Diagnostic role of cone beam computed tomography for the position of straight array

Abstract

Objective: To assess the usefulness of cone beam computed tomography (CBCT) for characterizing electrode insertion and evaluate the influence of electrode insertion status on post-cochlear implantation (CI) outcomes.

Design: Twenty-six ears with post-CI CBCT scans were included. The devices were MED-EL Flex28 (n = 21) and Nucleus slim straight (n = 5). The parameters including cochlear duct length (CDL), insertion depth angle (IDA), insertion length of electrode (IL), and cochlear coverage (CC) were analyzed and compared with aided pure-tone threshold (PTA) with implant in free field, and open-set sentence score.

Results: The mean CDL was 36.8 ± 1.4 mm. Electrode array was dislocated into scala tympani in two ears. The mean IL and IDA were 26.5 ± 1.9 mm and 541.4 ± 70.2°. The mean linear CC (IL/CDL, 0.73 ± 0.06) was larger than the mean angular CC (IDA/900, 0.60 ± 0.08). The CBCT parameters showed correlation one another. While the aided pure-tone threshold was correlated with IL and IDA, there were no significant correlations in the open-set sentence score. For the postlingually deaf patients with single electrode (Flex 28), the sentence score had no significant correlation and the aided PTA was positively correlated with IL (R = 0.517, p = .028).

Conclusions: This study validated the CBCT evaluating the electrode array position. The CBCT could be helpful for the preoperative selection of the optimal array and prediction of the CC.

Chinese abstract

目的：评估锥形束计算机断层扫描（CBCT）对表征电极插入的有用性, 并评估电极插入状态对人工耳蜗植入（CI）结果的影响。

设计：接受植入后CIBCT扫描的二十六个耳被归入研究。人工耳蜗装置是MED-EL Flex28（n = 21）和Nucleus 细直型（n = 5）。被分析的参数包括人工耳蜗管长度（CDL）、插入深度角（IDA）、电极插入长度（IL）和耳蜗覆盖率（CC）。对于自由场中的耳蜗植入, 这些参数被分析并与辅助纯音阈值（PTA）和开放式句子评分相比较 。

结果：平均CDL为36.8 ± 1.4 mm。电极阵列在两耳中位移至鼓室。平均IL和IDA分别为26.5 ± 1.9 mm和541.4 ± 70.2°。平均线性CC（IL/CDL, 0.73 ± 0.06）大于平均角CC（IDA/900, 0.60 ± 0.08）。 CBCT参数显示相互关联。虽然辅助纯音阈值与IL和IDA相关, 但是在开放式句子评分中没有显著的相关性。对于具单个电极（Flex 28）的后聋患者, 句子评分没有显著相关性, 而辅助PTA与IL呈正相关（R = 0.517, p = 0.028）。

结论：本研究验证了CBCT评估电极阵列位置。 CBCT可能有助于术前选择最佳阵列和预测耳蜗覆盖率。

Keywords:

• Cochlear implants
• cone-beam computed tomography
• cochlear duct
• implanted electrode

View correction statement:

Correction to: An et al., Diagnostic role of cone beam computed tomography for the position of straight array

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning [NRF-2015R1C1A1A02036457]. This study was supported by a National Research Foundation of Korea (NRF) Grant funded by the Korean Government [NRF-2015R1C1A2A01055438]. This work was supported by the new faculty research fund of Ajou University School of Medicine.