title: Diffusion-weighted magnetic resonance neurography for parapharyngeal schwannomas: preoperative determination of the originating nerves.
abstract: OBJECTIVE
  The aim of this study was to assess the feasibility of diffusion-weighted (DW) magnetic resonance neurography (MRN) for determining the originating nerve of parapharyngeal schwannomas preoperatively.
  
  
  METHODS
  Six patients who underwent DW-MRN preoperatively for a parapharyngeal schwannoma were studied. Prediction of the originating nerve was performed. With the conventional method, a tumor showing "separation" between the internal jugular vein and carotid artery was determined to originate from the vagus nerve, with "no separation" from the sympathetic chain. With DW-MRN, the relationships between the vagus nerve and sympathetic chain to the tumor were characterized as "connected" or "dislocated." A nerve connected to the tumor was determined as the origin.
  
  
  RESULTS
  Surgeries revealed that the origins included 1 vagus nerve and 5 sympathetic chains. Using a conventional method, all 6 cases were diagnosed correctly, whereas DW-MRN successfully predicted only 4 cases with a sympathetic chain origin.
  
  
  CONCLUSIONS
  The DW-MRN is a feasible approach for determining an originating nerve.
authors.affiliation: From the *Department of Radiology, Tokyo Medical and Dental University Hospital; †Department of Radiology, Omori Red Cross Hospital; and Departments of ‡Otolaryngology, §Head & Neck Surgery, and ∥Human Pathology, Tokyo Medical and Dental University Hospital, Tokyo, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kitazume
authors.forename: Isamu
authors.initials: I
authors.lastname: Ohashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Katayama
authors.forename: Atsunobu
authors.initials: A
authors.lastname: Tsunoda
authors.forename: Seiji
authors.initials: S
authors.lastname: Kishimoto
authors.forename: Mariko
authors.initials: M
authors.lastname: Negi
mesh_terms: D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D005240:Feasibility Studies; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000175:diagnosis*; D010525:Peripheral Nerves / Q000033:anatomy & histology*; D010614:Pharynx; D011300:Preoperative Care; D012189:Retrospective Studies; D055815:Young Adult