1. A method of assessing stenosis severity for a patient, comprising: obtaining patient information relevant to assessing stenosis severity, including anatomical imaging data of the patient; identifying the existence of any lesions of concern in a vessel of the Patient that have an irregular shape from the anatomical imaging data; inputting the anatomical imaging data of the patient into a computer system; utilizing a processor associated with the computer system and task specific software to generate a three dimensional model from the patient anatomical imaging data of at least one lesion of concern within the vessel, wherein the generated three dimensional model includes a vessel inlet, the at least one lesion of concern, and at least one vessel outlet; utilizing the processor and task specific software to create a series of comparative two dimensional lesion specific models having conditions that correspond to the three dimensional model, wherein each of the series of comparative two dimensional models represents a vessel having one or more regular shaped lesions within the vessel and wherein each of the two dimensional lesion specific models includes differently configured lesions each representing a different known level of stenosis severity; mapping the three dimensional model to one two dimensional model of the series of comparative two dimensional models; deriving a quantitative measure of stenosis severity of the patient's coronary artery disease based on the mapped two dimensional model.