T2-weighted MR Cholangiography Research Articles

High-resolution MR imaging with gadoxetate disodium for the comprehensive evaluation of potential living liver donors.

Several major transplantation centers have used composite multimodality evaluation for the preoperative evaluation of potential living liver donors. This approach can be time-consuming and, although rare, can cause complications. We aimed to demonstrate the clinical feasibility of our comprehensive preoperative MR protocol for the preoperative assessment of living liver donor candidates instead of composite multimodality evaluation. Thirty-five consecutive living liver donor candidates underwent multiphasic liver CT and comprehensive donor protocol MR examinations for preoperative evaluation in a single large-volume liver transplantation (LT) center. Three blinded abdominal radiologists reviewed the CT and MR images for vascular and biliary variations. The strength of agreement between CT and MR angiography was assessed using the kappa index. The detection rate of biliary anatomical variations was calculated. The sensitivity and specificity for detecting significant steatosis (>5%) were calculated. The estimated total volume and right lobe volumes measured by MR volumetry were compared with the corresponding CT volumetry measurements using the intraclass correlation coefficient (ICC). Among the 35 patients, 26 underwent LT. The measurement of agreement showed a moderate to substantial agreement between CT and MR angiography interpretations (kappa values, 0.47-0.79; p < 0.001). Combining T2-weighted and T1-weighted MR cholangiography techniques detected all biliary anatomical variations in 9 of the 26 patients. MR-proton density fat fraction showed a sensitivity of 100% (3/3) and a specificity of 91.3% (21/23) for detecting pathologically determined steatosis (>5%). MR volumetry reached an excellent agreement with CT volumetry (reviewers 1 and 2: ICC, 0.92; 95% CI, 0.84-0.96). Our one-stop comprehensive liver donor MR imaging protocol can provide complete information regarding hepatic vascular and biliary anatomies, hepatic parenchymal quality, and liver volume for living liver donor candidates and can replace composite multimodality evaluation.

High-resolution three-dimensional T1-weighted hepatobiliary MR cholangiography using Gd-EOB-DTPA for assessment of biliary tree anatomy: Parallel imaging versus compressed sensing

PurposeTo compare the quality of images obtained by T1-weighted hepatobiliary MR cholangiography using Gd-EOB-DTPA with 1-mm isovoxel acquisition and compressed sensing (T1-MRCCS) or parallel imaging (T1-MRCPI) for assessment of biliary tree anatomy. MethodWe prospectively reviewed T1-MRCCS, T1-MRCPI, and respiratory-triggered 3D T2-weighted MR cholangiography (T2-MRC) images in 58 patients. Two radiologists independently assessed the three sets of images and scored the biliary tree visualization and overall image quality in all cases using a 5-point Likert scale. The resulting scores were compared among T1-MRCCS, T1-MRCPI, and T2-MRC images using a Friedman test followed by a Scheffe test. The inter-reader agreement in scoring was assessed using κ statistics. ResultsThe image quality scores for the gallbladder on both T1-MRCCS and T1-MRCPI were significantly lower than those on T2-MRC (p < 0.01) for both readers. Meanwhile, the image quality scores for the right and left hepatic ducts and the anterior and posterior branches of the right hepatic duct on both T1-MRCCS and T1-MRCPI were significantly higher than those on T2-MRC (p < 0.05) for both readers. For Reader 2, the overall image quality scores on T1-MRCCS and T1-MRCPI were both significantly higher than those on T2-MRC (p < 0.05). There were no significant differences between the image quality scores on T1-MRCCS and T1-MRCPI for visualization of each bile duct (p < 0.05). ConclusionsThere may be no significant difference in quality between T1-MRCCS images and T1-MRCPI images for assessment of biliary tree anatomy, and both types of images may be better than T2-MRC images, although clinical indication is limited compared with T2-MRC.

Magnetic resonance imaging in liver function analysis. Modern objective reality

Chronic liver disease is a serious worldwide problem because its progression is accompanied by liver fibrosis and cirrhosis at the terminal stages. Primary diagnosis and dynamic assessment of liver fibrosis are essential to determine the prognosis of disease and optimal treatment strategy. Long-term world experience in the use of gadoxetic acid (primovist, eovist) for diagnosis of liver diseases confirms its hepatotropic properties. Thus, magnetic resonance imaging (MRI) in hepatobiliary phase of contrast enhancement is valuable for differential diagnosis of focal liver lesions and assessment of liver structure and fibrotic changes. This review is devoted to the most common methods of contrast-enhanced MRI for assessment of liver function and correlation between severity of diffuse structural liver changes and gadoxetic acid accumulation in liver parenchyma. There is no a single method for MRI-based analysis of liver function that is confirmed by active researches in this direction. It was found that liver biopsy can by unnecessary in some cases if contrast-enhanced MRI with gadoxetic acid is available. The advantage of gadoxetic acid is also elimination properties. Indeed, biliary excretion ensures T1-weighted MR-cholangiography for additional assessment of patency, function and anatomy of the bile ducts. However, there are still several questions in this area that necessitates further research.

