Improved measurement of the cochlea length using the flat-panel volume CT with secondary reconstructions

Introduction Cochlea implants (CI) can restore speech perception in patients with severe hearing loss or deafness. Studies have shown that the length and type of the electrode array and the anatomy of the cochlea have an impact on the clinical outcome. Hence, an exact preoperative and postoperative measurement of 2TL (2 turns of the cochlea) and the CDL (cochlear duct length) to select the optimal CI electrode array and to enable anatomically based frequency mapping becomes more and more important.

Methods In this study in temporal bones and in pre- and postoperative images of a patient cohort it was investigated whether the accuracy of the measurements of 2TL and CDL is improved by flat panel volume computer tomography with secondary reconstructions (fpVCT_SEKO) and 3D-curved multiplanar reconstruction (MPR). Results were compared to measurements in routine fpVCT, multislice-CT (MSCT) and μ-CT as a reference test.

Results A manual 2TL- or CDL-measurement provides acceptable to excellent intraobserver-variability regardless of the modality. The study in the temporal bones showed significant differences of 2TL and CDL between fpVCT_SEKO, fpVCT and MSCT. Comparing fpVCT_SEKO with the reference method μCT yielded no differences for 2TL and small discrepancies in CDL. These results were confirmed in pre- and postoperative images. Postoperatively CDL is slightly underestimated in fpVCT_SEKO most likely due to motion artifacts.

Conclusion: The use of fpVCT_SEKO combined with manual measurements using 3D-curved MPR improves determination of 2TL and CDL compared to MSCT. This approach might contribute to a more accurate preoperative planning and optimized, individual CI-fitting postoperatively.

Poster-PDF A-1080.pdf

Publication History

Article published online:
13 May 2021