Department of Otolaryngology, Al Faisal University, King Saud Medical City, Riyadh, Saudi Arabia.
Department of Otolaryngology, King Saud Medical City, Riyadh, Saudi Arabia.
J Int Adv Otol. 2024 Mar 27;20(2):108-112. doi: 10.5152/iao.2024.231191.
Cochlear size variation was first reported in 1884, and since then, there have been various reports confirming the same. Yet, there is no single report that has displayed the wide variations in the cochlear size in a single layout capturing the cochlea in the oblique coronal view/ cochlear view. Basal turn diameter (A-value) was measured in the oblique coronal plane using the OTOPLAN® otological preplanning tool in 104 computed tomography (CT) scans of the temporal bones of cochlear implant (CI) recipients in a tertiary CI center. All CT scans with an image resolution of at least 0.5 mm and identified as having cochleae with normal anatomy were included in this study. A 3-dimensional (3D) segmentation was performed using the 3D slicer and visualized to evaluate the impact of cochlear size on the number of turns studied. The A-value was found to vary between 7.3 mm and 10.4 mm among the studied patients. Three-dimensional segmentation of the inner ear revealed only 2 turns of the cochlea in 4 ears, with A-values of 7.3, 8.8, 7.8, and 7.7 mm. One ear had only 11 /2 turns of the cochlea, with an A-value of 7.9 mm. As a further advancement in the assessment of cochlear size as determined by the A-value, 3D segmentation of the complete inner ear provides a full picture of the number of cochlear turns. Three-dimensional segmentation of the entire inner ear could help improve the preoperative planning of CI surgery and have implications for electrode array selection. Cochlear size could be a predictor of the number of cochlear turns, even in cases that look normal from the radiological findings. The findings of this study could help in improving the preoperative planning for a more successful CI surgery by differentiating between the normal and abnormal cochlea.
耳蜗大小的变异于 1884 年首次报道，此后，有各种报道证实了这一点。然而，目前还没有一份报告能够以单一的布局显示耳蜗大小的广泛变化，同时捕捉到斜冠状视图/耳蜗视图中的耳蜗。在一家三级人工耳蜗植入 (CI) 中心，使用 OTOPLAN®耳科学术前规划工具，在 104 例颞骨 CT 扫描的斜冠状平面上测量耳蜗植入患者的基底转直径 (A 值)。所有 CT 扫描的图像分辨率至少为 0.5 毫米，且被识别为具有正常解剖结构的耳蜗都包含在本研究中。使用 3D 切片机进行 3 维 (3D) 分割，并可视化以评估耳蜗大小对研究转数的影响。研究患者的 A 值在 7.3 毫米至 10.4 毫米之间变化。内耳的 3D 分割仅在 4 只耳朵中显示耳蜗有 2 转，A 值分别为 7.3、8.8、7.8 和 7.7 毫米。一只耳朵只有 11 /2 转的耳蜗，A 值为 7.9 毫米。作为 A 值确定的耳蜗大小评估的进一步进展，完整内耳的 3D 分割提供了耳蜗转数的全貌。整个内耳的 3D 分割有助于改善 CI 手术的术前规划，并对电极阵列的选择有影响。耳蜗大小可能是耳蜗转数的预测因素，即使从影像学发现来看是正常的。本研究的结果有助于通过区分正常和异常耳蜗来改善 CI 手术的术前规划，从而使手术更成功。
