Administration Of Mangafodipir Trisodium Research Articles

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.

Detection of Neuroendocrine Liver Metastases with MnDPDP-Enhanced MRI

Purpose: The sensitivity of computerised tomography (CT) in detecting neuroendocrine liver metastases is variable and three-phase imaging is advocated. However, patients are often young and may require prolonged follow-up, thus a technique that avoids radiation exposure would be desirable. Our purpose was to assess the diagnostic performance of MRI, before and after administration of mangafodipir trisodium (MnDPDP), in the detection of neuroendocrine liver metastases. Methods: Patients who had undergone single-phase or multi-phase contrast-enhanced MD-CT for neuroendocrine liver metastases were invited to have MRI. Two independent observers made quantitative measurements (number and size of lesions). All measurements were made on each available CT phase and all MRI sequences independently, and repeated after an interval to assess reproducibility. The final number of lesions was agreed on by consensus of three observers. A qualitative assessment (contrast and spatial resolution) and preferred modality were agreed on by consensus. Results: 265 lesions were detected by consensus in 11 patients. Non-contrast CT was available in 4/11, arterial phase in 6/11 and portal phase in 10/11 patients. When compared with the consensus number of lesions, MD-CT identified 17% on non-contrast, 44% on arterial and 43% on portal venous imaging. Lesion detection on MRI was 48% on T₁W, 52% on T₂W and 92% on MnDPDP-MRI. The number of lesions detected on MnDPDP-MRI was closest to the final consensus reading (variance = 0.994, p = 0.0027). The reproducibility of lesion size measurements was best on MnDPDP-MRI (variance = 0.033, p = 0.0021). The preferred modality subjectively was MnDPDP-MRI in 9/11 cases and T₂W MRI in 2/11. Conclusion: MRI is a robust technique in the demonstration of neuroendocrine liver metastases. It is highly reproducible in both detecting the number and measuring the size of lesions. We recommend T₂W MRI and MnDPDP-MRI in detection and follow-up of neuroendocrine liver metastases.

Diagnostic Accuracy of Rim and Segmental MRI Enhancement of Colorectal Hepatic Metastasis After Administration of Mangafodipir Trisodium

The purpose of this study was to determine the diagnostic accuracy of rim and segmental MRI enhancement of hepatic metastasis of colorectal cancer after administration of mangafodipir trisodium (MnDPDP). Sixty-one patients with a potentially resectable hepatic metastasis of colorectal cancer consecutively underwent breath-hold T1-weighted MRI in the axial and coronal planes 30 minutes and 24 hours after administration of MnDPDP. For each lesion, the presence or absence of rim enhancement and segmental enhancement 30 minutes and 24 hours after contrast administration was recorded. These features were evaluated separately for lesions 10 mm in diameter or larger and lesions smaller than 10 mm. The nature of each lesion was determined at histopathologic examination (n = 29) and on follow-up imaging (n = 32). Two hundred thirty lesions were identified at MRI: 210 lesions were metastatic, and 20 were benign. Rim enhancement was observed around 22 of 210 (10%) of the metastatic lesions at 30 minutes and 199 of 210 (95%) of metastatic lesions at 24 hours. Rim enhancement at 24 hours had 94.8% (95% CI, 91.8-97.8%) sensitivity, 90.0% (68.3-98.8%) specificity, 99.0% (97.6-100%) positive predictive value, 62.1% (42.3-79.3%) negative predictive value, and 94.3% (91.4-97.3%) diagnostic accuracy for metastasis. Segmental enhancement was infrequently seen (34/210; 16%) at 24 hours but had 100% (89.7-100%) positive predictive value for metastasis. Rim and segmental enhancement at MRI 24 hours after MnDPDP administration enabled accurate characterization of hepatic colorectal metastasis. These features may aid in preoperative mapping of hepatic tumor burden and disease distribution in patients with colorectal cancer.

Safety and efficacy of Mangafodipir trisodium in patients with liver lesions and cirrhosis.

