High-resolution MR imaging of the inner ear

Symptoms in Meniere's disease are characterized by hydrops of the endolymphatic system wit recurrent rupture of the membranous labyrinth. The primary cause of increased endolymphatic volume appears to be an imbalance between secretion and resorption of the endolymph which may be due to an obstruction of the membranous endolymphatic duct and sac, located in the vestibular aquaduct. Membranous endolymphatic duct and sac are not expected to be visualized using conventional tomography and high-resolution computed tomography, whereas these are identified with high resolution MRI (HR-MRI). By HR-MRI, the authors proposed to demonstrate morphological alternation in 12 patients with Meniere's disease, this group was compared with a group of 20 healthy subjects. The degree of visualization on HR-MRI of the membranous endolymphatic duct and sac running through the vestibular aqueduct in the bony canal was assessed. There was a distinct decrease in visualization of the membranous endolymphatic duct and sac in the Meniere's group. The results confirm the value of HR-MRI to identify an anatomical abnormality, which is directly correlated with the lesion in cases of unilateral Meniere's disease. (author). 23 refs.; 4 figs.; 1 tab