Korean J Radiol.  2008 Jul;9(Suppl):S22-S25. 10.3348/kjr.2008.9.s.s22.

A Narrow Internal Auditory Canal with Duplication in a Patient with Congenital Sensorineural Hearing Loss

• Baik HW
• Yu H
• Kim KS
• Kim GH

• KMID: 1100098
• DOI: http://doi.org/10.3348/kjr.2008.9.s.s22

Abstract

A narrow internal auditory canal (IAC) with duplication is a rare anomaly of the temporal bone. It is associated with congenital sensorineural hearing loss. Aplasia or hypoplasia of the vestibulocochlear nerve may cause the hearing loss. We present an unusual case of an isolated narrow IAC with duplication that was detected by a CT scan. In this case, the IAC was divided by a bony septum into an empty stenotic inferoposterior portion and a large anterosuperior portion containing the facial nerve that was clearly delineated on MRI.

Keyword

Ear, abnormalities; Ear anatomy; Ear, MR; Magnetic resonance (MR), pulse sequences; Magnetic resonance (MR), thin section; Nerves, abnormalities

MeSH Terms

Child
Ear, Inner/*abnormalities/radiography
Female
Hearing Loss, Sensorineural/*congenital
Humans
Tomography, X-Ray Computed

Figure

• 

  Fig. 1 Narrow internal auditory canal with duplication in 6-year-old girl. A. Coronal CT image shows narrow internal auditory canal with duplication divided by bony septum into relatively large anterosuperior (arrow) and stenotic inferoposterior portions. B. Axial CT image shows same findings. Inferoposterior portion (arrow) of internal auditory canal is smaller than anterosuperior portion. C. Axial CT image shows normal contralateral internal auditory canal (arrow). D. 3D-DRIVE T2-weighted axial image of right temporal bone shows narrow internal auditory canal with duplication. E. T2-weighted fast spin echo parasagittal image of right internal auditory canal demonstrates facial nerve that fills upper canal (arrow), but vestibulocochlear nerve is not seen in lower canal (arrowhead). F. T2-weighted fast spin echo parasagittal image of left internal auditory canal demonstrates normal facial nerve (arrow), common vestibular nerve (small arrowhead), and cochlear nerve (large arrowhead).

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