Radiological study of temporal bone in children with profound deafness before cochlear implant: CT vs magnetic resonance imaging

Objective To evaluate the clinical application of magnetic resonance imaging (MRI) and CT in children with profound deafness before cochlear implant and their impact on surgical decision. Methods The pre-operative CT and MRI data from 71 children with bilateral profound deafness planned for cochlear implant were studied. Results 12 patients showed enlarged vestibular aqueduct (16.9%); 14 patients had Mondini malformation (19.7%); 3 patients demonstrated enlarged internal auditory meatus (4.2%); and 2 patients were suspected to have fistulae (2.8%) on both CT and MRI examinations. In comparison between MRI and CT, unilateral cochlear fibrosis was detected in 5 patients(7%) by MRI, but none by CT scans. Bilateral dehiscent facial nerve was detected in 1 patient(1.4%) by CT scan, while MRI was normal. Conclusion CT and MRI are essential for the pre-operative planning of cochlear implant, especially in patients with enlarged vestibular aqueduct, Mondini malformation, enlarged internal auditory meatus and suspected fistulae. These two imaging modalities are complementary to each other in cases with cochlear fibrosis and facial nerve dehiscence.