q. ding

To explore the efficacy and optimal modality of three-dimensional (3D) MRI sequences in the preoperative detection of neurovascular compressions (NVCs) in patients with trigeminal neuralgia (TN).

Forty-nine cases of typical unilateral TN had undergone 3D time-of-flight magnetic resonance angiography (3D-TOF MRA), 3D fast imaging employing steady-state acquisition (3D-FIESTA), and contrast-enhanced 3D spoiled gradient-recalled sequence (3D-SPGR) on a 3 Tesla MR scanner. Neurovascular relationships (including neurovascular contact and position and the nature of the offending vessels) on MR images were reviewed by a neuroradiologist who was unaware of the clinical findings. Subsequently, microvascular decompression (MVD) surgery was performed on all patients. Comparison was made between the imaging results and surgical findings.

MVD verified NVC in 48 (98%) symptomatic nerves, while 3D-TOF MRA, 3D-FIESTA, and 3D-SPGR revealed NVC in 38 (78%), 48 (98%), and 47 (96%) cases, respectively. Agreement between the position of NVC, as defined by 3D-FIESTA (κ = 0.86) or 3D-SPGR (κ = 0.83) and surgical findings, was excellent. Moreover, excellent agreement was confirmed between the nature of compressing vessels as defined by 3D-FIESTA in combination with 3D-TOF MRA (κ = 0.95) or contrast-enhanced 3D-SPGR in combination with 3D-TOF MRA (κ = 0.92) and surgical findings.

NVCs were visualized with good sensitivity and specificity with 3D MRI sequences in TN. We propose that 3D-FIESTA combined with 3D-TOF MRA is a safe, convenient, and efficacious MRI sequence for revealing NVCs and is crucial for the preoperative diagnosis and surgical planning of MVD.