title: PWI-MRI and contrast extravasation in brain AVM help to estimate angiogenic activity.
abstract: BACKGROUND
  The aim of this study is to investigate perfusion characteristics of brain arteriovenous malformation (AVM) by means of MRI perfusion-weighted imaging (PWI).
  
  
  METHODS
  Forty-three patients with brain AVM were prospectively included and investigated by PWI-MRI. Diagnosis of type of disease was made by angiogram. According to angiographic features, the study group was classified in three groups: two groups of patients with classical AVM (group 1 with few or no angiogenic feature (13 patients) and group 2 with many angiogenic features (18 patients)) and one group (group 3) which included patients with cerebral proliferative angiopathy (CPA; 12 patients). Twenty-one patients had never been treated endovascularly for their AVM and 22 patients received partial treatment by endovascular embolisation. Through PWI, corrected cerebral blood volume (CBVc), mean transit time (MTT), and percentage of microvascular leakage (MVL) as an indirect measure of permeability were assessed.
  
  
  RESULTS
  The three patient groups did not differ significantly in baseline and clinical parameters. CBVc, MTT, and MVL differed significantly between the three groups (p = 0.003, p = 0.04, p = 0.01, respectively), with the lowest mean values found in group 1 and the highest in group 3. Mean MVL was 11.4 in group 1, 18.6 in group 2, and 21.9 in group 3.
  
  
  CONCLUSIONS
  MRI can demonstrate differences in PWI parameters among patients with classical AVM and CPA, which are related to angiographic features of these AVMs. Through PWI, the level of angiogenic activity in AVMs may be monitored.
authors.affiliation: Service de Neuroradiologie, Hôpital de Bicêtre, 78 rue du Général Leclerc, 94275, Kremlin Bicêtre cedex, France. guillaume.saliou@bct.aphp.fr
authors.forename: Guillaume
authors.initials: G
authors.lastname: Saliou
authors.forename: Timo
authors.initials: T
authors.lastname: Krings
authors.forename: Dik R
authors.initials: DR
authors.lastname: Rutgers
authors.forename: Frederique
authors.initials: F
authors.lastname: Toulgoat
authors.forename: Augustin
authors.initials: A
authors.lastname: Ozanne
authors.forename: Pierre
authors.initials: P
authors.lastname: Lasjaunias
authors.forename: Denis
authors.initials: D
authors.lastname: Ducreux
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000098:blood supply*; D002533:Cerebral Angiography / Q000379:methods; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000175:diagnosis* / Q000473:pathology*; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D011446:Prospective Studies; D055815:Young Adult