MRI Safety Information

Do not allow patients with a HiRes Ultra cochlear implant to be in the area of an MRI scanner unless the following conditions have been met:

• The bandaging protocol [Refer to the MRI Antenna Coil Cover (CI-7521) IFU for details] recommended by Advanced Bionics is followed when the patient undergoes an MRI procedure with the magnet left in place, or
• For cases that would clinically benefit from reduced device artifact (for example some head or neck scans), the internal magnet is surgically removed and possibly replaced with the temporary nonmagnetic plug before the patient undergoes an MRI procedure.
• The external sound processor and headpiece are MR Unsafe and must be removed before entering a room containing an MR scanner.
   

The recommended minimum duration of time post implant surgery prior to undergoing an MRI scan is 2 to 4 weeks in order to allow any inflammation to subside.

An MRI scan is not recommended if the patient has a fever.

For additional information regarding the use of an MRI scanner with a HiRes Ultra device, please contact Advanced Bionics Technical Support.

• Horizontal closed bore scanners with a static magnetic field of 1.5T (magnet in place).
• Maximum MR system reported, whole body averaged specific absorption rate (SAR) of ≤ 2.0 W/kg at 1.5T for quadrature transmit RF body coils.
• Maximum MR system reported, head averaged SAR of ≤ 3.2 W/kg at 1.5T for quadrature transmit RF head coils.
• RMS gradient field of 30 T/s and peak gradient field of 150 T/s.
• Maximum spatial field gradient of 3.47 T/m at 1.5T with the magnet in place.

When tested under the scan conditions defined above the HiRes Ultra implant produced a maximum temperature of < 3° after 15 minutes of continuous 1.5T Scanning.

In MRI testing of unilateral recipient conditions, the image artifact caused by the device extends from the HiRes Ultra implant approximately 7.9 cm in a 1.5T MRI with the magnet in place and In MRI testing of bilateral recipient conditions >9.5 cm in a 1.5T MRI with the magnet in place using a spin echo or gradient echo pulse sequence.

These artifacts may result in a loss of diagnostic information in the implant vicinity.

Please note that the MRI Antenna Coil Cover CI-7521 and bandaging supplies must be on hand at the time of the MRI procedure.

Testing has demonstrated that the HiRes 90K™ cochlear implant family is MR Conditional. Unilateral and bilateral recipients with this device can be safely scanned in an MR system meeting the following conditions:

• Maximum MR system reported, whole body averaged specific absorption rate (SAR) of ≤ 1.7 W/kg at 1.5T for quadrature transmit RF body coils
  
• Maximum MR system reported, head averaged SAR of ≤ 1 W/kg at 1.5T for quadrature transmit RF head coils
  
• RMS gradient field of 30 T/s and peak gradient field of 150 T/s
  
• Maximum spatial field gradient of 2.5 T/m at 1.5T with the magnet in place and 2.5 T/m at 1.5T with the magnet removed.
  

When tested under the scan conditions defined above with the patient’s head in the center of the MR scanner, the HiRes 90K Advantage implant produced a maximum temperature rise of <2.4°C after 15 minutes of continuous scanning when using a body coil and whole body averaged SAR of 1.7 W/kg.

In MRI testing of unilateral recipient conditions, the image artifact caused by the device extends from the HiRes 90K Advantage implant:

• Approximately 6 cm in a 1.5T MRI with the temporary non-magnetic plug in place using a gradient echo pulse sequence

These artifacts may result in a loss of diagnostic information in the implant vicinity.

Do not allow patients with a HiRes 90K/Advantage cochlear implant to be in the area of an MRI scanner unless the following conditions have been met:

• The bandaging protocol recommended by Advanced Bionics is followed when the patient undergoes a 1.5T MRI procedure with the magnet left in place, or
• For cases that would clinically benefit from reduced device artifact (for example some head or neck scans), the internal magnet is surgically removed and possibly replaced with the temporary non-magnetic plug before the patient undergoes an MRI procedure.
• The external sound processor and headpiece are removed before entering a room where an MRI scanner is located.
• The recommended minimum duration of time post implant surgery prior to undergoing an MRI scan is 2 to 4 weeks in order to allow any inflammation to subside.
• An MRI scan is not recommended if the patient has a fever.
   

Caution: The bandaging protocol with use of the MRI Antenna Coil Cover was developed and approved to prevent magnet displacement and counteract magnet torque during a 1.5T MRI procedure, but some discomfort and pain at the implant site may still be experienced. Please consult with your physician if this is an issue

Caution: If discomfort persists following an MRI, please notify your physician

Caution: Failure to secure the MRI Antenna Coil Cover and internal magnet in place during MRI may result in magnet displacement or the need for surgical revision

Caution: Please consult with your physician prior to MRI to determine if the benefits of MRI are worthwhile over other imaging techniques
 

• MRI preparations must be conducted outside of the MRI room.
• Verify that the implant, or both implants if bilaterally implanted, are compatible for conducting an MRI before proceeding. Failure to do so can lead to device movement, device damage, magnet movement, patient discomfort, or trauma and pain to the patient.
• MRI procedures are contraindicated for CLARION (C1 and CII) Cochlear Implant recipients.
   

For additional information regarding the use of an MRI scanner with a HiRes 90K/Advantage device, please contact Advanced Bionics Technical Support.
MRI testing of the HiRes 90K cochlear implant family with the internal magnet in place is only available in markets where regulatory approval has been received. Contact your Advanced Bionics representative for more information.