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基于椭球包围盒的锥束CT三维加权重建算法 被引量:5
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作者 杨亚飞 张定华 +2 位作者 黄魁东 时稳龙 张才鑫 《仪器仪表学报》 EI CAS CSCD 北大核心 2016年第11期2563-2571,共9页
提高锥束CT大锥角圆轨道扫描下的重建图像质量一直是CT成像技术的重要研究方向。分析了圆轨道扫描下Radon空间的Z向数据缺失特点和FDK算法的灰度下降规律,提出了一种基于椭球包围盒的锥束CT三维加权重建算法。该算法无需重排,只需利用... 提高锥束CT大锥角圆轨道扫描下的重建图像质量一直是CT成像技术的重要研究方向。分析了圆轨道扫描下Radon空间的Z向数据缺失特点和FDK算法的灰度下降规律,提出了一种基于椭球包围盒的锥束CT三维加权重建算法。该算法无需重排,只需利用投影数据获取重建物体的最小包围盒,并根据其内接椭球的大小和空间位置自动生成三维加权函数,在反投影阶段加入该加权函数即可实现。该算法不会引入其他伪影,计算量增加很小,并且在中心层与FDK算法等价。仿真扫描实验表明,该算法显著提高了FDK算法的准确性,减小了锥角伪影。 展开更多
关键词 FDK算法 数据缺失 灰度下降 椭球包围盒
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Robust scatter correction method for cone-beam CT using an interlacing-slit plate 被引量:1
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作者 黄魁东 徐哲 +2 位作者 张定华 张华 时稳龙 《Chinese Physics C》 SCIE CAS CSCD 2016年第6期95-102,共8页
Cone-beam computed tomography (CBCT) has been widely used in medical imaging and industrial nondestructive testing, but the presence of scattered radiation will cause significant reduction of image quality. In this ... Cone-beam computed tomography (CBCT) has been widely used in medical imaging and industrial nondestructive testing, but the presence of scattered radiation will cause significant reduction of image quality. In this article, a robust scatter correction method for CBCT using an interlacing-slit plate (ISP) is carried out for convenient practice. Firstly, a Gaussian filtering method is proposed to compensate the missing data of the inner scatter image, and simultaneously avoid too-large values of calculated inner scatter and smooth the inner scatter field. Secondly, an interlacing-slit scan without detector gain correction is carried out to enhance the practicality and convenience of the scatter correction method. Finally, a denoising step for scatter-corrected projection images is added in the process flow to control the noise amplification The experimental results show that the improved method can not only make the scatter correction more robust and convenient, but also achieve a good quality of scatter-corrected slice images. 展开更多
关键词 CBCT scatter correction image fusion interlacing-slit noise control
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