title: Inter- and intraobserver variability in the assessment of brain arteriovenous malformation angioarchitecture and endovascular treatment results.
abstract: OBJECTIVE
  Several angiographic features of brain arteriovenous malformations (BAVMs) have been associated with an increased risk of hemorrhage. However, interpretation of these features may not be consistent between observers. We conducted a study to determine inter- and intraobserver agreement of various angioarchitectural characteristics of BAVM.
  
  
  METHODS
  Two experienced interventional neuroradiologists independently reviewed pre- and post-endovascular treatment angiograms from 50 consecutive patients. Axial CT and/or MR images before treatment were included. We collected the following data: Spetzler-Martin grades, number of involved arterial territories, associated aneurysms by location (circle of Willis, feeding artery, intranidal, and venous), and nidus reduction after endovascular treatment (<33%, 33%-66%, and >66%). The reviewers were compared with each other, and 1 was compared with himself after a 3-month interval. Measures of agreement were performed by using the kappa statistic (kappa) for nominal data and the weighted kappa for ordinal data.
  
  
  RESULTS
  Inter- and intraobserver agreement were higher for assessment of the Spetzler-Martin grade (weighted kappa = 0.70/0.75) and nidus size reduction after endovascular treatment (kappa = 0.74/0.77). Inter- and intraobserver agreement were inferior for findings concerning feeding artery aneurysms (kappa = 0.19/0.36), intranidal aneurysms (kappa = 0.34/0.35), and venous aneurysms (kappa = 0.50/0.67).
  
  
  CONCLUSIONS
  Angiographic characteristics of BAVMs considered as risk factors for hemorrhage, such as aneurysms, are not reliably detected on global angiograms between different observers. In contrast, the Spetzler-Martin grading system and angiographic results of endovascular treatment can be used with high observer agreement.
authors.affiliation: Department of Radiology, Interventional Neuroradiology Section, Centre Hospitalier de l'Université de Montréal, Notre-Dame Hospital, Montreal, PQ, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Iancu-Gontard
authors.forename: A
authors.initials: A
authors.lastname: Weill
authors.forename: F
authors.initials: F
authors.lastname: Guilbert
authors.forename: T
authors.initials: T
authors.lastname: Nguyen
authors.forename: J
authors.initials: J
authors.lastname: Raymond
authors.forename: D
authors.initials: D
authors.lastname: Roy
mesh_terms: D000328:Adult; D002533:Cerebral Angiography / Q000592:standards / Q000706:statistics & numerical data*; D015331:Cohort Studies; D004621:Embolization, Therapeutic; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000628:therapy*; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed