A single-blinded pilot study assessing neurovascular contact by using high-resolution MR imaging in patients with trigeminal neuralgia

Abstract

Objective To assess the feasibility and utility of high-resolution three-dimensional magnetic resonance angiography (3D MRA) and contrast-enhanced 3D spoiled gradient-recalled imaging (3D SPGRI) for the purpose of visualization of neurovascular contact in trigeminal neuralgia (TN) patients. Methods Forty-five patients (25 males, 20 females; age range, 23–82 years; and mean age, 55.67 ± 18.23 years) with unilateral typical TN and 36 control subjects (21 males, 15 females; age range, 25–85 years; mean age, 57.53 ± 19.25 years) underwent high-resolution 3D MRA and contrast-enhanced 3D SPGRI assessment. The images were reviewed by two experienced neuroradiologists who were blinded to the clinical details. The imaging results were compared with the operative findings in all the patients; additionally, the degree of neurovascular contact was compared between the two groups based on MR imaging. Results In 45 patients with unilateral typical TN, the use of 3D MRA in conjunction with the contrast-enhanced 3D SPGRI identified neurovascular contact in 40 of the 42 symptomatic nerves; the contact was verified surgically. Based on the surgical findings, the sensitivity and specificity of MR imaging were 95.20% and 100%, respectively. Based on MRI, the compressing vessel (artery, vein) was correctly identified in 32 of the 39 cases verified by microvascular decompression. There was good agreement ( K = 0.77; 95% confidence interval, 0.54–0.99) between the position (medial, lateral, superior, and inferior) of the compressing vessel relative to the trigeminal nerve as defined by MR imaging and the surgical findings. The rates of vascular contact with the trigeminal nerve as observed on MRI were 31.94%, 48.89%, and 88.9% in the control subjects, asymptomatic, and symptomatic side of patients, respectively. Conclusion The combined use of high-resolution 3D MRA and contrast-enhanced 3D SPGRI is an extremely sensitive and specific technique for demonstrating vascular contact with the trigeminal nerve in TN patients.