Mewes Alexander, Dambon Jan, Brademann Goetz, Hey Matthias
Christian-Albrecht University of Kiel, Kiel, Germany.
Department of Otorhinolaryngology, Head and Neck Surgery, Universitätsklinikum Schleswig-Holstein (UKSH), Campus Kiel, Kiel, Germany.
Eur Arch Otorhinolaryngol. 2025 Jan;282(1):145-154. doi: 10.1007/s00405-024-08917-1. Epub 2024 Aug 30.
Perimodiolar electrode arrays may be positioned regular, over-inserted or under-inserted into the cochlea depending on the cochlear size and shape. The study aimed to examine whether there are differences between these groups in the local curvature along the intracochlear array. Individual curvature variables were developed to categorize the groups and the relationship between the curvature and the angular insertion depth at the electrode tip was analyzed.
The curvature along the intracochlear array was measured in the CBCT image of 85 perimodiolar electrodes of a single type. The mean curvature and the ratio of the mean curvature at contacts E14-16 to the mean curvature at E7-8 (bowing ratio) were calculated across the array, and its true positive rate (TPR) and false positive rate (FPR) were calculated to establish optimal threshold values to categorize the groups.
68.2% of the cases were categorized as regular positioned, 22.4% had an over-insertion and 9.4% had an under-insertion. The mean curvature was significantly weaker with under-insertion (< 342°) than with normal insertion depth (≥ 342°). With an over-insertion, the bowing ratio was < 1 and otherwise > 1. Both the mean curvature and bowing ratio were found to have an optimal threshold value with high TPR (= 1.00) and low FPR (≤ 0.06) for categorizing under-insertion and over-insertion, respectively.
Curvature analysis is a useful tool to assess if a perimodiolar electrode array has been inserted deep enough into the cochlea. Independent of critical anatomical landmarks, over-inserted arrays and under-inserted arrays could be well categorized by using individual curvature variables. The results need to be validated using additional data sets.
根据耳蜗的大小和形状，蜗周电极阵列在插入耳蜗时可能位置正常、过度插入或插入不足。本研究旨在探讨这些组在沿耳蜗内电极阵列的局部曲率方面是否存在差异。开发了个体曲率变量以对这些组进行分类，并分析了曲率与电极尖端角度插入深度之间的关系。
在85个单一类型的蜗周电极的CBCT图像中测量沿耳蜗内电极阵列的曲率。计算整个阵列的平均曲率以及触点E14 - 16处的平均曲率与E7 - 8处的平均曲率之比（弯曲率），并计算其真阳性率（TPR）和假阳性率（FPR）以建立对这些组进行分类的最佳阈值。
68.2%的病例被分类为位置正常，22.4%为过度插入，9.4%为插入不足。插入不足（< 342°）时的平均曲率明显低于正常插入深度（≥ 342°）时的平均曲率。过度插入时，弯曲率< 1，否则> 1。发现平均曲率和弯曲率分别具有用于分类插入不足和过度插入的最佳阈值，其真阳性率高（= 1.00）且假阳性率低（≤ 0.06）。
曲率分析是评估蜗周电极阵列是否已足够深地插入耳蜗的有用工具。独立于关键解剖标志，通过使用个体曲率变量可以很好地对过度插入和插入不足的阵列进行分类。结果需要使用额外的数据集进行验证。
