Magnetic resonance imaging of intratemporal facial nerve lesions in the animal model.

The facial nerve is often injured in head trauma. Computed tomography (CT) is the diagnostic study most frequently used to evaluate temporal bone fractures, but it does not demonstrate all soft tissues well. Recently, magnetic resonance imaging (MRI) has been used to evaluate certain soft tissues, including cranial nerves. Experience with MRI evaluation of temporal bone trauma is limited and consists primarily of anecdotal reports. This study assesses the accuracy of MRI in evaluating experimentally induced acute intratemporal facial nerve lesions. The tympanic segments of the right facial nerve in nine rabbits were contused, and MRI scans were performed without and with gadolinium-diethyl-triamine-pentaacetic acid (Gd-DTPA) at varying intervals after surgery. MRI with Gd-DTPA accurately identified the lesion site in eight of nine subjects. Gd-DTPA-enhanced MRI appears to be useful in the evaluation of traumatic facial nerve injuries.