MRI Safety: Everything We Do To Keep You Safe

Fridge Magnets

MRI Safety: Everything We Do To Keep You Safe

Vigilance is what has kept us and our patients safe, so it’s good to stop, think and respect the power of magnets.


Radiology as a field comes with a few misconceptions including that it always involves radiation. Many types of medical imaging utilize radiation – CTs and x-rays for example. But MRI does not.


Magnetic resonance imaging (MRI) uses powerful magnets, radio frequency waves and computers to create amazing images of the human body. The magnets we use are not the average alphabet-on-the-fridge variety. They are large, heavy and very strong. They can pull a metal object from your hand, across the room! Ordinary things like scissors or mops with metal handles can become lethal missiles in the MRI suite.


Because of this, we carefully screen anyone who enters the MRI suite as any metal can cause harm to patients, technologists and to the machine itself. In fact walking down our halls you may notice red tape on the floors demarking the “magnetic zone.” The technologists who work in MRI actually have special work badges that are all plastic – no metal clips.


Through our own experience we know a few things:


  1. It’s ok and quite necessary to speak up when there is a safety question. Safety is our #1 (and #2 and #3) priority. Ask, ask, ask.
  2. Sometimes humans are forgetful – a lurking hairpin or forgotten belly button ring can be waiting to cause havoc. Changing to a dressing gown can help to avoid the “I forgot there was a battery in my pocket” problem.
  3. We check and recheck for surgical implants, metal prosthetics and implanted devices like nerve stimulators multiple times and in multiple ways as these can affect and be affected by the magnet. Rechecking is essential – patients may not be aware of what they have and sometimes further investigations are needed as to the safety of a particular device. This can take time, so knowing beforehand is key.
  4. Certain colors of tattoos, some decorations/inks on clothing and even shiny nail polishes can have traces of metal in them. These amounts of metal are not enough to pull your body up against the machine, but sometimes a slight warming sensation in that area will occur. The trace metals can distort the images, so avoiding these when possible is best.


If you want more information or a visual on the power of MRI, you can watch of a video of some other people playing with an out-of-use MRI machine. Note that if you can’t bench a few hundred pounds, you may have trouble prying a wrench off an MRI machine. And, as Mythbusters Jamie and Adam would tell you, don’t try this at home (fun and mischievous as it looks, we never play with the magnets at work!).


Image credit: Fridge Magnets by Sarnil Prasad. Copyright Creative Commons Attribution 2.0 Generic (CC BY 2.0)