Using contrast-enhanced MR cholangiography with IV mangafodipir trisodium (Teslascan) to evaluate bile duct leaks after cholecystectomy: a prospective study of 11 patients

Magnetic Resonance Cholangiography Diagnosing Post-cholecystectomy Biliary Injuries

OBJECTIVE

This study aimed to determine the diagnostic performance of contrasted magnetic resonance cholangiography for detecting bile duct lesions following cholecystectomy.

MATERIALS AND METHODS

A retrospective case series study was conducted that included patients over 18 years of age with suspected bile duct injury after cholecystectomy, who underwent contrasted magnetic resonance cholangiography, and who also had endoscopic retrograde cholangiopancreatography, surgery, or subsequent clinical follow-up. The images were interpreted by two radiologists who assigned the type of lesion according to the Strasberg classification. Qualitative variables were represented by frequencies and proportions, while quantitative variables were described using measures of central tendency and dispersion. Sensitivity, specificity, and predictive values were assessed, along with interobserver variability, using the kappa index.

RESULTS

We included 20 patients with a median age of 51.5 years (interquartile range: 35), and 14 (70%) were women. In all 20 patients, lesions were identified on magnetic resonance cholangiography, of which 19 were confirmed with the gold standard for a positive predictive value of 100% (hepatobiliary-specific contrast agents) and 92% (extracellular contrast). The most frequent lesions were Strasberg E2 and E4 in five patients each. The kappa index was 1 in determining the presence or absence of bile duct injury and 0.9 in the Strasberg classification.

CONCLUSION

Contrasted magnetic resonance cholangiography is a method with high positive predictive value and almost perfect interobserver agreement for diagnosing bile duct lesions after cholecystectomy.

Clinical presentation, management and outcomes of bile duct injuries after laparoscopic cholecystectomy: a 15-year single-center experience in Vietnam

Objectives

To evaluate the clinical presentation, management, and outcomes of bile duct injuries (BDIs) after laparoscopic cholecystectomy (LC).

Methods

This is a case series of 28 patients with BDIs after LC treated at a tertiary hospital in Vietnam during the 2006-2021 period. The BDI's clinical presentations, Strasberg classification types, management methods, and outcomes were reported.

Results

BDIs were diagnosed intraoperatively in 3 (10.7%) patients and postoperatively in 25 (89.3%). The BDI types included Strasberg A (13, 46.4%), D (1, 3.6%), E1 (1, 3.6%), E2 (4, 14.3%), E3 (5, 17.9%), D + E2 (2, 7.1%), and nonclassified (2, 7.1%). Of the postoperative BDIs, the injury manifested as biliary obstruction (18, 72.0%), bile leak (5, 20.0%), and mixed scenarios (2, 8.0%). Regarding diagnostic methods, endoscopic retrograde cholangiopancreatography (ERCP) was more useful in bile leak scenarios, while multislice computed tomography, magnetic resonance cholangiopancreatography, and percutaneous transhepatic cholangiography were more useful in biliary obstruction scenarios. All 28 BDIs were successfully treated. ERCP with stenting was very effective in the majority of Strasberg A BDIs. For more complex BDI types, hepaticocutaneous jejunostomy was a safe and effective approach. The in-hospital morbidities included postoperative pneumonia (2, 10.7%) and biliary-enteric anastomosis leakage (1, 5.4%). There was no cholangitis or anastomotic stenosis during the follow-up after discharge (median 18 months).

Conclusions

The majority of BDIs are type A and diagnosed postoperatively. ERCP is effective for the majority of Strasberg A BDIs. For major and complex BDIs, hepaticocutaneous jejunostomy is a safe and effective approach.

Ducts of Luschka as a rare cause of postoperative biloma. MRCP findings

Laparoscopic cholecystectomy can be complicated by a post- operative biloma. Bile leak from the duct of Luschka is reported to be the second most frequent cause, reported in 0.15%-2% of the patients. This case report aims to underline the significance of this anatomic variation and how the management of the aforementioned complication can be facilitated by MRI- MRCP. A 78 year old male patient underwent an elective laparoscopic cholecystectomy and was found to have a post-operative biloma. An MRCP was carried out to visualize the bile tree and bile leak was identified to be originated from a duct of Luschka. The patient was referred for an ERCP, sphingterotomy and placement of biliary stent to release the pressure in the bile ducts. In the next few days the bile leak was controlled and eventually ceased. The patient was discharged free of symptoms and no sign of bile leak was to be found on his follow up imaging. In comparison with other imaging modalities picturing the bile tree, MRCP fits the ideal profile to be used as a first line choice for clinicians, as it offers detailed anatomical images with high contrast between bile and adjacent tissues, without using any contrast agent or radiation.

Gd-EOB-DTP-enhanced MRC in the preoperative percutaneous management of intra and extrahepatic biliary leakages: does it matter?

Postoperative bile leakage is a common complication of abdominal surgical procedures and a precise localization of is important to choose the best management. Many techniques are available to correctly identify bile leaks, including ultrasound (US), computed tomography (CT) or magnetic resonance imaging (MRI), being the latter the best to clearly depict "active" bile leakages. This paper presents the state of the art algorithm in the detection of biliary leakages in order to plan a percutaneous biliary drainage focusing on widely available and safe contrast agent, the Gb-EOB-DPA. We consider its pharmacokinetic properties and impact in biliary imaging explain current debates to optimize image quality. We report common sites of leakage after surgery with special considerations in cirrhotic liver to show what interventional radiologists should look to easily detect bile leaks.

Recent Advances in Polyesters for Biomedical Imaging

Several synthetic materials exhibiting contrast imaging properties have become vital to the field of biomedical imaging. Polymeric biomaterials and metals are commonly used imaging agents and can assist in the monitoring of therapy response, migration, degradation, changes in morphology, defects, and image-guided surgery. In comparison to metals, most bio and synthetic polymers lack inherent imaging properties. Polymeric biomaterials, specifically polyesters, have gained a considerable amount of attention due to their unique properties including biocompatibility, biodegradation, facile synthesis, and modification capability. Polyester implants and nanomaterials are available on the market or are in clinical trials for many applications including: dental implants, cranio-maxilofacial implants, soft tissue sutures and staples, abdominal wall repair, tendon and ligament reconstruction, fracture fixation devices, and coronary drug eluting stents. This review aims to provide a summary of the recent developments of polyesters with bioimaging contrast properties. The three main approaches to prepare bioimaging polyesters (coating, encapsulation, and functionalization) are discussed in depth. Furthermore, commonly used imaging modalities including X-ray computed tomography, magnetic resonance imaging, ultrasound, fluorescence, and radionucleotide polyester contrast agents are highlighted. In each section, examples of impactful bioimaging polyesters in the five major imaging modalities are evaluated.

