title: Diagnostic accuracy of CT angiography with matched mask bone elimination for detection of intracranial aneurysms: comparison with digital subtraction angiography and 3D rotational angiography.
abstract: OBJECTIVE
  Our aim was to determine the diagnostic accuracy of multisection CT angiography combined with matched mask bone elimination (CTA-MMBE) for detection of intracranial aneurysms compared with digital subtraction angiography (DSA) and 3D rotational angiography (3DRA).
  
  
  METHODS
  Between January 2004 and February 2006, 108 patients who presented with clinically suspected subarachnoid hemorrhage underwent both CTA-MMBE and DSA for diagnosis of an intracranial aneurysm. Two neuroradiologists, independently, evaluated 27 predefined vessel locations in the CTA-MMBE images for the presence of an aneurysm. After consensus, diagnostic accuracy of CTA was calculated per predefined location and per patient. Interobserver agreement was calculated with kappa statistics.
  
  
  RESULTS
  In 88 patients (81%), 117 aneurysms (82 ruptured, 35 unruptured) were present on DSA. CTA-MMBE detected all ruptured aneurysms except 1. Overall specificity, sensitivity, positive predictive value, and negative predictive value of CTA-MMBE were 0.99, 0.90, 0.98, and 0.95 per patient and 0.91, 1.00, 0.97, and 0.99 per location, respectively. Sensitivity was 0.99 for aneurysms >/=3 mm and 0.38 for aneurysms <3 mm. Interobserver agreement for aneurysm detection was excellent (kappa value of 0.92 per location and 0.80 per patient).
  
  
  CONCLUSIONS
  CTA-MMBE is accurate in detecting intracranial aneurysms in any projection without overprojecting bone. CTA-MMBE has limited sensitivity in detecting very small aneurysms. Our data suggest that DSA and 3DRA can be limited to the vessel harboring the ruptured aneurysm before endovascular treatment, after detection of a ruptured aneurysm with CTA.
authors.affiliation: Department of Radiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. c.b.majoie@amc.uva.nl
authors.forename: M
authors.initials: M
authors.lastname: Romijn
authors.forename: H A F
authors.initials: HA
authors.lastname: Gratama van Andel
authors.forename: M A
authors.initials: MA
authors.lastname: van Walderveen
authors.forename: M E
authors.initials: ME
authors.lastname: Sprengers
authors.forename: J C
authors.initials: JC
authors.lastname: van Rijn
authors.forename: W J
authors.initials: WJ
authors.lastname: van Rooij
authors.forename: H W
authors.initials: HW
authors.lastname: Venema
authors.forename: C A
authors.initials: CA
authors.lastname: Grimbergen
authors.forename: G J
authors.initials: GJ
authors.lastname: den Heeten
authors.forename: C B
authors.initials: CB
authors.lastname: Majoie
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015901:Angiography, Digital Subtraction / Q000379:methods*; D002533:Cerebral Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012399:Rotation; D012680:Sensitivity and Specificity; D012886:Skull / Q000000981:diagnostic imaging*; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*