Appearance of Congenital Inner Ear Malformations by Multi Slice Spiral CT

Objective To discuss the multi slice CT(MSCT) appearance of the congenital inner ear malformations.Materials and Methods The MSCT appearance of 17 cases with inner ear malformations were reviewed retrospectively. The axial images of interested ears and multi-planar reconstruction were performed in each patient, the affected ear were done with magnified overlap recontruction, and the 3D reconstructions of inner ear labrinth were done with volume rendering technique.Results According to the results of common malformations were (1) Michel deformity (1 ear): There was complete absence of all cochlear and vestibular structures. (2) Common cavity deformity (2 ears): There was a cystic cavity representing the cochlea and vestibule, but without showing any differentiation into cochela and vestibule. (3) In complete partition Ⅰ (3 ears): The cochlea was lacking the entire modiolus and cribriform area, resulting in a cystic appearance. This was accompanited by a large cystic vestibule. (4) In complete partition Ⅱ (Mondini deformity)(4 ears): The cochlea consisits of 1.5 turns, in which the middle and apical turns coalesce to form a cystic apex, accompanied by a dilated vestibule and enlarged VA. (5) Vestibular and semicircular canal malformaitions (14 ears): The cochlea is normal. Vestibule and the Lateral semicircular canal coalesce of the latter is small. (6) Vestibule aqueduct dilate (14 ears, of which 6 ears accompanied by other malformations): The dimension of the midisthmus of VA was more than 1.5mm. (7) Internal auditory canal malformations (all of 8 ears accompanied by other malformations): The internal auditory canal was absent, narrowed or dilated.Conclusion The congenital inner ear malformations have a special CT appearance in axial and 3D images. MSCT and the 3D reconstruction can provide a more clear and three dimensional view of the inner ear malformations, which is very useful to the diagnosis of the congenital inner ear malformations.