UNM Scientists Discover How Nanoparticles of Toxic Metal Used in MRI Scans Infiltrate Human Tissue
Published in Nanomedicine, Scanners and Imaging.
University of New Mexico researchers studying the health risks posed by gadolinium, a toxic rare earth metal used in MRI scans, have found that oxalic acid, a molecule found in many foods, can generate nanoparticles of the metal in human tissues.
In a new paper published in the journal Magnetic Resonance Imaging, a team led by Brent Wagner, MD, professor in the Department of Internal Medicine in the UNM School of Medicine, sought to explain the formation of the nanoparticles, which have been associated with serious health problems in the kidneys and other organs.
“The worst disease caused by MRI contrast agents is nephrogenic systemic fibrosis,” he said. “People have succumbed after just a single dose.” The condition can cause a thickening and hardening of the skin, heart and lungs and cause painful contracture of the joints.
Gadolinium-based contrast agents are injected prior to MRI scans to help create sharper images, Wagner said. The metal is usually tightly bound to other molecules and is excreted from the body, and most people experience no adverse effects. However, previous research has shown that even in those with no symptoms, gadolinium particles have been found in the kidney and the brain and can be detected in the blood and urine years after exposure.
Scientists are left with intertwined puzzles: Why do some people get sick, when most don’t, and how do gadolinium particles become pried loose from the other molecules in the contrast agent?
“Almost half of the patients had been exposed only a single time, which means that there’s something that is amplifying the disease signal,” Wagner said. “This nanoparticle formation might explain a few things. It might explain why there’s such an amplification of the disease. When a cell is trying to deal with this alien metallic nanoparticle within it, it’s going to send out signals that tell the body to respond to it.”