1. A system for medical image processing, the system comprising: a data storage device storing instructions for medical image processing; and a processor configured to execute the instructions to perform a method including: receiving one or more non-invasively produced images of at least a blood vessel of a patient; segmenting the images to identify an ischemic region of interest of the blood vessel and generating a three-dimensional geometric model of the identified ischemic region of interest of the blood vessel; identifying a vessel region of interest in the identified ischemic region of interest; identifying a stenosis in the vessel region of interest based on a pressure index computed using a first simulation of blood flow through the geometric model of the blood vessel; determining a connection position to connect a bypass vessel that diverts blood flow around the identified stenosis, wherein the connection position is determined using a subsequent simulation of blood flow; and displaying the determined connection position on a display.