title: Dynamic computed tomography angiography in suspected brain death: a noninvasive biomarker.
abstract: OBJECTIVE
  Neurologic determination of death or brain death is primarily a clinical diagnosis. This must respect all guarantees required by law and should be determined early to avoid unnecessary treatment and allow organ harvesting for transplantation. Ancillary testing is used in situations in which clinical assessment is impossible or confounded by other factors. Our purpose is to determine the utility of dynamic computed tomographic angiography (dCTA) as an ancillary test for diagnosis of brain death.
  
  
  METHODS
  We retrospectively reviewed 13 consecutive patients with suspected brain death in the intensive care unit who had dCTA. Contrast appearance timings recorded from the dCTA data were compared to findings from 15 controls selected from patients who presented with symptoms of acute stroke but showed no stroke in follow-up imaging.
  
  
  RESULTS
  The dCTA allows us to reliably assess cerebral blood flow and to record time of individual cerebral vessels opacification. It also helps us to assess the intracranial flow qualitatively against the flow in extracranial vessels as a reference. We compared the time difference between enhancement of the external and internal carotid arteries and branches. In all patients who were brain dead, internal carotid artery enhancement was delayed, which occurred after external carotid artery branches were opacified.
  
  
  CONCLUSIONS
  In patients with suspected brain death, dCTA reliably demonstrated the lack of cerebral blood flow, with extracranial circulation as an internal reference. Our initial results suggest that inversion of time of contrast appearance between internal carotid artery and external carotid artery branches at the skull base could predict a lack of distal intracranial flow.
authors.affiliation: Division of Neuro-imaging, Department of Medical Imaging, University of Ottawa, The Ottawa Hospital, Ottawa, Ontario, Canada. Electronic address: santanoo@gmail.com.
authors.forename: Santanu
authors.initials: S
authors.lastname: Chakraborty
authors.affiliation: Division of Neuro-imaging, Department of Medical Imaging, University of Ottawa, The Ottawa Hospital, Ottawa, Ontario, Canada.
authors.forename: Reem A
authors.initials: RA
authors.lastname: Adas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D001926:Brain Death / Q000175:diagnosis*; D002533:Cerebral Angiography / Q000379:methods*; D002560:Cerebrovascular Circulation; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D015415:Biomarkers
keywords: Ancillary test; Angiogram; Brain death; Computed tomography; Dynamic computed tomography angiogram