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