title: MRI signal changes in the skull base bone after endoscopic nasopharyngectomy for recurrent NPC: a serial study of 9 patients.
abstract: OBJECTIVE
  This study was focused on the serial changes in magnetic resonance images (MRI) of the skull-base bone that occur after endoscopic nasopharyngectomy in patients with local recurrent nasopharyngeal carcinoma (rNPC).
  
  
  METHODS
  Nine patients with histologically proven rNPC were enrolled in this study. Two experienced radiologists independently reviewed all presurgical and postsurgical MR images for each patient.
  
  
  RESULTS
  At 36 sites on the skull base, the MRI signal underwent a change after surgery, which took the form of a heterogeneous pattern of hypointense regions with moderate contrast enhancement on T1WI. The onset of changes ranged between 2 weeks and 3 months after surgery. For 21 of the sites, the changes subsided over the course of follow-up, while in 6 they remained stable. At 9 sites, the alteration MRI signal became more pronounced with time. Changes were more common on the homolateral side of the skull base with respect to the recurrent tumor (P<0.05). The skull-base bone adjacent to the resection boundary had a higher incidence of signal change than nonadjacent areas (P<0.05).
  
  
  CONCLUSIONS
  MRI changes in the skull base bone, having a number of distinguishing characteristics, appear to be a common sequel to endoscopic nasopharyngectomy for rNPC.
authors.affiliation: State Key Laboratory of Oncology in Southern China, Guangzhou, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: De-ling
authors.initials: DL
authors.lastname: Wang
authors.forename: Xue-wen
authors.initials: XW
authors.lastname: Liu
authors.forename: Ming-yuan
authors.initials: MY
authors.lastname: Chen
authors.forename: Yun-xian
authors.initials: YX
authors.lastname: Mo
authors.forename: Zhi-jun
authors.initials: ZJ
authors.lastname: Geng
authors.forename: Chuan-miao
authors.initials: CM
authors.lastname: Xie
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D004724:Endoscopy / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000473:pathology* / Q000601:surgery*; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000601:surgery*; D010611:Pharyngectomy / Q000379:methods*; D019292:Skull Base Neoplasms / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome