C-arm X-ray system projection geometry determining method for use during imaging patient, involves determining and storing correct real projection geometry for angulations based on calculated deviations

摘要

The method involves using an ideal model of a C-arm X-ray system as a base with a variable parameter e.g. angulation parameter, and a fixed parameter e.g. distance to ball middle point-detector. Boundary conditions predefined by the X-ray system are determined at a number of angular positions of C-arms (2) using calibrated values of a projection geometry and the variable parameter. Deviations for angular combinations are calculated based on the calibrated values and the model. A correct real projection geometry for angulations is determined and stored based on the calculated deviations.