Enlarged Perivascular Spaces in the Basal Ganglia Surround Arteries, not Veins

Fluid-filled perivascular spaces (PVS) surround brain vessels. Their enlargement is a common hallmark of cerebral small vessel disease (CSVD) and has been related to impaired clearance of toxic proteins from the brain. It is unclear whether PVS enlarge around arteries, veins, or both. Combining ultra-high resolution 7T MRI angiography, venography and histology, we show that in healthy controls and patients with CSVD, PVS enlarge around arteries more than veins within the basal ganglia. A better understanding of the anatomy and distribution of enlarged PVS can contribute to the understanding of perivascular clearance and disease mechanisms.