Photon-counting CT based vestibular aqueduct trajectory analysis for the assessment of Ménière's disease endotypes and hearing loss.

BACKGROUND

Ménière's disease (MD) is a heterogeneous inner ear disorder, and imaging-based endotype identification may inform prognosis and personalized management. The vestibular aqueduct (VA) is a candidate imaging biomarker, and photon-counting CT (PCCT) offers high-resolution depiction of temporal bone microanatomy. This study evaluated PCCT-derived VA morphometric parameters as imaging biomarkers for MD endotype identification and hearing loss assessment.

METHODS

In this retrospective study, 106 patients (212 ears) underwent temporal bone PCCT and 3.0-T 3D-FLAIR MRI. PCCT parameters included angular trajectory of the VA (ATVA), VA visibility grade, morphologic subtype, midpoint width, VA length, and posterior semicircular canal-posterior fossa distance. Two neuroradiologists independently evaluated all images. Diagnostic performance for six clinically motivated tasks was assessed by AUC with leave-one-patient-out cross-validation (LOPOCV); associations with pure-tone average (PTA) were evaluated by multivariable linear regression with cluster-robust standard errors.

RESULTS

Interobserver agreement was excellent (ICC, 0.84-0.91). VA visibility grading identified the hypoplastic endotype with an AUC of 0.860 (LOPOCV, 0.812); combined VA morphology and midpoint width distinguished the degenerated endotype with an AUC of 0.784 (LOPOCV, 0.736). Multivariable regression identified ATVA as an independent PTA predictor (β = 0.238, p = 0.023).

CONCLUSIONS

PCCT-derived VA morphometric parameters enabled MD endotype identification despite clinical heterogeneity and were associated with hearing loss severity, supporting their potential role as imaging biomarkers for MD management.