Fluoroscopic particle tracking in a model aneurysm using traceable droplets

Conventional angiographic techniques are limited by their ability to provide only streaklines of flow patterns and does not render quantitative analysis of the flow. In this study we examined the possibility of obtaining quantitative flow information by injecting insoluble droplets of contrast material into an aneurysm phantom. The phantom was connected to a recirculating flow apparatus. Pulsatile flow was employed with a working fluid mixture of 1:1 water glycerine solution. The flow patterns in the phantom were investigated using a fluoroscopic unit. Calibrated droplets of insoluble contrast media, Ethiodol, were injected at different locations in the channel carrying the aneurysm. Droplet paths were recorded at a rate of 30 frames per second. Peak flow velocity of the droplets was determined from displacement of the droplets between successive video frames and the known geometry of the model. The results of the video velocity analysis compared reasonably well with velocity values calculated from the measured flow rate by an electromagnetic flow meter.