1. A method for evaluating a three-dimensional image of a laterally-symmetric organ system, comprising the steps of: electronically segmenting a three-dimensional image of a laterally symmetric organ system, to obtain a segmented organ system; electronically deforming said segment organ system to produce an electronically deformed organ system comprising two halves that are mirror-symmetrical with regard to their external shape; electronically determining differences between said mirror-symmetric halves of the deformed organ system by comparing one of said halves with the other of said halves; and visually representing the determined differences between said halves.