title: Hyperdense basilar artery sign-a reliable sign of basilar artery occlusion.
abstract: BACKGROUND
  We aimed to investigate the value of the hyperdense basilar artery (HBA) sign and of basilar artery (BA) attenuation measurements as predictors of basilar artery occlusion (BAO) on nonenhanced cranial CT (NECT).
  
  
  METHODS
  Forty-one consecutive patients with proven BAO in CT angiography, who had undergone NECT for initial evaluation (30 males, 11 females) were retrospectively included. Another 41 age-matched patients without BAO were included as a control group. The NECT scans of both groups were assessed by three independent blinded readers (staff, fellow, and resident) in a randomized reading order using a standardized semiquantitative questionnaire. Visual BA hyperdensity, including the presence of HBA sign (hyperdensity scores of 4 and 5/5), was assessed, quantitative BA attenuation was measured in a region of interest (ROI), and diagnosis of BAO was made before and after ROI measurements. For statistical analysis, multivariate mixed effects models, likelihood ratio tests, and receiver operating characteristics techniques were applied.
  
  
  RESULTS
  HBA sign had a relatively low sensitivity (60.98-65.85%), specificity (70.73-90.24%), and accuracy (65.85-75.61%) for the presence/absence of BAO on NECT. Optimal cut-off points were 40-42 HU (sensitivity, 68.29-78.05%; specificity, 75.61-82.93%; accuracy, 74.39-80.49%).
  
  
  CONCLUSIONS
  In basilar artery occlusion, quantitative measurement of BA attenuation can slightly improve the diagnostic predictiveness of NECT. However, even with optimal cut-off values, the sensitivity is too low to serve as the sole diagnostic decision-making tool.
authors.affiliation: Institute of Clinical Radiology, Ludwig-Maximilians-University, Grosshadern Campus, Marchioninistr. 15, 81377 Munich, Germany.
authors.forename: Lara
authors.initials: L
authors.lastname: Connell
authors.forename: Inga Katharina
authors.initials: IK
authors.lastname: Koerte
authors.forename: Ruediger Paul
authors.initials: RP
authors.lastname: Laubender
authors.forename: Dominik
authors.initials: D
authors.lastname: Morhard
authors.forename: Jennifer
authors.initials: J
authors.lastname: Linn
authors.forename: Hans Christoph
authors.initials: HC
authors.lastname: Becker
authors.forename: Maximilian
authors.initials: M
authors.lastname: Reiser
authors.forename: Hartmut
authors.initials: H
authors.lastname: Brueckmann
authors.forename: Birgit
authors.initials: B
authors.lastname: Ertl-Wagner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging*; D001488:Basilar Artery / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012044:Regression Analysis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014715:Vertebrobasilar Insufficiency / Q000000981:diagnostic imaging*