Mangafodipir trisodium (Mn-DPDP, Teslascan) is a well-tolerated liver contrast agent. Although the enhancement characteristics of the cirrhotic liver after Mangafodipir trisodium administration have been studied, at present there is no published data on the impact that cirrhosis might have on the safety and efficacy profiles of this agent. Our objective is to evaluate by means of a retrospective comparison the safety and efficacy of Mangafodipir trisodium in patients with underlying cirrhosis who were examined for suspicion of focal liver lesions. A total of 923 patients received Mangafodipir trisodium (5 micromol/kg) in 11 prospective randomized European clinical trials. Adverse events and discomfort were recorded and graded in all patients. The efficacy analyses were performed on the subsets consisting of 617 patients with independent lesion counts (detection), and on the subset with 399 patients with independent and onsite final lesion diagnosis (characterization). Of the 399 patients, 149 had histologic confirmation. One hundred eighty of 923 patients (19.5%) had cirrhosis. There were no main differences between cirrhotic and non-cirrhotic patients. Adverse events were observed in 64 patients (6.9%), 6.7% in the cirrhotic group and 7.0% in the non-cirrhotic group, a non-significant difference. Adverse events in most patients were mild or moderate. The presence and intensity of the events did not differ between groups. Discomfort was recorded in 79 patients (8.6%), equally distributed in cirrhotic (6.1%) and non-cirrhotic (9.2%) patients. Regarding lesion count, significantly more lesions were found in the post- than in the precontrast images in both the cirrhotic and non-cirrhotic groups ( p<0.0001). This increase was not influenced by the presence of liver cirrhosis ( p=0.94). Lesion characterization was significantly improved in cirrhotic patients after administration of Mangafodipir trisodium ( p=0.002) but not in non-cirrhotic patients ( p=0.13). Mangafodipir trisodium is a safe and well-tolerated useful contrast agent in patients with cirrhosis.

Liver Lesions: Manganese-enhanced MR and Dual-Phase Helical CT for Preoperative Detection and Characterization—Comparison with Receiver Operating Characteristic Analysis

The purpose of this study was to compare, by means of receiver operating characteristic (ROC) analysis, dual-phase helical computed tomography (CT) and manganese-enhanced magnetic resonance (MR) imaging in the detection and characterization of hepatic lesions in patients prior to surgery. Twenty-five patients known to have or suspected of having hepatic lesions who were eligible for surgery underwent dual-phase (ie, arterial and portal phase) helical CT and phased-array MR imaging (ie, unenhanced fast spin-echo T2-weighted imaging and gradient-echo T1-weighted imaging performed before and after administration of mangafodipir trisodium). All images were reviewed independently by three off-site blinded reviewers who separately reviewed the CT scans and MR images. The standard of reference was findings at surgery, intraoperative ultrasonography (US), and histopathologic examination. ROC curves were established to analyze the results for each reader and modality. Ninety-four lesions (77 malignant and 17 benign) were revealed at surgery, intraoperative US, and/or histopathologic examination. The overall rate of lesion detection for the three readers at CT was 81.9% +/- 7.8, 90.4% +/- 5.9, and 76.6% +/- 8.6. At MR imaging, the detection rates were 72.3% +/- 9.0, 71.3% +/- 9.1, and 69.1% +/- 9.3 (P =.001 for the difference between MR and CT). The average rate of false-positive diagnoses in patients was 14.1% at CT and 6.4% at MR imaging (P =.06 for the difference between MR and CT). The mean areas under the alternative-free-response ROC curves were 0.74 for MR and 0.72 for CT (P =.751, not significant). In detection and characterization of liver lesions, manganese-enhanced MR imaging and dual-phase helical CT were not statistically different.

