Parallel iterative cone beam CT image reconstruction on a PC cluster

Article type: Research Article

Authors: Li, Xiang | Ni, Jun^; | Wang, Ge^;

Affiliations: Department of Biomedical Engineering, The University of Iowa, Iowa City, IA 52242, USA | Department of Radiology, The University of Iowa, Iowa City, IA 52242, USA | Department of Computer Science, The University of Iowa, Iowa City, IA 52242, USA | Research Services, ITS, The University of Iowa, Iowa City, IA 52242, USA. E-mail: {xiang-li, jun-ni, ge-wang}@uiowa.edu

Abstract: The iterative reconstruction (IR) algorithms are able to generate CT images with higher quality compared with the filtered backprojection method when the projection data is noisy or the radiation dose is low. IR can also be used when the data is incomplete. The major disadvantage of the IR is its high demand on computation and slow reconstruction. To improve the time performance of the IR we parallelized four representative iterative algorithms: EM, SART and their ordered subset (OS) versions on a Linux PC cluster. A micro-forward-back-projector was implemented for increased parallelization. Parameters are cached at the ray level during forward-projection to further reduce time used for back-projection. The speed-up and efficiency factors of our parallel implementation are reported.

Journal: Journal of X-Ray Science and Technology, vol. 13, no. 2, pp. 63-72, 2005