From the Division of Neuroradiology, Department of Radiology (O.I.O.), University of North Carolina School of Medicine, Chapel Hill, North Carolina
Commonwealth Radiology PC (O.I.O.), Richmond, Virginia.
AJNR Am J Neuroradiol. 2024 Apr 8;45(4):511-517. doi: 10.3174/ajnr.A8158.
High-resolution CT is the mainstay for diagnosing an enlarged vestibular aqueduct (EVA), but MR imaging may be an appealing alternative, given its lack of ionizing radiation exposure. The purpose of this study was to determine how reliably MR imaging demonstrates the endolymphatic duct and endolymphatic duct enlargement in hearing-impaired children.
We performed a retrospective review of temporal bone high-resolution CT and MR imaging of hearing-impaired children evaluated between 2017 and 2020. Vestibular aqueduct diameter was measured on high-resolution CT. The vestibular aqueducts were categorized as being enlarged (EVA+) or nonenlarged (EVA-) using the Cincinnati criteria. The endolymphatic ducts were assessed on axial high-resolution CISS MR imaging. We categorized endolymphatic duct visibility into the following: type 1 (not visible), type 2 (faintly visible), and type 3 (easily visible). Mixed-effect logistic regression was used to identify associations between endolymphatic duct visibility and EVA. Interreader agreement for the endolymphatic duct among 3 independent readers was assessed using the Fleiss κ statistic.
In 196 ears from 98 children, endolymphatic duct visibility on MR imaging was type 1 in 74.0%, type 2 in 14.8%, and type 3 in 11.2%; 20.4% of ears were EVA+ on high-resolution CT. There was a significant association between EVA+ status and endolymphatic duct visibility (< .01). Endolymphatic duct visibility was type 1 in 87.1%, type 2 in 12.8%, and type 3 in 0% of EVA- ears and type 1 in 22.5%, type 2 in 22.5%, and type 3 in 55.0% of EVA+ ears. The predicted probability of a type 3 endolymphatic duct being EVA+ was 0.997. There was almost perfect agreement among the 3 readers for distinguishing type 3 from type 1 or 2 endolymphatic ducts.
CISS MR imaging substantially underdiagnoses EVA; however, when a type 3 endolymphatic duct is evident, there is a >99% likelihood of an EVA.
高分辨率 CT 是诊断前庭导水管扩大（EVA）的主要方法，但由于其无电离辐射暴露，磁共振成像（MR 成像）可能是一种有吸引力的替代方法。本研究旨在确定 MR 成像在听力受损儿童中诊断内淋巴管和内淋巴管扩大的可靠性。
我们对 2017 年至 2020 年间评估的听力受损儿童的颞骨高分辨率 CT 和 MR 成像进行了回顾性审查。在高分辨率 CT 上测量前庭导水管直径。根据辛辛那提标准，将前庭导水管分为扩大（EVA+）或未扩大（EVA-）。在内淋巴导管 CISS MR 成像上评估内淋巴导管。我们将内淋巴导管的可视性分为以下 3 种类型：1 型（不可见）、2 型（隐约可见）和 3 型（易见）。使用混合效应逻辑回归确定内淋巴导管可见性与 EVA 之间的关联。3 位独立读者对内淋巴导管的读者间一致性使用 Fleiss κ 统计进行评估。
在 98 名儿童的 196 只耳朵中，MR 成像上内淋巴导管的可视性在 74.0%的耳朵中为 1 型，在 14.8%的耳朵中为 2 型，在 11.2%的耳朵中为 3 型；20.4%的耳朵在高分辨率 CT 上为 EVA+。EVA+状态与内淋巴导管可见性之间存在显著关联（<.01）。EVA-耳朵的内淋巴导管可见性分别为 1 型（87.1%）、2 型（12.8%）和 3 型（0%），EVA+耳朵的内淋巴导管可见性分别为 1 型（22.5%）、2 型（22.5%）和 3 型（55.0%）。3 型内淋巴导管为 EVA+的预测概率为 0.997。3 位读者在区分 3 型与 1 型或 2 型内淋巴导管方面几乎具有完美的一致性。
CISS MR 成像大大低估了 EVA；然而，当出现 3 型内淋巴导管时，EVA 的可能性超过 99%。
