3 Tesla magnetic resonance imaging obtained 4 hours after intravenous gadolinium injection in patients with sudden deafness

Abstract

Conclusion: 3 Tesla (3T) magnetic resonance imaging (MRI) performed 4 h after intravenous gadolinium (Gd) injection provides sufficient anatomic resolution of the inner ear fluid spaces in sudden deafness. The signal intensity ratio (SIR) between the cochlea and cerebellum may be a good indicator of disruption of the blood–labyrinthine barrier. Objectives: We evaluated the inner ear 4 h after intravenous Gd injection to determine whether 3T MRI enables the acquisition of images of the affected inner ear in sudden deafness. Methods: Ten patients underwent 3T MRI scanning 4 h after intravenous Gd injection. Three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) MRI was performed. Results: The SIR varied from 0.45 to 2.17 in 11 affected ears and from 0.43 to 1.48 in 9 unaffected ears. The difference of contrast (affected ear vs unaffected ear) could be detected in five of the nine patients with unilateral sudden deafness. The Gd distribution was recognized in the vestibule of 10 affected ears and in the cochlea of 5 affected ears, in which no significant hydrops was observed. In the remaining vestibules and cochleas of affected ears, the Gd enhancement was too faint to evaluate the endolymphatic hydrops.

Keywords::

• Inner ear fluid spaces
• blood–labyrinthine barrier
• gadolinium distribution
• fluid-attenuated inversion recovery
• endolymph
• perilymph
• signal intensity ratio

Acknowledgments

This study was supported by research grants from the Ministry of Health, Labour and Welfare in Japan. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.