A system for determining a dimension of an anatomical structure using an appropriate set of 2-D slice images obtained by scanning the anatomical structure, the system comprising: assembling apparatus for assembling the set of scanned 2-D slice images into a 3-D database; extracting apparatus for extracting an anatomical feature from the information contained in the 3-D database; specifying apparatus for specifying a measurement to be ade based on the extracted anatomical feature; and calculating apparatus for calculating the measurement so specified.