title: Diffusion-weighted imaging predicts postoperative persistence in meningioma patients with peritumoural abnormalities on magnetic resonance imaging.
abstract: OBJECTIVE
  While diffusion-weighted magnetic resonance imaging (MRI) has been used to study malignant brain tumours, this modality has not been used to study MRI abnormalities surrounding meningiomas.
  
  
  METHODS
  We examined intensity and apparent diffusion coefficient (ADC) on diffusion weighted imaging (DWI) for predicting postoperative persistence of MRI abnormalities surrounding meningiomas as well as characterizing the tumours.
  
  
  RESULTS
  Of 36 meningiomas who underwent gross total resection, 27 (75%) showed hyperintensity on DWI at b=1100s/mm2. No atypical meningiomas were hypointense on DWI. Of the 26 supratentorial meningiomas, 18 (69.0%) had associated MRI abnormality. No significant correlation was seen between tumour intensity on DWI and existence of surrounding MRI abnormality. Meningothelial meningiomas showed a relatively low prevalence of MRI abnormalities surrounding tumour (30%). Of 11 patients who underwent sequential MRI, all MRI abnormalities surrounding tumour showing isointensity and high ADC on preoperative DWI disappeared after surgery (from 3 weeks to 10 months). All MRI abnormalities surrounding tumour showing hyperintensity and low ADC on preoperative DWI persisted on final follow-up MRI (from 6 months to 20 months).
  
  
  CONCLUSIONS
  The postoperative course of MRI abnormality surrounding tumour might be predictable from the intensity and ADC on preoperative DWI. Since MRI abnormalities associated with meningiomas can cause preoperative neurologic deficits. We hypothesise that abnormalities with restricted diffusion will be more likely to be associated with a preoperative deficit, and more likely to remain after removal of the causative meningioma.
authors.affiliation: Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, 812-8582, Fukuoka, Japan. nakamizo@ns.med.kyushu-u.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Nakamizo
authors.forename: Takanori
authors.initials: T
authors.lastname: Inamura
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Inoha
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Amano
authors.forename: Kiyonobu
authors.initials: K
authors.lastname: Ikezaki
authors.forename: Shunji
authors.initials: S
authors.lastname: Nishio
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Masashi
authors.initials: M
authors.lastname: Fukui
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002551:Cerebral Ventricle Neoplasms / Q000473:pathology / Q000601:surgery; D002552:Cerebral Ventricles / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology / Q000601:surgery*; D008579:Meningioma / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000473:pathology; D011184:Postoperative Period; D011300:Preoperative Care