Visualization of inner ear disorders with MRI in vivo: from animal models to human application.
CONCLUSIONS
The inner ear membranous permeability and leakiness and endolymphatic hydrops can be visualized using gadolinium-enhanced MRI in both rodents and man. Intratympanic administration of contrast agent gives greater perilymphatic loading of gadolinium.


OBJECTIVE
Visualization of different types of inner ear dysfunction in MRI with intravenous or intratympanic administration of contrast agent.


METHODS
In the animal study, gadolinium was administered intravenously or intratympanically and imaged with 4.7 T MRI. In man, gadolinium was delivered intratympanically and studied with 1.5 T or 3 T MRI.


RESULTS
In the animals, intravenous delivery of gadolinium demonstrated uptake in the perilymph of normal inner ears. The cochlear modiolus appeared to be a critical site for the secretion of perilymph and the location of fluid communication between the perilymphatic scalae. Intense noise exposure and immune reaction caused cochlear injury and accelerated gadolinium passage through the blood-perilymph and blood-endolymph barriers. In man, perilymphatic uptake of gadolinium was only observed in the impaired inner ear when administered intravenously. However, the signal-to-noise ratio of images was improved when gadolinium was delivered intratympanically. MRI demonstrated endolymphatic hydrops in both animal models and patients with Meniere's disease.
Zou
Jing
J
Department of Otolaryngology, University of Tampere Medical School, Tampere, Finland. Jing.Zou@uta.fi
Poe
Dennis
D
Bjelke
Bolje
B
Pyykko
Ilmari
I
D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage / Q000493:pharmacokinetics; D004195:Disease Models, Animal; D019786:Gadolinium DTPA / Q000008:administration & dosage / Q000493:pharmacokinetics; D006801:Humans; D007759:Labyrinth Diseases / Q000150:complications / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging
D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA