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Study reports Increasing Signal Intensity within the Brains of Patients with Multiple Sclerosis after multiple injections of the macrocyclic GBCA Gadovist – All Patients had Normal Renal Function
On June 25, 2015, European Radiology published a new study online ahead of print that reports increasing signal intensity on brain MR images after repeated administrations of the macrocyclic agent, gadobutrol (Gadovist, Bayer Healthcare, Berlin, Germany). The study by Stojanov et al is titled, Increasing signal intensity within the dentate nucleus and globus pallidus on unenhanced T1W magnetic resonance images in patients with relapsing-remitting multiple sclerosis: correlation with cumulative dose of a macrocyclic gadolinium-based contrast agent, gadobutrol. This is the first study to report a correlation between the cumulative dose of a macrocyclic, gadolinium-based contrast agent (GBCA), and gadolinium deposition within the dentate nucleus (DN) and globus pallidus (GP) in patients with relapsing-remitting multiple sclerosis (RRMS). All patients had normal renal function at the beginning and end of the study.
Liver function was also normal at the beginning of the study; however, the authors noted that at the end of the study there was a significant increase (p=0.004) in GGT, gamma-glutamyl transpeptidase. The other liver function parameters remained normal.
Since all patients had normal renal function at the beginning and end of the study, there was no correlation between renal function and signal intensity within either dentate nucleus or globus pallidus. The authors noted that, “This suggests that gadolinium deposition within the brain may occur even in patients with normal renal function”. (more…)
New study of Gadolinium retention in brains of rats raises more questions than it answers
On June 22, 2015, an article in Investigative Radiology was published online ahead of print. The study by Robert et al, T1-Weighted Hypersignal in the Deep Cerebellar Nuclei After Repeated Administrations of Gadolinium-Based Contrast Agents in Healthy Rats – Difference Between Linear and Macrocyclic Agents”, describes for the first time “an animal model reproducing closely the recent clinical observations of cerebellum T1 signal hypersignal”. “It also introduces an animal model to investigate the mechanism of the brain retention observed after repeated administrations of some GBCA.”
After 20 intravenous injections of 0.6 mmol of gadolinium per kilogram (4 injections per week for 5 weeks) of gadodiamide (Omniscan) or gadoterate meglumine (Dotarem) to healthy rats, they found that repeated injections of gadodiamide are associated with “progressive and persistent T1 signal hyperintensity in the deep cerebellar nuclei (DCN), with Gd deposition in the cerebellum in contrast with the macrocyclic GBCA gadoterate meglumine for which no effect was observed”. Although repeated doses of gadoterate meglumine (Dotarem) did not cause signal increases, detectable concentrations of gadolinium were found in the cerebellum, cerebral cortex, and subcortical brain of the rats that were injected with it. (more…)
Study suggests Gadolinium Deposition in Dentate Nucleus with MultiHance – Patients had normal renal function
Another 2015 study in Radiology reports findings consistent with gadolinium deposition within the brains of patients with normal renal function (eGFR >60). The study by Ramalho et al, High Signal Intensity in Globus Pallidus and Dentate Nucleus on Unenhanced T1-weighted MR Images: Evaluation of Two Linear Gadolinium-based Contrast Agents”, compared gadodiamide (Omniscan) and gadobenate dimeglumine (MultiHance). The findings related to multiple administrations of gadodiamide are “in agreement with other investigators, who documented signal intensity changes associated with this contrast agent despite the presence of normal renal function”. The authors also reported that, “A significant trend toward relative change in signal intensity was seen in the dentate nucleus (DN), but not in the globus pallidus (GP) after serial applications of gadobenate dimeglumine, suggesting that some gadolinium deposition also may occur with this agent”.
For the first time in the literature, the study established gadolinium accumulation related to the use of gadobenate dimeglumine, which is better known as MultiHance. Of note is the fact that there are no unconfounded cases of NSF associated with the linear ionic gadolinium-based contrast agent (GBCA), MultiHance. However, in this study, the patients in each group had received only one brand of GBCA. Group 1 was comprised of 23 patients that had received between 3 and 11 doses of Omniscan, and Group 2 included 46 patients that had received between 3 and 11 doses of MultiHance. All patients had normal liver and renal function. (more…)
New MRI Safety Certification Exams cover long-term adverse effects of GBCAs
On June 24, 2015, the American Board of Magnetic Resonance Safety (ABMRS) administered exams, which will for the first time, certify Magnetic Resonance Medical Directors/Physicians (MRMD) and Magnetic Resonance Safety Officers (MRSO). A third test, for Magnetic Resonance Safety Experts (MRSE), is expected to be ready for administration on or after the 4th quarter of 2015.
As we previously reported, the purpose of the ABMRS is to improve the safety of medical and research magnetic resonance (MR) environments. That includes the safety of MR facilities and the certification and qualification of the professionals who oversee the physical and operational safety of the MR equipment, environment, and processes.
Dr. Emanuel Kanal, ABMRS Chairman, told us that he included in the examination content requirements that ABMRS certified MR practitioners be familiar with gadolinium based contrast agent safety issues – and that among the issues with which they want them to be familiar are long-term potential adverse effects of the administration of gadolinium-based contrast agents. (more…)
Gadolinium Toxicity 