Biliary imaging: multimodality approach to imaging of biliary injuries and their complications

Although traumatic and iatrogenic bile leaks are rare, they have become more prevalent in recent years due to an increased propensity toward nonsurgical management of patients with liver trauma and an overall increase in the number of hepatobiliary surgeries being performed. Because clinical signs and symptoms of bile leaks are nonspecific and delay in the recognition of bile leaks is associated with high morbidity and mortality rates, imaging is crucial for establishing an early diagnosis and guiding the treatment algorithm. At computed tomography or ultrasonography, free or contained peri- or intrahepatic low-attenuation (low-density) fluid in the setting of recent trauma or hepatobiliary surgery should raise suspicion for a bile leak. Hepatobiliary scintigraphy and magnetic resonance (MR) cholangiopancreatography with hepatobiliary contrast agents can help detect active or contained bile leaks. MR cholangiopancreatography with hepatobiliary contrast agents has the added advantage of being able to help localize the bile leak, which in turn can help determine if endoscopic management is sufficient or if surgical management is warranted. Endoscopic retrograde cholangiopancreatography may provide diagnostic confirmation and concurrent therapy when nonsurgical management is pursued. A multimodality imaging approach is helpful in diagnosing traumatic or iatrogenic biliary injuries, accurately localizing a bile leak, and determining appropriate treatment.

Detection and localization of bile duct leaks after cholecystectomy using Gd-EOB-DTPA-enhanced MR cholangiography: retrospective study of 16 patients

OBJECTIVE

To determine if gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) cholangiography can detect and localize bile duct leaks in postcholecystectomy patients.

MATERIAL AND METHODS

Four blinded independent radiologists performed a retrospective review of 16 consecutive patients who underwent MR cholangiography with intravenous Gd-EOB-DTPA for the evaluation of possible biliary leak. Image quality, ductal opacification, and presence and location of any bile leak were evaluated. An independent observer determined the criterion standard using a consensus of all chart, clinical, and imaging findings.

RESULTS

All 6 bile leaks confirmed at endoscopic retrograde cholangiopancreatography were diagnosed by all reviewers (sensitivity, 100%). Of the 10 patients with no leak, only one reader incorrectly diagnosed a bile leak in a single case (specificity, 98%). The accuracy for detection of the site of leak with Gd-EOB-DTPA-enhanced MR cholangiography was 80%.

CONCLUSION

Gadolinium-EOB-DTPA-enhanced MR can detect bile leaks with a high sensitivity and specificity.

Diagnosis of postoperative bile leak and accurate localization of the site of leak by gadobenate dimeglumine-enhanced MR cholangiography in a child

Postoperative bile leaks are difficult to diagnose because signs and symptoms are nonspecific, and definitive diagnosis requires a drainage catheter to be placed that drains frank bile or fluid that turns out bile on laboratory analysis. Hepatobiliary scintigraphy, endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC) have been traditionally used to diagnose bile leak. Scintigraphy has poor spatial resolution and cannot localize the site of leak, ERCP may not be possible with altered postoperative anatomy and PTC is invasive and difficult to perform in the absence of dilated ducts. Recently, contrast-enhanced MR cholangiography using hepatobiliary-specific contrast media has been shown to be a noninvasive, safe way to diagnose and localize the site of bile leak in adults. We report a case of postoperative bile leak after choledochal cyst resection in a child in whom diagnosis was confirmed and the site of leak was accurately localized using gadobenate-enhanced MR cholangiography. This case demonstrates the potential of hepatobiliary-specific contrast media to diagnose postoperative bile leak and accurately localize the site of the leak in children noninvasively.

Non-invasive detection of biliary leaks using Gd-EOB-DTPA-enhanced MR cholangiography: comparison with T2-weighted MR cholangiography

Objective

To evaluate the added role of T1-weighted (T1w) gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance cholangiography (MRC) compared with T2-weighted MRC (T2w-MRC) in the detection of biliary leaks.

Methods

Ninety-nine patients with suspected biliary complications underwent routine T2w-MRC and T1w contrast-enhanced (CE) MRC using Gd-EOB-DTPA to identify biliary leaks. Two observers reviewed the image sets separately and together. MRC findings were compared with those of surgery and percutaneous transhepatic cholangiopancreatography. The sensitivity, specificity and accuracy of the techniques in identifying biliary leaks were calculated.

Results

Accuracy of locating biliary leaks was superior with the combination of Gd-EOB-DTPA-enhanced MRC and T2w-MRC (P < 0.05).The mean sensitivities were 79 % vs 59 %, and the mean accuracy rates were 84 % vs 58 % for combined CE-MRC and T2w-MRC vs sole T2w-MRC. Nineteen out of 21 patients with biliary-cyst communication, 90.4 %, and 12/15 patients with post-traumatic biliary extravasations, 80 %, were detected by the combination of Gd-EOB-DTPA-enhanced MRC and T2w-MRC images, P < 0.05.

Conclusions

Gd-EOB-DTPA-enhanced MRC yields information that complements T2w-MRC findings and improves the identification and localisation of the bile extravasations (84 % accuracy, 100 % specificity, P < 0.05). We recommend Gd-EOB-DTPA-enhanced MRC in addition to T2w-MRC to increase the preoperative accuracy of identifying and locating extravasations of bile.

Key Points

• Magnetic resonance cholangiography (MRC) does not always detect bile leakage and cysto-biliary communications.

• Gd-EOB-DTPA-enhanced MRC helps by demonstrating extravasation of contrast material into fluid collections.

• Gd-EOB-DTPA-enhanced MRC also demonstrates the leakage site and bile duct injury type.

• Combined Gd-EOB-DTPA-enhanced and T2w-MRC can provide comprehensive information about biliary system.

• Gd-EOB-DTPA-enhanced MRC is non-invasive and does not use ionising radiation.

Early phase detection of bile leak after hepatobiliary surgery: value of Gd-EOB-DTPA-enhanced MR cholangiography

PURPOSE

To assess the value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MR cholangiography for the detection of bile leaks after hepatobiliary surgery.

METHODS

Twenty-three patients with symptoms suggestive of bile leak underwent conventional fat-suppressed T1- and T2-weighted MR cholangiography followed by Gd-EOB-DTPA-enhanced MR cholangiography using gradient-echo (GRE) T2-weighted sequences and fat-suppressed T1-weighted 3D gradient-echo sequences 20 min after an intravenous bolus of Gd-EOB-DTPA. The results of Gd-EOB-DTPA-enhanced MR cholangiography correlated with clinical findings, surgical repair, and the results of endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography.

RESULTS

The results of Gd-EOB-DTPA-enhanced MR cholangiography were negative in 13 patients (cholecystectomy 5, liver transplantation 2, liver resection for focal lesions 2, cholangiocarcinoma 1, and partial hepatectomy after liver injury 1). In 10 patients in whom bile leaks were detected, this complication occurred after liver resection for focal lesions in 3, cholecystectomy in 4, liver transplantation in 2, and liver resection for intrahepatic cholangiocarcinoma in 1. The diagnostic accuracy of Gd-EOB-DTPA-enhanced MR for the detection or exclusion of bile leaks was 100%.

CONCLUSIONS

Gd-EOB-DTPA-enhanced MR cholangiography is a highly reliable technique for the detection of bile leaks after hepatobiliary surgery and may avoid the use of other, potentially risky invasive diagnostic techniques.

Double gall bladder-a rare entity

Cholecystectomy is the most commonly performed operation in surgery. Variations inanatomical disposition are not infrequent. However variations in number of cystic ductand gall bladder is quiet rare. This poses a diagnostic and management problem withcomplications during surgery and missed gall bladder being reported in world literature. We here by report a case of double gall bladder with double cystic duct that was managed by laparoscopic surgery.

Contrast-enhanced MR cholangiography (MRCP) with GD-EOB-DTPA in evaluating biliary complications after surgery

PURPOSE

We assessed the usefulness of contrast-enhanced magnetic resonance cholangiography (CE-MRC) with liver-specific contrast agent in evaluating the biliary tree after hepatic surgery.

MATERIALS AND METHODS

A total of 142 patients with suspected biliary complications after liver surgery underwent hepatobiliary MR before and after administration of gadolinium ethoxy benzylic diethylenetriamine pentaacetic acid (Gd-EOB-DTPA). Unenhanced MR cholangiopancreatography (MRCP) and postcontrast MRC were obtained in all patients. Blinded image evaluation and semiquantitative analysis comparing MRCP and CE-MRC were performed by two experienced radiologists.

RESULTS

In all cases, optimal postcontrast visualisation of the biliary tract was obtained. In 22 patients, a postsurgical biliary complication was confirmed. MRCP detected 64% of lesions, but in 36% of cases, an alteration was only suspected but not clearly defined. CE-MRC allowed definite diagnosis in 100% of cases.

CONCLUSIONS

Hepatobiliary-specific contrast agents allow for accurate and extensive study of biliary tract alterations, especially in assessing postsurgical complications.

Symptomatic "H" type duplex gallbladder

A case of ductular type duplex gallbladder is presented that was diagnosed by magnetic resonance cholangiopancreatography and managed by laparoscopy.

Gallbladder duplication with an incidence at autopsy of about 1 in 4000 is important in clinical practice, because it may cause some clinical, surgical, and diagnostic problems. Preoperative identification of this rare anomaly avoids biliary injuries and the other consequences of missed diagnosis. In this report, we present a case of ductular type duplex gallbladder diagnosed preoperatively by magnetic resonance cholangiopancreatography (MRCP) and ultrasound and managed successfully by laparoscopy.

Evaluation of the efficacy and reproducibility of cholangiopancreatography by magnetic resonance for detecting biliary complications following orthotopic liver transplantation

PURPOSE

To evaluate the accuracy and reproducibility of magnetic resonance cholangiopancreatography (MRCP) in the detection of biliary complications in liver transplanted patients.

METHODS

A study was conducted, with blinded review of 28 MRCP exams of 24 patients submitted to liver transplantation. The images were reviewed by two independent observers, at two different moments, regarding the degree of biliary tree visualization and the presence or absence of biliary complications. The MRCP results were compared, when negative, to at least 3 months of clinical and biochemical follow-up, and when positive, to the findings at surgery or endoscopic retrograde cholangiopancreatography (ERCP).

RESULTS

The degree of intrahepatic biliary tree visualization was considered good or excellent in 78.6% and 82.1% of the exams by the two observers and visualization of the donor duct, recipient duct and biliary anastomosis was considered good or excellent in 100% of the exams, by both observers. Six biliary complications were detected (21.4%), all of them anastomotic strictures. Intra and interobserver agreement were substantial or almost perfect (kappa k values of 0.611 to 0.804) for the visualization of the biliary tree and almost perfect (k values of 0.900 to 1.000) for the detection of biliary complications. MRCP achieved 100% sensitivity, 95.45% specificity, 85.7% positive predictive value and 100% negative predictive value for the detection of biliary complications.

CONCLUSIONS

MRCP is an accurate examination for the detection of biliary complications after orthotopic liver transplantation and it is a highly reproducible method in the evaluation of the biliary tree of liver transplanted patients.

Post-cholecystectomy syndrome: spectrum of biliary findings at magnetic resonance cholangiopancreatography

Post-cholecystectomy syndrome (PCS) is defined as a complex of heterogeneous symptoms, consisting of upper abdominal pain and dyspepsia, which recur and/or persist after cholecystectomy. Nevertheless, this term is inaccurate, as it encompasses biliary and non-biliary disorders, possibly unrelated to cholecystectomy. Biliary manifestations of PCS may occur early in the post-operative period, usually because of incomplete surgery (retained calculi in the cystic duct remnant or in the common bile duct) or operative complications, such as bile duct injury and/or bile leakage. A later onset is commonly caused by inflammatory scarring strictures involving the sphincter of Oddi or the common bile duct, recurrent calculi or biliary dyskinesia. The traditional imaging approach for PCS has involved ultrasound and/or CT followed by direct cholangiography, whereas manometry of the sphincter of Oddi and biliary scintigraphy have been reserved for cases of biliary dyskinesia. Because of its capability to provide non-invasive high-quality visualisation of the biliary tract, magnetic resonance cholangiopancreatography (MRCP) has been advocated as a reliable imaging tool for assessing patients with suspected PCS and for guiding management decisions. This paper illustrates the rationale for using MRCP, together with the main MRCP biliary findings and diagnostic pitfalls.

[Imaging of the postoperative biliary tract]

For a long time, imaging of the biliary tract after surgical procedures was performed with invasive procedures such as endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography. Due to recent advances in diagnostic imaging, non-invasive techniques are now favored. While US remains the initial imaging modality, it is frequently followed by CT and/or MRCP. Image interpretation should always be performed in keeping with clinical and laboratory findings as well as the type of surgical procedure. The most appropriate imaging modality is selected based on these data. In patients with jaundice or biliary tract stenosis, MRCP, with use of an optimal technique and 3D acquisition, is the imaging modality of choice. In non-jaundiced patients with non-distended biliary tract and suspected bile leak, MRCP should be completed by the injection of a liver-specific contrast agent with biliary excretion to achieve non-invasive biliary tract opacification. In patients with malignancy, CT is preferred due to its high spatial resolution and ability to demonstrate small anastomotic tumor recurrences. CT should also be performed in patients with suspected hepatic artery or portal vein injury in addition to biliary tract injury or to detect distant complications.

