Magnetic resonance imaging (MRI) is very safe and most people can have the procedure, including pregnant women and babies.
However, there are some instances where an MRI scan may not be recommended, because the strong magnets used during the scan can affect any metal implants or fragments in your body.
Before having an MRI scan, you should tell medical staff if:
you think you have any metal in your body
you’re pregnant or breastfeeding
There’s no evidence to suggest MRI scans pose a risk during pregnancy. However, as a precaution, MRI scans aren’t usually recommended during pregnancy, particularly in the first three months.
Metal implants or fragments
Having something metallic in your body doesn’t necessarily mean you can’t have an MRI scan, but it’s important for medical staff carrying out the scan to be aware of it.
They can decide on a case-by-case basis if there are any risks, or if further measures need to be taken to ensure the scan is as safe as possible. For example, it may be possible to make a pacemaker or defibrillator MRI-safe, or to monitor your heart rhythm during the procedure.
If you’re unsure about any metal fragments in your body, you may need an X-ray
Some examples of metal implants or fragments include:
a pacemaker www.nhs.uk – an electrical device used to control an irregular heartbeat
an implantable cardioverter-defibrillator (ICD) –a similar device to a pacemaker that uses electrical shocks to regulate heartbeats
metal plates, wires, screws or rods – used during surgery for bone fractures
a nerve stimulator –an electrical implant used to treat long-term nerve pain
a cochlear implant –a device similar to a hearing aid that’s surgically implanted inside the ear
a drug pump implant –used to treat long-term pain by delivering painkilling medication directly to an area of the body, such as the lower back
brain aneurysm clips –small metal clips used to seal blood vessels in the brain that would otherwise be at risk of rupturing (bursting)
metallic fragments in or near your eyes or blood vessels (common in people who do welding or metalwork for a living)
prosthetic (artificial) metal heart valves
penile implants –used to treat erectile dysfunction (impotence)
eye implants –such as small metal clips used to hold the retina in place
an intrauterine device (IUD) www.nhs.uk –a contraceptive device made of plastic and copper that fits inside the womb
artificial joints – such as those used for a hip replacement www.nhs.uk or knee replacement www.nhs.uk
dental fillings and bridges
tubal ligation clips –used in female sterilization www.nhs.uk
surgical clips or staples – used to close wounds after an operation
Some tattoo ink contains traces of metal, but most tattoos are safe in an MRI scanner. Tell the radiographer immediately if you feel any discomfort or heat in your tattoo during the scan.