillation of the meson cloud. The other monopole mode which corresponds to a vibration of the valence quarks should lie at about 800 MeV of excitation or above. This is the region of the P 11 (1710 MeV) resonance. Therefore experiments are important to measure the monopole strength in this energy region. Another interesting aspect is the scalar polarizability which can be extracted from inelastic dipole excitations (squeezing modes) as excitation energies above 500 MeV

Neuroaesthetic Resonance

DEFF Research Database (Denmark)

Brooks, Anthony Lewis

2013-01-01

Neuroaesthetic Resonance emerged from a mature body of patient- centered gesture-control research investigating non-formal rehabilitation via ICT-enhanced-Art to question ‘Aesthetic Resonance’. Motivating participation, ludic engagement, and augmenting physical motion in non-formal (fun) treatment...... sessions are achieved via adaptive action-analyzed activities. These interactive virtual environments are designed to empower patients’ creative and/or playful expressions via digital feedback stimuli. Unconscious self- pushing of limits result from innate distractive mechanisms offered by the alternative...... the unencumbered motion-to-computer-generated activities - ‘Music Making’, ‘Painting’, ‘Robotic’ and ‘Video Game’ control. A focus of this position paper is to highlight how Aesthetic Resonance, in this context, relates to the growing body of research on Neuroaesthetics to evolve Neuroaesthetic Resonance....

A Study on Measurement Variations in Resonant Characteristics of Electrostatically Actuated MEMS Resonators

Directory of Open Access Journals (Sweden)

Faisal Iqbal

2018-04-01

Full Text Available Microelectromechanical systems (MEMS resonators require fast, accurate, and cost-effective testing for mass production. Among the different test methods, frequency domain analysis is one of the easiest and fastest. This paper presents the measurement uncertainties in electrostatically actuated MEMS resonators, using frequency domain analysis. The influence of the applied driving force was studied to evaluate the measurement variations in resonant characteristics, such as the natural frequency and the quality factor of the resonator. To quantify the measurement results, measurement system analysis (MSA was performed using the analysis of variance (ANOVA method. The results demonstrate that the resonant frequency ( f r is mostly affected by systematic error. However, the quality (Q factor strongly depends on the applied driving force. To reduce the measurement variations in Q factor, experiments were carried out to study the influence of DC and/or AC driving voltages on the resonator. The results reveal that measurement uncertainties in the quality factor were high for a small electrostatic force.

Transition of EMRIs through resonance: higher order corrections in resonant flux enhancement

Science.gov (United States)

Mihaylov, Deyan; Gair, Jonathan

2017-01-01

Extreme mass ratio inspirals (EMRIs) are candidate events for gravitational wave detection in the millihertz range (by detectors like LISA and eLISA). These events involve a stellar-mass black hole, or a similar compact object, descending into the gravitational field of a supermassive black hole, eventually merging with it. Properties of the inspiraling trajectory away from resonance are well known and have been studied extensively, however little is known about the behaviour of these binary systems at resonance, when the radial and lateral frequencies of the orbit become commensurate. There are two resonance models in the literature, the instantaneous frequency function by Gair, Bender, and Yunes, and the standard two timescales approach devised by Flanagan and Hinderer. We argue that the Gair, Bender and Yunes model provides a valid treatment of the resonance problem and extend this solution to higher order in the size of the on-resonance perturbation. The non-linear differential equations which arise in treating resonances are interesting from a mathematical view point. We present our algorithm for perturbative solutions and the results to third order in the infinitesimal parameter, and discuss the scope of this approach. Deyan Mihaylov is funded by the STFC.

Magnetic resonance imaging apparatus

International Nuclear Information System (INIS)

Ehnholm, G.J.

1991-01-01

This patent describes an electron spin resonance enhanced magnetic resonance (MR) imaging (ESREMRI) apparatus able to generate a primary magnetic field during periods of nuclear spin transition excitation and magnetic resonance signal detection. This allows the generation of ESREMRI images of a subject. A primary magnetic field of a second and higher value generated during periods of nuclear spin transition excitation and magnetic resonance signal detection can be used to generate conventional MR images of a subject. The ESREMRI and native MR images so generated may be combined, (or superimposed). (author)

Acoustic Fano resonators

KAUST Repository

Amin, Muhammad; Farhat, Mohamed; Bagci, Hakan

2014-01-01

The resonances with asymmetric Fano line-shapes were originally discovered in the context of quantum mechanics (U. Fano, Phys. Rev., 124, 1866-1878, 1961). Quantum Fano resonances were generated from destructive interference of a discrete state

Parametric Resonance in Dynamical Systems

CERN Document Server

Nijmeijer, Henk

2012-01-01

Parametric Resonance in Dynamical Systems discusses the phenomenon of parametric resonance and its occurrence in mechanical systems,vehicles, motorcycles, aircraft and marine craft, and micro-electro-mechanical systems. The contributors provide an introduction to the root causes of this phenomenon and its mathematical equivalent, the Mathieu-Hill equation. Also included is a discussion of how parametric resonance occurs on ships and offshore systems and its frequency in mechanical and electrical systems. This book also: Presents the theory and principles behind parametric resonance Provides a unique collection of the different fields where parametric resonance appears including ships and offshore structures, automotive vehicles and mechanical systems Discusses ways to combat, cope with and prevent parametric resonance including passive design measures and active control methods Parametric Resonance in Dynamical Systems is ideal for researchers and mechanical engineers working in application fields such as MEM...

Properties of spiral resonators

International Nuclear Information System (INIS)

Haeuser, J.

1989-10-01

The present thesis deals with the calculation and the study of the application possibilities of single and double spiral resonators. The main aim was the development and the construction of reliable and effective high-power spiral resonators for the UNILAC of the GSI in Darmstadt and the H - -injector for the storage ring HERA of DESY in Hamburg. After the presentation of the construction and the properties of spiral resonators and their description by oscillating-circuit models the theoretical foundations of the bunching are presented and some examples of a rebuncher and debuncher and their influence on the longitudinal particle dynamics are shown. After the description of the characteristic accelerator quantities by means of an oscillating-circuit model and the theory of an inhomogeneous λ/4 line it is shown, how the resonance frequency and the efficiency of single and double spiral resonators can be calculated from the geometrical quantities of the structure. In the following the dependence of the maximal reachable resonator voltage in dependence on the gap width and the surface of the drift tubes is studied. Furthermore the high-power resonators are presented, which were built for the different applications for the GSI in Darmstadt, DESY in Hamburg, and for the FOM Institute in Amsterdam. (orig./HSI) [de

Effect of resonance line shape on precision measurements of nuclear magnetic resonance shifts

International Nuclear Information System (INIS)

Kachurin, A.M.; Smelyanskij, A.Ya.

1986-01-01

Effect of resonance line shape on the systematic error of precision measurements of nuclear magnetic resonance (NMR) shifts of high resolution (on the center of NMR dispersion line) is analysed. Effect of the device resonance line form-function asymmetry is evaluated; the form-function is determined by configuration of the spectrometer magnetic field and enters the convolution, which describes the resonance line form. It is shown that with the increase of the relaxation line width the form-function effect on the measurement error yields to zero. The form-function effect on measurements and correction of a phase angle of NMR detection is evaluated. The method of semiquantitative evaluation of resonance line and NMR spectrometer parameters, guaranteeing the systematic error of the given infinitesimal, is presented

One-loop Renormalization of Resonance Chiral Theory with Scalar and Pseudoscalar Resonances

International Nuclear Information System (INIS)

Rosell, I.

2007-01-01

The divergent part of the generating functional of the Resonance Chiral Theory is evaluated up to one loop when one multiplet of scalar and pseudoscalar resonances are included and interaction terms which couple up to two resonances are considered. Hence we obtain the renormalization of the couplings of the initial Lagrangian and, moreover, the complete list of operators that make this theory finite, at this order

Neutron resonance averaging

International Nuclear Information System (INIS)

Chrien, R.E.

1986-10-01

The principles of resonance averaging as applied to neutron capture reactions are described. Several illustrations of resonance averaging to problems of nuclear structure and the distribution of radiative strength in nuclei are provided. 30 refs., 12 figs

Theory and Applications of Surface Plasmon Resonance, Resonant Mirror, Resonant Waveguide Grating, and Dual Polarization Interferometry Biosensors

Directory of Open Access Journals (Sweden)

Billy W. Day

2010-11-01

Full Text Available Biosensors have been used extensively in the scientific community for several purposes, most notably to determine association and dissociation kinetics, protein-ligand, protein-protein, or nucleic acid hybridization interactions. A number of different types of biosensors are available in the field, each with real or perceived benefits over the others. This review discusses the basic theory and operational arrangements of four commercially available types of optical biosensors: surface plasmon resonance, resonant mirror, resonance waveguide grating, and dual polarization interferometry. The different applications these techniques offer are discussed from experiments and results reported in recently published literature. Additionally, recent advancements or modifications to the current techniques are also discussed.

Micro-machined resonator oscillator

Science.gov (United States)

Koehler, Dale R.; Sniegowski, Jeffry J.; Bivens, Hugh M.; Wessendorf, Kurt O.

1994-01-01

A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a "telemetered sensor beacon" that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20-100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available.

Microelectromechanical resonator and method for fabrication

Science.gov (United States)

Wittwer, Jonathan W [Albuquerque, NM; Olsson, Roy H [Albuquerque, NM

2009-11-10

A method is disclosed for the robust fabrication of a microelectromechanical (MEM) resonator. In this method, a pattern of holes is formed in the resonator mass with the position, size and number of holes in the pattern being optimized to minimize an uncertainty .DELTA.f in the resonant frequency f.sub.0 of the MEM resonator due to manufacturing process variations (e.g. edge bias). A number of different types of MEM resonators are disclosed which can be formed using this method, including capacitively transduced Lame, wineglass and extensional resonators, and piezoelectric length-extensional resonators.

Resonances in QCD

Energy Technology Data Exchange (ETDEWEB)

Lutz, Matthias F.M., E-mail: m.lutz@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Technische Universität Darmstadt, D-64289 Darmstadt (Germany); Lange, Jens Sören, E-mail: Soeren.Lange@exp2.physik.uni-giessen.de [II. Physikalisches Institut, Justus-Liebig-Universität Giessen, D-35392 Giessen (Germany); Pennington, Michael, E-mail: michaelp@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Bettoni, Diego [Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, 44122 Ferrara (Italy); Brambilla, Nora [Physik Department, Technische Universität München, D-85747 Garching (Germany); Crede, Volker [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Eidelman, Simon [Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Budker Istitute of Nuclear Physics SB RAS, Novosibirsk 630090 (Russian Federation); Gillitzer, Albrecht [Institut für Kernphysik, Forschungszentrum Jülich GmbH, D-52425 Jülich (Germany); Gradl, Wolfgang [Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55128 Mainz (Germany); Lang, Christian B. [Institut für Physik, Universität Graz, A-8010 Graz (Austria); Metag, Volker [II. Physikalisches Institut, Justus-Liebig-Universität Giessen, D-35392 Giessen (Germany); Nakano, Takashi [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); and others

2016-04-15

We report on the EMMI Rapid Reaction Task Force meeting ‘Resonances in QCD’, which took place at GSI October 12–14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: • What is needed to understand the physics of resonances in QCD? • Where does QCD lead us to expect resonances with exotic quantum numbers? • What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy–light and heavy–heavy meson systems, those with charm quarks were the focus. This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.

Resonances in QCD

Energy Technology Data Exchange (ETDEWEB)

Lutz, Matthias F. M.; Lange, Jens Sören; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B.; Metag, Volker; Nakano, Takashi; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Stephen L.; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram

2016-04-01

We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015 (Fig.~1). A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions; what is needed to understand the physics of resonances in QCD?; where does QCD lead us to expect resonances with exotic quantum numbers?; and what experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy-light and heavy-heavy meson systems, those with charm quarks were the focus.This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.

