Intra-procedural DSA series are transferred to a research workstation to generate the color-coded images and make quantitative measurements. Region of interest (ROI) measurements are performed equivalently in the endoleak and the aorta after the image generation. There are three kinds of ROIs including a small circle area with the shortest time to peak, a circle area with peak contrast intensity and the whole endoleak area. The ROI and a reference at the same latitude within the aorta are selected to undergo measurement which reflected the endoleak hemodynamics of the endoleak to the utmost extent.