The FDA advises patients, caregivers, healthcare providers, and MR technologists to be aware of the risks that an MRI may pose to patients with cochlear implants, take precautions to avoid these risks, and report any adverse events that may occur in the MRI environment.
On this page:
- MRIs and Implants Containing Metal or Magnets
- Cochlear Implant Patient Implant Card
- Cochlear Implants and MRI Safety
- Adverse Events Associated with Cochlear Implants and MRIs
- Recommendations for Patients and Caregivers
- Recommendations for Health Care Providers and MR Technologists
- Reporting Adverse Events with Cochlear Implants
Magnetic Resonance Imaging (MRI) is a medical imaging procedure for making images of the internal structures of the body. MRI scanners use strong magnetic fields and radio waves (radiofrequency energy) to make images.
The strong magnetic field of an MRI scanner can affect medical implants that contain metal or magnets. When this happens, the implant may move or twist inside of the patient’s body, causing discomfort, pain, or injury. Patients with metal-containing implants such as cochlear implants (which also typically contain a magnet) need to be aware of this risk and ensure that health care providers and MR technologists are aware of their implant so that they can take proper precautions when receiving an MRI exam. In addition, the radio waves of an MRI scanner may cause heating of the implant.
Following surgical placement of a cochlear implant, the patient or caregiver receives an implant card like the example below for a hypothetical MR Conditional implant. This card has important information about the implant and MRI safety.
Each type of cochlear implant has specific recommendations for undergoing MRI exams. Health care providers and MR technologists should always follow the cochlear implant manufacturer’s recommendations and instructions for use.
Cochlear implants have different types of ratings for MRI safety.
- MR Unsafe means that a patient with that type of implant should not receive an MRI exam while they have the implant.
- MR Conditional means the patient can have an MRI exam under certain specific conditions.
For example, some newer cochlear implants that are MR Conditional are designed to allow the implant magnet to turn and reorient in place. The reorienting of the magnet within the cochlear implant reduces the twisting forces on the implant and surrounding tissue when exposed to the magnetic field of the MRI scanner.
Some MR Conditional cochlear implants may require the magnet to be surgically removed before an MRI can take place. The magnet will need to be surgically replaced following the MRI procedure.
For other MR Conditional cochlear implants, splint/bandaging kits may be available from the manufacturer for use during MRI. If these kits are used, it is important to use the kit designed for the cochlear implant and to follow manufacturer instructions.
When a patient with a cochlear implant receives an MRI exam, there is potential for adverse events to occur. Adverse events can include:
- Pain during or after the scan
- Skin swelling or breakdown over implant magnet
- Surgical procedure to reposition or replace the implant magnet after the scan
- Surgical procedure to replace the cochlear implant because the device failed after the scan
- Infection after a surgical procedure for one of the reasons above
How often these types of events occur is unknown and depends on the cochlear implant, the surgical placement, and the MR procedures used for the scan.
- Know the brand and model of the cochlear implant.
- Always carry the implant card you were given with you. If you do not have an implant card, contact the manufacturer to obtain one.
- If you need an MRI, tell the health care provider and the MR technologist about your implant and share the information on the implant card.
- Follow the MRI instructions provided by the manufacturer of the patient’s cochlear implant. Ensure that the static magnetic field strength (for example, 0.2T, 1.5T, 3.0T) of the scanner is compatible with the implant. Some cochlear implants require the surgical removal of the magnet before the scan, and magnet replacement after the scan. Other cochlear implants may not require magnet removal, but have specific MRI instructions that should be followed. Instructions may be included in device labeling, posted on the manufacturer’s website, or both.
- Consider other types of imaging, if clinically appropriate.
- For MR Conditional cochlear implants that are used with splint/bandaging kits, only use the FDA-approved splint/bandaging kits designed to be used with the patient’s specific cochlear implant. Follow the manufacturer’s instructions for use. Do not use other bandaging that is not intended for this purpose.
- There are some magnet-containing implants for hearing impairment that are not cochlear implants. Examples include bone-anchored or bone conduction hearing aids or middle ear implants. Follow the manufacturer’s instructions for use.
Report any adverse events associated with MRI and cochlear implants. Reporting these events can help the FDA identify and better understand the risks related to the use of medical devices.
If you suspect or experience a problem with cochlear implants or accessories during MRI, file a voluntary report through MedWatch, the FDA Safety Information and Adverse Event Reporting program. Health care personnel employed by facilities that are subject to the FDA's user facility reporting requirements should follow the reporting procedures established by their facilities.