Imaging of Cerebral Angiogenesis in Mice Brain after Ischemic Stroke Based on the X-ray Microscope and Scanning Electron Microscope

Stroke is the second leading disease globally, with high morbidity and mortality among the middle-aged and elderly populations. Stroke prognosis is positively correlated with resistance of vasculature network and angiogenesis. Patients with higher vascular density in the peri-infarct region have higher survival and recovery rates. Previous studies have demonstrated that angiogenesis can restore the blood and oxygen supply of the penumbra. Active angiogenesis relies on endothelial cell (EC) proliferation. But currently, there is a lack of imaging tools to investigate angiogenesis after a stroke at the centimeter scale and sub-micron resolution. In this study, we combine the Xray microscope and scanning electron microscope to achieve this target. By vascular corrosion casting (VCC) of a mouse’s brain, the proposed method reveals the changes of microvasculature below 8 $\mu \mathrm{m}$ diameter and ECs imprinting in penumbra after ischemic stroke (IS). Our method is successfully applied for both aged and young mouse brain samples. We also developed a post-processing procedure to analyze the characteristics of microvasculature and ECs. There are obvious differences between young and aged mouse’s brains. This work established a standardized cross-scale imaging method for ischemic stroke studies.