The Risky Reason You Can't Wear Yoga Clothes When Getting An MRI

Between PET scans, CT scans, MRIs, and more, it's hard to keep all those acronyms straight. Standing for magnetic resonance imaging, an MRI produces high-quality images of a patient's tissues, organs, and skeleton to help clinicians identify various possible health issues (via Mayo Clinic). This can include multiple sclerosis, aneurysms, stroke, tumors, and brain damage, among others.

An MRI machine works by using magnets to realign atoms within the body and prompts them to give off energy signals that the machine can convert into images. Because of these magnets, however, any metal brought into the machine can interfere with the accuracy of the images and potentially pose a safety risk to patients. This goes beyond external jewelry pieces and also includes metal inside the body — including intrauterine devices (IUDs), screws and plates, cochlear implants, artificial heart valves, and more.

Because you're remaining still for an extended period of time, comfy clothes are a must when it comes to an MRI. However, you may want to rule out yoga clothes. Here's why.

While they certainly provide us with plenty of stretch and comfort, some yoga clothes could pose a risk of burns if worn inside an MRI machine, reports The Washington Post. Obviously, you'll plan to leave anything with zippers or metal buttons at home. But just because there isn't any metal within clear sight doesn't mean it isn't there. In fact, below the fabric surface of your favorite leggings may be metallic fibers. These are often found in clothing branded as antibacterial or antimicrobial.

These fibers may be effective at stopping body odor in its tracks. But patient case reports reveal that they can also cause significant skin damage if worn during certain types of MRI scans. With some patients having suffered second- and third-degree burns, Dr. Hollis Potter, chairman of the radiology and imaging department at the Hospital for Special Surgery in New York City, told The Washington Post, "It's like putting your skin up against a hot plate." While not all yoga clothes pose this risk, experts at Mather Hospital explain that many medical facilities prohibit patients from wearing spandex, lycra, and yoga clothes altogether as a precaution.

While some popular activewear brands, such as Lululemon, openly promote their use of Silverescent metal fiber technology, companies are only required to report metal fibers that exceed 5% of the item's makeup, reports The Washington Post. Therefore, it can't be 100% guaranteed that your yoga clothes are completely fiber-free.

So what's the safest outfit to show up in on the morning of your MRI appointment? Experts at Mather Hospital suggest sticking with 100% cotton shirts and sweatpants as a safe and comfy option. However, it's also possible that your technician may hand you a gown instead. Many hospitals have been moving toward this as standard procedure to reduce any clothing-related health risks. In addition, remember to take off all metal accessories, including watches, hairpins, and eyeglasses. Although you may not think of these items right off the bat, you also won't want to forget about dentures, wigs, underwire undergarments, as well as makeup made with metal particles.