Patient movement correction method for cone-beam computed tomography

Abstract

A patient movement correction method for cone-beam computed tomography wherein a set of X-ray projection images of the patient is acquired using the X-ray imaging means. An initial projection geometry estimate describing the spatial positions and orientation of the X-ray source and the X-ray detector during the acquisition of an X-ray projection images is defined. An intermediate CBCT reconstruction using the X-ray projection images and the initial projection geometry estimate is computed. Projection-image-specific corrective geometric transformations are determined for the initial projection geometry estimate and the intermediate CBCT reconstruction. A final CBCT reconstruction is computed using the X-ray projection images and a corrected estimate of the projection geometry corresponding to the determined corrective geometric transformations wherein the corrective geometric transformations for the initial projection geometry estimate are determined in a projection-image-specific rotating coordinate system corresponding to the spatial positions and orientations of the X-ray source and X-ray detector during the acquisition of the X-ray projection images.