Finite detector based projection model for high spatial resolution

Article type: Research Article

Authors: Yu, Hengyong^{; ;} | Wang, Ge^{; ;}

Affiliations: Department of Radiology, Division of Radiologic Sciences, Wake Forest University Health Sciences, Winston-Salem, NC, USA | Biomedical Imaging Division, VT-WFU School of Biomedical Engineering and Sciences, Wake Forest University Health Sciences, Winston-Salem, NC, USA | Biomedical Imaging Division, VT-WFU School of Biomedical Engineering and Sciences, Virginia Tech., Blacksburg, VA, USA

Note: [] Corresponding author. E-mail: hengyong-yu@ieee.org

Abstract: For finite detector and focal spot sizes, here we propose a projection model for high spatial resolution. First, for a given x-ray source point, a projection datum is modeled as an area integral over a narrow fan-beam connecting the detector elemental borders and the x-ray source point. Then, the final projection value is expressed as the integral obtained in the first step over the whole focal spot support. An ordered-subset simultaneous algebraic reconstruction technique (OS-SART) is developed using the proposed projection model. In the numerical simulation, our method produces improved spatial resolution and suppresses high-frequency artifacts.

Keywords: Finite detector size, area integral model, line integral model, iterative reconstruction, high spatial resolution

DOI: 10.3233/XST-2012-0331

Journal: Journal of X-Ray Science and Technology, vol. 20, no. 2, pp. 229-238, 2012