Gadolinium-enhanced magnetic resonance imaging in facial nerve lesions.

We present our 2-year experience with a contrast enhancement agent in magnetic resonance imaging (MRI) examining facial nerve pathology. Characteristics of the agent gadolinium diethylenetriamine pentaacetic acid are reviewed. The radiographic capability to differentiate pathologic vs. normal facial nerves based on enhancement and a change in signal intensity generated by the nerve is demonstrated. Experience with facial nerve disorders including Bell's palsy, facial nerve neuromas, a facial nerve graft site, postoperative facial paralysis, and traumatic facial paralysis is presented. The ability to image the facial nerve in Bell's palsy provides an entirely new means of examining this disorder, and its implications are discussed. The ability to enhance the paralyzed facial nerve in the temporal bone after posterior fossa surgery supports a previously held concept as to the pathophysiology of this problem.