Method for real-time vascular modeling and assessment. Modeling, in some embodiments, comprises receiving a plurality of 2-D angiographic images of a portion of a vasculature of a subject, and processing the images to automatically detect 2-D features, for example, paths along vascular extents, which are projected into 3-D to determine homologous features among blood vessels and construct 3-D vascular extents and determine other vascular characteristics. Assessment, in some embodiments, comprises processing models selectively different from one another to produce one or more vascular indexes which indicate a diagnostic preference, for example, to perform a medical intervention such as a stent implantation. Speed is achieved, for example, by the method being optimized for determining the effects of a medical intervention. In some embodiments, results are produced quickly enough to allow use of the method to perform PCI within the same catheterization used to perform diagnostic imaging.