title: Measuring elevated microvascular permeability and predicting hemorrhagic transformation in acute ischemic stroke using first-pass dynamic perfusion CT imaging.
abstract: OBJECTIVE
  Hemorrhagic transformation (HT) can be a devastating complication of acute ischemic stroke (AIS). The purpose of this study was to determine whether increased microvascular permeability (PS) of the blood-brain barrier was detected in early AIS by using first-pass dynamic perfusion CT (PCT) and whether PS was significantly higher in infarcts destined for HT.
  
  
  METHODS
  Fifty patients with AIS less than 3 hours old and evaluated by PCT were included. PS color maps were retrospectively generated from PCT data using the Patlak model. One reader analyzed each PS map by drawing 4 circular 10-mm regions of interest on any focal abnormality. The mean of these 4 regions of interest represented the PS of the infarct (PSinfarct). The mean of 4 mirror regions of interest on the nonischemic contralateral hemisphere was also obtained (PScontrol). PSinfarct and PScontrol were compared by using an exact Wilcoxon test. PSinfarct for infarcts that developed HT on follow-up (PSHT) was compared with all of the others (PSNo-HT) using an exact Mann-Whitney test.
  
  
  RESULTS
  Forty-four infarcts (88%) showed focal PS elevation in the region of infarct. In units of milliliters per 100 milliliters per minute, PSinfarct ranged from 0 to 13 (mean: 3.5+/-3.1) versus PScontrol of 0-0.8 (mean: 0.28+/-0.27; P<.0001). Six infarcts (12%) developed HT, all of which were within the region of PS elevation. PSHT ranged from 5.2 to 13 (mean: 9.8+/-2.9) versus PSNo-HT of 0-5.9 (mean: 2.7+/-2.0; P<.0001). Eighteen infarcts (36%) were treated with recombinant tissue plasminogen activator (rtPA). A significant difference between PSHT and PSNo-HT persisted irrespective of rtPA treatment.
  
  
  CONCLUSIONS
  Elevated permeability was detectable in AIS by using first-pass PCT and it predicted subsequent HT.
authors: Department of Radiology, New York University Medical Center, New York, NY 10029, USA.
authors: K
authors: K
authors: Lin
authors: K S
authors: KS
authors: Kazmi
authors: M
authors: M
authors: Law
authors: J
authors: J
authors: Babb
authors: N
authors: N
authors: Peccerelli
authors: B K
authors: BK
authors: Pramanik
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000150:complications / Q000000981:diagnostic imaging*; D002199:Capillary Permeability; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000000981:diagnostic imaging*; D008875:Middle Aged; D010477:Perfusion / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D020521:Stroke / Q000150:complications / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*
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