Assessment of biliary anatomy in potential living liver donors: Added value of gadoxetic acid–enhanced T1 MR Cholangiography (MRC) including utilization of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) technique in comparison to T2W-MRC

ObjectivesTo assess the added value of gadoxetic-acid–enhanced T1-weighted magnetic resonance Cholangiography (T1W-MRC) including controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA)-Volumetric Interpolated Breathhold (VIBE) technique compared to T2-weighted MR Cholangiography (T2W-MRC) in depicting biliary anatomy in potential living liver donors. MethodsEighty-five potential donors including 34 men with a mean age of 35.6 years (range, 18–55 years) and 51 women with a mean age of 36.7 years (range, 23–57 years), were enrolled in this ethics-approved retrospective study. Image quality for depiction of bile ducts was evaluated by two readers in consensus in 3 separate reading sessions: 1) T2W-MRC alone, 2) T1W-MRC alone (including CAIPI-VIBE and generalized autocalibrating partially parallel acquisitions (GRAPPA)-VIBE techniques, and 3) combined T1W/T2W-MRC. Accuracy of T2W-MRC, T1W-MRC, and combined T1W/T2W-MRC for the identification/classification of the biliary variants was calculated using intraoperative cholangiogram (IOC) as the reference standard. Image quality and reader diagnostic confidence provided by CAIPI-VIBE technique was compared with GRAPPA-VIBE technique. Datasets were compared using the Wilcoxon signed-rank test. ResultsImage quality for depiction of the bile ducts was significantly superior in the combined T1W/T2W-MRC group, when compared to each of T2W-MRC and T1W-MRC groups independently (P value = 0.001–0.034). The combination of CAIPI-VIBE and GRAPPA-VIBE was superior compared to each of the sequences individually. The accuracy of T2W-MRC and T1W-MRC was 93% and 91%, respectively. T1W-MRC depicted four biliary variants better than T2W-MRC. Two variants not well seen in T2W-MRC were clearly shown on T1W-MRC. ConclusionGadoxetic-acid–enhanced T1W-MRC and conventional T2W-MRC techniques are complementary for depiction of biliary variants in potential liver donors and the combination of the two improves the results. The combination of CAIPI-VIBE and GRAPPA-VIBE techniques appear to be complementary for optimal diagnostic yield of T1W-MRC.

A Study on the Usefulness of 3D T1-Weighted MR Cholangiography Through Delay Test Using GD-EOB-DTPA

A Study on the Usefulness of 3D T1-Weighted MR Cholangiography Through Delay Test Using GD-EOB-DTPA

Gadoxetate Disodium-Enhanced MR Cholangiography for Evaluation of Biliary-Enteric Anastomoses: Added Value Beyond Conventional T2-Weighted Images.

OBJECTIVE. The objective of our study was to evaluate image quality and reader confidence in MR cholangiography of bile ducts using conventional T2-weighted MR cholangiography alone in comparison with T2-weighted MR cholangiography and gadoxetate disodium-enhanced MR cholangiography in a series of patients with biliary-enteric anastomosis (BEA). SUBJECTS AND METHODS. Fifty patients with BEA and clinically and sonographically suspected complications underwent 1.5-T MRI. After acquisition of T1- and T2-weighted images, conventional MR cholangiography was performed using 3D fast relaxation fast spin-echo (FRFSE) and single-shot fast spin-echo (SSFSE) T2-weighted sequences (image set 1). In each patient, a 3D fat-suppressed Liver Acquisition with Volume Acceleration (LAVA) sequence was performed before and 15, 20, 25, 30, and 40 minutes after IV administration of 0.1 mL/kg of gadoxetate disodium (Primovist) (image set 2). Two radiologists in consensus evaluated image quality in the anatomic segments of the biliary tract and recorded diagnostic confidence scores for image set 1 alone and image sets 1 and 2 together. MRI findings were compared with postsurgical specimen if surgery was performed, conventional cholangiography, or 12 months of imaging follow-up. RESULTS. A significant improvement in image quality for visualization of all biliary segments was found using gadoxetate disodium-enhanced MR cholangiography in comparison with T2-weighted MR cholangiography alone. Readers judged diagnostic confidence of image set 1 alone and image sets 1 and 2 together as very confident in three and 37 cases, confident in 30 and 11, not confident in 14 and one, and not confident at all in three and 1, respectively. Concordance between image set 1 alone and image sets 1 and 2 together and the reference standard results was present in 23 of 50 cases (46%) and 47 of 50 cases (94%), respectively (p < 0.0001). CONCLUSION. Gadoxetate disodium-enhanced MR cholangiography can improve image quality for visualization of the biliary tract and further enhanced the diagnostic performance of conventional T2-weighted MR cholangiography in the evaluation of patients with BEA.

