High-Resolution 3D MR Imaging of the Trochlear Nerve

Concordant visibility of the trochlear nerves on conventional- and high-resolution 3D-bTFE images in a 34-year-old man. A, Conventional image with a fusion of different right and left levels shows curvilinear nonbranching structures (arrows) with “probable” visibility, coursing in an anterolateral direction toward the ipsilateral tentorium. B, Reformatted high-resolution image clearly shows the trochlear nerves bilaterally (arrows) from the root exit points with “definite” visibility.

False-positive case of the trochlear nerve on a conventional-resolution 3D-bTFE image in a 47-year-old man. A, Conventional image shows the root exit point and its cisternal course of the left trochlear nerve (arrows) with “definite” visibility. B, Reformatted high-resolution image clearly separates the left trochlear nerve (arrows) from the vessel (arrowheads), which is misinterpreted as the trochlear nerve in A.