19F Imaging of Cerebral Blood Oxygenation in Experimental Middle Cerebral Artery Occlusion: Preliminary Results

Abstract

Fluorine (¹⁹F) nuclear magnetic resonance may be used to image cerebral perfusion in cats receiving perfluorocarbon blood substitutes. ¹⁹F relaxation times in these blood substitutes are dependent on oxygen tension (Po₂) and may be used to calculate and spatially map cerebrovascular Po₂ values in vivo. We have applied this noninvasive method to experimental middle cerebral artery (MCA) occlusion. Following MCA occlusion a perfusion defect is evident in the sylvian region, followed by the appearance of collaterals. Signal from the ipsilateral rete mirabilis is increased. Calculated cortical vascular Po₂ values indicate a relative reduction in oxygenation in the ischaemic hemisphere. Po₂ maps show a perfused hypoxaemic zone adjacent to the perfusion defect. These changes are partly reversed with reperfusion.