Bionic ear imaging.
OBJECTIVE
The aim of this study was to illustrate the different imaging features of middle and inner ear implants, brainstem implants and inferior colliculus implants.


METHODS
We retrospectively reviewed the computed tomography (CT) images of 468 patients with congenital or acquired transmissive or neurosensory hearing loss who underwent surgery. The implants examined were: 22 Vibrant Soundbridge implants, 5 at the long limb of the incus and 17 at the round window, 350 cochlear implants, 95 brainstem implants and 1 implant at the inferior colliculus. All patients underwent a postoperative CT scan (single or multislice scanner) and/or a Dentomaxillofacial cone-beam CT scan (CBCT) (axial and multiplanar reconstruction), and/or a plain-film radiography to visualise the correct position of the implant.


RESULTS
The CBCT scan depicts Vibrant site of implant better than plain-film radiography, with a lower radiation dose compared to CT. For cochlear implants, a single plain radiograph in the Stenvers projection can directly visualise the electrodes in the cochlea. All patients with brainstem or inferior colliculus implants underwent postoperative CT to exclude complications and the assess correct implantation, but the follow-up of these implants can be performed by plain radiography alone.


CONCLUSIONS
CT and CBCT scans are reliable and relatively fast methods for precisely determining the location of middle ear implants. CBCT is preferable to CT because of the lower radiation dose administered; a single plain-film radiograph is enough to visualise and follow-up cochlear, brainstem and inferior colliculus implants.
Cerini
R
R
Istituto di Radiologia, Università di Verona, Piazzale L.A. Scuro, Verona, Italy. roberto.cerini@azosp.vr.it
Faccioli
N
N
Barillari
M
M
De Iorio
M
M
Carner
M
M
Colletti
V
V
Pozzi Mucelli
R
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D038262:Auditory Brain Stem Implants; D001701:Bionics; D002648:Child; D002675:Child, Preschool; D003054:Cochlear Implants; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D007758:Ear, Inner / Q000000981:diagnostic imaging* / Q000601:surgery; D004432:Ear, Middle / Q000000981:diagnostic imaging* / Q000601:surgery; D004567:Electrodes, Implanted; D034381:Hearing Loss / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007223:Infant; D007245:Inferior Colliculi / Q000000981:diagnostic imaging; D008875:Middle Aged; D009998:Ossicular Prosthesis; D011184:Postoperative Period; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods