title: Accuracy of CT angiography in detection of blood supply dominance of posterior cerebral artery in patients with posterior communicating artery aneurysm.
abstract: OBJECTIVE
  The use of computed tomography angiography (CTA) as the sole vascular imaging study for preoperative planning for clipping of aneurysms is well described in the literature. CTA is widely available, provides quick acquisition, has low morbidity, and low cost. In this study, we describe the accuracy of CTA in determining the blood supply dominance in comparison to standard digital subtraction angiography.
  
  
  METHODS
  Sixty-six patients, with both CTAs and angiograms, were reviewed by two independent neuroradiologists. The posterior cerebral artery was determined to have dominant supply from the posterior communicating artery if it was of similar size to the P2 segment and the P1 segment was smaller by approximately 50%. If the posterior communicating artery and P1 segment were the same size, it was considered to have a dual supply. If P1 and P2 segments were the same caliber and the posterior communicating artery was smaller by 50%, it was deemed to have posterior circulation dominance.
  
  
  RESULTS
  Based on the findings of our reviewers, CTA had a sensitivity and specificity of 69% and 96%, respectively, in predicting the presence of a fetal PCA. The positive predictive value was found to be 82% while a negative predictive value was estimated as 93%. A small-caliber P1 segment and large-caliber posterior communicating artery led to inaccurate interpretations of the CTAs.
  
  
  CONCLUSIONS
  This study shows that one cannot accurately predict blood supply dominance of the posterior cerebral artery. Knowledge of the blood flow dominance is essential when clipping a posterior communicating artery aneurysm to avoid compromise in posterior circulation.
authors.affiliation: Louisiana State University Health Science Center, USA.
authors.forename: Osama
authors.initials: O
authors.lastname: Ahmed
authors.affiliation: Louisiana State University Health Science Center, USA.
authors.forename: Piyush
authors.initials: P
authors.lastname: Kalakoti
authors.affiliation: Louisiana State University Health Science Center, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Menger
authors.affiliation: Mayo Clinic Jacksonville, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Brown
authors.affiliation: Louisiana State University Health Science Center, USA.
authors.forename: Shihao
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Louisiana State University Health Science Center, USA.
authors.forename: Bharat
authors.initials: B
authors.lastname: Guthikonda
authors.affiliation: Louisiana State University Health Science Center, USA hcuell@lsuhsc.edu.
authors.forename: Hugo
authors.initials: H
authors.lastname: Cuellar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D002533:Cerebral Angiography / Q000379:methods; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000601:surgery; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D020769:Posterior Cerebral Artery / Q000000981:diagnostic imaging* / Q000601:surgery; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D055815:Young Adult
keywords: CT angiography; CT imaging; digital subtraction angiography; posterior cerebral artery