Tattoos Can Cause Burns in MRI Scanners, Doctors Warn

Risk of side effects is very small, but if that’s ferrous ink in your tat don’t be surprised if your skin is suddenly attracted to the machine

FILE PHOTO: A tattooed model presents a creation by designer Maxime Simoens, Paris, France, January 21, 2019.
\ GONZALO FUENTES/ REUTERS

Mom told you not to tattoo Satan on your face, but would you listen? You would not. And now, older, possibly wiser and apparently sick for a totally unrelated reason, the doctors want you to undergo a magnetic resonance imaging scan. The risk is “very small,” but the fact is the machine may heat and even burn your skin if the tat was made with inks that conduct electricity, doctors confirmed in the first systematic study of its kind.

If your skin art was made using ferrous ink (meaning with an iron component), the rest of you may lie there peacefully while your tat finds itself pulled toward the magnet, says Leipzig’s Max Planck Institute for Human Cognitive and Brain Sciences, in a paper published in the New England Journal of Medicine.

Astonishingly, considering how many people have tattoos and how many undergo MRI scanning, the paper was the first systematic prospective study on risk assessment from tats and MRIs. But there you are.

No, the work didn’t begin because somebody with whole-body art caught fire. Countless people with tats have MRI scans and survive without noticing a problem. But not all: Some serious burns were reported among the dedicated skin-art set. At one clinic, doctors began harboring a concern as tattoos went mainstream.

At the Wellcome Centre for Human Neuroimaging in London, volunteers for medical studies were increasingly walking in with tattoos. Prof. Nikolaus Weiskopf, who worked there when the study began in 2011 and since moved to Max Planck, worried how safe they were in the MRI machine. There were stories, but no data on how magnetic scanners and tattooed skin interact.

“Can we conduct our studies with tattooed subjects without hesitation?” he wondered.

Dr. Martina Callaghan, a physicist who picked up the study when Weiskopf left, reassures after eight years of work that the risks are “very small.” But they exist and are worth knowing.

For Israelis, the risks are especially useful to know, given that for a people prohibited by religion to tattoo themselves, they do it a lot. Maybe that’s why they do it so much. Tattoos in Israel have long been within the social consensus.

No tat is going to rip off your skin even if made with pigment particles that contain iron; that side effect of the pull is mainly creepy. Getting burned is another matter.

Some pigments used in skin art are conductive. Normally, the high-frequency field of the MRI is spread out widely over one’s skin, but a conductive tattoo will absorb much of the energy. “It can then happen that the tattoo heats up. In the worst case, this can lead to burns,” Weiskopf explains.

FILE PHOTO: A brain-scanning MRI machine at Carnegie Mellon University in Pittsburgh, November 26, 2014.
Keith Srakocic / AP

Most of the 330 people they tested for tat-MRI interaction had no side effects, and the worst noted was an “unpleasant tingling” – but the doctors created constraints. No single tattoo could exceed 20 centimeters (nearly 8 inches) in area; and no more than 5 percent of the body could be covered by tattoos.

If a person has a lot of tattoos, a covered area like a “sleeve” or a wide swath of torso, and so on – it could be a whole other story. It then becomes a question of whether the disease is serious enough to outweigh the risk of incurring a nasty burn right on Satan’s face.