title: Association of CT perfusion parameters with hemorrhagic transformation in acute ischemic stroke.
abstract: OBJECTIVE
  Prediction of hemorrhagic transformation in acute ischemic stroke could help determine treatment and prognostication. With increasing numbers of patients with acute ischemic stroke undergoing multimodal CT imaging, we examined whether CT perfusion could predict hemorrhagic transformation in acute ischemic stroke.
  
  
  METHODS
  Patients with acute ischemic stroke who underwent CTP scanning within 12 hours of symptom onset were examined. Patients with and without hemorrhagic transformation were defined as cases and controls, respectively, and were matched as to IV rtPA administration and presentation NIHSS score (± 2). Relative mean transit time, relative CBF, and relative CBV values were calculated from CTP maps and normalized to the contralateral side. Receiver operating characteristic analysis curves were created, and threshold values for significant CTP parameters were obtained to predict hemorrhagic transformation.
  
  
  RESULTS
  Of 83 patients with acute ischemic stroke, 16 developed hemorrhagic transformation (19.28%). By matching, 38 controls were found for only 14 patients with hemorrhagic transformation. Among the matched patients with hemorrhagic transformation, 13 developed hemorrhagic infarction (6 hemorrhagic infarction 1 and 7 hemorrhagic infarction 2) and 1 developed parenchymal hematoma 2. There was no significant difference between cases and controls with respect to age, sex, time to presentation from symptom onset, and comorbidities. Cases had significantly lower median rCBV (8% lower) compared with controls (11% higher) (P = .009; odds ratio, 1.14 for a 0.1-U decrease in rCBV). There was no difference in median total volume of ischemia, rMTT, and rCBF among cases and controls. The area under the receiver operating characteristic was computed to be 0.83 (standard error, 0.08), with a cutoff point for rCBV of 1.09.
  
  
  CONCLUSIONS
  Of the examined CTP parameters, only lower rCBV was found to be significantly associated with a relatively higher chance of hemorrhagic transformation.
authors.affiliation: Departments of Neurosurgery.
authors.forename: A R
authors.initials: AR
authors.lastname: Jain
authors.forename: M
authors.initials: M
authors.lastname: Jain
authors.forename: A R
authors.initials: AR
authors.lastname: Kanthala
authors.forename: D
authors.initials: D
authors.lastname: Damania
authors.forename: L G
authors.initials: LG
authors.lastname: Stead
authors.forename: H Z
authors.initials: HZ
authors.lastname: Wang
authors.forename: B S
authors.initials: BS
authors.lastname: Jahromi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D016022:Case-Control Studies; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000379:methods*