“…In small animals, flow meters, [13][14][15] lase specs, 16 and microspheres, 17,18 have been used to evaluate PV flow, but these modalities are too invasive to be used repeatedly, and the flow velocity data they provide is insufficiently detailed. Alternatively, several studies have used MRI to evaluate PV flow in humans and rodents, 19,20 concluding that MRI offers several advantages over the aforementioned modalities, including noninvasiveness, objectivity as opposed to examiner dependence, and a three-dimensional scanning area. Yet even 2D cine PC-MRI, the standard MRI method to date, only detects flow velocity perpendicular to a single cross-sectional scanning plane, and so does not enable flow assessment of the entire PV tree.…”