Significance of high signal intensity in the endolymphatic duct on magnetic resonance imaging in ears with otological disorders.

Background: High signal intensity in the endolymphatic duct (ED) is occasionally observed on magnetic resonance imaging (MRI) in ears that have otological disorders.
Objective: The signal intensity (SI) in the ED on post-contrast MRI was investigated in subjects with various otological disorders, and the meaning of high SI in the ED was evaluated.
Material and Methods: 392 patients with otological disorders and 21 controls without otological symptoms underwent 3 T MRI. The SIs of the ED and the cerebellum were measured, the SI ratio (SIR) was calculated, and ears with SIR ≥4 were identified.
Results: A high SIR was identified in the ED of 3.7% of ears affected by definite Meniere's disease (dMD), 100% of ears affected by large vestibular aqueduct syndrome (LVAS), and 7.1% of ears with no otological symptoms. On the whole, a significant relationship was found between the existence of vestibular or cochlear EH and the SIR in the ED.
Conclusion: The MRI finding of high SI in the ED may indicate the mechanism of inner ear disturbances in ears with otological disorders, especially in those with LVAS, and it may suggest an underlying disorder in some ears in which otological symptoms are not apparent.