Imaging of the pial arterial vasculature of the human brain in vivo using high-resolution 7T time-of-flight angiography

Our latest work is out in eLife: https://elifesciences.org/articles/71186

We show how small pial arteries can be targeted effectively with high-resolution in vivo MR imaging. The data is openly available (https://doi.org/10.17605/OSF.IO/NR6GC) and may be used for building models of brain physiology.

The pial arterial vasculature of the human brain is the only blood supply to the neocortex, but quantitative data on the morphology and topology of these mesoscopic arteries (diameter 50–300 µm) remains scarce.

Here, we provide a theoretical framework that outlines how TOF-MRA can visualize small pial arteries in vivo, by employing extremely small voxels at the size of individual vessels.

We then provide evidence for this theory by imaging the pial arteries at 140 µm isotropic resolution using a 7 Tesla (T) magnetic resonance imaging (MRI) scanner and prospective motion correction, and show that pial arteries one voxel width in diameter can be detected.

We conclude that imaging pial arteries is not limited by slow blood flow, but instead by achievable image resolution. This study represents the first targeted, comprehensive account of imaging pial arteries in vivo in the human brain.

This ultra-high-resolution angiography will enable the characterization of pial vascular anatomy across the brain to investigate patterns of blood supply and relationships between vascular and functional architecture.