Non-destructive 3D Microtomography of Cerebral Angioarchitecture Changes Following Ischemic Stroke in Rats Using Synchrotron Radiation

Abstract

A better understanding of functional changes in the cerebral microvasculature following ischemic injury is essential to elucidate the pathogenesis of stroke. Up to now, the simultaneous depiction and stereological analysis of 3D micro-architectural changes of brain vasculature with network disorders remains a technical challenge. We aimed to explore the three dimensional (3D) microstructural changes of microvasculature in the rat brain on 4, 6 hours, 3 and 18 days post-ischemia using synchrotron radiation micro-computed tomography (SRμCT) with a per pixel size of 5.2 μm. The plasticity of angioarchitecture was distinctly visualized. Quantitative assessments of time-related trends after focal ischemia, including number of branches, number of nodes, and frequency distribution of vessel diameter, reached a peak at 6 h and significantly decreased at 3 days and initiated to form cavities. The detected pathological changes were also proven by histological tests. We depicted a novel methodology for the 3D analysis of vascular repair in ischemic injury, both qualitatively and quantitatively. Cerebral angioarchitecture sustained 3D remodeling and modification during the healing process. The results might provide a deeper insight into the compensatory mechanisms of microvasculature after injury, suggesting that SRμCT is able to provide a potential new platform for deepening imaging pathological changes in complicated angioarchitecture and evaluating potential therapeutic targets for stroke.

SRμCT Reveals 3D Microstructural Alterations of the Vascular and Neuronal Network in a Rat Model of Chronic Compressive Thoracic Spinal Cord Injury

“…Depending on the magnitude of X-ray absorption by the neurons and vasculature, differences in the gray values among tissues were determined, and microstructures of interest with a length of 1 cm for vascular analysis and a length of 0.5 mm for neuronal network analysis were extracted from the 3D models by segmentation. The 3D-rendered data were analyzed with the Image Pro Analyzer 3D (version 7.0, Media Cybernetics, Inc., Bethesda, MD, USA) to obtain quantitative data for the neuronal and vascular structures, as previously described [30,31], including the vascular volume fraction, vessel number, vessel thickness, vessel bifurcation density, vessel segment density, vessel segment length of the spinal cord, central sulcal artery (CSA) angle, soma volume fraction, soma density, and neurite length.…”

Illuminating the Brain With X-Rays: Contributions and Future Perspectives of High-Resolution Microtomography to Neuroscience

“…The subsequent reconstruction of a 3D model for the vessels and vacuoles network found that the distribution of vacuoles is not uniform and the more severe the state of the disease, the greater the vasodilatation. Finally, a study by Luo et al (2019) analyzed brain samples from mice subjected to ischemia and described a new methodology that allowed the 3D analysis of the vascular repair in the ischemic lesion, both qualitatively and quantitatively, so that the morphology of the micro vessels could be visualized after the reconstruction of the vascular skeleton ( Luo et al, 2019 ).…”

Reducing the Amount of M1 Microglia by Inhibiting CXCR4 and iNOS Exerts Neuroprotection in a Rat Model of Subarachnoid Hemorrhage

“…As a previous study [24] described, 10% chloral hydrate (0.4 ml/kg) was injected intraperitoneally to anesthetized those rats and x all the rats in the stereotaxic apparatus. The experimental SAH model consisted of a needle with a rounded tip and a side hole stereotaxic insertion into the prechiasmatic cistern.…”