El-Anwar Mohammad Waheed, Fouad Yasser Ahmed, Elgohary Ahmed Fouad, Saber Sameh, Mobasher Mohamed Adel
Department of Otorhinolaryngology-Head and Neck Surgery, Faculty of Medicine, Zagazig University, Zagazig, Egypt.
Department of Radiodiagnosis, Faculty of Medicine, Zagazig University, Zagazig, Egypt.
Int Arch Otorhinolaryngol. 2023 Sep 19;27(4):e565-e570. doi: 10.1055/s-0042-1758213. eCollection 2023 Oct.
Computed tomography (CT) details of the external auditory canal (EAC) are not fully covered in the literature, so building up base for the CT evaluation and description is important. Preoperative details of the EAC are mandatory before any approach or procedure involving the canal. To determine the different dimensions, measurements, and grading of the EAC by CT scan that were not previously published. The CT scans of 100 temporal bones (200 sides) were included. Axial images were acquired with multiplanar reformates to obtain delicate details in coronal and sagittal planes for all subjects. At the EAC entry, the mean vertical length (height) was 7.75 ± 1 mm, and its mean horizontal length (width) was 6.1 ± 0.8. At the bony cartilaginous junction of the EAC, the mean vertical length was 7.88 ± 1 mm, and its mean horizontal length was 6.22 ± 0.9. At the EAC isthmus, the mean vertical length was 6.8 ± 0.97 mm, and its mean horizontal length was 5.2 ± 0.76. At the medial end of the EAC, the mean vertical length was 7.1 ± 0.9 mm, and its mean horizontal length was 5.4 ± 0.85. There were no reported significant differences between right and left sides in all dimensions. Males showed significantly longer vertical and horizontal dimensions of the EAC entry, vertical dimension of the isthmus, and vertical dimension of the medial end of the EAC than females. This study improves otologists and radiologists' awareness of EAC variations in the ear field and can be of help to residents in training.
外耳道（EAC）的计算机断层扫描（CT）细节在文献中并未得到充分涵盖，因此为CT评估和描述建立基础很重要。在进行任何涉及外耳道的手术入路或操作之前，了解其术前细节是必不可少的。
确定通过CT扫描对外耳道进行的不同维度、测量和分级，这些内容此前尚未发表。
纳入了100例颞骨（200侧）的CT扫描数据。对所有受试者均采集了轴向图像，并进行多平面重建以获取冠状面和矢状面的精细细节。
在外耳道入口处，平均垂直长度（高度）为7.75±1mm，平均水平长度（宽度）为6.1±0.8mm。在外耳道的骨软骨交界处，平均垂直长度为7.88±1mm，平均水平长度为6.22±0.9mm。在外耳道峡部，平均垂直长度为6.8±0.97mm，平均水平长度为5.2±0.76mm。在外耳道内侧端，平均垂直长度为7.1±0.9mm，平均水平长度为5.4±0.85mm。所有维度在左右两侧之间均未报告有显著差异。男性在外耳道入口处的垂直和水平维度、峡部的垂直维度以及外耳道内侧端的垂直维度均显著长于女性。
本研究提高了耳科医生和放射科医生对外耳道在耳部领域变异的认识，并有助于培训中的住院医师。
