Objective: To provide evidence of irreversible ischemia in cerebral contusions among patients with severe traumatic brain injuries and to clarify the potential viability of tissue in the pericontusional zone, quantitative regional cerebral blood flow (rCBF) measurements obtained with the xenon-enhanced computed tomographic method were correlated with the areas of contusions, by using image fusion.
Methods: rCBF measurements obtained during the acute phase (mean, 2 d after injury; range, 0-10 d) were statistically correlated with the extent of tissue necrosis identified as focal atrophy on late follow-up computed tomographic scans (mean time after the xenon-enhanced computed tomographic cerebral blood flow investigation, 265 d; range, 30-1047 d).
Results: Seventeen patients exhibited 26 traumatic contusions. All contusions progressed to late focal atrophic areas on the follow-up computed tomographic scans. The rCBF values within the traumatic contusions ranged from 0.5 to 22.0 ml/100 g/min, with a mean of 5.9 +/- 5.9 ml/100 g/min. The contusions exhibited a specific rCBF profile, presenting as a core of severe lethal ischemia surrounded by variable but gradually increasing perfusion with increasing distance from the ischemic core.
Conclusion: The ischemic profile of the contusions, with a pericontusional zone of low rCBF, presents the potential risk of secondary ischemic insults, similar to the risk in the ischemic penumbral zones surrounding areas of acute ischemic stroke.