From the Department of Radiology, Mayo Clinic, Rochester, Minnesota
From the Department of Radiology, Mayo Clinic, Rochester, Minnesota.
AJNR Am J Neuroradiol. 2022 Sep;43(9):1346-1349. doi: 10.3174/ajnr.A7615. Epub 2022 Aug 25.
The normal appearance of the vestibular aqueduct on postcontrast MR images has not been adequately described in the literature. This study set out to characterize the expected appearance of the vestibular aqueduct, with particular emphasis on the enhancement of the structure on both 3D FSE T1 and 3D-FLAIR sequences.
All MR imaging examinations of the internal auditory canals performed between March 1, 2021, and May 20, 2021, were retrospectively reviewed. All studies included high-resolution (≤0.5-mm section thickness) pre- and postgadolinium 3D FSE T1 with fat-saturated and postgadolinium 3D-FLAIR sequences. Two neuroradiologists independently reviewed the MR images of the vestibular aqueduct for the presence or absence of enhancement on both T1 and FLAIR images and compared the relative intensity of enhancement between sequences. The presence or absence of an enlarged vestibular aqueduct was also noted.
Ninety-five patients made up the patient cohort, of whom 5 did not have postcontrast FLAIR images available (50 women [55.6%]). On both sides, enhancement was significantly more commonly seen on postgadolinium FLAIR (76/180, 42.2%) than on T1 fat-saturated images (41/190, 21.6%) (< .001). The intensity of enhancement was significantly greater on postgadolinium FLAIR images than on T1 fat-saturated images (38.9% versus 3.7%, respectively; < .001).
Enhancement within the vestibular aqueduct is an expected finding on MR imaging and is both more common and more intense on postgadolinium 3D-FLAIR than on T1 fat-saturated sequences. Such enhancement should not be confused with pathology on MR imaging unless other suspicious findings are present.
前庭水管在增强磁共振成像（MR）图像上的正常表现尚未在文献中得到充分描述。本研究旨在描述前庭水管的预期表现，特别强调结构在 3D FSE T1 和 3D-FLAIR 序列上的增强。
回顾性分析 2021 年 3 月 1 日至 2021 年 5 月 20 日期间进行的所有内耳道 MR 成像检查。所有研究均包括高分辨率（≤0.5mm 层厚）增强前和增强后 3D FSE T1 及增强后 3D-FLAIR 序列，脂肪饱和。两名神经放射科医生独立评估前庭水管的 MR 图像，以评估 T1 和 FLAIR 图像上是否存在增强，并比较序列之间增强的相对强度。还注意到前庭水管是否扩大。
95 例患者构成患者队列，其中 5 例患者没有增强后 FLAIR 图像（50 例女性[55.6%]）。双侧增强在增强后 FLAIR（76/180，42.2%）上明显比 T1 脂肪饱和图像（41/190，21.6%）更常见（<0.001）。增强后 FLAIR 图像上的增强强度明显大于 T1 脂肪饱和图像（分别为 38.9%和 3.7%；<0.001）。
在 MR 成像中，前庭水管内的增强是一种预期的发现，与 T1 脂肪饱和序列相比，增强在后增强 3D-FLAIR 上更常见且更强烈。除非存在其他可疑发现，否则不应将这种增强与磁共振成像上的病理学混淆。
