In Vivo Vessel Size Imaging Using 9.4 T MRI: Histopathological Validation

Motivation: Vessel size imaging (VSI) of contrast-agent based MRI can be used to measure the structural and topological heterogeneity of microvascular networks. Goal(s): The aim of this study is to investigate the feasibility and effectiveness of vessel size imaging on 9.4T MRI Approach: We implanted C6 gliomas in situ in Wistar rats and quantified VSI at 9.4T MRI. Following staining with the endothelial cell marker CD31, we assessed the correlation between VSI-MRI measurements and vessel radius using immunohistochemistry. Results: The elevated VSI and CBV values in the tumor region align with the increased vascular proliferation and vessel enlargement observed in histological analysis. Impact: Comparing VSI-MRI with histopathological validation provides crucial insights into vascular structure in tumors, enhancing non-invasive characterization accuracy. This method could improve tumor diagnosis, monitoring, and treatment planning by reliably correlating imaging results with microscopic vascular architecture.