title: The venous distension sign: a diagnostic sign of intracranial hypotension at MR imaging of the brain.
abstract: OBJECTIVE
  Patients with intracranial hypotension (IH) demonstrate intracranial venous enlargement with a characteristic change in contour of the transverse sinus seen on routine T1-weighted sagittal imaging. In IH, the inferior margin of the midportion of the dominant transverse sinus acquires a distended convex appearance; we have termed this the venous distension sign (VDS). This is distinct from the normal appearance of this segment, which usually has a slightly concave or straight lower margin. This sign is introduced, and its performance as a test for the presence of this disease is evaluated.
  
  
  METHODS
  The transverse sinuses on T1-weighted sagittal imaging of 15 patients with IH and 15 control patients were independently assessed in a blinded fashion by 3 readers for the presence of a VDS. A present or absent VDS was determined for each patient by each reader, and a consensus result for each patient was determined by unanimity or majority rule.
  
  
  RESULTS
  Using the VDS, the readers correctly identified 93% (14 of 15) of the IH patients and similarly 93% (14 of 15) of the control patients. There was a high rate of agreement among the readers for the interpretation of the VDS (multirater kappa = 0.82). The overall sensitivity of the VDS for the diagnosis of intracranial hypotension was 94%. Specificity was also 94%.
  
  
  CONCLUSIONS
  The VDS appears to be an accurate test for the presence or absence of IH and may be helpful in the evaluation of these patients.
authors.affiliation: Department of Medical Imaging, Division of Neuroradiology, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada. richard.farb@utoronto.ca
authors.forename: R I
authors.initials: RI
authors.lastname: Farb
authors.forename: R
authors.initials: R
authors.lastname: Forghani
authors.forename: S K
authors.initials: SK
authors.lastname: Lee
authors.forename: D J
authors.initials: DJ
authors.lastname: Mikulis
authors.forename: R
authors.initials: R
authors.lastname: Agid
mesh_terms: D001921:Brain / Q000473:pathology*; D002550:Cerebral Veins / Q000473:pathology*; D005260:Female; D006801:Humans; D019585:Intracranial Hypotension / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016037:Single-Blind Method