Could Tattoos Complicate an MRI Scan?
To some, tattoos will always be taboo and unsuitable for the workplace. For many, however, tattoos have become mainstream and are widely accepted in the U.S. Regardless of opinions surrounding tattoo culture, there has always been an underlying health aspect to the body art.
Tattoos are made with pigments inserted into the skin through pricks into the top layer of skin with a needle. Health issues can arise if tattoo artists use unsterile needles or equipment that can spread infections and diseases such as hepatitis, which is why the American Association of Blood Banks requires a one-year wait period between getting a tattoo and donating blood.
While this is a serious and well-known issue, there is another problem that may impact people with tattoos you may not have heard about before – tattoos may cause complications when obtaining MRIs.
“The complications come from some skin irritations caused by the tattoos themselves, but it really depends on the type of tattoos and how big they are,” said Dr. Philip Lim, an Abington-Jefferson Health diagnostic radiologist. “The most common symptoms the patient may complain of are skin irritation or discomfort where the tattoo is while undergoing a study in the MRI machine.”
An MRI, which stands for magnetic resonance imaging, is a test that uses a magnetic field and pulses of radio wave energy to make images of organs and structures inside your body. Often, an MRI gives healthcare providers different information about structures within your body than can be provided by other tests like X-rays, ultrasounds or CT scans. Similarly, MRIs may show problems that can’t be seen with other imaging methods.
But why have people with tattoos or permanent makeup reported experiencing swelling or burning in the tattooed areas during MRIs? According to Dr. Lim, it could be what’s in the tattoo’s ink.
“From what I’ve read, it’s usually tattoos that are black or brown in color that supposedly have more iron oxide in them,” he said. It’s the potential for metallic components in some tattoo pigments that cause the reaction during MRIs.
“It’s basic physics. The MRI machine changes magnetic fields, it causes an electric current to develop into any type of metal. That's why patients may have a burning sensation or pain, because that metal in [the tattoo] is believed to begin to heat,” Dr. Lim explained.
Where someone gets their tattoo done may impact how much burning or pain they feel during an MRI as well.
“Sometimes the tattoo ink companies are not well regulated [abroad] and certainly have poor quality control. They may contain other metals they may not know about. Tattoo artists may get their supply from an ink supplier, possibly from a foreign country that may include metals in the ink,” he said, noting that more metals would mean more skin irritation.
Size and location matter as well. A large tattoo could cause the whole area to be affected during the imaging test. And, in the case of permanent makeup, permanent eyeliner that may contain dark iron oxide could cause a lot of discomfort and possibly some low-grade burns of the eyelid, Dr. Lim said.
Beyond the possibility of burning sensations, the tattoo location could also interfere with the imaging results.
“If there’s iron oxide in the tattoo, we can see there’s a black spot overlying the skin and the tissue. Normally, you would see skin, but now we see a black spot where the anatomy should be,” he said.
If you have a small tattoo on your ankle and you’re MRI is focused on your knee, Dr. Lim said the ink shouldn’t obstruct the image. But it’s when the tattoo is located in the same place the imaging needs to take place that causes an issue.
“The iron causes the signal from the body to be distorted – you cannot tell what is in the area of the anatomy anymore,” he said.
Despite the possibility of interference or reactions during MRIs, there are some things you can do if you have a tattoo.
“Usually, we ask patients about tattoos and the patient is instructed to talk to the MRI tech if they feel any discomfort. The tech will check in on the patient and ask them if they’re ok. And the patient can always press a button to talk to the tech at any time,” Dr. Lim said.
If you do feel pain or discomfort, your MRI tech may stop the scanning and give you a break until the discomfort goes away. You may also try placing a cold or wet towel or cold pack over the tattoo.
Another type of imaging may be used depending on what your healthcare provider is looking for.
“If it’s a tendon, an ultrasound can be used – it’s a fantastic way of looking at things. If you’re looking at bones, ultrasounds don’t work; you may need a CT scan for bones,” he stated.
However, MRIs are great if your healthcare provider needs to look at the joint itself.
“We have different strength MRIs. The stronger the magnetic field, the more likely the [tattoos] are going to be a problem and could cause skin discomfort. If you need an MRI, you may want to ask for a lower strength MRI machine because that may lessen the chance of skin discomfort or burning,” he said.
With a lower strength MRI, the clearness or crispness of the image may be affected. The images are much better with a higher strength MRI, but lower strength could be an option depending on what the doctor wants to learn about your body through the test.