Stroke penumbra defined by an MRI-based oxygen challenge technique: 2. Validation based on the consequences of reperfusion

Robertson, C. A., McCabe, C. , Gallagher, L., Lopez Gonzalez, M. d., Holmes, W. M. , Condon, B., Muir, K. W. , Santosh, C. and Macrae, I. M. (2011) Stroke penumbra defined by an MRI-based oxygen challenge technique: 2. Validation based on the consequences of reperfusion. Journal of Cerebral Blood Flow and Metabolism, 31(8), pp. 1788-1798. (doi:10.1038/jcbfm.2011.67)

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Magnetic resonance imaging (MRI) with oxygen challenge (T2* OC) uses oxygen as a metabolic biotracer to define penumbral tissue based on CMRO2 and oxygen extraction fraction. Penumbra displays a greater T2* signal change during OC than surrounding tissue. Since timely restoration of cerebral blood flow (CBF) should salvage penumbra, T2* OC was tested by examining the consequences of reperfusion on T2* OC-defined penumbra. Transient ischemia (109±20 minutes) was induced in male Sprague-Dawley rats (n=8). Penumbra was identified on T2*-weighted MRI during OC. Ischemia and ischemic injury were identified on CBF and apparent diffusion coefficient maps, respectively. Reperfusion was induced and scans repeated. T2 for final infarct and T2* OC were run on day 7. T2* signal increase to OC was 3.4% in contralateral cortex and caudate nucleus and was unaffected by reperfusion. In OC-defined penumbra, T2* signal increased by 8.4%±4.1% during ischemia and returned to 3.25%±0.8% following reperfusion. Ischemic core T2* signal increase was 0.39%±0.47% during ischemia and 0.84%±1.8% on reperfusion. Penumbral CBF increased from 41.94±13 to 116.5±25 mL per 100 g per minute on reperfusion. On day 7, OC-defined penumbra gave a normal OC response and was located outside the infarct. T2* OC-defined penumbra recovered when CBF was restored, providing further validation of the utility of T2* OC for acute stroke management.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Gallagher, Mrs Lindsay and Macrae, Professor I Mhairi and Condon, Professor Barrie and Santosh, Dr Celestine and Holmes, Dr William and Muir, Professor Keith and Lopez Gonzalez, Dr Rosario and McCabe, Dr Chris
Authors: Robertson, C. A., McCabe, C., Gallagher, L., Lopez Gonzalez, M. d., Holmes, W. M., Condon, B., Muir, K. W., Santosh, C., and Macrae, I. M.
Subjects:R Medicine > RC Internal medicine > RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry
College/School:College of Medical Veterinary and Life Sciences > Institute of Neuroscience and Psychology
Journal Name:Journal of Cerebral Blood Flow and Metabolism
Publisher:Nature Publishing Group
ISSN (Online):1559-7016
Published Online:11 May 2011
Copyright Holders:Copyright © 2011 International Society for Cerebral Blood Flow and Metabolism
First Published:First published in Journal of Cerebral Blood Flow and Metabolism 2011
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher
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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
455001Imaging the ischaemic penumbra using BOLD MRI with oxygen challenge as a biotracerI MacraeMedical Research Council (MRC)G0700439Institute of Neuroscience and Psychology