Objective: The present study aimed to evaluate the permeability of the oval window to gadolinium in MD patients.Methodology: Eight patients with MD and other inner ear diseases received a transtympanic injection of 5-fold diluted gadopentetate dimeglumine (Gd-DTPA).3D fluid-attenuated inversion-recovery (3D-FLAIR) and 3D inversion recovery turbo spin echo with real reconstruction (3D-real IR) imaging was performed using a 3-Tesla MRI scanner at 3 h, 6 h, 12 h, and 24 h post-injection.The extent of vestibular endolymphatic hydrops (EH) was determined, and the dynamics of the signal changes in the vestibulum and the cochlear basal turn were evaluated.