- The external sound processor and headpiece are MR Unsafe and must be removed before entering a room containing an MR scanner.
- A bandage must be applied using the bandaging protocol below.
- Horizontal closed bore scanners with a static magnetic field of 1.5T.
- Maximum spatial field gradient of 2,000 Gauss/cm (20 T/m).
- Maximum MR system reported, whole body averaged specific absorption rate (SAR) of ≤ 2 W/kg at 1.5T (Normal Operating Mode) for quadrature transmit RF body coils.
- Maximum MR system reported, head averaged SAR of ≤ 3.2 W/kg at 1.5T (Normal Operating Mode) for quadrature transmit RF head coils.
- RMS gradient field of 30 T/s and peak gradient field of 150 T/s.
Under the scan conditions defined above the HiRes Ultra implant is expected to produce a maximum temperature rise of <3°C after 15 minutes of continuous 1.5T scanning.
In MRI testing of unilateral and bilateral recipient conditions, respectively, the image artifact caused by the device extends from the HiRes Ultra implant approximately 8 cm using a gradient echo pulse sequence and >9.5 cm using a spin echo or gradient echo pulse sequence in a 1.5T scanner with the magnet in place. These artifacts may result in a loss of diagnostic information in the implant vicinity.
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.
Please note that the MRI Antenna Coil Cover CI-7521 and bandaging supplies must be on hand at the time of the MRI procedure. Please contact Advanced Bionics technical support at firstname.lastname@example.org, or 1.877.454.5051 to request the MRI Antenna Coil Cover.
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.