Computed tomography versus magnetic resonance imaging in paediatric cochlear implant assessment: a pilot study and our experience at Great Ormond Street Hospital.

Background. To date, there is a lack of consensus regarding the use of both computed tomography and magnetic resonance imaging in the pre-operative assessment of cochlear implant candidates. Methods. Twenty-five patients underwent high-resolution computed tomography and magnetic resonance imaging. 'Control scores' describing the expected visualisation of specific features by computed tomography and magnetic resonance imaging were established. An independent radiological review of all computed tomography and magnetic resonance imaging scan features was then compared to the control scores and the findings recorded. Results. Agreement with control scores occurred in 83 per cent (20 out of 24) of computed tomography scans and 91 per cent (21 out of 23) of magnetic resonance imaging scans. Radiological abnormalities were demonstrated in 16 per cent of brain scans and 18 per cent of temporal bone investigations. Conclusion. Assessment in the paediatric setting constitutes a special situation given the likelihood of congenital temporal bone abnormalities and associated co-morbidities that may be relevant to surgery and prognosis following cochlear implantation. Both computed tomography and magnetic resonance imaging contribute valuable information and remain necessary in paediatric cochlear implant pre-operative assessment.