Image reconstruction of cone-beam CT for region of interest
锥束CT感兴趣区域图像重建研究

The projection data is often truncated during scanning within the region of interest ROI by cone-beam CT, which results in incompleteness of projection data. Aiming at the problem of image reconstruction from incomplete projection data, this paper proposed ART algorithm based on iteration to reconstruct for ROI. The shortage of ART was its large time of computations and slow reconstruction speed. To improve the reconstruction speed of ART, It proposed a fast parallel image reconstruction method based on multi-core. Firstly, it divided the 3D reconstruction region equally into two blocks by centre plane, and the detector plane too. Then, it calculated the projection data of virtual detector by bilinear interpolation. Finally, imlemented the ART algorithm parallel using multi-thread technique on multi-core platform, and improved the reconstruction speed about 2 times with high precision. On this basis, using ART to reconstruct different ROI of 3D Shepp-Logan phantom by simulation, experimental results show that it is feasible to reconstruct ROI with ART.