Resonant power converters

CERN Document Server

Kazimierczuk, Marian K

2012-01-01

This book is devoted to resonant energy conversion in power electronics. It is a practical, systematic guide to the analysis and design of various dc-dc resonant inverters, high-frequency rectifiers, and dc-dc resonant converters that are building blocks of many of today's high-frequency energy processors. Designed to function as both a superior senior-to-graduate level textbook for electrical engineering courses and a valuable professional reference for practicing engineers, it provides students and engineers with a solid grasp of existing high-frequency technology, while acquainting them wit

Writing with resonance

DEFF Research Database (Denmark)

Meier, Ninna; Wegener, Charlotte

2017-01-01

In this article, we explore what organization and management scholars can do to write with resonance and to facilitate an emotional, bodily, or in other ways sensory connection between the text and the reader. We propose that resonance can be relevant for organization and management scholars in two......, and thus bring forward the field of research in question. We propose that writing with resonance may be a way to further the impact of academic work by extending the modalities with which our readers can relate to and experience our work....

Multiquark Resonances

CERN Document Server

Esposito, A.; Polosa, A.D.

2016-01-01

Multiquark resonances are undoubtedly experimentally observed. The number of states and the amount of details on their properties has been growing over the years. It is very recent the discovery of two pentaquarks and the confirmation of four tetraquarks, two of which had not been observed before. We mainly review the theoretical understanding of this sector of particle physics phenomenology and present some considerations attempting a coherent description of the so called X and Z resonances. The prominent problems plaguing theoretical models, like the absence of selection rules limiting the number of states predicted, motivate new directions in model building. Data are reviewed going through all of the observed resonances with particular attention to their common features and the purpose of providing a starting point to further research.

Guided mode resonance in planar metamaterials consisting of two ring resonators with different sizes

International Nuclear Information System (INIS)

Yu Zhen; Che Hang; Liu Jianjun; Jing Xufeng; Li Xiangjun; Hong Zhi

2017-01-01

We proposed and experimentally investigated a two-ring-resonator composed planar hybrid metamaterial (MM), in which the spectra of guided mode resonance (GMR) and Fano resonance or EIT-like response induced by coherent interaction between MM resonance and GMR can be easily controlled by the size of the two rings in the terahertz regime. Furthermore, a four-ring-resonator composed MM for polarization-insensitive GMRs was demonstrated, where GMRs of both TE and TM modes are physically attributed to the diffraction coupling by two ±45° tilting gratings. Such kind of device has great potential in ultra-sensitive label-free sensors, filters, or slow light based devices. (paper)

Reflection effect of localized absorptive potential on non-resonant and resonant tunneling

International Nuclear Information System (INIS)

Rubio, A.; Kumar, N.

1992-06-01

The reflection due to absorptive potential (-iV i ) for resonant and non-resonant tunneling has been considered. We show that the effect of reflection leads to a non-monotonic dependence of absorption on the strength V i with a maximum absorption of typically 0.5. This has implications for the operation of resonant tunneling devices. General conceptual aspects of absorptive potentials are discussed. (author). 9 refs, 2 figs

Stochastic resonance and coherence resonance in groundwater-dependent plant ecosystems.

Science.gov (United States)

Borgogno, Fabio; D'Odorico, Paolo; Laio, Francesco; Ridolfi, Luca

2012-01-21

Several studies have shown that non-linear deterministic dynamical systems forced by external random components can give rise to unexpectedly regular temporal behaviors. Stochastic resonance and coherence resonance, the two best known processes of this type, have been studied in a number of physical and chemical systems. Here, we explore their possible occurrence in the dynamics of groundwater-dependent plant ecosystems. To this end, we develop two eco-hydrological models, which allow us to demonstrate that stochastic and coherence resonance may emerge in the dynamics of phreatophyte vegetation, depending on their deterministic properties and the intensity of external stochastic drivers. Copyright © 2011 Elsevier Ltd. All rights reserved.

A New Look at an Old Activity: Resonance Tubes Used to Teach Resonance

Science.gov (United States)

Nelson, Jim; Nelson, Jane

2017-01-01

There are several variations of resonance laboratory activities used to determine the speed of sound. This is "not" one of them. This activity uses the resonance tube idea to teach "resonance," not to verify the speed of sound. Prior to this activity, the speed of sound has already been measured using computer sound-sensors and…

Fundamentals of nanomechanical resonators

CERN Document Server

Schmid, Silvan; Roukes, Michael Lee

2016-01-01

This authoritative book introduces and summarizes the latest models and skills required to design and optimize nanomechanical resonators, taking a top-down approach that uses macroscopic formulas to model the devices. The authors cover the electrical and mechanical aspects of nano electromechanical system (NEMS) devices. The introduced mechanical models are also key to the understanding and optimization of nanomechanical resonators used e.g. in optomechanics. Five comprehensive chapters address: The eigenmodes derived for the most common continuum mechanical structures used as nanomechanical resonators; The main sources of energy loss in nanomechanical resonators; The responsiveness of micro and nanomechanical resonators to mass, forces, and temperature; The most common underlying physical transduction mechanisms; The measurement basics, including amplitude and frequency noise. The applied approach found in this book is appropriate for engineering students and researchers working with micro and nanomechanical...

Resonantly scattering crystals and surfaces

International Nuclear Information System (INIS)

Gunn, J.M.F.; Mahon, P.J.

1990-12-01

We examine coherence effects from forming a crystal of resonant scatterers by generalising the Fano model for autoionising resonances in electron scattering from atoms to a lattice of such scatterers. (We have in mind the case of neutron scattering from nuclei.) We solve this problem to yield two branches to the dispersion relation for the neutron in general and three when the resonance coincides with a Brillouin Zone boundary. The 'width' of the resonance is enhanced over the isolated nucleus, the best candidate for observation being the 2eV 185 Re resonance near the Bragg condition. We use these results to calculate the reflection coefficient from a surface, revealing total external reflection near resonance. We discuss experimental feasibility in both the neutron and electron cases. (author)

Progressive and resonant wave helices application to electron paramagnetic resonance; Helices a ondes progressives et resonnantes application a la resonance paramagnetique electronique

Energy Technology Data Exchange (ETDEWEB)

Volino, F [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-07-01

We show that helices can be used as resonant systems. Their properties are theoretically and experimentally studied. We describe resonant helices for electron paramagnetic resonance in X-band and develop a comparison between their sensitivity and the sensitivity of a normal resonant cavity. For cylindrical samples less than 3 mm diameter, the helix is more sensitive and can produce more intense microwave magnetic fields. (author) [French] Il est montre que les helices peuvent etre utilisees comme systeme resonnant. Leurs proprietes sont discutees theoriquement et experimentalement. Des helices resonnantes en bande X pour la resonance paramagnetique electronique sont decrites et leur sensibilite est comparee a celle des cavites resonnantes. Pour des echantillons cylindriques de moins de 3 mm de diametre, l'helice est plus sensible et peut produire des champs magnetiques hyper fins plus intenses. (auteur)

Shape resonances in molecular fields

International Nuclear Information System (INIS)

Dehmer, J.L.

1984-01-01

A shape resonance is a quasibound state in which a particle is temporarily trapped by a potential barrier (i.e., the shape of the potential), through which it may eventually tunnel and escape. This simple mechanism plays a prominent role in a variety of excitation processes in molecules, ranging from vibrational excitation by slow electrons to ionization of deep core levels by x-rays. Moreover, their localized nature makes shape resonances a unifying link between otherwise dissimilar circumstances. One example is the close connection between shape resonances in electron-molecule scattering and in molecular photoionization. Another is the frequent persistence of free-molecule shape resonant behavior upon adsorption on a surface or condensation into a molecular solid. The main focus of this article is a discussion of the basic properties of shape resonances in molecular fields, illustrated by the more transparent examples studied over the last ten years. Other aspects to be discussed are vibrational effects of shape resonances, connections between shape resonances in different physical settings, and examples of shape resonant behavior in more complex cases, which form current challenges in this field

Pediatric magnetic resonance imaging

International Nuclear Information System (INIS)

Cohen, M.D.

1986-01-01

This book defines the current clinical potential of magnetic resonance imaging and focuses on direct clinical work with pediatric patients. A section dealing with the physics of magnetic resonance imaging provides an introduction to enable clinicians to utilize the machine and interpret the images. Magnetic resonance imaging is presented as an appropriate imaging modality for pediatric patients utilizing no radiation

Resonant thermonuclear reaction rate

International Nuclear Information System (INIS)

Haubold, H.J.; Mathai, A.M.

1986-01-01

Basic physical principles for the resonant and nonresonant thermonuclear reaction rates are applied to find their standard representations for nuclear astrophysics. Closed-form representations for the resonant reaction rate are derived in terms of Meijer's G-function. Analytic representations of the resonant and nonresonant nuclear reaction rates are compared and the appearance of Meijer's G-function is discussed in physical terms

Piezoelectric MEMS resonators

CERN Document Server

Piazza, Gianluca

2017-01-01

This book introduces piezoelectric microelectromechanical (pMEMS) resonators to a broad audience by reviewing design techniques including use of finite element modeling, testing and qualification of resonators, and fabrication and large scale manufacturing techniques to help inspire future research and entrepreneurial activities in pMEMS. The authors discuss the most exciting developments in the area of materials and devices for the making of piezoelectric MEMS resonators, and offer direct examples of the technical challenges that need to be overcome in order to commercialize these types of devices. Some of the topics covered include: Widely-used piezoelectric materials, as well as materials in which there is emerging interest Principle of operation and design approaches for the making of flexural, contour-mode, thickness-mode, and shear-mode piezoelectric resonators, and examples of practical implementation of these devices Large scale manufacturing approaches, with a focus on the practical aspects associate...

Nonlinear elasticity in resonance experiments

Science.gov (United States)

Li, Xun; Sens-Schönfelder, Christoph; Snieder, Roel

2018-04-01

Resonant bar experiments have revealed that dynamic deformation induces nonlinearity in rocks. These experiments produce resonance curves that represent the response amplitude as a function of the driving frequency. We propose a model to reproduce the resonance curves with observed features that include (a) the log-time recovery of the resonant frequency after the deformation ends (slow dynamics), (b) the asymmetry in the direction of the driving frequency, (c) the difference between resonance curves with the driving frequency that is swept upward and downward, and (d) the presence of a "cliff" segment to the left of the resonant peak under the condition of strong nonlinearity. The model is based on a feedback cycle where the effect of softening (nonlinearity) feeds back to the deformation. This model provides a unified interpretation of both the nonlinearity and slow dynamics in resonance experiments. We further show that the asymmetry of the resonance curve is caused by the softening, which is documented by the decrease of the resonant frequency during the deformation; the cliff segment of the resonance curve is linked to a bifurcation that involves a steep change of the response amplitude when the driving frequency is changed. With weak nonlinearity, the difference between the upward- and downward-sweeping curves depends on slow dynamics; a sufficiently slow frequency sweep eliminates this up-down difference. With strong nonlinearity, the up-down difference results from both the slow dynamics and bifurcation; however, the presence of the bifurcation maintains the respective part of the up-down difference, regardless of the sweep rate.

Auxiliary resonant DC tank converter

Science.gov (United States)

Peng, Fang Z.

