Trigeminal Ganglion and its Divisions: Detailed Anatomic MR Imaging with Contrast-Enhanced 3D Constructive Interference in the Steady State Sequences

Sagittal nonenhanced 3D CISS image through the right side of the Meckel cave in a 58-year-old woman. Sensory root (SeR) is shown from its apparent origin at the pons (P) to the entrance of the cave. Ganglion (thick white arrow) at the anterior aspect of the cave is difficult to identify, and anterior margin of the trigeminal ganglion cannot be distinguished from the dural wall (arrowhead) of the cave. Only the superior lip of the ganglion (thin white arrow) is well defined. One smaller and one larger sensory rootlet (long black arrows) arise from the sinus ganglii (short black arrow) and course in the trigeminal cistern (TC). Maxillary nerve is not depicted at the inferior border of the cavernous sinus. CA = carotid artery, PC = prepontine cistern, TE = cerebellar tentorium, TL = temporal lobe.

Enhanced 3D CISS images through the right side of the Meckel cave in a 62-year-old woman. TL = temporal lobe.

A, Sagittal image shows a small portion of the sensory root (SeR) at its entry into the cave. Trigeminal ganglion (thick white arrow) and its lips (thin white arrows) are shown at the anterior end of the cave. Anterior margin of the ganglion is clearly differentiated from the dural wall (white arrowhead) of the cave. Two sensory rootlets (long black arrows) emerge from the sinus ganglii (short black arrow) and pass through the trigeminal cistern. Maxillary nerve (V2) courses along the inferior wall of the cavernous sinus, surrounded by enhancing venous channels (black arrowhead). CA = carotid artery, FR = foramen rotundum, PC = prepontine cistern, TE = cerebellar tentorium.

B, Coronal image shows the cave bilaterally. Trigeminal ganglion (thick white arrows) lies along the anteroinferior border of the cave. Less-enhancing dura (arrowheads) is clearly differentiated from the ganglion. Multiple, small sensory rootlets (thin white arrows) are seen in the trigeminal cistern (TC). Mandibular nerve (V3) is partly shown on the right side in the foramen ovale (FO).

Sagittal enhanced 3D CISS image through the right side of the Meckel cave in a 54-year-old man. Sensory root (SeR) is displayed from its apparent origin at the pons (P) to the entrance of the cave. Trigeminal ganglion (thick white arrow) is at the anteroinferior border of the cave. Anterior margin of the enhancing ganglion is clearly distinguished from the less-enhancing dura (white arrowhead) of the cave. Lips of the ganglion (thin white arrows) define the sinus ganglii (short black arrow) from which small sensory rootlets (long black arrows) arise. Maxillary nerve (V2) is depicted along the inferior border of the cavernous sinus, surrounded by venous channels (black arrowhead) en route to the foramen rotundum (FR). CA = carotid artery, MoR = motor root of the trigeminal nerve at its point of exit, PC = prepontine cistern, TE = cerebellar tentorium, TL = temporal lobe.