Endoscopic retrograde cholangiopancreatography-related adverse events in Korea: A nationwide assessment.

BACKGROUND: Although endoscopic retrograde cholangiopancreatography (ERCP) is a pivotal procedure for the diagnosis and treatment of a variety of pancreatobiliary diseases, it has been known that the risk of procedure-related adverse events (AEs) is significant. OBJECTIVE: We conducted this nationwide cohort study since there have been few reports on the real-world data regarding ERCP-related AEs. METHODS: Patients who underwent ERCP were identified between 2012 and 2015 using Health Insurance Review and Assessment database generated by the Korea government. Incidence, annual trends, demographics, characteristics according to the types of procedures, and the risk factors of AEs were assessed. RESULTS: A total of 114,757 patients with male gender of 54.2% and the mean age of 65.0 ± 15.2 years were included. The most common indication was choledocholithiasis (49.4%) and the second malignant biliary obstruction (22.8%). Biliary drainage (33.9%) was the most commonly performed procedure, followed by endoscopic sphincterotomy (27.4%), and stone removal (22.0%). The overall incidence of ERCP-related AEs was 4.7% consisting of post-ERCP pancreatitis (PEP; 4.6%), perforation (0.06%), and hemorrhage (0.02%), which gradually increased from 2012 to 2015. According to the type of procedures, ERCP-related AEs developed the most commonly after pancreatic stent insertion (11.4%), followed by diagnostic ERCP (5.9%) and endoscopic sphincterotomy (5.7%). Younger age and diagnostic ERCP turned out to be independent risk factors of PEP. CONCLUSIONS: ERCP-related AEs developed the most commonly after pancreatic stent insertion, diagnostic ERCP and endoscopic sphincterotomy. Special caution should be used for young patients receiving diagnostic ERCP due to increased risk of PEP.

Radiologic Assessment for Endoscopic US-guided Biliary Drainage.

Endoscopic US-guided biliary drainage (BD) is performed for various types of biliary obstruction and is mainly indicated for unsuccessful conventional transpapillary endoscopic retrograde cholangiodrainage. In endoscopic US BD, an extra-anatomic drainage route between the gastrointestinal (GI) tract and the biliary system is created with a covered metallic stent or plastic stent. Procedural types of endoscopic US BD include hepaticogastrostomy, hepaticojejunostomy (after gastrectomy), choledochoduodenostomy, hepaticoduodenostomy, and endoscopic US-guided gallbladder drainage. The technical and clinical success rates of endoscopic US BD are reported to be 94%-97% and 88%-100%, respectively. CT is crucial both in preprocedural assessment and postprocedural monitoring. CT is used to determine the indications for endoscopic US BD, which include the type of biliary obstruction, collateral vessels in the puncture route, ascites, the volume of the liver segment, the distribution of an intrahepatic tumor, and GI tract patency. After endoscopic US BD, common subclinical findings are a small amount of intraperitoneal gas, localized edematous change in the GI tract, a notch in the placed stent, and localized biliary dilatation caused by stent placement. Stent malfunction after endoscopic US BD is caused by impaction of debris and/or food, stent migration into the GI tract, or tumor overgrowth and/or hyperplasia. Complications that can occur include internal stent migration, intraperitoneal biloma, arterial bleeding or pseudoaneurysm, perforation of the GI tract, and portobiliary fistula. The incidence of clinical endoscopic US BD-related complications is 11%-23%. ©RSNA, 2020.

Prospective Assessment of Ultrasound Shear Wave Elastography for Discriminating Biliary Atresia from other Causes of Neonatal Cholestasis.

