The use of magnetic resonance imaging with high-resolution CT in the evaluation of facial paralysis.

Magnetic resonance imaging (MRI) has been widely used in the evaluation of suspected acoustic neuroma, but has not received the same attention with respect to facial paralysis. High-resolution computed tomography (HRCT) has been the radiologic test of choice to evaluate the facial nerve. The necessary HRCT projections, slices, and enhancement techniques to visualize each segment have been outlined. We have developed a radiologic protocol that uses MRI in conjunction with HRCT, applying the strengths of each to evaluate the facial nerve. We have evaluated 15 patients and have found that MRI is the better study to evaluate the brain stem/cerebellopontine angle segment of the facial nerve and better evaluates bone-soft tissue interfaces. HRCT is better in the evaluation of the intratemporal segment of the facial nerve and the assessment of the anatomic perspectives of a lesion within the temporal bone. The results are discussed and case reports illustrate the efficacy of this approach.