Visualization of inner ear disorders with MRI in vivo: from animalmodels to human application

摘要

Conclusion: The inner ear membranous permeability and leakiness and endolymphatic hydrops can be visualized usinggadolinium-enhanced MRI in both rodents and man. Intratympanic administration of contrast agent gives greaterperilymphatic loading of gadolinium. Objectives: Visualization of different types of inner ear dysfunction in MRI withintravenous or intratympanic administration of contrast agent. Materials and methods: In the animal study, gadolinium wasadministered intravenously or intratympanically and imaged with 4.7 T MRI. In man, gadolinium was deliveredintratympanically and studied with 1.5 T or 3 T MRI. Results: In the animals, intravenous delivery of gadoliniumdemonstrated uptake in the perilymph of normal inner ears. The cochlear modiolus appeared to be a critical site for thesecretion of perilymph and the location of fluid communication between the perilymphatic scalae. Intense noise exposureand 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 whenadministered intravenously. However, the signal-to-noise ratio of images was improved when gadolinium was deliveredintratympanically. MRI demonstrated endolymphatic hydrops in both animal models and patients with Meniere's disease.