الفهرس 
Development of inner earOnly 14 pages are availabe for public view
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Abstract
Sensorineural hearing loss in children may have congenital causes, such as dysplastic malformations of the inner ear and/or the internal auditory canal, or acquired reasons, such as labyrinthitis .The final stage of sensorineural hearing loss can be complete deafness. These patients often benefit from cochlear implant surgery .
Radiologic abnormalities of the inner ear are relatively common in children with SNHL, and their identification directly impacts prognosis and management. Therefore, many authors suggest that all children with SNHL undergo radiologic imaging as part of their evaluation.
MRI and CT are widely used diagnostic examinations in addition to the clinical examination and audiometric analysis. CT of the temporal bone provides excellent depiction of osseous structures, while MRI enables excellent visualization of soft tissue structures .
Several authors described the effectiveness of MRI with thin-section 3D T2-weighted gradient echo or fast spin echo sequences to assess the region of the inner ear.Therefore, many otologists request both CT and MRI as standard procedures in the assessment of patients with sensorineural hearing loss who are potential candidates for cochlear implant surgery.
The visualization of the different changes that affect the region of the inner ear and the internal auditory canal are visible in most cases with CT, but in all cases with thin-section 3D MRI. These facts enhance the important imaging role of MRI in children with sensorineural hearing loss.
Therefore, in addition to CT, 3D MRI, using thin section 3D T2-weighted sequences and 3D T1-weighted sequences, should be performed in pediatric patients scheduled for cochlear implant surgery, especially in cases where the CT exam demonstrates a narrow internal auditory canal or is regarded as entirely normal.
There is no one right answer to the question of which imaging test is best for patients with hearing loss who are candidates for cochlear implantation (CI). Age, underlying pathology and the ability to tolerate radiation and sedation are just a few of the variables that can determine whether magnetic resonance imaging (MRI), computed tomography (CT) or both are chosen in this clinical setting.
It has been estimated that MRI can determine the cause of hearing impairment in approximately 30% of patients with SNHL. However, despite the great advances in imaging technology, there are a number of congenital and acquired abnormalities of the inner ear that do not have any radiologic manifestations. Many of the membranous labyrinthine dysplasias and metabolic, toxic, infectious, or idiopathic causes of SNHL do not demonstrate any abnormality on CT or MRI. Nevertheless, imaging is an indispensable tool for the evaluation of congenital and acquired causes of SNHL. Knowledge of the various pathologies of the inner ear and central auditory pathways can aid in better consultation and management of patients with SNHL.
Each scan did have some shortcomings. In the case of CT, for example, the test failed to consistently detect early obliterative labrynthitis and the presence of the cochlear nerve in the internal auditory canal. The MRI test often missed the presence of enlarged vestibular aqueducts and narrow cochlear nerve canals.
And thus , from our study we conclude that:
“Dual-modality imaging,” using both CT and MRI, made sense for many patients because the dual-scan approach “detects abnormalities related to deafness that would not otherwise be found using either modality alone.”