Role of high resolution CT and radiography in postoperative evaluation of cochlear implantation

ObjectiveTo assess the role of HRCT and Radiography in postoperative evaluation of cochlear implants.Patients and methodsRadiography; including Stenver's and modified Chause III positions, as well as HRCT were carried out in 12 patients with cochlear implants. HRCT images were obtained utilizing 0.625 mm slice thickness followed by reconstruction using 0.3-mm reconstruction increment and high-resolution algorithm.ResultsOn HRCT, complete insertion of electrode array was noted in one patient, incomplete insertion in two and partial insertion in nine patients. The position of the electrode array as compared to CT and radiography revealed agreement in 11 patients; and disagreement in one. The radiologic position of the electrode array was compared to intra-operative electrophysiological testing and surgical data. In three patients, there was agreement. In one patient, contacts 11 and 12 were nonfunctioning with good impedance and were extra-cochlear. One patient had nonfunctioning contact 12 with high impedance and absent stapedial reflex and was extra-cochlear. In one patient, contacts 11 and 12 showed high impedance and were extracochlear. In nine patients, intra-operative electrophysiological testings were satisfactory with three having high impedance of last contact. Facial twitches were encountered in two patients.ConclusionTechnological advances will expand the applications of HRCT in cochlear implant recipients.