Magnetic resonance imaging of the temporal bone in patients with Ménière's disease.

Ménière's disease (MD) is still controversial in several aspects. The vestibular aqueduct, the osseous channel that carries the endolymphatic duct and sac, has previously been studied by tomography and computed tomography, with shortening and narrowing of this structure observed. These findings are apparently correlated to the development of the endolymphatic hydrops present in MD and related to its episodic symptoms. In studying the endolymphatic duct, the key structure in the pathology of this disease, magnetic resonance imaging (MRI) studies of the temporal bone were performed in 12 patients with unilateral MD and in 9 bilateral cases; the results were compared with images obtained from 30 normal ears. The endolymphatic duct appeared to be statistically less visible in MD patients, with no difference between symptomatic and asymptomatic ears in the presence of unilateral disease. No relationship was found between visualization of the endolymphatic duct and time of evolution or response to clinical treatment in these cases. The distance from the posterior semicircular canal to the posterior temporal border was found to be bilaterally reduced in MD. The authors conclude that although the demonstration of endolymphatic hydrops "in vivo" is not yet possible by MRI, some features can be observed that can support a clinical hypothesis of MD.