Impact of MSCT in pre-operative assessment of temporal bone in pre lingual and post lingual SNHL prior to cochlear implantation

Abstract

Abstract:

         Aim: Multi-slice CT (MSCT) is considered a crucial diagnostic tool in detection of various etiologies of sensorineural hearing loss (SNHL) which demand different therapeutic methods of which cochlear implantation is considered the surgical procedure of choice in management of profound SNHL. MSCT scan of the petrous bone plays an important role in the preoperative assessment and selection of cases prior to cochlear implantation.

       Methods: This study had a total number of 30 patients referred from the E.N.T department to the department of radiodiagnosis. MSCT was done for evaluation of the cochlear condition before cochlear implantation surgery. MSCT was used to reveal the different inner ear anatomical variants and to orient and modulate the surgical techniques. It was also used to figure out causes of SNHL in pre-lingual (patients who never speak before) and post-lingual (after speech acquisition) patients.

        Results: Only 25 out of 30 patients were good candidates for cochlear implantation surgery according to radiological data, the remaining five cases were not submitted to surgery because they had contraindications, one case diagnosed as Michele anomaly (which is an absolute contraindication), one case diagnosed as Labyrinthitis ossificans (which may affect the insertion of the cochlear array), One case diagnosed as bilateral longitudinal fractures (this case has been postponed for fear of cochlear nerve affection) & Two cases were diagnosed as normal studies on imaging and assumed clinically as post meningitic labyrinthitis  and they are on waiting list due to correlation of their relatively larger age and availability of cochlear implant devices

         Conclusions: MSCT is considered the modality of choice in the assessment of patients with SNHL preoperatively. 

         Keywords: CT /pre-operative /cochlear implantation/ temporal bone.