Toward quantitative virtual angiography: Evaluation with in vitro studies

Medical imaging and computational fluid dynamics (CFD) modeling have been combined to obtain detailed knowledge of local hemodynamics, known to play an important role in cardiovascular diseases. Given the absence of a "gold standard" to measure the blood velocities in vivo, simulation of X-ray angiograms was proposed as a method to indirectly validate the accuracy of image-based CFD analysis. This paper presents a method to simulate the contrast agent transport and the creation of virtual angiograms which takes into account the physics of the contrast agent injection and X-ray transmission. The simulated and acquired angiograms are compared by analyzing the spatial and temporal development of the contrast agent concentration represented by a flow map. This approach was tested with in vitro experiments.