OBJECTIVE: To prospectively assess the diagnostic performance of ultrasound shear wave elastography (SWE) and hepatobiliary laboratory biomarkers for discriminating biliary atresia from other causes of neonatal cholestasis. STUDY DESIGN: Forty-one patients <3 months of age with neonatal cholestasis (direct bilirubin >2 mg/dL) and possible biliary atresia were prospectively enrolled. Both 2-dimensional (2D) and point ultrasound SWE were performed prior to knowing the final diagnosis. Median 2D (8) and point (10) shear wave speed measurements were calculated for each subject and used for analyses. The Mann-Whitney U test was used to compare shear wave speed and laboratory measurements between patients with and without biliary atresia. Receiver operating characteristic curve analyses and multivariable logistic regression were used to evaluate diagnostic performance. RESULTS: Thirteen subjects (31.7%) were diagnosed with biliary atresia, and 28 subjects (68.3%) were diagnosed with other causes of neonatal cholestasis. Median age at the time of ultrasound SWE was 37 days. Median 2D (2.08 vs 1.49 m/s, P = .0001) and point (1.95 vs 1.21 m/s, P = .0014) ultrasound SWE measurements were significantly different between subjects with and without biliary atresia. Using a cut-off value of >1.84 m/s, 2D ultrasound SWE had a sensitivity = 92.3%, specificity = 78.6%, and area under the receiver operating characteristic curve (AuROC) of 0.89 (P < .0001). Using a cut-off value of >320 (U/L), gamma-glutamyl transferase (GGT) had a sensitivity = 100.0%, specificity = 77.8%, and AuROC of 0.85 (P < .0001). Multivariable logistic regression demonstrated an AuROC of 0.93 (P < .0001), with 2 significant covariates (2D ultrasound SWE [OR = 23.06, P = .01]; GGT [OR = 1.003, P = .036]). CONCLUSIONS: Ultrasound SWE and GGT can help discriminate biliary atresia from other causes of neonatal cholestasis.

Clinical Assessment of Differential Diagnostic Methods in Infants with Cholestasis due to Biliary Atresia or Non-Biliary Atresia.

The different methods in differentiating biliary atresia (BA) from non-BA-related cholestasis were evaluated in order to provide a practical basis for a rapid, early and accurate differential diagnosis of the diseases. 396 infants with cholestatic jaundice were studied prospectively during the period of May 2007 to June 2011. The liver function in all subjects was tested. All cases underwent abdominal ultrasonography and duodenal fluid examination. Most cases were subjected to hepatobiliary scintigraphy, magnetic resonance cholangiopancreatography (MRCP) and a percutaneous liver biopsy. The diagnosis of BA was finally made by cholangiography or histopathologic examination. The accuracy, sensitivity, specificity and predictive values of these various methods were compared. 178 patients (108 males and 70 females with a mean age of 58±30 days) were diagnosed as having BA. 218 patients (136 males and 82 females with a mean age of 61 ±24 days) were diagnosed as having non-BA etiologies of cholestasis jaundice during the follow-up period in which jaundice faded after treatment with medical therapy. For diagnosis of BA, clinical evaluation, hepatomegaly, stool color, serum gamma-glutamyltranspeptidase (GGT), duodenal juice color, bile acid in duodenal juice, ultrasonography (gallbladder), ultrasonography (griangular cord or strip-apparent hyperechoic foci), hepatobiliary scintigraphy, MRCP, liver biopsy had an accuracy of 76.0%, 51.8%, 84.3%, 70.0%, 92.4%, 98.0%, 90.4%, 67.2%, 85.3%, 83.2% and 96.6%, a sensitivity of 83.1%, 87.6%, 96.1%, 73.7%, 90.4%, 100%, 92.7%, 27.5%, 100%, 89.0% and 97.4%, a specificity of 70.2%, 77.5%, 74.8%, 67.0%, 94.0%, 96.3%, 88.5%, 99.5%, 73.3%, 75.4% and 94.3%, a positive predictive value of 69.0%, 72.6%, 75.7%, 64.6%, 92.5%, 95.7%, 86.8%, 98.0%, 75.4%, 82.6% and 98.0%, and a negative predictive value of 83.6%, 8.5%, 95.9%, 75.7%, 92.3%, 100%, 84.2%, 93.7%, 100%, 84.0% and 92.6%, respectively. It was concluded that all the differential diagnosis methods are useful. The test for duodenal drainage and elements is fast and accurate. It is helpful in the differential diagnosis of BA and non-BA etiologies of cholestasis. It shows good practical value clinically.

