Realistic wave-optics simulation of X-ray dark-field imaging at a human scale

Area of Science:

• Medical Imaging
• Computational Physics
• Radiology

Background:

• X-ray dark-field imaging (XDFI) offers superior diagnostic performance compared to conventional X-ray imaging.
• A critical gap exists in tools for simulating human-scale clinical XDFI images.

Purpose of the Study:

• To develop and demonstrate the first human-scale XDFI simulation tool.
• To assess the diagnostic utility of XDFI for various lung conditions, including emphysema, fibrosis, atelectasis, edema, and pneumonia.

Main Methods:

• Augmented the XCAT phantom with Voronoi grids to model lung alveolar substructure.
• Simulated X-ray wave propagation using multi-layer wave-optics.
• Varied material properties and grid parameters to generate XDFI images of healthy and diseased lungs.

Main Results:

• Generated realistic human-scale XDFI images of normal and diseased lungs.
• Confirmed distinct dark-field signals for normal, emphysematous, and fibrotic lungs.
• Observed similar reductions in dark-field signal for pneumonia, edema, and atelectasis due to fluid accumulation, wall thickening, or deflation.

Conclusions:

• Feasible to generate realistic XDFI images of lung pathologies using augmented XCAT and wave optics.
• The simulation framework facilitates in-silico clinical trials.
• Enables optimization of hardware and software for XDFI.