Labyrinthine Signal Intensity on Non-contrast-enhanced 3D-real Inversion Recovery MR Imaging: Correlation with the...

Area of Science:

• Otorhinolaryngology
• Radiology
• Medical Imaging

Background:

• Endolymphatic hydrops (EH) is a condition characterized by excess endolymph in the inner ear.
• Accurate assessment of endolymphatic volume is crucial for diagnosing and managing EH.
• Current imaging techniques may have limitations in directly quantifying endolymphatic volume.

Purpose of the Study:

• To explore the relationship between labyrinthine fluid signal intensity (SI) on non-contrast 3D-real IR imaging and endolymphatic volume measured by contrast-enhanced HYDROPS-Mi2.
• To determine if SI on non-contrast imaging can serve as an indirect biomarker for EH severity.

Main Methods:

• Retrospective analysis of 37 patients (74 ears) with suspected EH.
• Measured endolymphatic volume ratio (%ELvol) using contrast-enhanced HYDROPS-Mi2.
• Measured normalized volume-averaged SI (nSIvol) of labyrinthine fluid using non-contrast 3D-real IR imaging.
• Correlated %ELvol and nSIvol, and used ROC analysis to assess diagnostic performance.

Main Results:

• Vestibular %ELvol was higher and nSIvol lower than in the cochlea (P < 0.001).
• A significant negative correlation was found between %ELvol and nSIvol in both cochlea (Rs = -0.598, P < 0.001) and vestibule (Rs = -0.417, P < 0.001).
• nSIvol was lower in ears with larger %ELvol, suggesting increased hydrops.
• ROC analysis showed moderate diagnostic capability for discriminating EH severity.

Conclusions:

• SI of labyrinthine fluid on non-contrast 3D-real IR imaging is negatively correlated with endolymphatic volume.
• Non-contrast 3D-real IR SI may be a valuable indirect indicator for estimating the degree of endolymphatic hydrops.
• This finding could simplify EH assessment by reducing the need for contrast agents in certain cases.