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Imaging the physiological evolution of the ischemic penumbra in acute ischemic stroke

Leigh, Richard; Knutsson, Linda LU ; Zhou, Jinyuan and van Zijl, Peter Cm (2017) In Journal of Cerebral Blood Flow and Metabolism
Abstract

We review the hemodynamic, metabolic and cellular parameters affected during early ischemia and their changes as a function of approximate cerebral blood flow ( CBF) thresholds. These parameters underlie the current practical definition of an ischemic penumbra, namely metabolically affected but still viable brain tissue. Such tissue is at risk of infarction under continuing conditions of reduced CBF, but can be rescued through timely intervention. This definition will be useful in clinical diagnosis only if imaging techniques exist that can rapidly, and with sufficient accuracy, visualize the existence of a mismatch between such a metabolically affected area and regions that have suffered cell depolarization. Unfortunately, clinical... (More)

We review the hemodynamic, metabolic and cellular parameters affected during early ischemia and their changes as a function of approximate cerebral blood flow ( CBF) thresholds. These parameters underlie the current practical definition of an ischemic penumbra, namely metabolically affected but still viable brain tissue. Such tissue is at risk of infarction under continuing conditions of reduced CBF, but can be rescued through timely intervention. This definition will be useful in clinical diagnosis only if imaging techniques exist that can rapidly, and with sufficient accuracy, visualize the existence of a mismatch between such a metabolically affected area and regions that have suffered cell depolarization. Unfortunately, clinical data show that defining the outer boundary of the penumbra based solely on perfusion-related thresholds may not be sufficiently accurate. Also, thresholds for CBF and cerebral blood volume ( CBV) differ for white and gray matter and evolve with time for both inner and outer penumbral boundaries. As such, practical penumbral imaging would involve parameters in which the physiology is immediately displayed in a manner independent of baseline CBF or CBF threshold, namely pH, oxygen extraction fraction ( OEF), diffusion constant and mean transit time ( MTT). Suitable imaging technologies will need to meet this requirement in a 10-20 min exam.

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Contribution to journal
publication status
epub
subject
in
Journal of Cerebral Blood Flow and Metabolism
publisher
Nature Publishing Group
external identifiers
  • scopus:85027565310
ISSN
1559-7016
DOI
10.1177/0271678X17700913
language
English
LU publication?
yes
id
50f43fbe-89d8-4b4b-b1d8-4bc21eb27813
date added to LUP
2017-11-23 13:18:47
date last changed
2018-10-03 11:02:22
@article{50f43fbe-89d8-4b4b-b1d8-4bc21eb27813,
  abstract     = {<p>We review the hemodynamic, metabolic and cellular parameters affected during early ischemia and their changes as a function of approximate cerebral blood flow ( CBF) thresholds. These parameters underlie the current practical definition of an ischemic penumbra, namely metabolically affected but still viable brain tissue. Such tissue is at risk of infarction under continuing conditions of reduced CBF, but can be rescued through timely intervention. This definition will be useful in clinical diagnosis only if imaging techniques exist that can rapidly, and with sufficient accuracy, visualize the existence of a mismatch between such a metabolically affected area and regions that have suffered cell depolarization. Unfortunately, clinical data show that defining the outer boundary of the penumbra based solely on perfusion-related thresholds may not be sufficiently accurate. Also, thresholds for CBF and cerebral blood volume ( CBV) differ for white and gray matter and evolve with time for both inner and outer penumbral boundaries. As such, practical penumbral imaging would involve parameters in which the physiology is immediately displayed in a manner independent of baseline CBF or CBF threshold, namely pH, oxygen extraction fraction ( OEF), diffusion constant and mean transit time ( MTT). Suitable imaging technologies will need to meet this requirement in a 10-20 min exam.</p>},
  author       = {Leigh, Richard and Knutsson, Linda and Zhou, Jinyuan and van Zijl, Peter Cm},
  issn         = {1559-7016},
  language     = {eng},
  publisher    = {Nature Publishing Group},
  series       = {Journal of Cerebral Blood Flow and Metabolism},
  title        = {Imaging the physiological evolution of the ischemic penumbra in acute ischemic stroke},
  url          = {http://dx.doi.org/10.1177/0271678X17700913},
  year         = {2017},
}