title: CT Perfusion in Acute Stroke: "Black Holes" on Time-to-Peak Image Maps Indicate Unsalvageable Brain.
abstract: CT perfusion is becoming important in acute stroke imaging to determine optimal patient-management strategies. The purpose of this study was to examine the predictive value of time-to-peak image maps and, specifically, a phenomenon coined a "black hole" for assessing infarcted brain tissue at the time of scan.
  
  
  
  Acute stroke patients were screened for the presence of black holes and their follow-up imaging (noncontrast CT or MR) was reviewed to assess for infarcted brain tissue.
  
  
  
  Of the 23 patients with signs of acute ischemia on CT perfusion, all had black holes. The black holes corresponded with areas of infarcted brain on follow-up imaging (specificity 100%). Black holes demonstrated significantly lower cerebral blood volumes (P < .001) and cerebral blood flow (P < .001) compared to immediately adjacent tissue.
  
  
  
  Black holes on time-to-peak image maps represent areas of unsalvageable brain.
authors.affiliation: QEII Health Sciences Centre, Victoria General Hospital, NS, B3H 2Y9, Canada.
authors.forename: Ruairi
authors.initials: R
authors.lastname: Meagher
authors.affiliation: Department of Diagnostic Radiology, QEII Health Sciences Centre, NS B3H 3A7, Canada. shivajai1@gmail.com.
authors.forename: Jai Jai Shiva
authors.initials: JJ
authors.lastname: Shankar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging*; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods; D011379:Prognosis; D012680:Sensitivity and Specificity; D020521:Stroke / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: CT; black hole; perfusion; stroke; time to peak