Abstract

Info

Title:: Cone beam computed tomography scatter correction based on rotating collimator

Author(s):: PANG Xiaoning; YU Gang; LI Dengwang; Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Ji’nan 250000, China

Keywords:: ; Keywords: cone beam computed tomography; scatter correction; rotating collimator; Monte Carlo method

Abstract:: Abstract: In view of the great effect of scattering on cone beam computed tomography (CBCT) image quality, a CBCT scatter correction method based on rotating collimator is proposed. A rounded rotating collimator is placed between the radiation source and the phantom. Through the rotation of collimator, the continuous scanning along the axis is achieved and the projected image information of the entire volume image is obtained. And then the scattering region which is estimated using the information of the blocked region in projected image is removed from the projected image. Finally the improved FDK algorithm is used to reconstruct images. The results show that after scatter correction, the mean square error of the CBCT values of reconstructed image decreases from 16.00% to 1.18%, that the cupping artifacts reduces from 14.005% to 0.66%, and that the peak signal-to-noise ratio increases from 16.959 4 to 31.450 0. The image obtained by the projection reconstruction of the water phantom using rotating collimator can effectively suppress the scatter and improve the quality of CBCT image.