3-T imaging of the cranial nerves using three-dimensional reversed FISP with diffusion-weighted MR sequence.

PURPOSE To depict the normal anatomy of cranial nerves in detail and define the exact relationships between cranial nerves and adjacent structures with three-dimensional reversed fast imaging with steady-state precession (FISP) (3D-PSIF) with diffusion-weighted MR sequence. MATERIALS AND METHODS 3D-PSIF with diffusion-weighted MR sequence was performed and axial images were obtained in 22 healthy volunteers. Postprocessing techniques were used to generate images of cranial nerves, and the images acquired were compared with anatomical sections and textbook diagrams. RESULTS In all subjects, 3D-PISF sequence could produce homogeneous images and high contrast between the cranial nerves and other solid structures. The intracranial portions of all cranial nerves except the olfactory nerve were identified; the extracranial portions of nerves II-XII, except the nerves within the cavernous sinuses, were identified in all subjects bilaterally. CONCLUSION The 3D-PSIF with diffusion-weighted sequence can characterize the normal MR appearance of cranial nerves and its branches. The ability to define the nerves may provide greater sensitivity and specificity in detecting abnormalities of craniofacial structure.