Substantially Higher Vestibular Hydrops Agreement in Older Patients Assessed by Non-contrast vs. Contrast-enhanced MRI: A Preliminary Study

PURPOSE: This preliminary study aimed to investigate the agreement in endolymphatic hydrops (EH) grading between high-resolution non-contrast and contrast-enhanced HYDROPS (HYbriD of Reversed image Of Positive endolymph signal and native image of positive perilymph Signal) techniques in the same subjects and to clarify the effect of patient age on the concordance between the 2 methods. METHODS: A retrospective study was performed on 12 patients (24 ears; age range: 24-76 years) suspected of EH, all of whom underwent both non-contrast and 4-hour post-contrast 3T MRI. EH in the cochlea and vestibule was graded by the Nakashima scale. Agreement analyses were assessed using the weighted Cohen's kappa (κ). Statistical significance, including the difference between Younger (24-54 years) and Older (57-76 years) patient subgroups, was determined via bootstrap analysis. RESULTS: The overall agreement between non-contrast and contrast-enhanced methods was fair for both the cochlea (κ = 0.343) and vestibule (κ = 0.398). Subgroup analysis revealed a significant age-related difference in vestibular agreement (P = 0.005), showing substantial agreement in the Older group (κ = 0.795) but only slight agreement in the Younger group (κ = 0.113). No significant age-related difference was found for cochlear agreement. Quantitatively, the non-contrast method demonstrated a significantly lower contrast-to-noise ratio compared to the contrast-enhanced method. CONCLUSION: The concordance between non-contrast and contrast-enhanced MRI for EH assessment is site- and age-dependent. The substantially higher agreement found in older patients suggests that age-related physiological changes facilitate non-contrast visualization. However, caution is advised when interpreting non-contrast findings in younger patients due to potential risks of vestibular overestimation and cochlear underestimation. Given the preliminary nature and small sample size of this study, further investigations with larger cohorts are necessary to validate these findings and the appropriateness of age-based categorization.