A new methodology for evaluation of large vestibular aqueduct in CT and MRI images: finding the clinical correlation

Aim In the previous research we developed a new method to evaluate LVA/large endolymphatic sac anomaly (LESA) using CT/digital volume tomography (DVT)/MRI images. We are continuing our research, and the next goal is to find relationships between the radiological measurements and clinical course of the disease.

Methods Retrospective analysis of radiological images from 173 patients (315 ears), who were diagnosed with LVA/LESA based on CT/DVT and/or MRI images of the temporal bone, was performed in the tertiary center. The following measurements were performed on both modalities: orifice, length, external aperture measurements of vestibular aqueduct/endolymphatic duct and sac. Additional measurements like volume of extraosseus endolymphatic sac, maximal contact diameter of the dura mater and extraosseus endolymphatic sac in the axial pictures were made on MRI. The clinical course of hearing loss was defined using the patient’s history, audiometry and the patients were divided into six groups: 1. Normacusis, 2. Congenital deafness 3. Chronic progressive impairment 4. Progressive impairment from 2./3. decade of life. 5. Relapsing & progressive impairment 6. Acute deafness.

Results The logistic regression model showed that length of vestibular aqueduct and external aperture measurement in CT images are statistically significant to distinguish groups of the hearing loss. From the MRI measurements only maximal contact diameter of the dura mater and extraosseus endolymphatic sac was statistically significant to distinguish the previous explained groups.

Conclusions The new method can become a valuable tool to predict the course of hearing loss in children and adult population as well as to help to consult the patients about future treatment.

Publication History

Article published online:
12 May 2023