METHOD FOR EVALUATING AND CORRECTING GEOMETRIC PARAMETERS OF CONE-BEAM CT SYSTEM BASED ON GLOMERULUS MOTIF

摘要

Disclosed is a method for evaluating and correcting geometric parameters of a cone-beam CT system based on a glomerulus motif. The method uses a geometric model, a correction motif, a defined back projection ray convergence degree evaluation index and a geometric parameter solving algorithm to provide a convergence degree evaluation index of a virtual intersecting point of back projection rays, wherein the index can effectively evaluate the reconstruction quality under a current geometric parameter. By means of calculating an evaluation index of geometric parameters and in conjunction with an optimization method, the geometric parameters of a cone-beam CT system can be calculated with high precision, a motif scanning mode is flexible, calculation is convenient, and the requirements of many kinds of cone-beam CT systems for geometric correction precision can be met.