A method for generating a 3D reference computer model of at least one anatomical structure for comparison with a selectable pre-, intra- or postoperative set of medical images of at least one anatomical structure, the method including: acquiring at least a first and a second medical image of at least one anatomical structure in a preoperative status from different perspectives using a computer assisted medical imaging device, wherein the first and second medical images are represented by a respective first and second set of digital 2D image data and generating a 3D reference computer model of an anatomical structure by selecting and extracting a 3D atlas model of an anatomical structure to be treated from a generic anatomical atlas provided in the form of a digital data source, and registering at least a section of each of the first and second medical images to the selected 3D atlas model.
