Fig. 4.

A Sagittal T2-weighted image in a child with Crouzon syndrome showing in the internal acoustic meatus a single dark dot (short white arrow; i.e., a single cranial nerve) presumably corresponding to the sole facial nerve due to vestibulocochlear nerve aplasia (or less likely to a fusion of seventh and eighth cranial nerves). B Sagittal T2-weighted image in a normal subject showing four dots in the internal acoustic meatus corresponding to the facial nerve and the cochlear, superior vestibular and inferior vestibular branches of the vestibulocochlear nerve. Partially reproduced from Valeggia et al. [73], with permission from Springer Nature (www.springernature.com)