Cochlear implant failure: imaging evaluation of the electrode course.

Cochlear implant (CI) is an electronic device used to rehabilitate patients with sensorineural hearing loss. The intent of this review is to demonstrate the normal position of the electrode on computed tomography (CT) and contrast this with various examples of the electrode malpositioning. Post-implantation CT is performed to localize the cause of implant failure in patients in which radiographs suggest an anomalous course of the electrode. A common cause of device failure is extrusion or malpositioning of the electrode. It is important for the radiologists to recognize this important aspect of device failure. Post-implant CT can help identify patients with malpositioned electrode in whom another attempt can be made by correctly re-implanting the electrode.