Patent ID: 6206566
Filing Date: 2001-03-27
Classification: A61B

Abstract:
An X-ray apparatus comprising:an X-ray examination system having an X-ray source which emits an X-ray beam from a focus and an X-ray detector on which said X-ray beam is incident;means for rotating said X-ray examination system around an examination subject while irradiating said examination subject with said X-ray beam from a plurality of different projection angles for obtaining a plurality of 2D projection images of said examination subject respectively as said plurality of different projection angles, each of said 2D projection images having a unique projection geometry associated therewith;means for determining extrinsic imaging parameters and means for determining intrinsic imaging parameters for each of said 2D projection images, said extrinsic imaging parameters identifying a geometric reference point of said X-ray examination system for each of said 2D projection images and said intrinsic imaging parameters identifying a geometric relation between said X-ray source and said X-ray detector for each of said 2D projection images, and means for determining the respective projection geometries for said 2D projection images from said extrinsic imaging parameters and said intrinsic imaging parameters, said means for determining intrinsic imaging parameters comprising a plurality of X-ray positive marks disposed substantially in one plane and in a path of said X-ray beam, said X-ray positive marks being disposed at respective geometric positions relative to each other and relative to said X-ray source which are known; anda computer using said 2D projection images and said projection geometries for constructing a 3D image therefrom of said examination subject.