Abstract
Purpose
Evaluation of a new postprocessing method for postoperative control of cochlear implants (CI) based on a single flat detector computed tomography (FD-CT) run and volume rendering of 3D models of the inner ear.
Methods
The FD-CT datasets of CIs were selected and postprocessed to generate both standard multiplanar reconstructions (MPR) and merged volume-rendered 3D datasets (MRD) of the CIs. The MRDs consisted of two different reconstructions (bone/implant) that are automatically layered to avoid manual coregistration inaccuracy. Corresponding datasets were evaluated in consensus reading in terms of qualitative (integrity, position, configuration) and quantitative (insertion depth angle) CI parameters.
Results
In total 20 FD-CTs with 20 CIs were successfully postprocessed. Qualitative evaluation of MPR and MRD demonstrated complete congruency (integrity: narray integrity = 20; position: nscala tympani = 13, nscalar translocation = 7; configuration: nharmonic spiralization = 16, ntip fold over = 3, nlooped implant = 1). Adverse intracochlear implant spiralization was identified in all 10 cases with MRD and MPR. Measurement of the insertion depth angle in MRD was equivalent to that in MPR (r = 0.99; P = <0.0001).
Conclusion
The use of MRD is a helpful method for precise postoperative CI assessment and provides easy detection of incorrect intracochlear spiralization.
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References
NIDCD. Cochlear Implants. 2016. https://www.nidcd.nih.gov/health/cochlear-implants. Accessed 17 Feb 2019.
Lin K, Marrinan MS, Waltzman SB, Roland JT Jr. Multichannel cochlear implantation in the scala vestibuli. Otol Neurotol. 2006;27:634–8.
Kiefer J, Weber A, Pfennigdorff T, von Ilberg C. Scala vestibuli insertion in cochlear implantation: a valuable alternative for cases with obstructed scala tympani. ORL J Otorhinolaryngol Relat Spec. 2000;62:251–6.
O’Connell BP, Hunter JB, Wanna GB. The importance of electrode location in cochlear implantation. Laryngoscope Investig Otolaryngol. 2016;1:169–74.
Lee J, Nadol JB Jr, Eddington DK. Depth of electrode insertion and postoperative performance in humans with cochlear implants: a histopathologic study. Audiol Neurootol. 2010;15:323–31.
Aschendorff A. Imaging in cochlear implant patients. GMS current topics in otorhinolaryngology Head Neck Surg. 2012;10:Doc7.
Dörfler A, Struffert T, Engelhorn T, Richter G. Rotational flat-panel computed tomography in diagnostic and interventional neuroradiology. Rofo. 2008;180:891–8.
Struffert T, Hertel V, Kyriakou Y, Krause J, Engelhorn T, Schick B, Iro H, Hornung J, Doerfler A. Imaging of cochlear implant electrode array with flat-detector CT and conventional multislice CT: comparison of image quality and radiation dose. Acta Otolaryngol. 2010;130:443–52.
Arweiler-Harbeck D, Mönninghoff C, Greve J, Hoffmann T, Göricke S, Arnolds J, Theysohn N, Gollner U, Lang S, Forsting M, Schlamann M. Imaging of electrode position after cochlear implantation with flat panel CT. ISRN Otolaryngol. 2012;2012:728205.
Struffert T, Hauer M, Banckwitz R, Köhler C, Royalty K, Doerfler A. Effective dose to patient measurements in flat-detector and multislice computed tomography: a comparison of applications in neuroradiology. Eur Radiol. 2014;24:1257–65.
Teymouri J, Hullar TE, Holden TA, Chole RA. Verification of computed tomographic estimates of cochlear implant array position. Otol Neurotol. 2011;32:980–6.
Postnov A, Zarowski A, De Clerck N, Vanpoucke F, Offeciers FE, Van Dyck D, Peeters S. High resolution micro-CT scanning as an innovative tool for evaluation of the surgical positioning of cochlear implant electrodes. Acta Otolaryngol. 2006;126:467–74.
Verbist BM, Frijns JH, Geleijns J, van Buchem MA. Multisection CT as a valuable tool in the postoperative assessment of cochlear implant patients. AJNR Am J Neuroradiol. 2005;26:424–9.
Kong WJ, Cheng HM, Ma H, Wang YJ, Han P. Evaluation of the implanted cochlear implant electrode by CT scanning with three-dimensional reconstruction. Acta Otolaryngol. 2012;132:116–22.
Dees G, van Hoof M, Stokroos R. A proposed method for accurate 3D analysis of cochlear implant migration using fusion of cone beam CT. Front Surg. 2016;3:2.
Dietz A, Gazibegovic D, Tervaniemi J, Vartiainen VM, Löppönen H. Insertion characteristics and placement of the Mid-Scala electrode array in human temporal bones using detailed cone beam computed tomography. Eur Arch Otorhinolaryngol. 2016;273:4135–43.
Dietz A, Iso-Mustajärvi M, Sipari S, Tervaniemi J, Gazibegovic D. Evaluation of a new slim lateral wall electrode for cochlear implantation: an imaging study in human temporal bones. Eur Arch Otorhinolaryngol. 2018;275:1723–9.
Hinkmann FM, Voit HL, Anders K, Baum U, Seidensticker P, Bautz WA, Lell MM. Ultra-fast carotid CT-angiography: low versus standard volume contrast material protocol for a 128-slice CT-system. Investigative Radiology. 2009;44:257–64.
Zeitler DM, Wang KH, Prasad RS, Wang EY, Roland JT. Flat-panel computed tomography versus multislice computed tomography to evaluate cochlear implant positioning. Cochlear Implants International. 2011;12:216–22.
Kennedy TA, Connell N, Szczykutowicz T, Schafer S, Royalty K, Nace S, Gartrell B, Gubbels S. Flat-panel CT for cochlear implant electrode imaging: comparison to multi-detector CT. Otol Neurotol. 2016;37:1646–53.
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F. Eisenhut, S. Lang, L. Taha, A. Doerfler, H. Iro and J. Hornung declare that they have no competing interests.
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Eisenhut, F., Lang, S., Taha, L. et al. Merged Volume Rendered Flat-panel Computed Tomography for Postoperative Cochlear Implant Assessment. Clin Neuroradiol 30, 721–728 (2020). https://doi.org/10.1007/s00062-019-00832-x
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DOI: https://doi.org/10.1007/s00062-019-00832-x