Detection of intralabyrinthine abnormalities using post-contrast delayed 3D-FLAIR MRI sequences in patients with acute vestibular syndrome

Purpose 3D-FLAIR sequences with delayed acquisition after contrast medium injection have demonstrated new insights into blood-labyrinthine barrier (BLB) abnormalities in various diseases. The aim of this study was to assess the BLB in patients referred with unilateral acute vestibular syndrome (UAVS). Materials and methods In this retrospective multicenter imaging study, we performed 3D-FLAIR and steady-state free precession (SSFP) sequences 4 h after contrast medium administration in 26 healthy volunteers and in 30 patients with UAVS. Two radiologists, blinded to the clinical data, independently assessed the asymmetrical enhancement of the labyrinthine structures and the vestibular nerve on 3D-FLAIR sequences, and the signal of the labyrinthine structures on SSFP sequences. Inter-reader agreement tests were performed. Results An asymmetrical enhancement of the semicircular canals was observed in 26 out of 30 ears (86.6%, p < 0.001) and never observed in healthy subjects. An asymmetrical enhancement of the vestibular nerve was never observed in either patients or healthy subjects. An asymmetrical enhancement of the cochlea was observed on the 3D-FLAIR sequence in 6 out of 30 ears only in the patients’ group (20%, p = 0.03) and always associated with an enhancement of at least one semicircular canal. A low signal on SSFP sequences was observed only in 11 out of 30 symptomatic ears (36.7%, p < 0.001), involving the utricle in 7 ears and the superior semicircular canal in 4 ears. Conclusion Patients with typical UAVS presented with semicircular canal enhancement on MRI, while an asymmetrical enhancement of the vestibular nerve was not displayed. Trial registration NCT02529475 Key Points • Patients with typical vestibular neuronitis presented with semicircular canal enhancement on MRI in 87% of cases. • An enhancement of the vestibular nerve was never displayed.