2000-01-01

An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

Influence of attention alternation on movement-related cortical potentials in healthy individuals and stroke patients

DEFF Research Database (Denmark)

Aliakbaryhosseinabadi, Susan; Kostic, Vladimir; Pavlovic, Aleksandra

2017-01-01

Objective In this study, we analyzed the influence of artificially imposed attention variations using the auditory oddball paradigm on the cortical activity associated to motor preparation/execution. Methods EEG signals from Cz and its surrounding channels were recorded during three sets of ankle...... and accuracy deteriorated with attention diversion. Conclusion Attention diversion has a significant influence on MRCP features and detection parameters, although these changes were counteracted by the application of the laplacian method. Significance Brain–computer interfaces for neuromodulation that use...... the MRCP as the control signal are robust to changes in attention. However, attention must be monitored since it plays a key role in plasticity induction. Here we demonstrate that this can be achieved using the single channel Cz....

Resonance control of mid-infrared metamaterials using arrays of split-ring resonator pairs

KAUST Repository

Yue, Weisheng

2016-01-11

We present our design, fabrication and characterization of resonance-controllable metamaterials operating at mid-infrared wavelengths. The metamaterials are composed of pairs of back-to-back or face-to-face U-shape split-ring resonators (SRRs). Transmission spectra of the metamaterials are measured using Fourier-transform infrared spectroscopy. The results show that the transmission resonance is dependent on the distance between the two SRRs in each SRR pair. The dips in the transmission spectrum shift to shorter wavelengths with increasing distance between the two SRRs for both the back-to-back and face-to-face SRR pairs. The position of the resonance dips in the spectrum can hence be controlled by the relative position of the SRRs. This mechanism of resonance control offers a promising way of developing metamaterials with tunability for optical filters and bio/chemical sensing devices in integrated nano-optics.

Resonance control of mid-infrared metamaterials using arrays of split-ring resonator pairs

KAUST Repository

Yue, Weisheng; Wang, Zhihong; Whittaker, John; Schedin, Fredrik; Wu, Zhipeng; Han, Jiaguang

2016-01-01

We present our design, fabrication and characterization of resonance-controllable metamaterials operating at mid-infrared wavelengths. The metamaterials are composed of pairs of back-to-back or face-to-face U-shape split-ring resonators (SRRs). Transmission spectra of the metamaterials are measured using Fourier-transform infrared spectroscopy. The results show that the transmission resonance is dependent on the distance between the two SRRs in each SRR pair. The dips in the transmission spectrum shift to shorter wavelengths with increasing distance between the two SRRs for both the back-to-back and face-to-face SRR pairs. The position of the resonance dips in the spectrum can hence be controlled by the relative position of the SRRs. This mechanism of resonance control offers a promising way of developing metamaterials with tunability for optical filters and bio/chemical sensing devices in integrated nano-optics.

Short-circuit protection of LLC resonant converter using voltages across resonant tank elements

Directory of Open Access Journals (Sweden)

Denys Igorovych Zaikin

2015-06-01

Full Text Available This paper describes two methods for the short-circuit protection of the LLC resonant converter. One of them uses the voltage across the capacitor and the other uses the voltage across the inductor of the resonant tank. These voltages can be processed (integrated or differentiated to recover the resonant tank current. The two circuits illustrated in the described methods make it possible to develop a robust LLC converter design and to avoid using lossy current measurement elements, such as a shunt resistor or current transformer. The methods also allow measuring resonant tank current without breaking high-current paths and connecting the measuring circuit in parallel with the inductor or capacitor of the resonant tank. Practical implementations of these indirect current measurements have been experimentally tested for the short-circuit protection of the 1600 W LLC converter.

Multiquark resonant states

International Nuclear Information System (INIS)

Shahbazian, B.A.

1982-01-01

The invariant mass spectra of forty nine hadronic systems with hypercharge, strangeness and baryon number, varied in wide limits have been studied. Resonance peaks have been found in the invariant mass spectra of Y 2 and #betta#pπ 2495 MeV/c 2 resonant states. Three more candidates for anti qq 4 states were found #bettaπ# + π + : 1705, 2072, 2605 MeV/c 2 . The masses of all these candidates are in good agreement with Bag Model predictions. A hypercharge selection rule is suggested: ''The hypercharge of hadronic resonances in weak gravitational fields cannot exceed one Y <= 1

Progressive and resonant wave helices application to electron paramagnetic resonance; Helices a ondes progressives et resonnantes application a la resonance paramagnetique electronique

Energy Technology Data Exchange (ETDEWEB)

Volino, F. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1969-07-01

We show that helices can be used as resonant systems. Their properties are theoretically and experimentally studied. We describe resonant helices for electron paramagnetic resonance in X-band and develop a comparison between their sensitivity and the sensitivity of a normal resonant cavity. For cylindrical samples less than 3 mm diameter, the helix is more sensitive and can produce more intense microwave magnetic fields. (author) [French] Il est montre que les helices peuvent etre utilisees comme systeme resonnant. Leurs proprietes sont discutees theoriquement et experimentalement. Des helices resonnantes en bande X pour la resonance paramagnetique electronique sont decrites et leur sensibilite est comparee a celle des cavites resonnantes. Pour des echantillons cylindriques de moins de 3 mm de diametre, l'helice est plus sensible et peut produire des champs magnetiques hyper fins plus intenses. (auteur)

Ramifide resonators for cyclotrons

International Nuclear Information System (INIS)

Smirnov, Yu.V.

2000-01-01

The resonators with the conductors ramified form for cyclotrons are systematized and separated into the self-contained class - the ramified resonators for cyclotrons (Carr). The ramified resonators are compared with the quarter-wave and half-wave nonramified resonators, accomplished from the transmitting lines fragments. The CRR are classified into two types: ones with the additional structural element, switched in parallel and in series. The CRR may include several additional structural elements. The CRR calculations may be concluded by analytical methods - the method of matrix calculation or the method of telegraph equations and numerical methods - by means of the ISFEL3D, MAFIA and other programs [ru

Magnetic Resonance Sensors

Directory of Open Access Journals (Sweden)

Robert H. Morris

2014-11-01

Full Text Available Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. With beginnings in borehole logging for the petro-chemical industry Magnetic Resonance sensors have been applied to fields as varied as online process monitoring for food manufacture and medical point of care diagnostics. This great diversity is seeing exciting developments in magnetic resonance sensing technology published in application specific journals where they are often not seen by the wider sensor community. It is clear that there is enormous interest in magnetic resonance sensors which represents a significant growth area. The aim of this special edition of Sensors was to address the wide distribution of relevant articles by providing a forum to disseminate cutting edge research in this field in a single open source publication.[...

Children's (Pediatric) Magnetic Resonance Imaging

Science.gov (United States)

... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

Multi-frequency modes in superconducting resonators: Bridging frequency gaps in off-resonant couplings

Science.gov (United States)

Andersen, Christian Kraglund; Mølmer, Klaus

2015-03-01

A SQUID inserted in a superconducting waveguide resonator imposes current and voltage boundary conditions that makes it suitable as a tuning element for the resonator modes. If such a SQUID element is subject to a periodically varying magnetic flux, the resonator modes acquire frequency side bands. We calculate the multi-frequency eigenmodes and these can couple resonantly to physical systems with different transition frequencies and this makes the resonator an efficient quantum bus for state transfer and coherent quantum operations in hybrid quantum systems. As an example of the application, we determine their coupling to transmon qubits with different frequencies and we present a bi-chromatic scheme for entanglement and gate operations. In this calculation, we obtain a maximally entangled state with a fidelity F = 95 % . Our proposal is competitive with the achievements of other entanglement-gates with superconducting devices and it may offer some advantages: (i) There is no need for additional control lines and dephasing associated with the conventional frequency tuning of qubits. (ii) When our qubits are idle, they are far detuned with respect to each other and to the resonator, and hence they are immune to cross talk and Purcell-enhanced decay.

Design of a dielectric resonator receive array at 7 Tesla using detunable ceramic resonators

Science.gov (United States)

Ruytenberg, Thomas; Webb, Andrew G.

2017-11-01

Ceramic-based dielectric resonators can be used for high frequency magnetic resonance imaging and microscopy. When used as elements in a transmit array, the intrinsically low inter-element coupling allows flexibility in designing different geometric arrangements for different regions-of-interest. However, without being able to detune such resonators, they cannot be used as elements in a receive-only array. Here, we propose and implement a method, based on mode-disruption, for detuning ceramic-based dielectric resonators to enable them to be used as receive-only elements.

Controlling Parametric Resonance

DEFF Research Database (Denmark)

Galeazzi, Roberto; Pettersen, Kristin Ytterstad

2012-01-01

the authors review the conditions for the onset of parametric resonance, and propose a nonlinear control strategy in order to both induce the resonant oscillations and to stabilize the unstable motion. Lagrange’s theory is used to derive the dynamics of the system and input–output feedback linearization...

Magnetic Resonance Imaging (MRI) -- Head

Science.gov (United States)

... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... News Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging ( ... the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a ...

Magnetic resonance angiography (MRA)

International Nuclear Information System (INIS)

Arlart, I.P.; Guhl, L.

1992-01-01

An account is given in this paper of the physical and technical principles underlying the 'time-of-flight' technique for imaging of vessels by magnetic resonance tomography. Major indications for the new procedure of magnetic resonance angiography at present are intracerebral and extracerebral vessels, with digital subtraction angiography quite often being required to cope with minor alterations (small aneurysms, small occlusions). Magnetic resonance angiography and digital subtraction angiography are compared to each other for advantages and disadvantages. Basically, replacement of radiological angiography by magnetic resonance angiography appears to be possible only within limits, since X-ray diagnostics primarily provides morphological information about vessels, whereas flow dynamics is visualized by the 'time-of-flight' technique. (orig.) [de

A resonant dc-dc power converter assembly

DEFF Research Database (Denmark)

2015-01-01

The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the s......The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor...... of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or forcing substantially 0 degree phase shift, between corresponding resonant voltage waveforms of the first...

Probabilistic interpretation of resonant states

Indian Academy of Sciences (India)

The present paper reviews the basic definition of the resonant state in quantum ... We show that particles leak from the central region in the resonant state. The ..... The basic idea is as follows (figure 4): Consider a resonant eigenstate. Φn(x ...

Quantum Graphs And Their Resonance Properties

International Nuclear Information System (INIS)

Lipovsky, J.

