Würfel Waldemar, Lanfermann Heinrich, Lenarz Thomas, Majdani Omid
Department of Otorhinolaryngology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
Institute for Neuroradiology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
Hear Res. 2014 Oct;316:65-72. doi: 10.1016/j.heares.2014.07.013. Epub 2014 Aug 11.
Indications for cochlear implants are determined by audiological and medical considerations. Clinical imaging is therefore an integral element for anatomical evaluation in terms of medical considerations. Several authors have discussed the variability of cochlear shape, especially cochlear length. Cochlear length is, however, an increasingly recognized parameter in terms of preoperative evaluation. This study introduces a methodology to determine individual cochlear length in clinical setting by using Cone Beam Computed Tomography. Cochlear length determination was performed retrospectively with an OsiriX curved 3D Multiplanar Reconstruction tool on subjects who underwent temporal bone imaging from January 2011 to February 2013. Cochlear length was defined as the spiral route from the center-distal point of the bony round window along the lateral wall towards the helicotrema, which is the endpoint of the measurement. Cochlear length was measured in 436 temporal bones (218 left ears, 218 right ears, 218 subjects). The mean cochlear length was 37.6 mm (SD: ± 1.93 mm), median was 37.6 mm, range 32-43.5 mm. The cochlear length had a normal distribution. A significant difference was found between cochlear length by gender (p < .0001), but not between the left and right cochlea (p = .301) or according to age. Consideration of the cochlear length in clinical data may be an insufficiently represented parameter in cochlear implant treatment. Literature shows the impact of electrode insertion depth on residual hearing preservation and speech performance. Individual evaluation of the cochlear implant electrode choice may be the next step in personalized cochlear implant treatment as a valuable addition to existing audiological and surgical evaluation. The cochlear length determination methodology presented herein is a reproducible and clinically available parameter. Indeed, revealing a significant cochlear length span width, especially according to gender differences, may be assumed as hardly ignorable.
人工耳蜗植入的适应证由听力学和医学因素决定。因此，临床影像学是医学因素解剖学评估的一个重要组成部分。几位作者讨论了耳蜗形状的变异性，尤其是耳蜗长度。然而，耳蜗长度在术前评估中是一个越来越受认可的参数。本研究介绍了一种在临床环境中使用锥形束计算机断层扫描来确定个体耳蜗长度的方法。对2011年1月至2013年2月接受颞骨成像的受试者，使用OsiriX曲面3D多平面重建工具进行回顾性耳蜗长度测定。耳蜗长度定义为从骨圆窗中心远端点沿外侧壁朝向蜗孔的螺旋路径，蜗孔为测量终点。在436块颞骨（218只左耳、218只右耳、218名受试者）中测量耳蜗长度。平均耳蜗长度为37.6mm（标准差：±1.93mm），中位数为37.6mm，范围为32 - 43.5mm。耳蜗长度呈正态分布。发现耳蜗长度在性别上有显著差异（p <.0001），但左右耳蜗之间（p = 0.301）或按年龄划分均无显著差异。在临床数据中考虑耳蜗长度可能是人工耳蜗植入治疗中一个未得到充分体现的参数。文献表明电极插入深度对残余听力保留和言语表现有影响。对人工耳蜗电极选择进行个体评估可能是个性化人工耳蜗植入治疗的下一步，作为现有听力学和手术评估的有价值补充。本文介绍的耳蜗长度测定方法是一个可重复且临床可用的参数。事实上，揭示出显著的耳蜗长度跨度宽度，尤其是根据性别差异，可能被认为是不可忽视的。
