The Study On The Diagnosis And Application Of Virtual Endoscopy In Lesion Of Ossicular Chain In The Middle Ear

Objective:To explore the diadynamic criteria of virtual endoscopy(VE) in the normal middle ear.To research the diagnoxtic value and clinical significance of VE in the middle ear diseases which include inflammation,trauma and deformity.Methods:A diadynamic criterion of normal ossicular chain was established by observing the VE of 30 normal middle ears.96 ears with chronic otitis media which include simple type of 14 ears,osteitis type of 44 ears and cholesteatoma type of 38 ears,24 ears with congenital malfomations of the middle or external-minddle ear,10 ears with discontinuance of ossicular chain in trauma were chosen,all of which were performed by high resolution CT scan and get the VE before surgery.The diagnostic effect of VE in microsurgery of the ear was explored by Contrasting the ossicular chain in operation and the VE of ossicular chain before sugery.Results:VE is 100%valuable for the evaluation of normal middle ear structures which include head of malleus,handle of malleus,body of incus,short/long process of incus,supra structure of stapes,incudomalleolar joint,incudostapedial joint,facial recess,round window niche,pyramidal eminence,sinus tympani,tuber cochleae,and tympanic opening of auditory tube,while there is a little difficult to classify the base of stapes.The accuracy of VE in congenital malfomations of the middle or external-minddle ear is 98.33%,and the accuracy of VE in discontinuance of ossicular chain in trauma is 100%.But the accuracy of VE in osteitis type and cholesteatoma type of chronic otitis media is 95.45%and 81.58%.A combination of HRCT and VE are needed to diagnose the ossicular chain with cholesteatoma or granulation.Conclusion:1.VE can accurate display the three-dimentional special structure of normal middle ear.It is a high diagnostic value to simple type of chronic otitis media, congenital malfomations of the middle or external-minddle ear and discontinuance of ossicular chain in trauma. 2.VE can display the ossicular chain in cholesteatoma type and osteitis type of chronic otitis media,but combination of HRCT and VE are need to diagnose the ossicular chain with cholesteatoma or granulation.3.VE provides reliable imaging documentation for diagnosis and better personal design of the surgical approach before surgery.