A study published this month in the journal Radiology finds that gadolinium-based contrast agents (GBCAs) are not necessary when monitoring patients with multiple sclerosis.
The use of GBCA's in magnetic resonance imaging (MRI) procedures have come into question in recent years as evidence has emerged linking gadolinium to nephrogenic systemic fibrosis (NSF) and a condition known as gadolinium deposition disease. The issue has come to public attention when actor Chuck Norris and his wife Gena filed a lawsuit claiming that Gena has suffered serious health problems as a result of gadolinium exposure.
Gadolinium toxicity can result in chronic pain, respiratory distress, kidney damage, and cognitive impairment, while NSF presents hardening of the skin, swelling, itching, and pain in the bones.
GBCAs are usually given when a patient with MS is monitored for the development of brain lesions. In most cases, use of a contrast agent is necessary in order to get a clear image from the scan. However, a team of German researchers have found that such enhancement is not needed for such follow-up imaging.
The research team did scans on a total of 507 patients, using an advanced model known as the “3 Tesla” MRI. This particular machine has a more powerful magnet, resulting in clearer images and making it easier to detect abnormal tissues. This made it easier to compare images using GBCAs against those made without the contrast agent. Lead author Dr. Benedikt Wiestler of the Technical University of Munich said, “In over 500 follow-up scans, we missed only four of 1,992 new or enlarged lesions... [more] importantly, we did not miss disease activity in the non-enhanced scans in a single follow-up scan.”
In a press release from the Radiological Society of North America, Wiestler added that their results “...warrant evaluation of strategies for reducing or omitting contrast agent, especially in MS patients who often accumulate a high number of MRI scans over their lifetimes.”
In May, 2017, a study conducted in Lisbon, published in the journal Advances in Chronic Kidney Disease, found that although most gadolinium is eliminated through urination following an MRI scan, a certain amount remains – and can build up over time. This is a serious consideration for patients who must undergo regular MRI scans.
In the wake of these findings, the U.S. Food and Drug Administration began to require warnings for GBCAs, especially for expectant mothers, patients with compromised kidney function, and those who have previously undergone MRIs with a GBCA. The FDA's European counterpart, the European Medicines Agency, went further by suspending nearly all use of GBCAs.
All other considerations aside, the new 3 Tesla MRI systems are rapidly making the use of contrast agents obsolete. Furthermore, eliminating the use of GBCAs makes MRI scans faster and saves on costs. Scientists at Rice University have also found a way to use iron as a contrast agent, which is far less toxic and more economical than gadolinium.