为减少低剂量计算机断层扫描(computed tomography,CT)重建图像时出现的大量条形伪影,提出一种基于差分曲率自适应正则化的低剂量CT重建算法。将差分曲率应用到原有的投影域惩罚加权最小二乘法(penalized weight least square,PWLS)中,...为减少低剂量计算机断层扫描(computed tomography,CT)重建图像时出现的大量条形伪影,提出一种基于差分曲率自适应正则化的低剂量CT重建算法。将差分曲率应用到原有的投影域惩罚加权最小二乘法(penalized weight least square,PWLS)中,差分曲率对图像的边缘、平滑区域以及斜坡结构具有良好的检测性能,可有效地控制平滑区域和边缘区域的扩散程度,自适应地去除重建图像中的条形伪影。实验结果表明,该算法能有效抑制条形伪影的产生,较好保持图像的边缘和细节信息。展开更多
Background The differential phase computed tomography(DP-CT)imaging is a kind of X-ray-phase-based CT methods,which is widely used in various X-ray imaging laboratories.At present,a collection of projections with the ...Background The differential phase computed tomography(DP-CT)imaging is a kind of X-ray-phase-based CT methods,which is widely used in various X-ray imaging laboratories.At present,a collection of projections with the horizontal direc-tion(perpendicular to the sample rotation axis)DP information is often acquired in DP-CT.In an ideal experiment,if the background is zero,then we can accurately reconstruct the information of each direction of the sample with horizontal data only.Actually,background information will produce streaking artifacts to affect the resolution in directions other than the horizontal direction.Purpose To mitigate the streaking artifacts in the conventionally reconstructed DP-CT images.Method This study develops a novel analytical DP-CT reconstruction framework by jointly using the bilateral DP information obtained along two perpendicular directions.In addition,a new data acquisition scheme is also proposed to quickly acquire the bilateral DP signal without the need of changing the direction of refraction signal acquisition.Results Experimental results demonstrate that this new algorithm is able to greatly reduce the streaking artifacts on DP-CT images.展开更多
文摘为减少低剂量计算机断层扫描(computed tomography,CT)重建图像时出现的大量条形伪影,提出一种基于差分曲率自适应正则化的低剂量CT重建算法。将差分曲率应用到原有的投影域惩罚加权最小二乘法(penalized weight least square,PWLS)中,差分曲率对图像的边缘、平滑区域以及斜坡结构具有良好的检测性能,可有效地控制平滑区域和边缘区域的扩散程度,自适应地去除重建图像中的条形伪影。实验结果表明,该算法能有效抑制条形伪影的产生,较好保持图像的边缘和细节信息。
文摘Background The differential phase computed tomography(DP-CT)imaging is a kind of X-ray-phase-based CT methods,which is widely used in various X-ray imaging laboratories.At present,a collection of projections with the horizontal direc-tion(perpendicular to the sample rotation axis)DP information is often acquired in DP-CT.In an ideal experiment,if the background is zero,then we can accurately reconstruct the information of each direction of the sample with horizontal data only.Actually,background information will produce streaking artifacts to affect the resolution in directions other than the horizontal direction.Purpose To mitigate the streaking artifacts in the conventionally reconstructed DP-CT images.Method This study develops a novel analytical DP-CT reconstruction framework by jointly using the bilateral DP information obtained along two perpendicular directions.In addition,a new data acquisition scheme is also proposed to quickly acquire the bilateral DP signal without the need of changing the direction of refraction signal acquisition.Results Experimental results demonstrate that this new algorithm is able to greatly reduce the streaking artifacts on DP-CT images.
