Japanese researchers warn that gadolinium-based contrast agents, which are used to enhance magnetic resonance image (MRI) test results, could actually distort those images in some cases, potentially placing patients at risk of misdiagnosis.
The study was published online earlier this month by the medical journal Radiology, indicating that repeated use of the contrasting agents may increase MRI signal intensity in certain parts of the brain, which could lead to misinterpretations of the results.
Researchers from the Hyogo Cancer Center and several university medical centers in Japan looked at MRI scans involving 381 patients, including some who had undergone at least six MRIs that were enhanced by gadolinium-based contrasting agents like Omniscan, Magnevist and Optimark.
An analysis of the scans led researchers to determine that signal intensities in the dentate nucleus could lead to misdiagnosis for some patients. They point out that scans suggesting patients with multiple sclerosis had T1 hyperintensity of the dentate nucleus may have been picking up on gadolinium, suggesting that the hyperintensity was not the result of the disease, as some doctors suspected.
Gadolinium Contrast Agent Health Risks
In addition to the risk of misdiagnosis, some experts say they are concerned that the findings of this study suggest that gadolinium, which is toxic, is accumulating in the brain, which could lead to even more health complications.
Gadolinium-based contrast agents are solutions given to patients before they take a MRI in order to get better results. Although the MRI dyes are generally believed to be safe, several years ago concerned emerged after gadolinium contrast agents were associated with a severe and life-threatening condition, known as nephrogenic systemic fibrosis (NSF), which was found to occur among patients with impaired kidney function, causing their skin to thicken and harden, severely restricting movement.
Sometimes referred to as nephrogenic fibrosing dermopathy (NFD) or gadolinium associated systemic fibrosis, NSF is a painful disorder that has no known cure and often results in confinement to a wheelchair and then death.
In 2007, the FDA limited gadolinium contrast agent doses in most patients and contraindicated it for others, which limited the risk of NSF. In September 2010, the FDA went even further and banned the use of Bayer’s Magnevist on patients with kidney problems, due to the heightened risk of NSF. The agency also put similar restrictions on GE Healthcare’s Omniscan and Covidien’s Optimark.
The agency also required label changes for all gadolinium-based contrast agents (GBCAs), warning healthcare professionals to screen patients before injecting a GBCA to identify those suffering from acute kidney injury or chronic, severe kidney disease.