1. A method for performing patient specific analysis of disease relevant changes of a disease in an anatomical structure of interest, the method comprising: acquiring image data corresponding to the anatomical structure of interest; identifying at least one healthy tissue region in the anatomical structure of interest based on attenuation properties of tissue in the anatomical structure of interest; building a patient specific healthy tissue model based on one or more statistical parameters associated with pixels in the identified healthy tissue region for a given patient; determining a percentage of the anatomical structure that is encompassed by a diseased tissue region using the patient specific healthy tissue model; applying a segmenting process to the image data to determine the percentage of the anatomical structure that is encompassed by the diseased tissue region, wherein the segmenting process identifies the percentage of the anatomical structure encompassed by the diseased tissue region by classifying each pixel within the anatomical structure into either a healthy tissue region or a diseased tissue region within the anatomical structure; determining the amount or spatial distribution or a combination thereof of tissue volume variation due to the disease in the anatomical structure based on the percentage of the anatomical structure encompassed by the diseased tissue region and an estimated original amount of tissue; and displaying the percentage of the anatomical structure encompassed by the diseased tissue region.