Anyone who’s had a magnetic resonance imaging, or MRI, scan knows that jewelry and metal are a big no-no inside the imager. What about yoga pants?
While they might seem like a smart choice for a scan, hospitals across the U.S. have in recent years started banning yoga clothing, lycra, spandex and other athletic wear from MRI appointments, reports MarketWatch.
Athletic clothing — and undergarments — can contain metallic microfibers to deter odor and bacteria, the publication reported. In a magnetic field, such as those used for MRI scans, those metal fibers can heat up and produce burns.
“Because you’re going into a magnet,” Sara Lamothe, a MRI Technologist at Lakeridge Health in Canada, told Global News Canada. “You’re putting metal into a magnet. It can actually react and spark or heat up and burn them.”
The risks may not be evident to people just looking for something comfortable to wear in a potentially uncomfortable situation.
“I suspect many patients are unaware of the clothing risks,” Bradley Delman, an associate professor of radiology at Mount Sinai Health System, told MarketWatch. “Even very comfortable clothing can present unnecessary risks. Safety must come first.”
The Stanford University Center for Cognitive and Neurobiological Imaging posted a warning online in 2016 on Lululemon and other popular yoga brands. The notice also warns MRI patients to beware of metal buttons in some boxer shorts and metal stays in bras.
In 2012, the American Journal of Neuroradiology published a case involving an 11-year-old girl who received second-degree burns from silver microfibers in her undershirt during an MRI for scoliosis.
In 2014, patient Jen Marr felt a burning sensation in her legs so strong that she had to ask the radiologist to stop the scan, reported Global News Canada. She was wearing yoga pants.
“I said I’m burning,” Marr told the publication. “‘What do you mean you’re burning?’ Like I’m burning. My legs are on fire.”
Experts suggest checking the tags on any clothing before wearing it to an MRI scan.
“If you see the label, anti-microbial, in other words it kills microbes or bacteria, it mostly like does that with silver technology,” Alison Matthews David, an assistant professor at Ryerson University, told Global News Canada.