Preoperative imaging protocol for cochlear implant candidates

OBJECTIVE: To formulate and test a CT imaging protocol for preoperative scanning of the temporal bone in cochlear implant candidates. MATERIAL AND METHODS: A human head was scanned in three CT planes: axial, axiopetrosal and semilongitudinal. Multiplanar reformats (MPRs), based on axial slices, were created and compared with the corresponding images obtained by direct scanning in the respective planes. All scans were analyzed on a viewing workstation. RESULTS: The axial plane image allowed for an overview of the temporal bone. The width of the facial recess and the cochlear nerve canal could be studied on combined axial and axiopetrosal images. Cochlear patency could be evaluated using combined axial and semilongitudinal images. Axiopetrosal and semilongitudinal MPRs were able to replace the images obtained by direct scanning in the respective planes. CONCLUSION: The combination of the axial CT plane image and MPRs was found to be sufficient for preoperative analysis of the temporal bone morphology.