In this project, we are developing a clinically viable MRI technique to create a “microvascular print” of the brain’s blood-vessel architecture; establishing quantitative measures of vascular and capillary density of cerebral structures; and evaluating age-related neurovascular changes in people aged 18 through 85.

Abnormalities in the microvascular arterial system, which delivers the oxygen and glucose that fuel the brain’s metabolism, have been increasingly linked to neurologic disorders, including age-related dementia. However, microvascular aging is itself not well understood, and there is an urgent need for in vivo characterization of this process.

Here, we aim to address this need by creating a way to image arterioles and venules with diameters between 50 μm and 100 μm on 3 T and 7 T MRI scanners, using something we call ultra-high resolution USPIO-enhanced MR arteriogram and venogram (USPIO+MRAV). In developing this new method we are building on our prior work in visualizing small veins and arteries via susceptibility weighted imaging and quantitative susceptibility mapping while modifying the arteries’ magnetic susceptibility with ultra-small-superparamagnetic-iron-oxide (USPIO). If successful, ultra-high resolution USPIO+MRAV has the potential to enable new insights into age-related microvascular changes and to become a significant method in the study of cerebral microvasculature.