Imaging Findings of Labyrinth Involved by Otitis Media

Objective:To study the High resolution CT(HRCT)and MRI findings of labyrinth involved by otitis media diagnosd by comprehensive clinical features.Methods:HRCT and MRI findings in twenty-four cases(twenty-four ears)with labyrinth involved by otitis media were retrospectively analyzed.Results:Of the 8 ears had only bony labyrinth erosion which proved by surgery,HRCT in seven ears showed bony destruction and the mid ear lesion was in close contact to the labyrinth cavity.Of the 14 ears had labyrinth cavity lymph fluid involvement,9 ears showed bony destruction and 5 ears showed intact bony labyrinth by HRCT.On MRI,8 ears had lymph fluid within lacrimal cavity showing increased signal intensity on T1WI and no change of signal intensity on T2WI;7 ears showed marked enhancement after contrast administration and 1 ear showed mild enhancement.5 ears with lymph fluid showed increase signal intensity on T1WI and decreased signal intensity on T2WI;4 ears had significant enhancement and 1 ear had mild enhancement.1 ear with lymph fluid showed no signal intensity change on both T1 and T2WI,yet obvious enhancement after contrast administration.One ear had labyrinth hyperostosis and sclerosis,cochlea hyperostosis,sclerosis and stricture of labyrinth cavity were assessed on HRCT,narrowing of cochlea cavity was assessed on MRI.Extensive destruction of bony labyrinth was showed in 1 ear,the lesion located within the bony labyrinth posterior to the cochlea,extensive soft tissue density was assessed on HRCT,with surrounding bony destruction and intra-lesion irregular seqestrum;mixed intensities both on T1WI and T2WI within the lesion accompanied with uneven enhancement were revealed on MRI.Conclusion:HRCT and MRI can accurately diagnose the extent and location of labyrinth involved by otitis media,which can provide important information in treatment planning.