Cochlear
™
Baha
®
Attract System
Radiographer’s Instructions for MRI
The Cochlear
™
Baha
®
Attract System is a magnetic bone conduction implant system. The system includes an
osseointegrated BI300 Implant and a BIM400 Implant magnet that are implanted beneath the skin. A Baha Sound
Processor and a Sound Processor
(SP)
Magnet are worn on the head
(see Fig. 1)
.
These guidelines are intended for radiologists performing MRI scans on a patient with the Cochlear Baha Attract
System. Please read this information carefully.
For more information, contact Cochlear.
MRI Safety Information
The sound processor and Sound Processor Magnet must
be removed before entering a room where an MRI scanner
is located.
Non-clinical testing has demonstrated that the
BIM400 Implant Magnet, in combination with
a BI300 Implant, is MR Conditional.
It 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 1.5 Tesla only
• Maximum spatial gradient field of 26600 Gauss/cm
(266 T/m)
• Maximum switched gradient slew rate per axis
of 200 mT/m/ms
• Maximum switched gradient amplitude per axis
of 45 mT/m
• Maximum MR System reported whole body averaged
specific absorption rate
(SAR)
of 2.0 W/kg
(Normal Operating Mode)
Additional instructions essential to safe use
in the MR environment:
Under the scan conditions defined above, the
BIM400 Implant Magnet is expected to produce a
maximum temperature rise of 2.1 °C after 15 minutes
of continuous scanning.
In non-clinical testing, the BIM400 Implant
Magnet produced a temperature rise of less than
2.1 °C
(extrapolated)
at a maximum whole body
averaged specific absorption rate
(SAR)
of 2.0 W/kg
(extrapolated)
assessed by calorimetry for 15 minutes
of MR scanning in a 1.5 Tesla Intera, Philips Medical
Systems
(Software: 12.6.1.3, 2010-12-02)
MR Scanner.
Figure 2
BI300 Implant
BIM400 Implant Magnet
Sound Processor Magnet
Baha Sound Processor
Figure 1
