Abstract:

Background: We Explored the strength and weaknesses of Multi-detector computed tomography (MDCT) and Magnetic resonance imaging (MRI) in preoperative evaluation of cochlear implant candidates.

Methods: A retrospective study including 13 adults and 38 pediatric patients who suffered from bilateral profound sensory neural hearing loss (SNHL) and underwent MDCT and MRI examination as a preoperative assessment for cochlear implant procedure. All patients underwent high-resolution spiral MDCT (128-slice) and 1.5 T MRI examination. Notes of history and physical ear examination, audiometry results, and operative data were collected and compared with imaging findings. 

Results: MDCT was superior in demonstration of middle ear disease while MRI was more useful in delineation of the cochlear nerve and cochlear patency and detection of central causes of SNHL . Only 15% of adult patients had a positive clinical concern and showed positive imaging findings. All adult patient that had no clinical concern showed no significant imaging findings. About 36.8% of pediatric patients had a positive clinical concern and showed positive imaging findings. About 33.3% of pediatric patients who had no clinical concern showed positive imaging findings. The surgical plan was changed based on combined imaging findings in 15.4% of adult patients and 39.4% of pediatric patients.

Conclusion: Multi-detector computed tomography and Magnetic resonance imaging are useful in the evaluation of congenital anomalies of inner ear. MRI is superior in  the evaluation of cochlear nerve ,early detection of labyrinthine fibrosis and detection of intrauterine causes of SNHL. MDCT is helpful in evaluation of middle ear pathology and enables detailed evaluation of osseous anatomy. Integrative employment of both modalities in preoperative assessment of cochlear implant candidates is recommended.