title: MDCT angiography for detection and quantification of small intracranial arteries: comparison with conventional catheter angiography.
abstract: OBJECTIVE
  MDCT angiography can serve as an alternative to digital subtraction catheter angiography for the study of large and medium-sized arteries. Our goal was to achieve a better understanding of the capabilities and limitations of both MDCT angiography and digital subtraction angiography in the evaluation of intracranial arteries with an average diameter of 1.5 mm or less.
  
  
  METHODS
  A blinded retrospective analysis of the presence and size of nine small cerebral arteries on both 2D and 3D CT angiography (CTA) was conducted with 27 patients who had normal findings at CTA and digital subtraction angiography. Scans of 455 arterial segments obtained with either 4-MDCT or 16-MDCT were examined by two independent blinded reviewers. The sensitivity and specificity of CTA for each vessel were established. A chi-square test was used to determine interoperator reliability.
  
  
  RESULTS
  The smallest arterial size reliably detected with MDCT angiography with our imaging and postprocessing protocol was 0.7 mm versus 0.4 mm for digital subtraction angiography. Interoperator reliability for vessel identification with MDCT angiography was 97% without significant differences in detection rates between 4-MDCT and 16-MDCT. Two-dimensional CTA depicted more than 90% of arteries studied but only 63% of anterior choroidal arteries and 27% of recurrent arteries of Heubner. There were no significant differences in mean arterial sizes measured with 2D CTA versus digital subtraction angiography for six of nine arteries. In six of nine arterial segments with a mean diameter of 1 mm or less, fewer arterial segments were visualized on 3D CTA than on 2D CTA.
  
  
  CONCLUSIONS
  Except for the recurrent artery of Heubner and the anterior choroidal artery, MDCT angiography depicted 90% or more of all examined small intracranial arteries detected with digital subtraction angiography. The mean sensitivity was 0.91, and the mean specificity was 0.7.
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine at the University of California, Los Angeles, 10833 Le Conte Ave., Rm. B3-115 CHS, Los Angeles, CA 90095-1721, USA.
authors.forename: J Pablo
authors.initials: JP
authors.lastname: Villablanca
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Rodriguez
authors.forename: Tyler
authors.initials: T
authors.lastname: Stockman
authors.forename: Sonia
authors.initials: S
authors.lastname: Dahliwal
authors.forename: Michelle
authors.initials: M
authors.lastname: Omura
authors.forename: Saman
authors.initials: S
authors.lastname: Hazany
authors.forename: James
authors.initials: J
authors.lastname: Sayre
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D006328:Cardiac Catheterization / Q000379:methods; D002536:Cerebral Arteries / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*