Hypoplasia of cochlear nerve foramen:CT findings / 中华放射学杂志

ABSTRACT

Objective To observe the CT findings of hypoplasia of cochlear nerve foramen. Methods CT findings of cochlear nerve foramen were observed in 50 volunteers (100 ears)and in 9 cases with hypoplasia of cochlear nerve foramen.The width of the bony canal for the cochlear nerve were measured in both groups.Results The fissure in the cribriform area were seen in every volunteers.The width of the bony canal for the cochlear nerve was (2.32?0.25)mm in normal group.The stenosis of cochlear nerve foramen were shown in 9 cases (10 ears),the lacking of fissure in the cribriform area were seen in 8 ears, while the fissure were shown in 2 cases.The stenosis of internal auditory canal was shown in 4 cases. Abnormality of vestibule and horizontal semicircular canal was shown in one case.The maximum value of the width of the bony canal for the cochlear nerve was 1.5mm,the minimum value was 0.9 mm.Conclusions The typical CT findings of hypoplasia of cochlear nerve foramen were stenosis of cochlear nerve foramen,the lacking of fissure in the cribriform area and cochlear nerve foramen without helix shape.The hypoplasia of cochlear nerve foramen may be a subtype of cochlear dysplasia.