Wave optics simulation of grating-based X-ray phase-contrast imaging using 4D Mouse Whole Body (MOBY) phantom

Area of Science:

• Medical Imaging
• Computational Physics
• Biomedical Engineering

Background:

• Grating-based X-ray Phase-Contrast Imaging (GB-XPCI) offers enhanced soft-tissue contrast compared to conventional radiography.
• Accurate numerical simulations are crucial for optimizing GB-XPCI protocols and understanding image formation.
• Previous simulations often lacked the fidelity of wave optics or realistic anatomical models.

Purpose of the Study:

• To demonstrate a realistic simulation of GB-XPCI.
• To utilize wave optics for simulating X-ray propagation.
• To employ the four-dimensional Mouse Whole Body (MOBY) phantom defined with non-uniform rational B-splines (NURBS) for realistic modeling.

Main Methods:

• A full-wave approach simulating X-ray wave propagation from source to detector was implemented.
• The numerical Mouse Whole Body (MOBY) phantom, defined using NURBS, was used for simulation.
• Material properties of adult human tissues were assigned, and Poisson noise was incorporated based on photon flux.

Main Results:

• Intensity images of the MOBY phantom were simulated across eight grating positions.
• Absorption, differential phase, and normalized visibility contrast images were calculated.
• The impact of varying exposure times on image quality was predicted.

Conclusions:

• GB-XPCI can be realistically simulated using a full-wave approach.
• The use of NURBS-defined numerical phantoms like MOBY enhances simulation accuracy.
• This simulation methodology provides a robust tool for advancing GB-XPCI research.