Role of diagnostic imaging in evaluation of cochlear implant candidate

Background: Preoperative imaging evaluation is crucial for successful cochlear implantation (CI). This study aimed to systematically identify congenital and acquired inner ear abnormalities, evaluate cochlear nerve anomalies, and detect temporal bone variations requiring surgical modifications during CI.Methods: A prospective study was conducted on 100 CI candidates with severe to profound sensorineural hearing loss at our hospital, during 2024. All patients underwent high-resolution MSCT and MRI. Cochlear parameters, including duct length and height, were measured using software-based methods. Results: The radiological assessment revealed identical findings between CT and MRI for cochlear development, with 85% showing well-developed structures and 15% presenting maldevelopment. Among malformed cases, incomplete partition type II was most prevalent (46.67%). Cochlear patency evaluation showed a patent cochlea in 97% of cases. The mean cochlear duct length was approximately 31.2mm bilaterally. MRI evaluation of the cochlear nerve demonstrated normal morphology in 95% of cases. The internal auditory canal was normal in 99% of cases, while the vestibular aqueduct was normal in 86%, dilated in 13%, and absent bilaterally in 1% of cases. Both imaging modalities showed consistent findings across all measured parameters, with superior MRI regarding cochlear nerve evaluation.Conclusions: Combined CT and MRI provide complementary information crucial for preoperative evaluation of CI candidates, enabling detailed assessment of temporal bone anatomy, inner ear malformations, and neural integrity, essential for optimal surgical planning and outcome prediction.