Cochlear implants (CI) are a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf or severely hard of hearing. Unlike conventional hearing aids, the cochlear implant does not amplify sound, but works by directly stimulating any functioning auditory nerves inside the cochlea with an electric field.
External components of the cochlear implant include a microphone, speech processor and an RF transducer or primary headpiece coil. A secondary coil is implanted beneath the skull's skin and inductively coupled to the primary headpiece coil.
The implant gives recipients additional auditory information, which may include sound discrimination fine enough to understand speech in quiet environments. Post-implantation rehabilitative therapy is often critical to ensuring successful outcomes.
Post operative plain film radiography of the temporal bones are sufficient in a majority of patients. Plain radiography is the most helpful modality to assess for extrusion and superior in assessing the number of inserted electrodes. Typically a modified Stenvers view is performed, which has succeeded the original Stenvers view.
Particularly useful when postoperative radiographs fail to demonstrate the location of the electrode array adequately or if postoperative infection is suspected 1.
Inner ear pathology
inner ear anatomy
- enlarged vestibular aqueduct
- semicircular canal dysplasia
- classification of cochlear anomalies
- infection and inflammation
- trauma and miscellaneous
- 1. Shpizner BA, Holliday RA, Roland JT et-al. Postoperative imaging of the multichannel cochlear implant. AJNR Am J Neuroradiol. 1995;16 (7): 1517-24. AJNR Am J Neuroradiol (abstract) - Pubmed citation
- 2. Czerny C, Steiner E, Gstoettner W et-al. Postoperative radiographic assessment of the Combi 40 cochlear implant. AJR Am J Roentgenol. 1997;169 (6): 1689-94. AJR Am J Roentgenol (abstract) - Pubmed citation
- 3. Mukherji SK, Mancuso AA, Kotzur IM et-al. CT of the temporal bone: findings after mastoidectomy, ossicular reconstruction, and cochlear implantation. AJR Am J Roentgenol. 1994;163 (6): 1467-71. AJR Am J Roentgenol (abstract) - Pubmed citation
- 4. Verbist BM, Frijns JH, Geleijns J et-al. Multisection CT as a valuable tool in the postoperative assessment of cochlear implant patients. AJNR Am J Neuroradiol. 2005;26 (2): 424-9. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 5. Jain R, Mukherji SK. Cochlear implant failure: imaging evaluation of the electrode course. Clin Radiol. 2003;58 (4): 288-93. Clin Radiol (link) - Pubmed citation