Contrast-enhanced MR cholangiography with Gd-EOB-DTPA in patients with liver cirrhosis: visualization of the biliary ducts in comparison with patients with normal liver parenchyma

The purpose of this study was to assess the quality of biliary duct visualization using Gd-EOB-DTPA-enhanced magnetic resonance cholangiography (EOB-MRC) in patients with liver cirrhosis. Forty adult patients with liver cirrhosis (cirrhosis group) and 20 adult individuals with normal liver parenchyma (control group) underwent EOB-MRC using T1-weighted GRE imaging up to 180 min after Gd-EOB-DTPA administration. Two observers assessed the visualization of each biliary structure and the overall anatomical visualization of the biliary tree. Child-Pugh, MELD score and laboratory findings were compared. The grade of visualization for each evaluated biliary structure was statistically different in the two groups (P = 0.004 to <0.001). The overall EOB-MRC quality was rated as sufficient for anatomical visualization of the biliary tree in all individuals of the control group 20 min after Gd-EOB-DTPA application, but in only 16/40 patients (40%) of the cirrhosis group within 30 min after application. Analysis of the ROC curves revealed that the cut-off values, for non-sufficient visualization of the biliary tree 20 min after Gd-EOB-DTPA application, were MELD scores > or =11 and total serum bilirubin levels > or =30 micromol/l. Consecutively, EOB-MRC in patients with liver cirrhosis resulted in a decreased or even non-visualization of the biliary tree in a substantial percentage of patients.

MR imaging of the gallbladder: a pictorial essay

The gallbladder serves as the repository for bile produced in the liver. However, bile within the gallbladder may become supersaturated with cholesterol, leading to crystal precipitation and subsequent gallstone formation. The most common disorders of the gallbladder are related to gallstones and include symptomatic cholelithiasis, acute and chronic cholecystitis, and carcinoma of the gallbladder. Other conditions that can affect the gallbladder include biliary dyskinesia (functional), adenomyomatosis (hyperplastic), and postoperative changes or complications (iatrogenic). Ultrasonography (US) has been the traditional modality for evaluating gallbladder disease, primarily owing to its high sensitivity and specificity for both stone disease and gallbladder inflammation. US performed before and after ingestion of a fatty meal may also be useful for functional evaluation of the gallbladder. However, US is limited by patient body habitus, with degradation of image quality and anatomic detail in obese individuals. With the advent of faster and more efficient imaging techniques, magnetic resonance (MR) imaging has assumed an increasing role as an adjunct modality for gallbladder imaging, primarily in patients who are incompletely assessed with US. MR imaging allows simultaneous anatomic and physiologic assessment of the gallbladder and biliary tract in both initial evaluation of disease and examination of the postoperative patient. This assessment is accomplished chiefly through the use of MR imaging contrast agents excreted preferentially via the biliary system.

MR cholangiopancreatography: 1.5T versus 3T

Soon after its introduction in 1991, MR cholangiopancreatography has become an established diagnostic tool for the evaluation of the pancreaticobiliary ductal system at a field strength of 1.5T. It remains unclear whether MR cholangiopancreatography performed at 3T will benefit from the higher magnetic field strength or whether a field strength of 1.5T should continue to be considered the gold standard for MR cholangiopancreatography. This article reviews the current literature on the benefits and drawbacks of MR cholangiopancreatography at 3T compared with a standard field strength of 1.5T. Field strength-related artifacts that affect MR cholangiopancreatography at 3T also are discussed.

Value of manganese-enhanced T1- and T2-weighted MR cholangiography for differentiating cystic parenchymal lesions from cystic abnormalities which communicate with bile ducts

We present a case report to show how manganese-enhanced T1- and T2-weighted MR cholangiography could differentiate cystic parenchymal lesions from cystic abnormalities which communicate with the bile ducts.

[Contrast-enhanced magnetic resonance cholangiography using gadolinium-EOB-DTPA. Preliminary experience and clinical applications]

Magnetic resonance cholangiopancreaticography (MRCP) with heavily T2-weighted RARE and HASTE sequences has become an important imaging modality for the morphologic evaluation of intra- and extrahepatic bile ducts. However, for the diagnosis of functional biliary disorders, cholangiopancreaticography (ERCP) and endoscopic manometry, two invasive techniques with considerable morbidity and mortality, remain the standard. Biliary scintigraphy, secretin-stimulated MRCP, and secretin-stimulated endoscopic ultrasound have not proven to be sufficient to replace these techniques as they lack diagnostic accuracy and correlate poorly with manometry results. Contrast-enhanced magnetic resonance cholangiography (CE-MRC) uses hepatocyte-selective contrast agents that are eliminated by the biliary system. Therefore, these substances can serve as biliary contrast agents in T1-weighted MR imaging. This method makes a noninvasive functional evaluation of the hepatobiliary system possible. In the present article, our preliminary experience with Gd-EOB-DTPA-enhanced MRC is summarized and potential clinical applications of this method are discussed. Additionally, the article reviews publications evaluating a possible benefit of CE-MRC with other hepatobiliary contrast agents such as mangafodipir trisodium.

[New possibilities to study biliary tree and gallbladder: functional magnetic resonance cholangiography contrast-enhanced with mangafodipir trisodium (Mn DPDP)]

Mangafodipir trisodium (Teslascan) is a hepatobiliary contrast agent that provides noninvasive opacification of the bile ducts. Using this contrast medium combined with a T1-weighted gradient echo enhanced sequence provides functional imaging of the bile ducts. Second-intention MRI was obtained after the usual morphological study of the bile ducts using heavily T2-weighted sequences (SS-FSE Te eff long and SS FSE Te eff short). This method can detect many biliary duct anomalies: biliary leakage in the postoperative context, mapping of bile ducts and the gallbladder in the search for anatomical variants, analysis of biliodigestive or biliobiliary anastomoses, or a dynamic study of bile secretion and excretion. Opacification of the bile ducts has only been possible until now with invasive tests aggravated by a certain co-morbidity rate and their functional study using biliary scintigraphy limited by mediocre spatial resolution. This new possibility provides access not only to morphological imaging, but also to functional imaging with excellent spatial resolution.

