“A COMPARATIVE STUDY OF MRI AND HRCT OF SENSORINEURAL HEARING LOSS”

Abstract

Background: In 2012, the World Health Organization (WHO) estimated that 360 million people, that is 5.3% of the world's population had hearing loss. In India, 63 million people (6.3%) have a signicant hearing loss. High-resolution computed tomography (HRCT) of the temporal bone and magnetic resonance imaging (MRI) of the inner ear have been used in this group of patients with some advantages and disadvantages of each modality. To Aim: compare both imaging modality in the evaluation of sensorineural hearing loss and to create a systemic approach for cochlear implant candidacy. This observational study was conducted in the Department of Radiodiagnosis Materials and methods: comprising of 80 ears of 40 patients who having congenital moderate to profound SNHL and were potential candidate for cochlear implant surgery. All patients underwent combined HRCT of temporal bone and MRI inner ear including brain. Results: The mean age of the patients was 3.30 ± 1.49 years with male predominance (57.5%). HRCT found abnormality in 19 ears while MRI picked up abnormality in 22 ears. The number of ears with cochlear (10), vestibular (8) and semi-circular canal (8) abnormalities were similar by both imaging modalities. However, MR additionally detected abnormalities of endolymphatic duct system (12) as compared to vestibular aqueduct (10) on HRCT. Narrow internal auditory canal was found in 5 ears detected by both imaging modalities and all were associated with abnormal cochlear nerve. However, 2 additional cochlear nerve abnormalities associated with normal IAC. We found MRI slightly superior in detection of cause Conclusion: of SNHL. MRI better depicts the uid-lled structures of the inner ear and cochlear nerve, retro-cochlear and cerebral pathology that leads to determination and feasibility of candidacy for cochlear implantation. HRCT is mandatory to rule out any bony anatomical variation and facial nerve course to determine side of implant and minimize intraoperative complication. Therefore, we advocate use of both MRI and HRCT in cochlear implant candidates.