A calibration method for misaligned geometry in cone-beam CT

This paper presents a new method based on interval subdividing for geometric calibration in cone-beam CT system. The proposed method utilizes only experimental data and requires no prior knowledge of the object. The geometric system is parameterized at first and three cost functions which reflect the differences between two images are introduced. Then the relationships between slices from different planes in the reconstruction image and cost functions for different parameters are analyzed. The results show that there exists optimal slice and cost function for a certain parameter. And this method has advantages in high resolution CT. The results of reconstructions demonstrate that this method is able to calibrate the parameters with high accuracy and converge quickly. (authors)