Evaluation of the implanted cochlear implant electrode by CT scanning with three-dimensional reconstruction

Abstract

Conclusions: Computed tomography (CT) scan with three-dimensional (3D) reconstruction of the inner ear provides a more accurate image of the relationship of the electrode within the cochlear canal, with direct demonstration of electrode insertion depth in the cochlea in comparison with X-ray plain film. Objective: This study was designed to evaluate the value of spiral CT scans with 3D reconstruction in determining the insertion site and depth of implanted cochlear implant electrodes. Methods: A total of 172 cochlear implant recipients were involved in this study. The implanted electrodes of all patients were examined by X-ray plain film, and 157 cochlear recipients were examined by spiral CT scans with axial 1 mm image slices. The data from the CT scans were transferred to a workstation for 3D reconstruction (direct volume rendering) of the inner ear. The pseudocolor technique was used to display the electrode. Results: The insertion depth of the electrode could be evaluated indirectly by the X-ray plain film. In contrast, the stereoscopic images from a CT scan with 3D reconstruction of the inner ear demonstrated the shape, position, and insertion depth of the electrode more accurately.

Keywords::

• X-ray plain film
• insertion depth
• spiral CT
• volume rendering technique
• multiplanar reformations
• pseudocolor technique

Acknowledgments

This work was supported by Project 4 of the National Basic Research Program (973 Program) of China (2011CB504504), National High-tech R&D Program (863 Program) of China (2008AA02Z428) and the National Eleventh Five-Year Project for Scientific and Technological Development of China (2007BAI18B13).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.