Preoperative temporal bone computerised tomography and magnetic resonance imagining findings in patients with congenital sensorineural hearing loss

Objective: The aim of this study is to determine and classify inner ear abnormalities in patients who had cochlear implant because of congenital sensorineural hearing loss by using preoperative temporal bone computerised tomography and magnetic resonance imaging. Material and Method: Patients who had cochlear implantation because of congenital sensorineural hearing loss between January 2011 and December 2013 in otolaryngology department were included in study. There were 167 male and 133 female patients with a sum of 300. All of the patients were evaluated with 4-detector-row Computerised Tomography and 1,5 Tesla Magnetic Resonance Imagining. Results: Inner ear abnormalities were found in 136 of 600 ears (20.3%). There were 6 ears with incomplete partition-II (4.4%), 5 ears with incomplete partition-I (3.6%), 2 ears with Michel Deformity (1.4%), 2 ears with cochlear hypoplasia (1.4%), 2 ears with cochlear otosclerosis (1.4%) and one ear with common cavity deformity (0.7%). Dilatation of internal acoustic canal was found in 42 ears (30.9%) also 21 ears with cochlear nerve aplasia/hypoplasia (15.4%), 5 ears with internal acoustic canal aplasia and 1 ear with internal acoustic canal hypoplasia (0.73%) were detected. There were 10 ears with posterior semicircular canal (7.3%), 10 ears with lateral semicircular canal (7.4%), 8 ears with süperior semisircular canal aplasia/hypoplasia (5.9%) and 8 ears with lateral semicircular canal-vestibular dysplasia. Enlarged vestibular aqueduct was found in 16 ears (11.7%). High riding jugular bulb was found in 21 ears but this variation was not considered as an inner ear abnormality. Conclusion: Computed Tomography and Magnetic Resonance Imagining are essential for evaluation of determining and classifying of inner ear abnormalities in patients with congenital sensorineural hearing loss who are planned to have cochlear implantoperation. Also these radiological instruments are helpful to determine contraindications and to predict intraoperative difficulties. Computed Tomography and Magnetic Resonance Imagining findings of these patients should be evaluated by an experienced radiologist before operation.