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

Area of Science:

• Medical Imaging
• Computational Physics
• Radiology

Background:

• Conventional X-ray imaging has limitations in diagnosing certain lung pathologies.
• X-ray dark-field imaging (XDFI) shows promise as a superior diagnostic alternative.
• A lack of human-scale simulation tools hinders clinical XDFI development.

Purpose of the Study:

• To develop the first human-scale X-ray dark-field imaging simulation tool.
• To assess the diagnostic capabilities of XDFI for various lung conditions.
• To enable in-silico trials for optimizing XDFI hardware and software.

Main Methods:

• Augmented the XCAT phantom with Voronoi grids to model alveolar substructure.
• Assigned material properties to simulate X-ray wave propagation using multi-layer wave optics.
• Varied grid density/thickness and material properties to simulate normal and diseased lung XDFI.

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 dark-field signal reductions for pneumonia, edema, and atelectasis due to alveolar changes.

Conclusions:

• Human-scale XDFI simulation is feasible using augmented phantoms and wave optics.
• The simulation tool accurately depicts XDFI signals for various lung pathologies.
• This framework supports in-silico clinical trials and XDFI technology advancement.