High spatial resolution navigated 3D T1-weighted hepatobiliary MR cholangiography using Gd-EOB-DTPA for evaluation of biliary anatomy in living liver donors.

To determine the feasibility of high-resolution navigated three-dimensional (3D) T1-weighted hepatobiliary MR cholangiography (Nav T1 MRC) using Gd-EOB-DTPA for biliary visualization in living liver donors and to assess added value of 3D T1-weighted hepatobiliary MRCs in improving the confidence and diagnostic accuracy of biliary anatomy in complementary to T2-weighted MRCs. Twenty-nine right liver donors underwent 3D T2 MRC, 2D T2 MRC, breath-hold T1-weighted hepatobiliary MRC (BH T1 MRC), and Nav T1 MRC. Two readers independently reviewed and compared 3D/2D MRC set, added BH T1 MRC set, and added Nav T1 MRC set for biliary diagnostic accuracy and confidence. For each MRC, biliary segments visualization and image quality were scored. Both BH T1 MRC and Nav T1 MRC improved accuracy and specificity in biliary diagnosis when added to 3D/2D T2 MRC-alone set, though without statistical significance (R1, 82.8% to 93.1%; R2, 82.8% to 89.7%). The added Nav T1 MRC set showed the highest diagnostic confidence with both readers. Both readers scored Nav T1 MRC with the highest visualization scores for branching ducts and overall ducts. Combining T1-weighted hepatobiliary MRCs to 3D/2D T2 MRC set improved accuracy for biliary anatomy diagnosis; time-efficient BH T1 MRC in axial and coronal planes should be considered as a key MRC sequence complementary to T2 MRCs. Given excellent biliary visualization and superior diagnostic confidence, Nav T1 MRC in selected subjects with breath-hold difficulties and inconclusive or complex biliary variations may assist in reaching a correct biliary diagnosis.

Current State-of-the-Art MRI for Comprehensive Evaluation of Potential Living Liver Donors.

This review focuses on the role of state-of-the-art MRI-based techniques for comprehensive evaluation of living donors providing single-visit assessment of the liver vasculature via MR angiography, of the biliary tract via conventional T2-weighted MR cholangiography and T1-weighted gadoxetate disodium-enhanced MR cholangiography, and of hepatic steatosis via T2*-corrected multiecho chemical shift-based water-fat separation MRI and high-speed T2-corrected multiecho MR spectroscopy. By using current state-of-the-art techniques, MRI can provide a one-stop-shop method for evaluation of the potential living liver donors.

3D T2-weighted and Gd-EOB-DTPA-enhanced 3D T1-weighted MR cholangiography for evaluation of biliary anatomy in living liver donors.

To investigate whether the addition of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced 3D T1-weighted MR cholangiography (T1w-MRC) to 3D T2-weighted MRC (T2w-MRC) improves the confidence and diagnostic accuracy of biliary anatomy in living liver donors. Two abdominal radiologists retrospectively and independently reviewed pre-operative MR studies in 58 consecutive living liver donors. The second-order bile duct visualization on T1w- and T2w-MRC images was rated on a 4-point scale. The readers also independently recorded the biliary anatomy and their diagnostic confidence using (1) combined T1w- and T2w-MRC, and (2) T2w-MRC. In the 23 right lobe donors, the biliary anatomy at imaging and the imaging-predicted number of duct orifices at surgery were compared to intra-operative findings. T1w-MRC had a higher proportion of excellent visualization than T2w-MRC, 66% vs. 45% for reader 1 and 60% vs. 31% for reader 2. The median confidence score for biliary anatomy diagnosis was significantly higher with combined T1w- and T2w-MRC than T2w-MRC alone for both readers (Reader 1: 3 vs. 2, p<0.001; Reader 2: 3 vs. 1, p<0.001). Compared to intra-operative findings, the accuracy of imaging-predicted number of duct orifices using combined T1w-and T2w-MRC was significantly higher than that using T2w-MRC alone (p=0.034 for reader 1, p=0.0082 for reader 2). The addition of Gd-EOB-DTPA-enhanced 3D T1w-MRC to 3D T2w-MRC improves second-order bile duct visualization and increases the confidence in biliary anatomy diagnosis and the accuracy in the imaging-predicted number of duct orifices acquired during right lobe harvesting.