Management of occluded self-expanding biliary metal stents in malignant biliary disease.

BACKGROUND: Occlusion of self-expanding metal stents (SEMS) in malignant biliary obstruction occurs in up to 40% of patients. This study aimed to compare the different techniques to resolve stent occlusion in our collective of patients. METHODS: Patients with malignant biliary obstruction and occlusion of biliary metal stent at a tertiary referral endoscopic center were retrospectively identified between April 1, 1994 and May 31, 2014. The clinical records were further analyzed regarding the characteristics of patients, malignant strictures, SEMS, management strategies, stent patency, subsequent interventions, survival time and case charges. RESULTS: A total of 108 patients with biliary metal stent occlusion were identified. Seventy-nine of these patients were eligible for further analysis. Favored management was plastic stent insertion in 73.4% patients. Second SEMS were inserted in 12.7% patients. Percutaneous transhepatic biliary drainage and mechanical cleansing were conducted in a minority of patients. Further analysis showed no statistically significant difference in median overall secondary stent patency (88 vs. 143 days, P = 0.069), median survival time (95 vs. 192 days, P = 0.116), median subsequent intervention rate (53.4% vs. 40.0%, P = 0.501) and median case charge (€5145 vs. €3473, P = 0.803) for the treatment with a second metal stent insertion compared to plastic stent insertion. In patients with survival time of more than three months, significantly more patients treated with plastic stents needed re-interventions than patients treated with second SEMS (93.3% vs. 57.1%, P = 0.037). CONCLUSIONS: In malignant biliary strictures, both plastic and metal stent insertions are feasible strategies for the treatment of occluded SEMS. Our data suggest that in palliative biliary stenting, patients especially those with longer expected survival might benefit from second SEMS insertion. Careful patient selection is important to ensure a proper decision for either management strategy.

Functional assessment of hepatobiliary secretion by 11C-cholylsarcosine positron emission tomography.

Positron emission tomography (PET) with 11C-cholylsarcosine (11C-CSar), a radiolabelled synthetic N-methylglycine (sarcosine) conjugate of cholic acid, is a novel molecular imaging technique that enables quantitative assessment of the individual transport steps involved in hepatic secretion of conjugated bile acids. Here, we present the method and discuss its potential clinical and scientific applications based on findings in the first human study of healthy subjects and patients with cholestasis. We also present a clinical example of a patient studied during and six months after an episode of drug-induced cholestatic liver injury.

Efficacy and safety assessment of ERCP in patients with malignant biliary obstruction.

BACKGROUND: To assess the efficacy and safety of Endoscopic retrograde cholangiopancreatography (ERCP) for malignant biliary obstruction (MBO). MATERIAL AND METHODS: A review of all ERCP-procedures performed at Akershus University Hospital during the six year period between 2009-2014 was analysed. Data for the period 2009- 2013 were obtained retrospectively and prospectively for 2014. Patients with jaundice due to MBO were selected for the present study. RESULTS: A total of 210 patients (51% females), median age of 70 years (range 33-96) were included. The total number of procedures were 314, whereof 218 (69%) were successful and 96 (31%) were failures. 292 procedures were palliative and 22 procedures were intended as 'bridge to surgery' whereof 15 patients underwent surgery. Pancreatic carcinoma occurred in 105 (50%) patients and was the most common reason for MBO. Straight plastic stents (I-stents) were applied in 145 (74%), double-pigtail stents (JJ-stents) in 29 (15%), self-expanding metal stent (SEMS) in 18 (9%) procedures and in 3 procedures (1.5%) an I-stent was inserted through an indwelling SEMS. Median duration of stentpatency in months was 2 (range 0-74) for I-stent, 1 (range 0-29) for JJ-stent and 4 (range 0-29) for SEMS. The rates of complication and mortality due to complication were 8.9% and 1.3% per procedure. CONCLUSION: Adequate drainage of MBO by ERCP was obtained in 69%. The rates of complication and procedure related mortality were at acceptable levels.

