THink Tech Talk #4 – MRI Safety

MRI Safety and Iron-Oxide Based Pigments

Some THink MBC customers have asked us if iron oxide-based pigments are a problem for MRI scans.

MRI, or Magnetic Resonance Imaging, is used to develop a computerised image of internal body structures. Unlike the radiation used in an X-ray, MRI uses extremely powerful rotating magnetic fields. Compounds containing iron (and many other metals) are attracted to a magnetic field, however most substances produce a magnetic field in the presence of a strong enough magnet (which is how the image is created).

MRI Scan In Progress

Most cosmetic tattoo pigments contain iron, with several other metals being common. Some pigments are carbon-based (organic) with no metals. Metals will response to MRI to some degree, although the amounts in a cosmetic tattoo are obviously very small. Body art tattoos may present more of a risk as they are typically much bigger and contain various metals.

Complications with MRI cosmetic tattoos are extremely rare. A paper in Journal of Magnetic Resonance Imaging (2002) concluded that “MR imaging may be performed in patients with permanent cosmetics without any serious soft tissue reactions or adverse events. ….permanent cosmetics should not prevent a patient from undergoing MR imaging”.

In a survey of 135 MRI patients with a cosmetic tattoo, 1.5% reported problems.
One reported “tingling” and the other a temporary “burning” sensation. There is a reported case of first degree burns in eyelids. Here the pigment was found to contain lead, arsenic, cadmium and mercury. These are toxic heavy metals that have (dia)magnetic properties causing them to heat up much more than iron. They should never be in a cosmetic tattoo pigment.

What to do:

• As a precaution, tell your doctor you have cosmetic tattoos before an MRI.
• Tell your clients to do the same.
• Always use good quality pigments.