BACKGROUND: The aim of this study was to evaluate the feasibility of co-registeringpreoperative MRI and postoperative CT and to assess the position of the electrode within the cochlea.MATERIAL/METHODS: In a series of 14 patients, high-resolution MRI datasets of the cochlea obtained beforeimplantation and multirow CT datasets obtained after implantation were co-registered using a stereoscopicdisplay and volume-rendering platform (Dextroscope, Volume Interactions/Bracco, Singapore). Image co-registrationwas performed with a semi-automatic method (multipoint plus freehand fusion). RESULTS: In 2 patientsthe electrode was correctly inserted in the middle turn of the cochlea and the assigned rank was 4 (correspondingto the initial tract of the middle turn). In 8 patients the rank was 3, meaning that the electrode tipreached the upper portion of the basal turn. In 4 patients the rank was 2, meaning that the electrodetip reached the middle portion of the basal turn; in two of these patients, electrode kinking was observed.CONCLUSIONS: Co-registration of preoperative MRI and postoperative CT is feasible and represents a uniquemethod to assess electrode position within the membranous labyrinth.

Keywords: Adolescent, Cochlea - radiography, Cochlear Implantation, Magnetic Resonance Imaging, Postoperative Period, Tomography, X-Ray Computed