Investigation of MRI Findings in Bell's Palsy Correlated with Operative Results

Objective To investigate the MR findings and its diagnostic value in bell's palsy.Materials and Methods MRI findings of 14 patients with bell's palsy were analyzed retrospectively.8 cases were compared with the operative findings.Results intrameatal and labyrinthine segments of the normal facial nerves were not enhanced,whereas enhancement of distal intrameatal and labyrinthine segments were respectively found in 71%(10/14) and 93%(13/14) of affected facial nerves.The geniculate ganglions were enhanced in 93%(13/14) affected facial nerves versus 29%(4/14)in normal facial nerves.The tympanic segments were enhanced in 43%(6/14) affected facial nerves versus 1%(1/14)in normal facial nerves.The mastoid segments were enhanced in 79%(11/14) affected facial nerves versus 71%(10/14)in normal facial nerves.MRI enhanced findings were corresponded with edema of the paralytic facial nerves in operations.Conclusion Enhancement of distal intrameatal and labyrinthine segments is specific and sensitive in the diagnosis of Bell's palsy,while,the enhancement of mastoid segments is nonspecific.Enhanced MRI can demonstrate the extent of lesion objectively,which may be helpful in the diagnosis and differential diagnosis of Bell's palsy and provide important information for facial nerve decompression.