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Investigating potentially salvageable penumbra tissue in an in vivo model of transient ischemic stroke using sodium, diffusion, and perfusion magnetic resonance imaging

Wetterling, Friedrich LU ; Chatzikonstantinou, Eva; Tritschler, Laurent; Meairs, Stephen; Fatar, Marc; Schad, Lothar R. and Ansar, Saema LU (2016) In BMC Neuroscience 17(1).
Abstract

Background: Diffusion magnetic resonance imaging (MRI) is the current-state-of-the-art technique to clinically investigate acute (0-24 h) ischemic stroke tissue. However, reduced apparent diffusion coefficient (ADC)-considered a marker of tissue damage-was observed to reverse spontaneously during the subacute stroke phase (24-72 h) which means that low ADC cannot be used to reflect the damaged tissue after 24 h in experimental and clinical studies. One reason for the change in ADC is that ADC values drop with cytotoxic edema (acute phase) and rise when vasogenic edema begins (subacute phase). Recently, combined 1H- and 23Na-MRI was proposed as a more accurate approach to improve delineation between reversible... (More)

Background: Diffusion magnetic resonance imaging (MRI) is the current-state-of-the-art technique to clinically investigate acute (0-24 h) ischemic stroke tissue. However, reduced apparent diffusion coefficient (ADC)-considered a marker of tissue damage-was observed to reverse spontaneously during the subacute stroke phase (24-72 h) which means that low ADC cannot be used to reflect the damaged tissue after 24 h in experimental and clinical studies. One reason for the change in ADC is that ADC values drop with cytotoxic edema (acute phase) and rise when vasogenic edema begins (subacute phase). Recently, combined 1H- and 23Na-MRI was proposed as a more accurate approach to improve delineation between reversible (penumbra) and irreversible ischemic injury (core). The aim of this study was to investigate the effects of reperfusion on the ADC and the sodium MRI signal after experimental ischemic stroke in rats in well-defined areas of different viability levels of the cerebral lesion, i.e. core and penumbra as defined via perfusion and histology. Transient middle cerebral artery occlusion was induced in male rats by using the intraluminal filament technique. MRI sodium, perfusion and diffusion measurement was recorded before reperfusion, shortly after reperfusion and 24 h after reperfusion. The animals were reperfused after 90 min of ischemia. Results: Sodium signal in core did not change before reperfusion, increased after reperfusion while sodium signal in penumbra was significantly reduced before reperfusion, but showed no changes after reperfusion compared to control. The ADC was significantly decreased in core tissue at all three time points compared to contralateral side. This decrease recovered above commonly applied viability thresholds in the core after 24 h. Conclusions: Reduced sodium-MRI signal in conjunction with reduced ADC can serve as a viability marker for penumbra detection and complement hydrogen diffusion- and perfusion-MRI in order to facilitate time-independent assessment of tissue fate and cellular bioenergetics failure in stroke patients.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Diffusion, Magnetic resonance imaging, Perfusion, Sodium, Stroke
in
BMC Neuroscience
volume
17
issue
1
publisher
BioMed Central
external identifiers
  • scopus:85002768196
  • wos:000390829500001
ISSN
1471-2202
DOI
10.1186/s12868-016-0316-1
language
English
LU publication?
yes
id
cecfe2e4-a05b-4f38-810d-7743130b5a18
date added to LUP
2016-12-23 10:23:39
date last changed
2017-10-22 05:24:11
@article{cecfe2e4-a05b-4f38-810d-7743130b5a18,
  abstract     = {<p>Background: Diffusion magnetic resonance imaging (MRI) is the current-state-of-the-art technique to clinically investigate acute (0-24 h) ischemic stroke tissue. However, reduced apparent diffusion coefficient (ADC)-considered a marker of tissue damage-was observed to reverse spontaneously during the subacute stroke phase (24-72 h) which means that low ADC cannot be used to reflect the damaged tissue after 24 h in experimental and clinical studies. One reason for the change in ADC is that ADC values drop with cytotoxic edema (acute phase) and rise when vasogenic edema begins (subacute phase). Recently, combined <sup>1</sup>H- and <sup>23</sup>Na-MRI was proposed as a more accurate approach to improve delineation between reversible (penumbra) and irreversible ischemic injury (core). The aim of this study was to investigate the effects of reperfusion on the ADC and the sodium MRI signal after experimental ischemic stroke in rats in well-defined areas of different viability levels of the cerebral lesion, i.e. core and penumbra as defined via perfusion and histology. Transient middle cerebral artery occlusion was induced in male rats by using the intraluminal filament technique. MRI sodium, perfusion and diffusion measurement was recorded before reperfusion, shortly after reperfusion and 24 h after reperfusion. The animals were reperfused after 90 min of ischemia. Results: Sodium signal in core did not change before reperfusion, increased after reperfusion while sodium signal in penumbra was significantly reduced before reperfusion, but showed no changes after reperfusion compared to control. The ADC was significantly decreased in core tissue at all three time points compared to contralateral side. This decrease recovered above commonly applied viability thresholds in the core after 24 h. Conclusions: Reduced sodium-MRI signal in conjunction with reduced ADC can serve as a viability marker for penumbra detection and complement hydrogen diffusion- and perfusion-MRI in order to facilitate time-independent assessment of tissue fate and cellular bioenergetics failure in stroke patients.</p>},
  articleno    = {82},
  author       = {Wetterling, Friedrich and Chatzikonstantinou, Eva and Tritschler, Laurent and Meairs, Stephen and Fatar, Marc and Schad, Lothar R. and Ansar, Saema},
  issn         = {1471-2202},
  keyword      = {Diffusion,Magnetic resonance imaging,Perfusion,Sodium,Stroke},
  language     = {eng},
  month        = {12},
  number       = {1},
  publisher    = {BioMed Central},
  series       = {BMC Neuroscience},
  title        = {Investigating potentially salvageable penumbra tissue in an in vivo model of transient ischemic stroke using sodium, diffusion, and perfusion magnetic resonance imaging},
  url          = {http://dx.doi.org/10.1186/s12868-016-0316-1},
  volume       = {17},
  year         = {2016},
}