Changes over a 20-year period in the clinical presentation of primary sclerosing cholangitis in Sweden

OBJECTIVE

The use of magnetic resonance cholangiopancreaticography (MRCP) as a non-invasive diagnostic tool for primary sclerosing cholangitis (PSC), together with increased clinical awareness of the disease, has led to earlier diagnosis. The aim of this study was to investigate the clinical presentation of PSC including its association with inflammatory bowel disease (IBD) and the development of cholangiocarcinoma at one centre over an observation period of 20 years.

MATERIAL AND METHODS

All patients with well-defined PSC, diagnosed after 16 years of age and treated at Huddinge University Hospital between 1984 and 2004, were included in the study (n=246). PSC and IBD characteristics were retrieved from the patients' medical records. The patients were subdivided according to the date of diagnosis: 185 PSC patients diagnosed before 30 October 1998 were compared with 61 patients diagnosed after that date.

RESULTS

Patients diagnosed after 1998 were significantly older at diagnosis (mean age 41 versus 37 years) and presented fewer symptoms (47% versus 63%) as well as a lower frequency of coexisting IBD (69% versus 82%). In the whole group, women had significantly more symptoms than men, particularly pruritus (p<0.05).

CONCLUSIONS

The clinical spectrum of PSC in Sweden has changed over the past 20 years; today, PSC patients are older at diagnosis and associated IBD is less frequent.

MR contrast agents for liver imaging: what, when, how

The major classes of contrast agents currently used for magnetic resonance (MR) imaging of the liver include extracellular agents (eg, low-molecular-weight gadolinium chelates), reticuloendothelial agents (eg, ferumoxides), hepatobiliary agents (eg, mangafodipir), blood pool agents, and combined agents. Mechanisms of action, dosage, elimination, toxic effects, indications for use, and MR imaging technical considerations vary according to class. Gadolinium chelates are the most widely used. Ferumoxides are a useful adjunct for detection of hepatocellular carcinoma, particularly when used in combination with gadolinium to achieve improved lesion-to-liver contrast over that achievable with gadolinium alone. Mangafodipir is a prototype hepatobiliary agent that is taken up by lesions with functioning hepatocytes. It may be used for MR cholangiography as well as liver imaging. Although mangafodipir is no longer commercially available in the United States, it is currently marketed and used in Europe. Blood pool agents have not yet been approved for human use in the United States. However, a new combined MR contrast agent, gadobenate dimeglumine, recently was approved, and other agents are in various stages of development.

Normal and pathologic features of the postoperative biliary tract at 3D MR cholangiopancreatography and MR imaging

Magnetic resonance (MR) imaging with cholangiopancreatographic sequences plays a critical role in evaluating alterations in the biliary tract after surgical procedures such as cholecystectomy, liver transplantation, hepatic resection, and the creation of a biliary-enteric anastomosis. MR cholangiopancreatography, a rapid, noninvasive, and accurate imaging technique for the assessment of early and late complications of hepatobiliary surgery, usually enables the identification of normal and abnormal postoperative changes. In cases of complete obstruction of the bile duct, MR cholangiopancreatography allows analysis of the biliary tract above and below the level of the obstruction, a capability essential for treatment planning and one that is not provided by either endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography. MR cholangiopancreatography is particularly useful for the evaluation of biliary-enteric anastomoses, for which an endoscopic approach is generally precluded. It also can help detect and localize bile duct strictures and stones and can help accurately classify bile duct injuries. It is useful for detecting bile leaks, although it generally does not directly depict the extravasation of bile. In addition to MR cholangiopancreatography, T1- and T2-weighted MR imaging may be performed to depict extrabiliary soft-tissue structures and abnormalities such as an abscess, tumor recurrence or metastasis, hematoma, or hemobilia. Mangafodipir trisodium-enhanced MR cholangiopancreatography, a recently developed technique that provides a combination of anatomic and functional information, is particularly helpful for documenting bile leaks because it allows a functional evaluation of biliary excretion and may directly depict bile leakage from injured ducts.

Value of adding T1-weighted image to MR cholangiopancreatography for detecting intrahepatic biliary stones

OBJECTIVE

The purpose of this study was to assess the value of adding a T1-weighted image to MR cholangiopancreatography (MRCP) to detect bile duct stones.

MATERIALS AND METHODS

During a 30-month period, 148 patients suspected of having biliary stones and who underwent MRI including MRCP, a fat-suppressed T1-weighted fast low-angle shot (FLASH) sequence, and an axial HASTE sequence were enrolled in this study. The biliary stones were confirmed by ERCP, surgery, and percutaneous transhepatic cholangiography. Of these 148 patients, 73 had extrahepatic stones, 45 had intrahepatic stones, 20 had both extrahepatic and intrahepatic stones, and 10 had no biliary stones. Two separate sets of images, the MRCP set (composed of MRCP and axial HASTE) and the combined interpretion of the MRCP set and the T1-weighted image, were analyzed independently and separately by two observers. The diagnostic accuracy was evaluated using the receiver operating characteristic method. The sensitivity and specificity were also calculated.

RESULTS

For common duct stones, the diagnostic accuracy and the sensitivity of both image sets showed similar values without any significant difference (0.998 [97.8%] for the combined interpretation; 0.988 [97.8%] for observer 1 and 0.995 [96.8%] for observer 2 for the MRCP set). However, for the intrahepatic stones, the diagnostic accuracy (0.993) and the sensitivity (98.5%) of the combined interpretation were significantly higher than those of the MRCP set for the two observers (0.926 [83.8%] for observer 1 and 0.922 [85.3%] for observer 2) (p < 0.05). No significant difference was seen in the specificity of the two image sets for both the intrahepatic and the common duct stones.

CONCLUSION

Combining the axial T1-weighted image with MRCP is valuable for detecting intrahepatic stones.

Bile leaks from the duct of Luschka (subvesical duct): a review

BACKGROUND

Gallstone disease remains the most common disease of the digestive system in Western societies and laparoscopic cholecystectomy one of the most common surgical procedures performed. Bile leaks remain a significant cause of morbidity for patients undergoing this procedure. These occur in 0.2-2% of cases. The bile ducts of Luschka, or subvesical ducts, are small ducts which originate from the right hepatic lobe, course along the gallbladder fossa, and usually drain in the extrahepatic bile ducts. Injuries to these ducts are the second most frequent cause of postcholecystectomy bile leaks.

METHODS

A literature search using MEDLINE's Medical Subject Heading terms was used to identify recent articles. Cross-references from these articles were also used.

