The Assessed Evaluation Of Temporal Bone High Resolution Computed Tomography And Inner Ear Magnetic Resonance Imaging Before Cochlear Implantation

Objective: Explore the assessed evaluation of imaging examination (temporalbone high resolution computed tomography and inner ear magnetic resonance imaging)in cochlear implantation,and explore to establish a comprehensive and normativeImaging inspection system.Methods:Using the double source CT scanner of SIEMENS.The scope ofTemporal bone cross-sectional high-resolution computed tomography (CT) is fromgradenigo to the tip of mastoid,which was including the whole structure of middle earand inner ear.Using SIEMENS Verio3.0T superconducting magnetic resonance imaging (mri)scanners and the standard headt circle.The patients were in the supine position,whoseheads entered first. Brain scan and Inner ear routine scan used rapid acquisition withrelaxation enhancement sequence. Inner ear water imaging used the sequence ofT2-SPACE.To process magnetic resonance images: send original data to the workstationof Syngo MultiModality Workplace after the completion of the scaning. Maximumintensity projection(MIP) and multiple planar reconstruction (MPR) are used to rebuildand deal with the original images. Through Maximum intensity projection, Workplaceprovides the cutting tools in order to minus the redundant tissue around and get theinner ear water imaging image. After multi-angle and multi-azimuth observation, theinner ear structure were showed completely.using the reconstruction method of multipleplanar reconstruction,which could get the oblique sagittal images perpendicularly tointernal auditory canal,and the morphology and structure of four nervous (facial nerve,cochlear nerve and vestibular nerve) could be showed and assessed. Set up evaluationand diagnosis groups, which included two radiologists and one otolaryngologist. Theyassessed and diagnosed the absolute contraindications, relative contraindications andsome other lesions which were related to cochlear implanation, and recorded the data.At last, we made statistical analysis and used the method of Kappa identity test analysis tocheck the consistency of the two inspection methods(P<0.05).If the Kappa value wasmore than0.75or equal to0.75, the consistency of the two inspection methods wasgood. If the Kappa value was between0.4to0.75, the consistency of the two inspectionmethods was acceptable. If the Kappa value was less than0.4, the consistency of thetwo inspection methods was bad.Results:50cases of patients were successfully completed temporal bone highresolution computed tomography and inner ear magnetic resonance imaging, and theinner ear structures were displayed clearly in all the cases. In50cases of patients，theinspection results of temporal bone HRCT and inner ear MRI were mentioned belowrespectively: Michel malformation were5cases and1case, cochlear aplasia were4cases and1case, lack of cochlear nerve in internal auditory canal were1case and4cases, poor pneumatization of mastoids were5cases and1case, high jugular bulb were16cases and3cases, leukodystrophy were2cases which were founded in MRI, theconsistency of two inspection results were bad. Acute purulent otitis media andmastoiditis were4cases and3cases, large vestibule aqueduct syndrome were21casesand17cases, bone defect of internal auditory canal was1case and1case. cochlearhypoplasia were3cases and3cases, the consistency of two inspection results weregood. Neurofibromatosis type2(NF2) were2cases and5cases, common cavity were4cases and2cases, cystic cochlea-vestibule deformity (IP-Ⅰ) were3cases and1cases,mondini malformation were6cases and3cases, occlusive ossifying labyrinthitis were1case and3cases, fronting or deep sigmoid sinus29cases and19cases, the consistencyof two inspection results were acceptable.Conclusion:1. Temporal bone high resolution computed tomography(HRCT) is able to showthe anatomical morphology of inner ear clearly and objectively,especially in showingbony structure of temporal bone, which were related to cochlear implanation.2.Magnetic resonance imaging (MRI) could be an effective tool to help identify themembranous labyrinth of cochlea, and could also make an objective and accurateevaluation of the auditory nerve, which were related to cochlear implanation.3. Temporal bone high resolution computed tomography(HRCT) and inner earmagnetic resonance imaging (MRI) both have high detection rates of some diseaseswhich were related to cochlear implanation, such as acute purulent otitis media and mastoiditis, large vestibule aqueduct syndrome, bone defect of internal auditory canal,cochlear hypoplasia and so on.4.Combining temporal bone high resolution computed tomography(HRCT) withinner ear magnetic resonance imaging (MRI) could make a comprehensive evaluation ofthe absolute contraindications, relative contraindications and some other lesions whichwere related to cochlear implanation,which have a high value before cochlearimplantation.