MRI and medical considerations

MRI for Cochlear™ Nucleus® Systems

Cochlear implants are approved as “MR Conditional” because they contain an internal magnet. This means there are certain instructions that must be followed to ensure a safe MRI scan.^1-3 For decades, Cochlear has designed Nucleus Implants with the magnet accessible to help if an MRI is required. In cases where an MRI of the head or neck is needed, the magnet may need to be removed for the MRI to render accurately.

One of our earliest implants, the Nucleus 22 (CI22M) which is no longer being implanted, has two versions. One with a removable magnet and one without. In either case, specific instructions must be followed for the MRI to proceed. ^1-3

Cochlear Nucleus Profile^™ Plus, the latest implant offering, provides access to MRI at 1.5T and 3T with magnet in place. The Profile and CI24RE implants do not require magnet removal at 1.5T if an MRI Kit is applied. The magnet needs to be removed at 3T only for these two generations of devices. Older implant generations have varying MRI access based on the specific implant type.

As a cochlear implant recipient, there are specific considerations that need to be taken if a MRI is required. The steps are as follows:

1. Ensure your radiology center is aware that you have a cochlear implant(s) and certain conditions need to be followed for successful scans.
2. To obtain a successful MRI, the following items will be required. Please provide the following information to your radiology center, if they don't have this information.
   • Implant Model Number: The exact model(s) of your Nucleus implant will be required in order to understand the specific MRI conditions that apply. To find the implant type:
     • Log in to your Cochlear Family account and click "Equipment". You can also find your implant model number using the Nucleus Smart App by clicking "Settings" and then "About".
     • If you do not have a Cochlear Family account, you can register here.
     • Once you have your implant model number and serial number, consider putting it on your implant identification card. This card was provided at time of your surgery or may be accessed here.
     • If you are unable to register with Cochlear Family, contact Cochlear at 1-866-210-9217.
   • MRI Guidelines: The specific implant conditions are outlined within the MRI Guidelines here.

For professionals seeking further clarity on implant generations and MRI conditions, please click here.

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MRI for Cochlear Baha® Systems

For the Baha Connect System, as long as the sound processor is removed, you can have MRI scans at 1.5T and 3T.

For the Baha Attract System, an MRI can be performed at 1.5T with the magnet in place. If a 3T strength image is required required, the internal magnet can be surgically removed.

Prior to receiving an MRI, please consult with your clinician about proper precautions.

For professionals seeking more information on performing a MRI on a Cochlear Baha Implant recipient, please click here.

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MRI for Cochlear Osia® Systems

Osia was designed with the same technology that has allowed for conditional access to MRI for over two decades in Cochlear Nucleus Implant recipients. This key design feature allows for easy access and removal of the magnet.

The Osia OSI200 implant is MRI conditional for 1.5T with the MRI Kit applied and at 3T with the magnet surgically removed. The Osia OSI300 implant provides access to MRI at 1.5T and 3T with the magnet in place.

For professionals seeking more information on performing a MRI on a Cochlear Osia recipient, please click here.

MRI for Cochlear™ Vistafix® System

As long as the Vistafix prosthesis, bar construction, any fixation magnets, magnabutments or magnacaps are removed for the MRI procedure, a patient fitted with a Vistafix System may be exposed to an MRI examination. When undergoing an MRI, the following conditions apply.

MRI Safety information

The prosthesis, the bar construction, any fixation magnets, magnabutments or magnacaps attached to the implants must be removed before entering a room where an MRI scanner is located.

Non-clinical testing has demonstrated that Vistafix implants, cover screws, and abutments are MR Conditional at 1.5 and 3T. They can be scanned safely under the following conditions. Scanning under other conditions may result in severe patient injury or device malfunction.

• Static magnetic field of 1.5T and 3T only
• Maximum spatial gradient field of 3000 Gauss/cm (30 T/m)
• Maximum MR System reported whole body averaged specific absorption rate (SAR) of 2 W/kg or maximum head averaged SAR of 3.2 W/kg (Normal Operating Mode)

Under the scan conditions defined above, the implant, cover screw, abutment, and healing cap are expected to produce a maximum temperature rise of 1.1 °C after 15 minutes of continuous scanning.

In non-clinical testing with the implant and abutment in place, the image artifact caused by the device extends approximately 1.8 cm from the implant and abutment when imaged with a gradient echo pulse sequence and a 3T MRI system. The artifact is reduced to 1.2 cm from the implant when the abutment is removed.

For professionals seeking more information on performing an MRI on a Cochlear VistaFix recipient please click here.

 

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