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Purpose: Using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in a rat glioma model, and nested model selection (NMS), to compare estimates of the pharmacokinetic parameters vp, Ktrans, and ve for two different contrast agents (CAs)-gadofosveset, which reversibly binds to human serum albumin, and gadopentetate dimeglumine, which does not. Materials and Methods: DCE-MRI studies were performed on nine Fisher 344 rats inoculated intracerebrally with 9L gliosarcoma cells using both gadofosveset and gadopentetate. The parameters vp, Ktrans, and ve were estimated using NMS. Results: Ktrans estimates using gadofosveset, compared to gadopentetate, differed in their means (gadofosveset 0.025 ± 0.008 min-1 vs. gadopentetate 0.046 ± 0.011 min-1; P = 0.0039). This difference notwithstanding, the intraclass correlation coefficient (ICC) for the two estimates of Ktrans showed nearly perfect linear dependence (ICC = 0.8479 by Pearson's r). Other estimates, ve (gadofosveset 22.7 6 4.7% vs. gadopentetate 23.6 6 5.6%; P = 0.4258) and vp (gadofosveset 1.5 6 0.5% vs. gadopentetate 1.6 6 0.4%; P = 0.25), were not different in their means between the two CAs, and there was almost perfect agreement for ve (ICC = 0.8798) and substantial agreement for vp (ICC = 0.7981) between the two CAs. Conclusion: Estimates of Ktrans were statistically different using gadofosveset and gadopentetate, whereas ve and vp were similar with two CAs. NMS produced robust estimates of pharmacokinetic parameters using DCE-MRI that show promise as important measures of tumor physiology and microenvironment. [ABSTRACT FROM AUTHOR]

Nephrogenic systemic fibrosis (NSF) is a systemic disorder that occurs in patients with renal failure and manifests as a thickening of the skin and flexion contractures of the joints. The etiology may involve an exposure to a gadolinium (Gd)-based magnetic resonance contrast agent. It has been proposed that in hemodialysis (HD) patients, iron mobilization (decreased total iron-binding capacity, increased iron level, and transferrin oversaturation) causes a transmetallation reaction and the release of free Gd from its chelator with the deposition of both Gd and iron in the affected tissues leading to fibrosis. The objective of this study was to investigate whether the use of gadopentetate dimeglumine leads to iron mobilization and to the development of NSF in HD patients. A retrospective chart analysis of 236 HD patients was performed and patients who had received a Gd-containing contrast agent were selected for analysis of their iron studies before and after the Gd exposure. A total of 25 patients were identified as having had a magnetic resonance imaging study and all were administered gadopentetate dimeglumine and no patients had any signs or symptoms suggestive of NSF. Six patients had the appropriate iron studies, which showed no statistically significant difference in the serum iron, total iron-binding capacity, ferritin, or transferrin saturation before and after exposure to gadopentetate dimeglumine. Our data suggest that the use of gadopentetate dimeglumine in HD patients did not cause iron mobilization and transmetallation therefore may partially explain the lack of development of NSF seen in our patient population. [ABSTRACT FROM AUTHOR]

Nephrogenic system fibrosis is a rare disease affecting patients with severe renal insufficiency or dialysis. Its aetiology is incompletely understood. Evidence is growing that gadolinium contrast media is a major risk factor, whereby risk increases with larger cumulative doses. The role of other risk factors, such as inflammation or electrolyte disturbances, is less clear. All published cases to date received gadodiamide, gadopentetate or gadoversetamide, which are considered to be less stable due to a linear molecular structure. The aetiological significance of stability differences between the non-ionic linear, ionic linear and macrocyclic agents remains to be shown. For prevention, strict indications for MRI in risk patients can be combined with Food and Drug Administration (FDA) or European Medicines Agency (EMEA) guidelines. These recommend checking for renal impairment by history or laboratory tests. The FDA recommends avoidance of all gadolinium contrast media in patients with renal insufficiency grades 4 and 5 (glomerular filtration rate <30 mL/min per 1.73 m2) or any grade of acute renal failure in liver transplantation patients or candidates. The EMEA differentiates between agents and advises avoidance of only gadodiamide and gadopentetate in the same patient categories. Other gadolinium contrast media should only be used after careful consideration of risks versus benefits. Post-procedural haemodialysis is only indicated in patients on regular dialysis. [ABSTRACT FROM AUTHOR]

For many years, alternatives to iodinated X-ray contrast media have been sought. Of the contrast media investigated to date, only CO(2) and the gadolinium-chelates have been shown to be viable alternatives for selected X-ray examinations. Therefore, we have reviewed the general literature and that specific for gadopentetate (Magnevist) in particular, since this agent has been studied the most. This review indicates that diagnostic CT examinations can be achieved following the intravenous administration of gadolinium-containing contrast media (CM) for evaluation of aortic abnormalities. Gadolinium-containing CM at the dose approved for MR imaging are not useful for CT evaluation of the abdominal parenchymal organs. Intravenous/intraarterial injections have also been used in a variety of angiographic and interventional procedures. Image quality, however, is generally inferior to iodinated contrast media. Gadolinium-containing CM require no special handling and can be administered by hand injection or via conventional angiographic automated injectors with the same flow rates and pressures as are used with iodinated contrast media. For CT, a peripheral bolus injection of a diluted gadolinium agent (1:1 with saline) of 60-90 ml at 3-5 ml/s is usually performed. Similar to all other gadolinium-chelates, the non-MRI use of gadopentetate (Magnevist) is not approved by regulatory agencies. However, the literature suggests that a dose of 0.3-0.4 mmol/kg b.w. has been safely administered for CT as well as for angiography and interventional procedures intravenously and intraarterially. Even at this dose, though, this results in a relatively small overall volume to be injected, which limits utility somewhat. [ABSTRACT FROM AUTHOR]

Purpose: To study the incidence of adverse events after i.v. injection of MR contrast agents in a Chinese population. A comparison was made between an ionic contrast agent (dimeglumine gadopentetate, Magnevist) and a non-ionic contrast agent (gadodiamide, Omniscan).Material and Methods: During a 24-month period, 2,049 Chinese patients who randomly received an i.v. bolus injection of either Magnevist or Omniscan were investigated. All patients were questioned for the presence of any generalized or localized adverse reaction on the following day after the MR examination according to a standardized questionnaire.Results: Three hundred and nine out of 2,049 patients (15%) reported an adverse event. There was a higher incidence of adverse events in patients receiving Magnevist as compared to those receiving Omniscan injection. All reported adverse events were clinically mild and required neither treatment nor hospitalization.Conclusion: There was a higher incidence of adverse reaction in patients receiving Magnevist than in those receiving Omniscan. [ABSTRACT FROM AUTHOR]

We would like to describe a case of MRI lymphangiography of the left leg, performed by subcutaneous injection of gadopentetate in the foot, followed by serial acquisitions of images, in a 52-year-old female, who presented to us with progressive leg swelling following total hysterectomy and radiation therapy. Successful demonstration of lymphatic channels, along with faint visualization of the venous system, was achieved. This technique allows excellent visualization of lymphatic channels. [ABSTRACT FROM AUTHOR]