Role of Fused Three-Dimensional Time-of-Flight Magnetic Resonance Angiography and 3-Dimensional T2-Weighted Imaging Sequences in Neurovascular Compression.

Abstract

To evaluate role of fused 3-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) and 3-dimensional constructive interference in steady state (3D-CISS) in neurovascular compression in trigeminal neuralgia (TN) and hemifacial spasm (HFS). A prospective study was conducted on 30 patients (mean age 47.20 ± 11.69 years), 17 (56.7%) male and 13 (43.3%) female, with TN and HFS. 3D-TOF-MRA and 3D-CISS sequences of the cerebellopontine angle were performed, as well as postprocessing with fusion of the images. Two independent readers assessed the degree of neurovascular conflict. The images were evaluated for site, signal, and degree of nerve compression and the offending vessel. The kappa test for interobserver agreement was done. The interobserver agreement of both readers was excellent for degree of compression (k = 0.70, 95% confidence interval [CI] 0.49-0.92, r = 0.856, P = 0.001), excellent for the side affected (k = 1.0, 95% CI = 1.0-1.0, r = 1.000, P = 0.001), excellent for the offending vessel (k = 0.85, 95% CI = 0.66-1.0, P = < 0.001), and excellent for the position of the offending vessel (k = 0.685, 95% CI = 0.489-0.882, r = 0.863, P ≤ 0.001). There was no significant correlation between the degree of compression and signal intensity. Fused 3D-TOF-MRA and 3D-CISS images are a reliable, noninvasive tool for the evaluation of offending vessel and degree of affection in patients with neurovascular compression. MRA-CISS can be used for evaluation and treatment planning of neurovascular compression in TN and HFS.