1. A system for determining a perfusion of a myocardial muscle comprising: a data storage device storing instructions for anatomical modeling; and a processor configured to execute the instructions to perform a method including: receiving patient-specific static coronary computed tomography angiography (CCTA) images of a patient's coronary blood vessels and myocardial muscle; generating a three-dimensional model of the patient's blood vessels using the static CCTA images; identifying, from the static CCTA images a selected volume of the patient's myocardial muscle associated with a vessel segment defined by an inflow boundary and an outflow boundary of the three-dimensional model of the patient's blood vessels; calculating an estimate of blood flow through the vessel segment of the three-dimensional model of the patient's blood vessels; determining, using the calculated estimate of blood flow through the vessel segment, a second estimate of the blood flow into the selected volume of the patient's myocardial muscle; and calculating a patient-specific local perfusion of the selected volume of the myocardial muscle using the second estimate of blood flow.