title: MRI detection of early blood-brain barrier disruption: parenchymal enhancement predicts focal hemorrhagic transformation after thrombolysis.
abstract: OBJECTIVE
  Blood-brain barrier disruption may be a predictor of hemorrhagic transformation (HT) in ischemic stroke. We hypothesize that parenchymal enhancement (PE) on postcontrast T1-weighted MRI predicts and localizes subsequent HT.
  
  
  METHODS
  In a prospective study, 33 tPA-treated stroke patients were imaged by perfusion-weighted imaging, T1 and FLAIR before thrombolytic therapy and after 2 and 24 hours.
  
  
  RESULTS
  Postcontrast T1 PE was found in 5 of 32 patients (16%) 2 hours post-thrombolysis. All 5 patients subsequently showed HT compared to 11 of 26 patients without PE (P=0.043, specificity 100%, sensitivity 31%), with exact anatomic colocation of PE and HT. Enhancement of cerebrospinal fluid on FLAIR was found in 4 other patients, 1 of which developed HT. Local reperfusion was found in 4 of 5 patients with PE, whereas reperfusion was found in all cases of cerebrospinal fluid hyperintensity.
  
  
  CONCLUSIONS
  PE detected 2 hours after thrombolytic therapy predicts HT with high specificity. Contrast-enhanced MRI may provide a tool for studying HT and targeting future therapies to reduce risk of hemorrhagic complications.
authors.forename: Niels
authors.initials: N
authors.lastname: Hjort
authors.forename: Ona
authors.initials: O
authors.lastname: Wu
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Ashkanian
authors.forename: Christine
authors.initials: C
authors.lastname: Sølling
authors.forename: Kim
authors.initials: K
authors.lastname: Mouridsen
authors.forename: Søren
authors.initials: S
authors.lastname: Christensen
authors.forename: Carsten
authors.initials: C
authors.lastname: Gyldensted
authors.forename: Grethe
authors.initials: G
authors.lastname: Andersen
authors.forename: Leif
authors.initials: L
authors.lastname: Østergaard
mesh_terms: D000368:Aged; D001812:Blood-Brain Barrier; D002545:Brain Ischemia / Q000150:complications*; D002543:Cerebral Hemorrhage / Q000139:chemically induced*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D015912:Thrombolytic Therapy / Q000009:adverse effects*