FIG 1. Four contiguous axial view CT scans of the temporal bone, obtained from cephalad to caudad through the internal auditory canal and cochlea.

A, Note the normal location of the origin of the labyrinthine segment of the facial nerve (black arrowhead).

B, Note the normal sized basilar, second, and apical turns of the cochlea. Black arrow, normal modiolus.

C, Note the normal sized basilar, second, and apical turns of the cochlea. Black arrow, normal cochlea.

D, Note the normal sized basilar, second, and apical turns of the cochlea. Black arrow, normal basilar turn; open arrow, normal separation of the second and apical turns