A method for segmenting vertebrae in digitized images includes providing a plurality of digitized whole-body images, detecting and segmenting a spinal cord using 3D polynomial spinal model in each of the plurality of images, finding a height of each vertebrae in each image from intensity projections along the spinal cord, and building a parametric model of a vertebrae from the plurality of images. The method further includes providing a new digitized whole-body image including a spinal cord, fitting an ellipse to each vertebrae of the spinal cord to find the major and minor axes, and applying constraints to the major and minor axes in the new image based on the parametric model to segment the vertebrae.