Severity Analysis of Neurovascular Contact in Patients with Trigeminal Neuralgia: Assessment with the Inner View of the 3D MR Cisternogram and Angiogram Fusion Imaging

Severe NVC at the affected trigeminal nerve. A, MinIP image of the source MR cisternogram (MRC). B, Operative photograph (OP-1) before decompression of the NVC at MVD surgery. C, Operative photograph (OP-2) after surgical decompression. D and E, Preoperative simulation images of the 3D MR cisternogram and angiogram fusion imaging, projected left posterolaterally (the view-position box at the right corner and indicated by a red curved arrow in A). The offending transverse pontine vein compresses the trigeminal nerve directly and the trunk of the SCA indirectly. F, Illustrative sketch of the simulation images. G and H, Inner views of the fusion MR imaging, projected posteroanteriorally along the nerve axis, viewed from inside the rootlet of the nerve at the brain stem (the view-position box at the right corner and indicated by a yellow arrowhead in A), showing the 3D anatomic relationship of the NVC. The contour of the trigeminal nerve is severely compressed by the complex of the transverse pontine vein and the trunk of the SCA. I, Illustrative sketch of the inner view. CN-V indicates the trigeminal nerve; SCA-r, rostral branch of the superior cerebellar artery; SCA-c, caudal branch of the superior cerebellar artery; SCA-t, trunk of the superior cerebellar artery; PCA, posterior cerebral artery; BA, basilar artery.