3D-FLAIR imaging with optimized scan parameters to visualize endolymphatic hydrops with intravenous gadolinium-based contrast media

Objective: To explore the optimal imaging parameters, including the optimal scan time and scan angle, of 3D-FLAIR imaging in labyrinthine for patients with vertigo and sensorineural hearing loss. Design: A prospective clinical study. Setting: Academic-tertiary center. Participants: Twenty-two patients with unilateral vertigo and sensorineural hearing loss were prospectively reviewed between July 2018 and June 2019. Main outcome measures: The corresponding signal-intensity-ratios and contrast-to-noise-ratios of these images acquired at different time points after the administration of gadolinium contrast agent at double dose were obtained on the 3D-FLAIR images. The scan angles, aiming to obtain the relative maximum areas of the saccule, utricle and lateral semicircular canal displayed at the same level, were also evaluated with the anterior skull base in the sagittal position. Results:3D-FLAIR images with double-dose injection of gadolinium contrast acquired at 6 hours post-injection showed the strongest image contrast in the cochlea compared to those at 4 and 8 hours (affected ear: 2.05±0.72 vs 1.85±0.76 vs 1.79±0.60, unaffected ear: 1.97±0.68 vs 1.59±0.28 vs 1.57±0.31). The significantly higher CNR values were shown at 6 hours in both the affected and unaffected ears than those acquire at other time points (P <0.05). In addition, the optimal angles ranging from 6.20 to 13.6 degrees (mean:10.74±2.24 degrees; P<0.01) were obtained. Conclusion: The optimal scan time was found at 6 hours after injecting contrast agent at double-dose. Together with the best scan angle obtained, the EH can be accurately assessed on 3D-FLAIR images.