MRI study on etiologic diagnosis of idiopathic trigeminal neuralgia

Aim:To study MRI features of trigeminal neuralgia,and to evaluate MRI for the diagnosis of trigeminal neuralgia. Methods:Conventional MRI and 3D-FISP sequence were performed in 114 patients with trigeminal neuralgia.The anatomic changes of bilateral trigeminal nerves were observed and the distance from the trigeminal nerves to surrounding vessels were measured.Results:(1)The 3D-FISP sequence demonstrated vessels indentation in 21 cases and contiguity in 61 cases on the symptomatic side(positivity rate 71.9%),while on the unsymptomatic side it was in 9 cases(positivity rate 7.9%).The significance was showed by the chisquare test(P0.005);(2)The conventional MRI demonstrated that positive sign was 50.9% on the symptomatic side and 6.1% on the unsymptomatic side.Conclusion:MRI 3D-FISP sequence is a very useful technique in diagnosis of trigeminal neuralgia;The major cause of trigeminal neuralgia is the close relatinship between trigeminal nerve and it's surrounding vessels.