To investigate the application value of a novel image fusion method based on T2-weighted 3D fast spin echo with fat suppression (T2-MX3D-FS) and three dimensional time of flight magnetic resonance angiography (3D-TOF-MRA) sequences from 5.0 T ultra-high field magnetic resonance imaging in identifying the responsible vessels of primary trigeminal neuralgia (PTN), so as to provide more accurate imaging diagnostic evidence for the clinical confirmation of neurovascular compression (NVC).

A retrospective analysis was performed on the clinical and imaging data of 26 patients who were diagnosed with PTN and underwent microvascular decompression (MVD) at the First Affiliated Hospital of University of Science and Technology of China from September 2024 to August 2025. All patients underwent preoperative T2-MX3D-FS and 3D-TOF-MRA sequence scanning using a United Imaging uMR Jupiter 5.0 T superconducting MRI system, and the original images were transmitted to a post-processing workstation for image fusion analysis. Taking the responsible vessels identified during MVD as the diagnostic gold standard, we evaluated the ability of the T2-MX3D-FS sequence, 3D-TOF-MRA sequence, and the fusion sequence of the two to detect NVC, as well as their accuracy in identifying the responsible vessels.

Among the 26 patients, definite NVC was observed in 24 patients, and a total of 39 responsible vessels were identified during MVD. The accuracy of the T2-MX3D-FS sequence, 3D-TOF-MRA sequence, and fusion sequence in correctly determining the presence or absence of NVC was 84.62% (22/26), 65.38% (17/26), and 100% (26/26), respectively. The fusion sequence had the highest accuracy for NVC detection, which was higher than that of any single sequence. The difference among the three sequences was statistically significant (P=0.003 0). The accuracy of the T2-MX3D-FS sequence, 3D-TOF-MRA sequence, and fusion sequence in correctly identifying responsible vessels was 58.97% (23/39), 48.72% (19/39), and 89.74% (35/39), respectively. The qualitative accuracy of the fusion sequence for responsible vessels was significantly higher than that of the single sequences, the difference among the three sequences was statistically significant (P=0.000 2).

5.0 T ultra-high-field MRI, by virtue of its extremely high signal-to-noise ratio and spatial resolution, allows for clearer visualization of the anatomical relationship between the trigeminal nerve and surrounding microvessels. The T2-MX3D-FS and 3D-TOF-MRA sequences complement each other in displaying nerves and blood vessels. Image fusion of these two sequences significantly improves the detection rate and characterization accuracy of the responsible vessels in PTN, providing a more reliable imaging basis for the precise preoperative assessment of NVC and the formulation of individualized MVD surgical plans, demonstrating significant clinical translational value and promising application prospects.