Study: MRI contrast agent causes harmful metal buildup in some patients

Editor's Note

New research offers a potential explanation for why some patients retain toxic metals long after undergoing an MRI.

Published in the journal Magnetic Resonance Imaging, the findings show that gadolinium contrast agents used in MRI scans may react with common dietary compounds to form harmful metal nanoparticles in the body. As detailed in an April 7 Newsweek report on the study, gadolinium-based contrast agents are injected to sharpen MRI images and are typically excreted without causing harm. However, gadolinium particles have been found lingering in the brain, kidneys, blood, and urine years after exposure, and the US Food and Drug Administration links retained gadolinium to nephrogenic systemic fibrosis (NSF).

The study specifically identifies a chemical reaction between gadolinium and oxalic acid—a compound found naturally in foods and produced in the body after ingesting vitamin C—as a likely contributor, Newsweek reports. Lab tests showed oxalic acid caused gadolinium to separate from its chelating agent and form nanoparticles capable of infiltrating cells in various organs.

Lead author Dr Brent Wagner told Newsweek he personally avoids vitamin C when undergoing MRI with contrast, citing its potential to increase gadolinium reactivity. “Metabolic milieu,” including high oxalic acid levels, could explain why some individuals experience severe symptoms while others do not, he said.

According to the article, nearly half of the patients found to have gadolinium traces in the body had received the contrast agent only once, suggesting that individual biology—not dosage—may influence risk. Dr Wagner theorized that nanoparticle formation could trigger a disproportionate immune response, with affected cells sending distress signals that intensify the body’s reaction.

The research team is now building an international patient registry to further study gadolinium accumulation. According to the article, the registry will collect blood, urine, hair, and fingernail samples to help identify individuals at greatest risk and understand long-term retention patterns.