MRI scanners uses strong magnets to produce incredible, detailed pictures of your organs and joints. We’ve written about the best ways to prepare for your MRI, but if you have any metal in your body, you’ll need to ensure that it (and you) are “compatible” with the magnet.
The magnet is strong enough to move a car, so any metal in your body could heat up or get pulled out. The most common sources of trouble are surgical implants, medication patches, and shrapnel. In some cases tattoos can also heat up and cause burns.
If you’ve never had an invasive procedure, don’t use any medications in patch form, don’t have a tattoo, and have never been anywhere near a BB-gun, an actual gun, or an explosion, then – good news! – you’re probably fine. If you don’t have any metal in/on your body, the magnet is harmless.
If you have had any of the above, read on to make sure you can safely complete your scan.
The key question is what, exactly, you have under your skin. Not all metal interacts with magnets. Websites like MRIsafety provide a comprehensive list of devices and implants, but here’s the bottom line on major categories:
Medical Devices / Implants
In most cases, an MRI exam is safe for patients with metal implants, except for a few types. People with the following implants may not be scanned and should not enter the MRI scanning area without first being evaluated for safety:
- some cochlear (ear) implants
- some types of clips used for brain aneurysms
- some types of metal coils placed within blood vessels
- some older cardiac defibrillators and pacemakers
Some medication patches (including nicotine, scopolamine, and clonidine) contain metal that can heat up during a scan and even cause a burn. If you wear a patch, remove it before your scan and reapply afterward.
Some tattoo pigments contain metals, which can heat up and potentially even cause burns during a scan. With that being said, most tattoos don’t cause any issues at all. It’s usually best to try to complete your scan, stopping right away if you experience any pain or heating at the tattoo site. Covering up your tattoo is not helpful since it doesn’t block the magnetic forces at all.
Bullets and Shrapnel
Maybe you’re a combat veteran, or maybe you just played with BB guns as a kid. Either way, if you have shrapnel under your skin, it can move around and injure adjacent organs. You should probably stick with another type of imaging, like a CT scan (also known as CAT scan).
As a final note, make sure you discuss all metal implants with the radiology team, even if you think they’re safe. Also, even if you have an implant designated as “safe,” lower-strength magnets (1.5 Tesla or below) are likely the best choice.
(Featured photos courtesy of 1 and 2. Used with permission.)
To book a scan, visit us at Medmo.com. Medmo helps people schedule radiology imaging tests – such as MRI, CT scans, PET, and more – at nearby accredited centers and identify the payment solution that works best for them.