Point spread function modeling and image restoration for cone-beam CT

• Published in: Chinese physics C Vol. 39; no. 3; pp. 101 - 106
• Main Author: 张华 黄魁东 史仪凯 徐哲
• Format: Journal Article
• Language: English
• Published: 01.03.2015
• Subjects: Algorithms; Computer aided tomography; Image restoration; Mathematical models; Point spread functions; Projection; Restoration; 函数模型; 医疗成像; 图像恢复算法; 工业无损检测; 投影图像; 点扩散函数; 计算机断层扫描; 锥束CT
• ISSN: 1674-1137; 0254-3052
• DOI: 10.1088/1674-1137/39/3/038202

X-ray cone-beam computed tomography （CT） has such notable features as high efficiency and precision, and is widely used in the fields of medical imaging and industrial non-destructive testing, but the inherent imaging degradation reduces the quality of CT images. Aimed at the problems of projection image degradation and restoration in cone-beam CT, a point spread function （PSF） modeling method is proposed first. The general PSF model of cone- beam CT is established, and based on it, the PSF under arbitrary scanning conditions can be calculated directly for projection image restoration without the additional measurement, which greatly improved the application convenience of cone-beam CT. Secondly, a projection image restoration algorithm based on pre-filtering and pre-segmentation is proposed, which can make the edge contours in projection images and slice images clearer after restoration, and control the noise in the equivalent level to the original images. Finally, the experiments verified the feasibility and effectiveness of the proposed methods.