RESULTS

Subvesical bile duct leaks can be detected by drip-infusion cholangiography using computed tomography preoperatively, direct visualization or cholangiography intraoperatively, and fistulography, endoscopic retrograde cholangiopancreatography (ERCP), and magnetic resonance cholangiopancreatography with intravenous contrast postoperatively. ERCP is the most common diagnostic method used. Most patients with subvesical duct leaks are symptomatic, and most leaks will be detected postoperatively during the first postoperative week. Drainage of extravasated bile is mandatory in all cases. Reduction of intrabiliary pressure with endoscopic sphincterotomy and stent placement will lead to preferential flow of bile through the papilla, thus permitting subvesical duct injuries to heal. This is the most common treatment modality used. In a minority of patients, relaparoscopy is performed. In such cases, the leaking subvesical duct is visualized directly, and ligation usually is sufficient treatment. Simple drainage is adequate treatment for a small number of asymptomatic patients with low-volume leaks.

CONCLUSIONS

Subvesical duct leaks occur after cholecystectomy regardless of gallbladder pathology or urgency of operation. They have been encountered more frequently in the era of laparoscopic cholecystectomy. Intraoperative cholangiography does not detect all such leaks. Staying close to the gallbladder wall during its removal from the fossa is the only known prophylactic measure. ERCP and stent placement are the most common effective diagnostic and therapeutic methods used. Intraoperative and perioperative adjunctive measures, such as fibrin glue instillation and pharmacologic relaxation of the sphincter of Oddi, can potentially be used in lowering the incidence of subvesical bile leaks.

Gadobenate dimeglumine as an intrabiliary contrast agent: comparison with mangafodipir trisodium with respect to non-dilated biliary tree depiction

OBJECTIVE

To compare the efficacy of Mangafodipir trisodium (Mn-DPDP)-enhanced MR cholangiogrphy (MRC) and Gadobenate dimeglumine (Gd-BOPTA)-enhanced MRC in visualizing a non-dilated biliary system.

MATERIALS AND METHODS

Eighty-eight healthy liver donor candidates underwent contrast-enhanced T1-weighted MRC. Mn-DPDP and Gd-BOPTA was used in 36 and 52 patients, respectively. Two radiologists reviewed the MR images and rated the visualization of the common duct, the right and left hepatic ducts, and the second-order branches using a 4-point scale. The contrast-to-noise ratio (CNR) of the common duct to the liver in the two groups was also compared.

RESULTS

Mn-DPDP MRC and Gd-BOPTA MRC both showed similar visualization grades in the common duct (p=.380, Mann-Whitney U test). In the case of the proximal bile ducts, the median visualization grade was significantly higher with Gd-BOPTA MRC than with Mn-DPDP MRC (right hepatic duct: p=0.016, left hepatic duct: p=0.014, right secondary order branches: p=0.006, left secondary order branches, p=0.003). The common duct-to-liver CNR of the Gd-BOPTA MRC group was significantly higher (38.90+/-24.50) than that of the Mn-DPDP MRC group (24.14+/-17.98) (p=.003, Student's t test).

CONCLUSION

Gd-BOPTA, as a biliary contrast agent, is a potential substitute for Mn-DPDP.

Intérêt de l’IRM avec perfusion de mangafodipir trisodium dans la détection des fuites biliaires

PURPOSE

To assess the value of contrast-enhanced magnetic resonance cholangiography with Teslascan perfusion for the detection and localization of trauma-induced and postoperative bile leaks.

MATERIALS AND METHODS

Between October 2002 and December 2004, 7 patients with suspected bile duct leaks after trauma (n = 2) or surgery (n = 5) requiring morphological evaluation were included. MRI examination included single shot fast spin- echo T2 weighted and gradient echo T1 weighted images prior to and 112 minutes in average after IV administration of mangafodipir trisodium. The results of contrast enhanced MR cholangiography were correlated to surgery (n = 3), clinical course (n = 3) and percutaneous drainage (n = 1).

RESULTS

Mangafodipir trisodium-enhanced imaging showed extravasated Teslascan in collections in 6 patients (86%) whereas the combination of T2 weighted images and mangafodipir trisodium enhanced images revealed biliary collections in 7 patients (100%). The fistula between bile duct and collection was visualized in 4 patients (57%) before mangafodipir trisodium perfusion and in 3 patients (43%) after injection. In one patient the fistula was visible only after injection. Combination of both pre- and post injection MR correctly depicted the origin of bile leak in 5 cases (71%).

CONCLUSION

Mangafodipir trisodium-enhanced magnetic resonance cholangiography is a non invasive technique that can successfully detect the presence of bile duct leaks. The combination of T2 weighted MR cholangiography and mangafodipir trisodium-enhanced T1 weighted MR cholangiography increases the sensitivity in detection and localization of the site of bile leak.

Bile duct leaks after laparoscopic cholecystectomy: value of contrast-enhanced MRCP

BACKGROUND

We assessed the role of mangafodipir-enhanced magnetic resonance (MR) cholangiography in the detection and location of bile duct leaks after laparoscopic cholecystectomy.

METHODS

In a prospective study, 34 patients with clinical suspicion of bile duct leak after laparoscopic cholecystectomy underwent MR imaging. Our protocol included conventional heavily T2-weighted MR cholangiography and three-dimensional T1-weighted MR cholangiography after an intravenous bolus injection of mangafodipir trisodium. All studies were performed on a 1.5-T or 1-T scanner. Contrast-enhanced MR cholangiograms were evaluated for the presence and location of bile duct leaks. Correlation was obtained in all cases with surgery (n=15), endoscopic retrograde cholangiography (n=5), percutaneous drainage (n=5), and clinical follow-up (n=9).

RESULTS

In 20 of 34 patients, bile duct leakage was proved by surgery, endoscopic retrograde cholangiography, or drainage. Contrast enhancement displayed the leakage in 19 of 20 patients and ruled out leaks in the other 14 patients (95% sensitivity, 100% specificity). The leak site was depicted in 14 patients and contrast-enhanced MR cholangiography successfully located the origin of the leak in 11 patients.

CONCLUSIONS

Contrast-enhanced MR cholangiography with intravenous mangafodipir trisodium can accurately diagnose the presence and location of bile duct leaks in patients who have undergone laparoscopic cholecystectomy.

MR cholangiography with manganese dipyridoxyl diphosphate in the evaluation of biliary-enteric anastomoses: preliminary experience

OBJECTIVE

The purpose of our study was to assess the usefulness of manganese dipyridoxyl diphosphate (Mn-DPDP)-enhanced T1-weighted MR cholangiography for evaluating patients with biliary-enteric anastomoses.

CONCLUSION

Mn-DPDP-enhanced T1-weighted MR cholangiography may provide useful functional information and may aid in the assessment of the patency of biliary-enteric anastomoses.

