Affiliations: Air Force Early Warning Academy, Wuhan, Hubei, China | National Digital Switching System Engineering and
Technological Research Center, Zhengzhou, Henan, China | The Beijing City Key Lab of Medical Physics and
Engineering, Peking University, Beijing, China
Note: [] Corresponding author: Bin Yan, National Digital Switching System
Engineering and Technological Research Center, Zhengzhou 450002, Henan, China.
E-mail: tom.yan@gmail.com
Abstract: In various applications of computed tomography (CT), it is common
that the reconstructed object is over the field of view (FOV) or we may intend
to sue a FOV which only covers the region of interest (ROI) for the sake of
reducing radiation dose. These kinds of imaging situations often lead to
interior reconstruction problems which are difficult cases in the
reconstruction field of CT, due to the truncated projection data at every view
angle. In this paper, an interior reconstruction method is developed based on a
rotation-translation (RT) scanning model. The method is implemented by first
scanning the reconstructed region, and then scanning a small region outside the
support of the reconstructed object after translating the rotation centre. The
differentiated backprojection (DBP) images of the reconstruction region and the
small region outside the object can be respectively obtained from the two-time
scanning data without data rebinning process. At last, the projection onto
convex sets (POCS) algorithm is applied to reconstruct the interior region.
Numerical simulations are conducted to validate the proposed reconstruction method.
