General precautions and warnings
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Magnetic Resonance Imaging (MRI)
The following section applies to the SYNCHRONY cochlear implant only. It does not apply
to the SYNCHRONY ABI auditory brainstem implant
MRI CAUTION
Evidence has been provided for this implant type to pose no known hazard in specifi ed
MRI environments (without surgical removal of the internal magnet) when adhering to the
conditions and Safety Guidelines listed below. The implant has a specially designed magnet
which allows safe MRI scanning with the magnet in place, and there is no need to remove
the implant magnet regardless of the scanner fi eld strength. The implant magnet can be
surgically removed if needed to avoid imaging artefacts. The physician/MRI operator should
always be informed that a patient is a cochlear implant user and that special safety guidelines
have to be followed.
MRI scanning is possible in consideration of the Safety Guidelines if the following
conditions are fulfi lled:
• MRI scanners with static magnetic fields of 0.2 T, 1.0 T, 1.5 T or 3.0 T only. No other field
strengths are allowed. When using other field strengths, injury to the patient and/or
damage to the implant are possible.
• In case of additional implants, e.g. a hearing implant in the other ear: MRI safety
guidelines for this additional implant need to be met as well.
Safety Guidelines:
• Before patients enter any MRI room all external components of the implant system
(audio processor and accessories) must be removed from the head. For field strengths
of 1.0 T, 1.5 T and 3.0 T, a supportive head bandage must be placed over the implant. A
supportive head bandage may be an elastic bandage wrapped tightly around the head at
least three times (refer to Fig. A). The bandage shall fit tightly but should not cause pain.
Performing an MRI without head bandage could result in pain in the implant area and in
worst case can lead to migration of the implant and/or dislocation of the implant magnet.
• Head orientation: In case of 1.0 T, 1.5 T and 3.0 T MRI systems, straight head orientation
is required. The patient should not incline his/her head to the side; otherwise torque is
exerted onto the implant magnet which could cause pain. In case of 0.2 T scanners, no
specific head orientation is required.
• For 0.2 T, 1.0 T and 1.5 T scans sequences in Normal Operating Mode shall be used only.
For 3.0 T scans the SAR limit must not exceed 1.6 W/kg to avoid any potentially dangerous
heating at the electrode contacts. For the same reason head transmit coils or multi-
channel transmit coils must not be used in case of a 3.0 T MRI.
• During the scan patients might perceive auditory sensations such as clicking or beeping.
Adequate counselling of the patient is advised prior to performing the MRI. The likelihood
