【作者】 张意； 张卫华； 陈虎； 周激流；

【Author】 ZHANG Yi;ZHANG Weihua;CHEN Hu;ZHOU Jiliu;College of Computer Science,Sichuan University;

【机构】 四川大学计算机学院；

【摘要】 降低辐射剂量能减小对X射线对人体的危害,但是同时会降低CT图像的信噪比,影响图像诊断价值。本文提出一种基于分数阶的自适应统计迭代方法,为了改善全变分正则项的块状效应,构造了基于分数阶微积分的全变分正则项,同时基于局部方差的概念提出了模型参数的自适应控制方式。仿真实验和临床数据实验表明,本文方法在消除低剂量CT图像噪声的同时,可以有效抑制块状效应,保留更多的结构纹理信息,提高CT图像的疾病诊断价值。更多还原

【Abstract】 This work presents a novel Computed Tomography(CT) reconstruction method for the low-dose problem based on fractional calculus.To overcome the disadvantages of the total variation minimization method,we propose a fractional-order total variation based image reconstruction method in this paper.The presented model adopts fractional-order total variation instead of traditional total variation.Different from the traditional total variation,the fractional-order total variation is derived by considering more neighboring image voxels and the corresponding weights can be adaptively determined by the order of the model for the purpose of suppress the over-smoothing effect.The discretization scheme of the fractional-order model is also given.Numerical experiment demonstrates that our method achieves better performance than existing reconstruction methods,including filtered back projection(FBP) and the total variation-based method.更多还原