Visualization of the biliary tract using gadobenate dimeglumine: preliminary findings. J Comput Assist Tomogr. 2008;32:54-60. [PMID: 18303288 DOI: 10.1097/rct.0b013e3180616b87]

[Passive and active magnetic resonance cholangiopancreatography : Technique, indications, and typical anatomy]

CLINICAL/METHODICAL ISSUE

In daily routine, every radiologist is confronted with a variety of questions concerning the biliary tract and pancreatic system.

STANDARD RADIOLOGICAL METHODS

Today, besides sonography, magnetic resonance cholangiopancreatography (MRCP) is considered the method of choice in the investigation of many disorders of the hepatobiliary and pancreatic system and is commonly preferred over invasive ERCP in a mere diagnostic setting.

METHODICAL INNOVATIONS

Since its introduction in 1991, MRCP has constantly evolved. Major innovations have been the reduction of acquisition time by using fast spin echo (FSE) sequences, the use of respiratory gating and contrast-enhanced imaging of the bile ducts with hepatobiliary-specific MRI contrast agents.

PERFORMANCE

Many diagnoses may already be made with noncontrast enhanced images. By supplemental administration of a hepatobiliary-specific contrast agent, it is also possible to evaluate the flow dynamics of the bile. This is of additional value especially in patients who underwent surgery of the biliodigestive system or endoscopic interventions.

ACHIEVEMENTS

Aside from robustness and reproducibility, a major advantage of this technique is the modular design of imaging protocols, which can easily be adapted to the clinical question.

PRACTICAL RECOMMENDATIONS

MRCP is a reliable and low-risk imaging method for primary diagnosis and follow-up of biliary and pancreatic pathologies.

Detection and characterization of traumatic bile leaks using Gd-EOB-DTPA enhanced magnetic resonance cholangiography

Expanding bile leaks after blunt liver trauma require more aggressive treatment than contained bile leaks. In this retrospective study approved by institution review board, we analyzed if non-invasive contrast-enhanced magnetic resonance cholangiography (CEMRC) using hepatocyte-specific contrast agent (gadoxetic acid disodium) could detect and characterize traumatic bile leaks. Between March 2012 and December 2014, written informed consents from 22 included patients (17 men, 5 women) with a median age of 24.5 years (IQR 21.8, 36.0 years) were obtained. Biliary tree visualization and bile leak detection on CEMRC acquired at 10, 20, 30, 90 minutes time points were independently graded by three radiologists on a 5-point Likert scale. Intraclass Correlation (ICC) was computed as estimates of interrater reliability. Accuracy was measured by area under receiver operating characteristic curves (AUROC). Biliary tree visualization was the best on CEMRC at 90 minutes (score 4.30) with excellent inter-rater reliability (ICC = 0.930). Of 22 CEMRC, 15 had bile leak (8 expanding, 7 contained). The largest AUROC of bile leak detection by three radiologists were 0.824, 0.914, 0.929 respectively on CEMRC at 90 minutes with ICC of 0.816. In conclusion, bile leaks of blunt liver trauma can be accurately detected and characterized on CEMRC.

Peritoneal and pleural fluids may appear hyperintense on hepatobiliary phase using hepatobiliary MR contrast agents

AIM

To describe the effect of hepatobiliary-specific MR imaging contrast agent (HBCA) administration on the signal intensity of peritoneal and pleural fluid effusions on T1-weighted MR images.

MATERIALS AND METHODS

From October 2015 to May 2016 139 patients (mean 60±10 years old, 69 % males) with peritoneal or pleural effusions without biliary leakage who underwent HBCA-MRI (Gd-BOPTA or Gd-EOB-DTPA) at 1.5T and 3T were included from two centres. The fluid signal intensity was classified as hypo/iso/hyperintense before/after HBCA administration. The relative signal enhancement (RE) was calculated.

RESULTS

On hepatobiliary phase (HBP), peritoneal fluids appeared hyper/isointense in 88-100 % and pleural effusions in 100 % of the patients following Gd-BOPTA administration. All fluids remained hypointense following Gd-EOB-DTPA. The signal intensity of fluids increased with both HBCA but RE was significantly higher following Gd-BOPTA (p=0.002 to <0.001). RE was correlated with HBP acquisition time-point (r=0.42, p<0.001 and r=0.50, p=0.033 for peritoneal and pleural fluids).

