CT SCANNER WITH AUTOMATIC DETERMINATION OF VOLUME OF INTEREST

A CT scanner automatically determines a volume of change based upon anatomical changes in a patient. During surgery, the CT scanner takes a sufficient number of two-dimensional initial images using a full field of view. The CT scanner compares the initial images to pre-operative data. Based upon the comparison, the CT scanner automatically determines the volume of change plus some margin to define a volume of interest. The CT scanner then collimates an x-ray source to perform an intra-operative updated CT scan of the volume of interest. The CT scanner updates the pre-operative data with the data from the intra-operative updated CT scan of the volume of interest to form a fully updated three-dimensional CT image. The initial images and the pre-operative data can be taken at a lower resolution than the intra-operative updated CT scan of the volume of interest to reduce the x-ray exposure of the patient.