Paediatric cochlear implantation: how reliable is computed tomography in assessing cochlear patency?

This study investigates the accuracy of pre-operative high resolution computed tomographic (CT) scans in predicting the patency of the cochlea in children undergoing cochlear implantation. The first 26 children on the Nottingham Paediatric Cochlear Implant Programme were reviewed. CT scans were performed utilizing 1 mm contiguous sections and these were then assessed by a neuroradiologist. In patients who had normal inner ears on CT a high degree of accuracy in predicting a patent cochlear was achieved (87%). However, in 15% of cases the degree of ossification was significantly under-estimated causing major difficulties at the time of surgery. Although high resolution CT offers great clarity and fine detail, it has its limitations. Further information may be provided by magnetic resonance imaging.