2016-01-01

In the current review, we study the model of quantum graphs. We focus mainly on the resonance properties of quantum graphs. We define resolvent and scattering resonances and show their equivalence. We present various results on the asymptotics of the number of resolvent resonances in both non-magnetic and magnetic quantum graphs and find bounds on the coefficient by the leading term of the asymptotics. We explain methods how to find the spectral and resonance condition. Most of the notions and theorems are illustrated in examples. We show how to find resonances numerically and, in a simple example, we find trajectories of resonances in the complex plane. We discuss Fermi’s golden rule for quantum graphs and distribution of the mean intensity for the topological resonances. (author)

Predictive factors of oxygen desaturation of patients submitted to endoscopic retrograde cholangiopancreatography under conscious sedation Fatores preditivos de dessaturação de oxigênio de pacientes submetidos a colangiopancreatografia endoscópica retrógrada sob sedação consciente

Directory of Open Access Journals (Sweden)

Suzana Müller

2004-09-01

Full Text Available BACKGROUND AND AIMS: Hypoxemia can occur during endoscopic retrograde cholangiopancreatography probably induced by the analgesia and sedation done. Moreover the patient’s prone position difficults the adequate ventilation. The hypoxemia and hypoventilation may not be noticed by nursing staff. A transversal study was used to investigate possible predictive factors of oxygen desaturation in sedated patients with midazolam associated to meperidine undergoing endoscopic retrograde cholangiopancreatography. PATIENTS AND METHODS: A total of 186 patients were monitored with continuous pulse oximetry. Poisson regression was used to measure the independent effect of each factor adjusted for effects of each of the other factors. The variables studied were: age, gender, hematocrit and hemoglobin levels, scopolamine use, diagnostic or therapeutic exam, American Society of Anesthesiologists Scores (ASA, duration time of exam, sedative used midazolam in the average of 0.07 mg/kg and analgesic drug meperidine in the average of 0.7 mg/kg that was titrated according patient’s reaction. RESULTS: No desaturation was found in 113 (60.8% patients, mild desaturation (SpO2 60 years old and ASA score III. The duration of exam was barely significant for desaturation. CONCLUSIONS:The variables of age of 60 years old or more, and ASA III score are identified as increased risk for desaturation for patients who undergo endoscopic retrograde cholangiopancreatography under conscious sedation. Long time of exam suggests the patient oxygen desaturate. Such patients require very close monitoring to desaturation and hypoventilation by the assistants and nursing staff alerting to respiratory depression. The use of pulse oximeter and asking for deep breaths during the exam helps to diminish such risks.RACIONAL: A hipoxemia pode ocorrer durante a colangiopancreatografia endoscópica retrógrada, provavelmente induzida pela analgesia e sedação realizadas, além da posição do

Classification of Hand Grasp Kinetics and Types Using Movement-Related Cortical Potentials and EEG Rhythms

Directory of Open Access Journals (Sweden)

Mads Jochumsen

2017-01-01

Full Text Available Detection of single-trial movement intentions from EEG is paramount for brain-computer interfacing in neurorehabilitation. These movement intentions contain task-related information and if this is decoded, the neurorehabilitation could potentially be optimized. The aim of this study was to classify single-trial movement intentions associated with two levels of force and speed and three different grasp types using EEG rhythms and components of the movement-related cortical potential (MRCP as features. The feature importance was used to estimate encoding of discriminative information. Two data sets were used. 29 healthy subjects executed and imagined different hand movements, while EEG was recorded over the contralateral sensorimotor cortex. The following features were extracted: delta, theta, mu/alpha, beta, and gamma rhythms, readiness potential, negative slope, and motor potential of the MRCP. Sequential forward selection was performed, and classification was performed using linear discriminant analysis and support vector machines. Limited classification accuracies were obtained from the EEG rhythms and MRCP-components: 0.48±0.05 (grasp types, 0.41±0.07 (kinetic profiles, motor execution, and 0.39±0.08 (kinetic profiles, motor imagination. Delta activity contributed the most but all features provided discriminative information. These findings suggest that information from the entire EEG spectrum is needed to discriminate between task-related parameters from single-trial movement intentions.

Magnetic Resonance Imaging (MRI) -- Head

Medline Plus

Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

Observation of the M1 giant resonance by resonance averaging in 106Pd

International Nuclear Information System (INIS)

Kopecky, J.

1987-01-01

An investigation of capture of 2 keV and 24 keV neutrons in a 105 Pd target resulted in resonance-averaged intensities of primary gamma rays with energies between 5.2 and 9.5 MeV. From these intensities the gamma ray strength functions have been evaluated for E1, M1 and E2 radiation and compared with predictions of the giant resonance theory. The inclusion of an energy dependent spreading width for the E1 giant resonance is necessary. The energy distribution of M1 reduced strength is consistent with an interpretation of a broad resonance around 8.8 MeV. E2 data agrees satisfactorily with the giant extrapolation. (orig.)

Observation of ferromagnetic resonance in a microscopic sample using magnetic resonance force microscopy

International Nuclear Information System (INIS)

Zhang, Z.; Hammel, P.C.; Wigen, P.E.

1996-01-01

We report the observation of a ferromagnetic resonance signal arising from a microscopic (∼20μmx40μm) particle of thin (3μm) yttrium iron garnet film using magnetic resonance force microscopy (MRFM). The large signal intensity in the resonance spectra suggests that MRFM could become a powerful microscopic ferromagnetic resonance technique with a micron or sub-micron resolution. We also observe a very strong nonresonance signal which occurs in the field regime where the sample magnetization readily reorients in response to the modulation of the magnetic field. This signal will be the main noise source in applications where a magnet is mounted on the cantilever. copyright 1996 American Institute of Physics

Determination of space-energy distribution of resonance neutrons in reactor lattice cell and calculation of resonance integrals

International Nuclear Information System (INIS)

Zmijarevic, I.

1980-01-01

Space-energy distribution of resonance neutrons in reactor lattice cell was determined by solving the Boltzmann equation by spherical harmonics method applying P-3 approximation. Computer code SPLET used for these calculations is described. Resonance absorption and calculation of resonance integrals are described as well. Effective resonance integral values for U-238 resonance at 6.7 Ev are calculated for heavy water reactor cell with metal, oxide and carbide fuel elements

Membrane metamaterial resonators with a sharp resonance: A comprehensive study towards practical terahertz filters and sensors

Directory of Open Access Journals (Sweden)

Yongyao Chen

2012-06-01

Full Text Available We investigate the resonant properties of high quality-factor membrane-based metamaterial resonators functioning in the terahertz regime. A number of factors, including the resonator geometry, dielectric loss, and most importantly the membrane thickness are found to extensively influence the resonance strength and quality factor of the sharp resonance. Further studies on the membrane thickness-dependent-sensitivity for sensing applications reveal that high quality-factor membrane metamaterials with a moderate thickness ranging from 10 to 50 μm are the most promising option towards developing realistic integrated terahertz filters and sensors.

Fluctuation Reduction in a Si Micromechanical Resonator Tuned to Nonlinear Internal Resonance

Science.gov (United States)

Strachan, B. Scott; Czaplewski, David; Chen, Changyao; Dykman, Mark; Lopez, Daniel; Shaw, Steven

2015-03-01

We describe experimental and theoretical results on an unusual behavior of fluctuations when the system exhibits internal resonance. We study the fundamental flexural mode (FFM) of a Si microbeam. The FFM is electrically actuated and detected. It is resonantly nonlinearly coupled to another mode, which is not directly accessible and has a frequency nearly three times the FFM frequency. Both the FFM and the passive mode have long lifetimes. We find that the passive mode can be a ``sink'' for fluctuations of the FFM. This explains the recently observed dramatic decrease of these fluctuations at nonlinear resonance. The re-distribution of the vibration amplitudes and the fluctuations is reminiscent of what happens at level anti-crossing in quantum mechanics. However, here it is different because of interplay of the dependence of the vibration frequency of the FFM on its amplitude due to internal nonlinearity and the nonlinear resonance with the passive mode. We study both the response of the system to external resonant driving and also the behavior of the system in the presence of a feedback loop. The experimental and theoretical results are in good agreement.

Imaging in the diagnosis of chronic pancreatitis

Directory of Open Access Journals (Sweden)

Vasile D. Balaban

2014-12-01

Full Text Available Chronic pancreatitis is characterised by progressive and irreversible damage of the pancreatic parenchyma and ductal system, which leads to chronic pain, loss of endocrine and exocrine functions. Clinically, pancreatic exocrine insufficiency becomes apparent only after 90% of the parenchima has been lost. Despite the simple definition, diagnosing chronic pancreatitis remains a challenge, especially for early stage disease. Because pancreatic function tests can be normal until late stages and have significant limitations, there is an incresing interest in the role of imaging techniques for the diagnosis of chronic pancreatitis. In this article we review the utility and accuracy of different imaging methods in the diagnosis of chronic pancreatitis, focusing on the role of advanced imaging (magnetic resonance imaging, endoscopic retrograde cholangiopancreatography and endoscopic ultrasound.

The thermal neutron absorption cross-sections, resonance integrals and resonance parameters of silicon and its stable isotopes

International Nuclear Information System (INIS)

Story, J.S.

1969-09-01

The data available up to the end of November 1968 on the thermal neutron absorption cross-sections, resonance absorption integrals, and resonance parameters of silicon and its stable isotopes are collected and discussed. Estimates are given of the mean spacing of the energy levels of the compound nuclei near the neutron binding energy. It is concluded that the thermal neutron absorption cross-section and resonance absorption integral of natural silicon are not well established. The data on these two parameters are somewhat correlated, and three different assessments of the resonance integral are presented which differ over-all by a factor of 230. Many resonances have been detected by charged particle reactions which have not yet been observed in neutron cross-section measurements. One of these resonances of Si 2 8, at E n = 4 ± 5 keV might account for the large resonance integral which is derived, very uncertainly, from integral data. The principal source of the measured resonance integral of Si 3 0 has not yet been located. The thermal neutron absorption cross-section of Si 2 8 appears to result mainly from a negative energy resonance, possibly the resonance at E n = - 59 ± 5 keV detected by the Si 2 8 (d,p) reaction. (author)

Q-Boosted Optomechanical Resonators

Science.gov (United States)

2015-11-18

type a knob for optical Qo, where the inability to smooth etched nitride sidewall surfaces relegates OMO’s using it to Qo’s on the order of...6: Operation of an RP-OMO. As the ring resonator coupled to tapered fiber in (a) displaces by ∂r, the optical path length change produces the shift...frequency 0, B input pump laser field, tot the total optical resonator damping, ext the coupling between optical resonator and the tapered fiber

Higgs-photon resonances

Energy Technology Data Exchange (ETDEWEB)

Dobrescu, Bogdan A.; Fox, Patrick J.; Kearney, John [Fermilab, Theoretical Physics Department, Batavia, IL (United States)

2017-10-15

We study models that produce a Higgs boson plus photon (h{sup 0}γ) resonance at the LHC. When the resonance is a Z{sup '} boson, decays to h{sup 0}γ occur at one loop. If the Z{sup '} boson couples at tree level to quarks, then the h{sup 0}γ branching fraction is typically of order 10{sup -5} or smaller. Nevertheless, there are models that would allow the observation of Z{sup '} → h{sup 0}γ at √(s) = 13 TeV with a cross section times branching fraction larger than 1 fb for a Z{sup '} mass in the 200-450 GeV range, and larger than 0.1 fb for a mass up to 800 GeV. The one-loop decay of the Z{sup '} into lepton pairs competes with h{sup 0}γ, even if the Z{sup '} couplings to leptons vanish at tree level. We also present a model in which a Z{sup '} boson decays into a Higgs boson and a pair of collimated photons, mimicking an h{sup 0}γ resonance. In this model, the h{sup 0}γ resonance search would be the discovery mode for a Z{sup '} as heavy as 2 TeV. When the resonance is a scalar, although decay to h{sup 0}γ is forbidden by angular momentum conservation, the h{sup 0} plus collimated photons channel is allowed. We comment on prospects of observing an h{sup 0}γ resonance through different Higgs decays, on constraints from related searches, and on models where h{sup 0} is replaced by a nonstandard Higgs boson. (orig.)

Mode Coupling and Nonlinear Resonances of MEMS Arch Resonators for Bandpass Filters

KAUST Repository

Hajjaj, Amal Z.; Hafiz, Md Abdullah Al; Younis, Mohammad I.

2017-01-01

the passband to the stopband. The concept is demonstrated based on an electrothermally tuned and electrostatically driven MEMS arch resonator operated in air. The in-plane resonator is fabricated from a silicon-on-insulator wafer with a deliberate curvature

Geometrical optics model of Mie resonances

Science.gov (United States)

Roll; Schweiger

2000-07-01

The geometrical optics model of Mie resonances is presented. The ray path geometry is given and the resonance condition is discussed with special emphasis on the phase shift that the rays undergo at the surface of the dielectric sphere. On the basis of this model, approximate expressions for the positions of first-order resonances are given. Formulas for the cavity mode spacing are rederived in a simple manner. It is shown that the resonance linewidth can be calculated regarding the cavity losses. Formulas for the mode density of Mie resonances are given that account for the different width of resonances and thus may be adapted to specific experimental situations.

