American Journal of Neuroradiology, Vol 17, Issue 9 1707-1716, Copyright © 1996 by American Society of Neuroradiology
ARTICLES |
Submillimeter-resolution MR of the endolymphatic sac in healthy subjects and patients with Meniere disease
P Schmalbrock, T Dailiana, DW Chakeres, MC Oehler, DB Welling, PM Williams and L Roth
Department of Radiology, Ohio State University, Columbus, OH 43210, USA.
PURPOSE: To evaluate the utility of submillimeter resolution MR imaging for direct depiction of functional soft-tissue components of the intraosseous endolymphatic duct and sac in healthy subjects and in patients with Meniere disease. METHODS: Axial MR images were acquired of 14 patients with Meniere disease and 14 healthy volunteers at 1.5 T with a short-echo-time steady-state 3-D gradient-echo sequence. Seven volunteers and eight patients were also studied with a T1-weighted 3-D spoiled gradient-echo sequence. T1/T2 relaxation times were estimated from studies with multiple flip angles. RESULTS: Independent of the acquisition method, intraosseous endolymphatic ducts and sacs were seen unambiguously in the ears of 20 of 21 healthy subjects but in only four of 12 asymptomatic and two of 10 symptomatic ears of patients with Meniere disease. Other labyrinthine structures were well depicted in all subjects. Furthermore, shorter relaxation times were measured for the contents of the vestibular aqueduct than for other labyrinthine structures. CONCLUSION: In our high-resolution study, the intraosseous portions of the endolymphatic ducts and sacs were depicted in most of the healthy subjects. They were frequently not seen in either ear of patients with unilateral Meniere disease, presumably because of their small size.