In vivo anatomical analysis of arterial contact with trigeminal nerve: detection with three-dimensional spoiled grass imaging

The purpose of this study was to review the normal in vivo neurovascular re lationship between the trigeminal nerve and surrounding arteries without th e use of volunteers. 290 nerves in 145 cases were reviewed during a 1-year period. Axial source images and multiplanar reconstructed (MPR) images were used to determine the neurovascular contact and direction of contact. Mult iplanar volume reformation (MPVR) was used to identify the contact vessels and to demonstrate the relationship between the nerve and arteries. Vascula r contact was found in 29% of the 290 nerves (83 nerves). The arteries invo lved were the superior cerebellar artery (SCA) or the anterior inferior cer ebellar artery (AICA). Vascular contact with two arteries was found in 3%. Of the 286 asymptomatic nerves, the nerve was located between the two vesse ls in 3% and compression was seen in 1%. Three points of vascular contact b y the two arteries were identified in one asymptomatic nerve. The direction of contact between the SCA and the nerve was superior (38%), superomedial (32%) or medial (15%) in most cases. The direction of contact between the A ICA and the nerve was inferior, inferolateral or lateral in all cases. Vasc ular contact at the root entry zone (REZ) was noted in 90%. Four nerves wer e affected by trigeminal neuralgia, one of which touched an artery and two were compressed. It was concluded that arterial contact call be assessed wi thout difficulty but evaluation of vascular compression is not easy.