title: Interobserver variability in the detection of cerebral venous thrombosis using CT venography with matched mask bone elimination.
abstract: OBJECTIVE
  Computed tomography venography (CTV) has proven to be a reliable imaging method in the evaluation of cerebral venous thrombosis with good correlation to magnetic resonance (MR) imaging and digital subtraction angiography (DSA). It is fast and widely accessible, especially in the emergency setting. For better visualization of vascular structures bone is often removed from the images. The purpose of this study was to evaluate the quality of a fully automatic bone removal method, matched mask bone elimination (MMBE), and to assess the interobserver variability of the CTV technique.
  
  
  METHODS
  Fifty patients with clinical suspicion of cerebral venous thrombosis underwent multislice CTV with MMBE post-processing. Axial source images and maximum intensity projections were retrospectively evaluated by two neuroradiologists for quality of bone removal and for the presence or absence of thrombosis in nine dural sinuses and five deep cerebral veins. A per sinus/vein and a per patient analysis (thrombosis in at least one sinus or vein) was performed and interobserver agreement was assessed.
  
  
  RESULTS
  Both observers considered bone removal good in all patients (100%). Interobserver agreement per patient was excellent (kappa=0.83), with a full agreement in 47 of 50 patients (94%). The interobserver agreement per sinus or vein was good (kappa=0.76), with a full agreement in 679 of 700 sinuses or veins (97%).
  
  
  CONCLUSIONS
  CTV aided with MMBE is a robust technique for visualization of the intracranial venous circulation, removing bone effectively. CTV has high interobserver agreement for presence or absence of cerebral venous thrombosis.
authors: Department of Biomedical Engineering & Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors: Hugo A
authors: HA
authors: Gratama van Andel
authors: Leonard J
authors: LJ
authors: van Boven
authors: Marianne A
authors: MA
authors: van Walderveen
authors: Henk W
authors: HW
authors: Venema
authors: Jeroen C
authors: JC
authors: van Rijn
authors: Jan
authors: J
authors: Stam
authors: Cornelis A
authors: CA
authors: Grimbergen
authors: Gerard J
authors: GJ
authors: den Heeten
authors: Charles B
authors: CB
authors: Majoie
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography; D002648:Child; D002675:Child, Preschool; D003392:Cranial Sinuses / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007223:Infant; D020767:Intracranial Thrombosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010690:Phlebography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult