Application Of MRI In Observing Inner Ear Fluid To Preoperative For Cochlear Implantation

Objective MRI is a routine examination before surgery for severe and very severe deafpatients preoperative，which can objectively and accurately understand the anatomicalstatus associated with surgery, the conventional CT only reflected Cochlea ossification,But it could be well Manifested on MRI such as cochlea fibrosis， inner earmalformation, cochlear nerve and intracranial lesions. MRI play a reference role onpostoperative efficacy assessments. This article analyzed the results of examinationof200cases of cochlear implant recipients to explore the value of MRI inner ear waterimaging in cochlear implantation.Methods Collected the imaging data of513cases successful cochlea implantationduring February2011to December2012,including the head and the internal auditorychannel MRI and temporal bone CT. all patients completed by a single physician,excluded90cases of national projects. Collected the images and analyzed the results ofCT and MRI of200patients which diagnosed by the same radiologist.Results1.200cases (400ears) patients,164patients with bilateral CT and MRI werenormal, can display double side, vestibulocochlear nerve and inner ear membranouslabyrinth structure MRI3D reconstruction images can clearly show the semicircularcanals of the three groups, showed a "C" shape, perpendicular to each other, thecochlear duct spiral rotated2laps,the bell-like structure in the inside of the cochlearduct is the internal auditory canal, which filled with cerebrospinal fluid showed highsignal. The facial nerve and vestibular nerve could be clearly displayed. 2.14patients (28ears)with expanding vestibular aqueduct could be foundAbnormalities in CT and MRI;13cases (26ears) in patients with abnormalities of theinner ear：13cases were found on MRI, while10cases were found on CT,3caseswere missed;4cases (4ears) were internal auditory canal stenosis diagnosed byMRI, only two cases were found on CT；3cases (3ears) were found cochlea fibrosison MRI, but no abnormalities on CT；one case(an ear) of chronic otitis media, and1case(2ears) of the facial nerve exposed were found on CT. The rate of correctdiagnosis of the abnormal cases (68ears) found in the CT or MRI,77.8%(53/68) wasfound on CT and the MRI was94.1%(64/68).MRI and CT findings were seen as sameas the cochlea implantation.3.15cases of cerebral white matter and a cerebral palsy associated with inner earmalformation were found on MRI.Conclusion Imaging evaluation before cochlea implantation, MRI inner ear waterimaging and cochlea3D reconstruction techniques have unique advantages and canprovide reliable anatomical information of the inner ear membranous labyrinth and theinternal auditory canal nerve. It also play an important role in the diagnosis of thecochlea fibrosis, the abnormal and immature development of cochlear nerve．CranialMRI showed intracranial lesions,assessed the postoperative rehabilitation effects ofthe patients who were white matter and cerebral palsy．Meanwhile,It’s important forthe choosing of cochlea implant cases, the selection of left and right ear and of implantbody’s electrode models. Therefor they are the indispensable means of checking beforecochlea implantation.