Absent Semicircular Canals in CHARGE Syndrome: Radiologic Spectrum of Findings
A.K. Morimotoa,
R.H. Wiggins, IIIa,
P.A. Hudginsb,
G.L. Hedlundc,
B. Hamiltona,
S.K. Mukherjid,
S.A. Teliane and
H.R. Harnsbergera
a Department of Radiology, University of Utah Health Sciences Center, Salt Lake City, Utah
b Department of Radiology, Emory University, Atlanta, Ga
c Primary Childrens Medical Center, Salt Lake City, Utah
d Departments of Radiology, University of Michigan Health System, Ann Arbor, Mich
e Otolaryngology–Head and Neck Surgery, University of Michigan Health System, Ann Arbor, Mich
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Fig. 1. Axial CT at the level of the cochlea demonstrates cochlear aperture atresia or trapped cochlea. The modiolus is dysplastic as well. Left, there is ossification over the cochlear aperture (black arrow), which is normally widely patent and occupied by the cochlear nerve (right).
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Fig. 2. Axial CT of the cochlea. Left: Dysplastic posterior strut of the modiolus (black arrows) with lack of the normally ossified crown-like structure seen on the right.
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Fig. 3. Three axial CT images at the level of the cochlea demonstrating examples of cochlea that are amorphous and lack definable turns, internal septation, or a modiolus. The lower 2 cases demonstrate gross hypoplasia.
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Fig. 4. Axial CT of the cochlea. Left, Apical turn hypoplasia. Right: Normal cochlea.
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Fig. 5. Axial images at the level of the vestibule. Top, Bilateral absent semicircular canals with isolated vestibules. Bottom, Normally formed semicircular canals.
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Fig. 6. Axial CT at the level of the vestibule. The black arrow points to a dysplastic vestibule. The middle ear cavity is small and nonpneumatized, and the head of the malleus is ankylosed to the anterior epitympanic wall.
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Fig. 7. Axial CT images of the middle ear. Left, Small middle ear cavity in patient with CHARGE syndrome with ankylosis of the dysplastic ossicles to each other and to the epitympanic wall. Right, Normal middle ear cavity.
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Fig. 8. Axial CT at the level of the round window. Left, The black arrow points to the small round window. The middle ear cavity is also hypoplastic. Right, Normal round window.
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Fig. 9. Coronal CT at the oval window. Left, The black arrow points to a bony bar at the expected location of the normal membranous oval window. There is a prolapsed tympanic segment of the facial nerve (white arrow). Right, Normal oval window (double white arrow) and tympanic segment of the facial nerve (white arrow).
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Fig. 10. Axial CT at the level of the internal auditory canal. Abnormal course of facial nerve labyrinthine segment. Left, Arrow shows posteriorly bowing labyrinthine segment of the facial nerve. Right, Normal labyrinthine segment is straight and overlies a portion of the cochlea.
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Fig. 11. Three axial CT images demonstrating examples of petrosquamosal sinuses (white arrows), a form of emissary vein anomaly.
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Fig. 12. Oblique sagittal T2-weighted images that demonstrate lack of a normal-appearing cochlear nerve (white arrow) in the 2 left images. The third image demonstrates a normal-appearing 4-nerve bundle of facial, cochlear (open arrow), and vestibular nerves.
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