title: Computerized Angiographic Occlusion Rating for Ruptured Clipped Aneurysms is Superior to Subjective Occlusion Rating.
abstract: OBJECTIVE
  The computerized occlusion rating to estimate angiographic occlusion of embolized aneurysms is superior to the subjective occlusion rating. In this study, we compared the 2 methods in the analysis of aneurysms clipped after subarachnoid hemorrhage.
  
  
  METHODS
  The pre- and postoperative angiographic images (DSA) of 95 selected patients were analyzed and stratified in 4 grades (grade 0 for 100%, grade I for <99%-90%, grade II for <89%-70%, grade III for <70% occlusion) by using the subjective (angiographic) occlusion rating and the computerized (angiographic) occlusion rating. For the subjective occlusion rating, the occlusion rate was estimated; for the computerized occlusion rating, the "occluded" and "nonoccluded" aneurysm areas were automatically calculated in square millimeters after outlining the ideal occlusion line.
  
  
  RESULTS
  With the subjective occlusion rating, 75 (78.9%), 12 (12.6%), 7 (7.4%), and 1 (1.1%) and with the computerized occlusion rating 45 (47.4%), 24 (25.3%), 20 (21.0%), and 6 (6.3%) patients had aneurysms stratified to grades 0, I, II and III, respectively. The interobserver variation was significant with the subjective occlusion rating but not with the computerized occlusion rating. The subjective occlusion rating overestimated aneurysm occlusion in 30 (31.6%) patients. Mean values were the following: subjective occlusion rating of 97.5 ± 6.3% and computerized occlusion rating of 93.5 ± 9.7%; P = < .001. No patient rebled, and 4 patients underwent retreatment during 36 ± 38.9 months; the predictive value (log-rank, Kaplan-Meier) of the subjective and computerized occlusion ratings with respect to retreatment was highly significant for both methods (subjective occlusion rating: χ(2), 29.65; P < .001; computerized occlusion rating: χ(2), 35.57, P < .001).
  
  
  CONCLUSIONS
  The 2 methods showed remarkable differences in the estimation of the angiographic occlusion rates of clipped aneurysms. The clearly lower interobserver variation of the computerized versus subjective occlusion rating may indicate a superiority of the computerized occlusion rating.
authors.affiliation: From the Departments of Neurosurgery (A.R.A.-S., P.W., M.L., M.K., S.E., B.R.) a.al-schameri@salk.at.
authors.forename: A R
authors.identifier: http://orcid.org/0000-0003-0555-8428
authors.initials: AR
authors.lastname: Al-Schameri
authors.affiliation: Department of Neuroradiology (G.B.), University Hospitals of Zurich, Zurich, Switzerland.
authors.forename: G
authors.identifier: http://orcid.org/0000-0001-5369-7364
authors.initials: G
authors.lastname: Baltsavias
authors.affiliation: From the Departments of Neurosurgery (A.R.A.-S., P.W., M.L., M.K., S.E., B.R.).
authors.forename: P
authors.initials: P
authors.lastname: Winkler
authors.affiliation: From the Departments of Neurosurgery (A.R.A.-S., P.W., M.L., M.K., S.E., B.R.).
authors.forename: M
authors.initials: M
authors.lastname: Lunzer
authors.affiliation: From the Departments of Neurosurgery (A.R.A.-S., P.W., M.L., M.K., S.E., B.R.).
authors.forename: M
authors.identifier: http://orcid.org/0000-0003-3496-8872
authors.initials: M
authors.lastname: Kral
authors.affiliation: Neuroradiology (L.M., F.W.), Paracelsus Private Medical University, Salzburg, Austria.
authors.forename: L
authors.initials: L
authors.lastname: Machegger
authors.affiliation: Neuroradiology (L.M., F.W.), Paracelsus Private Medical University, Salzburg, Austria.
authors.forename: F
authors.initials: F
authors.lastname: Weymayr
authors.affiliation: From the Departments of Neurosurgery (A.R.A.-S., P.W., M.L., M.K., S.E., B.R.).
authors.forename: S
authors.initials: S
authors.lastname: Emich
authors.affiliation: Department of Neurosurgery (C.S.), Krankenanstalt Rudolfstiftung, Vienna, Austria.
authors.forename: C
authors.initials: C
authors.lastname: Sherif
authors.affiliation: From the Departments of Neurosurgery (A.R.A.-S., P.W., M.L., M.K., S.E., B.R.).
authors.forename: B
authors.initials: B
authors.lastname: Richling
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography; D003198:Computer Simulation; D004621:Embolization, Therapeutic / Q000295:instrumentation; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D013525:Surgical Instruments; D016896:Treatment Outcome