CONCLUSION

The signal intensity of pleural and peritoneal fluids progressively increases following HBCA administration in the absence of biliary leakage. Due to its later hepatobiliary phase, this is more pronounced after Gd-BOPTA injection, leading to fluid hyperintensity that is not observed after Gd-EOB-DTPA injection.

KEY POINTS

• Fluids appear hyper/isointense on HBP in most patients after Gd-BOPTA injection. • Fluids remain hypointense on HBP after Gd-EOB-DTPA injection. • RE of fluids increases with time after liver-specific Gd injection. • RE of fluids is higher in patients with chronic liver disease.

Gadoxetic acid: pearls and pitfalls

Gadoxetic acid is a hepatocyte-specific magnetic resonance imaging contrast agent with the ability to detect and characterize focal liver lesions and provide structural and functional information about the hepatobiliary system. Knowledge of the pharmacokinetics of gadoxetic acid is paramount to understanding imaging protocol and lesion appearance and facilitates identification and avoidance of undesired effects with use of this intravenous contrast agent. This article reviews the utility of gadoxetic acid in liver and biliary imaging, with emphasis on the hepatobiliary phase.

Contrast-enhanced MR cholangiography with Gd-EOB-DTPA for preoperative biliary mapping: correlation with intraoperative cholangiography

BACKGROUND

Gd-EOB-DTPA-enhanced magnetic resonance (MR) could be used for preoperative evaluation of bile duct anatomy in addition to conventional information of focal hepatic lesions.

PURPOSE

To evaluate accuracy of contrast-enhanced MR cholangiography (CE MRC) reconstructed from Gd-EOB-DTPA-enhanced MR images for depicting biliary anatomy with intraoperative cholangiography.

MATERIAL AND METHODS

We retrospectively identified 71 patients who underwent both preoperative Gd-EOB-DTPA-enhanced MR imaging (MRI) and intraoperative cholangiography for hepatic resections. Two readers independently analyzed biliary anatomy using CE MRC reconstructed from transverse and coronal images separately in 4 weeks. The accuracy and diagnostic confidence were evaluated in correlation with intraoperative cholangiography. The accuracy and confidence score (3-point scale) were compared on CE MRCs from transverse versus coronal images.

RESULTS

CE MRCs correctly depicted biliary anatomy in 91.5% and 88.7% with coronal images and in 81.7% and 73.2% with transverse images for readers 1 and 2, respectively. CE MRCs from coronal images tended to show greater accuracy (P = 0.12 and 0.01, for readers 1 and 2) and higher confidence score (P = 0.11 and P = 0.04, for readers 1 and 2) than those from transverse images.

CONCLUSION

Accurate preoperative biliary mapping can be achieved on CE MRC reconstructed from Gd-EOB-DTPA-enhanced MR images. The diagnostic performance was better on CE MRC reconstructed from coronal than those from transverse images.

Magnetic resonance cholangiography in the assessment and management of biliary complications after OLT

Despite advances in patient and graft management, biliary complications (BC) still represent a challenge both in the early and delayed period after orthotopic liver transplantation (OLT). Because of unspecific clinical presentation, imaging is often mandatory in order to diagnose BC. Among imaging modalities, magnetic resonance cholangiography (MRC) has gained widespread acceptance as a tool to represent the reconstructed biliary tree noninvasively, using both the conventional technique (based on heavily T2-weighted sequences) and contrast-enhanced MRC (based on the acquisition of T1-weighted sequences after the administration of hepatobiliary contrast agents). On this basis, MRC is generally indicated to: (1) avoid unnecessary procedures of direct cholangiography in patients with a negative examination and/or identify alternative complications; and (2) provide a road map for interventional procedures or surgery. As illustrated in the review, MRC is accurate in the diagnosis of different types of biliary complications, including anastomotic strictures, non-anastomotic strictures, leakage and stones.

Diagnostic workup of primary sclerosing cholangitis: the benefit of adding gadoxetic acid-enhanced T1-weighted magnetic resonance cholangiography to conventional T2-weighted magnetic resonance cholangiography

AIM

To evaluate the value of gadoxetic acid-enhanced T1-weighted (T1W) magnetic resonance cholangiography (MRC) versus conventional T2-weighted (T2W) MRC compared to endoscopic retrograde cholangiopancreatography (ERCP) in patients with primary sclerosing cholangitis (PSC).

