Monte Carlo Simulation for Polychromatic X-Ray Fluorescence Computed Tomography with Sheet-Beam Geometry

Area of Science:

• Medical Imaging
• Biomedical Engineering
• X-ray Physics

Background:

• Synchrotron-based sheet-beam X-ray fluorescence computed tomography (XFCT) is time-efficient but impractical for most labs.
• Developing practical XFCT systems for biomedical research is crucial.

Purpose of the Study:

• To evaluate the feasibility of polychromatic X-ray fluorescence computed tomography (XFCT) with sheet-beam geometry using Monte Carlo simulations.
• To assess the accuracy of XFCT image reconstruction using a novel discretized imaging model.

Main Methods:

• Monte Carlo simulations using GEANT 4 were performed on two phantoms (A and B) with varying GNP concentrations and sizes.
• XFCT images were reconstructed using Filter Back-Projection (FBP) and Maximum Likelihood Expectation Maximization (MLEM) algorithms.
• Contrast-to-noise ratio (CNR) was calculated to evaluate image quality.

Main Results:

• The study confirmed the feasibility of sheet-beam XFCT with a polychromatic X-ray source.
• The discretized imaging model significantly improved the accuracy of reconstructed XFCT images.
• MLEM with correction yielded better image quality compared to FBP.

Conclusions:

• Sheet-beam XFCT using a polychromatic X-ray source is a viable technique for biomedical research.
• The developed discretized imaging model enhances XFCT image reconstruction accuracy.
• This approach offers a practical alternative for laboratories without access to synchrotrons.