C. A. Robertson, C. McCabe, L. Gallagher, R. Lopez-Gonzalez Mdel, W. M. Holmes, B. Condon, K. W. Muir, C. Santosh, I. M. Macrae


1559-7016 (Electronic) 0271-678X (Linking)

Publication year



J Cereb Blood Flow Metab

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Author Address

Glasgow Experimental MRI Centre, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.

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Accurate identification of ischemic penumbra will improve stroke patient selection for reperfusion therapies and clinical trials. Current magnetic resonance imaging (MRI) techniques have limitations and lack validation. Oxygen challenge T(2)(*) MRI (T(2)(*) OC) uses oxygen as a biotracer to detect tissue metabolism, with penumbra displaying the greatest T(2)(*) signal change during OC. [(14)C]2-deoxyglucose (2-DG) autoradiography was combined with T(2)(*) OC to determine metabolic status of T(2)(*)-defined penumbra. Permanent middle cerebral artery occlusion was induced in anesthetized male Sprague-Dawley rats (n=6). Ischemic injury and perfusion deficit were determined by diffusion- and perfusion-weighted imaging, respectively. At 147 +/- 32 minutes after stroke, T(2)(*) signal change was measured during a 5-minute 100% OC, immediately followed by 125 muCi/kg 2-DG, intravenously. Magnetic resonance images were coregistered with the corresponding autoradiograms. Regions of interest were located within ischemic core, T(2)(*)-defined penumbra, equivalent contralateral structures, and a region of hyperglycolysis. A T(2)(*) signal increase of 9.22% +/- 3.9% (mean +/- s.d.) was recorded in presumed penumbra, which displayed local cerebral glucose utilization values equivalent to contralateral cortex. T(2)(*) signal change was negligible in ischemic core, 3.2% +/- 0.78% in contralateral regions, and 1.41% +/- 0.62% in hyperglycolytic tissue, located outside OC-defined penumbra and within the diffusion abnormality. The results support the utility of OC-MRI to detect viable penumbral tissue following stroke.