Selection criteria for preoperative endoscopic retrograde cholangiopancreatography before laparoscopic cholecystectomy and endoscopic treatment of bile duct stones: Results of a retrospective, single center study between 1996-2002

Science.gov (United States)

Lakatos, Laszlo; Mester, Gabor; Reti, Gyorgy; Nagy, Attila; Lakatos, Peter Laszlo

2004-01-01

AIM: The optimal treatment for bile duct stones (in terms of cost, complications and accuracy) is unclear. The aim of our study was to determine the predictive factors for preoperative endoscopic retrograde cholangiopancreatography (ERCP). METHODS: Patients undergoing preoperative ERCP ( ≤ 90 d before laparoscopic cholecystectomy) were evaluated in this retrospective study from the 1st of January 1996 to the 31st of December 2002. The indications for ERCP were elevated serum bilirubin, elevated liver function tests (LFT), dilated bile duct ( ≥ 8 mm) and/or stone at US examination, coexisting acute pancreatitis and/or acute pancreatitis or jaundice in patient’s history. Suspected prognostic factors and the combination of factors were compared to the result of ERCP. RESULTS: Two hundred and six preoperative ERCPs were performed during the observed period. The rate of successful cannulation for ERC was (97.1%). Bile duct stones were detected in 81 patients (39.3%), and successfully removed in 79 (97.5%). The number of prognostic factors correlated with the presence of bile duct stones. The positive predictive value for one prognostic factor was 1.2%, for two 43%, for three 72.5%, for four or more 91.4%. CONCLUSION: Based on our data preoperative ERCP is highly recommended in patients with three or more positive factors (high risk patients). In contrast, ERCP is not indicated in patients with zero or one factor (low risk patients). Preoperative ERCP should be offered to patients with two positive factors (moderate risk patients), however the practice should also be based on the local conditions (e.g. skill of the endoscopist, other diagnostic tools). PMID:15526372

Symmetry and resonance in Hamiltonian systems

NARCIS (Netherlands)

Tuwankotta, J.M.; Verhulst, F.

2000-01-01

In this paper we study resonances in two degrees of freedom, autonomous, hamiltonian systems. Due to the presence of a symmetry condition on one of the degrees of freedom, we show that some of the resonances vanish as lower order resonances. After giving a sharp estimate of the resonance domain, we

Symmetry and resonance in Hamiltonian systems

NARCIS (Netherlands)

Tuwankotta, J.M.; Verhulst, F.

1999-01-01

In this paper we study resonances in two degrees of freedom, autonomous, hamiltonian systems. Due to the presence of a symmetry condition on one of the degrees of freedom, we show that some of the resonances vanish as lower order resonances. After determining the size of the resonance domain, we

Magnetic resonance fingerprinting.

Science.gov (United States)

Ma, Dan; Gulani, Vikas; Seiberlich, Nicole; Liu, Kecheng; Sunshine, Jeffrey L; Duerk, Jeffrey L; Griswold, Mark A

2013-03-14

Magnetic resonance is an exceptionally powerful and versatile measurement technique. The basic structure of a magnetic resonance experiment has remained largely unchanged for almost 50 years, being mainly restricted to the qualitative probing of only a limited set of the properties that can in principle be accessed by this technique. Here we introduce an approach to data acquisition, post-processing and visualization--which we term 'magnetic resonance fingerprinting' (MRF)--that permits the simultaneous non-invasive quantification of multiple important properties of a material or tissue. MRF thus provides an alternative way to quantitatively detect and analyse complex changes that can represent physical alterations of a substance or early indicators of disease. MRF can also be used to identify the presence of a specific target material or tissue, which will increase the sensitivity, specificity and speed of a magnetic resonance study, and potentially lead to new diagnostic testing methodologies. When paired with an appropriate pattern-recognition algorithm, MRF inherently suppresses measurement errors and can thus improve measurement accuracy.

Resonant enhancement in leptogenesis

Science.gov (United States)

Dev, P. S. B.; Garny, M.; Klaric, J.; Millington, P.; Teresi, D.

2018-02-01

Vanilla leptogenesis within the type I seesaw framework requires the mass scale of the right-handed neutrinos to be above 109 GeV. This lower bound can be avoided if at least two of the sterile states are almost mass degenerate, which leads to an enhancement of the decay asymmetry. Leptogenesis models that can be tested in current and upcoming experiments often rely on this resonant enhancement, and a systematic and consistent description is therefore necessary for phenomenological applications. In this paper, we give an overview of different methods that have been used to study the saturation of the resonant enhancement when the mass difference becomes comparable to the characteristic width of the Majorana neutrinos. In this limit, coherent flavor transitions start to play a decisive role, and off-diagonal correlations in flavor space have to be taken into account. We compare various formalisms that have been used to describe the resonant regime and discuss under which circumstances the resonant enhancement can be captured by simplified expressions for the CP asymmetry. Finally, we briefly review some of the phenomenological aspects of resonant leptogenesis.

Advances in magnetic resonance 6

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 6 focuses on the theoretical and practical aspects of applying magnetic resonance methods to various problems in physical chemistry, emphasizing the different aspects of the exegesis of these problems. This book discusses the gas phase magnetic resonance of electronically excited molecules; techniques for observing excited electronic states; NMR studies in liquids at high pressure; and effect of pressure on self-diffusion in liquids. The nuclear magnetic resonance investigations of organic free radicals; measurement of proton coupling constants by NMR; an

Resonant characteristics and sensitivity dependency on the contact surface in QCM-micropillar-based system of coupled resonator sensors

International Nuclear Information System (INIS)

Kashan, M A M; Kalavally, V; Ramakrishnan, N; Lee, H W

2016-01-01

We report the characteristics and sensitivity dependence over the contact surface in coupled resonating sensors (CRSs) made of high aspect ratio resonant micropillars attached to a quartz crystal microbalance (QCM). Through experiments and simulation, we observed that when the pillars of resonant heights were placed in maximum displacement regions the resonance frequency of the QCM increased following the coupled resonance characteristics, as the pillar offered elastic loading to the QCM surface. However, the same pillars when placed in relatively lower displacement regions, in spite of their resonant dimension, offered inertial loading and resulted in a decrease in QCM resonance frequency, as the displacement amplitude was insufficient to couple the vibrations from the QCM to the pillars. Accordingly, we discovered that the coupled resonance characteristics not only depend on the resonant structure dimensions but also on the contact regions in the acoustic device. Further analysis revealed that acoustic pressure at the contact surface also influences the resonance frequency characteristics and sensitivity of the CRS. To demonstrate the significance of the present finding for sensing applications, humidity sensing is considered as the example measurand. When a sensing medium made of resonant SU-8 pillars was placed in a maximum displacement region on a QCM surface, the sensitivity increased by 14 times in comparison to a resonant sensing medium placed in a lower displacement region of a QCM surface. (paper)

Spin with two snakes and overlapping resonances

International Nuclear Information System (INIS)

Lee, S.Y.; Zhao, X.F.

1987-01-01

We study the effect of multiple spin depolarization resonances on the spin of the particles with two snakes. When two resonances are well separated, the polarization can be restored in passing through these resonances provided that the snake resonances are avoided. When two resonances are overlapping, the beam particles may be depolarized depending on the spacing between these two resonances. If the spacing between these two resonances is an odd number for two snakes, the beam particles may be depolarized depending on the strength of the resonance. When the spacing becomes an even number, the spin can tolerate a much larger resonance strength without depolarization. Numerical simulations can be shown to agree well with the analytic formula. However, the spin is susceptible to the combination of an intrinsic and an imperfection resonances even in the presence of the snakes. Numerical simulation indicates that the spin can be restored after the resonances provided that imperfection strength is less than 0.1 if intrinsic strength is fixed at 0.745

Electromagnetic resonance waves

International Nuclear Information System (INIS)

Villaba, J.M.; Manjon, F.J.; Guirao, A.; Andres, M.V.

1994-01-01

We describe in this paper a set of experiments designed to make qualitative and quantitative measurements on electromagnetic resonances of several simple systems. The experiments are designed for the undergraduate laboratory of Electricity and Magnetism in Physics. These experiments can help the students understanding the concept of resonance, which appears in different fields of Physics. (Author) 8 refs

Baryon Resonances

International Nuclear Information System (INIS)

Oset, E.; Sarkar, S.; Sun Baoxi; Vicente Vacas, M.J.; Ramos, A.; Gonzalez, P.; Vijande, J.; Martinez Torres, A.; Khemchandani, K.

2010-01-01

In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the Λ(1405) resonance, as well as the prediction of one 1/2 + baryon state around 1920 MeV which might have been seen in the γp→K + Λ reaction.

Introduction lecture to magnetic resonance

International Nuclear Information System (INIS)

Conard, J.

1980-01-01

This lecture deals with all that is common either to electron paramagnetic resonance (E.P.R.) or to nuclear magnetic resonance (N.M.R.). It will present, in an as elementary form as possible, the main concepts used in magnetic resonance emphasizing some aspects, specific for interface science. (orig./BHO)

Dihadronic and dileptonic resonances

International Nuclear Information System (INIS)

Gareev, F.A.; Barabanov, M.Yu.; Kazacha, G.S.

1997-01-01

Simple phenomenological rules are suggested for calculation of dihadron and dilepton resonance masses. A general interpretation is given for different exotic resonances in nuclear physics: Darmstadt-effect, dibaryon, dipion and other resonances. Information about the inner structure of e ± , proton, neutron, pions and so on can be obtained from the usual reactions of the type e + + e - =>γγ, e ± +γ=>e ± γ, e ± μ ± , e ± N... at low, intermediate and high energies using existing experimental devices

Transit time for resonant tunneling

International Nuclear Information System (INIS)

Garcia Calderon, G.; Rubio, A.

1990-09-01

This work considers properties of the partial widths in one dimensional elastic resonant tunneling in order to propose a transit-time τ tr = (h/2π)/Γ n T res ) where Γ n is the elastic width and T res the transmission coefficient at resonance energy. This time is interpreted as an average over the resonance energy width. It is shown that the tunneling current density integrated across a sharp resonance is inversely proportional to τ tr . This transit time may be much larger than the values predicted by other definitions. (author). 20 refs

Orbital resonances around black holes.

Science.gov (United States)

Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja

2015-02-27

We compute the length and time scales associated with resonant orbits around Kerr black holes for all orbital and spin parameters. Resonance-induced effects are potentially observable when the Event Horizon Telescope resolves the inner structure of Sgr A*, when space-based gravitational wave detectors record phase shifts in the waveform during the resonant passage of a compact object spiraling into the black hole, or in the frequencies of quasiperiodic oscillations for accreting black holes. The onset of geodesic chaos for non-Kerr spacetimes should occur at the resonance locations quantified here.

Properties of resonance wave functions.

Science.gov (United States)

More, R. M.; Gerjuoy, E.

1973-01-01

Construction and study of resonance wave functions corresponding to poles of the Green's function for several illustrative models of theoretical interest. Resonance wave functions obtained from the Siegert and Kapur-Peierls definitions of the resonance energies are compared. The comparison especially clarifies the meaning of the normalization constant of the resonance wave functions. It is shown that the wave functions may be considered renormalized in a sense analogous to that of quantum field theory. However, this renormalization is entirely automatic, and the theory has neither ad hoc procedures nor infinite quantities.

Advances in magnetic resonance 12

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 12, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains six chapters and begins with a discussion of diffusion and self-diffusion measurements by nuclear magnetic resonance. This is followed by separate chapters on spin-lattice relaxation time in hydrogen isotope mixtures; the principles of optical detection of nuclear spin alignment and nuclear quadropole resonance; and the spin-1 behavior, including the relaxation of the quasi-invariants of the motion of a system of pairs of dipolar coupled spin-1/2 nu

Far-wing light absorption induced by resonant or near-resonant collisions

International Nuclear Information System (INIS)

Cavalieri, S.; Celli, M.

