title: Perfusion-weighted imaging of peritumoral edema can aid in the differential diagnosis of glioblastoma mulltiforme versus brain metastasis.
abstract: BACKGROUND
  MRI differentiation between metastases and high grade gliomas is a challenging task. Contrast enhancement and size of edema do not provide clear-cut differentiators. The differences in the properties of the peritumoral edema between these tumor types may be exploited to distinguish between them, using MRI perfusion sequences, which are capable of imaging edema in the clinical setting and may be a reliable method to make this differentiation.
  
  
  OBJECTIVE
  To assess the ability of perfusion-weighted imaging to differentiate between high grade gliomas andbrain metastases.
  
  
  METHODS
  During 5 months, 21 patients (age 40-85, median age 61, 16 males and 5 females) with either glioblastoma multiforme (GBM) or metastasis (pathology proven), underwent MRI for assessment of the tumor prior to surgery. Most of the scans were done at 3 Tesla. The scans included perfusion-weighted imaging sequences. Perfusion in the tumor, in the peritumoral edema and in normal tissue were assessed using Functool software. The ratios of tumor perfusion and peritumoral edema perfusion to normal tissue perfusion were calculated and compared.
  
  
  RESULTS
  Bleeding artifact precluded perfusion assessment in four patients. There was no statistically significant difference between the tumor perfusion ratios of high grade gliomas and those of metastases. The edema perfusion ratios were higher in GBM than in metastases (P = 0.007).
  
  
  CONCLUSIONS
  Perfusion-weighted imaging of peritumoral edema can help to differentiate between GBM and metastases.
authors.affiliation: Department of Diagnostic Imaging, Sheba Medical Center, Tel Hashomer, Israel. osnatx@gmail.com
authors.forename: Osnat
authors.initials: O
authors.lastname: Halshtok Neiman
authors.forename: Siegal
authors.initials: S
authors.lastname: Sadetzki
authors.forename: Angela
authors.initials: A
authors.lastname: Chetrit
authors.forename: Stephen
authors.initials: S
authors.lastname: Raskin
authors.forename: Gal
authors.initials: G
authors.lastname: Yaniv
authors.forename: Chen
authors.initials: C
authors.lastname: Hoffmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D003287:Contrast Media; D003937:Diagnosis, Differential; D004487:Edema / Q000175:diagnosis*; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012984:Software; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media