title: CT angiography-source image hypoattenuation predicts clinical outcome in posterior circulation strokes treated with intra-arterial therapy.
abstract: OBJECTIVE
  The aim of this study was to correlate CT angiography-source image (CTA-SI) parenchymal hypoattenuation with clinical outcome in patients with vertebrobasilar occlusion treated with intra-arterial thrombolysis.
  
  
  METHODS
  In 16 patients with vertebrobasilar occlusion treated with intra-arterial thrombolysis, we graded CTA-SI parenchymal hypoattenuation in the medulla, pons, midbrain, thalamus, cerebellum, occipital lobe, inferior parietal lobe, and medial temporal lobe. The grading scale was: 0, no hypoattenuation; 1, <50% hypoattenuation; and 2, >50% hypoattenuation. On CTA, we assessed clot location and length and collaterals. Outcome was measured with modified Rankin score.
  
  
  RESULTS
  Mean patient age was 68.3 years (range, 47 to 86 years), National Institutes of Health Stroke Scale was 28 (range, 11 to 40), time to CTA was 5.2 hours (range, 0.69 to 15.32), and time from CTA to intra-arterial thrombolysis was 5 hours (range, 2.25 to 10.38 hours). There were 4 basilar, 2 vertebral, and 10 combined occlusions. Eleven patients had near complete, 4 had partial, and one had no recanalization. Independent outcome predictors measured as modified Rankin score at 3 months were CTA-SI pons and midbrain scores(cumulative r=0.81, P<0.001). For outcome dichotomized into death versus survival, the CTA-SI pons score (P=0.0037) was the only independent predictor.
  
  
  CONCLUSIONS
  Hypoattenuation in the pons and midbrain on pretreatment CTA-SI correlates highly with clinical outcome in patients with vertebrobasilar occlusion treated with intra-arterial thrombolysis.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA. pschaefer@partners.org
authors.forename: Pamela W
authors.initials: PW
authors.lastname: Schaefer
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Yoo
authors.forename: Donnie
authors.initials: D
authors.lastname: Bell
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Barak
authors.forename: Javier M
authors.initials: JM
authors.lastname: Romero
authors.forename: Raul G
authors.initials: RG
authors.lastname: Nogueira
authors.forename: Michael H
authors.initials: MH
authors.lastname: Lev
authors.forename: Lee H
authors.initials: LH
authors.lastname: Schwamm
authors.forename: Ramon G
authors.initials: RG
authors.lastname: Gonzalez
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Hirsch
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography / Q000379:methods*; D003627:Data Interpretation, Statistical; D006801:Humans; D007261:Infusions, Intra-Arterial; D008875:Middle Aged; D020521:Stroke / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D015996:Survival Rate; D015912:Thrombolytic Therapy / Q000379:methods*; D016896:Treatment Outcome; D014715:Vertebrobasilar Insufficiency / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*