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Is It Safe to Get an MRI if You Have Tattoos?

MICHELLE STARR
1 FEB 2019

There are a few things to worry about if you're getting a tattoo, such as finding a hygienic and reputable artist, ending up with ink nanoparticles in your lymph nodes, and potential cancer-like symptoms 15 years down the road. But you can scratch getting an MRI off that list.

 

According to new research, there is very little risk of anything going wrong for tattooed patients when they get a scan.

Wait… little risk? Does that mean there is some risk? As it turns out, yes.

Tattoos are made by using a fine needle to deposit ink below both the dermis and epidermis, where, too big for your immune system to break down, most of the coloured particles will remain permanently.

But not all tattoo inks are created equal. Ink compositions can vary not just between colours, but between manufacturers. So, If you're not careful, as an example, you can end up having an allergic reaction to a particular pigment.

Tattoo inks can contain titanium dioxide, lead, cobalt, chromium, manganese, zinc, copper, nickel and carbon black. They can also contain ferrous pigments such as iron oxides - and this is where an MRI can run into problems.

That's because MRI is short for Magnetic Resonance Imaging, and ferrous materials are magnetic. So when you get into a strongly magnetised tube, and you have ferromagnetic particles under your skin, well, maybe you're not in for such a good time.

 

According to a 2011 report in medical journal Sports Health, one patient even received a 'burn' from his tattoo while undergoing an MRI. "These compounds can theoretically create an electric current that increases the local skin temperature, enough to cause a cutaneous burn," the paper reported.

And according to the FDA, some patients can experience swelling or burning in the tattoo during an MRI.

But, given that millions of tattooed people around the world have MRIs every year without incident, a team of researchers at the Max Planck Institute for Human Cognitive and Brain Sciences in Germany, and the Wellcome Centre for Human Neuroimaging at University College London in the UK set out to determine how high the risk actually is.

They scanned 330 volunteers with at least one tattoo each in an MRI machine, and analysed each tattoo immediately before and afterwards. In all, the study included 932 tattoos, obtained around the world and no more than 20 centimetres (8 inches) in size.

"We found that the majority of the participants did not notice any side effects with tattoos," said physicist Nikolaus Weiskopf of the Max Planck Institute.

 

"There was one specific case where the study doctor found that side effects - a tingling sensation on the skin - were related to scanning. However, this unpleasant feeling disappeared within 24 hours without the affected person having required medical treatment."

In all the researchers estimated that the probability of an adverse reaction was between 0.17 and 0.3 percent - or 1.7 and 3 in 1,000. That's not a huge risk at all. Nor is it zero - but it seems reactions can run the gamut from mild tingling to a burn, so the risk of an extreme reaction is likely lower.

However, it is worth noting, as in a 2005 report in the American Journal of Nursing, that ferrous inks in tattoos can result in imaging artefacts showing up in the scan, resulting in an image that's not diagnostically useful.

But it's not all bad news for tattoo-lovers - the more you get, the stronger your immune system can grow.

It's just another excellent reason to try to investigate the ingredients in your chosen studio's ink before making the plunge.

The team's research has been published in the New England Journal of Medicine.