[MR imaging for evaluation of severe facial nerve damage in patients with facial nerve palsy].

Purpose: To evaluate the usefulness of MR imaging for the detection of severe facial nerve damage in patients with facial nerve palsy.
Materials and Methods: We retrospectively reviewed 26 consecutive patients with facial nerve palsy (13 non-responders and 13 responders). T1-weighted, T2-weighted, and postcontrast T1-weighted images were obtained in all patients. FLAIR images were also obtained in 3 non-responders.
Results: The geniculate ganglion, labyrinthine segment, and tympanic segment or mastoid segment showed high signal intensity on T2-weighted images in 9 of 13 non-responders, whereas high signal intensity of the nerve was only seen in 1 of 13 responders. FLAIR imaging revealed high signal intensity lesions of the distal intrameatal segment in 2 non-responders. Contrast enhancement of the facial nerve showed a similar pattern in non-responders and responders. High signal intensity lesions on T2-weighted or FLAIR images showed enhancement on postcontrast T1-weighted images.
Conclusion: These results suggest that a high signal intensity area on T2-weighted images is a marker of severe facial nerve damage. FLAIR imaging is useful for identification of T2-prolongation in the distal intrameatal segment.