Clinical significance of endolymphatic imaging after intratympanic gadolinium injection

Conclusion: Using three-dimensional real inversion recovery (3D-real IR) and three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) magnetic resonance imaging (MRI), various degrees of endolymphatic hydrops were observed in the basal and upper turns of the cochlea and in the vestibular apparatus after intratympanic gadolinium (Gd) injection. MRI may contribute to our understanding of inner ear diseases and may be a useful addition to intratympanic drug therapy in the management of inner ear diseases. Objective: To evaluate 3D-real IR MRI and 3D-FLAIR MRI with clinical symptoms and signs in patients with inner ear disease. Patients and methods: Gd was diluted in saline and injected intratympanically in 73 patients with inner ear disease. The endolymphatic space was evaluated with 3-Tesla MRI at I day after the intratympanic Gd injection. Results: 3D-real IR MRI was generally better than 3D-FLAIR MRI in discriminating between the perilymphatic space and endolymphatic space in the cochlear turns and in the vestibular apparatus. However, when Gd concentration was insufficient in the perilymph, it was more difficult to visualize the Gd with 3D-real IR MRI than with 3D-FLAIR MRI. Endolymphatic hydrops was observed using MRI in patients with 'probable' Meniere's disease based on the criteria.