Comparison of patency and cost-effectiveness of self-expandable metal and plastic stents used for malignant biliary strictures: a Polish single-center study.

INTRODUCTION: Most patients with malignant biliary obstruction are suited only for palliation by endoscopic drainage with plastic stents (PS) or self-expandable metal stents (SEMS). OBJECTIVE: To compare the clinical outcome and costs of biliary stenting with SEMS and PS in patients with malignant biliary strictures. PATIENTS AND METHODS: A total of 114 patients with malignant jaundice who underwent 376 endoscopic retrograde biliary drainage (ERBD) were studied. RESULTS: ERBD with the placement of PS was performed in 80 patients, with one-step SEMS in 20 patients and two-step SEMS in 14 patients. Significantly fewer ERBD interventions were performed in patients with one-step SEMS than PS or the two-step SEMS technique (2.0±1.12 vs. 3.1±1.7 or 5.7±2.1, respectively, P<0.0001). The median hospitalization duration per procedure was similar for the three groups of patients. The patients' survival time was the longest in the two-step SEMS group in comparison with the one-step SEMS and PS groups (596±270 vs. 276±141 or 208±219 days, P<0.001). Overall median time to recurrent biliary obstruction was 89.3±159 days for PS and 120.6±101 days for SEMS (P=0.01). The total cost of hospitalization with ERBD was higher for two-step SEMS than for one-step SEMS or PS (1448±312, 1152±135 and 977±156&OV0556;, P<0.0001). However, the estimated annual cost of medical care for one-step SEMS was higher than that for the two-step SEMS or PS groups (4618, 4079, and 3995&OV0556;, respectively). CONCLUSION: Biliary decompression by SEMS is associated with longer patency and reduced number of auxiliary procedures; however, repeated PS insertions still remain the most cost-effective strategy.

[Cost-effectiveness trial of self-expandable metal stents and plastic biliary stents in malignant biliary obstruction]. / A fém- és muanyag stentek költséghatékonysága malignus epeúti szukületek esetében - összehasonlító vizsgálat.

INTRODUCTION: Self-expandable metal and plastic stents can be applied in the palliative endoscopic treatment of patients with unresectable malignant biliary obstruction. The use of metal stentsis recommended if the patient's life expectancy is more than four months. AIM: To compare the therapeutic efficacy and cost-effectiveness of metal and plastic stents in the treatment of malignant biliary obstruction. METHOD: The authors retrospectively enrolled patients who received metal (37 patients) or plastic stent (37 patients). The complication rate, stent patency and cumulative cost of treatment were assessed in the two groups. RESULTS: The complication rate of metal stents was lower (37.84% vs. 56.76%), but the stent patency was higher compared with plastic stents (19.11 vs. 8.29 weeks; p = 0.0041). In the plastic stent group the frequency of hospitalization of patients in context with stent complications (1.18 vs. 2.32; p = 0.05) and the necessity of reintervention for stent dysfunction (17 vs. 27; p = 0.033) were substantially higher. In this group multiple stent implantation raised the stent patency from 7.68 to 10.75 weeks. There was no difference in the total cost of treatment of malignant biliary obstruction between the two groups (p = 0.848). CONCLUSIONS: Considering the cost of treatment and the burden of patients the authors recommend self-expandable metal sten timplantation if the life expectancy of patients is more than two months. In short survival cases multiple plastic stent implantation is recommended.

Contrast-enhanced micro-computed tomography using ExiTron nano6000 for assessment of liver injury.

