Otitis media (OM) is the most common pediatric illness requiring physicians' office visits. The use of animal models to study OM is well established and a large amount of knowledge on its pathogenesis and treatment has been amassed. Current models utilize biochemical, bacteriologic, and histologic assays to measure the inflammatory response of the host. These models are either in vitro or ex vivo and lack the ability to assess dynamic real-time physiologic changes. Recently, an in vivo model of oM using magnetic resonance imaging (MRI) enhanced by a contrast agent was described. This technique is capable of resolving thin structures such as the middle-ear (ME) mucosa as validated by a histologic comparison. In addition, acute and chronic OM can be differentiated based on characteristic washout rates of the contrast agent. This methodology would offer unique opportunity to investigate the ME mucosa in vivo as it relates to vascular permeability. This model allows longitudinal data acquisition which represents current events rather than cumulation of past events. This investigation will use the chinchilla OM models to refine the sensitivity and specificity of the imaging methodology. The effects of acute and chronic inflammation on the washout rate of the contrast agent will be documented. Additionally, the effects of major drug groups on the inflammatory process will be assessed using interventional models. Results from the MRI technique will be correlated to other methods of vascular permeability and extension of the method to other species such as the domestic cat will be initiated. Although this enhanced imaging method is not yet approved for humans, further investigation may result in future application of this technique.
NIH ExPorter
NIH ExPorter