Imaging of Electrode Position after Cochlear Implantation with Flat Panel CT

Background. Postoperative imaging after cochlear implantation is usually performed by conventional cochlear view (X-ray) or by multislice computed tomography (MSCT). MSCT after cochlear implantation often provides multiple metal artefacts; thus, a more detailed view of the implant considering the given anatomy is desirable. A quite new method is flat panel volume computed tomography. The aim of the study was to evaluate the method’s clinical use. Material and Methods. After cochlear implantation with different implant types, flat panel CT scan (Philips Allura) was performed in 31 adult patients. Anatomical details, positioning, and resolution of the different electrode types (MedEL, Advanced Bionics, and Cochlear) were evaluated interdisciplinary (ENT/Neuroradiology). Results. In all 31 patients cochlear implant electrode array and topographical position could be distinguished exactly. Spatial resolution and the high degree of accuracy were superior to reported results of MSCT. Differentiation of cochlear scalae by identification of the osseous spiral lamina was possible in some cases. Scanning artefacts were low. Conclusion. Flat panel CT scan allows exact imaging independent of implant type. This is mandatory for detailed information on cochlear electrode position. It enables us to perform optimal auditory nerve stimulation and allows feed back on surgical quality concerning the method of electrode insertion.

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Flat-Panel Volume Computed Tomography for Cochlear Implant Electrode Array Examination in Isolated Temporal Bone Specimens

Otology & Neurotology ◽

10.1097/00129492-200606000-00010 ◽

2006 ◽

Vol 27 (4) ◽

pp. 491-498 ◽

Cited By ~ 21

Author(s):

Soenke H. Bartling ◽

Rajiv Gupta ◽

Attila Torkos ◽

Christian Dullin ◽

Grabbe Eckhardt ◽

...

Keyword(s):

Computed Tomography ◽

Cochlear Implant ◽

Temporal Bone ◽

Electrode Array ◽

Flat Panel ◽

Volume Computed Tomography

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Implementation of secondary reconstructions of flat-panel volume computed tomography (fpVCT) and otological planning software for anatomically based cochlear implantation

European Archives of Oto-Rhino-Laryngology ◽

10.1007/s00405-021-06924-0 ◽

2021 ◽

Author(s):

Franz-Tassilo Müller-Graff ◽

Lukas Ilgen ◽

Philipp Schendzielorz ◽

Johannes Voelker ◽

Johannes Taeger ◽

...

Keyword(s):

Computed Tomography ◽

Cochlear Implantation ◽

Surgical Planning ◽

Imaging Data ◽

Flat Panel ◽

Implanted Electrodes ◽

Volume Computed Tomography ◽

Planning Software ◽

Postoperative Setting

Abstract Purpose For further improvements in cochlear implantation, the measurement of the cochlear duct length (CDL) and the determination of the electrode contact position (ECP) are increasingly in the focus of clinical research. Usually, these items were investigated by multislice computed tomography (MSCT). The determination of ECP was only possible by research programs so far. Flat-panel volume computed tomography (fpVCT) and its secondary reconstructions (fpVCTSECO) allow for high spatial resolution for the visualization of the temporal bone structures. Using a newly developed surgical planning software that enables the evaluation of CDL and the determination of postoperative ECP, this study aimed to investigate the combination of fpVCT and otological planning software to improve the implementation of an anatomically based cochlear implantation. Methods Cochlear measurements were performed utilizing surgical planning software in imaging data (MSCT, fpVCT and fpVCTSECO) of patients with and without implanted electrodes. Results Measurement of the CDL by the use of an otological planning software was highly reliable using fpVCTSECO with a lower variance between the respective measurements compared to MSCT. The determination of the inter-electrode-distance (IED) between the ECP was improved in fpVCTSECO compared to MSCT. Conclusion The combination of fpVCTSECO and otological planning software permits a simplified and more reliable analysis of the cochlea in the pre- and postoperative setting. The combination of both systems will enable further progress in the development of an anatomically based cochlear implantation.

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Continuous Facial Nerve Stimulation During Cochlear Implantation – An Electrophysiological Technique to Control the Intracochlear Electrode Contact Position

10.21203/rs.3.rs-829037/v1 ◽

2021 ◽

Author(s):

David Herrmann ◽

Franz-Tassilo Müller-Graff ◽

Stefan Kaulitz ◽

Mario Cebulla ◽

Anja Kurz ◽

...

Keyword(s):

Facial Nerve ◽

Cochlear Implantation ◽

Electrode Position ◽

Electric Pulses ◽

Volume Computed Tomography ◽

Basal Half ◽

Apical Half ◽

Electrode Insertion ◽

Electrophysiological Technique ◽

Contact Position

Abstract Purpose: This proof of concept describes the use of evoked electromyographic (EMG) activation of the facial nerve for intraoperative monitoring of the electrode insertion during cochlear implantation (CI).Methods: Intraoperative EMG measurements from the facial nerve were conducted in nine patients undergoing CI implantation. Electric pulses were emitted from contacts on the CI array during and immediately after electrode insertion. For control, the results of EMG measurements were compared to postoperative flat panel volume computed tomography scans with secondary reconstruction (fpVCTSECO).Results: During insertion, the EMG response evoked by the electrical stimulation from the CI was growing with the stimulating contact approaching the facial nerve and declined with increasing distance. After full insertion, contacts on the apical half of the CI array stimulated higher EMG responses compared with those on the basal half. Comparison with postoperative imaging demonstrated that electrode contacts stimulating high EMG responses had the shortest distances to the facial nerve. Conclusion: It could be demonstrated that electrically evoked EMG activation of the facial nerve can be used to monitor the progress during CI electrode insertion and to control the intracochlear electrode position after full insertion.

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Flat-Panel Volume Computed Tomography for Cochlear Implant Electrode Array Examination in Isolated Temporal Bone Specimens

Otology & Neurotology ◽

10.1097/01.mao.0000194816.15298.50 ◽

2006 ◽

Vol 27 (4) ◽

pp. 491-498 ◽

Cited By ~ 2

Author(s):

Soenke H. Bartling ◽

Rajiv Gupta ◽

Attila Torkos ◽

Christian Dullin ◽

Grabbe Eckhardt ◽

...

Keyword(s):

Computed Tomography ◽

Cochlear Implant ◽

Temporal Bone ◽

Electrode Array ◽

Flat Panel ◽

Volume Computed Tomography

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Surgical considerations during cochlear implantation: the utility of temporal bone computed tomography

The Journal of Laryngology & Otology ◽

10.1017/s0022215121000232 ◽

2021 ◽

pp. 1-8

Author(s):

Beomcho Jun ◽

Sunwha Song

Keyword(s):

Computed Tomography ◽

Temporal Bone ◽

Cochlear Implantation ◽

Round Window ◽

Three Dimensional ◽

Electrode Placement ◽

Posterior Tympanotomy ◽

Electrode Insertion ◽

Window Approach ◽

Bone Structures

Abstract Objective This paper describes the construction of portals for electrode placement during cochlear implantation and emphasises the utility of pre-operative temporal bone three-dimensional computed tomography. Methods Temporal bone three-dimensional computed tomography was used to plan portal creation for electrode insertion. Results Pre-operative temporal bone three-dimensional computed tomography can be used to determine the orientation of temporal bone structures, which is important for mastoidectomy, posterior tympanotomy and cochleostomy, and when using the round window approach. Conclusion It is essential to create appropriate portals (from the mastoid cortex to the cochlea) in a step-by-step manner, to ensure the safe insertion of electrodes into the scala tympani. Pre-operative three-dimensional temporal bone computed tomography is invaluable in this respect.

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