AIM: To explore the potential of contrast-enhanced computed tomography (CECT) using ExiTron nano6000 for assessment of liver lesions in mouse models. METHODS: Three mouse models of liver lesions were used: bile duct ligation (BDL), lipopolysaccharide (LPS)/D-galactosamine (D-GalN), and alcohol. After injection with the contrast agent ExiTron nano6000, the mice were scanned with micro-CT. Liver lesions were evaluated using CECT images, hematoxylin and eosin staining, and serum aminotransferase levels. Macrophage distribution in the injury models was shown by immunohistochemical staining of CD68. The in vitro studies measured the densities of RAW264.7 under different conditions by CECT. RESULTS: In the in vitro studies, CECT provided specific and strong contrast enhancement of liver in mice. CECT could present heterogeneous images and densities of injured livers induced by BDL, LPS/D-GalN, and alcohol. The liver histology and immunochemistry of CD68 demonstrated that both dilated biliary tracts and necrosis in the injured livers could lead to the heterogeneous distribution of macrophages. The in vitro study showed that the RAW264.7 cell masses had higher densities after LPS activation. CONCLUSION: Micro-CT with the contrast agent ExiTron nano6000 is feasible for detecting various liver lesions by emphasizing the heterogeneous textures and densities of CECT images.

Significance of peribiliary oedema on computed tomography in diagnosis and severity assessment of acute cholangitis.

OBJECTIVES: To evaluate usefulness of peribiliary oedema on computed tomography (CT) in diagnosing acute cholangitis and assessing its severity. MATERIALS AND METHODS: Sixty patients (male 59%, mean age 67.3 years) who underwent endoscopic retrograde biliary drainage (ERBD) for suspected biliary obstruction within 6h after contrast-enhanced CT were evaluated. Two radiologists performed a consensus evaluation of CT for the presence of peribiliary oedema. Patients were divided into the cholangitis group and the non-cholangitis group based on clinical and ERBD findings, and CT results were compared between the two groups. In the cholangitis group, laboratory values and blood culture results were compared between those with and without peribiliary oedema. Chi-squared test was used for analyses. RESULTS: Of 60 enrolled patients, there were 46 patients in the cholangitis group and 14 patients in the non-cholangitis group. Peribiliary oedema was seen in 24/46 (52.2%) patients in the cholangitis group and 3/14 (23.3%) patients in the non-cholangitis group (p=0.043). In the cholangitis group, positive blood culture was seen in 12/24 (50%) patients with peribiliary oedema and 4/22 (18.1%) patients without it (p=0.03). CONCLUSIONS: Peribiliary oedema appears to be useful for diagnosis and severity assessment of acute cholangitis.

Endoscopic ultrasonography guided biliary drainage: summary of consortium meeting, May 7th, 2011, Chicago.

Endoscopic retrograde cholangiopancreatography (ERCP) has become the preferred procedure for biliary or pancreatic drainage in various pancreatico-biliary disorders. With a success rate of more than 90%, ERCP may not achieve biliary or pancreatic drainage in cases with altered anatomy or with tumors obstructing access to the duodenum. In the past those failures were typically managed exclusively by percutaneous approaches by interventional radiologists or surgical intervention. The morbidity associated was significant especially in those patients with advanced malignancy, seeking minimally invasive interventions and improved quality of life. With the advent of biliary drainage via endoscopic ultrasound (EUS) guidance, EUS guided biliary drainage has been used more frequently within the last decade in different countries. As with any novel advanced endoscopic procedure that encompasses various approaches, advanced endoscopists all over the world have innovated and adopted diverse EUS guided biliary and pancreatic drainage techniques. This diversity has resulted in variations and improvements in EUS Guided biliary and pancreatic drainage; and over the years has led to an extensive nomenclature. The diversity of techniques, nomenclature and recent progress in our intrumentation has led to a dedicated meeting on May 7(th), 2011 during Digestive Disease Week 2011. More than 40 advanced endoscopists from United States, Brazil, Mexico, Venezuela, Colombia, Italy, France, Austria, Germany, Spain, Japan, China, South Korea and India attended this pivotal meeting. The meeting covered improved EUS guided biliary access and drainage procedures, terminology, nomenclature, training and credentialing; as well as emerging devices for EUS guided biliary drainage. This paper summarizes the meeting's agenda and the conclusions generated by the creation of this consortium group.

