Feature | December 18, 2013

Contrast Agent Linked With Brain Abnormalities on MRI

December 18, 2013 — For the first time, researchers have confirmed an association between a common magnetic resonance imaging (MRI) contrast agent and abnormalities on brain MRI, according to a new study published online in the journal Radiology. The new study raises the possibility that a toxic component of the contrast agent may remain in the body long after administration.

Brain MRI exams are often performed with a gadolinium-based contrast medium (Gd-CM). Gadolinium’s paramagnetic properties make it useful for MRI, but the toxicity of the gadolinium ion means it must be chemically bonded with non-metal ions so that it can be carried through the kidneys and out of the body before the ion is released in tissue. Gd-CM is considered safe in patients with normal kidney function.

However, in recent years, clinicians in Japan noticed that patients with a history of multiple administrations of Gd-CM showed areas of high intensity, or hyperintensity, on MRI in two brain regions: the dentate nucleus (DN) and globus pallidus (GP). The precise clinical ramifications of hyperintensity are not known, but hyperintensity in the DN has been associated with multiple sclerosis, while hyperintensity of the GP is linked with hepatic dysfunction and several diseases.

To learn more, the researchers compared unenhanced T1-weighted MR images (T1WI) of 19 patients who had undergone six or more contrast-enhanced brain scans with 16 patients who had received six or fewer unenhanced scans. The hyperintensity of both the DN and the GP correlated with the number of Gd-CM administrations.

“Hyperintensity in the DN and GP on unenhanced MRI may be a consequence of the number of previous Gd-CM administrations,” said lead author Tomonori Kanda, M.D., Ph.D., from Teikyo University School of Medicine in Tokyo and the Hyogo Cancer Center in Akashi, Japan. “Because gadolinium has a high signal intensity in the body, our data may suggest that the toxic gadolinium component remains in the body even in patients with normal renal function.”

Kanda noted that because patients with multiple sclerosis tend to undergo numerous contrast-enhanced brain MRI scans, the hyperintensity of the DN seen in these patients may have more to do with the large cumulative gadolinium dose than the disease itself.

The mechanisms by which Gd-CM administration causes hyperintensity of the DN and GP remain unclear, Kanda said. Previous studies on animals and humans have shown that the ion can be retained in bone and tissue for several days or longer after administration.

“The hyperintensity of DN and GP on unenhanced T1WI may be due to gadolinium deposition in the brain independent of renal function, and the deposition may remain in the brain for a long time,” Kanda suggested.

Kanda emphasized that there is currently no proof that gadolinium is responsible for hyperintensity on brain MRI. Further research based on autopsy specimens and animal experiments will be needed to clarify the relationship and determine if the patients with MRI hyperintensity in their brains have symptoms.

“Because patients who have multiple contrast material injections tend to have severe diseases, a slight symptom from the gadolinium ion may be obscured,” Kanda said.

There are two types of Gd-CM , linear and macrocyclic, with distinct chemical compositions. Since the patients in the study received only the linear type, additional research is needed to see if the macrocyclic type can prevent MRI hyperintensity, according to Kanda.

For more information: radiology.rsna.org

Related Content

Elekta Unity High-Field MR-Linac Receives CE Mark
News | Image Guided Radiation Therapy (IGRT) | June 18, 2018
Elekta announced that its Elekta Unity magnetic resonance radiation therapy (MR/RT) system has received CE mark,...
Washington University in St. Louis Begins Clinical Treatments With ViewRay MRIdian Linac
News | Image Guided Radiation Therapy (IGRT) | June 14, 2018
June 14, 2018 — The Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine in S
PET/CT Changes Care for 59 Percent of Suspected Recurrent Prostate Cancer Cases
News | Prostate Cancer | June 13, 2018
A recently presented investigational clinical trial evaluated the impact of 18F fluciclovine positron emission...
Accuray TomoTherapy System Beneficial in Two Total Body Irradiation Studies
News | Radiation Therapy | June 13, 2018
Recently published data from two new studies demonstrate the benefits of Accuray’s TomoTherapy System in the delivery...
Women More Likely to Use Other Preventive Health Services Following Mammography
News | Mammography | June 13, 2018
Medicare beneficiaries who undergo breast cancer screening with mammography are more likely than unscreened women to...
Reduced hippocampal volume on MRI

This figure shows reduced hippocampal volume over the course of 6 years as seen on progressive volumetric analysis and also coronal MRI evaluations (arrows).Progressive volume loss in the mesial temporal lobe on MRI is a characteristic imaging feature of AD. This patient was a case of Alzheimer’s Dementia.

 

News | Neuro Imaging | June 12, 2018
According to a UCLA Medical Center study, a new technology shows the potential to help doctors better determine when...
High Prevalence of Atherosclerosis Found in Lower Risk Patients
News | Magnetic Resonance Imaging (MRI) | June 08, 2018
Whole-body magnetic resonance angiography (MRA) found a surprisingly high prevalence of atherosclerosis in people...
Philips Receives FDA 510(k) for Ingenia Elition MR System
Technology | Magnetic Resonance Imaging (MRI) | June 07, 2018
Philips announced that it has received 510(k) clearance from the U.S. Food and Drug Administration (FDA) for its...
Lung Decision Precision
News | Lung Cancer | June 04, 2018
For smokers and former smokers, the threat of lung cancer always lurks in the shadows.
New Ultrasound Guidelines Reliably Identify Children Who Should be Biopsied for Thyroid Cancer

Image courtesy of Loyola Medicine

News | Pediatric Imaging | May 29, 2018
A Loyola Medicine study has found that new ultrasound guidelines can reliably identify pediatric patients who should be...
Overlay Init