A Method for Automatic Selection of the Labeling Slabs in Regional Arterial Spin Labeling

INTRODUCTION: Arterial Spin Labeling (ASL) is an established technique for non-invasive measurement of cerebral perfusion. In conventional ASL, blood spins of all large feeding arteries are inverted in a slab perpendicular to them to acquire an image of the entire brain perfusion. To visualize the vascular territories of single arteries rather than the whole vascular tree the method of regional ASL (regASL) is an appropriate choice [1]. By positioning oblique slabs, labeling of selective regions can be accomplished and thus tagging of only specific vessels is feasible. However, performing a separate experiment for every feeding artery is time-consuming since labeling of the left and right internal carotid arteries (lICA and rICA) as well as the posterior circulation (post) must be considered. Cycled regASL [2] offers a possibility to decrease measurement time and increase SNR by tagging two arteries simultaneously for all combinations of lICA, rICA and the posterior circulation. The territory supplied by each single artery can be reconstructed with simple algebraic operations. Careful positioning of the inversion slabs is of great importance. Due to the proximity of the vessels and their intricate shape finding and territorial perfusion. Semi-automatic methods have been proposed [3], but most implementations are still performed manually. Here, we present a completely automatic method for positioning the inversion slabs.