Ménière’s disease (MD) is a common peripheral vestibular disorder histopathologically characterized by idiopathic endolymphatic hydrops (ELH), with episodic vertigo, fluctuating hearing loss, tinnitus, or aural fullness as its main clinical symptoms. Although its etiology and pathophysiological mechanisms have not yet been fully elucidated, it is currently believed that MD is associated with disturbed homeostasis of the inner ear, for instance, excessive production and/or impaired absorption of endolymphatic fluid [
1]. Many factors may be involved in this pathological process, among which, anatomical abnormalities have been suggested as a predisposing factor underlying impaired endolymphatic drainage [
1‐
3]. Besides ELH, histological studies have revealed atrophy of the endolymphatic sac (ES), hypoplasia of the vestibular aqueduct (VA), and narrowing of the lumen of the endolymphatic duct (ED) in MD patients [
4‐
6]. Until now, many radiological literatures also have highlighted these pathological findings associated with ES, ED, or VA in patients with MD [
2,
7‐
10].
The VA is a bony canal running from the common crus and opening on the posterior surface of the petrous portion of the temporal bone. The ED takes its origin from the utricle and the saccule in the vestibule and then passes posteriorly into the skeletal tunnel of the VA with transformation to ES. The ES is simply a specialized portion of the posterior fossa dura that contains the resorptive epithelium of the membranous labyrinth [
11]. Atrophy of the ES, hypoplasia of the VA and narrowing of the lumen of the ED has been demonstrated in MD patients by histological investigations [
4‐
6]. Radiological studies have described a correlation between the MD and the lack of a visible ED or VA by using computed tomography (CT), 3D-cone beam CT and magnetic resonance imaging (MRI) [
2,
10,
12,
13]. The first-choice imaging technique to visualize the VA is high resolution CT (HRCT), which typically shows axially a small osseous notch at the posterior margin of the petrous bone, mostly at the level of the horizontal semicircular canal (SCC) or its adjacent superior and inferior levels [
14,
15]. Many MRI sequences have been used to evaluate the ED or VA, including the three-dimensional fluid attenuated inversion recovery (3D-FLAIR), 3D sampling perfection with application optimized contrasts using different flip angle evolutions (3D-SPACE), etc [
3,
16]. Lorenzi et al
. reported that the ED appeared to be statistically less visible on T2-weighted fast spin-echo sequence with fat suppression in patients with MD [
17]. Patel et al
. reported that lack of VA visualization on T2-weighted gradient echo sequence without contrast was statistically significant in MD patients compared to the general population [
18]. Attyé et al
. detected VA abnormalities in both ears of patients with unilateral MD by using 3D-FLAIR sequence [
16]. Recently, using the 3D-SPACE sequence, we also found anatomical differences in endolymphatic drainage system between MD and vestibular migraine in terms of VA visibility and distance between the vertical part of the posterior SCC and the posterior fossa [
19]. Until now, the optimal sequences and parameters remain an open question. Moreover, it is also warranted to investigate the factors influencing MRI-VA visualization, such as osseous VA morphology.
This retrospective study was designed to compare radiological VA visibility using CT and MRI simultaneously in unilateral MD patients. The purpose of this study was to further explore the effect of osseous anatomical variables on visibility of MRI-VA in patients with MD, and the clinical value of VA radiological evaluation in MD was also discussed.