Biliary complications following orthotopic liver transplantation: May contrast-enhanced MR Cholangiography provide additional information?

PurposeTo assess whether contrast-enhanced T1-weighted MR Cholangiography may provide additional information in the evaluation of biliary complications in orthotopic liver transplant recipients. Material and methodsEighty liver transplant patients with suspicion of biliary adverse events underwent MR imaging at 1.5T scanner. After acquisition of axial T1-/T2-weighted images and conventional T2-weighted MR Cholangiography (image set 1), 3D gradient-echo T1-weighted fat-suppressed LAVA (Liver Acquisition with Volume Acceleration) sequences were obtained about 30min after intravenous infusion of mangafodipir trisodium (Mn-DPDP,Teslascan®) (image set 2). The diagnostic value of mangafodipir trisodium-enhanced MR Cholangiography in the detection of biliary complications was tested by separate analysis results of image set 1 alone and image set 1 and 2 together. MRI results were correlated with direct cholangiography in 46 patients, surgery in 14 and/or clinical-radiological follow-up in the remaining 20 cases. ResultsThe level of confidence in the assessment of biliary adverse events was significantly increased by the administration of mangafodipir trisodium (p<0.05). Particularly, contrast-enhanced T1-weighted LAVA sequences tended to out-perform conventional T2-weighted MR Cholangiography in the delineation of anastomotic and non-anastomotic biliary strictures and in the diagnosis of biliary leak. ConclusionsContrast-enhanced T1-weighted MR Cholangiography may improve the level of diagnostic confidence provided by conventional T2-weighted MR Cholangiography in the evaluation of biliary complications after orthotopic liver transplantation.

Preoperative staging of gallbladder carcinoma using biliary MR imaging

To evaluate the performance of biliary MRI, including unenhanced imaging, gadolinium-enhanced (Gd-E) dynamic imaging, and MR cholangiography, for the preoperative staging of gallbladder cancer (GBC). Our institutional review board approved this retrospective study. Eighty-six, consecutive patients with surgically resected and pathologically confirmed GBCs and who underwent preoperative MRI, including unenhanced T1- and T2-weighted images, MR cholangiography, and dynamic imaging, were enrolled in this study. Two observers independently evaluated the biliary MR images regarding the T- and N-staging of GBCs and graded their diagnostic confidence for the staging using a 5-point scale. Receiver operating curve analysis was performed to evaluate the diagnostic performance of MR in the staging of GBC. Interobserver agreement was evaluated using kappa statistics. The overall accuracy of T- and N-staging using biliary MRI was 84.9% and 77.9% for observer 1 and 69.8% and 74.4% for observer 2. There was good interobserver agreement regarding the T stage (k = 0.828). The Az (AUC: area under the curve) values of the diagnostic ability of MRI to differentiate ≥ T1b from ≤ T1a lesions, were 0.979 and 0.955 for both observers (P < 0.0001). Biliary MRI with MR cholangiography allows moderately accurate preoperative T staging and N staging of GBCs. It also shows an excellent diagnostic ability for differentiating ≥ T1b lesions from ≤ T1a lesions, which can be helpful for preoperative planning.

