Pre-, Intra- and Post-Operative Imaging of Cochlear Implants

Abstract

The purpose of this review is to present essential imaging aspects in patients who are candidates for a possible cochlear implant as well as in postsurgical follow-up.?Imaging plays a major role in providing information on preinterventional topography, variations and possible infections. Preoperative imaging using DVT, CT, MRI or CT and MRI together is essential for candidate selection, planning of surgical approach and exclusion of contraindications like the complete absence of the cochlea or cochlear nerve, or infection. Relative contraindications are variations of the cochlea and vestibulum. Intraoperative imaging can be performed by fluoroscopy, mobile radiography or DVT. Postoperative imaging is regularly performed by conventional X-ray, DVT, or CT. In summary, radiological imaging has its essential role in the pre- and post-interventional period for patients who are candidates for cochlear implants. Key Points: ??Intraoperative imaging: radiography, DVT ??Preoperative imaging: DVT, CT, MRI ??Postoperative imaging: X-ray, DVT, CT Citation Format: ??Vogl TJ, Tawfik A, Emam A et?al. Pre-, Intra- and Post-Operative Imaging of Cochlear Implants. Fortschr R?ntgenstr 2015; 187: 980???989

Effectiveness of skull X-RAY to determine cochlear implant insertion depth

“…Lastly, the Stenvers view was not routinely available for our patients and was not assessed. However, this view is commonly used in cochlear implantation studies to assess insertion depth [12, 21, 22]. …”

“…CT is a highly accurate technique physicians currently utilize and can be reconstructed to yield 3D high-resolution data to determine electrode position [12, 14–16]. More commonly, immediate post-operative skull X-RAYs are performed following CI surgery at implant centres.…”

“…At Sunnybrook Health Sciences Centre (SHSC), our patients undergo a routine three-view series of X-RAYs often the night of their surgery, or occasionally the day afterwards. These X-RAYs help confirm appropriate electrode placement within the cochlea including insertion depth, as well as identify kinking, squeeze, and integrity of the electrode [12]. …”

The Forgotten Second Window: A Pictorial Review of Round Window Pathologies

“…The electrode can kink, flip over at its tip, or migrate. 68,69 Postoperative imaging can also demonstrate various degrees of electrode displacement, including within the semicircular canal, internal carotid artery, internal auditory canal, and vestibule. 69,70 Across time, electrodes may also migrate from their initial position (Fig 13).…”

“…68,69 Postoperative imaging can also demonstrate various degrees of electrode displacement, including within the semicircular canal, internal carotid artery, internal auditory canal, and vestibule. 69,70 Across time, electrodes may also migrate from their initial position (Fig 13). Postoperative images should be evaluated in the context of the surgical approach (ie, via the round window or adjacent cochleostomy) and should include an assessment of electrode position, integrity, and change since prior examinations.…”