A method and system for the automated detection and analysis of pulmonary nodules in computed tomographic scans which uses data from computed tomography (CT) scans taken at different times is described. The method and system includes processing CT lung images to identify structures in the images for one patient in each of a plurality of different studies and then relating the plurality of CT lung images taken from the patient in one CT study with a plurality of CT lung images taken from the same patient in at least one other different study to detect changes in structures within the CT images.