The arterial vasocorona is part of the spinal cord blood supply and is formed by pial anastomoses between the anterior and posterior spinal arteries on the surface of the spinal cord. It encircles the cord and supplies the peripheral lateral aspect of the spinal cord.
Engorgement of arterial vasocorona may be seen due to collateralised circulation in some pathological scenarios such as moyamoya disease, coarctation of the aorta, etc. This may be seen as enhancing pia on post-contrast MR images 1.