1. A system for determining cardiovascular information for a patient, the system comprising: at least one computer system configured to: receive patient-specific image data regarding a geometry of an anatomical structure of the patient, the anatomical structure including at least a portion of at least one coronary artery emanating from an aorta; create a three-dimensional model representing at least the portion of the at least one coronary artery using the received patient-specific image data; determine a blood flow model defining the flow of blood through the three-dimensional model representing at least the portion of the at least one coronary artery; calculate one or more values of a blood flow characteristic within the portion of the at least one coronary artery using by modeling blood flow through the three-dimensional model using the determined blood flow model, where the blood flow model is a function of the three-dimensional model; calculate at least one of: (i) a risk of plaque rupture within the portion of the at least one coronary artery using the modeled blood flow through the three-dimensional model and the one or more calculated values of the blood flow characteristic, and (ii) a risk of perfusion deficit within at least a portion of the anatomical structure of the patient using the modeled blood flow through the three-dimensional model and the one or more calculated values of the blood flow characteristic; and display on the three-dimensional model representing at least the portion of the at least one coronary artery, a visual representation associated with at least one of: (i) the calculated risk of plaque rupture within the portion of the at least one coronary artery, and (ii) the calculated risk of perfusion deficit within at least the portion of the anatomical structure.