title: Utility of perfusion-weighted CT imaging in acute middle cerebral artery stroke treated with intra-arterial thrombolysis: prediction of final infarct volume and clinical outcome.
abstract: OBJECTIVE
  The goal of this study was to evaluate the utility of perfusion-weighted CT (PWCT) in predicting final infarct volume and clinical outcome in patients with acute middle cerebral artery (MCA) stroke.
  
  
  METHODS
  Twenty-two consecutive patients with MCA stem occlusion who underwent intra-arterial thrombolysis within 6 hours of stroke onset had noncontrast CT and CT angiography with whole-brain PWCT imaging before treatment. Infarct volumes were computed from the initial PWCT and follow-up scans; clinical outcome was measured with the modified Rankin scale.
  
  
  RESULTS
  Initial PWCT lesion volumes correlated significantly with final infarct volume (P=0.0002) and clinical outcome (P=0.01). For the 10 patients with complete recanalization, the relationship between initial and final lesion volume was especially strong (R(2)=0.94, P<0.0001, slope of regression line=0.92). For those without complete recanalization, there was progression of lesion volume on follow-up imaging (R(2)=0.50, P=0.01, slope of regression line=1.61). All patients with either initial PWCT lesion volumes >100 mL or no recanalization had poor outcomes (Rankin scores, 4 to 6). Mean admission NIH Stroke Scale scores and mean lesion volumes in the poor outcome group were significantly different compared with the good or fair outcome (Rankin scores, 0 to 3) group (21+/-4 versus 17+/-5, P=0.05, and 106+/-79 versus 29+/-37 mL, P=0.01). Patients with initial volumes <100 mL and partial or complete recanalization all had good (Rankin scores, 0 to 2) or fair (Rankin score, 3) outcomes.
  
  
  CONCLUSIONS
  Lesion volumes on admission PWCT images approximate final infarct volume for patients with early complete recanalization of MCA stem occlusion. For those without complete recanalization, there is subsequent enlargement of lesion volume on follow-up. Initial PWCT lesion volumes also have predictive value; volumes >100 mL are associated with a poor clinical outcome. In these highly selected patients, initial PWCT lesion volume was a stronger predictor of clinical outcome than was initial NIH Stroke Scale score.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. mlev@partners.org
authors.forename: M H
authors.initials: MH
authors.lastname: Lev
authors.forename: A Z
authors.initials: AZ
authors.lastname: Segal
authors.forename: J
authors.initials: J
authors.lastname: Farkas
authors.forename: S T
authors.initials: ST
authors.lastname: Hossain
authors.forename: C
authors.initials: C
authors.lastname: Putman
authors.forename: G J
authors.initials: GJ
authors.lastname: Hunter
authors.forename: R
authors.initials: R
authors.lastname: Budzik
authors.forename: G J
authors.initials: GJ
authors.lastname: Harris
authors.forename: F S
authors.initials: FS
authors.lastname: Buonanno
authors.forename: M A
authors.initials: MA
authors.lastname: Ezzeddine
authors.forename: Y
authors.initials: Y
authors.lastname: Chang
authors.forename: W J
authors.initials: WJ
authors.lastname: Koroshetz
authors.forename: R G
authors.initials: RG
authors.lastname: Gonzalez
authors.forename: L H
authors.initials: LH
authors.lastname: Schwamm
mesh_terms: D000208:Acute Disease; D000368:Aged; D001783:Blood Flow Velocity; D001810:Blood Volume; D002544:Cerebral Infarction / Q000000981:diagnostic imaging* / Q000209:etiology; D002560:Cerebrovascular Circulation; D003710:Demography; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D011237:Predictive Value of Tests; D011856:Radiographic Image Enhancement; D015912:Thrombolytic Therapy; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome