Computed Tomography and Magnetic Resonance Imaging for Congenital Hearing Loss: A Retrospective Study.

Objective: The aim of this study is to evaluate the relationship between the cochlear nerve and the anatomical structures of the cochlea and internal acoustic canal in patients with congenital hearing loss.

Materials and methods: Temporal tomography and magnetic resonance images of 44 patients (88 ears) with non-syndromic congenital hearing loss were retrospectively analyzed between 2018 and 2021. Patients were divided into 2 groups according to cochlear nerve hypoplasia. Cochlear nerve canal width, cochlear basal/ middle turn widths, and internal auditory canal widths were examined.

Results: Cochlear nerve hypoplasia was detected in 18.2% (n=16) of the patients and all of the patients with cochlear nerve hypoplasia had severe hearing loss. A statistically significant difference was found between the structures' widths in patients with and without cochlear nerve hypoplasia, in cochlear nerve canal and coronal width of the internal auditory canal. When stenosis is accepted as <1.4 mm for cochlear nerve canal and <3.80 mm for coronal width of the internal auditory canal, cochlear nerve hypoplasia differs statistically between the groups in measurements (respectively; P < .001, P=.018).

Conclusions: In patients with sensorineural hearing loss, cochlear nerve hypoplasia may accompany. Anatomical structures are important in predicting cochlear nerve hypoplasia from temporal computed tomography. Cochlear nerve hypoplasia should be suspected if the cochlear nerve canal and coronal width of the internal auditory canal are less than 1.4 mm and 3.8 mm, respectively, on temporal computed tomography.