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Tag Archives: GBCAs
Radiologists are in best position to watch patients’ backs
An August 1, 2015 article by Richard Dargan, Radiology Society of North America (RSNA), reviewed recent studies that reported finding evidence of gadolinium retention in the brains of patients with normal renal function. The article, “Radiology Should Take Lead in MRI Contrast Media Use, Research”, also included comments from Emanuel Kanal, M.D., regarding the role radiologists should play in MRI contrast agent research and usage. Dr. Kanal, a Professor of Radiology at the University of Pittsburgh Medical Center (UPMC), chairman of the American College of Radiology MR Safety Committee from 2002-2012, and chairman of the new American Board of Magnetic Resonance Safety (ABMRS), made his comments in an interview with RSNA News.
Recent research has shown that gadolinium-based-contrast agents (GBCAs) are leaving residual gadolinium in the brains of patients, including patients with normal renal function. Two regions in particular have been affected: the dentate nucleus and the globus pallidus. A 2013 study by Kanda et al, first reported finding high signal intensity in those two brain regions on unenhanced T1-weighted magnetic resonance (MR) images that appeared to be related to the increasing cumulative dose of a gadolinium-based contrast agent. Since then, additional studies have been published which confirmed the increased signal intensity is the result of gadolinium accumulation within the brain. (more…)
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…)
Residual or Retained Gadolinium in Patients with Normal Renal Function – What happens next?
On May 5, 2015, an editorial by Emanuel Kanal, MD, Director of Magnetic Resonance Services and Professor of Radiology and Neuroradiology at the University of Pittsburgh Medical Center, and Michael F. Tweedle, PhD, Professor and Stefanie Spielman Chair in Cancer Imaging at The Ohio State University Medical School, was published online ahead of print. The editorial, “Residual or Retained Gadolinium: Practical Implications for Radiologists and Our Patients”, is in the June 2015 issue of Radiology. It addresses the issue of gadolinium retention in patients with normal renal function, as evidenced by published findings by Kanda et al, Errante et al, Quattrocchi et al, McDonald et al, and Radbruch et al.
In December of 2013, a study by Kanda et al first brought attention to what appeared to be evidence of residual gadolinium within the brain tissues of patients without severe renal disease. The evidence of gadolinium in the brain started with reports of abnormal signals in the globus pallidus and the dentate nuclei on unenhanced T1-weighted MR images after repeated prior administration of certain gadolinium-based contrast agents or GBCAs. Other studies found measureable concentrations of gadolinium in normal brain tissues from patients with normal renal (kidney) function. In their editorial, Kanal and Tweedle said, “These provocative findings cause us to reconsider what we know and what we need to learn to better care for our patients”.
The authors said, “We now have clear evidence that the administration of various GBCAs results in notably varied levels of accumulation of residual gadolinium in the brain and bones of patients, even those with normal renal function. What we still do not know is the clinical significance, if any, of this observation.” (more…)
Gadolinium Toxicity 