Biliary-enteric anastomoses: spectrum of findings on Gd-EOB-DTPA-enhanced MR cholangiography

Biliary-enteric anastomosis is a common surgical procedure performed for the management of a variety of benign and malignant diseases. This procedure presents a high risk of developing complications such as anastomotic leak, hemorrhage, cholangitis, stones, stricture formation, that have been reported as ranging from 3 % to 43 %. Because the endoscopic approach of the biliary tract is generally precluded in this setting, there is clearly a role for a non-invasive imaging technique to follow up these patients and to detect the possible complications. T2-weighted MR cholangiography has been shown to be effective in the evaluation of patients with biliary-enteric anastomosis. Some of these patients may have mild duct dilatation in spite of a patent anastomosis, and stenosis should be considered only when duct dilatation is associated with narrowing of the anastomotic site. T2-weighted MRC depicts the site of biliary-enteric anastomosis, the cause of obstruction, and the status of the biliary ducts upstream. However, the disadvantages of conventional MRC are that it lacks functional information and so, differentiation between obstructive and non-obstructive dilatation of the bile ducts is often extremely difficult. T1-weighted contrast-enhanced MR cholangiography using Gd-EOB-DTPA is a recently emerging technique that is useful for delineating the anatomy of biliary-enteric anastomoses and detecting complications such as strictures, intraductal stones, and biliary leaks; besides, this technique can provide functional information that are extremely promising in the grading of biliary obstruction. We present the spectrum of findings of biliary-enteric anastomoses on Gd-EOB-DTPA-enhanced MR cholangiography focusing on the main clinical applications.

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

ObjectiveTo 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.MethodsNinety-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.ResultsAccuracy 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.ConclusionsGd-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.

Gadoxetic acid–enhanced T1‐weighted MR cholangiography in primary sclerosing cholangitis

To investigate the value of gadoxetic acid-enhanced three-dimensional T1-weighted MR cholangiography (T1w-MRC) in comparison to three-dimensional T2-weighted MR cholangiopancreaticography (T2w-MRCP) in patients with primary sclerosing cholangitis (PSC). Thirty-four MR exams in 29 patients (46.0 ± 16.1 years; 19 men, 10 women) scanned within a 14-month period were retrospectively included. Two abdominal radiologists independently evaluated image quality regarding image contrast, image quality degradation due to artifacts, and visualization quality of ducts. The order of biliary tree branches that were visualized and reader preference toward each method were recorded. Helpfulness of T1w-MRC was scored in consensus. Confirmatory endoscopic retrograde cholangiopancreaticography (ERCP) performed within 3 months of the MR examination was available in 8 patients. Image quality of T1w-MRC and T2w-MRCP was graded good to excellent in all cases. There were advantages for both T1w-MRC (functional information, less degradation due to artifacts) and T2w-MRCP (higher order of visualized branches, better branch depiction). Both readers showed preference for T2w-MRCP; however, both readers found gadoxetic acid-enhanced T1w-MRC helpful in the majority of cases. Gadoxetic acid-enhanced T1w-MRC is complementary to, but should not replace, T2w-MRCP. T1w-MRC is a useful adjunct to T2w-MRCP for morphologic evaluation and provides additional diagnostic information.

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

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. 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 20min 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. 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%. 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.

MRI for evaluation of potential living liver donors: a new approach including contrast-enhanced magnetic resonance cholangiography

To assess the feasibility of a comprehensive MRI protocol using intrabiliary contrast medium (gadolinium-EOB-DTPA) for evaluation of living liver donors. In this prospective study, 30 donor candidates for living-related liver transplantation (17 men; 13 women, mean age 37±10.9years) underwent MRI including MR-angiography (MRA) as well as a conventional T2-weighted MR-cholangiography (MRC) and a contrast-enhanced sequence for depiction of the biliary structures. MRC and MRA images were evaluated for quality on a four-point-scale (score of 0 indicated poor and a score of 3, excellent image quality). Anatomic variants of the arterial, venous, portal venous, and biliary structures were identified. Image quality was diagnostic in all examinations except for 4 of 30 MRA data sets. Intrahepatic biliary structures, especially with regard to the intrahepatic bile ducts of 2nd and 3rd order could be identified with significantly increased image quality than in conventional T2-weighted MRC sequences (P=0.005 and P=0.035). A high percentage rate of anatomic variants regarding the biliary, arterial, venous, and portal venous anatomy was found. This protocol allows the evaluation of liver donors especially with regard to the biliary structures. However, the depiction of the arterial anatomy requires further technical developments.

