title: Statistical analysis of multi-b factor diffusion weighted images can help distinguish between vasogenic and tumor-infiltrated edema.
abstract: OBJECTIVE
  The diffusion model can be transformed into a multicompartment model by means of multi-b factor diffusion-weighted sequences. We adapted a method of statistical analysis of these images and evaluated its performance to distinguish tumor-infiltrated edema from vasogenic edema.
  
  
  METHODS
  Forty-nine patients with infiltrating tumors (38 patients: low to high-grade gliomas) or vasogenic edema (11 patients: metastases, abscess, extra-axial lesions) were studied by multi-b factor diffusion-weighted imaging. Comparison of histological results and morphological and perfusion MRI defined 69 characteristic volumes of interest in the peritumoral edema of 69 distinct infiltrating lesions (40) or lesions inducing vasogenic edema (29).
  
  
  RESULTS
  The factorial analysis had a sensitivity of 92.9% and a specificity of 90.6% between tumor-infiltrated and vasogenic edema. Simplified interpretation confined to values of the high and mean diffusivity compartments had a sensitivity of 87.5% and a specificity of 89.2% between strictly tumor-infiltrated edema and vasogenic edema with the advantage of simplified interpretation based on two-color parametric mapping.
  
  
  CONCLUSIONS
  Discrimination between tumor-infiltrated edema and vasogenic edema can be achieved by means of a 90-s multi-b factor diffusion-weighted sequence and factorial analysis. Simplified visual and quantitative interpretation of the results should also allow integration of multi-b factor analysis into routine neuroradiology practice.
authors.affiliation: C.H.U. Bicêtre AP-HP, Neuroradiology, Le Kremlin-Bicêtre, France; CNRS, UMR 8081, Le Kremlin-Bicêtre, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Vandendries
authors.forename: Denis
authors.initials: D
authors.lastname: Ducreux
authors.forename: Catherine
authors.initials: C
authors.lastname: Lacroix
authors.forename: Béatrice
authors.initials: B
authors.lastname: Ducot
authors.forename: Guillaume
authors.initials: G
authors.lastname: Saliou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001929:Brain Edema / Q000473:pathology*; D001932:Brain Neoplasms / Q000473:pathology*; D003287:Contrast Media; D003627:Data Interpretation, Statistical; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005910:Glioma; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D060787:Neoplasm Grading; D009942:Organometallic Compounds; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine
keywords: brain; factorial analysis; multi-b DWI; tumor-infiltrated edema; vasogenic edema