A 3-year-old developed bilateral profound sensorineural hearing loss after bacterial meningitis. High resolution CT of the temporal bone appears normal, and cochlear implantation is planned. Which investigation will best detect early obliteration of the scala tympani before surgery?
- A Repeat high resolution CT with bone windows
- B MRI of the internal auditory meati with heavily T2 weighted sequences ✓
- C PET CT of the petrous temporal bones
- D Transcranial Doppler of the basilar artery
Correct answer: B. MRI of the internal auditory meati with heavily T2 weighted sequences
Explanation
Post-meningitic deafness can progress to labyrinthitis ossificans, which begins as fibrous tissue filling the scala tympani of the basal turn before any bone forms. Heavily T2 weighted MRI demonstrates loss of the normal fluid signal in the scala tympani at this stage, while CT becomes abnormal only once ossification is established. Identifying obliteration early allows selection of the better hearing ear and planning for a drilled opening or shortened electrode if the basal turn is blocked.
Reference: Cummings Otolaryngology Head and Neck Surgery, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.