title: Improved arterial visualization in cerebral CT perfusion-derived arteriograms compared with standard CT angiography: a visual assessment study.
abstract: OBJECTIVE
  Invasive cerebral DSA has largely been replaced by CTA, which is noninvasive but has a compromised arterial view due to superimposed bone and veins. The purpose of this study was to evaluate whether arterial visualization in CTPa is superior to standard CTA, which would eliminate the need for an additional CTA scan to assess arterial diseases and therefore reduce radiation dose.
  
  
  METHODS
  In this study, we included 24 patients with subarachnoid hemorrhage for whom CTA and CTP were available. Arterial quality and presence of superimposed veins and bone in CTPa were compared with CTA and scored by 2 radiologists by using a VAS (0%-100%). Average VAS scores were determined and VAS scores per patient were converted to a 10-point NRS. Arterial visualization was considered to be improved when the highest rate (NRS 10, VAS > 90%) was scored for arterial quality, and the lowest rate (NRS 1, VAS < 10%), for the presence of superimposed veins and bone. A sign test with continuity correction was used to test whether the number of cases with these rates was significant.
  
  
  RESULTS
  Average VAS scores in the proximal area were 94% (arterial quality), 4% (presence of bone), and 7% (presence of veins). In this area, the sign test showed that a significant number of cases scored NRS 10 for arterial quality (P < .02) and NRS 1 for the presence of superimposed veins and bone (P < .01).
  
  
  CONCLUSIONS
  Cerebral CTPa shows improved arterial visualization in the proximal area compared with CTA, with similar arterial quality but no superimposed bone and veins.
authors.affiliation: Image Sciences Institute, University Medical Center Utrecht, Utrecht, the Netherlands. a.m.mendrik@gmail.com
authors.forename: A M
authors.initials: AM
authors.lastname: Mendrik
authors.forename: E P A
authors.initials: EP
authors.lastname: Vonken
authors.forename: G A P
authors.initials: GA
authors.lastname: de Kort
authors.forename: B
authors.initials: B
authors.lastname: van Ginneken
authors.forename: E J
authors.initials: EJ
authors.lastname: Smit
authors.forename: M A
authors.initials: MA
authors.lastname: Viergever
authors.forename: M
authors.initials: M
authors.lastname: Prokop
mesh_terms: D000368:Aged; D002533:Cerebral Angiography / Q000379:methods*; D002536:Cerebral Arteries / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*