A health technology assessment of transient elastography in adult liver disease.

BACKGROUND: An estimated one in 10 Canadians have some form of liver disease. The reference standard for staging and monitoring liver fibrosis is percutaneous liver biopsy--an invasive procedure associated with risks and complications. Transient elastography (TE) represents a noninvasive, ultrasound-based alternative. OBJECTIVE: To assess the efficacy of TE compared with liver biopsy for fibrosis staging in adults with five common types of liver disease: hepatitis B, hepatitis C, nonalcoholic fatty liver disease, cholestatic liver disease and complications post-liver transplantation. METHODS: A systematic review of published and grey literature from 2001 to June 2011 was conducted. Included were observational studies evaluating the accuracy of TE using liver biopsy as the comparator. An economic model was developed to estimate the cost per correct diagnosis gained with liver biopsy compared with TE. Identification of moderate fibrosis (stages 2 to 4) and cirrhosis (stage 4) were considered. RESULTS: Fifty-seven studies were included in the review. The diagnostic accuracy of TE for the five clinical subgroups had sensitivities ranging from 0.67 to 0.92 and specificities ranging from 0.72 to 0.95. Liver biopsy was associated with an additional $1,427 to $7,030 per correct diagnosis gained compared with TE. The model was sensitive to the sensitivity and specificity of TE and the prevalence of fibrosis. CONCLUSIONS: TE is an accurate diagnostic method in patients with moderate fibrosis or cirrhosis. TE is less effective but less expensive than liver biopsy. Systemic implementation of TE should be considered for the noninvasive assessment of liver fibrosis.

Hepatobiliary scintigraphy for the assessment of biliary strictures after pediatric liver transplantation.

HBS is used in the management of liver transplantation, a significant complication of which is biliary stricture. Strictures may be intraparenchymal within segments and main duct (non-anastomotic) or at the biliary-enteric anastomosis (anastomotic). Strictures are definitively diagnosed, and often managed, by PTC. This is invasive, technically challenging, and requires general anesthesia in young children. HBS may allow early detection of these complications and is non-invasive. The aim of this study was to review the scintigraphic pattern of biliary strictures using (99m)TcDISIDA HBS following pediatric orthotopic liver transplantation, and to assess its role in the diagnostic algorithm of suspected biliary strictures. All available hepatobiliary studies performed post-transplant in 101 episodes of liver transplantation in 92 pediatric patients were reviewed. Twenty-three (23%) patients had known biliary strictures. Twenty-two patients had adequate studies available for review; five had intrahepatic (non-anastomotic) strictures alone, nine had a stricture of the anastomosis alone, and eight had both intrahepatic and anastomotic strictures. HBS patterns (either segmental or global changes) correlated very highly with clinically significant biliary strictures. All patients with known strictures had abnormal HBS; hence, in patients with abnormal liver function tests post-liver transplant, a normal HBS makes strictures very unlikely. We propose that HBS can thus be used to determine if further investigation is required.

Intraductal ultrasonography for the assessment of preoperative biliary and pancreatic strictures.

Diseases of the biliary and pancreatic ducts are often difficult to diagnose. Although transcutaneous ultrasonography, computer tomography and magnetic resonance greatly improved in performance, two major problems have not been completely solved yet: first, the differentiation of malignant and benign bile duct strictures, and, second, the assessment of the resectability of carcinomas underlying biliary strictures. Ultrasound probes can be inserted through the working channel of the duodenoscope and passed selectively both into the biliary and pancreatic ducts. Ultrasound frequencies of 20 or 30 MHz enable a penetration of up to 2 cm and a resolution of 0.07 to 0.18 mm. The main clinical indication for intraductal ultrasonography of the biliary tract is obstructive jaundice, which requires assessment of bile duct strictures and local tumor staging. Miniprobes can contribute to the differential diagnosis of strictures localized in the main pancreatic duct, and also to localizing small endocrine tumors. Small tumors of the papilla of Vater can be staged before a possible endoscopic resection. Feasibility of the method is excellent in expert hands with almost no added morbidity.

