1. A method for measuring calcification in an aorta of a living body, comprising: providing three-dimensional volumetric images of the body, the images comprising a plurality of axial slices, each axial slice comprising voxels indicative of densities of corresponding body structures; automatically locating a vertebral body in an axial slice of the plurality of axial slices; automatically locating an exterior cortical bone margin of the vertebral body; automatically defining a search region of interest (ROI) anterior to the exterior cortical bone; automatically locating the aorta within the search ROI; automatically identifying calcium voxels within the aorta having x-ray attenuation values above a predetermined threshold value; and automatically providing a quantitative measure of calcium.