Head and Neck Imaging

Modiolus anomalies

The modiolus is the central bony axis about which the spiral canal of the cochlea winds two and a half times. A normal modiolus is identifiable as such on thin-section (1 mm thick or less) CT images and thin-section T2-weighted MR images through the inner ear; on a mid-modiolar section it appears as a bony (relatively low intensity) structure with a rectangular, triangular or trapezoidal shape. Modiolar anomalies range from some degree of deficit to complete radiological deficit (large vestibular aqueduct syndrome (VI:2), Fig. 1). Modiolar deficiency is a common feature in malformed cochleas, but is also occurs by itself; it probably represents the mildest form of cochlear dysplasia. Also, see large vestibular aqueduct syndrome.

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