1996-01-01

The authors have studied the absorption of light induced by a resonant or near-resonant collision between two atoms. The calculations have been performed by taking into account also the magnetic sublevels, which makes their theoretical predictions more applicable to realistic cases. Analytical expressions for the far-wing absorption cross-section have been obtained

Accidental degeneracy of resonances

International Nuclear Information System (INIS)

Hernandez, E.; Mondragon, A.; Jauregui, A.

2001-01-01

Full text: It will be shown that a degeneracy of resonances is associated with a second rank pole in the scattering matrix and a Jordan cycle of generalized eigenfunctions of the radial Schrodinger equation. The generalized Gamow-Jordan eigenfunctions are basis elements of an expansion in complex resonance energy eigenfunctions. In this orthonormal basis, the Hamiltonian is represented by a non-diagonal complex matrix with a Jordan block of rank two. Some general properties of the degeneracy of resonances will be exhibited and discussed in an explicit example of degeneracy of resonant states and double poles in the scattering matrix of a double barrier potential. The cross section, scattering wave functions and Jordan-Gamow eigenfunctions are computed at degeneracy and their properties as functions of the control parameters of the system are discussed. (Author)

Synchronous double primary cancers of the extrahepatic bile duct: A case report and literature review.

Science.gov (United States)

Nishi, Takeshi; Sato, Yoshitoshi; Hanaoka, Takuya; Takahashi, Takuya; Miura, Hiroshi; Takubo, Kenji

2018-01-01

Double cancers of the biliary tract system are rare. Most of these cancers are synchronous double cancers of the gall bladder and bile duct, associated with pancreaticobiliary maljunction (PBM). Synchronous double cancers of the extrahepatic bile duct without PBM are especially rare, and only 4 cases have been reported. A 78-year-old woman was admitted to our hospital for examination of hyperbilirubinemia and liver dysfunction. Contrast-enhanced abdominal computed tomography, Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography revealed 2 stenotic regions in the common bile duct: at its junction with the cystic duct and in the distal bile duct. No findings suggested PBM, such as a markedly long common channel. The diagnosis based on endoscopic brush cytology from both stricture portions was adenocarcinoma. The patient had a pylorus-preserving pancreaticoduodenectomy with regional lymph node resection. Macroscopically, there were 2 stenotic regions at the cystic duct junction and in the distal bile duct. Microscopically, the tumor at the junction of the cystic duct was a well-to-moderately differentiated adenocarcinoma. On the other hand, the tumor of the distal bile duct was a poorly differentiated adenocarcinoma. There was no evidence of communication between these 2 cancers. Double cancers of the extrahepatic bile duct without PBM are very rare. Therefore, an accurate diagnosis prior to surgery is necessary. Furthermore, this rare condition seems to be associated with a poor prognosis. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Complex Case of Cholestasis in a Patient with ABCB4 and ABCB11 Mutations

Directory of Open Access Journals (Sweden)

Mariana Ferreira Cardoso

2017-11-01

Full Text Available The low-phospholipid-associated cholelithiasis (LPAC syndrome is a form of symptomatic cholelithiasis occurring in young adults, characterized by recurrence of symptoms after cholecystectomy and presence of hepatolithiasis. The case refers to a healthy 39-year-old Caucasian male who presented with abdominal pain and jaundice. His blood tests showed conjugated hyperbilirubinemia and elevated liver enzymes (total bilirubin 6.65 mg/dL, γ-glutamyltransferase 699 IU/L and abdominal computed tomography revealed dilation of common bile duct and left intrahepatic ducts. Magnetic resonance cholangiopancreatography identified choledocholithiasis, retrieved by endoscopic retrograde cholangiopancreatography, after which there was a worsening of jaundice (total bilirubin 23 mg/dL, which persisted for several weeks, possibly due to ciprofloxacin toxicity. After an extensive workup including liver biopsy, the identification of two foci of hepatolithiasis on reevaluation abdominal ultrasound raised the hypothesis of LPAC syndrome and the patient was started on ursodeoxycholic acid, with remarkable improvement. Genetic testing identified the mutation c.1954A>G (p.Arg652Gly in ABCB4 gene (homozygous and c.1331T>C (p.Val444Ala in ABCB11 gene (heterozygous. In conclusion, we describe the unique case of an adult male with choledocholithiasis, hepatolithiasis, and persistent conjugated hyperbilirubinemia after retrieval of stones, fulfilling the criteria for LPAC syndrome and with possible superimposed drug-induced liver injury, in whom ABCB4 and ABCB11 mutations were found, both of which had not been previously described in association with LPAC.

Review on resonance cone fields

International Nuclear Information System (INIS)

Ohnuma, Toshiro.

1980-02-01

Resonance cone fields and lower hybrid heating are reviewed in this report. The resonance cone fields were reported by Fisher and Gould, and they proposed the use of the measurement of resonance cones and structure as a diagnostic tool to determine the plasma density and electron temperature in magnetoplasma. After the resonance cone, a wave-like disturbance persists. Ohnuma et al. have measured bending, reflection and ducting of resonance cones in detail. The thermal modes in inhomogeneous magnetoplasma were seen. The reflection of thermal mode near an electron plasma frequency layer and an insulating plate has been observed. The non-linear effects of resonance cones is reported. Monochromatic electron beam produces the noise of broad band whistler mode. Lower hybrid waves have been the subject of propagation from the edge of plasma to the lower hybrid layer. Linear lower hybrid waves were studied. The lower hybrid and ion acoustic waves radiated from a point source were observed. The parametric decay of finite-extent, cold electron plasma waves was studied. The lower hybrid cone radiated from a point source going along magnetic field lines was observed. Several experimental data on the lower hybrid heating in tokamak devices have been reported. The theories on resonance cones and lower hybrid waves are introduced in this report. (Kato, T.)

Resonant dynamics of gravitationally bound pair of binaries: the case of 1:1 resonance

Science.gov (United States)

Breiter, Slawomir; Vokrouhlický, David

2018-04-01

The work presents a study of the 1:1 resonance case in a hierarchical quadruple stellar system of the 2+2 type. The resonance appears if orbital periods of both binaries are approximately equal. It is assumed that both periods are significantly shorter than the period of principal orbit of one binary with respect to the other. In these circumstances, the problem can be treated as three independent Kepler problems perturbed by mutual gravitational interactions. By means of canonical perturbation methods, the planar problem is reduced to a secular system with 1 degree of freedom involving a resonance angle (the difference of mean longitudes of the binaries) and its conjugate momentum (involving the ratio of orbital period in one binary to the period of principal orbit). The resonant model is supplemented with short periodic perturbations expressions, and verified by the comparison with numerical integration of the original equations of motion. Estimates of the binaries periods variations indicate that the effect is rather weak, but possibly detectible if it occurs in a moderately compact system. However, the analysis of resonance capture scenarios implies that the 1:1 resonance should be exceptional amongst the 2+2 quadruples.

Optical Microspherical Resonators for Biomedical Sensing

Directory of Open Access Journals (Sweden)

Giancarlo C. Righini

2011-01-01

Full Text Available Optical resonators play an ubiquitous role in modern optics. A particular class of optical resonators is constituted by spherical dielectric structures, where optical rays are total internal reflected. Due to minimal reflection losses and to potentially very low material absorption, these guided modes, known as whispering gallery modes, can confer the resonator an exceptionally high quality factor Q, leading to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. These attractive characteristics make these miniaturized optical resonators especially suited as laser cavities and resonant filters, but also as very sensitive sensors. First, a brief analysis is presented of the characteristics of microspherical resonators, of their fabrication methods, and of the light coupling techniques. Then, we attempt to overview some of the recent advances in the development of microspherical biosensors, underlining a number of important applications in the biomedical field.

Excitation of Nucleon Resonances

International Nuclear Information System (INIS)

Burkert, Volker D.

2001-01-01

I discuss developments in the area of nucleon resonance excitation, both necessary and feasible, that would put our understanding of nucleon structure in the regime of strong QCD on a qualitatively new level. They involve the collection of high quality data in various channels, a more rigorous approach in the search for ''missing'' resonances, an effort to compute some critical quantities in nucleon resonance excitations from first principles, i.e. QCD, and a proposal focused to obtain an understanding of a fundamental quantity in nucleon structure

Doubly resonant multiphoton ionization

International Nuclear Information System (INIS)

Crance, M.

1978-01-01

A particular case of doubly resonant multiphoton ionization is theoretically investigated. More precisely, two levels quasi-resonant with two successive harmonics of the field frequency are considered. The method used is based on the effective operator formalism first introduced for this problem by Armstrong, Beers and Feneuille. The main result is to show the possibility of observing large interference effects on the width of the resonances. Moreover this treatment allows us to make more precise the connection between effective operator formalism and standard perturbation theory

Extraordinary acoustic transmission mediated by Helmholtz resonators

Directory of Open Access Journals (Sweden)

Vijay Koju

2014-07-01

Full Text Available We demonstrate perfect transmission of sound through a rigid barrier embedded with Helmholtz resonators. The resonators are confined within a waveguide and they are oriented such that one neck protrudes onto each side of the barrier. Perfect sound transmission occurs even though the open area of the necks is less than 3% of the barrier area. Maximum transmission occurs at the resonant frequency of the Helmholtz resonator. Because the dimensions of the Helmholtz resonators are much smaller than the resonant wavelength, the transmission is independent of the direction of sound on the barrier and of the relative placement of the necks. Further, we show that the transmitted sound experiences a continuous phase transition of π radians as a function of frequency through resonance. In simulations of adjacent resonators with slightly offset resonance frequencies, the phase difference leads to destructive interference. By expanding the simulation to a linear array of tuned Helmholtz resonators we show that it is possible to create an acoustic lens. The ability of Helmholtz resonator arrays to manipulate the phase of a plane acoustic wave enables a new class of sonic beam-forming devices analogous to diffractive optics.

Resonances and anti-resonances in the material parameters of 2-D dielectric ENG, MNG, and DNG materials

DEFF Research Database (Denmark)

Wu, Yunqiu; Arslanagic, Samel

The resonant/anti-resonant behavior of parameters extracted by the S-parameter method for two-dimensional epsilon-, mu- and double-negative (ENG, MNG, DNG) materials is investigated. The unit cells consist of infinite dielectric cylinders supporting electric dipole, magnetic dipole, or both....... It is shown that the extraction procedure yields one resonant material parameter, and one anti-resonant material parameter in MNG and ENG configurations. However, both parameters display an over-all resonant response in DNG configurations where electric and magnetic dipole modes are excited simultaneously....

