title: Feasibility of flat panel angiographic CT after intravenous contrast agent application in the postoperative evaluation of patients with clipped aneurysms.
abstract: OBJECTIVE
  Important findings, such as aneurysm remnants or major arterial occlusion, can be detected on intra- or postoperative angiography after surgical clipping of intracranial aneurysms. The purpose of this study was to evaluate the feasibility of IV-ACT for the postoperative detection of residual aneurysms and parent vessel patency compared with IA-DSA, which was selected as the standard reference method.
  
  
  METHODS
  Twenty-two patients with 27 aneurysms treated by surgical clipping were examined by using both IA-DSA and IV-ACT. Both diagnostic procedures were performed on an FPD-equipped angiography system. Postprocessing of IV-ACT acquisitions was performed on a dedicated workstation producing multiplanar reformations and maximum intensity projections of the clip region and other intracranial arteries. Three interventional neuroradiologists independently evaluated both procedures.
  
  
  RESULTS
  A residual aneurysm was delineated in 10 cases with IA-DSA. Sufficient opacification of the intracranial vessels was assigned in 26 IV-ACT cases. Due to metal artifacts, IV-ACT images were tagged as "not diagnostic" on 8 occasions. In the other 19 aneurysms, a residual aneurysm was delineated in 6 cases-all 6 being true-positive compared with IA-DSA-and was excluded in the remaining 13 cases-all true-negative. Even small aneurysm remnants with a diameter of 1.5 mm were detected with IV-ACT.
  
  
  CONCLUSIONS
  Currently IV-ACT cannot be recommended as a routine tool for postoperative evaluation of clipped aneurysms due to metal artifacts in 30% of the examinations. These artifacts appear with multiple normal-sized or large clips. In patients with single or multiple small clips, IV-ACT can reliably show aneurysm remnants.
authors.affiliation: Department of Neuroradiology, University Medicine Goettingen, Germany. m.psychogios@med.uni-goettingen.de
authors.forename: M-N
authors.initials: MN
authors.lastname: Psychogios
authors.forename: D
authors.initials: D
authors.lastname: Wachter
authors.forename: A
authors.initials: A
authors.lastname: Mohr
authors.forename: P
authors.initials: P
authors.lastname: Schramm
authors.forename: A-M
authors.initials: AM
authors.lastname: Frölich
authors.forename: K
authors.initials: K
authors.lastname: Jung
authors.forename: V
authors.initials: V
authors.lastname: Rohde
authors.forename: M
authors.initials: M
authors.lastname: Knauth
mesh_terms: D000328:Adult; D000368:Aged; D002533:Cerebral Angiography / Q000295:instrumentation*; D003287:Contrast Media / Q000008:administration & dosage; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000601:surgery*; D007479:Iopamidol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*; D016896:Treatment Outcome; D014963:X-Ray Intensifying Screens
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol