Imaging of cochlear implants

Abstract

Abstract Aim : To evaluate the role of various imaging modalities in pre and post operative evaluation of cochlear implant candidates. Materials and methods : 30 patients were evaluated by HRCT and 15 of these subsequently underwent MRI temporal bones prior to cochlear implant device insertion. All implanted patients were subjected to post operative radiography to assess position of implant. Results : Both modalities provided critical information on abnormalities of the otic capsule, pneumatisation of the mastoid, middle ear abnormalities, cochlear ducts patency and vascular abnormalities- thus helping to assess the suitability of the ear for implantation, determine the side to be implanted and to find any associated abnormality which could adversely influence the surgery or post op period. HRCT missed two cases of luminal ossification and MRI was more reliable in detecting early luminal obstruction. Conclusion : Based on our findings, we offer a realistic and practical protocol for imaging in cochlear implants in the Indian setting. HRCT is recommended in all patients for pre implant analysis of the temporal bone morphology due to its reliability and easy availability. MRI is recommended in all cases of post meningitic deafness and in others with doubtful CT findings.