Multidetector computed tomography cholangiography with multiplanar reformation for the assessment of patients with biliary obstruction.

BACKGROUND: We sought to evaluate the diagnostic use of multidetector computed tomography (MDCT) cholangiography with multiplanar reformation (MPR) for the assessment of patients with biliary obstruction. METHODS: MDCT cholangiography with the MPR technique was performed in 58 patients who were thought to have biliary obstruction. No cholangiographic contrast agent was administered. MRCP in 24 patients, Endoscopic retrograde cholangiopancreatography (ERCP) in 46 patients and percutaneous transhepatic cholangiography (PTC) in 24 patients were performed. Eighteen patients underwent biopsy or surgery. The findings on MDCT cholangiography were compared with those of MRCP, ERCP, PTC, biopsy or surgery. RESULTS: The findings of MDCT cholangiography were as follows: choledocholithiasis (n = 34, 56.7%), malignant stricture (n = 14, 23.3%), benign stricture (n = 1, 1.7%), and cholelithiasis (n = 11, 18.3%). A small common bile duct (CBD) stone in one patient could not be detected on MDCT cholangiography. One patient with a small stone in distal CBD detected on MDCT cholangiography had no stone on ERCP. Two patients with initial diagnoses of CBD stones by MDCT cholangiography were disclosed to have malignant bile duct stricture by reference examination. The sensitivity and specificity of MDCT cholangiography for the diagnosis of bile duct stones were 96.9% and 96.2%, respectively. The sensitivity and specificity of MDCT cholangiography for the diagnosis of bile duct stricture were 85.7% and 100%, respectively. The overall accuracy of MDCT cholangiography for the diagnoses of the causes of biliary obstruction was 89.8%. CONCLUSION: MDCT cholangiography with the MPR technique is a fast and non-invasive technique with relatively high sensitivity and specificity for the diagnoses of the causes of biliary obstruction.

Intrabiliary MR imaging: assessment of biliary obstruction with use of an intraluminal MR receiver coil.

PURPOSE: The primary aim of this study was to determine whether intrabiliary magnetic resonance (MR) imaging is feasible in a clinical setting and to optimize MR imaging parameters for the technique. In addition, it was attempted to determine the accuracy of intrabiliary MR imaging in the setting of biliary obstruction of unknown cause. MATERIALS AND METHODS: Intrabiliary MR was performed prospectively in 15 patients with biliary obstruction of unknown cause. A 0.030-inch MR intravascular receiver coil was placed in an existing biliary tube. Intrabiliary MR was performed on a 1.5-T system. T1-weighted, T2-weighted, and single-shot fast spin-echo images were acquired. T1-weighted images were also acquired after the administration of a gadolinium contrast agent. Signal intensity analysis was conducted in the region of the common bile duct. Accuracy of intrabiliary MR, computed tomography (CT), MR, and cholangiography were determined by correlation with surgical pathologic findings. RESULTS: Intrabiliary MR was successfully performed in 14 of 15 patients. MR examinations were performed in less than 1 hour. The signal-to-noise ratio in the region of the common bile duct with the intrabiliary MR technique was increased by a factor of 9 compared with standard surface-coil MR imaging (P < .00001). The mean n-plane resolution achieved was 740 +/- 20 microm x 1,150 +/- 20 microm obtained with use of a field of view of 18 cm x 18 cm (range, 15-24 cm) and a matrix of 256 x 160. Of the pulse sequences tested, the gadolinium-enhanced T1-weighted image was the best for identifying tumor and delineating tumor margins. Intrabiliary MR had a higher sensitivity than CT (100% vs 50%), a higher specificity than cholangiography (80% vs 20%), and a better correlation (P = .015) with surgical pathologic findings than CT, MR imaging, or cholangiography. CONCLUSIONS: Intrabiliary MR was well tolerated in a clinical setting and provided high spatial resolution and excellent contrast between the biliary lumen and adjacent structures. Intrabiliary MR demonstrated an advantage in detecting the presence or absence of biliary malignancies compared with currently available standard imaging techniques. The technique may be useful to evaluate biliary obstruction of unknown cause.

