Zou Jing, Hannula Markus, Lehto Kalle, Feng Hao, Lähelmä Jaakko, Aula Antti S, Hyttinen Jari, Pyykkö Ilmari
Hearing and Balance Research Unit, Field of Oto-laryngology, School of Medicine, University of Tampere, Tampere, Finland; Department of Otolaryngology-Head and Neck Surgery, Center for Otolaryngology-Head & Neck Surgery of Chinese PLA, Changhai Hospital, Second Military Medical University, Shanghai, China.
Department of Electronics and Communications Engineering, and BioMediTech, Tampere University of Technology, Tampere, Finland.
Hear Res. 2015 Aug;326:59-65. doi: 10.1016/j.heares.2015.04.005. Epub 2015 Apr 25.
Cone-beam computed tomography (CBCT) plays a key role in cochlear implantation in both planning implantation before surgery and quality control during surgery due to the high spatial resolution and convenience of application in the operation theater. We recently designed a novel, highresolution cone-beam acquisition system that has been tested in temporal bones with cochlear implantation to identify the scalar localization of the electrode arrays. The current study aimed to verify the reliability of the experimental CBCT set-up using high-resolution in vitro X-ray microtomography (μCT) imaging as a reference. Nine human temporal bones were studied by inserting a straight electrode of a cochlear implant using the round window approach followed by sequential imaging using experimental CBCT and μCT with and without 1% iodine as the contrast agent. In the CBCT images, the electrodes were located in the scala tympani and near the lateral wall in all temporal bones. In the μCT images, the cochlear fine structures, including Reissner's membrane, stria vascularis, spiral ligament, basilar membrane, spiral limbus, osseous spiral lamina, and Rosenthal's canal that hosts the spiral ganglion cells, were clearly delineated; the electrode array avoided the lateral wall of the scala tympani in the hook region and then ran along the lateral wall of the scala tympani without any exception, a feature that was also detected in a temporal bone with ruptures in the basilar and Reissner's membranes. In conclusion, the current in vitro μCT imaging system produced high-quality images that could demonstrate the fine cochlear structures faithfully and verify the reliability of a novel experimental CBCT set-up aimed for clinical application in identifying the scalar localization of the electrode array. The straight electrode is safe for cochlear structures with low risk of translocation and is suitable for atraumatic implantation, although a large gap between the contacts and the modiolus exists.
由于具有高空间分辨率以及在手术室应用的便利性，锥形束计算机断层扫描（CBCT）在人工耳蜗植入手术前的规划和手术期间的质量控制中都发挥着关键作用。我们最近设计了一种新型的高分辨率锥形束采集系统，该系统已在用于人工耳蜗植入的颞骨中进行测试，以确定电极阵列的蜗管定位。本研究旨在以高分辨率体外X射线显微断层扫描（μCT）成像为参考，验证实验性CBCT设置的可靠性。对九个人类颞骨进行了研究，采用圆窗法插入人工耳蜗的直电极，然后使用实验性CBCT和μCT进行连续成像，成像时分别使用和不使用1%碘作为对比剂。在CBCT图像中，所有颞骨中的电极均位于鼓阶且靠近外侧壁。在μCT图像中，耳蜗的精细结构清晰可辨，包括Reissner膜、血管纹、螺旋韧带、基底膜、螺旋缘、骨螺旋板以及容纳螺旋神经节细胞的Rosenthal管；电极阵列在钩区避开鼓阶外侧壁，然后无一例外地沿着鼓阶外侧壁走行，在基底膜和Reissner膜有破裂的一个颞骨中也检测到了这一特征。总之，当前的体外μCT成像系统产生了高质量的图像，能够如实地显示耳蜗的精细结构，并验证了一种旨在用于临床的新型实验性CBCT设置在识别电极阵列蜗管定位方面的可靠性。直电极对耳蜗结构安全，移位风险低，适合无创植入，尽管电极触点与蜗轴之间存在较大间隙。