Proton magnetic resonance spectroscopy and perfusion magnetic resonance imaging in the evaluation of musculoskeletal tumors

International Nuclear Information System (INIS)

Costa, Flavia Martins; Setti, Marcela; Vianna, Evandro Miguelote; Domingues, Romulo Cortes; Meohas, Walter; Rezende, Jose Francisco; Gasparetto, Emerson Leandro

2009-01-01

Objective: To assess the role of proton magnetic resonance spectroscopy and dynamic contrast-enhanced magnetic resonance imaging in the differentiation between malignant and benign musculoskeletal tumors. Materials And Methods: Fifty-five patients with musculoskeletal tumors (27 malignant and 28 benign) were studied. The examinations were performed in a 1.5 T magnetic resonance scanner with standard protocol, and single voxel proton magnetic resonance spectroscopy with 135 msec echo time. The dynamic contrast study was performed using T1-weighted gradient-echo sequence after intravenous gadolinium injection. Time signal intensity curves and slope values were calculated. The statistical analysis was performed with the Levene's test, followed by a Student's t-test, besides the Pearson's chi-squared and Fischer's exact tests. Results: Proton magnetic resonance spectroscopy sensitivity, specificity and accuracy were, respectively, 87.5%, 92.3% and 90.9% (p < 0.0001). Statistically significant difference was observed in the slope (%/min) between benign (mean, 27.5%/min) and malignant (mean, 110.9%/min) lesions (p < 0.0001). Conclusion: The time-intensity curve and slope values using dynamic-enhanced perfusion magnetic resonance imaging in association with the presence of choline peak demonstrated by single voxel magnetic resonance spectroscopy study are useful in the differentiation between malignant and benign musculoskeletal tumors. (author)

Surgical versus endoscopic treatment of bile duct stones

DEFF Research Database (Denmark)

Martin, D J; Vernon, D R; Toouli, J

2006-01-01

10% to 18% of patients undergoing cholecystectomy for gallstones have common bile duct (CBD) stones. Treatment options for these stones include pre- or post-operative endoscopic retrograde cholangiopancreatography (ERCP) or open or laparoscopic surgery.......10% to 18% of patients undergoing cholecystectomy for gallstones have common bile duct (CBD) stones. Treatment options for these stones include pre- or post-operative endoscopic retrograde cholangiopancreatography (ERCP) or open or laparoscopic surgery....

Algorithm of resonance orders for the objects

Science.gov (United States)

Zhang, YongGang; Zhang, JianXue

2018-03-01

In mechanical engineering, the object resonance phenomena often occur when the external incident wave frequency is close to object of the natural frequency. Object resonance phenomena get the maximum value when the external incident frequency is equal to object the natural frequency. Experiments found that resonance intension of the object is changed, different objects resonance phenomena present different characteristics of ladders. Based on object orders resonance characteristics, the calculation method of object orders resonance is put forward in the paper, and the application for the light and sound waves on the seven order resonance characteristics by people feel, the result error is less than 1%.Visible in this paper, the method has high accuracy and usability. The calculation method reveals that some object resonance occur present order characteristic only four types, namely the first-orders resonance characteristics, third-orders characteristics, five orders characteristic, and seven orders characteristic.

Effect of endoscopic transpapillary biliary drainage with/without endoscopic sphincterotomy on post-endoscopic retrograde cholangiopancreatography pancreatitis in patients with biliary stricture (E-BEST): a protocol for a multicentre randomised controlled trial.

Science.gov (United States)

Kato, Shin; Kuwatani, Masaki; Sugiura, Ryo; Sano, Itsuki; Kawakubo, Kazumichi; Ono, Kota; Sakamoto, Naoya

2017-08-11

The effect of endoscopic sphincterotomy prior to endoscopic biliary stenting to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis remains to be fully elucidated. The aim of this study is to prospectively evaluate the non-inferiority of non-endoscopic sphincterotomy prior to stenting for naïve major duodenal papilla compared with endoscopic sphincterotomy prior to stenting in patients with biliary stricture. We designed a multicentre randomised controlled trial, for which we will recruit 370 patients with biliary stricture requiring endoscopic biliary stenting from 26 high-volume institutions in Japan. Patients will be randomly allocated to the endoscopic sphincterotomy group or the non-endoscopic sphincterotomy group. The main outcome measure is the incidence of pancreatitis within 2 days of initial transpapillary biliary drainage. Data will be analysed on completion of the study. We will calculate the 95% confidence intervals (CIs) of the incidence of pancreatitis in each group and analyse weather the difference in both groups with 95% CIs is within the non-inferiority margin (6%) using the Wald method. This study has been approved by the institutional review board of Hokkaido University Hospital (IRB: 016-0181). Results will be submitted for presentation at an international medical conference and published in a peer-reviewed journal. The University Hospital Medical Information Network ID: UMIN000025727 Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Electrothermally Tunable Arch Resonator

KAUST Repository

Hajjaj, Amal Z.

2017-03-18

This paper demonstrates experimentally, theoretically, and numerically a wide-range tunability of electrothermally actuated microelectromechanical arch beams. The beams are made of silicon and are intentionally fabricated with some curvature as in-plane shallow arches. An electrothermal voltage is applied between the anchors of the beam generating a current that controls the axial stress caused by thermal expansion. When the electrothermal voltage increases, the compressive stress increases inside the arch beam. This leads to an increase in its curvature, thereby increasing its resonance frequencies. We show here that the first resonance frequency can increase monotonically up to twice its initial value. We show also that after some electrothermal voltage load, the third resonance frequency starts to become more sensitive to the axial thermal stress, while the first resonance frequency becomes less sensitive. These results can be used as guidelines to utilize arches as wide-range tunable resonators. Analytical results based on the nonlinear Euler Bernoulli beam theory are generated and compared with the experimental data and the results of a multi-physics finite-element model. A good agreement is found among all the results. [2016-0291

Resonance phenomenon in classical cepheids

International Nuclear Information System (INIS)

Takeuti, Mine; Aikawa, Toshiki

1981-01-01

To investigate resonance phenomenon in classical cepheids, the non-linear radial oscillation of stars is studied based on the assumption that the non-adiabatic perturbation is expressed in terms of van der Pol's type damping. Two- and three-wave resonance in this system is applied to classical cepheids to describe their bump and double-mode behavior. The phase of bump and the depression of amplitude are explained for bump cepheids. The double-periodicity is shown by the enhancement of the third overtone in three-wave resonance. Non-linear effect on resonant period is also discussed briefly. (author)

Resonance contribution to electromagnetic structure functions

International Nuclear Information System (INIS)

Bowling, A.L. Jr.

1974-01-01

The part of the pion and proton electromagnetic structure functions due to direct channel resonances in the virtual Compton amplitude is discussed. After a phenomenological discussion, based on the work of Bloom and Gilman, of resonance production in inelastic electroproduction, the single resonance contribution to the pion and proton structure functions is expressed in terms of transition form factors. Froissart-Gribov representations of the Compton amplitude partial waves are presented and are used to specify the spin dependence of the transition form factors. The dependence of the form factors on momentum transfer and resonance mass is assumed on the basis of the behavior of exclusive resonance electroproduction. The single resonance contributions are summed in the Bjorken limit, and the result exhibits Bjorken scaling. Transverse photons are found to dominate in the Bjorken limit, and the threshold behavior of the resonant part of the structure functions is related to the asymptotic behavior of exclusive form factors at large momentum transfer. The resonant parts of the annihilation structure functions are not in general given by simple analytic continuation in the scaling vari []ble ω' of the electroproduction structure functions. (Diss. Abstr. Int., B)

A resonant dc-dc power converter assembly

OpenAIRE

Madsen, Mickey Pierre

2015-01-01

The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the second resonant DC-DC power converter are configured for magnetically coupling the first and second resonant DC-DC power converters to each other to forcing substantially 180 degrees phase shift, or fo...

Electron Paramagnetic Resonance Spectroscopy

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 11. Electron Paramagnetic Resonance Spectroscopy: Biological Applications. B G Hegde. General Article Volume 20 Issue 11 November 2015 pp 1017-1032. Fulltext. Click here to view fulltext PDF. Permanent link:

Giant multipole resonances: an experimental review

International Nuclear Information System (INIS)

Bertrand, F.E.

1979-01-01

During the past several years experimental evidence has been published for the existance of nondipole giant resonances. These giant multipole resonances, the so-called new giant resonances were first observed through inelastic hadron and electron scattering and such measurements have continued to provide most of the information in this field. A summary is provided of the experimental evidence for these new resonances. The discussion deals only with results from inelastic scattering and only with the electric multipoles. Emphasis is placed on the recent observations of the giant monopole resonance. Results from recent heavy-ion and pion inelastic scattering are discussed. 38 references

Advanced resonance self-shielding method for gray resonance treatment in lattice physics code GALAXY

International Nuclear Information System (INIS)

Koike, Hiroki; Yamaji, Kazuya; Kirimura, Kazuki; Sato, Daisuke; Matsumoto, Hideki; Yamamoto, Akio

2012-01-01

A new resonance self-shielding method based on the equivalence theory is developed for general application to the lattice physics calculations. The present scope includes commercial light water reactor (LWR) design applications which require both calculation accuracy and calculation speed. In order to develop the new method, all the calculation processes from cross-section library preparation to effective cross-section generation are reviewed and reframed by adopting the current enhanced methodologies for lattice calculations. The new method is composed of the following four key methods: (1) cross-section library generation method with a polynomial hyperbolic tangent formulation, (2) resonance self-shielding method based on the multi-term rational approximation for general lattice geometry and gray resonance absorbers, (3) spatially dependent gray resonance self-shielding method for generation of intra-pellet power profile and (4) integrated reaction rate preservation method between the multi-group and the ultra-fine-group calculations. From the various verifications and validations, applicability of the present resonance treatment is totally confirmed. As a result, the new resonance self-shielding method is established, not only by extension of a past concentrated effort in the reactor physics research field, but also by unification of newly developed unique and challenging techniques for practical application to the lattice physics calculations. (author)

Thermally actuated resonant silicon crystal nanobalances

Science.gov (United States)

Hajjam, Arash

As the potential emerging technology for next generation integrated resonant sensors and frequency references as well as electronic filters, micro-electro-mechanical resonators have attracted a lot of attention over the past decade. As a result, a wide variety of high frequency micro/nanoscale electromechanical resonators have recently been presented. MEMS resonators, as low-cost highly integrated and ultra-sensitive mass sensors, can potentially provide new opportunities and unprecedented capabilities in the area of mass sensing. Such devices can provide orders of magnitude higher mass sensitivity and resolution compared to Film Bulk Acoustic resonators (FBAR) or the conventional quartz and Surface Acoustic Wave (SAW) resonators due to their much smaller sizes and can be batch-fabricated and utilized in highly integrated large arrays at a very low cost. In this research, comprehensive experimental studies on the performance and durability of thermally actuated micromechanical resonant sensors with frequencies up to tens of MHz have been performed. The suitability and robustness of the devices have been demonstrated for mass sensing applications related to air-borne particles and organic gases. In addition, due to the internal thermo-electro-mechanical interactions, the active resonators can turn some of the consumed electronic power back into the mechanical structure and compensate for the mechanical losses. Therefore, such resonators can provide self-sustained-oscillation without the need for any electronic circuitry. This unique property has been deployed to demonstrate a prototype self-sustained sensor for air-borne particle monitoring. I have managed to overcome one of the obstacles for MEMS resonators, which is their relatively poor temperature stability. This is a major drawback when compared with the conventional quartz crystals. A significant decrease of the large negative TCF for the resonators has been attained by doping the devices with a high

Formation and coupling of band gaps in a locally resonant elastic system comprising a string with attached resonators

International Nuclear Information System (INIS)

Xiao Yong; Mace, Brian R.; Wen Jihong; Wen Xisen

2011-01-01

A uniform string with periodically attached spring-mass resonators represents a simple locally resonant continuous elastic system whose band gap mechanisms are basic to more general and complicated problems. In this Letter, analytical models with explicit formulations are provided to understand the band gap mechanisms of such a system. Some interesting phenomena are demonstrated and discussed, such as asymmetric/symmetric attenuation behavior within a resonance gap, and the realization of a super-wide gap due to exact coupling between Bragg and resonance gaps. In addition, some approximate formulas for the evaluation of low frequency resonance gaps are derived using an approach different from existing investigations. - Research highlights: → We examine band gaps in a special one-dimensional locally resonant system. → Bragg and resonance gaps co-exist. → Explicit formulas for locating band edges are derived. → Exact physical models are used to clarify the band gap formation mechanisms. → Coupling between Bragg and resonance gaps leads to a super-wide gap.

