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. 2011:7962:10.1117/12.878490.
doi: 10.1117/12.878490.

Automatic Identification of Cochlear Implant Electrode Arrays for Post-Operative Assessment

Jack H Noble  1 , Theodore A Schuman  2 , Charles G Wright  3 , Robert F Labadie  2 , Benoit M Dawant  1
Affiliations

Automatic Identification of Cochlear Implant Electrode Arrays for Post-Operative Assessment

Jack H Noble et al. Proc SPIE Int Soc Opt Eng. 2011.

Abstract

Cochlear implantation is a procedure performed to treat profound hearing loss. Accurately determining the postoperative position of the implant in vivo would permit studying the correlations between implant position and hearing restoration. To solve this problem, we present an approach based on parametric Gradient Vector Flow snakes to segment the electrode array in post-operative CT. By combining this with existing methods for localizing intra-cochlear anatomy, we have developed a system that permits accurate assessment of the implant position in vivo. The system is validated using a set of seven temporal bone specimens. The algorithms were run on pre- and post-operative CTs of the specimens, and the results were compared to histological images. It was found that the position of the arrays observed in the histological images is in excellent agreement with the position of their automatically generated 3D reconstructions in the CT scans.

Keywords: Cochlear Implant; Contour Advance; Snake Segmentation.

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Figures

Figure 1
Figure 1
µCT of a cadaveric cochlea in axial view. Delineated are Scala Tympani (red) and Scala Vestibuli (blue).
Figure 2
Figure 2
Model of the Cochlear Contour Advance electrode array. Shown are the surface model (top), the corresponding curve points (middle), and the distances in mm between curve points (bottom).
Figure 3
Figure 3
Implanted electrode array. Curves are used to indicate the electrode contact region (red) and non-contact region (green).
Figure 4
Figure 4
Normalized vector fields produced by GVF (left) and standard gradient computations (right).
Figure 5
Figure 5
Example of GVF field (red arrows) and forward force (blue arrows).
Figure 6
Figure 6
Histological image (left) and CT reconstruction (right) of cochlear implant. The manually localized artifact centerline from CT (blue line) seen in the Scala Tympani (red surface) is distinctly different from actual electrode position in histological image.
Figure 7
Figure 7
Renderings of electrode artifact localization results. Shown are the automatic (red) and manually (green) localized curves for experiments 1–7 (left-to-right, top-to-bottom).
Figure 8
Figure 8
Renderings of array reconstruction results. Shown are the histological image (left), automatic reconstruction (middle) and graphs of the electrode position assessment based on histology (black lines) and automatic reconstruction (red dashed lines) for experiments 1–7 (top-to-bottom).
See this image and copyright information in PMC

References

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