Visualization and numerical modeling of disturbed flows observed in cineangiography

A set of angiographically acquired images of steady control flows in constricted and unconstricted Plexiglas models and in a human coronary bypass graft was acquired. A set of flow sensitive parametric images was derived from those sequences. The Plexiglas arterial model (phantom) was designed specifically for this study. The parametric images were calculated using the contrast density curves obtained at each pixel in a region of interest in a sequence of angiographically acquired images. The calculated parameters described are a contrast velocity image derived from the slope of the contrast density curve, and an arrival time image of the contrast bolus. A numerical simulation of the contrast flows in the Plexiglas phantoms was also conducted and a synthetic arrival time parametric image was calculated which qualitatively validates the experimental results. This study indicates that parametric images offer an efficient means of identifying regions of recirculation and jetting velocity for the steady flow of Newtonian fluids examined, and may be of diagnostic value in the assessment of human vessels.