# Pre-operative High-Resolution CT and MRI Evaluation in Pediatric Cochlear Implant Candidates: Correlation With Surgical Findings and Outcomes

## TL;DR

This study shows that combining CT and MRI scans helps doctors accurately assess and prepare for cochlear implant surgeries in children with hearing loss.

## Contribution

The study demonstrates the predictive value of combined HRCT and MRI in identifying surgical challenges and optimizing outcomes in pediatric cochlear implantation.

## Key findings

- HRCT and MRI reliably identified inner ear malformations and surgical risk factors in pediatric patients.
- Imaging predicted intraoperative perilymphatic gushers in cases with inner ear malformations.
- Combined imaging protocols improved surgical planning and postoperative outcomes.

## Abstract

Purpose

Congenital sensorineural hearing loss (SNHL) is a major childhood disability, and early cochlear implantation offers optimal auditory and language outcomes. High-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) are essential in evaluating candidacy, identifying inner ear malformations (IEMs), assessing cochlear nerve integrity, and predicting surgical challenges. This study evaluates the role of HRCT and MRI in pediatric cochlear implant candidates and correlates imaging findings with intraoperative events and postoperative outcomes.

Methods

This retrospective study included 32 children (<7 years) with congenital SNHL who underwent HRCT and MRI of the temporal bones. HRCT assessed mastoid pneumatization, middle ear status, vascular variants, facial recess anatomy, and cochlear morphology. MRI evaluated the membranous labyrinth, cochleovestibular nerve, internal auditory canal (IAC), and brain. Exclusion criteria included lack of consent, age >7 years, metallic implants, pacemakers, or prior cochlear implantation. Surgical records were retrospectively reviewed to assess operative complexity, including duration of surgery, intraoperative challenges, and complications encountered.

Results

Among 32 patients (mean age 2.9 years), mastoid aeration was normal in 81.25%, and the middle ear cavity was aerated in 90.63%. Sigmoid sinus variants, high-riding jugular bulbs (18.75%), and low-lying dural plates (34.38%) were common. Vestibular aqueduct anomalies were identified in 18.75%. The cochlear aperture was normal in 74.88%, widened in 12.5%, and stenosed in 6.25%. Inner ear malformations were present in 15.63%, including large vestibular aqueduct syndrome (LVAS), incomplete partitions, and cochlear hypoplasia, with cochlear nerve aplasia in two cases. Nineteen patients underwent cochlear implantation; all IEM cases experienced intraoperative perilymphatic gushers, consistent with imaging predictions. All surgeries used the transmastoid facial recess approach with an extended round window technique. Postoperative recovery was uneventful in all cases.

Conclusions

HRCT and MRI together provide a comprehensive assessment of pediatric cochlear implant candidates, enabling precise identification of IEMs, cochlear nerve anomalies, and surgical risk factors. Imaging reliably predicts intraoperative challenges such as gushers and aids in tailoring surgical approaches. A combined CT-MRI protocol is indispensable for optimizing safety, minimizing complications, and enhancing postoperative outcomes in pediatric cochlear implantation.