1. An image processing system, the system comprising: a computer, wherein the computer receives a plurality of image scans acquired over time, the image scans being of an area of interest of a patient to which a contrast agent was administered; wherein the computer uses registration logic to register the image scans to a common coordinate system to compensate for artifacts in the image scans; wherein the computer uses selection logic to process the image scans and automatically select locations at which observed reference information is compared to modeled reference information to obtain plausible reference information; wherein the observed reference information includes a time-concentration curve representing an observed curve and the modeled reference information includes a time-concentration curve representing a model curve.