Clinical and Quantitative Radiologic Evaluation of Cochlear Implant Candidates: Implications for Surgical Planning

The authors' aim was to evaluate the clinical and quantitative radiologic characteristics of cochlear implant candidates and to examine the contribution of standardizing measurements to preoperative evaluation and surgical planning. In the authors' study, the data of 74 patients who underwent cochlear implants in our clinic were analyzed retrospectively. All patients underwent preoperative high-resolution temporal bone computed tomography (HRCT) and inner ear magnetic resonance imaging (MRI). Quantitative radiologic measurements included cochlear basal turn length and height, overall cochlear height, cochlear aperture width, vestibular and cochlear aqueduct diameters, internal auditory canal (IAC) width, vestibular diameter, and cochlear nerve diameter. Temporal bone anatomic variations and mastoid pneumatization patterns were also evaluated. Child and adult groups were compared, and statistical analysis was performed on quantitative radiologic parameters. Significant differences were observed between pediatric and adult patients for several quantitative parameters. Adults demonstrated significantly larger cochlear aqueduct diameter, vestibular aqueduct diameter, cochlear aperture width, cochlear height, and IAC width (P<0.05), whereas basal turn length and height did not differ significantly. In pediatric patients, cochlear aperture width showed a significant positive correlation with IAC diameter (r=0.395, P = 0.003). MRI-based analysis revealed a significant positive correlation between cochlear nerve diameter and IAC diameter in pediatric patients (r=0.575, P<0.001), whereas no significant correlations were identified in adults. Cochlear malformations were detected in 8 ears. The overall complication rate was 10%. Clinical and radiologic evaluation is very important in the selection of cochlear implant candidates. Making radiologic data, especially with quantitative measurements, is important in terms of establishing standard evaluation protocols for patients. The patient's clinical and radiologic information is a guide in follow-up and treatment, and is data that can increase the patient's benefit from the implant.