MATERIALS AND METHODS

Based on T1W MRC, PSC patients were classified into a regular (RG) and a delayed (DG) excreting group, with an absence of gadoxetic acid in the common bile duct at 20 min. Beading, pruning, and gradation of central bile duct stenosis, evaluated by T1W and T2W MRC, were compared to ERCP. Liver parenchymal enhancement was measured in both study groups and compared to a reference group (n = 20) without a history of liver disease. Two readers performed all measurements.

RESULTS

Based on beading and pruning of the peripheral bile ducts, sensitivities, specificities, and accuracies for reader 1 were 0.17/0.43, 0/0.17, and 0.15/0.31 for T1W MRC, and 0.83/0.86, 1/0.83, and 0.85/0.85 for T2W MRC (p = 0.004). For reader 2 sensitivities, specificities, and accuracies were 0.25/0.57, 0/0.33, and 0.23/0.46 for T1W MRC, and 0.92/1, 1/0.83, and 0.92/0.92 for T2W MRC (p = 0.012). Compared to ERCP, central bile duct stenoses were significantly overestimated (p < 0.001) by T2W MRC. A significantly lower parenchymal enhancement was found in the DG (n = 7) compared to the RG (n = 13), and compared to the reference group (p < 0.001).

CONCLUSION

The combined performance of T2W and T1W MRC may provide a comprehensive imaging workup of PSC, including morphological and functional information resulting in optimal management.

The efficiency of Gd-EOB-DTPA-enhanced magnetic resonance cholangiography in living donor liver transplantation: a preliminary study

The aim of this study was to evaluate utility of gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance cholangiography (MRC) for the detection of biliary complications after living donor liver transplantation (LDLT). A total of 18 patients with suspected biliary complications underwent MRC. T2-weighted MRC and contrast-enhanced MRC (CE-MRC) were used to identify the biliary complications. MRC included routine breath-hold T2-weighted MRC using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences and Gd-EOB-DTPA-enhanced MRC T1-weighted volumetric interpolated breath-hold examination (VIBE) sequences. Before confirming the biliary complications, one observer reviewed the MRC images and the CE-MRC images separately. The verification procedures and MRC findings were compared, and the sensitivity, specificity, and accuracy of both techniques were calculated for the identification of biliary complications. The observer found six of seven biliary complications using CE-MRC. The sensitivity was 85.7% and the accuracy was 94.4%. Using MRC alone, sensitivity was 57.1% and accuracy was 55.5%. The accuracy of Gd-EOB-DTPA-enhanced MRC was superior to MRC in locating biliary leaks (p < 0.05). The usage of Gd-EOB-DTPA-enhanced MRC yields information that complements the MRC findings that improve the identification of biliary complications. We recommend the use of MRC in addition to Gd-EOB-DTPA-enhanced MRC to increase the preoperative accuracy when assessing the biliary complications after LDLT.

MRI assessment of biliary ductal obstruction: is there added value of T1-weighted gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced MR cholangiography?

OBJECTIVE

The goal of the present study was to determine the added value of gadolium-ethoxybenzyl-diethylenetriamine pentaacetic acid (gadoxetate disodium)-enhanced magnetic resonance cholangiography (MRC) to standard liver MRI including T2-weighted MRCP in assessment of biliary ductal obstruction.

MATERIALS AND METHODS

Thirty-eight patients (mean age, 48.1 ± 16.7 years) (40 total examinations) who underwent liver MRI (including T2-weighted MRCP and gadoxetate disodium-enhanced MRC) for suspicion of biliary disease were included in this institutional review board-approved, HIPAA-compliant retrospective study. Three blinded radiologists first evaluated MR images without gadoxetate disodium-enhanced MRC for presence and significance of biliary obstruction, underlying cause for obstruction, and confidence in final diagnosis. After inclusion of gadoxetate disodium-enhanced MRC, readers again determined presence and significance of biliary obstruction and confidence in final diagnosis. Reference standard was established using MRI along with ERCP, percutaneous transhepatic cholangiography, intraoperative cholangiography, or a combination thereof.

RESULTS

Overall sensitivity across all readers in diagnosing significance of obstruction was 60% without gadoxetate disodium-enhanced MRC and 91% with gadoxetate disodium- enhanced MRC (p < 0.001). Across all readers, assessment of significance of obstruction was changed when adding gadoxetate disodium-enhanced MRC in 40 of 120 cases (33%); significance of obstruction was correctly changed in 35 of 40 cases (87.5%). Biliary obstruction was graded of unknown significance in 27 of 120 cases (22.5%) across all readers when gadoxetate disodium-enhanced MRC was not reviewed. Significance of biliary obstruction was classified correctly after adding gadoxetate disodium-enhanced MRC in 25 of these 27 cases (93%). Confidence in final diagnosis was significantly higher with addition of gadoxetate di-sodium-enhanced MRC for two of three readers (p < 0.003).

