IMPROVED ALIGNMENT OF SHAPES OF BODY PARTS FROM IMAGES

摘要

A method of manipulation of a representation of a 2-D shape for improving a General Procrustes Alignment process, comprising taking a starting 2-D shape defined by a set of landmarks derived from data representing a 2-D projection image of a body part such as a vertebra, in a suitably programmed computing device deriving for each landmark of the 2-D shape a probable relative depth by the application thereto of a statistical model based on a multiplicity of 3-D shapes defined by landmarks derived from 3-D images of similar said body parts, said landmarks having one depth and two spatial coordinates, said model relating the probable relative depth of each landmark in a 3-D-shape of a said body part to the spatial coordinates of the set of landmarks constituting a said shape, and based on the inferred relative depth of the landmarks of the starting 2-D shape deforming the starting 2-D shape to correct for apparent distortion caused by rotation about an axis parallel to the projection plane of the imaged body part, so producing a corrected 2-D shape.