Department of Otorhinolaryngology-Head and Neck Surgery, Ruhr-University Bochum, St. Elisabeth-Hospital Bochum, Bochum, Germany.
Department of Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.
Eur Arch Otorhinolaryngol. 2023 May;280(5):2155-2163. doi: 10.1007/s00405-022-07681-4. Epub 2022 Oct 10.
Enlarged vestibular aqueduct (EVA) is a common finding associated with inner ear malformations (IEM). However, uniform radiologic definitions for EVA are missing and various 2D-measurement methods to define EVA have been reported. This study evaluates VA volume in different types of IEM and compares 3D-reconstructed VA volume to 2D-measurements.
A total of 98 high-resolution CT (HRCT) data sets from temporal bones were analyzed (56 with IEM; [cochlear hypoplasia (CH; n = 18), incomplete partition type I (IPI; n = 12) and type II (IPII; n = 11) and EVA (n = 15)]; 42 controls). VA diameter was measured in axial images. VA volume was analyzed by software-based, semi-automatic segmentation and 3D-reconstruction. Differences in VA volume between the groups and associations between VA volume and VA diameter were assessed. Inter-rater-reliability (IRR) was assessed using the intra-class-correlation-coefficient (ICC).
Larger VA volumes were found in IEM compared to controls. Significant differences in VA volume between patients with EVA and controls (p < 0.001) as well as between IPII and controls (p < 0.001) were found. VA diameter at the midpoint (VA midpoint) and at the operculum (VA operculum) correlated to VA volume in IPI (VA midpoint: r = 0.78, VA operculum: r = 0.91), in CH (VA midpoint: r = 0.59, VA operculum: r = 0.61), in EVA (VA midpoint: r = 0.55, VA operculum: r = 0.66) and in controls (VA midpoint: r = 0.36, VA operculum: r = 0.42). The highest IRR was found for VA volume (ICC = 0.90).
The VA diameter may be an insufficient estimate of VA volume, since (1) measurement of VA diameter does not reliably correlate with VA volume and (2) VA diameter shows a lower IRR than VA volume. 3D-reconstruction and VA volumetry may add information in diagnosing EVA in cases with or without additional IEM.
扩大的前庭水管（EVA）是一种与内耳畸形（IEM）相关的常见发现。然而，目前尚缺乏 EVA 的统一影像学定义，并且已经报道了各种用于定义 EVA 的 2D 测量方法。本研究评估了不同类型 IEM 中的 VA 体积，并比较了 3D 重建的 VA 体积与 2D 测量值。
分析了 98 例颞骨高分辨率 CT（HRCT）数据集（56 例 IEM；[耳蜗发育不全（CH；18 例）、不完全分隔 I 型（IPI；12 例）和 II 型（IPII；11 例）和 EVA（15 例）]；42 例对照）。在轴位图像上测量 VA 直径。通过基于软件的半自动分割和 3D 重建分析 VA 体积。评估组间 VA 体积差异以及 VA 体积与 VA 直径之间的相关性。使用组内相关系数（ICC）评估观察者间可靠性（IRR）。
与对照组相比，IEM 患者的 VA 体积更大。EVA 患者与对照组之间（p<0.001）以及 IPII 与对照组之间（p<0.001）的 VA 体积存在显著差异。IPI 中的 VA 中点（VA midpoint）和镫骨（VA operculum）（VA midpoint：r=0.78，VA operculum：r=0.91）、CH（VA midpoint：r=0.59，VA operculum：r=0.61）、EVA（VA midpoint：r=0.55，VA operculum：r=0.66）和对照组（VA midpoint：r=0.36，VA operculum：r=0.42）中 VA 直径与 VA 体积相关。VA 体积的 IRR 最高（ICC=0.90）。
VA 直径可能不足以估计 VA 体积，因为（1）VA 直径的测量与 VA 体积没有可靠的相关性，并且（2）VA 直径的 IRR 低于 VA 体积。3D 重建和 VA 体积测量可能会在有无其他 IEM 的情况下提供 EVA 诊断的信息。
