Akash Pravin Kansagra MS, Presenter: Nothing to Disclose

Eric C. Wong MD, PhD, Abstract Co-Author: Nothing to Disclose

Vessel encoded arterial spin labeling (ASL) MRI allows for quantitative, non-invasive imaging of perfusion territories of arteries supplying the brain. Here, we demonstrate the ability of vessel encoded ASL to separately image the perfusion territories of the left and right vertebral arteries (VA).

Vessel encoded ASL uses a pseudo-continuous ASL sequence to invert arterial water as it traverses a spatially-encoded tagging plane. The spatial encoding allows simultaneous application of unique tags to multiple vessels. Tagging of vessels is performed in the upper neck, well below the vertebrobasilar junction. With this technique, we can distinguish left carotid, right carotid, left vertebral, and right vertebral artery perfusion on nine 8 mm thick, 64-by-64 slices with 22 cm FOV using two 4:39 minute scans.

Vessel encoded ASL enables quantitative imaging of perfusion territories of the VAs. Data in healthy subjects indicates that the combined VA perfusion territory is consistent with the known territory of the basilar artery (BA). These same data indicate substantial asymmetry in the supply of vertebral blood to the brain. In addition to differences in the total perfusion through each VA, there are varying degrees of vertebral mixing in the BA which result in inhomogeneous VA perfusion territories. For instance, in one subject, we found that the right VA supplies only the posteromedial portion of the cerebellum, with the remainder of the BA territory supplied by the left VA. These patterns of VA perfusion appear to vary from person to person.

Vessel encoded ASL can non-invasively image VA perfusion territories and reveal asymmetries in these territories due to incomplete mixing of vertebral blood in the BA. Knowledge of these territories in each patient is likely to be of clinical value.

Vessel encoded ASL can separately image left and right vertebral artery perfusion territories and may be useful in managing stroke, stenosis, and chemotherapy.

Kansagra, A, Wong, E, Separation of Vertebral Artery Perfusion Territories Using Vessel Encoded Arterial Spin Labeling.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5011652.html