Diffusion tensor MRI for the assessment of cerebral ischemia/reperfusion injury in the penumbra of non-human primate stroke model

Objectives: The purpose of this study is to use diffusion tensor imaging (DTI) parameters to evaluate cerebral ischemia/reperfusion injury in the infarct core (IC) and ischemic penumbra (IP) in a rhesus transient middle cerebral artery occlusion (MCAO) model. Methods: Seven rhesus monkeys were used to construct the MCAO model. The temporal evolution of the relative apparent diffusion coefficient (rADC) and the relative fractional anisotropy (rFA) in the IC area, infarct growth area (IG), and reversible penumbra area (RP) were investigated. Results: The rADC increased in the three areas in the early stage of reperfusion (1 hour after the reperfusion). However, the rate of rADC improvement was significantly slower in IG than in IC and RP. Different temporal evolutions of rFA were observed in the three areas in the following stage of reperfusion (3-24 hours after the reperfusion), which continued to decline in IG but slightly elevated in IC and RP. Discussion: These findings suggest that the evolution of DTI parameters can help in the assessment of cerebral ischemia/reperfusion injury in the penumbra and predict the growth of the infarction area after stroke.