MR compatibility of Med EL cochlear implants: clinical testing at 1.0 T.
OBJECTIVE
Our aim was to evaluate the MR compatibility of Med EL cochlear implants by performing in vitro and in vivo tests.


METHODS
All experiments were done on a 1.0 T machine. Potential movement of the cochlear electrode relative to a scale was recorded. Potential dislodgment of the magnetic receiver coil was evaluated with the coil fixed to the retroauricular skin of a volunteer. Temperature changes were measured with temperature sensors fixed to the electrode, performing standard MR sequences. In 11 patients, MRI of the brain was performed 1 day before explantation of the devices using standard MR sequences. Testing of the auditory abilities was done before and after the examination. All explanted devices were assessed for function.


RESULTS
There was no detectable movement of the electrode or the receiver coil nor any temperature change. There were no adverse events for the patients. All 11 explanted cochlear implants retained their function.


CONCLUSIONS
Med EL cochlear implants are not a firm contraindication for MRI.
Youssefzadeh
S
S
Department of Radiology, University of Vienna, Austria.
Baumgartner
W
W
Dorffner
R
R
Gstöttner
W
W
Trattnig
S
S
D016477:Artifacts; D001301:Audiometry, Pure-Tone; D001302:Audiometry, Speech; D001921:Brain / Q000033:anatomy & histology; D003054:Cochlear Implants; D000075202:Contraindications; D004566:Electrodes; D004869:Equipment Safety; D005069:Evaluation Studies as Topic; D006358:Hot Temperature; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D008280:Magnetics; D008422:Materials Testing; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013067:Speech Perception