基于三维加权和双域滤波的螺旋CT伪影校正

Helical CT Artifact Correction Based on 3D Weighting and Dual Domain Filtering

摘要:

螺旋CT重建会受到锥束伪影和风车伪影的影响，锥束伪影是由于锥角和螺距过大而导致的，而风车伪影由纵向方向采样不足引起，为了降低锥束伪影与风车伪影对CT图像的影响，提出一种螺旋CT伪影校正算法；首先采用三维加权螺旋FDK算法进行重建，有效去除重建图像中的锥束伪影，然后采用改进的双域滤波算法对含风车伪影图像进行校正；三维加权螺旋FDK算法通过对大锥角的射线给予不利权重来抑制锥束伪影，改进的双域滤波算法可以在去除风车伪影的同时保留更多的细节；计算机仿真实验结果表明，该算法能有效地抑制重建图像中的锥束伪影和风车伪影，提高CT图像的质量。

Abstract:

Helical CT reconstruction is affected by cone beam artifacts and windmill artifacts; cone beam artifacts are caused by excessive cone angle and pitch, while windmill artifacts are caused by insufficient sampling in the longitudinal direction. In order to reduce the effects of cone beam artifacts and windmill artifacts on CT images, a helical CT artifact correction algorithm is proposed; firstly, the 3D weighted helical FDK algorithm is used for reconstruction to effectively remove cone beam artifacts from the reconstructed images. Then an improved dual-domain filtering algorithm is used to correct the images containing windmill artifacts; the 3D weighted helical FDK algorithm suppresses cone beam artifacts by giving unfavorable weights to rays with large cone angles, and the improved dual-domain filtering algorithm can preserve more details while removing windmill artifacts; the computer simulation experimental results show that the algorithm can effectively suppress cone beam artifacts and windmill artifacts in the reconstructed images and improve the CT The results of computer simulation show that the algorithm can effectively suppress the cone beam artifacts and windmill artifacts in the reconstructed images and improve the quality of CT images.