Inner Ear Enhancement With Delayed 3D-FLAIR MRI Imaging in Vestibular Schwannoma.

Abstract

To evaluate blood-labyrinth barrier permeability using delayed gadolinium enhanced three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) in patients with untreated sporadic vestibular schwannoma (VS) to interrogate the etiopathogenesis of progressive sensorineural hearing loss. Prospective case series. Single institution tertiary care center. Patients with previously untreated small to medium-sized unilateral VS undergoing 3D-FLAIR imaging 10 minutes (immediate) and 5 to 8 hours (delayed) after administration of intravenous gadolinium. Comparison of cochlear and vestibular signal intensity ratios (SIRs) across immediate and delayed images and across the tumor and nontumor ear. Six of eight (75%) patients demonstrated asymmetric enhancement of inner ear structures on delayed contrast-enhanced imaging. Delayed mean cochlea and vestibule SIRs were significantly greater than immediate SIRs (cochlea: 1.91 versus 1.21 [p = 0.02]; vestibule 1.74 versus 1.15 [p = 0.02]). A higher vestibule SIR was statistically significantly associated with poorer pure-tone average and word recognition scores (p = 0.001). Ears with VS exhibited increased enhancement on delayed 3D FLAIR imaging. These findings suggest that alterations in blood-labyrinth barrier permeability may explain progressive sensorineural hearing loss in a subset of patients with untreated VS.