Vestibular Aqueduct Morphology and Meniere's Disease—Development of the “Vestibular Aqueduct Score” by 3D Analysis

Abstract

Improved radiological examinations with newly developed 3D models may increase understanding of Meniere's disease (MD). The morphology and course of the vestibular aqueduct (VA) in the temporal bone might be related to the severity of MD. The presented study explored, if the VA of MD and non-MD patients can be grouped relative to its angle to the semicircular canals (SCC) and length using a 3D model. Scans of temporal bone specimens (TBS) were performed using micro-CT and micro flat panel volume computed tomography (mfpVCT). Furthermore, scans were carried out in patients and TBS by computed tomography (CT). The angle between the VA and the three SCC, as well as the length of the VA were measured. From these data, a 3D model was constructed to develop the vestibular aqueduct score (VAS). Using different imaging modalities it was demonstrated that angle measurements of the VA are reliable and can be effectively used for detailed diagnostic investigation. To test the clinical relevance, the VAS was applied on MD and on non-MD patients. Length and angle values from MD patients differed from non-MD patients. In MD patients, significantly higher numbers of VAs could be assigned to a distinct group of the VAS. In addition, it was tested, whether the outcome of a treatment option for MD can be correlated to the VAS.

The association between high jugular bulb and mastoid pneumatization in adults

“…The jugular bulb related vestibular aqueduct dehiscence is the most common JB-related inner ear dehiscence, which has been associated with Meniere disease or endolymphatic hydrops. It can be postulated that the interruption of VA may occur when the HJB reaches to a sufficient height, such as above the lower edge of the IAC, which pathological feature of VA related HJB ( 25 , 26 ). Conductive hearing loss is caused by the JB touching the tympanic membrane or extending to a small portion of the ossicular chain and round window.…”

Volumetry improves the assessment of the vestibular aqueduct size in inner ear malformation

“…It has been shown in other studies, that standardized radiological measurements may give new insights into the etiopathology and prognosis of diseases associated with the endolymphatic duct and sac, such as Meniere’s disease [ 44 – 46 ]. When transferring such findings into a clinical context, algorithms for standardized detection of radiological features may gain importance [ 47 ]. The present study is limited by the sample sizes of the individual malformation types.…”