title: Visualization of Cranial Nerves Using High-Definition Fiber Tractography.
abstract: Recent studies have demonstrated diffusion tensor imaging tractography of cranial nerves (CNs). Spatial and angular resolution, however, is limited with this modality. A substantial improvement in image resolution can be achieved with high-angle diffusion magnetic resonance imaging and atlas-based fiber tracking to provide detailed trajectories of CNs.
  
  
  
  To use high-definition fiber tractography to identify CNs in healthy subjects and patients with brain tumors.
  
  
  
  Five neurologically healthy adults and 3 patients with brain tumors were scanned with diffusion spectrum imaging that allowed high-angular-resolution fiber tracking. In addition, a 488-subject diffusion magnetic resonance imaging template constructed from the Human Connectome Project data was used to conduct atlas space fiber tracking of CNs.
  
  
  
  The cisternal portions of most CNs were tracked and visualized in each healthy subject and in atlas fiber tracking. The entire optic radiation, medial longitudinal fasciculus, spinal trigeminal nucleus/tract, petroclival portion of the abducens nerve, and intrabrainstem portion of the facial nerve from the root exit zone to the adjacent abducens nucleus were identified. This suggested that the high-angular-resolution fiber tracking was able to distinguish the facial nerve from the vestibulocochlear nerve complex. The tractography clearly visualized CNs displaced by brain tumors. These tractography findings were confirmed intraoperatively.
  
  
  
  Using high-angular-resolution fiber tracking and atlas-based fiber tracking, we were able to identify all CNs in unprecedented detail. This implies its potential in localization of CNs during surgical planning.
  
  
  
  CN, cranial nerveDSI, diffusion spectrum imagingDTI, diffusion tensor imagingHCP, Human Connectome ProjectHDFT, high-definition fiber tractographyMLF, medial longitudinal fasciculusODF, orientation distribution functionROI, region of interest.
authors.affiliation: *Department of Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania; ‡Department of Psychology, Carnegie Mellon University, Pittsburgh, Pennsylvania; §Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Masanori
authors.initials: M
authors.lastname: Yoshino
authors.forename: Kumar
authors.initials: K
authors.lastname: Abhinav
authors.forename: Fang-Cheng
authors.initials: FC
authors.lastname: Yeh
authors.forename: Sandip
authors.initials: S
authors.lastname: Panesar
authors.forename: David
authors.initials: D
authors.lastname: Fernandes
authors.forename: Sudhir
authors.initials: S
authors.lastname: Pathak
authors.forename: Paul A
authors.initials: PA
authors.lastname: Gardner
authors.forename: Juan C
authors.initials: JC
authors.lastname: Fernandez-Miranda
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D003391:Cranial Nerves / Q000000981:diagnostic imaging*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male