Gadoxetic acid disodium‐enhanced magnetic resonance imaging for biliary and vascular evaluations in preoperative living liver donors: Comparison with gadobenate dimeglumine‐enhanced MRI

To compare gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) with gadobenate dimeglumine (Gd-BOPTA)-enhanced MRI in preoperative living liver donors for the evaluation of vascular and biliary variations. Sixty-two living liver donors who underwent preoperative MRI were included in this study. Thirty-one patients underwent MRI with Gd-EOB-DTPA enhancement, and the other 31 underwent MRI with Gd-BOPTA enhancement. Two abdominal radiologists retrospectively reviewed dynamic T1-weighted and T1-weighted MR cholangiography images and ranked overall image qualities for the depiction of the hepatic artery, portal vein, hepatic vein, and bile duct on a 5-point scale and determined the presence and types of normal variations in each dynamic phase. Semiquantitative analysis for bile duct visualization was also conducted by calculating bile duct-to-liver contrast ratios. No statistical differences were found between the two contrast media in terms of hepatic artery or bile duct image quality by the two reviewers, or in terms of portal vein image quality by one reviewer (P > 0.05). Gd-BOPTA provided better image qualities than Gd-EOB-DTPA for the depiction of hepatic veins by both reviewers, and for the depiction of portal veins by one reviewer (P < 0.01). The two contrast media-enhanced images had similar bile duct-to-liver contrast ratios (P > 0.05). Regarding diagnostic accuracies with hepatic vascular/biliary branching types, no significant differences were observed between the two contrast media (P > 0.05). Gd-EOB-DTPA could be as useful as Gd-BOPTA for the preoperative evaluation of living liver donors, and has the advantage of early hepatobiliary phase image acquisition.

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

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. 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. 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. 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.

Comparison between T2-weighted MR and contrast-enhanced MR cholangiography in the evalutian of biliary anatomy in liver transplant donor candidates

Objective To compare conventional T2-weighted MR cholangiography (T2WI-MRC) with gadobenate dimeglumine enhanced T1-weighted MR cholangiography(CE-MRC) for evalution of biliary anatomy in liver transplant donor candidates. Methods Thirty-two healthy liver transplant donor candidates were examined with two MR cholangiogaphic methods. For T2WI-MRC, a three-dimensional turbo spin-echo sequence and oblique coronal heavily T2-weighted thick-slab turbo spin-echo imaging sequence were performed. For CE-MRC, three-dimensional fat-suppressed spoiled gradient-echo sequences were performed, with a time delay of 60 minutes following the administration of gadobenate dimeglumine. To compare the depiction of biliary duct anatomy and the artifact caused by intestinal liquid and breathing between the two methods. Intraoperative cholangiography was the reference-standard examination. Results The both methods depicted the biliary anatomy correctly in all 9 cases. The both methods showed the third branches of intrahepatic biliary duct clearly. T2WI-MRC showed interhepatic bihary duct before the third branches in 28 cases (87.5%), CE-MRC showed the same finding in 14 cases (43.8% ). T2WI-MRC showed common bile ducts intermitantly in 2 cases, which were normal in CE-MRC and intraoperative cholangiography. Intestinal liquid affected the image quality of biliary duct in 6 cases (18.8%) performed with T2WI-MRC, but none with CE-MRC. The artifacts caused by breathing were not obvious in the either method. Conclusion T2WI-MRC and CE-MRC both can be used to evaluate bihary anatomy of liver transplant donor candidates, but CE-MRC appears to be more accurate than T2WI-MRC. Key words: Liver transplantation; Contrast media; Magnetic resonance imaging; Comparative study

The Utility of Three-Dimensional of the T1-Weighted MR Cholangiography with Gd-EOB-DTPA for the Evaluation of a Common Bile Duct Obstruction

Purpose: To prospectively assess the utility of the three-dimensional T1 weighted magnetic resonance cholangiography (MRC) with Gd-EOB-DTPA (Primovistⓡ) in patients suspected of having a mild common bile duct obstruction. Materials and Methods: A total of 30 patients suspected of having a mild common bile duct obstruction were enrolled in this study. A T2 weighted MRC and a three-dimensional T1 weighted MRC with Gd-EOB-DTPA (Primovistⓡ) were performed. Within 48 h of the MRC, we performed direct cholangiographies by way of an endoscopic retrograde cholangiography and a surgical cholangiography. Reviews of the data by two experienced radiologists were in consensus. Results: Within 40-60 min of the injection of contrast fluid, the contrast showed the maximum intensity within a common bile duct in 26 of the 30 patients (87%). However, the contrast was poorly visible for as long as 2 hours after injection in 4 of the 30 patients (13%). The sensitivity, specificity, as well as the positive and negative predictive values of the three-dimensional T1 weighted MR cholangiography were 92%, 40%, 88%, and 50%, respectively. Conclusion: The three-dimensional, T1 weighted MRC with Gd-EOB-DTPA (Primovistⓡ) may be a useful ancillary diagnostic modality for evaluating a patient with mild common bile duct obstruction.