Statistical mapping of effects of middle cerebral artery occlusion (MCAO) on blood flow and oxygen consumption in porcine brain

The volume of cerebral tissue perturbed in experimental models of middle cerebral artery occlusion (MCAO) can be highly variable. Thus, the territories of reduced cerebral blood flow (CBF) or oxygen consumption (CMRO2) following MCAO might properly be defined using statistical parametric mapping within a population. In order to establish such a method, we mapped CBF and CMRO2 in 18 pigs with acute MCAO. Parametric maps were flipped about the axis of symmetry, and CBF and CMRO2 in the infarcted hemisphere were calculated as percentages of the magnitudes in mirror-image pixels. There were log-linear relationships between the volumes of affected tissue and the percentages of normal CFB or CMRO2. This graphical analysis showed that the volume of the core deficit was smaller for CBF that for CMRO2, but expanded more rapidly with decreasing CBF deficit than did the corresponding volumes of reduced CMRO2. Thus, acute changes in CBF and CMRO2 following MCAO in the pig can be defined as probabilistic volumes.