Temporal Bone CT Findings of Tuberculous Otitis Media: Comparison with Chronic Otitis Media

ABSTRACT

PURPOSE: To compare the differential findings of tuberculous otitis media(TOM) with those of chronic suppurative otitis media with or without cholesteatoma, as seen on high resolution temporal bone CT. MATERIALS AND METHODS: We retrospectively reviewed 14 cases of TOM, 30 cases of chronic suppurative otitis media(CSOM), and 30cases of chronic otitis media with cholesteatoma(Chole). All had been pathologically confirmed. We evaluated thepreservation of mastoid cells without sclerotic change, the location and extension of soft tissue to the externalauditary canal, the erosion of ossicles, the tegmen tympani, scutum, bony labyr inth, facial nerve canal andsigmoid sinus, and the presence of intracranial co mplications. RESULTS: Soft tissue in the mastoid antrum wasseen in all cases of TOM(100%), 29 cases of CSOM(96.7%), and 26 cases of Chole(86.7%). In contrast, the softtissue in the entire middle ear cavity was noted in 13 cases of TOM(92.8%), 7 cases of CSOM(23.3%), and 12 casesof Chole(40%). Soft tissue extended to the superior aspect of the external auditory canal in 4 cases of TOM(28.6%) and 5 cases of Chole (16.7%). Mastoid air cells were seen in 9 cases of TOM (64.3%), 4 cases of CSOM(13.3%), and 3 cases of Chole(10%). Ossicular erosion was noted in 6 cases of TOM (42.9%), 12 cases of CSOM (40%),and 26 cases of Chole(86.7%), while in one case of TOM (7.1%), 5 cases of CSOM (16.7%), and 15 cases of Chole(50%)there was erosion of the scutum. In one case of TOM, follow-up CT study after 9 months of antituberculousmedication without surgery revealed complete clearing of previously noted soft tissue in the middle ear cavity. CONCLUSION: Specific CT findings of TOM were not seen, but if there were findings of soft tissue in the entiremiddle ear cavity, soft tissue extension to the external auditory canal, preservation of mastoid air cells withoutsclerotic change, and intact scutum, TOM may be differentiated from other chronic otitis media.