MR Imaging of the Intratemporal Facial Nerve Using Surface Coils

Abstract

MR images of the intratemporal portion of the facial nerve were obtained with surface coils using a 0.3-T permanent magnet whole-body imaging system. Various 20FT spin-echo pulse sequences were used to produce 5-mm thick sections with 0.5-mm pixels on a 512 × 512 acquisition matrix. The MR images from normal volunteers were correlated with cryosection specimens of three fresh human cadavers. The seventh nerve was followed in the internal auditory and fallopian canal and through temporal bone to the stylomastoid foramen. The entire labyrinthine, tympanic, and mastoid portions, as well as the geniculate ganglion, could be shown with appropriate scan planes. MR produces excellent images of the facial nerve with high-contrast resolution. Unlike CT, no beam-hardening artifact from the temporal bone is apparent. MR should be a sensitive study for the evaluation of intratemporal facial nerve disease.