CT图像中金属伪影的快速校正

CT系统由于检测对象含有金属夹杂而使得重建图像中出现金属伪影,影响图像的质量。针对金属伪影,提出一种快速而稳定的校正方法。首先判断金属投影区域,然后对金属投影进行插值,然后重建图像。最后,在重建的图像中插入金属部分,得到完整的重建图像。数值模拟和实际CT系统的实验表明,该方法能有效的消除金属伪影,并能保留金属信息,恢复图像的完整。该算法计算复杂度很小,计算快速,具有较高的实用价值。

Fast correction of metal artifacts in CT images

X-ray CT plays an important role in medical fields,industrial nondestructive tests and public security. In X-ray imaging, metal objects absorb X-rays greatly, which introduces streaks on reconstructed images. In this paper, a fast method for metal artifacts reduction is proposed. Firstly, the metal projection region is identified by reprojecting the metal regions extracted from an initial reconstruction without modification. Secondly, the projection in metal projection regions is interpolated. Thirdly, the image is reconstructed by filtered backprojection algorithm using the modified projection. Finally the metal parts are inserted into the reconstructed image. A numerical simulation and practical experiments have demonstrated that our method rapidly suppressed most of metal artifacts, and reserved metal information. The proposed method has high practical value because of its little computational complexity, rapid implementation, effective reduction of metal artifacts and so on.