The limitations of angiography in assessing the physiologic significance of stenoses are well recognized, including variation in subtended bed size, lesion eccentricity, and vessel angulation, overlap, and tortuosity. In the coronary bed, the use of fractional flow reserve (FFR) to guide revascularization has been proven to reduce major adverse cardiovascular events, inappropriate stenting, and costs compared with angiography-guided revascularization. To date, however, in the peripheral space, angiography alone has been the standard of care.