MR Imaging of the Gallbladder and Biliary System

MR imaging is an established technique for the diagnosis of a spectrum of biliary and gallbladder pathologies and continues to improve with the advent of technologic advances, including new contrast agents and new sequences that are capable of improving upon the contrast resolution and signal-to-noise that are afforded by conventional MR imaging. These improvements already have shown promise for the increasing role of MRC as the initial modality in assessing living liver donors and evaluating post-operative hepato-biliary complications. Improved spatial resolution and the added functional or physiologic information afforded by MR imaging promise ever expanding clinical applicability and usefulness.

Biliary Atresia: Feasibility of Mangafodipir Trisodium–enhanced MR Cholangiography for Evaluation

The study was approved by the institutional review board, and informed consent was obtained from the patients' parents. Twenty-three consecutive infants suspected of having biliary atresia (BA) were prospectively examined by using mangafodipir trisodium (Mn-DPDP)-enhanced magnetic resonance (MR) cholangiography. Sequential T1-weighted spoiled gradient-echo MR cholangiograms were obtained 1, 2, and 3 hours after intravenous administration of Mn-DPDP. The possibility of BA was excluded if bowel excretion of contrast material was noted at contrast material-enhanced MR cholangiography. The diagnostic specificity and accuracy of contrast-enhanced MR cholangiography were compared with those of conventional MR cholangiography, technetium 99m Tc ((99m)Tc)-disofenin (DISIDA) scintigraphy, and the triangular cord sign at ultrasonography (US). MR cholangiography was used to accurately distinguish four cases of BA from 19 cases of other cholestatic liver diseases, without false-positive results. Conventional MR cholangiography, (99m)Tc-DISIDA scintigraphy, and the triangular cord sign at US respectively yielded false-positive results of 42% (eight of 19 infants), 35% (six of 17 infants), and 11% (two of 19 infants) in patients without BA. Mn-DPDP-enhanced MR cholangiography appears to be a promising modality for early diagnosis of BA as the cause of neonatal cholestasis.

Early biliary complications of laparoscopic cholecystectomy: evaluation on T2-weighted MR cholangiography in conjunction with mangafodipir trisodium-enhanced 3D T1-weighted MR cholangiography

OBJECTIVE

Our aim was to assess preliminary experience with combined conventional T2-weighted and mangafodipir trisodium (MnDPDP)-enhanced T1-weighted MR cholangiography in evaluating early biliary complications of laparoscopic cholecystectomy.

SUBJECTS AND METHODS

Conventional heavily T2-weighted MR cholangiography with MnDPDP-enhanced T1-weighted MR cholangiography and ERCP were performed in seven patients with high clinical suspicion of biliary complications after laparoscopic cholecystectomy. The final diagnoses of complications were classified according to the presence and degree of bile duct injury, bile leakage, and retained stones.

RESULTS

The diagnoses on MR cholangiography were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 3), partial strictures of the common bile duct with bile leakage (n = 1), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). The final diagnoses at surgery (n = 2) and ERCP (n = 5) were as follows: complete transection and occlusion of the common bile duct with bile leakage (n = 2), partial strictures of the common bile duct with bile leakage (n = 2), cystic duct leakage (n = 1), partial ligation of an aberrant right hepatic duct (n = 1), and hemorrhage without biliary complication (n = 1). MR cholangiography accurately yielded the same findings as the final diagnoses, except in one case with partial stricture of the bile duct with bile leakage (overdiagnosed as complete occlusion on MR cholangiography).

CONCLUSION

Combined conventional T2-weighted and MnDPDP-enhanced T1-weighted MR cholangiography may eliminate the use of other studies for the imaging of biliary complications after cholecystectomy if this preliminary data can be verified in a larger study.

Value of MR Cholangiography in Patients with Iatrogenic Bile Duct Injury After Cholecystectomy

OBJECTIVE

Our aim was to determine the diagnostic role of MR cholangiography in the evaluation of iatrogenic bile duct injuries after cholecystectomy.

SUBJECTS AND METHODS

Nineteen patients (14 women and five men; mean age, 47 years; age range, 24-75 years) with suspected bile duct injury as a result of laparoscopic cholecystectomy (17 patients) and open cholecystectomy (two patients) underwent MR cholangiography. MR images were evaluated for bile duct discontinuity, presence or absence of biliary dilation, stricture, excision injury, free fluid, and collections. Bile duct excision and stricture were classified according to the Bismuth classification. Final diagnosis was made on the basis of findings at surgery in 15 patients, on percutaneous transhepatic cholangiography (PTC) in one patient, and on endoscopic retrograde cholangiography (ERC) and at clinical follow-up until hospital discharge in the remaining three patients.

RESULTS

In 16 patients, injury of the bile duct was observed. Two patients had Bismuth type I injury; one patient, type II injury; 11 patients, type III injury; and one patient each, type IV and V injuries. Three patients showed findings suggestive of leakage from the cystic duct remnant, which were confirmed on ERC.

CONCLUSION

MR cholangiography is an accurate diagnostic technique in the identification of postoperative bile duct injuries. This technique allows exploration above and below the level of obstruction, a resource provided by neither ERC nor PTC, and allows the accurate classification of these injuries, which is essential for treatment planning.

Contrast-enhanced magnetic resonance cholangiography using mangafodipir compared with standard T2W MRC sequences: a pictorial essay

Mangafodipir, a manganese-containing hepatobiliary contrast agent, is excreted in bile. We review the principles and practice of a contrast-enhanced MRC technique using mangafodipir and compare it with standard T2-weighted magnetic resonance cholangiography (MRC) sequences. Potential applications include the evaluation of leaks and strictures; the assessment of drainage in normal, surgically by-passed, stented and obstructed biliary systems; the diagnosis of cholecystitis; and the evaluation of normal and variant biliary anatomy.

Increased manganese concentration in the liver after oral intake

RATIONALE AND OBJECTIVES

Manganese is a well-known liver-specific agent used in magnetic resonance imaging. For this purpose, manganese is now administered intravenously. In theory it should be possible to increase the gastrointestinal uptake of manganese through the use of nutritional products as promoters. Such an agent has now been formulated. As part of a primary pharmacologic investigation, the uptake of manganese in the kidney, heart, and liver was studied.

MATERIALS AND METHODS

One hundred two female Sprague Dawley rats fasted for 18 hours before the agent (CMC-001) was given orally by gavage. One hundred micromol/kg BW was given to all rats except six, who served as controls. Various concentrations of the promoters (vitamin D3 and the amino acid alanine) were also given. Three hours after administration the rats were killed and the heart, the liver and kidneys were removed. The manganese content was determined by atomic absorption.

RESULTS

No systematic increased concentration of manganese was found in either the kidneys or the heart; whereas the manganese content of the liver (approximately 100%) increased significantly compared with the controls and the group receiving pure manganese. No side effects were observed.

