The new classification system for inner ear malformations: the INCAV system.

CONCLUSIONS: The proposed INCAV system standardizes reporting of inner ear malformations; gives adequate information about the structures of inner ear; defines the ears which could not be classified before; and helps in the selection of the ear as the cochlear implant candidate. Also it is easy-to-use for radiologists, and useful to the referring otolaryngologists.

OBJECTIVE: This study was conducted to explore a more specific, definitive classification system which was based on radiological criteria for inner ear malformations.

METHOD: This study found 43 patients who had inner ear malformations, magnetic resonance (MR), and computed tomography (CT) imaging, together with the retrospective evaluation of the medical records between August 2010 and February 2015. It analyzed inner ear structures by dividing five sub-groups and each sub-group was given a letter: internal acoustic canal (I), cochlear nerve (N), cochlea (C), vestibular aqueduct (A) and vestibule (V). Based on their malformations, these anatomical structures have been assigned grades and have been classified by using increasing numbers which were dependent to increasing order of severity of the malformation.

RESULTS: Among these 43 patients, there were six normal (I0 N0 C0 A0 V0 ) and 80 inner ear malformations. All of the ears were defined successfully by the INCAV system.