Vascular pathologies such as stenosis cause changes in blood flow patterns and rates in patient vasculature. These changes are difficult to observe using conventional x-ray imaging techniques that typically operate at no more than 30 fps. However, 1000 fps High-Speed Angiography (HSA) provides sufficient temporal resolution to observe flow patterns in patient vasculature. The Actaeon detector from XCounter provides 1000 fps HSA with high spatial resolution (100 μm pixel pitch) enabling observation of detailed blood flow in 3D printed phantoms. To observe the effects of stenosis on flow, three carotid artery phantoms beginning 7.6 cm proximal to the bifurcation of the common carotid and extending 6.9 cm into the internal and external carotids with different degrees of stenosis (0%, 33%, and 66% stenosis) in the internal carotid were printed. Iodine contrast was injected into the phantom proximal to the bifurcation and images were recorded at 1000 fps. Time-density curves were generated for ROIs distal and proximal to the location of the stenosis for both branches of the carotid artery. The curves for the control phantom (no stenosis) showed little difference between the branches of the carotid while the stenotic phantoms showed an increased velocity in the flow of contrast and a lower maximum signal intensity for the stenosed internal carotid. 1000 fps HSA could be used during treatment of vascular pathologies to observe changes in flow patterns following an endovascular treatment.