CONCLUSION

It is possible to increase the gastrointestinal uptake of manganese in fasting rats and thereby increase the concentration in the liver.

Magnetic Resonance Cholangiography With Mangafodipir Trisodium (Teslascan) to Evaluate Bile Duct Leaks After T-Tube Removal in Liver Transplantation

Liver transplant patients who present with abdominal pain after removal of the T-tube can be initially evaluated by contrast-enhanced magnetic resonance cholangiography (CEMRC) instead of abdominal computed tomography and hepatobiliary scintigraphy. In this article, 3 liver transplant patients who were evaluated by CEMRC after removal of the T-tube. CEMRC successfully identified the presence, location and extent of bile duct leaks, and can be performed as a diagnostic study in patients with suspected bile duct leaks.

Diagnosing biliary complications of orthotopic liver transplantation with mangafodipir trisodium-enhanced MR cholangiography: comparison with conventional MR cholangiography

OBJECTIVE

This study was designed to determine whether the addition of mangafodipir trisodium-enhanced MRI could improve the image quality, visualization of ductal structures, and diagnostic confidence provided by conventional T2-based MR cholangiography (MRC) in patients with suspected biliary complications after orthotopic liver transplantation. SUBJECTS AND METHODS. Our study group consisted of 25 consecutive patients who were referred for MR evaluation of clinically suspected biliary complications after orthotopic liver transplantation. Conventional MRC in the axial and coronal planes was performed in each patient, followed by fat-suppressed volumetric gradient-echo imaging in the same planes both before and after the IV administration of mangafodipir trisodium. Imaging was performed in all patients until the contrast agent was seen in the bowel. Images were then graded for quality, visualization of bile ducts and anastomoses, presence of significant stricture or leak, and level of diagnostic confidence.

RESULTS

Mangafodipir trisodium-enhanced MRC tended to outperform conventional MRC in overall image quality and extrahepatic duct visualization; it was also more effective in delineating biliary anastomoses, and the difference was statistically significant (p < 0.001). All 25 enhanced examinations were considered diagnostic. Diagnostic confidence was scored as poor or lacking in 14 of the conventional MRC examinations for biliary stenosis and in 12 examinations for biliary leak.

CONCLUSION

Enhancement with mangafodipir trisodium improves the performance of MRC for the detection and exclusion of biliary abnormalities after orthotopic liver transplantation. Future investigations should compare the performance of mangafodipir trisodium-enhanced MRC with the performance of more invasive techniques.

Evaluation of Living Liver Transplant Donors: Method for Precise Anatomic Definition by Using a Dedicated Contrast-enhanced MR Imaging Protocol

Liver transplantation from a living donor involves removal of part of the donor liver in a fashion that does not endanger its vascular supply or metabolic function. The radiologist plays an important role in evaluation of the living donor to define the conditions under which graft donation is contraindicated and to identify anatomic variations that may alter the surgical approach. In the past, diagnostic work-up of the donor involved costly and invasive tests. Currently, dynamic contrast material-enhanced computed tomography and magnetic resonance (MR) imaging are the imaging tests performed, each of which has advantages and limitations. MR imaging performed with liver-specific and extravascular contrast agents may be used as a single imaging test for comprehensive noninvasive evaluation of living liver transplant donors. MR imaging provides valuable information about variations in the vascular and biliary anatomy and allows evaluation of the hepatic parenchyma for diffuse or focal abnormalities.

Mangafodipir-enhanced magnetic resonance cholangiography for the diagnosis of bile duct leaks

BACKGROUND

The purpose of this prospective study was to assess the value of contrast-enhanced magnetic resonance cholangiography with mangafodipir trisodium perfusion for detection and localization of trauma-induced and postoperative bile duct leaks.

METHODS

Eleven patients with suspected bile duct leaks after trauma (n=5) or surgery (n=6) were included. Patients with suspected leaks after cholecystectomy were excluded. All patients underwent contrast-enhanced magnetic resonance cholangiography with two-dimensional axial and three-dimensional coronal gradient-echo images acquired 1 to 3 hours after intravenous administration of mangafodipir trisodium perfusion. Contrast-enhanced magnetic resonance cholangiography findings were correlated with direct cholangiography obtained in all patients, including endoscopic retrograde (n=7) and percutaneous transhepatic cholangiography (n=4).

RESULTS

Biliary tract enhancement was identified in all patients on contrast-enhanced magnetic resonance cholangiography. Peritoneal cavity fluid and bile collections that contained extravasated mangafodipir trisodium (increased signal intensity on gradient-echo sequences) were demonstrated in 6 patients. Direct cholangiography confirmed the presence of bile duct leaks in these 6 patients and the absence of bile duct leaks in 5 patients. There was no false-negative or false-positive contrast-enhanced magnetic resonance cholangiography.

CONCLUSIONS

Mangafodipir-enhanced magnetic resonance cholangiography is a noninvasive technique that can provide functional biliary information with excellent depiction of bile duct leaks.

Oral manganese for liver imaging at three different field strengths

RATIONALE AND OBJECTIVES

To study the magnetic resonance imaging signal intensity of the liver and gall bladder before and after ingestion of a new oral manganese containing contrast medium at three different field strengths.

MATERIALS AND METHODS

Twelve healthy male volunteers (mean age, 24.9 years; range, 20-39 years) underwent abdominal magnetic resonance imaging (T(2)W COR, T(1)W COR, T(1)W TRA) at 0.23 T, 0.6 T, and 1.5 T before and after the contrast administration. The duration of fasting was identical before the two studies. Volunteers were randomized into two equal groups (n = 6) to ingest either half or full strength CMC-001 providing either 0.8 or 1.6.g MnCl(2) plus absorption promoters. The CMC-001 dose was dissolved in 400 mL water and ingested 2.5 hours before imaging. The resulting images were evaluated with regard to visualization of the liver and the gall bladder by three radiologists. The signal intensity of the liver was also measured. Blood and urine samples were collected before and after ingestion of CMC-001.

RESULTS

The intake of CMC-001 caused a significant increase in the signal intensity of the liver at all three field strengths and at both dosages (up to 90%) on the T(1)W images. The internal structure of the liver was significantly better delineated. The bile in gall bladder was bright after ingestion of the low dose, but dark after the full dose. On the T(2)W images, CMC-001 lowered the signal intensity of liver with up to 30%. CMC-001 had a slight metallic taste, but of no importance according to the volunteers. No systematic adverse reactions caused by the contrast medium were registered. No changes in the blood levels of various routine parameters were measured.

CONCLUSION

It is possible to increase the signal intensity of the liver significantly by oral intake of essential nutritional elements including manganese. The imaging window is more than 2 hours.