Cupping artifacts correction for polychromatic X-ray cone-beam computed tomography based on projection compensation and hardening behavior

Abstract

Based on the beam hardening behavior of polychromatic X-ray, the aim of this paper is to address and test an improved experimental and theoretical investigations of the distorted polychromatic projection data to generate high qualified imaging by reducing the cupping artifacts and noise in Cone-Beam computed tomography (CBCT). Since the hardening information has a large relationship with the span that the ray passing through the object, a method of obtaining the lengths that the ray across the binary image is proposed. As the knowledge, a new weighted and compensated correction model is constructed to primarily eliminate cupping artifacts. Finally, studies on polychromatic projection are verified by using pieces on CBCT system. Study results show effective suppression of cupping artifacts of polychromatic projection. For experimental, the root mean square error (RMSE) of the proposed method is reduced by 31.6 %, peak signal to noise ratio (PSNR), and universal quality index (UQI) are increased by 16.8 % and 12.8 % for phantom #Bushing, respectively; which also indicate better uniformity of the results for phantom #Wheel, where the RMSE is reduced by 30.6 %, PSNR and UQI were increased by 19.4 % and 15.9 %, respectively. The proposed algorithm is anticipated to find its utility in industrial nondestructive testing wherein the image reconstruction for the complex geometry and high energy X-ray imaging.