The combined resonance tunneling and semi-resonance level in low energy D-D reaction

International Nuclear Information System (INIS)

Li Xingzhong; Jin Dezhe; Chang Lee

1993-01-01

When nuclear potential wells are connected by an atomic potential well, a new kind of tunneling may happen even if there is no virtual energy level in nuclear potential wells. The necessary condition for this combined resonance tunneling is the resonance in the atomic potential well. Thus, the nuclear reaction may be affected by the action in atomic scale in terms of combined resonance tunneling. The nuclear spectrum data support this idea. (author)

Sensing performance analysis on Fano resonance of metallic double-baffle contained MDM waveguide coupled ring resonator

Science.gov (United States)

Chen, Ying; Luo, Pei; Liu, Xiaofei; Di, Yuanjian; Han, Shuaitao; Cui, Xingning; He, Lei

2018-05-01

Based on the transmission property and the photon localization characteristic of the surface plasmonic sub-wavelength structure, a metallic double-baffle contained metal-dielectric-metal (MDM) waveguide coupled ring resonator is proposed. Like the electromagnetically induced transparency (EIT), the Fano resonance can be achieved by the interference between the metallic double-baffle resonator and the ring resonator. Based on the coupled mode theory, the transmission property is analyzed. Through the numerical simulation by the finite element method (FEM), the quantitative analysis on the influences of the radius R of the ring and the coupling distance g between the metallic double-baffle resonator and the ring resonator for the figure of merit (FOM) is performed. And after the structure parameter optimization, the sensing performance of the waveguide structure is discussed. The simulation results show that the FOM value of the optimized structure can attain to 5.74 ×104 and the sensitivity of resonance wavelength with refractive index drift is about 825 nm/RIU. The range of the detected refractive index is suitable for all gases. The waveguide structure can provide effective theoretical references for the design of integrated plasmonic devices.

Entanglement Evolution of Jaynes-Cummings Model in Resonance Case and Non-resonance Case

Science.gov (United States)

Cheng, Jing; Chen, Xi; Shan, Chuan-Jia

2018-03-01

We investigate the entanglement evolution of a two-level atom and a quantized single model electromagnetic filed in the resonance and non-resonance cases. The effects of the initial state, detuning degree, photon number on the entanglement are shown in detail. The results show that the atom-cavity entanglement state appears with periodicity. The increasing of the photon number can make the period of quantum entanglement be shorter. In the non-resonant case, if we choose the suitable initial state the entanglement of atom-cavity can be 1.0

Electrically Tunable Plasmonic Resonances with Graphene

DEFF Research Database (Denmark)

Emani, Naresh K.; Chung, Ting-Fung; Ni, Xingjie

2012-01-01

Real time switching of a plasmonic resonance may find numerous applications in subwavelength optoelectronics, spectroscopy and sensing. We take advantage of electrically tunable interband transitions in graphene to control the strength of the plasmonic resonance.......Real time switching of a plasmonic resonance may find numerous applications in subwavelength optoelectronics, spectroscopy and sensing. We take advantage of electrically tunable interband transitions in graphene to control the strength of the plasmonic resonance....

Resonance and Fractal Geometry

NARCIS (Netherlands)

Broer, Henk W.

The phenomenon of resonance will be dealt with from the viewpoint of dynamical systems depending on parameters and their bifurcations. Resonance phenomena are associated to open subsets in the parameter space, while their complement corresponds to quasi-periodicity and chaos. The latter phenomena

Fourier transform nuclear magnetic resonance

International Nuclear Information System (INIS)

Geick, R.

1981-01-01

This review starts with the basic principles of resonance phenomena in physical systems. Especially, the connection is shown between the properties of these systems and Fourier transforms. Next, we discuss the principles of nuclear magnetic resonance. Starting from the general properties of physical systems showing resonance phenomena and from the special properties of nuclear spin systems, the main part of this paper reviews pulse and Fourier methods in nuclear magnetic resonance. Among pulse methods, an introduction will be given to spin echoes, and, apart from the principle of Fourier transform nuclear magnetic resonance, an introduction to the technical problems of this method, e.g. resolution in the frequency domain, aliasing, phase and intensity errors, stationary state of the spin systems for repetitive measurements, proton decoupling, and application of Fourier methods to systems in a nonequilibrium state. The last section is devoted to special applications of Fourier methods and recent developments, e.g. measurement of relaxation times, solvent peak suppression, 'rapid scan'-method, methods for suppressing the effects of dipolar coupling in solids, two-dimensional Fourier transform nuclear magnetic resonance, and spin mapping or zeugmatography. (author)

Double Fano resonances in plasmon coupling nanorods

International Nuclear Information System (INIS)

Liu, Fei; Jin, Jie

2015-01-01

Fano resonances are investigated in nanorods with symmetric lengths and side-by-side assembly. Single Fano resonance can be obtained by a nanorod dimer, and double Fano resonances are shown in nanorod trimers with side-by-side assembly. With transverse plasmon excitation, Fano resonances are caused by the destructive interference between a bright superradiant mode and dark subradiant modes. The bright mode originates from the electric plasmon resonance, and the dark modes originate from the magnetic resonances induced by near-field inter-rod coupling. Double Fano resonances result from double dark modes at different wavelengths, which are induced and tuned by the asymmetric gaps between the adjacent nanorods. Fano resonances show a high figure of merit and large light extinction in the periodic array of assembled nanorods, which can potentially be used in multiwavelength sensing in the visible and near-infrared regions. (paper)

Integrated unaligned resonant modulator tuning

Energy Technology Data Exchange (ETDEWEB)

Zortman, William A.; Lentine, Anthony L.

2017-10-03

Methods and systems for tuning a resonant modulator are disclosed. One method includes receiving a carrier signal modulated by the resonant modulator with a stream of data having an approximately equal number of high and low bits, determining an average power of the modulated carrier signal, comparing the average power to a predetermined threshold, and operating a tuning device coupled to the resonant modulator based on the comparison of the average power and the predetermined threshold. One system includes an input structure, a plurality of processing elements, and a digital control element. The input structure is configured to receive, from the resonant modulator, a modulated carrier signal. The plurality of processing elements are configured to determine an average power of the modulated carrier signal. The digital control element is configured to operate a tuning device coupled to the resonant modulator based on the average power of the modulated carrier signal.

Resonant diphoton phenomenology simplified

International Nuclear Information System (INIS)

Panico, Giuliano; Vecchi, Luca; Wulzer, Andrea

2016-01-01

A framework is proposed to describe resonant diphoton phenomenology at hadron colliders in full generality. It can be employed for a comprehensive model-independent interpretation of the experimental data. Within the general framework, few benchmark scenarios are defined as representative of the various phenomenological options and/or of motivated new physics scenarios. Their usage is illustrated by performing a characterization of the 750 GeV excess, based on a recast of available experimental results. We also perform an assessment of which properties of the resonance could be inferred, after discovery, by a careful experimental study of the diphoton distributions. These include the spin J of the new particle and its dominant production mode. Partial information on its CP-parity can also be obtained, but only for J≥2. The complete determination of the resonance CP properties requires studying the pattern of the initial state radiation that accompanies the resonant diphoton production.

Lattices of dielectric resonators

CERN Document Server

Trubin, Alexander

2016-01-01

This book provides the analytical theory of complex systems composed of a large number of high-Q dielectric resonators. Spherical and cylindrical dielectric resonators with inferior and also whispering gallery oscillations allocated in various lattices are considered. A new approach to S-matrix parameter calculations based on perturbation theory of Maxwell equations, developed for a number of high-Q dielectric bodies, is introduced. All physical relationships are obtained in analytical form and are suitable for further computations. Essential attention is given to a new unified formalism of the description of scattering processes. The general scattering task for coupled eigen oscillations of the whole system of dielectric resonators is described. The equations for the  expansion coefficients are explained in an applicable way. The temporal Green functions for the dielectric resonator are presented. The scattering process of short pulses in dielectric filter structures, dielectric antennas  and lattices of d...

Transmission Line Resonator Segmented with Series Capacitors

DEFF Research Database (Denmark)

Zhurbenko, Vitaliy; Boer, Vincent; Petersen, Esben Thade

2016-01-01

Transmission line resonators are often used as coils in high field MRI. Due to distributed nature of such resonators, coils based on them produce inhomogeneous field. This work investigates application of series capacitors to improve field homogeneity along the resonator. The equations for optimal...... values of evenly distributed capacitors are presented. The performances of the segmented resonator and a regular transmission line resonator are compared....

Resonance capture and Saturn's rings

International Nuclear Information System (INIS)

Patterson, C.W.

1986-05-01

We have assigned the resonances apparently responsible for the stabilization of the Saturn's shepherd satellites and for the substructure seen in the F-ring and the ringlets in the C-ring. We show that Saturn's narrow ringlets have a substructure determined by three-body resonances with Saturn's ringmoons and the sun. We believe such resonances have important implications to satellite formation. 17 refs., 1 fig., 1 tab

Fano resonances from gradient-index metamaterials.

Science.gov (United States)

Xu, Yadong; Li, Sucheng; Hou, Bo; Chen, Huanyang

2016-01-27

Fano resonances - resonant scattering features with a characteristic asymmetric profile - have generated much interest, due to their extensive and valuable applications in chemical or biological sensors, new types of optical switches, lasers and nonlinear optics. They have been observed in a wide variety of resonant optical systems, including photonic crystals, metamaterials, metallic gratings and nanostructures. In this work, a waveguide structure is designed by employing gradient-index metamaterials, supporting strong Fano resonances with extremely sharp spectra. As the changes in the transmission spectrum originate from the interaction of guided modes from different channels, instead of resonance structures or metamolecules, the Fano resonances can be observed for both transverse electric and transverse magnetic polarizations. These findings are verified by fine agreement with analytical calculations and experimental results at microwave, as well as simulated results at near infrared frequencies.

Cardiac magnetic resonance imaging

African Journals Online (AJOL)

2011-03-06

Mar 6, 2011 ... Cardiac magnetic resonance imaging. Cardiovascular magnetic resonance imaging is becoming a routine diagnostic technique. BRUCE s sPOTTiswOOdE, PhD. MRC/UCT Medical Imaging Research Unit, University of Cape Town, and Division of Radiology, Stellenbosch University. Bruce Spottiswoode ...

Magnetic resonance for wireless power transfer

OpenAIRE

Hui, SYR

2016-01-01

Magnetic resonance has been a cornerstone of nonradiative wireless power transfer (WPT) since the late 19th century. However, some researchers have the misconception that magnetic resonance for WPT was developed recently. This article traces some early work of Tesla and other researchers related to the use of magnetic resonance in WPT. Included are some examples of magnetic resonance-based WPT projects conducted by researchers in the biomedical and power electronics communities over the last ...

Low-profile wireless passive resonators for sensing

Energy Technology Data Exchange (ETDEWEB)

Gong, Xun; An, Linan

2017-04-04

A resonator for sensing a physical or an environmental parameter includes a support having a top surface that provides a ground plane, and a polymer-derived ceramic (PDC) element positioned on the top surface including a PDC layer, and a metal patch on the PDC layer. The metal patch is electrically isolated from all surrounding structure, and the resonator has a resonant frequency that changes as a function of the physical or environmental parameter. A system for wirelessly sensing a physical or environmental parameter includes at least one resonator and a wireless RF reader located remotely from the resonator for transmitting a wide-band RF interrogation signal that excites the resonator. The wireless RF reader detects a sensing signal retransmitted by the resonator and includes a processor for determining the physical or environmental parameter at the location of the resonator from the sensing signal.