Potential role of conventional and contrast-enhanced magnetic resonance cholangiography in the evaluation of the acute abdomen in the emergency setting

The imaging evaluation of the acute abdomen in the emergency department usually begins with plain films of the abdomen, although the use of computed tomography (CT) is becoming more prevalent and appropriate. Several studies have shown that CT produces an earlier diagnosis, earlier treatment and improvement in patient care. Furthermore, the use of CT produces a decrease in hospital admissions, unnecessary procedures and cost [1, 2, 3]. Finally, CT is minimally invasive and is readily available, which allows easy scheduling. With the development of rapid magnetic resonance (MR) sequences, torso phased-array coils and stronger gradients, the quality of abdominal MR images has significantly improved over the past decade. Imaging can now be acquired in a breath-hold, with a significant reduction in motion-related artifacts and an increase in contrast and spatial resolution. With the use of modern techniques, MR has been shown to be accurate in the diagnosis of acute appendicitis [4, 5]. Furthermore, Regan et al. demonstrated the accuracy of MR imaging in detecting the presence, location, and cause of small bowel obstruction [6]. However, MR imaging of the acute abdomen is rarely performed in the emergency setting, for several reasons. First, CT can accurately reveal the cause of an acute abdomen in most cases. Second, the literature does not support the use of MR over CT for evaluating the acute abdomen. Third, MR is more expensive than CT. Finally, the limited availability of MR scanners makes it more difficult to schedule an MR imaging study and, as with all new uses of advanced modalities, there is a significant learning curve for interpretation. The greatest potential advantage of abdominal MR imaging over CT in the emergency setting is in the workup of patients with suspected gallbladder and biliary disease. Several studies have demonstrated very good accuracy and greater sensitivity of MR imaging over ultrasound for the diagnosis of acute cholecystitis using fast MR techniques [7, 8]. Since CT is inferior to ultrasound, then MR imaging should be superior to CT for the diagnosis of acute cholecystitis. In addition, even though CT can detect the presence and location of biliary obstruction, it cannot accurately detect the cause of obstruction (stones, strictures) in many cases. MR cholangiography has been shown to be more accurate than CT or ultrasound in detecting the presence, location and cause of biliary obstruction [8, 9, 10, 11]. In fact, the accuracy of MR cholangiography approaches that of endoscopic retrograde cholangiography (ERC), without the invasiveness, cost, contrast or radiation associated with ERC. Therefore, it may be argued that MR cholangiography should replace invasive ERC for the diagnosis of biliary disease [12]. However, this clinical situation should not be considered acute enough to warrant after-hours specialized biliary imaging. Finally, the potential best emergency use of MR imaging of the abdomen is in patients with suspected bile duct leaks. CT can only show secondary findings of a leak (fluid collections, inflammation), but cannot determine the presence of an active leak, detection of which is usually reserved for contrast cholangiography and hepatobiliary scintigraphy. Several studies have shown that MR is valuable in detecting postoperative biliary complications [13, 14]. Contrast-enhanced MR cholangiography is a new technique being investigated for its utility in demonstrating biliary anatomy and detecting the presence and location of bile duct leaks [15, 16]. This exam is acquired with gradient echo (GRE) images between 1 and 2 h after intravenous administration of mangafodipir trisodium (Teslascan, Amersham Health, Princeton, New Jersey) (K.M. Vitellas et al., presented at the American Roentgen Ray Society, May 2001). Since manganese is a paramagnetic metal ion, it shortens the longitudinal Emergency Radiology (2002) 9: 73–74 DOI 10.1007/s10140-002-0196-9

Contrast-enhanced magnetic resonance cholangiography versus heavily T2-weighted magnetic resonance cholangiography.

