Validation by magnetic resonance imaging of tympanometry for diagnosing middle ear effusion

This study was performed to correlate tympanometric gradient with measureme nts of effusion quantity by use of MRI during an experimental otitis media with effusion episode in 4 cynomolgus monkeys. Paired results for the inten sity values of the T-2-weighted MRI scans and the tympanometric width measu red in the right ear of all animals before and on days 15, 21, 29, and 36 a fter botulinum paralysis of the tensor veli palatini muscle were analyzed. All right ears showed a progressive increase during the study period in the signal intensity of the MRI. Whereas the average middle ear pressures decr eased, the average tympanometric widths demonstrated a progressive increase during the course of the experimental otitis media with effusion. Signific ant correlations between tympanometric width and MRI measures of effusion w ere documented, confirming the high predictive value of the tympanometric w idth for diagnosing the presence and quantity of middle ear effusion.