Three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging findings in patients with sudden sensorineural hearing loss

Objective. To evaluate the inner ear in sudden sensorineural hearing loss (SNHL) using three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) magnetic resonance imaging (MRI) at 3 Tesla (T). Background: 3D-FLAIR MRI has recently been developed to detect high concentrations of protein or hemorrhage. Application of this method to sudden SNHL has not been described. Methods: We used 3D-FLAIR at 3 T with and without gadolinium enhancement to evaluate eight patients with sudden SNHL. Results: In four of eight ears with idiopathic sudden SNHL, high precontrast signals were observed within the inner ear on 3D-FLAIR. The high-signal areas observed on 3D-FLAIR were not detected by T1- or T2-weighted MRI in any of these patients. In one of these four ears, significant gadolinium enhancement was observed on 3D-FLAIR. Conclusion: Half the patients with sudden SNHL examined had high signals in the SNHL-affected ear on 3D-FLAIR at 3 T. High precontrast signals in the inner-ear fluid space may reflect minor hemorrhage, or an increased concentration of protein that had passed through blood vessels with increased permeability, or had originated from disrupted cells in the inner ear. Gadolinium enhancement in one ear suggested the breakdown of the blood-labyrinth barrier. 3D-FLAIR MRI should contribute markedly to the elucidation of pathologic conditions in the inner ears of patients with idiopathic sudden SNHL.