Preliminary research by a team of medical experts found that magnetic resonance imaging (MRI) scans with contrast can create nanoparticles that infiltrate the body tissues. The research, published in the journal Magnetic Resonance Journal, needs to be confirmed by further studies. However, its findings cast some doubts on the safety of MRI scans, which are an important tool for medical diagnosis. Researchers conducted test tube experiments to look for the presence of oxalic acid, a compound found naturally in many foods that bind with metal ions. They looked particularly at the impact of oxalic acid on gadolinium, a metal used as an MRI contrast agent (a substance injected into the body to change the presence of water molecules to create better-quality images). The results of the tests showed that oxalic acid caused small amounts of gadolinium to create nanoparticles that infiltrate the cells of different organs.
Dr. Richard Reitherman, a radiologist and medical director of breast imaging at MemorialCare Breast Center at Orange Coast Medical Center in Fountain Valley, CA, emphasized that gadolinium is usually expelled from the body after the MRI through urination and does not cause bad health effects in most people. However, some studies found it lingering in the body after MRI with contrast, and in some cases even years after someone was exposed to it. Gadolinium is used mainly for breast, pelvic, brain, and abdominal MRIs. According to Jeffrey Luci, research assistant professor of biomedical imaging physics at the Rutgers Center for Advanced Human Brain Imaging Research, the gadolinium atom on its own is toxic, but when used as a contrast agent for MRI, it is wrapped up in a large organic molecule that is designed to prevent it from becoming free. This allows it to be expelled from the body without consequences. However, some people develop severe complications after an MRI with gadolinium-based contrast agents, including kidney injury and brain damage. These complications happen in just 0.03% of cases. Yet Dr. Kelly Johnson-Arbor, a toxicologist at MedStar Health, noted that exposure to gadolinium-based contrast agents can increase the risk of nephrogenic systemic fibrosis (NSF) in people with chronic kidney disease. NSF is characterized by skin swelling, thickening, and pain.
Dr. Reitherman said that more work is needed to understand the impact of gadolinium on the body and the role of the nanoparticles it can create during the MRI scan. The results of the research are just theoretical and must be proved through human experimentation. Luci also stressed that people should not be scared to get an MRI if it is medically necessary. As pointed out by Reitherman, contrast is not always used, and experts agree that the process is generally safe and reliable for medical purposes.
