title: Relative filling time delay based on CT perfusion source imaging: a simple method to predict outcome in acute ischemic stroke.
abstract: OBJECTIVE
  Collateral vessel status is strongly associated with clinical outcome in ischemic stroke but can be challenging to assess. The aim of this study was to develop a tomography perfusion source imaging-based assessment of collateral vessel status.
  
  
  METHODS
  Consecutive patients with ischemic stroke who received intravenous thrombolysis or intra-arterial reperfusion therapy after CTP were retrospectively analyzed. In those with middle cerebral artery or internal carotid artery occlusion, CT perfusion source imaging was used to identify the relative filling time delay between the normal MCA Sylvian branches and those in the affected hemisphere. Receiver operating characteristic analysis and logistic regression were used to assess the association of the relative filling time delay with the 24-hour Alberta Stroke Program Early CT Score based on noncontrast CT and the 90-day modified Rankin Scale score.
  
  
  RESULTS
  There were 217 patients treated in 2009-2011 who had CTP data, of whom 60 had MCA or ICA occlusion and 55 had 90-day mRS data. The intraclass correlation coefficient for relative filling time delay was 0.95. Relative filling time delay was correlated with 24-hour ASPECTS (Spearman ρ=-0.674; P<.001) and 90-day mRS score (ρ=0.516, P<.01). Increased relative filling time delay was associated with poor radiologic outcome (ASPECTS, 0-7) (area under the curve=0.79, P<.001) and poor functional outcome (mRS score, 3-6) (area under the curve=0.77, P=.001). In multivariate logistic regression, the association of longer relative filling time delay with poor outcome remained significant, independent of age, sex, and baseline National Institutes of Health Stroke Scale score.
  
  
  CONCLUSIONS
  Relative filling time delay is a useful independent predictor of clinical outcome after ischemic stroke.
authors.affiliation: From the Department of Medicine and Neurology, Melbourne Brain Centre at the Royal Melbourne Hospital (W.C., B.C.V.C., S.M.D., B.Y.), University of Melbourne, Parkville, Victoria, Australia Department of Neurology (W.C., Q.D.), Huashan Hospital, Shanghai, China.
authors.forename: W
authors.initials: W
authors.lastname: Cao
authors.affiliation: From the Department of Medicine and Neurology, Melbourne Brain Centre at the Royal Melbourne Hospital (W.C., B.C.V.C., S.M.D., B.Y.), University of Melbourne, Parkville, Victoria, Australia.
authors.forename: B C V
authors.initials: BC
authors.lastname: Campbell
authors.affiliation: Department of Neurology (W.C., Q.D.), Huashan Hospital, Shanghai, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Dong
authors.affiliation: From the Department of Medicine and Neurology, Melbourne Brain Centre at the Royal Melbourne Hospital (W.C., B.C.V.C., S.M.D., B.Y.), University of Melbourne, Parkville, Victoria, Australia.
authors.forename: S M
authors.initials: SM
authors.lastname: Davis
authors.affiliation: From the Department of Medicine and Neurology, Melbourne Brain Centre at the Royal Melbourne Hospital (W.C., B.C.V.C., S.M.D., B.Y.), University of Melbourne, Parkville, Victoria, Australia Bernard.yan@mh.org.au.
authors.forename: B
authors.initials: B
authors.lastname: Yan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000416:Alberta; D001157:Arterial Occlusive Diseases / Q000150:complications / Q000000981:diagnostic imaging; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging; D002340:Carotid Artery Diseases / Q000150:complications / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging; D012372:ROC Curve; D020127:Recovery of Function; D012189:Retrospective Studies; D020521:Stroke / Q000000981:diagnostic imaging* / Q000209:etiology; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014481:United States
references.citation: N Engl J Med. 2013 Jun 20;368(25):2355-65
references.pmid: 23713578
references.citation: Stroke. 1998 May;29(5):935-8
references.pmid: 9596238
references.citation: J Cereb Blood Flow Metab. 2013 Mar;33(3):365-71
references.pmid: 23149554
references.citation: Stroke. 2004 Jun;35(6):1340-4
references.pmid: 15087564
references.citation: Int J Stroke. 2014 Jan;9(1):110-6
references.pmid: 22974139
references.citation: Stroke. 2009 Sep;40(9):3001-5
references.pmid: 19590055
references.citation: AJNR Am J Neuroradiol. 2012 Mar;33(3):576-82
references.pmid: 22135128
references.citation: AJNR Am J Neuroradiol. 1997 Jun-Jul;18(6):1001-10
references.pmid: 9194425
references.citation: Stroke. 2005 Oct;36(10):2110-5
references.pmid: 16166579
references.citation: Stroke. 2003 Aug;34(8):1925-31
references.pmid: 12843342
references.citation: Stroke. 2010 Oct;41(10):2316-22
references.pmid: 20829514
references.citation: J Neurol Neurosurg Psychiatry. 1988 Feb;51(2):269-72
references.pmid: 3346693
references.citation: Stroke. 2013 Aug;44(8):2194-9
references.pmid: 23760216
references.citation: J Comput Assist Tomogr. 2001 Jul-Aug;25(4):520-8
references.pmid: 11473180
references.citation: Stroke. 2000 Jan;31(1):128-32
references.pmid: 10625727
references.citation: AJNR Am J Neuroradiol. 2008 Sep;29(8):1471-5
references.pmid: 18599577
references.citation: AJNR Am J Neuroradiol. 2005 Aug;26(7):1789-97
references.pmid: 16091531
references.citation: Stroke. 1989 Jun;20(6):735-40
references.pmid: 2728038
references.citation: Ann Neurol. 2007 Jun;61(6):533-43
references.pmid: 17431875
references.citation: Stroke. 2011 Mar;42(3):693-9
references.pmid: 21233472
references.citation: Brain. 2009 Aug;132(Pt 8):2231-8
references.pmid: 19509116
references.citation: N Engl J Med. 2013 Mar 7;368(10):893-903
references.pmid: 23390923
references.citation: AJNR Am J Neuroradiol. 2013 Oct;34(10):1908-13
references.pmid: 23620073
references.citation: AJNR Am J Neuroradiol. 2011 Oct;32(9):1640-5
references.pmid: 21799045