CONCLUSION

Addition of gadoxetate disodium-enhanced MRC to liver MRI significantly improves sensitivity in assessing significance of biliary obstruction and can improve reader confidence in establishing a final diagnosis. This added information could have a substantial impact in the determination of the most appropriate therapeutic options.

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.

Functional MR cholangiography of the cystic duct and sphincter of Oddi using gadoxetate disodium: is a 30-minute delay long enough?

PURPOSE

To determine if excreted contrast is consistently visualized in the gallbladder and duodenum after a 30-minute delay using gadoxetate disodium-enhanced MRI in patients without hepatobiliary disease.

MATERIALS AND METHODS

Twenty-two patients without evidence of liver or biliary disease underwent gadoxetate disodium-enhanced magnetic resonance imaging (MRI) from February 17, 2009 through October 3, 2011. The mean age was 45 years (range 25-72). T1-weighted hepatobiliary phase images at 5, 10, 20, and 30 minutes after contrast injection were reviewed in consensus by two radiologists to determine the delay at which enhancement of the gallbladder and duodenum first occurred.

RESULTS

Thirteen of 22 (59.1%) patients demonstrated duodenal filling by 20 minutes and 16/22 (72.7%) filled by 30 minutes. The mean time to duodenal enhancement was 19.9 minutes (range 11.4-30.2 min). Seventeen of 22 (77.3%) patients demonstrated gallbladder filling by 20 minutes and 21/22 (95.5%) filled by 30 minutes. The mean time to gallbladder enhancement was 16.5 minutes (range 4.4-30.2 min).

CONCLUSION

A significant number of normal patients do not show duodenal filling by 30 minutes, while the majority fill the gallbladder by 30 minutes using functional MR cholangiography (fMRC) with gadoxetate disodium. These findings will guide fMRC protocol design for patients with suspected acute cholecystitis and sphincter of Oddi dysfunction.

Hepatobiliary MR imaging with gadolinium-based contrast agents

The advent of gadolinium-based "hepatobiliary" contrast agents offers new opportunities for diagnostic magnetic resonance imaging (MRI) and has triggered great interest for innovative imaging approaches to the liver and bile ducts. In this review article we discuss the imaging properties of the two gadolinium-based hepatobiliary contrast agents currently available in the U.S., gadobenate dimeglumine and gadoxetic acid, as well as important pharmacokinetic differences that affect their diagnostic performance. We review potential applications, protocol optimization strategies, as well as diagnostic pitfalls. A variety of illustrative case examples will be used to demonstrate the role of these agents in detection and characterization of liver lesions as well as for imaging the biliary system. Changes in MR protocols geared toward optimizing workflow and imaging quality are also discussed. It is our aim that the information provided in this article will facilitate the optimal utilization of these agents and will stimulate the reader's pursuit of new applications for future benefit.

MR evaluation of biliary-enteric anastomotic stricture: does contrast-enhanced T1W MRC provide additional information?

BACKGROUND AND OBJECTIVE

To compare T2W-MRCP and T1W contrast-enhanced MRC (CE-MRC) using Gd-BOPTA for evaluation of biliary-enteric anastomotic (BEA) stricture.

PATIENTS AND METHODS

Twenty-one patients who were suspected to have BEA stricture underwent T2W-MRCP and CE-MRC on a 1.5T scanner. Images were evaluated for evidence of anastomotic stricture. Composite gold standard was used including the findings on percutaneous transhepatic cholangiogram or percutaneous transhepatic biliary dilatation, surgery, alkaline phosphatase level and clinical follow-up.

RESULTS

The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of T2W-MRCP for the diagnosis of anastomotic stricture were 94.4%, 80%, 94.4% and 80% respectively. On CE-MRC, biliary excretion was seen in only 60.87% anastomoses and only these were taken for analysis. The sensitivity, specificity, PPV and NPV of CE-MRC for the diagnosis of anastomotic stricture were 40%, 75%, 80% and 33.3%. The combined evaluation of T2W-MRCP and CE-MRC showed sensitivity, specificity, PPV and NPV of 83.3%, 80%, 93.8% and 57.1%.

CONCLUSION

At present, T2W-MRCP is still the diagnostic modality of choice in the evaluation of patients with BEA stricture and the usage of Gd-BOPTA enhanced MRC is inappropriate in this setting.

Gd-BOPTA-enhanced MR cholangiography findings in gall bladder perforation

Gall bladder perforation is a rare condition which is associated with significant mortality and morbidity. Here, we report a case of spontaneous gall bladder perforation following acute calculous cholecystitis with pericholecystic abscess identified on Gd-BOPTA-enhanced MR cholangiography (MRC) prior to laparoscopic surgery. The gall bladder perforation was confirmed via surgery with unremarkable recovery. To the best of our knowledge, this is the first report of Gd-BOPTA-enhanced MRC for this purpose.

Confident diagnosis of bronchobiliary fistula using contrast-enhanced magnetic resonance cholangiography

We report the utility of contrast-enhanced magnetic resonance cholangiography (MRC) using gadoxetic acid (Gd-EOB-DTPA) in the diagnosis of bronchobiliary fistula associated with liver hydatid cyst. Contrast-enhanced MRC clearly delineated the leakage of contrast agent from the biliary duct and its communication with the bronchial tree. Providing functional information about physiologic or pathologic biliary flow in addition to the display of biliary anatomy, contrast-enhanced MRC stands as a robust technique in confidently detecting bronchobiliary fistula and bile leaks.

Biliary MR imaging with Gd-EOB-DTPA and its clinical applications

The hepatocyte-specific contrast agent gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) was developed to improve the detection and characterization of focal liver lesions at magnetic resonance (MR) imaging. Approximately 50% of the injected dose is taken up into the functional hepatocyte and is excreted via the biliary system. Because of this property, Gd-EOB-DTPA has the potential to be a biliary contrast agent. When combined with T2-weighted MR cholangiography, Gd-EOB-DTPA-enhanced MR imaging can allow morphologic and functional assessment of the biliary system. Gd-EOB-DTPA-enhanced MR cholangiography could be effective in evaluation of biliary anatomy, differentiation of biliary from extrabiliary lesions, diagnosis of cholecystitis, assessment of bile duct obstruction, detection of bile duct injury including leakage and stricture, evaluation of biliary-enteric anastomoses, postprocedure evaluation, differentiation of biloma from other pathologic conditions, and evaluation of sphincter of Oddi dysfunction. However, the clinical applications of this imaging technique have not yet been fully explored, and further investigations are needed to determine the utility of Gd-EOB-DTPA-enhanced MR cholangiography in a clinical setting.

Initial experience on utility of gadobenate dimeglumine (Gd-BOPTA) enhanced T1-weighted MR cholangiography in diagnosis of acute cholecystitis

PURPOSE

To investigate the feasibility of the use of gadobenate dimeglumine (also known as Gd-BOPTA) -enhanced T1-weighted MR cholangiography in diagnosis of acute cholecystitis.

MATERIALS AND METHODS

This prospectively designed institutional review board-approved HIPAA-compliant study was done between January and November 2007. We included 11 consecutive patients (7 male, mean age 59 years) who presented to the emergency room with acute right upper quadrant pain and with equivocal physical examination and/or ultrasound findings. The control group included 15 patients who underwent liver MRI with Gd-BOPTA. All patients underwent contrast-enhanced (CE) MR cholangiography examinations. CE-MR cholangiography was performed on a 1.5 Tesla magnet using 3D T1-weighted high resolution isotrophic volume examination (THRIVE) obtained at the 90th min after intravenous injection of Gd-BOPTA. Imaging features detected on CE-MR cholangiography were correlated with operative and histopathologic findings.

RESULTS

In the control group, GD-BOPTA was visualized within the gallbladder in all subjects. For the study group, gallstones were present in nine patients (n = 7 both in gallbladder and cystic duct, n = 1 only in gallbladder, n = 1 only in cystic duct) on MRCP. Hydropic gallbladder was detected in seven patients, significant wall thickening in seven patients, and pericholecystic free fluid in 6 patients. On delayed phase CE cholangiography, significant enhancement of gallbladder wall was seen in 10 patients, and contrast agent excretion into gallbladder was absent in all patients. Surgery was performed in 10 patients, and cholecystostomy was done in 1 patient. Surgery and histopathology findings were consistent with cholecystitis in all patients.

CONCLUSION

In addition to anatomical assessment, Gd-BOPTA-enhanced MR cholangiography can provide functional evaluation similar to HIDA scintigraphy in diagnosing acute cholecystitis in patients with acute right upper quadrant pain and equivocal findings.