Prospective MR Evaluation of Endolymphatic Hydrops at Multiple Flip Angles Using Single-Dose Gadolinium Contrast

Area of Science:

• Radiology
• Otolaryngology
• Medical Imaging

Background:

• Ménière disease (MD) diagnosis relies on advanced imaging techniques.
• Optimizing 3D-FLAIR MRI protocols for inner ear imaging is crucial.
• Flip angle selection is a key challenge in 3D-FLAIR for MD.

Purpose of the Study:

• To evaluate the three most common flip angle parameters for 3D-FLAIR inner ear imaging.
• To compare image quality using constant flip angle (CFA) 120°, CFA 140°, and variable flip angle (VFA).
• To determine the optimal flip angle for detecting endolymphatic hydrops (EH) in MD patients.

Main Methods:

• Prospective enrollment of 16 MD patients based on American Academy of Otolaryngology criteria.
• Delayed inner ear MRI at 3T using CFA 120°, CFA 140°, and VFA after gadolinium contrast.
• Quantitative analysis of contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR).
• Qualitative assessment of blood-labyrinthine barrier (BLB) permeability, utricle-saccule discrimination, and EH by neuroradiologists.

Main Results:

• CFA 140° yielded significantly higher SNR of the perilymphatic space and CNR of the endolymphatic space compared to CFA 120° and VFA (P < .05).
• Improved visualization of EH, utricle-saccule complex, and BLB permeability was observed with CFA 140° (P < .05).
• Excellent interobserver agreement (κ > 0.80) was achieved in assessments.

Conclusions:

• 3D-FLAIR inner ear imaging with CFA 140° and single-dose IV gadolinium contrast at 3T is a reliable method for detecting EH.
• CFA 140° provides superior image quality for evaluating inner ear structures in MD.
• Optimized flip angle selection enhances diagnostic accuracy for Ménière disease.