Multi-modal Ultrafast Sonography Microscopy (MUSM) for super-resolution imaging of cerebral vascular dynamics in a mouse model of hypertension induced by Angiotensin-II and L-NAME

Abstract

Hypertension is a major cause of cerebral hemorrhage. Although they are widely used in preclinical studies on cerebral hemorrhage, traditional in vivo cerebrovascular imaging techniques, such as positron emission tomography and magnetic resonance imaging, often fall short in dynamically visualizing cerebral microcirculation blood flow in rodent models. This study leveraged the high spatiotemporal resolution of multimodal ultrafast sonography microscopy (MUSM) to assess cerebrovascular hemodynamics in vivo within hypertensive mice induced by Angiotensin II (Ang II) and Nω-nitro-L-arginine methyl ester (L-NAME). Cerebrovascular hemodynamics were quantified using variations in cerebral vascular density, diameter, velocity, tortuosity, cerebral flow pulsatility, and instant flow direction. Our findings revealed a decrease in cerebral vascular density and perfusion index after blood pressure increased, particularly in the cortex and basal ganglia regions. This study not only provides a comprehensive view of cerebral dynamics in hypertension but also introduces MUSM as a novel tool for in vivo cerebrovascular hemodynamic analysis in preclinical animal research.