Schurzig Daniel, Timm Max Eike, Lexow G Jakob, Majdani Omid, Lenarz Thomas, Rau Thomas S
a MED-EL Medical Electronics , Hannover Research Center , Hannover , Germany.
b Cluster of Excellence Hearing4all, Dept. of Otolaryngology , Hannover Medical School , Hannover , Germany.
Cochlear Implants Int. 2018 Sep;19(5):268-283. doi: 10.1080/14670100.2018.1460025. Epub 2018 Apr 9.
Within the field of cochlear implantation (CIs), the role of utilizing patient-specific cochlear anatomy for choosing the optimal implant electrode is becoming increasingly important. Unfortunately, performing detailed anatomical measurements of a cochlea using clinical imaging data is rather time consuming and hence difficult to implement into the clinical routine. In order to accelerate clinical cochlear anatomy evaluations, previously developed mathematical models can be adjusted to the patient-specific anatomy by measuring just a few overall cochlear dimensions. However, the accuracy of model-based cochlear anatomy estimations is unclear, and incorrect evaluations may lead to false conclusions regarding the suitability of specific implant electrodes.
Based on 10 cochleae, an error evaluation of various commonly used curve fitting approaches for cochlear shape and duct length approximation was conducted. Spline tracings of the cochlear contours were used as reference values for the various approximations.
Parameterized average cochlear helix models and two of five analytical approaches were found to be suitable for reconstructing the cochlear helical shape and estimating its length.
Spline curve reconstructions are the most accurate and reliable method for assessing patient-specific cochlear geometry, especially in the case of anatomical irregularities. The most accurate results within the group of model-based evaluations still resulted in mean overall cochlear length deviations of approximately 5%.
Spline curve reconstructions appear to be the best option for anatomical diagnostics in clinical practice. Retrospective studies can be performed to further evaluate model-based evaluations.
在人工耳蜗植入（CI）领域，利用患者特异性耳蜗解剖结构来选择最佳植入电极的作用变得越来越重要。不幸的是，使用临床影像数据对耳蜗进行详细的解剖测量相当耗时，因此难以应用于临床常规操作。为了加快临床耳蜗解剖评估，通过仅测量几个耳蜗整体尺寸，可将先前开发的数学模型调整为患者特异性解剖结构。然而，基于模型的耳蜗解剖估计的准确性尚不清楚，不正确的评估可能会导致关于特定植入电极适用性的错误结论。
基于10个耳蜗，对各种常用的用于耳蜗形状和管道长度近似的曲线拟合方法进行了误差评估。耳蜗轮廓的样条追踪用作各种近似的参考值。
发现参数化平均耳蜗螺旋模型和五种分析方法中的两种适用于重建耳蜗螺旋形状并估计其长度。
样条曲线重建是评估患者特异性耳蜗几何形状最准确、最可靠的方法，尤其是在解剖结构不规则的情况下。在基于模型的评估组中，最准确的结果仍导致耳蜗总长度平均偏差约5%。
样条曲线重建似乎是临床实践中解剖诊断的最佳选择。可以进行回顾性研究以进一步评估基于模型的评估。
