Compatible with MRI imaging
MRI examination is increasingly used in medical diagnostics, most notably for injuries, chronic illness and diseases that are ever more prevalent in an ageing population. As MRI technology evolves, it is anticipated that, as well as widespread use amongst older patients, young people today should expect to undergo MRI at least once during the course of their lifetime1.
Experts agree that wearing a cochlear implant should not unduly restrict access to this potentially life-saving technology. Since its introduction, MRI has seen a significant increase in the magnetic field strength of mainstream MRI equipment. Almost three quarters of MRI scanners in use today are 1.5 Tesla (1.5T) or above, with 3.0T growing in popularity2. Future innovation involves increasing magnetic field o enable imaging resolutions and scan speeds.
At Cochlear, we design our implants with the future in mind. That’s why all our implants are safe for MRI up to 1.5T with the magnet in place and have the option of magnet removal to improve image quality if necessary. Cochlear implants from Cochlear with magnet removed are the only implant available that is safe for MRI up to 3.0T.
Frequently asked questions
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How does MRI work?
MRI works by ‘resonating’ high frequency magnetic signals through your body and creating an image as these are measured. The image appears different for different parts of your body, such as bone, muscle, fat or soft tissue. In higher resolution MRI, it’s even possible to see clearly different blood vessels or parts of the internal organs.
How is MRI affected by my CI?
Your CI will show up in an MRI scan, just like any other metallic implant, such as a joint replacement. However, because MRI uses a magnetic field, placing another magnet in close proximity to the MRI scanner creates a distortion of the magnetic field, which makes the resulting image less clear. Depending on the strength of the magnetic field, the magnet in your implant can create a blank area where the image cannot be seen at all. This may not be a problem if, for example, you need an MRI on your leg. However, if you need an MRI of your brain, it is important to be able to remove the magnet in order to gain the full benefit of the MRI.
When is it necessary to have my CI magnet removed for MRI?
Whether or not you need to have the magnet removed will depend on the strength of the MRI equipment, the type of CI you are wearing and the area of your body being scanned. In many cases, magnet removal will not be necessary. At Cochlear, we have designed all our CIs to be safe without magnet removal for MRI up to 1.5 Tesla (1.5T), but your specialist may still ask you to have your CI magnet removed depending on the purpose and area of the MRI.
Higher resolution, faster MRI equipment uses a stronger magnetic field, which can de-magnetise your CI magnet. However, this does not prevent you having this type of MRI. Cochlear® CI24RE series implants with the magnet removed are safe up to 3.0 Tesla (3.0T).
What is involved in having the magnet removed?
Removing (and then later replacing) the magnet from your CI is a minor surgical procedure requiring a small incision and can usually be carried out with a local anaesthetic. Cochlear implants are designed with this procedure in mind, so it’s fast and easy for the surgeon to access the magnet without risk of damage to your Cochlear Nucleus implant. After your MRI, a new, sterile magnet is inserted and the small wound is allowed to heal.
Can I still use my CI without the magnet?
Yes you are able to continue to use your CI with magnet removed. The magnet is used to hold the coil in place to provide power and signals to the implant. With the magnet removed an alternative method of holding the coil in place will be provided by your clinician.
Nucleus CI24RE Implant
Nucleus CI24RE Series cochlear implants are designed to work in synergy with the human cochlea.