1. A computer-implemented method of identifying and modeling unresolved vessels, and the effects thereof, in image-based patient-specific hemodynamic models, the method comprising: receiving, in an electronic storage medium, one or more patient-specific anatomical models representing at least a vessel of a patient; determining, using a processor, the values and characteristics of one or more patient-specific morphometric features in the one or more patient-specific anatomical models; modifying the one or more patient-specific anatomical models using the determined patient-specific morphometric features; and outputting, one or more of, a modified patient-specific anatomical model or a patient-specific morphometric feature to an electronic storage medium or display.