Imaging the Postoperative Neck

Imaging Review of the Temporal Bone: Part II. Traumatic, Postoperative, and Noninflammatory Nonneoplastic Conditions

“…Tympanostomy (ventilation) tubes are commonly inserted into the tympanic membrane via an incision in the tym panic membrane (myringotomy) for treating chronic or recurrent otitis me dia recalcitrant to medical management (33,34). Tubes are available in different shapes, sizes, and materials, most com monly Teflon or silicone, which have softtissue attenuation on CT images (Fig 10).…”

“…The different types of mastoidectomy essentially consist of resecting variable portions of the mastoid air cells and adjacent structures, which may be per formed for treatment of mastoiditis, cholesteatoma resection, cochlear im plantation, or endolymphatic surgery, among other indications (33,36). Canal wallup mastoidectomy involves exen teration of the mastoid air cells with preservation of the posterior wall of the external auditory canal, creating a mastoid bowl or cavity (Fig 11).…”

“…A variety of techniques can be per formed for ossicular reconstruction (33,36,40). Stapes prostheses are used in patients with conductive hearing loss due to otosclerosis or congenital anom alies and typically consist of two compo nents-a loop and a piston.…”

“…The basic components of a co chlear implant include a microphone, speech processor, and transmitter coil externally, and a receiverstimulator internally, which leads to a cable end ing in an electrode array within the co chlea. The electrode array usually con tains eight to 24 stimulators that are tuned to particular acoustic frequencies (33,36,42). Typical surgery for cochlear implantation consists of performing canalwallup mastoidectomy and intro ducing the electrode through the mid dle ear cavity through the facial recess and into a widened round window niche.…”

“…Complications related to cochlear implantation occur in less than 1% of cases and include device malposi tion or migration, breakage, facial nerve canal dehiscence and stimulation or injury, pneumolabyrinth, and bone ero sion, which are best evaluated with CT, and abscess, meningitis, and labyrinthi tis, which are best evaluated with MR imaging (33,42). Ultimately, highspa tialresolution temporal bone CT and MR imaging are useful for proper pre operative planning and avoiding compli cations and failure of cochlear implan tation.…”