title: [Magnetic resonance imaging manifestations of radiation injury in brain stem and cervical spinal cord of nasopharyngeal carcinoma patients after radiotherapy].
abstract: OBJECTIVE
  It is very important to diagnose the radiation injury in brain stem and cervical spinal cord of patients with nasopharyngeal carcinoma (NPC) after radiotherapy. Magnetic resonance imaging (MRI) manifestations of radiation encephalopathy have been widely reported, while those of radiation injury in brain stem and cervical spinal cord have been seldom reported. This study was to analyze the MRI characteristics of radiation injury in brain stem and cervical spinal cord of patients with NPC after radiotherapy.
  
  
  METHODS
  MRI was performed in 60 NPC patients 6 months to 5 years after radiotherapy. The imaging sequences included T(1)-weighted image (T(1)WI), T2-weighted image (T(2)WI), fluid attenuated inversion recovery (FLAIR). All patients received T(1)WI contrast-enhanced scanning.
  
  
  RESULTS
  Of the 60 patients, 6 had lesions in cervical spinal cord, 54 had lesions in brain stem. Of the 54 cases of radiation injury in brain stem, most lesions located in pons (20 cases), basis pons and medulla oblongata (26 cases), others located in mesencephalon (3 cases), medulla oblongata (5 cases). All lesions showed hypo- or iso-intense signal on T(1)WI, and hyper-intense signal on T(2)WI. After contrast-enhanced scanning, 11 cases (18.3%) had no enhancement; 49 (81.7%) markedly enhanced with 21 cases (42.9%) of homogenous patchy enhancement, and 28 cases (57.1%) of hetergenerous ringed and patchy enhancement.
  
  
  CONCLUSIONS
  MRI shows clearly the radiation injury in brain stem and cervical spinal cord of NPC patients after radiotherapy.
authors.affiliation: Department of Radiology, The Second Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, 510120, P.R.China. gzflair@21cn.com
authors.forename: Ting
authors.initials: T
authors.lastname: Song
authors.forename: Bi-Ling
authors.initials: BL
authors.lastname: Liang
authors.forename: Sui-Qiao
authors.initials: SQ
authors.lastname: Huang
authors.forename: Bang-Kun
authors.initials: BK
authors.lastname: Xie
authors.forename: Zhong-Xiang
authors.initials: ZX
authors.lastname: Ding
authors.forename: Jun
authors.initials: J
authors.lastname: Shen
mesh_terms: D000328:Adult; D000368:Aged; D001933:Brain Stem / Q000473:pathology / Q000528:radiation effects*; D002574:Cervical Vertebrae; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy*; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000175:diagnosis*; D011878:Radiotherapy / Q000009:adverse effects*; D012189:Retrospective Studies; D013116:Spinal Cord / Q000473:pathology / Q000528:radiation effects*