Magnetic resonance imaging — MRI for short — is a powerful tool physicians use to get detailed pictures of the body without radiation. But the same technology that makes it so valuable can also be hazardous when metal is nearby.
We were reminded of that when a 61-year-old New York man was fatally pulled into an MRI scanner by a metal chain around his neck on Wednesday.
According to News 12 Long Island, the man’s wife was completing an MRI on her knee when she asked the technician to get her husband to help her get off the table. The husband was wearing the 20-pound chain, which he used for weight training.
"The instant" he got close to his wife, she said, “the machine switched him around, pulled him in and he hit the MRI.”
That tragedy raised some questions about just how dangerous metal is in the MRI room.
How does an MRI machine work?
An MRI scanner creates a powerful, constant magnetic field—up to 60,000 times stronger than Earth’s magnetic field, according to the National Institutes of Health. It uses radio waves and computers to generate images of organs, muscles and other soft tissues.
The magnet itself doesn't move. Instead, it aligns hydrogen atoms in the body. Then brief pulses from gradient coils disturb those atoms and measure the signals they emit as they return to alignment — building an image, slice by slice.
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Those loud knocking and thumping sounds heard during an MRI scan are the coils rapidly switching on and off, vibrating due to magnetic forces. Sound levels can exceed 110 decibels — as loud as a rock concert or chainsaw.
Why is metal dangerous in an MRI room?
The MRI magnet attracts ferromagnetic metals like iron, nickel and cobalt. These materials contain atoms that align strongly with magnetic fields. The stronger the magnet, the more intense the pull.
But the magnet doesn’t just attract these metals — it accelerates them.
Even a small object, like a paperclip, key or a hairpin, can be violently pulled toward the magnet at high speed. Large objects, such as oxygen tanks or heavy tools, become deadly projectiles.
This phenomenon is called the “missile effect.” According to the American College of Radiology, objects can fly toward the magnet at speeds of 40 mph or more. The force increases with the object’s mass and the magnet’s strength.
“The projectile effect can cause a metal object to move like a missile, striking with enough force to impale or kill someone,” the radiology college’s safety guidelines note.
In last week’s incident in Westbury, New York, the man was wearing a 20-pound metal chain around his neck when he was pulled into the machine. The exact speed of the chain hasn't been disclosed, but experts say the forces involved can equal hundreds of pounds of pull in milliseconds.
The missile effect has been known for decades, yet such tragedies still occur due to human error, overlooked protocols or unauthorized access.
Are there other risks with metal?
Yes. Even metals that don’t fly can be dangerous.
According to the Food and Drug Administration, implants such as pacemakers, insulin pumps, and aneurysm clips may fail, shift or malfunction in the magnetic field. And some metals can heat up, especially piercings, tattoos with metallic inks or older implants.
Also, any metal in or near the body can interfere with the scan itself, creating blurry or incomplete images.
What are some safety precautions?
Hospitals and radiology clinics follow safety guidelines.
According to the radiology college and Joint Commission, these include screenings of patients and visitors for any metal exposure, implants or medical devices. This should involve ferromagnetic detectors, which are more precise than standard metal detectors.
Providers should also divide MRI suites into safety zones.
MRI patient do’s
- Tell your provider about any implants, medical devices or metal fragments in your body.
- Remove all jewelry, piercings, hearing aids, hairpins and makeup (some cosmetics contain metal flakes).
- Inform the staff if you’ve ever done metalworking, welding,or served in the military (shrapnel risk).
- Ask questions, especially if you’re unsure about what’s safe to bring in.
MRI patient don’ts
- Don’t bring credit cards, phones, keys, pens or tools into the MRI room.
- Don’t assume a metal item is safe just because it’s small.
- Don’t lie about your metals on the screening form — it could be life-threatening.
- Don’t approach the machine unless you’ve been cleared by trained personnel.
