A high-resolution computed tomography based scoring system to predict ease of electrode insertion in cochlear implantation

Objective This study aimed to formulate a scoring system based on high-resolution computed tomography scans to predict ease of electrode insertion during cochlear implantation via posterior tympanotomy in paediatric patients. Method A scoring system Cochlear Implantation Radiological Assessment Score (CIRAS) was formulated based on six parameters. This score was correlated with intra-operative findings, and receiver operating characteristic analysis was performed to determine the optimal cut-off score to predict difficulty of surgery and to establish the inherent validity of the scoring system by area under curve. Results Receiver operating characteristic analysis showed that optimal cut-off score was 8 (93.1 per cent specificity and 56.52 per cent sensitivity), and area under the curve was 0.828. Patients with CIRAS of more than 8 had significantly higher time for surgery (p < 0.05). Conclusion CIRAS is an easy to administer tool by utilising classical axial and coronal sections, without any numerical measures. Pre-operative assessment by this score gives a good idea of intra-operative challenges.