Aschendorff A, Kubalek R, Hochmuth A, Bink A, Kurtz C, Lohnstein P, Klenzner T, Laszig R
Department of Otorhinolaryngology, University of Freiburg, Freiburg, Germany.
Acta Otolaryngol Suppl. 2004 May(552):46-9.
The purpose of this study was to evaluate the feasibility and usability of different radiologic methods (single-slice computed tomography (CT), multi-slice CT and rotational tomography (RT)) for assessment of the position of cochlear implant electrodes. Cochlear implants in an isolated human temporal bone and in a complete formalin-fixed cadaver head were examined and the electrode position was determined. Subsequently, the labyrinth bone was isolated out of the cadaver head and histologically examined to compare the results of histology with imaging. Single-slice CT reliably identifies the electrode inside the human cochlea; however, due to the technically based large electrode artifact its position inside the cochlear spaces (e.g. electrode position in scala tympani or scala vestibuli) cannot be detected. Multi-slice CT of the cadaver head also showed artifacts that complicate the assessment of electrode position. Using RT the electrode artifact is small and therefore the electrode position within the cochlear spaces, scala tympani versus scala vestibuli, can be assessed. This technique was also applicable in a complete cadaver head, which is in contrast with former studies. In conclusion, CT allows the identification of electrode arrays inside the human cochlea. Multi-slice CT permits a much more precise depiction of the electrode inside the cochlea. RT alone has minimized electrode artifacts to a high extent and permits the assessment of the electrode position within the scala tympani or scala vestibuli. As RT was performed successfully in a complete cadaver head, further studies for evaluation of the intracochlear electrode position can now be performed in patients.
本研究的目的是评估不同放射学方法（单层计算机断层扫描（CT）、多层CT和旋转断层扫描（RT））用于评估人工耳蜗电极位置的可行性和可用性。对置于孤立的人类颞骨以及完整的福尔马林固定尸头中的人工耳蜗进行检查，并确定电极位置。随后，从尸头中分离出迷路骨并进行组织学检查，以将组织学结果与影像学结果进行比较。单层CT能够可靠地识别出人类耳蜗内的电极；然而，由于技术原因导致的较大电极伪影，无法检测到其在耳蜗间隙内的位置（例如鼓阶或前庭阶中的电极位置）。尸头的多层CT也显示出伪影，这使得电极位置的评估变得复杂。使用RT时，电极伪影较小，因此可以评估电极在耳蜗间隙（鼓阶与前庭阶）内的位置。与以前的研究相比，该技术也适用于完整的尸头。总之，CT能够识别出人类耳蜗内的电极阵列。多层CT能够更精确地描绘耳蜗内的电极。单独使用RT已在很大程度上减少了电极伪影，并能够评估电极在鼓阶或前庭阶内的位置。由于RT在完整尸头上成功实施，现在可以在患者中开展进一步研究以评估耳蜗内电极位置。
