First In-Vivo demonstration of 1000 fps High Speed X-ray Angiography in quantifying flow in the Carotid Artery of live animal models

High-Speed Angiography (HSAngio) imaging at 1000 fps has previously been used successfully to visualize contrast media (blood) flow in both in vitro and in vivo aneurysm models. In this work, we present, for the first time, the use of HSAngio imaging to visualize flow through the carotid artery in live swine and rabbit models. A 5 French catheter was guided into the right carotid artery of the swine, followed by the injection of iodine contrast using a clinically used media injector at a controlled rate of 2 ml/s. The injection process was captured using HSAngio at a rate of 1000 fps. From these images, detailed velocity maps along the artery were derived using previously published optical flow methods. A similar procedure was also performed to capture HSAngio images of flow in the rabbit model. During the systolic phase, the forward flow of the contrast bolus in the carotid artery of swine and rabbit could be visually tracked as it traversed through the artery, with velocities calculated in the range of 30-50 cm/s. During the diastolic phase, the slower backward flow of the contrast agent within the anatomy was also easily visualized. The results demonstrate the potential of the 1000 fps HSAngio imaging technique in the diagnosis and treatment of Carotid Artery Disease caused by stenosis. The combined high spatial and temporal resolution offered by this technique allows for the derivation of velocity profiles throughout the artery's structure, including regions distal and proximal to stenoses. This information should provide more accurate assessment of the effect of stenosis on blood flow and help determine the most appropriate treatment options, compared to the currently used angiography-based percentage stenosis metric. Further investigations are warranted to expand our understanding of HSAngio's applications for this purpose.