MDCT cholangiography with volume rendering for the assessment of patients with biliary obstruction.

OBJECTIVE: We sought to evaluate the diagnostic utility of MDCT cholangiography with volume rendering in the evaluation of patients with suspected biliary tree obstruction. SUBJECTS AND METHODS: MDCT was performed in 34 patients who were thought to have biliary obstruction. Portal venous phase scanning was initiated 70 sec after the IV infusion of 150 mL of contrast agent, and no cholangiographic contrast agent was administered. Three-dimensional MDCT cholangiographic images were produced using volume rendering. ERCP was performed in 26 patients, and percutaneous transhepatic cholangiography (PTC) was performed in five patients; 17 patients underwent biopsy or surgery. The findings on MDCT cholangiography were compared with those of ERCP, PTC, biopsy, or surgery. RESULTS: The correct diagnosis was made on MDCT cholangiography for 14 (93%) of the 15 patients with a biliary stone and in 16 (94%) of the 17 patients with malignant biliary obstruction. Microlithiasis in one patient could not be detected on MDCT cholangiography. One patient with polypoid adenocarcinoma and one patient with normal findings were incorrectly diagnosed with a biliary stone on the basis of MDCT cholangiography. In one of the two patients with a benign stricture, the stricture was incorrectly diagnosed as malignant. For the diagnosis of biliary stone, sensitivity and specificity of MDCT cholangiography were 93% and 89%, respectively. For the diagnosis of malignant obstruction, sensitivity and specificity were both 94%. The accuracy of the technique for the diagnosis of the cause of biliary obstruction was 83.3%. CONCLUSION: MDCT cholangiography with volume rendering is a noninvasive and fast imaging technique with high sensitivity and specificity for the diagnosis of the cause of biliary tree obstruction. It is a promising diagnostic tool for the assessment of patients with bile duct obstructions.

Per-rectal portal scintigraphy is complementary to ultrasonography and endoscopy in the assessment of portal hypertension in children with chronic cholestasis.

UNLABELLED: We evaluated the clinical usefulness of 99mTc-pertechnetate per-rectal portal scintigraphy (PPS) in the assessment of portal circulation in children with chronic cholestasis. METHODS: PPS percentage shunt index (%SI) (the amount of radionuclide that shunts the liver and reaches the systemic blood after injection in the rectum) was measured in 22 children (mean age, 7.2 +/- 4.9 y) and compared with established clinical, laboratory, and endoscopic and imaging parameters of portal hypertension (PH). Fourteen children had surgically treated biliary atresia, and 8 had chronic intrahepatic cholestasis. Six clinically well children served as control subjects. RESULTS: The %SI was 14.3 +/- 3.1 and 34.7 +/- 18.8 in controls and in patients, respectively (P < 0.01). A cutoff of 19% correctly allocated 100% of controls and 86% of patients. Mean %SI values were significantly higher in patients with biliary atresia, a high risk of pretransplantation death, esophageal varices (EV) at endoscopy, and an abnormal value for the ratio of lesser omentum thickness to abdominal aorta diameter (LO/Ao) at ultrasonography. Correlations between %SI values and several ultrasonographic continuous variables were statistically significant only for LO/Ao ratios (r = 0.51; P = 0.005) and spleen longitudinal diameters (r = 0.53; P = 0.01). The presence of EV could correctly be predicted only when values of %SI were greater than 30% (100% specificity; 56% sensitivity). Endoscopic and PPS findings agreed for a diagnosis of PH with EV in 3 of 7 patients with normal or borderline ultrasonographic LO/Ao ratios. PPS patterns and %SI values became normal in 3 children who underwent liver transplantation. CONCLUSION: In children with chronic cholestasis, PPS may be an advantageous, minimally invasive tool complementary to ultrasonography and endoscopy for better assessment and follow-up of PH before and after liver transplantation.