Co-registration of radiographic and pathologic infarct territory in a non-human primate model of stroke

Objectives: Infarct volume correlation using magnetic resonance imaging (MRI) and pathology specimens enables exact tissue localization of cerebral injury following experimental stroke. We describe a protocol that enables co-registration of radiographic signal change and histologic ischemia in a non-human primate model of stroke. Methods: One male baboon underwent left middle cerebral artery territory occlusion/ reperfusion. MRI [5 mm axial T2 weighted (T2W) slices] was carried out 9 days post-ischemia after which the animal was killed. Immediately post-mortem, the whole brain was perfused and fixed in paraformaldehyde and sliced into 5 mm axial sections that corresponded to those demonstrated on MRI. Slices (40 μm) were obtained from each section and were then stained using Luxol hematoxylin and eosin. Results: The relative area of hyperintensity demonstrated on T2W MRI approximates, in size and location, the region of infarct on gross pathology. This was confirmed microscopically. Discussion: With the use of advanced imaging modalities, this co-registration technique affords the capacity to differentiate ischemic core, penumbra, and uninjured cortex following experimental stroke. Such a precise delineation enables immunohistochemical analysis of a wide variety of substrates in each of the aforementioned regions.