title: CT density measurement and H:H ratio are useful in diagnosing acute cerebral venous sinus thrombosis.
abstract: OBJECTIVE
  Brain CT is widely used to exclude or confirm acute cerebral venous sinus thrombosis. The purpose of this study was to assess the value of attenuation measurement and the H:H ratio on unenhanced brain CT scans in the diagnosis of acute cerebral venous sinus thrombosis.
  
  
  METHODS
  This retrospective study evaluated 20 patients with acute cerebral venous sinus thrombosis and 20 age- and sex-matched control participants without thrombosis. Three experienced observers independently evaluated the unenhanced brain CT scan for the presence of cerebral venous sinus thrombosis and measured the attenuation in the dural sinuses. Interreader differences were examined, as well as densities and H:H ratio between patients with acute cerebral venous sinus thrombosis and control participants.
  
  
  RESULTS
  A significant difference in the average sinus attenuation was found between patients with acute cerebral venous sinus thrombosis (73.9 ± 9.2 HU) and the control group (52.8 ± 6.7 HU; P < .0001). A similar difference was found for the H:H ratio (1.91 ± 0.32 vs 1.33 ± 0.12 in patients with and without cerebral venous sinus thrombosis, respectively; P < .0001). Optimal thresholds of 62 HU and 1.52 lead to accuracies of 95% for average sinus attenuation and 97.5% for the H:H ratio, respectively.
  
  
  CONCLUSIONS
  Hyperattenuation and the H:H ratio in the dural sinuses on unenhanced brain CT scans have a high accuracy in the detection of acute cerebral venous sinus thrombosis.
authors.affiliation: Department of Radiology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: P-J
authors.initials: PJ
authors.lastname: Buyck
authors.forename: F
authors.initials: F
authors.lastname: De Keyzer
authors.forename: D
authors.initials: D
authors.lastname: Vanneste
authors.forename: G
authors.initials: G
authors.lastname: Wilms
authors.forename: V
authors.initials: V
authors.lastname: Thijs
authors.forename: P
authors.initials: P
authors.lastname: Demaerel
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000465:Algorithms; D002533:Cerebral Angiography / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012851:Sinus Thrombosis, Intracranial / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult