Affiliations: Institute of Image Processing & Pattern
Recognition, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P.R.
China | Biomedical Imaging Division, VT-WFU School of
Biomedical Engineering and Science, Virginia Tech., Blacksburg, VA 240601,
USA
Note: [] Corresponding author. Prof. Xuanqin Mou, Institute of Image
Processing & Pattern Recognition, Xi'an Jiaotong University, Xi'an,
Shaanxi, 710049, P.R. China. E-mail: [email protected]
Abstract: The polychromatic spectrum of photons emitted by an X-ray tube in
medical diagnostic CT system brings beam hardening artifact. Although many
correction methods have been developed, it is still the major artifact in
clinical CT imaging. Motivated by CT reconstruction researches benefiting from
mathematical phantoms, one so-called physical mathematical phantom and its
projection simulation are presented in this paper, which are used in
comprehensive evaluation of beam hardening corrections. Due to the inherent
merits as compared to discrete and stochastic simulations, an analytic method
is proposed to simulate the polychromatic projections of FORBILD head phantom.
Firstly, CT-numbers are mapped to material compositions under the precondition
sub-regions represent different human tissues. Second, boundary parameters of
sub-regions are determined by the presented algorithms. Finally, projections
are calculated according to X-ray energy spectrum. For validating the
usefulness of our simulation, several typical correction methods are analyzed
using simulated projections. The performance of every correction is exhibited
distinctly. The analysis results show that there are still the spaces to
improve those correction methods.
