title: Aneurysms of the posterior circulation: detection and treatment planning using volume-rendered three-dimensional helical computerized tomography angiography.
abstract: OBJECTIVE
  The aim of this study was to determine whether computerized tomography (CT) angiography could be used to identify and characterize aneurysms of the posterior circulation and guide optimal treatment selection, and how data obtained using this method compared with intraoperative findings.
  
  
  METHODS
  Patients suspected of harboring brain aneurysms underwent CT angiography and digital subtraction (DS) angiography; the results were prospectively interpreted by blinded independent evaluators. All patients with posterior circulation aneurysms were consecutively enrolled in the study. After treatment, neurosurgeons and endovascular therapists evaluated the ability of CT and DS angiography to demonstrate features of the lesions important for triage between treatment options (Wilcoxon signed-rank test) and to allow for coil or clip preselection and complete treatment planning (McNemar test of proportions), while using intraoperative findings as the basis of truth. In 242 patients overall, CT angiography detected 38 aneurysms and two aneurysmal blisters in 32 patients. The sensitivity of CT angiography in revealing posterior circulation aneurysms was 100% compared with DS angiography, with no false-positive results. Furthermore, CT angiography was sufficient as the sole study at triage for 65% of the posterior circulation aneurysms (26 of 40 lesions; p < 0.001), including 62% of the complex lesions (p < 0.001), and permitted coil or clip preselection in 74% of treated cases (20 of 27 cases; p < 0.002). Results of CT angiography revealed information about mural calcification and intraluminal thrombus not available on DS angiography, which affected patient care.
  
  
  CONCLUSIONS
  In this study population, CT angiography was comparable to DS angiography in the detection and characterization of aneurysms of the posterior circulation. Computerized tomography angiography was used successfully to triage patients between endovascular and neurosurgical treatment options in a significant proportion of cases and permitted treatment planning in more than 70% of treated cases.
authors.affiliation: Department of Radiological Sciences, University of California at Los Angeles 90095-1721, USA. pvillablanca@mednet.ucla.edu
authors.forename: J Pablo
authors.initials: JP
authors.lastname: Villablanca
authors.forename: Adina
authors.initials: A
authors.lastname: Achiriolaie
authors.forename: Parizad
authors.initials: P
authors.lastname: Hooshi
authors.forename: Neil
authors.initials: N
authors.lastname: Martin
authors.forename: Gary
authors.initials: G
authors.lastname: Duckwiler
authors.forename: Reza
authors.initials: R
authors.lastname: Jahan
authors.forename: John
authors.initials: J
authors.lastname: Frazee
authors.forename: Pierre
authors.initials: P
authors.lastname: Gobin
authors.forename: James
authors.initials: J
authors.lastname: Sayre
authors.forename: Fernando
authors.initials: F
authors.lastname: Viñuela
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction / Q000592:standards; D004621:Embolization, Therapeutic / Q000295:instrumentation; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D010347:Patient Care Planning; D016037:Single-Blind Method; D013525:Surgical Instruments; D036542:Tomography, Spiral Computed / Q000592:standards; D014218:Triage / Q000379:methods