State of the Art: 3T Imaging of the Membranous Labyrinth

J.I. Lane,R.J. Witte,K. Johnson,M.A. Bernstein,J. Morris,B. Bolster

doi:10.3174/ajnr.a1036

J.I. Lane, R.J. Witte + Show 4 more

Open Access

https://doi.org/10.3174/ajnr.a1036

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Abstract

This article reviews the anatomy of the membranous labyrinth and demonstrates the ability of high-resolution MR imaging at 3T to visualize the neurosensory epithelium by using the latest fast spin-echo techniques.

Highlights

Visualization of the membranous structures of the inner ear has been limited to the detection of normal fluid signal intensity within the bony labyrinth on 1.5T or 3T MR imaging
Some of this artifact can be reduced by summing successive phase-cycled acquisitions reconstructed with a maximum intensity projection as with constructive interference in the steady state (CISS), these artifacts again become problematic with the very small FOVs required for temporal bone imaging and obscure portions of the membranous labyrinth
Our results indicate that it is possible to visualize portions of the membranous labyrinth that may be affected by vestibulocochlear pathology

Summary

Introduction

Visualization of the membranous structures of the inner ear has been limited to the detection of normal fluid signal intensity within the bony labyrinth on 1.5T or 3T MR imaging. The ability to directly visualize the endolymphatic vesicles of the inner ear might permit the development of imaging criteria in the diagnosis and treatment of labyrinthine disease. 3D sequences to include constructive interference in the steady state (CISS) or fast spin-echo (FSE) techniques provide excellent depiction of the nerves within the internal auditory canal as well as the fluid within the labyrinth, but attempts to image organs of the membranous labyrinth have been compromised by susceptibility banding artifact in the case of gradient-echo acquisitions and image blurring inherent to fast spin-echo (FSE) sequences.. We review the anatomy of the inner ear and describe the utility of 3D variable flip-angle FSE (3D VFA FSE) technique in demonstrating some of the more prominent neurosensory components of the membranous labyrinth at 3T 3D sequences to include constructive interference in the steady state (CISS) or fast spin-echo (FSE) techniques provide excellent depiction of the nerves within the internal auditory canal as well as the fluid within the labyrinth, but attempts to image organs of the membranous labyrinth have been compromised by susceptibility banding artifact in the case of gradient-echo acquisitions and image blurring inherent to fast spin-echo (FSE) sequences. In this article, we review the anatomy of the inner ear and describe the utility of 3D variable flip-angle FSE (3D VFA FSE) technique in demonstrating some of the more prominent neurosensory components of the membranous labyrinth at 3T

Discussion

Conclusion