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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…)
On May 5, 2015, another gadolinium-related study by Kanda et al was published online ahead of print in Radiology. The study, Gadolinium-based Contrast Agent Accumulates in the Brain Even in Subjects without Severe Renal Dysfunction: Evaluation of Autopsy Brain Specimens with Inductively Coupled Plasma Mass Spectroscopy, evaluated brain tissues obtained at autopsy in five randomly selected subjects that had received a gadolinium-based contrast agent (GBCA) at least twice, and five subjects that had no history of GBCA administration. The GBCAs involved were the linear agents Magnevist and Omniscan, and the macrocyclic agent ProHance. Gadolinium was detected in all specimens in the GBCA group, and was found at significantly higher concentrations in the dentate nucleus (DN) and globus pallidus (GP) than the other regions tested. The estimated glomerular filtration rates (eGFRs) of the five subjects in the GBCA group were 47.5, 49.5, 60, 65.5, and 83.4. Kanda and his colleagues concluded that even in subjects without severe renal disease, GBCA administration causes gadolinium accumulation in the brain, especially in the dentate nucleus and globus pallidus. (more…)
On April 6, 2015, a study by Radbruch et al was published online ahead of print in Radiology. Like other recent studies, it reports on evidence of gadolinium retention in brain tissues of patients who had multiple MRIs with a gadolinium-based contrast agent or GBCA. The study, Gadolinium Retention in the Dentate Nucleus and Globus Pallidus Is Dependent on the Class of Contrast Agent, found that increased signal intensity (SI) in the dentate nucleus (DN) and globus pallidus (GP) on unenhanced T1-weighted MR images is caused by serial administration of the linear GBCA gadopentetate dimeglumine (Magnevist), but not by the macrocyclic GBCA gadoterate meglumine (Dotarem).
The retrospective study was comprised of two groups of 50 patients who had undergone at least 6 consecutive MRIs with only the linear agent Magnevist or only the macrocyclic agent Dotarem. All patients had an estimated glomerular filtration rate (eGFR) greater than 60 – which is a level of renal function not considered to be at risk of retaining gadolinium from the administered gadolinium-based contrast agent. Of the 100 patients included in the study, 21 had an eGFR 60-90, and 79 patients had an eGFR greater than 90. (more…)