To investigate the feasibility of contrast-enhanced magnetic resonance cholangiography (CE-MRC) and compare it with single-shot turbo spin-echo magnetic resonance cholangiography (SSTSE-MRC). Fifteen patients with suspected metastatic liver disease (n = 10) or biliary tree abnormalities (n = 5) underwent a magnetic resonance imaging (1.5-T system) examination before and after mangafodipir administration. Contrast-enhanced MRC with a three-dimensional fast low-angle shot sequence after mangafodipir trisodium administration was compared with SSTSE-MRC. Four anatomic segments were evaluated: the intrapancreatic and extrapancreatic common bile duct segments, the cystic duct, and the area of hepatic bifurcation. Contrast-enhanced MRC and SSTSE-MRC were separately analyzed on a 5-point grading scale in terms of ductal segment visualization and lumen narrowing or dilatation. There was no difference (P = 0.375) in segment visualization between CE-MRC and SSTSE-MRC; 56 of the 60 segments were visualized by both techniques. In the evaluation of ductal narrowing or dilatation, nonsignificant differences (P = 0.500) were observed. Contrast-enhanced MRC was not influenced by fluid superimposition and provided additional information from background tissues. Contract-enhanced MRC is a feasible technique showing anatomic correlation with SSTSE-MRC, and it can in addition provide functional information. Contrast-enhanced MRC may be used in selected patients when traditional SSTSE-MRC is inconclusive.

Lymph Node Enhancement at MRI with MnDPDP in Primary Hepatic Carcinoma: TECHNICAL REPORT

AIMS: To report two cases of lymph node enhancement in primary hepatic carcinoma following the administration of Mangafodipir trisodium (MnDPDP, Teslascan®, Nycomed Amersham U.K.), an hepatocyte specific magnetic resonance imaging (MRI) contrast agent. To review our experience with this contrast agent and the literature to establish if such enhancement occurs in normal lymph nodes or has been previously described in hepatocellular carcinoma (HCC) or other lesions.MATERIALS AND METHODS: The radiological reports of all MnDPDP enhanced abdominal MRI examinations were reviewed for lymph node enlargement. The MR images from examinations with reported nodal enlargement were re-evaluated for evidence of nodal enhancement and the hospital notes and histological reports were reviewed. Nodal enhancement was considered present if lymph node signal intensity was greater than that of the spleen following MnDPDP. Literature searches were performed on Medline and PubMed for previous descriptions of lymph node enhancement following MnDPDP.RESULTS: The reports of 90 MnDPDP abdominal MRI examinations were reviewed. Of 18 cases of lymph node enlargement, two had evidence of lymph node enhancement following MnDPDP. These two cases had hepatocellular carcinoma and fibrolamellar hepatocellular carcinoma, respectively, confirmed on liver biopsy. No reports of lymph node enhancement following MnDPDP were identified in the literature.CONCLUSION: Two cases of lymph node enhancement following MnDPDP have been presented. Although histological confirmation of the lymph nodes was not obtained, the authors propose that the lymph node enhancement was due to functioning hepatocytes in lymph node metastases from the patients' histologically confirmed hepatocellular carcinomas.Burkill, G. J. C., Mannion, E. M. & Healy, J. C. (2001). Clinical Radiology56, 67–71.

Sequence optimization in mangafodipir trisodium-enhanced liver and pancreas MRI.

To find an optimal magnetic resonance (MR) sequence for mangafodipir trisodium-enhanced liver and pancreas imaging, six healthy volunteers were studied using a 1.5 T MR system with different T1-weighted abdominal imaging sequences. These were turbo field (gradient)-echo (TFE), fast field (gradient)-echo (FFE), and spin-echo sequences before and after mangafodipir trisodium administration. Various parameter combinations were investigated within each sequence type, and then the best combination was found and compared with those of the other sequences. Signal intensity (SI) measurements were made in regions of interest in the liver, pancreas, and a reference marker with a known T1 value. Contrast index (CI, SItissue/SImarker) and contrast-to-noise ratio (CNR, [SItissue/SImarker]/SDbackground) were calculated, and percentage CI increase and CNR in the postcontrast images were used for the best sequence evaluation. Regarding CI, the TFE sequence with a TR/TE/flip angle of 15 msec/4.6 msec/20 degrees and inversion time of 300 msec had the largest pre- to postcontrast percentage increase. The FFE sequence with a TR/TE/flip angle of 140 msec/4.6 msec/90 degrees had the highest postcontrast CNR and is considered to be the optimal sequence for mangafodipir trisodium-enhanced MR imaging of the liver and pancreas.