Prospective MR Evaluation of Endolymphatic Hydrops Using Half-Dose Gadopiclenol

Area of Science:

• Neuroradiology
• Otology
• Medical Imaging

Background:

• Gadopiclenol is a novel macrocyclic gadolinium-based contrast agent (GBCA) with high T1 relaxivity and kinetic stability.
• It was developed to reduce gadolinium dosage and minimize long-term retention risks.
• Its utility for evaluating endolymphatic hydrops (EH) via delayed inner ear imaging remains unexplored.

Purpose of the Study:

• To assess the efficacy of gadopiclenol in delayed contrast-enhanced inner ear imaging for detecting endolymphatic hydrops (EH).
• To evaluate if a reduced dose of gadopiclenol (0.05 mmol/kg) can achieve diagnostic image quality comparable to standard doses of other GBCAs.
• To determine the reliability and image quality metrics (SNR, CNR) of gadopiclenol for diagnosing Ménière disease.

Main Methods:

• Prospective enrollment of 26 patients with Ménière disease criteria.
• Delayed (4-hour) contrast-enhanced 3T inner ear imaging using half-dose gadopiclenol (0.05 mmol/kg).
• Quantitative analysis of Signal-to-Noise Ratio (SNR) and Contrast-to-Noise Ratio (CNR); qualitative assessment of EH, blood-labyrinthine barrier (BLB) permeability, and utricle-saccule discrimination by two neuroradiologists.

Main Results:

• Analysis of 51 ears revealed comparable SNR and CNR between half-dose gadopiclenol (0.05 mmol/kg) and standard-dose gadobenate dimeglumine (0.1 mmol/kg) without statistical significance (P > 0.05).
• Excellent interobserver agreement (κ > 0.80) was achieved for grading EH.
• Gadopiclenol at 0.05 mmol/kg demonstrated reliable detection of clinically concordant EH.

Conclusions:

• Delayed 3D-FLAIR inner ear imaging with gadopiclenol at 0.05 mmol/kg is a reliable method for detecting EH.
• Image quality, assessed quantitatively and qualitatively, is comparable to standard-dose gadobenate dimeglumine.
• This approach supports reduced GBCA dosing for evaluating Ménière disease and EH.